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Sample records for haematococcus pluvialis chlorophyceae

  1. Hyperspectral imaging techniques for the characterization of Haematococcus pluvialis (Chlorophyceae).

    PubMed

    Nogami, Satoru; Ohnuki, Shinsuke; Ohya, Yoshikazu

    2014-10-01

    A hyperspectral imaging camera was combined with a bright-field microscope to investigate the intracellular distribution of pigments in cells of the green microalga Haematococcus pluvialis, a synonym for H. lacustris (Chlorophyceae). We applied multivariate curve resolution to the hyperspectral image data to estimate the pigment contents in culture and revealed that the predicted values were consistent with actual measurements obtained from extracted pigments. Because it was possible to estimate pigment contents in every pixel, the intracellular distribution of the pigments was investigated during various life-cycle stages. Astaxanthin was localized specifically at the eyespot of zoospores in early culture stages. Then, it became widely distributed in cells, but subsequently localized differently than the chl. Integrated with our recently developed image-processing program "HaematoCalMorph," the hyperspectral imaging system was useful for monitoring intracellular distributions of pigments during culture as well as for studying cellular responses under various conditions.

  2. Carotenoid Distribution in Living Cells of Haematococcus pluvialis (Chlorophyceae)

    SciTech Connect

    Collins, Aaron M.; Jones, Howland D. T.; Han, Danxiang; Hu, Qiang; Beechem, Thomas E.; Timlin, Jerilyn A.; Evens, Terence

    2011-09-06

    Haematococcus pluvialis is a freshwater unicellular green microalga belonging to the class Chlorophyceae and is of commercial interest for its ability to accumulate massive amounts of the red ketocarotenoid astaxanthin (3,3'-dihydroxy-β,β-carotene-4,4'-dione). Using confocal Raman microscopy and multivariate analysis, we demonstrate the ability to spectrally resolve resonance–enhanced Raman signatures associated with astaxanthin and β-carotene along with chlorophyll fluorescence. By mathematically isolating these spectral signatures, in turn, it is possible to locate these species independent of each other in living cells of H. pluvialis in various stages of the life cycle. Chlorophyll emission was found only in the chloroplast whereas astaxanthin was identified within globular and punctate regions of the cytoplasmic space. Moreover, we found evidence for β-carotene to be co-located with both the chloroplast and astaxanthin in the cytosol. These observations imply that β-carotene is a precursor for astaxanthin and the synthesis of astaxanthin occurs outside the chloroplast. Finally, our work demonstrates the broad utility of confocal Raman microscopy to resolve spectral signatures of highly similar chromophores in living cells.

  3. Carotenoid Distribution in Living Cells of Haematococcus pluvialis (Chlorophyceae)

    PubMed Central

    Collins, Aaron M.; Jones, Howland D. T.; Han, Danxiang; Hu, Qiang; Beechem, Thomas E.; Timlin, Jerilyn A.

    2011-01-01

    Haematococcus pluvialis is a freshwater unicellular green microalga belonging to the class Chlorophyceae and is of commercial interest for its ability to accumulate massive amounts of the red ketocarotenoid astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione). Using confocal Raman microscopy and multivariate analysis, we demonstrate the ability to spectrally resolve resonance–enhanced Raman signatures associated with astaxanthin and β-carotene along with chlorophyll fluorescence. By mathematically isolating these spectral signatures, in turn, it is possible to locate these species independent of each other in living cells of H. pluvialis in various stages of the life cycle. Chlorophyll emission was found only in the chloroplast whereas astaxanthin was identified within globular and punctate regions of the cytoplasmic space. Moreover, we found evidence for β-carotene to be co-located with both the chloroplast and astaxanthin in the cytosol. These observations imply that β-carotene is a precursor for astaxanthin and the synthesis of astaxanthin occurs outside the chloroplast. Our work demonstrates the broad utility of confocal Raman microscopy to resolve spectral signatures of highly similar chromophores in living cells. PMID:21915307

  4. Carotenoid distribution in living cells of Haematococcus pluvialis (Chlorophyceae).

    PubMed

    Collins, Aaron M; Jones, Howland D T; Han, Danxiang; Hu, Qiang; Beechem, Thomas E; Timlin, Jerilyn A

    2011-01-01

    Haematococcus pluvialis is a freshwater unicellular green microalga belonging to the class Chlorophyceae and is of commercial interest for its ability to accumulate massive amounts of the red ketocarotenoid astaxanthin (3,3'-dihydroxy-β,β-carotene-4,4'-dione). Using confocal Raman microscopy and multivariate analysis, we demonstrate the ability to spectrally resolve resonance-enhanced Raman signatures associated with astaxanthin and β-carotene along with chlorophyll fluorescence. By mathematically isolating these spectral signatures, in turn, it is possible to locate these species independent of each other in living cells of H. pluvialis in various stages of the life cycle. Chlorophyll emission was found only in the chloroplast whereas astaxanthin was identified within globular and punctate regions of the cytoplasmic space. Moreover, we found evidence for β-carotene to be co-located with both the chloroplast and astaxanthin in the cytosol. These observations imply that β-carotene is a precursor for astaxanthin and the synthesis of astaxanthin occurs outside the chloroplast. Our work demonstrates the broad utility of confocal Raman microscopy to resolve spectral signatures of highly similar chromophores in living cells.

  5. LIGHT-INDUCED OIL GLOBULE MIGRATION IN HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE).

    PubMed

    Peled, Ehud; Pick, Uri; Zarka, Aliza; Shimoni, Eyal; Leu, Stefan; Boussiba, Sammy

    2012-10-01

    Astaxanthin-rich oil globules in Haematococcus pluvialis display rapid light-induced peripheral migration that is unique to this organism and serves to protect the photosynthetic system from excessive light. We observed rapid light-induced peripheral migration that is associated with chlorophyll fluorescence quenching, whereas the recovery was slow. A simple assay to follow globule migration, based on chlorophyll fluorescence level has been developed. Globule migration was induced by high intensity blue light, but not by high intensity red light. The electron transport inhibitor dichlorophenyl-dimethylurea did not inhibit globule migration, whereas the quinone analog (dibromo-methyl-isopropylbenzoquinone), induced globule migration even at low light. Actin microfilament-directed toxins, such as cytochalasin B and latrunculin A, inhibited the light-induced globule migration, whereas toxins against microtubules were ineffective. Electron microscopic (EM) imaging confirmed the cytoplasmic localization and peripheral migration of globules upon exposure to very high light (VHL). Scanning EM of freeze-fractured cells also revealed globules within cytoplasmic bridges traversing the chloroplast, presumably representing the pathway of migration. Close alignments of globules with endoplasmic reticulum (ER) membranes were also observed following VHL illumination. We propose that light-induced globule migration is regulated by the redox state of the photosynthetic electron transport system. Possible mechanisms of actin-based globule migration are discussed.

  6. Isolation of a novel oil globule protein from the green alga Haematococcus pluvialis (Chlorophyceae).

    PubMed

    Peled, Ehud; Leu, Stefan; Zarka, Aliza; Weiss, Meira; Pick, Uri; Khozin-Goldberg, Inna; Boussiba, Sammy

    2011-09-01

    Cytoplasmic oil globules of Haematococcus pluvialis (Chlorophyceae) were isolated and analyzed for pigments, lipids and proteins. Astaxanthin appeared to be the only pigment deposited in the globules. Triacyglycerols were the main lipids (more than 90% of total fatty acids) in both the cell-free extract and in the oil globules. Lipid profile analysis of the oil globules showed that relative to the cell-free extract, they were enriched with extraplastidial lipids. A fatty acids profile revealed that the major fatty acids in the isolated globules were oleic acid (18:1) and linoleic acid (18:2). Protein extracts from the globules revealed seven enriched protein bands, all of which were possible globule-associated proteins. A major 33-kDa globule protein was partially sequenced by MS/MS analysis, and degenerate DNA primers were prepared and utilized to clone its encoding gene from cDNA extracted from cells grown in a nitrogen depleted medium under high light. The sequence of this 275-amino acid protein, termed the Haematococcus Oil Globule Protein (HOGP), revealed partial homology with a Chlamydomonas reinhardtii oil globule protein and with undefined proteins from other green algae. The HOGP transcript was barely detectable in vegetative cells, but its level increased by more than 100 fold within 12 h of exposure to nitrogen depletion/high light conditions, which induced oil accumulation. HOGP is the first oil-globule-associated protein to be identified in H. pluvialis, and it is a member of a novel gene family that may be unique to green microalgae.

  7. The role of photorespiration during astaxanthin accumulation in Haematococcus pluvialis (Chlorophyceae).

    PubMed

    Zhang, Chunhui; Zhang, Litao; Liu, Jianguo

    2016-10-01

    Most previous studies on Haematococcus pluvialis have been focused on growth and astaxanthin accumulation. However, the relationships between photorespiration and astaxanthin accumulation have not been clarified. The purpose of this study was to examine the role of photorespiration during the process of astaxanthin accumulation in H. pluvialis. During astaxanthin accumulation, the astaxanthin content was reduced significantly when photorespiration was inhibited by its specific inhibitor, carboxymethoxylamine. The inhibition of photorespiration did not change the dry weight, chlorophyll content and OJIP transients during the incubation; however, the inhibition of photorespiration significantly decreased the photochemistry of photosystem II and total photosynthetic O2 evolution capacity. Moreover, the restriction in photorespiration was synchronized with a decrease of astaxanthin accumulation. These results suggest that the photorespiratory pathway in H. pluvialis can accelerate astaxanthin accumulation. We speculate that photorespiration can enhance astaxanthin accumulation in the following ways: (i) photorespiration directly affects the glycerate-3-phosphate (PGA) level, which is intrinsically related to the accumulation of astaxanthin in H. pluvialis; (ii) the photorespiratory pathway indirectly affects the PGA level by effecting the dark reactions of photosynthesis, which then results in the enhancement of astaxanthin accumulation in H. pluvialis.

  8. Molecular mechanisms of the coordination between astaxanthin and fatty acid biosynthesis in Haematococcus pluvialis (Chlorophyceae).

    PubMed

    Chen, Guanqun; Wang, Baobei; Han, Danxiang; Sommerfeld, Milton; Lu, Yinghua; Chen, Feng; Hu, Qiang

    2015-01-01

    Astaxanthin, a red ketocarotenoid with strong antioxidant activity and high commercial value, possesses important physiological functions in astaxanthin-producing microalgae. The green microalga Haematococcus pluvialis accumulates up to 4% fatty acid-esterified astaxanthin (by dry weight), and is used as a model species for exploring astaxanthin biosynthesis in unicellular photosynthetic organisms. Although coordination of astaxanthin and fatty acid biosynthesis in a stoichiometric fashion was observed in H. pluvialis, the interaction mechanism is unclear. Here we dissected the molecular mechanism underlying coordination between the two pathways in H. pluvialis. Our results eliminated possible coordination of this inter-dependence at the transcriptional level, and showed that this interaction was feedback-coordinated at the metabolite level. In vivo and in vitro experiments indicated that astaxanthin esterification drove the formation and accumulation of astaxanthin. We further showed that both free astaxanthin biosynthesis and esterification occurred in the endoplasmic reticulum, and that certain diacylglycerol acyltransferases may be the candidate enzymes catalyzing astaxanthin esterification. A model of astaxanthin biosynthesis in H. pluvialis was subsequently proposed. These findings provide further insights into astaxanthin biosynthesis in H. pluvialis.

  9. CHLOROPLAST GENETIC TOOL FOR THE GREEN MICROALGAE HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE, VOLVOCALES)(1).

    PubMed

    Gutiérrez, Carla L; Gimpel, Javier; Escobar, Carolina; Marshall, Sergio H; Henríquez, Vitalia

    2012-08-01

    At present, there is strong commercial demand for recombinant proteins, such as antigens, antibodies, biopharmaceuticals, and industrial enzymes, which cannot be fulfilled by existing procedures. Thus, an intensive search for alternative models that may provide efficiency, safety, and quality control is being undertaken by a number of laboratories around the world. The chloroplast of the eukaryotic microalgae Haematococcus pluvialis Flotow has arisen as a candidate for a novel expression platform for recombinant protein production. However, there are important drawbacks that need to be resolved before it can become such a system. The most significant of these are chloroplast genome characterizations, and the development of chloroplast transformation vectors based upon specific endogenous promoters and on homologous targeting regions. In this study, we report the identification and characterization of endogenous chloroplast sequences for use as genetic tools for the construction of H. pluvialis specific expression vectors to efficiently transform the chloroplast of this microalga via microprojectile bombardment. As a consequence, H. pluvialis shows promise as a platform for expressing recombinant proteins for biotechnological applications, for instance, the development of oral vaccines for aquaculture.

  10. AGROBACTERIUM-MEDIATED TRANSFORMATION IN THE GREEN ALGA HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE, VOLVOCALES)(1).

    PubMed

    Kathiresan, S; Chandrashekar, A; Ravishankar, G A; Sarada, R

    2009-06-01

    The first successful Agrobacterium-mediated transformation of the green alga Haematococcus pluvialis Flot. using the binary vectors hosting the genes coding for GUS (β-glucuronidase), GFP (green fluorescent protein), and hpt (hygromycin phosphotransferase) is reported here. Colonies resistant to hygromycin at 10 mg · L(-1) expressed β-glucuronidase. The greenish yellow fluorescence of GFP was observed when the hygromycin-resistant cells were viewed with a fluorescent microscope. PCR was used to successfully amplify fragments of the hpt (407 bp) and GUS (515 bp) genes from transformed cells, while Southern blots indicated the integration of the hygromycin gene into the genome of H. pluvialis. SEM indicated that the cell wall of H. pluvialis was altered on infection with Agrobacterium. The transformation achieved here by Agrobacterium does not need treatment with acetosyringone or the wounding of cells. A robust transformation method for this alga would pave the way for manipulation of many important pathways relevant to the food, pharmaceutical, and nutraceutical industries.

  11. Image-based monitoring system for green algal Haematococcus pluvialis (Chlorophyceae) cells during culture.

    PubMed

    Ohnuki, Shinsuke; Nogami, Satoru; Ota, Shuhei; Watanabe, Koichi; Kawano, Shigeyuki; Ohya, Yoshikazu

    2013-11-01

    The green microalga Haematococcus pluvialis accumulates the red pigment astaxanthin accompanied by morphological changes under stress conditions, including nutrient depletion, continuous light and high temperature. To investigate the physiological state of the algal cells, we developed the digital image-processing software called HaematoCalMorph. The software automatically outputs 25 single-cell measurements of cell morphology and pigments based on color, bright-field microscopic images. Compared with manual inspection, the output values of cell shape were reliable and reproducible. The estimated pigment content fits the values calculated by conventional methods. Using a random forests classifier, we were able to distinguish flagellated cells from immotile cells and detect their transient appearance in culture. By performing principal components analysis, we also successfully monitored time-dependent morphological and colorimetric changes in culture. Thus, combined with multivariate statistical techniques, the software proves useful for studying cellular responses to various conditions as well as for monitoring population dynamics in culture.

  12. SUSCEPTIBILITY AND PROTECTIVE MECHANISMS OF MOTILE AND NON MOTILE CELLS OF HAEMATOCOCCUS PLUVIALIS (CHLOROPHYCEAE) TO PHOTOOXIDATIVE STRESS(1).

    PubMed

    Han, Danxiang; Wang, Junfeng; Sommerfeld, Milton; Hu, Qiang

    2012-06-01

    The life cycle of the unicellular green alga Haematococcus pluvialis consists of motile and nonmotile stages under typical growing conditions. In this study, we observed that motile cells were more susceptible than nonmotile cells to high light, resulting in a decrease in population density and photo-bleaching. Using two Haematococcus strains, CCAP 34/12 (a motile cell dominated strain) and SAG 34/1b (a nonmotile cell dominated strain), as model systems we investigated the cause of cell death and the protective mechanisms of the cells that survived high light. The death of motile cells under high light was attributed to the generation of excess reactive oxygen species (ROS), which caused severe damage to the photosynthetic components and the membrane system. Motile cells were able to dissipate excess light energy by nonphotochemical quenching and to relax ROS production by a partially up-regulated scavenging enzyme system. However, these strategies were not sufficient to protect the motile cells from high light stress. In contrast, nonmotile cells were able to cope with and survive under high light by (i) relaxing the over-reduced photosynthetic electron transport chain (PETC), thereby effectively utilizing PETC-generated NADPH to produce storage starch, neutral lipid, and astaxanthin, and thus preventing formation of excess ROS; (ii) down-regulating the linear electron transport by decreasing the level of cytochrome f; and (iii) consuming excess electrons produced by PSII via a significantly enhanced plastid terminal oxidase pathway.

  13. Cloning, molecular characterization, and phylogeny of two evolutionary distinct glutamine synthetase isoforms in the green microalga Haematococcus pluvialis (Chlorophyceae).

    PubMed

    Reinecke, Diana L; Zarka, Aliza; Leu, Stefan; Boussiba, Sammy

    2016-12-01

    Haematococcus pluvialis (Chlorophyta) is a widely used microalga of great economic potential, yet its molecular genetics and evolution are largely unknown. We present new detailed molecular and phylogenetic analysis of two glutamine synthetase (GS) enzymes and genes (gln) under the Astaxanthin-inducing conditions of light- and nitrogen-stress. Structure analysis identified key residues and confirmed two decameric GS2 holoenzymes, a cytoplasmic enzyme, termed GS2c , and a plastidic form, termed GS2p , due to chloroplast-transit peptides at its N-terminus. Gene expression analysis showed dissociation of mRNA, protein, and enzyme activity levels for both GS2 under different growth conditions, indicating the strong post-transcriptional regulation. Data-mining identified novel and specified published gln genes from Prasinophyceae, Chlorophyta, Trebouxiophyceae, Charophyceae, Bryophyta, Lycopodiophyta, Spermatophyta, and Rhodophyta. Phylogenetic analysis found homologues to the cytosolic GS2c of H. pluvialis in all other photo- and non-photosynthetic Eukaryota. The chloroplastic GS2p was restricted to Chlorophyta, Bryophyta, some Proteobacteria and Fungii; no homologues were identified in Spermatophyta or other Eukaryota. This indicates two independent prokaryotic donors for these two gln genes in H. pluvialis. Combined phylogenetic analysis of GS, chl-b synthase, elongation factor, and light harvesting complex homologues project a newly refined model of Viridiplantae evolution. Herein, a GS1 evolved into the cytosolic GS2c and was passed on to all Eukaryota. Later, the chloroplastic GS2p entered the Archaeplastida lineage via a horizontal gene transfer at the divergence of Chlorophyta and Rhodophyta lineages. GS2p persisted in Chlorophyta and Bryophyta, but was lost during Spermatophyta evolution. These data suggest the revision of GS classification and nomenclature, and extend our understanding of the photosynthetic Eukaryota evolution.

  14. Chlorophyll a and NADPH fluorescence lifetimes in the microalgae Haematococcus pluvialis (Chlorophyceae) under normal and astaxanthin-accumulating conditions.

    PubMed

    Kristoffersen, Arne S; Svensen, Øyvind; Ssebiyonga, Nicolausi; Erga, Svein R; Stamnes, Jakob J; Frette, Øyvind

    2012-10-01

    In vivo fluorescence lifetimes of chlorophyll-a (chl-a) and nicotinamide adenine dinucleotide phosphate (NADPH) were obtained from the green microalgae Haematococcus pluvialis under normal and nutrient-stressed conditions (green stage and red stage, respectively), using two-photon excitation provided by a laser generating pulses in the femtosecond range, and a Leica microscope setup. Analysis of the fluorescence lifetime decay curve revealed two separate lifetime components in all our measurements. A short-lifetime component for chl-a of ~250 ps was completely dominant, contributing more than 90% of overall intensity in both green-stage and red-stage cells. Green-stage cells inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea (DCMU) displayed a significant chl-a lifetime increase for the short component. However, this was not the case for red-stage cells, in which DCMU inhibition did not significantly affect the lifetime. For green-stage cells, we found a short NADPH (free) lifetime component at ~150 ps to be completely dominating, but for red-stage cells, a longer component (protein bound) at ~3 ns contributed as much as 35% of the total intensity. We hypothesize that the long lifetime component of NADPH is connected to photoprotection in the cells and coupled to production of astaxanthin. DCMU does not seem to affect the fluorescence lifetimes of NADPH.

  15. Studies on the genetic variation of the green unicellular alga Haematococcus pluvialis (Chlorophyceae) obtained from different geographical locations using ISSR and RAPD molecular marker.

    PubMed

    Mostafa, Noroozi; Omar, Hishamuddin; Tan, Soon Guan; Napis, Suhaimi

    2011-03-22

    Haematococcus pluvialis (Flotow) is a unicellular green alga, which is considered to be the best astaxanthin-producing organism. Molecular markers are suitable tools for the purpose of finding out genetic variations in organisms; however there have been no studies conducted on ISSR or RAPD molecular markers for this organism. The DNA of 10 different strains of H. pluvialis (four strains from Iran, two strains from Finland, one strain from Switzerland and three strains from the USA) was extracted. A genetic similarity study was carried out using 14 ISSR and 12 RAPD primers. Moreover, the molecular weights of the bands produced ranged from 0.14 to 3.4 Kb. The PCA and dendrogram clustered the H. pluvialis strains into various groups according to their geographical origin. The lowest genetic similarity was between the Iran2 and USA2 strains (0.08) and the highest genetic similarity was between Finland1 and Finland2 (0.64). The maximum numbers of bands produced by the ISSR and RAPD primers were 35 and 6 bands, respectively. The results showed that ISSR and RAPD markers are useful for genetic diversity studies of Haematococcus as they showed geographical discrimination.

  16. Colourful Cultures: Classroom Experiments with the Unicellular Alga Haematococcus pluvialis.

    ERIC Educational Resources Information Center

    Delpech, Roger

    2001-01-01

    Describes an investigation into the photosynthetic potential of the different developmental stages of the green unicellular alga Haematococcus pluvialis. Reviews the biotechnological applications of astaxanthin, the red pigment which can be extracted from Haematococcus pluvialis. (Author/MM)

  17. Colourful Cultures: Classroom Experiments with the Unicellular Alga Haematococcus pluvialis.

    ERIC Educational Resources Information Center

    Delpech, Roger

    2001-01-01

    Describes an investigation into the photosynthetic potential of the different developmental stages of the green unicellular alga Haematococcus pluvialis. Reviews the biotechnological applications of astaxanthin, the red pigment which can be extracted from Haematococcus pluvialis. (Author/MM)

  18. A strategy for promoting astaxanthin accumulation in Haematococcus pluvialis by 1-aminocyclopropane-1-carboxylic acid application.

    PubMed

    Lee, Changsu; Choi, Yoon-E; Yun, Yeoung-Sang

    2016-10-20

    The green algae Haematococcus pluvialis is a freshwater unicellular microalga belonging to Chlorophyceae. It is one of the best natural sources of astaxanthin, a secondary metabolite commonly used as an antioxidant and anti-inflammatory agent. Due to the importance of astaxanthin, various efforts have been made to increase its production. In this study, we attempted to develop a strategy for promoting astaxanthin accumulation in H. pluvialis using 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor of ethylene (normally known as an aging hormone in plants). Our results demonstrated that ACC could enhance the growth of H. pluvialis, thereby promoting astaxanthin accumulation. Therefore, ACC has an indirect influence on astaxanthin production. We further verified the effect of ACC with a direct treatment of ethylene originated from banana peels. These results indicate that ethylene could be applied as an indirect method for enhancing growth and astaxanthin biosynthesis in H. pluvialis.

  19. Cell cycles and proliferation patterns in Haematococcus pluvialis

    NASA Astrophysics Data System (ADS)

    Zhang, Chunhui; Liu, Jianguo; Zhang, Litao

    2016-09-01

    Most studies on Haematococcus pluvialis have been focused on cell growth and astaxanthin accumulation; far less attention has been paid to cell cycles and proliferation patterns. The purpose of this study was to clarify cell cycles and proliferation patterns in H. pluvialis microscopically using a camera and video recorder system. The complicated life history of H. pluvialis can be divided into two stages: the motile stage and the non-motile stage. All the cells can be classified into forms as follows: motile cell, non-motile cell, zoospore and aplanospore. The main cell proliferation, both in the motile phase and non-motile phase in H. pluvialis, is by asexual reproduction. Under normal growth conditions, a motile cell usually produces two, sometimes four, and exceptionally eight zoospores. Under unfavorable conditions, the motile cell loses its flagella and transforms into a non-motile cell, and the non-motile cell usually produces 2, 4 or 8 aplanospores, and occasionally 20-32 aplanospores, which further develop into non-motile cells. Under suitable conditions, the non-motile cell is also able to release zoospores. The larger non-motile cells produce more than 16 zoospores, and the smaller ones produce 4 or 8 zoospores. Vegetative reproduction is by direct cell division in the motile phase and by occasional cell budding in the non-motile phase. There is, as yet, no convincing direct evidence for sexual reproduction.

  20. Cell cycles and proliferation patterns in Haematococcus pluvialis

    NASA Astrophysics Data System (ADS)

    Zhang, Chunhui; Liu, Jianguo; Zhang, Litao

    2017-09-01

    Most studies on Haematococcus pluvialis have been focused on cell growth and astaxanthin accumulation; far less attention has been paid to cell cycles and proliferation patterns. The purpose of this study was to clarify cell cycles and proliferation patterns in H. pluvialis microscopically using a camera and video recorder system. The complicated life history of H. pluvialis can be divided into two stages: the motile stage and the non-motile stage. All the cells can be classified into forms as follows: motile cell, nonmotile cell, zoospore and aplanospore. The main cell proliferation, both in the motile phase and non-motile phase in H. pluvialis, is by asexual reproduction. Under normal growth conditions, a motile cell usually produces two, sometimes four, and exceptionally eight zoospores. Under unfavorable conditions, the motile cell loses its flagella and transforms into a non-motile cell, and the non-motile cell usually produces 2, 4 or 8 aplanospores, and occasionally 20-32 aplanospores, which further develop into non-motile cells. Under suitable conditions, the non-motile cell is also able to release zoospores. The larger non-motile cells produce more than 16 zoospores, and the smaller ones produce 4 or 8 zoospores. Vegetative reproduction is by direct cell division in the motile phase and by occasional cell budding in the non-motile phase. There is, as yet, no convincing direct evidence for sexual reproduction.

  1. Enhanced astaxanthin production from Haematococcus pluvialis using butylated hydroxyanisole.

    PubMed

    Shang, Minmin; Ding, Wei; Zhao, Yongteng; Xu, Jun-Wei; Zhao, Peng; Li, Tao; Ma, Huixian; Yu, Xuya

    2016-10-20

    Haematococcus pluvialis is a promising natural source of high-value antioxidant astaxanthin under stress conditions. Biotic or abiotic elicitors are effective strategies for improving astaxanthin production in H. pluvialis. Butylated hydroxyanisole (BHA) was identified as an effective inducer for H. pluvialis LUGU. Under a treatment of 2mgL(-1) BHA (BHA2), astaxanthin content reached a maximum of 29.03mgg(-1) dry weight (DW) (2.03-fold of that in the control) after 12day of the mid-exponential growth phase. Subsequently, H. pluvialis LUGU was subjected to BHA2 at different growth phases because an appropriate time node for adding elicitors is vital for the entire production to succeed. As a result, the highest astaxanthin content (29.3mgg(-1) DW) was obtained in cells on day 14 (BHA2 14) of the late-exponential growth phase. Furthermore, the samples treated with BHA2 14 and the control group were compared in terms of the transcriptional expression of seven carotenogenesis genes, fatty acid composition, and total accumulated astaxanthin. All selected genes exhibited up-regulated expression profiles, with chy, crtO, and bkt exhibiting higher maximum transcriptional levels than the rest. Oleic acid content increased 33.15-fold, with acp, fad, and kas expression being enhanced on the day when astaxanthin was produced rapidly.

  2. Effects of CO2 enrichment on primary photochemistry, growth and astaxanthin accumulation in the chlorophyte Haematococcus pluvialis.

    PubMed

    Chekanov, K; Schastnaya, E; Solovchenko, A; Lobakova, E

    2017-06-01

    The atmospheric CO2 level is limiting for growth of phototrophic organisms such as microalgae, so CO2 enrichment boosts the growth and photosynthesis of microalgal cultures. Still, excessive CO2 injection might inhibit photosynthesis of microalgae. We investigated the effect of continuous sparging of the cultures of Haematococcus pluvialis BM 1 (IPPAS H-2018) (Chlorophyceae), the richest natural source of the value-added pigment astaxanthin. H. pluvialis cultures with CO2-enriched air-gas mixtures (with CO2 level from the atmospheric to 20%) on growth and astaxanthin accumulation in the microalga. Special attention was paid to photosynthetic activity and non-photochemical excited chlorophyll states quenching in the microalgal cells, which was monitored via chlorophyll fluorescence analysis. We also report on the capability of CO2 capture by H. pluvialis derived from direct measurements of its elemental carbon content. The beneficial effect of the moderately high (5%) CO2 levels on the culture growth and astaxanthin accumulation under stress results in a higher overall astaxanthin productivity. However, increase of the CO2 level to 10% or 20% was deteriorative for growth, photosynthesis and carbon assimilation. The results support the possibility of combining a traditional two-stage H. pluvialis cultivation with CO2 bio-capture although a dilution of the flue gas before its injection is required. Copyright © 2017. Published by Elsevier B.V.

  3. Growth of Haematococcus pluvialis Flotow in alternative media.

    PubMed

    Sipaúba-Tavares, L H; Berchielli-Morais, F A; Scardoeli-Truzzi, B

    2015-11-01

    Current study investigates the effect of two alternative media NPK (20-5-20) fertilizer and NPK plus macrophyte (M+NPK) compared to the commercial medium (WC) under growth rate and physiological parameters in batch culture mode (2-L), and verifies whether the use of fertilizer (NPK) and macrophyte (Eichhornia crassipes) would be a good tool for Haematococcus pluvialis culture in the laboratory. The highest number of cells of H. pluvialis has been reported in NPK medium (5.4 × 105 cells.mL-1) on the 28th day, and in the M+NPK and WC media (4.1 × 105 cells.mL-1 and 2.1 × 105 cells.mL-1) on the 26th day, respectively. Chlorophyll-a contents were significantly higher (p<0.05) in NPK medium (41-102 µg.L-1) and lower in WC and M+NPK media (14-61 µg.L-1). The astaxanthin content was less than 0.04 mg.L-1. Production cost of 10-L of H. pluvialis was low in all media, and NPK and M+NPK media had a cost reduction of 65% and 82%, respectively when compared with commercial medium (WC). The use of a medium based on commercial fertilizer and macrophyte (E. crassipes) produced a new medium formulation that proved to be efficient, at least in batch culture mode, in promoting high density culture of H. pluvialis. NPK and macrophyte (E. crassipes) medium seems to be an adequate alternative to replace the conventional one (WC).

  4. Attached cultivation of Haematococcus pluvialis for astaxanthin production.

    PubMed

    Zhang, Wenduo; Wang, Junfeng; Wang, Jialin; Liu, Tianzhong

    2014-04-01

    Haematococcus pluvialis, the best natural source for astaxanthin, was cultivated with an immobilized biofilm method, viz. "attached cultivation", which was high in photosynthetic efficiency. A practical operational protocol for this "attached cultivation" method was investigated by studying the effects of inoculum density, light intensity, nitrogen quantity as well as medium volume on growth and astaxanthin accumulation. Results indicated the optimized inoculum density and light intensity were 10 g m(-2) and 100 μmol m(-2)s(-1), respectively. The optimized nitrogen supply strategy was circulating ca. 30 L of BG-11 medium with initial sodium nitrate concentration of ca. 1.8mM for 1m(2) of cultivation surface. With this strategy, the maximum astaxanthin productivity reached ca. 160 mg m(-2)d(-1) which is much higher than many other indoor researches. Both of the red and green cells were found in the biofilm with red cells on the top.

  5. Growth of Haematococcus pluvialis Flotow in alternative media.

    PubMed

    Sipaúba-Tavares, L H; Berchielli-Morais, F A; Scardoeli-Truzzi, B

    2015-11-10

    AbstractCurrent study investigates the effect of two alternative media NPK (20-5-20) fertilizer and NPK plus macrophyte (M+NPK) compared to the commercial medium (WC) under growth rate and physiological parameters in batch culture mode (2-L), and verifies whether the use of fertilizer (NPK) and macrophyte (Eichhornia crassipes) would be a good tool for Haematococcus pluvialis culture in the laboratory. The highest number of cells of H. pluvialis has been reported in NPK medium (5.4 × 105cells.mL-1) on the 28thday, and in the M+NPK and WC media (4.1 × 105 cells.mL-1and 2.1 × 105 cells.mL-1) on the 26th day, respectively. Chlorophyll-a contents were significantly higher (p<0.05) in NPK medium (41-102 µg.L-1) and lower in WC and M+NPK media (14-61 µg.L-1). The astaxanthin content was less than 0.04 mg.L-1. Production cost of 10-L of H. pluvialiswas low in all media, and NPK and M+NPK media had a cost reduction of 65% and 82%, respectively when compared with commercial medium (WC). The use of a medium based on commercial fertilizer and macrophyte (E. crassipes) produced a new medium formulation that proved to be efficient, at least in batch culture mode, in promoting high density culture of H. pluvialis. NPK and macrophyte (E. crassipes) medium seems to be an adequate alternative to replace the conventional one (WC).

  6. Label-free hyperspectral nonlinear optical microscopy of the biofuel micro-algae Haematococcus Pluvialis.

    PubMed

    Barlow, Aaron M; Slepkov, Aaron D; Ridsdale, Andrew; McGinn, Patrick J; Stolow, Albert

    2014-10-01

    We consider multi-modal four-wave mixing microscopies to be ideal tools for the in vivo study of carotenoid distributions within the important biofuel microalgae Haematococcus pluvialis. We show that hyperspectral coherent anti-Stokes Raman scattering (CARS) microscopy generates non-invasive, quantitative real-time concentrations maps of intracellular carotenoid distributions in live algae.

  7. Label-free hyperspectral nonlinear optical microscopy of the biofuel micro-algae Haematococcus Pluvialis

    PubMed Central

    Barlow, Aaron M.; Slepkov, Aaron D.; Ridsdale, Andrew; McGinn, Patrick J.; Stolow, Albert

    2014-01-01

    We consider multi-modal four-wave mixing microscopies to be ideal tools for the in vivo study of carotenoid distributions within the important biofuel microalgae Haematococcus pluvialis. We show that hyperspectral coherent anti-Stokes Raman scattering (CARS) microscopy generates non-invasive, quantitative real-time concentrations maps of intracellular carotenoid distributions in live algae. PMID:25360358

  8. The effective photoinduction of Haematococcus pluvialis for accumulating astaxanthin with attached cultivation.

    PubMed

    Wan, Minxi; Hou, Dongmei; Li, Yuanguang; Fan, Jianhua; Huang, Jianke; Liang, Songtao; Wang, Weiliang; Pan, Ronghua; Wang, Jun; Li, Shulan

    2014-07-01

    As the optimal source of astaxanthin, Haematococcus pluvialis was cultured for commercial production of astaxanthin through two continuous phases: cell growth and astaxanthin induction. In this study, the efficiency of an attached system for producing astaxanthin from H. pluvialis was investigated and compared to that of the suspended system (bubble column bioreactor) under various conditions. Results showed that this attached system is more suitable for photoinduction of H. pluvialis than the suspended bioreactor. Under the optimal conditions, the astaxanthin productivity of the attached system was 65.8 mg m(-2)d(-1) and 2.4-fold of that in the suspended system. This attached approach also offers other advantages over suspended systems, such as, producing astaxanthin under a wide range of light intensities and temperatures, saving water, ease to harvest cells, resisting contamination. Therefore, the attached approach can be considered an economical, environmentally friendly and highly-efficient technology for producing astaxanthin from H. pluvialis.

  9. [High throughput screening atrazine chlorohydrolase mutants with enhanced activity through Haematococcus pluvialis expression system].

    PubMed

    Wang, Huizhuan; Chen, Xiwen; Hao, Xiaohua; Chen, Defu

    2011-04-01

    Developing a high-throughput screening method is of great importance for directed evolution of atrazine chlorohydrolase. A mutagenesis library of atzA from Pseudomonas sp. ADP and Arthrobacter sp. AD1 was constructed using error-prone PCR and DNA shuffling. Candidate mutants were screened through Haematococcus pluvialis expression system, using atrazine as selection pressure. Sequence analysis showed that mutations in the obtained 12 mutants with enhanced activity were all point-substitutions and scattered throughout the gene. Enzymatic activity analysis showed that the mutants all had higher activities than that of the wild type. The activities were 1.8-3.6 fold of the wild-type enzyme when cultured in BBM medium with 1 mg/L atrazine, whereas 1.8-2.6 fold with 2 mg/L atrazine. These results indicated that Haematococcus pluvialis expression system is an ideal high throughput screening system for directed evolution of atrazine chlorohydrolase.

  10. Interaction of TGA@CdTe Quantum Dots with an Extracellular Matrix of Haematococcus pluvialis Microalgae Detected Using Surface-Enhanced Raman Spectroscopy (SERS).

    PubMed

    Cepeda-Pérez, Elisa; Aguilar-Hernández, Iris; López-Luke, Tzarara; Piazza, Valeria; Carriles, Ramón; Ornelas-Soto, Nancy; de la Rosa, Elder

    2016-09-01

    The present study reports the localization and interaction of thioglycolic acid (TGA) capped CdTe quantum dots (TGA@CdTe QDs) within the extracellular matrix (ECM) of Haematococcus pluvialis (Chlorophyceae) microalgae (HPM) after an incubation period of 5 min. Changes in the Raman spectrum of HPM induced by the adsorption of the TGA@CdTe QDs are successfully found by using naked gold anisotropic structures as nano-sensors for surface-enhanced Raman scattering (SERS effect). Raman spectroscopy results show that TGA@CdTe QDs interact with the biomolecules present in the ECM. Sample preparation and characterization by complementary techniques such as confocal and electron microscopy are also used to confirm the presence and localization of the nanoparticles in the algae. This research shows new evidence on early accumulation of QDs in plant cells and would further improve our understanding about their environmental impact. © The Author(s) 2016.

  11. Production, extraction, and quantification of astaxanthin by Xanthophyllomyces dendrorhous or Haematococcus pluvialis: standardized techniques.

    PubMed

    Domínguez-Bocanegra, Alma Rosa

    2012-01-01

    For many years, benefits and disadvantages of pigments production either by microalgae or yeasts have been under analysis. In this contribution we shall deal with Xanthophyllomyces dendrorhous (formerly Phaffia rhodozyma) and Haematococcus pluvialis, which are known as major prominent microorganisms able to synthesize astaxanthin pigment. Then, the usual trend is to look for optimal conditions to conduct astaxanthin synthesis. From one side, pigment production by H. pluvialis is promoted under cellular stress conditions like nutrient deprivation, exposition to high light intensity, aeration. On the other side, X. dendrorhous is able to show significant increase in astaxanthin synthesis when grown in natural carbon sources like coconut milk, grape juice. The main aim of this chapter is to describe optimal environmental conditions for astaxanthin production by X. dendrorhous or H. pluvialis.

  12. Effects of astaxanthin-rich Haematococcus pluvialis extract on cognitive function: a randomised, double-blind, placebo-controlled study.

    PubMed

    Katagiri, Mikiyuki; Satoh, Akira; Tsuji, Shinji; Shirasawa, Takuji

    2012-09-01

    In this study we tried to confirm the effect of an astaxanthin-rich Haematococcus pluvialis extract on cognitive function in 96 subjects by a randomised double-blind placebo-controlled study. Healthy middle-aged and elderly subjects who complained of age-related forgetfulness were recruited. Ninety-six subjects were selected from the initial screen, and ingested a capsule containing astaxanthin-rich Haematococcus pluvialis extract, or a placebo capsule for 12 weeks. Somatometry, haematology, urine screens, and CogHealth and Groton Maze Learning Test were performed before and after every 4 weeks of administration. Changes in cognitive performance and the safety of astaxanthin-rich Haematococcus pluvialis extract administration were evaluated. CogHealth battery scores improved in the high-dosage group (12 mg astaxanthin/day) after 12 weeks. Groton Maze Learning Test scores improved earlier in the low-dosage (6 mg astaxanthin/day) and high-dosage groups than in the placebo group. The sample size, however, was small to show a significant difference in cognitive function between the astaxanthin-rich Haematococcus pluvialis extract and placebo groups. No adverse effect on the subjects was observed throughout this study. In conclusion, the results suggested that astaxanthin-rich Haematococcus pluvialis extract improves cognitive function in the healthy aged individuals.

  13. Temperature and irradiance impacts on the growth, pigmentation and photosystem II quantum yield of Haemotococcus pluvialis (Chlorophyceae)

    USDA-ARS?s Scientific Manuscript database

    The microalga Haematococcus pluvialis Flotow has been the subject of a number of studies concerned with maximizing astaxanthin production for use in animal feeds and for human consumption. Several of these studies have specifically attempted to ascertain the optimal temperature and irradiance combi...

  14. Cloning and transcription analysis of the nitrate reductase gene from Haematococcus pluvialis.

    PubMed

    Hou, Lu-Lu; Liu, Feng; Zang, Xiaonan; Zhang, Xuecheng; He, Bangxiang; Ding, Yating; Song, Xinwei; Xiao, Dongfang; Wang, Haitao

    2017-04-01

    To optimize the cultivation media for the growth rate of Haematococcus pluvialis and to study the transcription regulation of the algal nitrate reductase (NR), a key enzyme for nitrogen metabolism. The NR gene from H. pluvialis hd7 consists of 5636 nucleotides, including 14 introns. The cDNA ORF is 2718 bp, encoding a 905 aa protein with three conserved domains. The NR amino acids of H. pluvialis hd7 are hydrophilic and have similarity of 72% compared to that of Dunaliella. NR transcription increased with an increase of nitrate concentration from 0.4 to 1 g/l. A deficiency of nitrogen increased NR transcription significantly. The transcription level of NR increased at phosphorus concentrations from 0.08 to 0.2 g/l, with a maximum at 0.08 g/l. The optimum parameters of medium component for transcription of NR and growth of H. pluvialis were 0.3 g NaNO3/l, 0.045 g KH2PO4/l and 1.08 g sodium acetate/l. This study provides a better understanding of nitrate regulation in H. pluvialis.

  15. Enhancement of astaxanthin production using Haematococcus pluvialis with novel LED wavelength shift strategy.

    PubMed

    Xi, Tianqi; Kim, Dae Geun; Roh, Seong Woon; Choi, Jong-Soon; Choi, Yoon-E

    2016-07-01

    Haematococcus pluvialis is a green microalga of particular interest, since it is considered the best potential natural source of astaxanthin, which is widely used as an additive for natural pigmentation. In addition, astaxanthin has recently garnered commercial interest as a nutraceutical, cosmetic, and pharmaceutical. However, producing astaxanthin from H. pluvialis necessitates separation with distinctive culture conditions, dividing between the microalgae growth and the astaxanthin production stages. Light-emitting diodes (LEDs) have emerged as a replacement for traditional light sources, and LED applications are now rapidly expanding to multiple areas in fields such as biotechnology. However, further detail application into microalgae biotechnology remains limited. In this study, we have attempted to establish new protocols based on the specific wavelength of LEDs for the cultivation and production of astaxanthin using H. pluvialis. Specifically, we applied red LEDs for microalgae cell growth and then switched to blue LEDs to induce astaxanthin biosynthesis. The result showed that astaxanthin productions based on a wavelength shift from red to blue were significantly increased, compared to those with continuous illumination using red LEDs. Furthermore, additional increase of astaxanthin production was achieved with simultaneous application of exogenous carbon with blue LED illumination. Our approach based on the proper manipulation of LED wavelengths upon H. pluvialis cell stages will enable the improvement of biomass and enhance astaxanthin production using H. pluvialis.

  16. A rapid and high-quality method for total RNA isolation from Haematococcus pluvialis.

    PubMed

    Luo, Q L; Wang, K P; Xiao, K; Wang, C G; Hu, Z L

    2017-04-13

    Haematococcus pluvialis, as the most potential natural source of astaxanthin, which is a powerful antioxidant with high economic value, has attracted more and more scientific attention in recent years. An in-depth understanding of the mechanism for how H. pluvialis produces astaxanthin requires the intensive investigations on its genetic information. In particular, many reported studies were based on a variety of RNA analyses. However, it is difficult to extract RNA with high quality and quantity from H. pluvialis, because of the blockage from its thick cell wall and contamination by a large quantity of pigments, polysaccharides, and lipids. Therefore, we proposed an optimized Trizol-based RNA extraction method for H. pluvialis by investigating the effect of cell wall broken ways, algal strains, and cell growth status on total RNA isolation. Using this rapid, convenient, and cost-saving method, isolated H. pluvialis RNA had high quantity and quality (with an RNA integrity number of 7.0 and a concentration of 1604.1 ng/μL) equivalent to that isolated by commercial kit, enabling its applications into downstream RNA analyses.

  17. Enhancement of cell biomass and cell activity of astaxanthin-rich Haematococcus pluvialis.

    PubMed

    Sun, Han; Kong, Qing; Geng, Zhaoyan; Duan, Liangfei; Yang, Min; Guan, Bin

    2015-06-01

    Fed-batch culture and the transformation conditions of Haematococcus pluvialis in a 5L photobioreactor were investigated. Methods of feeding model, low temperature at night and proper feeding time were used to increase both cell biomass and cell activity. Dry cell weight of 1.87 g/L which was 2.0-fold of batch culture and the specific growth rate of 0.43 d(-1) suggested the superduper results of these methods to increase the dry cell weight in the short cultivation time. Furthermore, mixed lights of blue and white (ratio of 3:1) at 7000 xl were used to expedite the morphologic changes of H. pluvialis from green cells to red cyst cells with the yield of 91.8±2.53 mg/L.

  18. Sequential Heterotrophy-Dilution-Photoinduction Cultivation of Haematococcus pluvialis for efficient production of astaxanthin.

    PubMed

    Wan, Minxi; Zhang, Zhen; Wang, Jun; Huang, Jianke; Fan, Jianhua; Yu, Anquan; Wang, Weiliang; Li, Yuanguang

    2015-12-01

    A novel cultivation strategy called "Sequential Heterotrophy-Dilution-Photoinduction" was successfully applied in the cultivation of Haematococcus pluvialis to produce astaxanthin effectively. Cells were first cultivated heterotrophically to achieve a high cell density, then were diluted to a suitable concentration and switched to a favorable environment for cells acclimation. Finally, the culture was transferred to high light environment for astaxanthin accumulation. By this strategy, the dry cell weight of 26 g/L and biomass productivity of 64.1mg/L/h were obtained in heterotrophy stage which surpassed ever before reported in literatures. Meanwhile, the cells could accumulate considerable astaxanthin up to 4.6% of dry cell weight after 10 days of photoinduction. Furthermore, the application prospects of the strategy were confirmed further by outdoor experiments. Therefore, this novel strategy provided a promising approach for high-efficient production of natural astaxanthin from H. pluvialis to meet the huge demand of this high value product.

  19. Astaxanthin-Producing Green Microalga Haematococcus pluvialis: From Single Cell to High Value Commercial Products.

    PubMed

    Shah, Md Mahfuzur R; Liang, Yuanmei; Cheng, Jay J; Daroch, Maurycy

    2016-01-01

    Many species of microalgae have been used as source of nutrient rich food, feed, and health promoting compounds. Among the commercially important microalgae, Haematococcus pluvialis is the richest source of natural astaxanthin which is considered as "super anti-oxidant." Natural astaxanthin produced by H. pluvialis has significantly greater antioxidant capacity than the synthetic one. Astaxanthin has important applications in the nutraceuticals, cosmetics, food, and aquaculture industries. It is now evident that, astaxanthin can significantly reduce free radicals and oxidative stress and help human body maintain a healthy state. With extraordinary potency and increase in demand, astaxanthin is one of the high-value microalgal products of the future.This comprehensive review summarizes the most important aspects of the biology, biochemical composition, biosynthesis, and astaxanthin accumulation in the cells of H. pluvialis and its wide range of applications for humans and animals. In this paper, important and recent developments ranging from cultivation, harvest and postharvest bio-processing technologies to metabolic control and genetic engineering are reviewed in detail, focusing on biomass and astaxanthin production from this biotechnologically important microalga. Simultaneously, critical bottlenecks and major challenges in commercial scale production; current and prospective global market of H. pluvialis derived astaxanthin are also presented in a critical manner. A new biorefinery concept for H. pluvialis has been also suggested to guide toward economically sustainable approach for microalgae cultivation and processing. This report could serve as a useful guide to present current status of knowledge in the field and highlight key areas for future development of H. pluvialis astaxanthin technology and its large scale commercial implementation.

  20. Astaxanthin-Producing Green Microalga Haematococcus pluvialis: From Single Cell to High Value Commercial Products

    PubMed Central

    Shah, Md. Mahfuzur R.; Liang, Yuanmei; Cheng, Jay J.; Daroch, Maurycy

    2016-01-01

    Many species of microalgae have been used as source of nutrient rich food, feed, and health promoting compounds. Among the commercially important microalgae, Haematococcus pluvialis is the richest source of natural astaxanthin which is considered as “super anti-oxidant.” Natural astaxanthin produced by H. pluvialis has significantly greater antioxidant capacity than the synthetic one. Astaxanthin has important applications in the nutraceuticals, cosmetics, food, and aquaculture industries. It is now evident that, astaxanthin can significantly reduce free radicals and oxidative stress and help human body maintain a healthy state. With extraordinary potency and increase in demand, astaxanthin is one of the high-value microalgal products of the future.This comprehensive review summarizes the most important aspects of the biology, biochemical composition, biosynthesis, and astaxanthin accumulation in the cells of H. pluvialis and its wide range of applications for humans and animals. In this paper, important and recent developments ranging from cultivation, harvest and postharvest bio-processing technologies to metabolic control and genetic engineering are reviewed in detail, focusing on biomass and astaxanthin production from this biotechnologically important microalga. Simultaneously, critical bottlenecks and major challenges in commercial scale production; current and prospective global market of H. pluvialis derived astaxanthin are also presented in a critical manner. A new biorefinery concept for H. pluvialis has been also suggested to guide toward economically sustainable approach for microalgae cultivation and processing. This report could serve as a useful guide to present current status of knowledge in the field and highlight key areas for future development of H. pluvialis astaxanthin technology and its large scale commercial implementation. PMID:27200009

  1. Effects of some parameters in upscale culture of Haematococcus pluvialis Flotow.

    PubMed

    Sipaúba-Tavares, L H; Millan, R N; Berchielli-Morais, F A

    2013-08-01

    Growth rate and medium parameters between two bench scale volumes (13-L and 250-L) were compared. Experiments were maintained batch mode and culture parameters were periodically measured during a 13-day period. Culture growth during the cultivation of algae Haematococcus pluvialis was determined qualitatively by cell counting, optical density, dry weight, ash content, amount of chlorophyll-a, total organic carbon content and by direct measuring of medium nutrients and some abiotic aspects. Vegetative cell growth was higher when cultured in 13-L with 1.33 x 10(5) cells.mL(-1) on the 12th day than when cultured in 250-L. Significant difference (p < 0.05) in the biology and water culture of H. pluvialis, with the exception of dry weight, ash, nitrite and ammonia, was reported between the volumes. Data obtained in current study for the upscale culture maintenance of H. pluvialis in laboratory conditions shows that it should be undertaken in a 13-L volume due to a greater time span of cells in a vegetative state, greater cell density, lipids and chlorophyll-a contents. Light was of paramount importance on the direct performance of H. pluvialis on the algal biological conditions.

  2. Effects of selenite on green microalga Haematococcus pluvialis: Bioaccumulation of selenium and enhancement of astaxanthin production.

    PubMed

    Zheng, Yihong; Li, Ze; Tao, Ming; Li, Jiancheng; Hu, Zhangli

    2017-02-01

    Algae are at a low trophic level and play a crucial role in aquatic food webs. They can uptake and accumulate the trace element selenium (Se), which can be either essential or toxic to algal growth depending on the dosage and species. Se toxicity and algae resistance varied across different organisms. In order to investigate the effects of Se on the unicellular green alga Haematococcus pluvialis, an important industrial resource for natural astaxanthin, the algal growth rate, chlorophyll content, and fluorescence parameters were derived from experimental treatment with different concentrations of selenite. The results showed that the EC50 for the algal growth rate was 24mg/L, and that a low dosage of selenite (3mg/L) may not hinder H. pluvialis cell growth, but selenite at levels higher than 13mg/L do restrain cell growth. Bioaccumulation experiments showed that H. pluvialis accumulated up to 646μg/g total Se and 380μg/g organic Se, dry weight. However, treatment with high concentrations of selenite significantly increased intracellular hydrogen peroxide levels, antioxidant enzyme activity, and the production of astaxanthin, suggesting that Se bioaccumulation might be toxic to H. pluvialis.

  3. Optimization of culture medium for the continuous cultivation of the microalga Haematococcus pluvialis.

    PubMed

    Fábregas, J; Domínguez, A; Regueiro, M; Maseda, A; Otero, A

    2000-05-01

    The freshwater microalga Haematococcus pluvialis is one of the best microbial sources of the carotenoid astaxanthin, but this microalga shows low growth rates and low final cell densities when cultured with traditional media. A single-variable optimization strategy was applied to 18 components of the culture media in order to maximize the productivity of vegetative cells of H. pluvialis in semicontinuous culture. The steady-state cell density obtained with the optimized culture medium at a daily volume exchange of 20% was 3.77 x 10(5) cells ml(-1), three times higher than the cell density obtained with Bold basal medium and with the initial formulation. The formulation of the optimal Haematococcus medium (OHM) is (in g l(-1)) KNO3 0.41, Na2HPO4 0.03, MgSO4 x 7H2O 0.246, CaCl2 x 2H2O 0.11, (in mg l(-1)) Fe(III)citrate x H2O 2.62, CoCl2 x 6H2O 0.011, CuSO4 x 5H2O 0.012, Cr2O3 0.075, MnCl2 x 4H2O 0.98, Na2MoO4 x 2H2O 0.12, SeO2 0.005 and (in microg l(-1)]) biotin 25, thiamine 17.5 and B12 15. Vanadium, iodine, boron and zinc were demonstrated to be non-essential for the growth of H. pluvialis. Higher steady-state cell densities were obtained by a three-fold increase of all nutrient concentrations but a high nitrate concentration remained in the culture medium under such conditions. The high cell productivities obtained with the new optimized medium can serve as a basis for the development of a two-stage technology for the production of astaxanthin from H. pluvialis.

  4. Rapid screening astaxanthin-hyperproducing Haematococcus pluvialis mutants through near-infrared spectroscopy.

    PubMed

    Liu, J H; Song, L; Huang, Q

    2016-02-01

    The unicellular freshwater green microalga Haematococcus pluvialis is the richest source of natural astaxanthin. Since accumulation of astaxanthin differs significantly among various algal strains at different stages, it is therefore critical to develop an effective high-throughput assay for rapid screening astaxanthin-hyperproducing strains. In the present study, near-infrared spectroscopy (NIRS) in combination with biochemical assay was employed for evaluation of the wide-type H. Pluvialis strains. The partial least squares (PLS) models of total biomass, astaxanthin content and astaxanthin expressed as a percentage of dry weight (DW) were developed with the R(2) values as 0·959, 0·982 and 0·952, the prediction correlation factor (r) values as 0·979, 0·988 and 0·966, and the residual predictive deviation (RPD) values as 4·88, 6·22 and 3·86, respectively. Furthermore, the PLS models were employed to evaluate H. pluvialis mutants, with the r values as 0·973, 0·983 and 0·976, and the RPD values as 3·45, 7·59 and 4·07, respectively. This work thus demonstrates that NIRS is an easy, fast and non-invasive approach that can be applied in high-throughput screening of astaxanthin-hyperproducing algal mutants. Haematococcus pluvialis has potential application for its ability to accumulate natural antioxidant astaxanthin. In this study, we initiated the application of near-infrared spectroscopy (NIRS) in the analysis of total biomass and astaxanthin content of different mutant strains, demonstrating that NIRS can be very useful in the screening of axataxanthin-hyperproducing mutant strains. © 2015 The Society for Applied Microbiology.

  5. Response Surface Methodology for Ultrasound-Assisted Extraction of Astaxanthin from Haematococcus pluvialis

    PubMed Central

    Zou, Tang-Bin; Jia, Qing; Li, Hua-Wen; Wang, Chang-Xiu; Wu, Hong-Fu

    2013-01-01

    Astaxanthin is a novel carotenoid nutraceutical occurring in many crustaceans and red yeasts. It has exhibited various biological activities including prevention or amelioration of cardiovascular disease, gastric ulcer, hypertension, and diabetic nephropathy. In this study, ultrasound-assisted extraction was developed for the effective extraction of astaxanthin from Haematococcus pluvialis. Some parameters such as extraction solvent, liquid-to-solid ratio, extraction temperature, and extraction time were optimized by single-factor experiment and response surface methodology. The optimal extraction conditions were 48.0% ethanol in ethyl acetate, the liquid-to-solid ratio was 20:1 (mL/g), and extraction for 16.0 min at 41.1 °C under ultrasound irradiation of 200 W. Under optimal conditions, the yield of astaxanthin was 27.58 ± 0.40 mg/g. The results obtained are beneficial for the full utilization of Haematococcus pluvialis, which also indicated that ultrasound-assisted extraction is a very useful method for extracting astaxanthin from marine life. PMID:23697948

  6. Repeated cultivation: non-cell disruption extraction of astaxanthin for Haematococcus pluvialis

    PubMed Central

    Sun, Han; Guan, Bin; Kong, Qing; Geng, Zhaoyan; Wang, Ni

    2016-01-01

    The operation of cell disruption is indispensable but cost much in microalgae industry. To be simplified, two different reaction mechanisms await in the cell to respond to moderated or stressed environment. The physical and chemical changes of enzyme and turgor pressure of cell in this conversion play an important role in the enhancement of biomass and metabolites. Repeated turgor pressure (based on the structure and mechanics of cell wall) and converted enzyme system (based on photosynthesis) were used to loosen cell wall and then repeated cultivation of Haematococcus pluvialis for astaxanthin extraction was proposed. There was no significant difference of extraction yield between the broken cell (94.75 ± 3.13%) and non-broken cell (92.32 ± 3.24%) treated by the repeated cultivation. Meanwhile, fed-batch culture according to the relationship among pH and nutrient concentration was used to enhance the biomass of Haematococcus pluvialis with the dry cell weight of 1.63 ± 0.07 g/L. PMID:26838183

  7. Response surface methodology for ultrasound-assisted extraction of astaxanthin from Haematococcus pluvialis.

    PubMed

    Zou, Tang-Bin; Jia, Qing; Li, Hua-Wen; Wang, Chang-Xiu; Wu, Hong-Fu

    2013-05-21

    Astaxanthin is a novel carotenoid nutraceutical occurring in many crustaceans and red yeasts. It has exhibited various biological activities including prevention or amelioration of cardiovascular disease, gastric ulcer, hypertension, and diabetic nephropathy. In this study, ultrasound-assisted extraction was developed for the effective extraction of astaxanthin from Haematococcus pluvialis. Some parameters such as extraction solvent, liquid-to-solid ratio, extraction temperature, and extraction time were optimized by single-factor experiment and response surface methodology. The optimal extraction conditions were 48.0% ethanol in ethyl acetate, the liquid-to-solid ratio was 20:1 (mL/g), and extraction for 16.0 min at 41.1 °C under ultrasound irradiation of 200 W. Under optimal conditions, the yield of astaxanthin was 27.58 ± 0.40 mg/g. The results obtained are beneficial for the full utilization of Haematococcus pluvialis, which also indicated that ultrasound-assisted extraction is a very useful method for extracting astaxanthin from marine life.

  8. Repeated cultivation: non-cell disruption extraction of astaxanthin for Haematococcus pluvialis.

    PubMed

    Sun, Han; Guan, Bin; Kong, Qing; Geng, Zhaoyan; Wang, Ni

    2016-02-03

    The operation of cell disruption is indispensable but cost much in microalgae industry. To be simplified, two different reaction mechanisms await in the cell to respond to moderated or stressed environment. The physical and chemical changes of enzyme and turgor pressure of cell in this conversion play an important role in the enhancement of biomass and metabolites. Repeated turgor pressure (based on the structure and mechanics of cell wall) and converted enzyme system (based on photosynthesis) were used to loosen cell wall and then repeated cultivation of Haematococcus pluvialis for astaxanthin extraction was proposed. There was no significant difference of extraction yield between the broken cell (94.75 ± 3.13%) and non-broken cell (92.32 ± 3.24%) treated by the repeated cultivation. Meanwhile, fed-batch culture according to the relationship among pH and nutrient concentration was used to enhance the biomass of Haematococcus pluvialis with the dry cell weight of 1.63 ± 0.07 g/L.

  9. Effects of Haematococcus pluvialis supplementation on antioxidant system and metabolism in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Sheikhzadeh, Najmeh; Tayefi-Nasrabadi, Hossein; Oushani, Ali Khani; Enferadi, Mohammad Hamed Najafi

    2012-04-01

    Effects of commercial source for astaxanthin (Haematococcus pluvialis) (H.p) on antioxidant power, specific marker enzymes, and some metabolites were examined in rainbow trout (Oncorhynchus mykiss). Fish were fed on diets containing 1, 3, and 10 g microalga kg(-1) feed for 30 days. Serum total antioxidant activity and lipid peroxidation product, indicated by malondialdehyde (MDA), significantly enhanced with different doses of administration, indicating the elevated antioxidant status in all treatment groups. In group fed with high dose of alga, significantly elevated aspartate aminotransferase activity (AST) was noted, indicating damage of normal liver function in this group. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were not affected in all groups. Although serum total protein remained unaffected, serum glucose level was decreased significantly in lower doses of administration. Furthermore, triglyceride and cholesterol levels showed significant decrease in 3 g kg(-1) microalga group by modulation of lipid metabolism in this group. On the other hand, in highest dose, significant increase in lipids was observed, indicating the slight dysfunction in lipid metabolism in this treatment group. The present study suggests that Haematococcus pluvialis especially in dose of 3 g kg(-1) feed administration may effectively enhance the antioxidant system and some biochemical parameters in rainbow trout.

  10. Transcriptome Analysis in Haematococcus pluvialis: Astaxanthin Induction by Salicylic Acid (SA) and Jasmonic Acid (JA).

    PubMed

    Gao, Zhengquan; Li, Yan; Wu, Guanxun; Li, Guoqiang; Sun, Haifeng; Deng, Suzhen; Shen, Yicheng; Chen, Guoqiang; Zhang, Ruihao; Meng, Chunxiao; Zhang, Xiaowen

    2015-01-01

    Haematococcus pluvialis is an astaxanthin-rich microalga that can increase its astaxanthin production by salicylic acid (SA) or jasmonic acid (JA) induction. The genetic transcriptome details of astaxanthin biosynthesis were analyzed by exposing the algal cells to 25 mg/L of SA and JA for 1, 6 and 24 hours, plus to the control (no stress). Based on the RNA-seq analysis, 56,077 unigenes (51.7%) were identified with functions in response to the hormone stress. The top five identified subcategories were cell, cellular process, intracellular, catalytic activity and cytoplasm, which possessed 5600 (~9.99%), 5302 (~9.45%), 5242 (~9.35%), 4407 (~7.86%) and 4195 (~7.48%) unigenes, respectively. Furthermore, 59 unigenes were identified and assigned to 26 putative transcription factors (TFs), including 12 plant-specific TFs. They were likely associated with astaxanthin biosynthesis in Haematococcus upon SA and JA stress. In comparison, the up-regulation of differential expressed genes occurred much earlier, with higher transcript levels in the JA treatment (about 6 h later) than in the SA treatment (beyond 24 h). These results provide valuable information for directing metabolic engineering efforts to improve astaxanthin biosynthesis in H. pluvialis.

  11. Stability and changes in astaxanthin ester composition from Haematococcus pluvialis during storage

    NASA Astrophysics Data System (ADS)

    Miao, Fengping; Geng, Yahong; Lu, Dayan; Zuo, Jincheng; Li, Yeguang

    2013-11-01

    In this paper, we investigated the effects of temperature, oxygen, antioxidants, and corn germ oil on the stability of astaxanthin from Haematococcus pluvialis under different storage conditions, and changes in the composition of astaxanthin esters during storage using high performance liquid chromatography and spectrophotometry. Oxygen and high temperatures (22-25°C) significantly reduced the stability of astaxanthin esters. Corn germ oil and antioxidants (ascorbic acid and vitamin E) failed to protect astaxanthin from oxidation, and actually significantly increased the instability of astaxanthin. A change in the relative composition of astaxanthin esters was observed after 96 weeks of long-term storage. During storage, the relative amounts of free astaxanthin and astaxanthin monoesters declined, while the relative amount of astaxanthin diesters increased. Thus, the ratio of astaxanthin diester to monoester increased, and this ratio could be used to indicate if astaxanthin esters have been properly preserved. If the ratio is greater than 0.2, it suggests that the decrease in astaxanthin content could be higher than 20%. Our results show that storing algal powder from H. pluvialis or other natural astaxanthin products under vacuum and in the dark below 4°C is the most economical and applicable storage method for the large-scale production of astaxanthin from H. pluvialis. This storage method can produce an astaxanthin preservation rate of at least 80% after 96 weeks of storage.

  12. [Effect of silencing lycB gene on the carotenoid synthesis in Haematococcus pluvialis].

    PubMed

    Gong, Wen-Fang; Lu, Li-Jing; Liu, Xin; Chen, Xi-Wen; Chen, De-Fu

    2013-02-01

    Haematococcus pluvialis is a freshwater planktonic single-cell microalgae. It will accumulate high amount of carotenoids under unfavorable environmental conditions. As one of carotenoids, lycopene is an important intermediate in the carotenoid biosynthesis pathway. Lycopene β-cyclase (LycB) is the key enzyme that catalyzes the circularization of lycopene to form β-carotene. In this study, we constructed a p1301-BS-RNAi vector using lycB from Dunaliella salina as the interference sequence with kanamycin and atrazine resistance marker, and then transformed it into H. pluvialis by electroporation. Sixteen independent transgenic lines were obtained after resistance selection, genome PCR, and RT-PCR analyses. Seven well-grown lines were selected to determine the contents of carotenoids by HPLC analysis after inducing by high light. The lycopene content in these lines was increased by 99.4% while the β-carotene content was decreased by 48.4%, indicating that the interference by heterogenous lycB could inhibit the conversion of lycopene into β-carotene. The amount of increase in lycopene was only 5% of the amount of decrease in β-carotene, indicating that 95% of the decreased β-carotene was converted into other metabolites. Therefore, in order to largely increase the lycopene content in H. pluvialis, it is necessary to coordinatively regulate other metabolic pathways.

  13. Metabolomic and network analysis of astaxanthin-producing Haematococcus pluvialis under various stress conditions.

    PubMed

    Su, Yingxue; Wang, Jiangxin; Shi, Mengliang; Niu, Xiangfeng; Yu, Xinheng; Gao, Lianju; Zhang, Xiaoqing; Chen, Lei; Zhang, Weiwen

    2014-10-01

    Various combinations of acetate (Ac), Fe(2+) and high light (HL) stress conditions were evaluated to maximize astaxanthin accumulation and biomass production in Haematococcus pluvialis, and then GC-MS and LC-MS based metabolomics were applied to determine molecular mechanisms responsible for enhancing astaxanthin accumulation under the stress conditions. With the optimized analytical protocols, the GC-MS and LC-MS analyses allowed identification of 93 stable and 24 unstable intracellular metabolites from H. pluvialis, respectively. In addition, a metabolic network was constructed based on GC-MS metabolomic datasets using a weighted correlation network analysis (WGCNA) approach. The network analysis uncovered 2, 1 and 1 distinguished metabolic modules highly associated with HL, Fe(2+) & HL, and Ac & Fe(2+) & HL conditions, respectively. Finally, LC-MS analysis found that AKG, Glu and R5P may be metabolites associated with the Fe(2+) & HL condition. The study provided the first metabolomic view of cell growth and astaxanthin accumulation in H. pluvialis.

  14. UV-C mediated rapidcarotenoid induction and settling performance of Dunaliellasalina and Haematococcus pluvialis.

    PubMed

    Sharma, Kalpesh K; Ahmed, Faruq; Schenk, Peer M; Li, Yan

    2015-10-01

    Microalgae are primary producers of organic pigments carotenoids in aquatic environments. However, commercial-scale microalgae application for high value carotenoids production is rarely economical due to the cost-effectiveness of carotenoid induction and microalgal harvesting process. Here, we present a novel approach, using a small dose of externally applied UV-C radiation, to rapidly induce unsaturated fatty acids and carotenoid biosynthesis in Dunaliella salina and Haematococcus pluvialis, and also to significantly promote their swimming cells settling for primary dewatering. The amount of total carotenoids and β-carotenoid were doubled in 24 h on D. salina upon 50 mJ/cm(2) of UV-C radiation, whereas the astaxanthin yield of H. pluvialis was increased five times in 48 h at 30 mJ/cm(2) . Meanwhile, 95% of algal cells of D. salina and H. pluvialis settled in 15 h and 2 h, respectively. This novel technique represents a convenient, time-saving and cost-effective method for commercial microalgal carotenoids production.

  15. Enhancement of astaxanthin production from Haematococcus pluvialis mutants by three-stage mutagenesis breeding.

    PubMed

    Wang, Ni; Guan, Bin; Kong, Qing; Sun, Han; Geng, Zhaoyan; Duan, Liangfei

    2016-10-20

    Haematococcus pluvialis was modified for higher astaxanthin production compatible with the superiorities of high biomass and high activity by three-stage mutagenesis breeding. UV irradiation mutants named UV11-4 made an increase on cell dry weight, but showed a longer growth circle than the wild type. On the basis of UV mutants, ethyl methane sulphonate (EMS) mutants E2-5 cut down the latent phase, brought forward and extended the logarithmic phase. The inhibitor diphenylamine (DPA) was employed to screen high-yield astaxanthin producer by the color change of colonies from green to red on solid medium. Via the contravariant cultivation, proliferation and transformation, the mutant DPA12-2 possessed an 1.7-fold astaxanthin production compared to the wild type, reaching 47.21±3.30mg/g dry cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. A new flagellated dispersion stage in Paraphysoderma sedebokerense, a pathogen of Haematococcus pluvialis.

    PubMed

    Strittmatter, Martina; Guerra, Tiago; Silva, Joana; Gachon, Claire M M

    The blastocladialean fungus Paraphysoderma sedebokerense Boussiba, Zarka and James is a devastating pathogen of the commercially valuable green microalga Haematococcus pluvialis, a natural source of the carotenoid pigment astaxanthin. First identified in commercial Haematococcus cultivation facilities, P. sedebokerense is hypothesised to have a complex life cycle that switches between a vegetative and a resting phase depending on favourable or unfavourable growth conditions. Rather unusually for blastocladialean fungi, P. sedebokerense was described as lacking flagellated zoospores and only propagating via aplanosporic amoeboid cells. However, during repeated microscopic observation of P. sedebokerense cultivated in optimal conditions, we detected fast-swimming, transiently uniflagellated zoospores which rapidly transform into infectious amoeboid swarmers, the existence of which suggests a closer than previously thought relatedness of P. sedebokerense to its sister genera Physoderma and Urophlyctis. Additionally, we found some morphological and physiological differences between amoeboid swarmers and discuss hypotheses about their significance. These amoeboid and flagellated propagules are key to the dissemination of P. sedebokerense and are probably also the life stages most vulnerable to adverse environmental conditions. They are therefore a prime target for the development of disease management protocols in industrial cultivation facilities, a goal which requires a detailed understanding of their physiology.

  17. Determination of astaxanthin in Haematococcus pluvialis by first-order derivative spectrophotometry.

    PubMed

    Liu, Xiao Juan; Juan, Liu Xiao; Wu, Ying Hua; Hua, Wu Ying; Zhao, Li Chao; Chao, Zhao Li; Xiao, Su Yao; Yao, Xiao Su; Zhou, Ai Mei; Mei, Zhou Ai; Liu, Xin; Xin, Liu

    2011-01-01

    A highly selective, convenient, and precise method, first-order derivative spectrophotometry, was applied for the determination of astaxanthin in Haematococcus pluvialis. Ethyl acetate and ethanol (1:1, v/v) were found to be the best extraction solvent tested due to their high efficiency and low toxicity compared with nine other organic solvents. Astaxanthin coexisting with chlorophyll and beta-carotene was analyzed by first-order derivative spectrophotometry in order to optimize the conditions for the determination of astaxanthin. The results show that when detected at 432 nm, the interfering substances could be eliminated. The dynamic linear range was 2.0-8.0 microg/mL, with a correlation coefficient of 0.9916. The detection threshold was 0.41 microg/mL. The RSD for the determination of astaxanthin was in the range of 0.01-0.06%; the results of recovery test were 98.1-108.0%. The statistical analysis between first-order derivative spectrophotometry and HPLC by T-testing did not exceed their critical values, revealing no significant differences between these two methods. It was proved that first-order derivative spectrophotometry is a rapid and convenient method for the determination of astaxanthin in H. pluvialis that can eliminate the negative effect resulting from the coexistence of astaxanthin with chlorophyll and beta-carotene.

  18. Expression of fatty acid synthesis genes and fatty acid accumulation in haematococcus pluvialis under different stressors

    PubMed Central

    2012-01-01

    Background Biofuel has been the focus of intensive global research over the past few years. The development of 4th generation biofuel production (algae-to-biofuels) based on metabolic engineering of algae is still in its infancy, one of the main barriers is our lacking of understanding of microalgal growth, metabolism and biofuel production. Although fatty acid (FA) biosynthesis pathway genes have been all cloned and biosynthesis pathway was built up in some higher plants, the molecular mechanism for its regulation in microalgae is far away from elucidation. Results We cloned main key genes for FA biosynthesis in Haematococcus pluvialis, a green microalga as a potential biodiesel feedstock, and investigated the correlations between their expression alternation and FA composition and content detected by GC-MS under different stress treatments, such as nitrogen depletion, salinity, high or low temperature. Our results showed that high temperature, high salinity, and nitrogen depletion treatments played significant roles in promoting microalgal FA synthesis, while FA qualities were not changed much. Correlation analysis showed that acyl carrier protein (ACP), 3-ketoacyl-ACP-synthase (KAS), and acyl-ACP thioesterase (FATA) gene expression had significant correlations with monounsaturated FA (MUFA) synthesis and polyunsaturated FA (PUFA) synthesis. Conclusions We proposed that ACP, KAS, and FATA in H. pluvialis may play an important role in FA synthesis and may be rate limiting genes, which probably could be modified for the further study of metabolic engineering to improve microalgal biofuel quality and production. PMID:22448811

  19. Expression of fatty acid synthesis genes and fatty acid accumulation in haematococcus pluvialis under different stressors.

    PubMed

    Lei, Anping; Chen, Huan; Shen, Guoming; Hu, Zhangli; Chen, Lei; Wang, Jiangxin

    2012-03-26

    Biofuel has been the focus of intensive global research over the past few years. The development of 4th generation biofuel production (algae-to-biofuels) based on metabolic engineering of algae is still in its infancy, one of the main barriers is our lacking of understanding of microalgal growth, metabolism and biofuel production. Although fatty acid (FA) biosynthesis pathway genes have been all cloned and biosynthesis pathway was built up in some higher plants, the molecular mechanism for its regulation in microalgae is far away from elucidation. We cloned main key genes for FA biosynthesis in Haematococcus pluvialis, a green microalga as a potential biodiesel feedstock, and investigated the correlations between their expression alternation and FA composition and content detected by GC-MS under different stress treatments, such as nitrogen depletion, salinity, high or low temperature. Our results showed that high temperature, high salinity, and nitrogen depletion treatments played significant roles in promoting microalgal FA synthesis, while FA qualities were not changed much. Correlation analysis showed that acyl carrier protein (ACP), 3-ketoacyl-ACP-synthase (KAS), and acyl-ACP thioesterase (FATA) gene expression had significant correlations with monounsaturated FA (MUFA) synthesis and polyunsaturated FA (PUFA) synthesis. We proposed that ACP, KAS, and FATA in H. pluvialis may play an important role in FA synthesis and may be rate limiting genes, which probably could be modified for the further study of metabolic engineering to improve microalgal biofuel quality and production.

  20. Ethanol induced astaxanthin accumulation and transcriptional expression of carotenogenic genes in Haematococcus pluvialis.

    PubMed

    Wen, Zewen; Liu, Zhiyong; Hou, Yuyong; Liu, Chenfeng; Gao, Feng; Zheng, Yubin; Chen, Fangjian

    2015-10-01

    Haematococcus pluvialis is one of the most promising natural sources of astaxanthin. However, inducing the accumulation process has become one of the primary obstacles in astaxanthin production. In this study, the effect of ethanol on astaxanthin accumulation was investigated. The results demonstrated that astaxanthin accumulation occurred with ethanol addition even under low-light conditions. The astaxanthin productivity could reach 11.26 mg L(-1) d(-1) at 3% (v/v) ethanol, which was 2.03 times of that of the control. The transcriptional expression patterns of eight carotenogenic genes were evaluated using real-time PCR. The results showed that ethanol greatly enhanced transcription of the isopentenyl diphosphate (IPP) isomerase genes (ipi-1 and ipi-2), which were responsible for isomerization reaction of IPP and dimethylallyl diphosphate (DMAPP). This finding suggests that ethanol induced astaxanthin biosynthesis was up-regulated mainly by ipi-1 and ipi-2 at transcriptional level, promoting isoprenoid synthesis and substrate supply to carotenoid formation. Thus ethanol has the potential to be used as an effective reagent to induce astaxanthin accumulation in H. pluvialis. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Four Different Methods Comparison for Extraction of Astaxanthin from Green Alga Haematococcus pluvialis

    PubMed Central

    Dong, Shengzhao; Huang, Yi; Zhang, Rui; Wang, Shihui; Liu, Yun

    2014-01-01

    Haematococcus pluvialis is one of the potent organisms for production of astaxanthin. Up to now, no efficient method has been achieved due to its thick cell wall hindering solvent extraction of astaxanthin. In this study, four different methods, hydrochloric acid pretreatment followed by acetone extraction (HCl-ACE), hexane/isopropanol (6 : 4, v/v) mixture solvents extraction (HEX-IPA), methanol extraction followed by acetone extraction (MET-ACE, 2-step extraction), and soy-oil extraction, were intensively evaluated for extraction of astaxanthin from H. pluvialis. Results showed that HCl-ACE method could obtain the highest oil yield (33.3 ± 1.1%) and astaxanthin content (19.8 ± 1.1%). Quantitative NMR analysis provided the fatty acid chain profiles of total lipid extracts. In all cases, oleyl chains were predominant, and high amounts of polyunsaturated fatty acid chains were observed and the major fatty acid components were oleic acid (13–35%), linoleic acid (37–43%), linolenic acid (20–31%), and total saturated acid (17–28%). DPPH radical scavenging activity of extract obtained by HCl-ACE was 73.2 ± 1.0%, which is the highest amongst the four methods. The reducing power of extract obtained by four extraction methods was also examined. It was concluded that the proposed extraction method of HCl-ACE in this work allowed efficient astaxanthin extractability with high antioxidant properties. PMID:24574909

  2. Haematococcus pluvialis soluble proteins: Extraction, characterization, concentration/fractionation and emulsifying properties.

    PubMed

    Ba, Fatou; Ursu, Alina Violeta; Laroche, Céline; Djelveh, Gholamreza

    2016-01-01

    A water-soluble matrix was extracted from green vegetative Haematococcus pluvialis through high-pressure cell disruption either at native pH (5.7) or with pH shifting to neutral (7). The resulting supernatant is mainly composed of carbohydrates and proteins, with the highest yield of proteins obtained at neutral pH (73±2% of total biomass proteins). The key emulsification properties of the proteins isolated in neutral supernatant (emulsification capacity (EC): 534±41mLoilg(-1) protein, emulsification stability (ES): 94±3% and emulsification activity index (EAI): 80±1m(2)g(-1)) were comparable to the native supernatant values (EC: 589±21mLoilg(-1) protein, ES: 84±3% and EAI: 75±1m(2)g(-1)). Confronted to sodium caseinate (EC: 664±30mLoilg(-1) protein, ES: 63±4%, and EAI: 56±4m(2)g(-1)) these results highlighted the strong potential of proteins isolated from H. pluvialis as emulsifier agent. Moreover, experiments have shown that the stability of emulsions obtained from supernatants is due to the proteins rather than the carbohydrates.

  3. Variation in Rubisco and other photosynthetic parameters in the life cycle of Haematococcus pluvialis

    NASA Astrophysics Data System (ADS)

    Chen, Zhangfan; Wang, Guangce; Niu, Jianfeng

    2012-01-01

    Cells of Haematococcus pluvialis Flot. et Will were collected in four different growth phases. We quantified the initial and total enzyme activity of ribulose-1,5-bisphosphate carboxylase (Rubisco) in crude extracts, and the relative expression of large-subunit ribulose-1,5-bisphosphate caboxylase / oxygenase ( rbcL) mRNA. We measured the ratio of photosynthetic rate to respiration rate (P/R), maximal effective quantum yield of photosystem II ( F v/ F m), electron transport rate (ETR), actual photochemical efficiency of PSII in the light (PSII), and non-photochemical quenching (NPQ). Green vegetative cells were found to be in the most active state, with a relatively higher P/R ratio. These cells also displayed the lowest NPQ and the highest F v/ F m, ETR, and PSII, indicating the most effective PSII. However, both Rubisco activity and rbcL mRNA expression were the lowest measured. In orange resting cysts with relatively lower P/R and NPQ, Rubisco activity and rbcL expression reached a peak, while F v/ F m, ETR, and ΦPSII were the lowest measured. Taking into account the methods of astaxanthin induction used in industry, we suggest that Rubisco may participate in astaxanthin accumulation in H. pluvialis. A continuous and sufficient supply of a carbon source such as CO2 may therefore aid the large scale production of astaxanthin.

  4. A Microreactor System for Cultivation of Haematococcus pluvialis and Astaxanthin Production.

    PubMed

    Kwak, Ho Seok; Kim, Jaoon Young Hwan; Sim, Sang Jun

    2015-02-01

    Development of efficient culture and monitoring system for cell growth and production of useful materials is required for practical utilization of microalgae. In the present study, we developed a PDMS-based microreactor system for efficient, rapid culture of microalgae and monitoring of cell growth, carotenoid content under diverse culture conditions. Due to advantages of PDMS, we optimized culture conditions (light intensity, pH, nitrate depletion, carbon dioxide concentration) for improving growth rate and astaxanthin productivity in considerably less time compared to conventional culture methods using flask or well plate. In addition, we found that there was a strong linear correlation between fluorescence intensity of astaxanthin stained by Nile red and the astaxanthin content, which can be utilized as a high-throughput screening tool in microfluidic systems. In this study, the growth rate of vegetative Haematococcus pluvialis was improved by 60% in microfluidic chamber than in flask and astaxanthin was produced up to 362 mg/L under the optimal conditions (300 µmol photon/m2/s of light, 7% CO2 (v/v), and pH 7.0) using designed microfluidic devices. This result shows that microfluidic system can provide effective means to address development of microalgal strains including H. pluvialis and bioprocess.

  5. Regenerative Astaxanthin Extraction from a Single Microalgal (Haematococcus pluvialis) Cell Using a Gold Nano-Scalpel.

    PubMed

    Praveenkumar, Ramasamy; Gwak, Raekeun; Kang, Mijeong; Shim, Tae Soup; Cho, Soojeong; Lee, Jiye; Oh, You-Kwan; Lee, Kyubock; Kim, Bongsoo

    2015-10-14

    Milking of microalgae, the process of reusing the biomass for continuous production of target compounds, can strikingly overcome the time and cost constraints associated with biorefinery. This process can significantly improve production efficiency of highly valuable chemicals, for example, astaxanthin (AXT) from Haematococcus pluvialis. Detailed understanding of the biological process of cell survival and AXT reaccumulation after extraction would be of great help for successful milking. Here we report extraction of AXT from a single cell of H. pluvialis through incision of the cell wall by a gold nanoscalpel (Au-NS), which allows single-cell analysis of wound healing and reaccumulation of AXT. Interestingly, upon the Au-NS incision, the cell could reaccumulate AXT at a rate two times faster than the control cells. Efficient extraction as well as minimal cellular damage, keeping cells alive, could be achieved with the optimized shape and dimensions of Au-NS: a well-defined sharp tip, thickness under 300 nm, and 1-3 μm of width. The demonstration of regenerative extraction of AXT at a single cell level hints toward the potential of a milking process for continuous recovery of target compounds from microalgae while keeping the cells alive.

  6. Four different methods comparison for extraction of astaxanthin from green alga Haematococcus pluvialis.

    PubMed

    Dong, Shengzhao; Huang, Yi; Zhang, Rui; Wang, Shihui; Liu, Yun

    2014-01-01

    Haematococcus pluvialis is one of the potent organisms for production of astaxanthin. Up to now, no efficient method has been achieved due to its thick cell wall hindering solvent extraction of astaxanthin. In this study, four different methods, hydrochloric acid pretreatment followed by acetone extraction (HCl-ACE), hexane/isopropanol (6:4, v/v) mixture solvents extraction (HEX-IPA), methanol extraction followed by acetone extraction (MET-ACE, 2-step extraction), and soy-oil extraction, were intensively evaluated for extraction of astaxanthin from H. pluvialis. Results showed that HCl-ACE method could obtain the highest oil yield (33.3±1.1%) and astaxanthin content (19.8±1.1%). Quantitative NMR analysis provided the fatty acid chain profiles of total lipid extracts. In all cases, oleyl chains were predominant, and high amounts of polyunsaturated fatty acid chains were observed and the major fatty acid components were oleic acid (13-35%), linoleic acid (37-43%), linolenic acid (20-31%), and total saturated acid (17-28%). DPPH radical scavenging activity of extract obtained by HCl-ACE was 73.2±1.0%, which is the highest amongst the four methods. The reducing power of extract obtained by four extraction methods was also examined. It was concluded that the proposed extraction method of HCl-ACE in this work allowed efficient astaxanthin extractability with high antioxidant properties.

  7. Nondestructive monitoring of carotenogenesis in Haematococcus pluvialis via whole-cell optical density spectra.

    PubMed

    Solovchenko, Alexei; Aflalo, Claude; Lukyanov, Alexander; Boussiba, Sammy

    2013-05-01

    We investigated the feasibility of rapid, nondestructive assay of carotenoid-to-chlorophyll (Car/Chl) ratio and total carotenoids (Car) in cell suspensions of the carotenogenic chlorophyte Haematococcus pluvialis Flotow under stressful conditions. Whole-cell spectra are characterized by variable nonlinear contributions of Car and chlorophylls (Chl), with a strong influence of Car packaging and sieve effect inherent to stressed H. pluvialis cells. Nevertheless, nondestructive assay of Car/Chl in the range of 0.55-31.2 (Car content up to 188 mg L(-1); 5.4 % of the cell dry weight) turned to be achievable with a simple spectrophotometer lacking an integrating sphere upon deposition of the cells on glass fiber filters. The scattering-corrected optical density (OD) in the blue-green region of the whole-cell spectrum, normalized to that in the red maximum of Chl absorption (OD500/OD678), was tightly related (r (2) = 0.96) with the Car/Chl ratio found in extracts. Some features such as the amplitude and position of the minimum of the normalized first-derivative OD whole-cell spectra also exhibited a strong (r (2) > 0.90) nonlinear correlation with Car/Chl. These spectral indices were also tightly related with Car, but the slope of the relationship varied with the stressor intensity. The importance of calibration over the widest possible range of pigment contents and a correct choice of biomass load per filter are emphasized. The advantages and limitations of nondestructive monitoring of carotenogenesis in H. pluvialis are discussed in view of its possible application in optical sensors for laboratory cultivation and mass production systems of the algae.

  8. Determination of the time transferring cells for astaxanthin production considering two-stage process of Haematococcus pluvialis cultivation.

    PubMed

    Choi, Yoon-E; Yun, Yeoung-Sang; Park, Jong Moon; Yang, Ji-Won

    2011-12-01

    The two-stage culture system consisting of green vegetative growth and reddish inductive production stages has been widely accepted for the production of astaxanthin using Haematococcus pluvialis. However, little has been known about the appropriate cellular phase of H. pluvialis for transferring into the astaxanthin inductive conditions. In this study, we determined the optimal growth phase of H. pluvialis for transferring into the second production stage. Astaxanthin productivities were correlated with growth phases, as senescent green phases could increase more than 10-fold greater than juvenile green phases. Our results clearly demonstrated the appropriateness of the senescent vegetable cells for transferring into the production stage, due to the increased capacity to accumulate astaxanthin.

  9. Optimizing gas transfer to improve growth rate of Haematococcus pluvialis in a raceway pond with chute and oscillating baffles.

    PubMed

    Yang, Zongbo; Cheng, Jun; Li, Ke; Zhou, Junhu; Cen, Kefa

    2016-08-01

    Up-down chute and oscillating (UCO) baffles were used to generate vortex and oscillating flow field to improve growth rate of Haematococcus pluvialis in a raceway pond. Effects of gas flow rate, solution velocity, and solution depth on solution mass transfer coefficient and mixing time were evaluated using online pH and dissolved oxygen probes. Mass transfer coefficient increased by 1.3 times and mixing time decreased by 33% when UCO baffles were used in the H. pluvialis solution, resulting in an 18% increase in biomass yield with 2% CO2. The H. pluvialis biomass yield further increased to 1.5g/L, and astaxanthin composition accumulated to 29.7mg/L under relatively higher light intensity and salinity.

  10. Regulation of astaxanthin and its intermediates through cloning and genetic transformation of β-carotene ketolase in Haematococcus pluvialis.

    PubMed

    Kathiresan, S; Chandrashekar, Arun; Ravishankar, G A; Sarada, R

    2015-02-20

    Astaxanthin, a high-value ketocarotenoid used in the pharmaceutical and nutraceutical industries is mainly produced from green alga, Haematococcus pluvialis. It is biosynthesized by the action of key enzyme, β-carotene ketolase (BKT) on β-carotene through intermediates echinenone and canthaxanthin. In this study, the β-carotene ketolase (bkt) gene was isolated from H. pluvialis and cloned in a vector pRT100 and further mobilized to a binary vector pCAMBIA 1304. The T-DNA of pCAMBIA 1304, which consists of cloned bkt, was successfully transformed to H. pluvialis through Agrobacterium mediation. The cloning and transformation of bkt in H. pluvialis was confirmed by Southern blotting and also by PCR analysis. Total carotenoids and astaxanthin content in the transformed cells were found to be 2-3-fold higher, while the intermediates like echinenone and canthaxanthin were found to be 8-10-fold higher than in the control cells. The expression level of carotenogenic genes like phytoene synthase (psy), phytoene desaturase (pds), lycopene cyclase (lcy), bkt, and β-carotene hydroxylase (bkh) were found to be higher in transformed cells compared to the non-transformed (NT) H. pluvialis.

  11. A Novel Organic Electrochemical Transistor-Based Platform for Monitoring the Senescent Green Vegetative Phase of Haematococcus pluvialis Cells.

    PubMed

    Wei, Weiwei; Xiao, Kang; Tao, Ming; Nie, Lifu; Liu, Dan; Ke, Shanming; Zeng, Xierong; Hu, Zhangli; Lin, Peng; Zhang, Yu

    2017-08-31

    The freshwater unicellular microalga Haematococcus pluvialis (H. pluvialis) has gained increasing attention because of its high-value metabolite astaxanthin, a super anti-oxidant. For the maximum astaxanthin production, a key problem is how to determine the senescent green vegetative phase of H. pluvialis cells to apply the astaxanthin production inducers. The conventional methods are time-consuming and laborious. In this study, a novel platform based on organic electrochemical transistor (OECT) was produced. A significant channel current change of OECTs caused by settled H. pluvialis cells on the poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) film was recorded commencing from 75 min and a stationary stage was achieved at 120 min after the combined treatment of blue light irradiation and sodium bicarbonate solution additives, which indicate the onset and maturation of the senescent green vegetative phase, respectively. Therefore, the appropriate time point (120 min after sample loading) to apply astaxanthin production inducers was determined by as-fabricated OECTs. This work may assist to develop a real-time biosensor to indicate the appropriate time to apply inducers for a maximum astaxanthin production of H. pluvialis cells.

  12. Strain H2-419-4 of Haematococcus pluvialis induced by ethyl methanesulphonate and ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Sun, Yanhong; Liu, Jianguo; Zhang, Xiaoli; Lin, Wei

    2008-05-01

    Two strains H2-410 and H2-419 were obtained from the chemically mutated survivors of wild Haematococcus pluvialis 2 by using ethyl methanesulphonate (EMS). Strains H2-410 and H2-419 showed a fast cell growth with 13% and 20% increase in biomass compared to wild type, respectively. Then H2-419-4, a fast cell growth and high astaxanthin accumulation strain, was obtained by exposing the strain H2-419 to ultraviolet radiation (UV) further. The total biomass, the astaxanthin content per cell, astaxanthin production of H2-419-4 showed 68%, 28%, and 120% increase compared to wild H. pluvialis 2, respectively. HPLC (High Performance Liquid Chromatography) data showed also an obvious proportional variation of different carotenoid compositions in the extracts of H2-419-4 and the wild type, although no peak of carotenoids appeared or disappeared. Therefore, the main compositions in strain H2-419-4, like its wild one, were free of astaxanthin, monoester, and diester of astaxanthin. The asexual reproduction in survivors after exposed to UV was not synchronous, and different from the normal synchronous asexual reproduction as the mother cells were motile instead of non-motile. Interestingly, some survivors from UV irradiation produced many mini-spores (or gamete?), the spores moved away from the mother cell gradually 4 or 5 days later. This is quite similar to sexual reproduction described by Elliot in 1934. However, whether this was sexual reproduction remains questionable, as no mating process has been observed.

  13. Effects of iron electrovalence and species on growth and astaxanthin production of Haematococcus pluvialis

    NASA Astrophysics Data System (ADS)

    Cai, Minggang; Li, Zhe; Qi, Anxiang

    2009-05-01

    To increase the cell concentration and the accumulation of astaxanthin in the cultivation of Haematococcus pluvialis, effects of different iron electrovalencies (Fe2+-EDTA and Fe3+-EDTA) and species (Fe-EDTA, Fe(OH){x/32x} and FeC6H5O7) addition on cell growth and accumulation of astaxanthin were studied. Results show that different iron electrovalencies have various effects on cell growth and astaxanthin accumulation of H. pluvialis. Compared with Fe3+-EDTA, Fe2+-EDTA stimulate more effectively the formation of astaxanthin. The maximum astaxanthin content (30.70 mg/g biomass cell) was obtained under conditions of 18 μmol/L Fe2+-EDTA, despite the lower cell density (2.3×105 cell/ml) in such condition. Fe3+-EDTA is more effective than Fe2+-EDTA in improving the cell growth. Especially, the maximal steady-state cell density, 2.9×105 cell/ml was obtained at 18 μmol/L Fe3+-EDTA addition. On the other hand, all the various species of iron (EDTA-Fe, Fe(OH){x/32x}, FeC6H5O7) are capable to improve the growth of the algae and astaxanthin production. Among the three iron species, FeC6H5O7 performed the best. Under the condition of a higher concentration (36 μmol/L) of FeC6H5O7, the cell density and astaxanthin production is 2 and 7 times higher than those of iron-limited group, respectively. The present study demonstrates that the effects of the stimulation with different iron species increased in the order of FeC6H5O7, Fe(OH){x/32x} and EDTA-Fe.

  14. Dynamic changes of inorganic nitrogen and astaxanthin accumulation in Haematococcus pluvialis

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Guo; Yin, Ming-Yan; Zhang, Jing-Pu; Liu, Wei; Meng, Zhao-Cai

    2002-12-01

    This study on dynamic changes of culture color, astaxanthin and chlorophylls, inorganic N including N-NO{3/-}, N-NO{2/-} and N-NH{4/+} in batch culture of Haematococcus pluvialis exposed to different additive nitrate concentration showed (1) ast/chl ratio was over 0.8 for brown and red algae, but was usually less than 0.5 for green and yellow algae; (2) N-NO{3/-}, in general, was unstable and decreased, except for a small unexpected increase in nitrate enriched treatment groups; (3) measurable amounts of N-NO{2/-}, and N-NH{4/+} were observed respectively with three change modes although no external nitrite and ammonia were added into the culture; (4) a non-linear correlation between ast/chl ratio (or color) changes and the levels of N-NO{3/-}, N-NO{2/-}, N-NH{4/+} in H. pluvialis culture; (5) up and down variation of the ast/chl ratio occurred simultaneously with a perceptible color change from yellow to brown (or red) when N-NO{3/-}, N-NO{2/-} and N-NH{4/+} fluctuated around 30, 5, 5, μmol/L respectively; (6) existence of three dynamic modes of N-NO{3/-}, N-NO{2/-} and N-NH{4/+} changes, obviously associated with initial external nitrate; (7) the key level of total inorganic N concentration regulating the above physiological changes during indoor cultivation was about 50 μmol/L; and (8) 0.5 10 mmol/L of nitrate was theoretically conducive to cell growth in batch culture.

  15. Antioxidative capacity and enzyme activity in Haematococcus pluvialis cells exposed to superoxide free radicals

    NASA Astrophysics Data System (ADS)

    Liu, Jianguo; Zhang, Xiaoli; Sun, Yanhong; Lin, Wei

    2010-01-01

    The antioxidative capacity of astaxanthin and enzyme activity of reactive oxygen eliminating enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were studied in three cell types of Haematococcus pluvialis exposed to high concentrations of a superoxide anion radical (O{2/-}). The results show that defensive enzymes and astaxanthin-related mechanisms were both active in H. pluvialis during exposure to reactive oxygen species (ROS) such as O{2/-}. Astaxanthin reacted with ROS much faster than did the protective enzymes, and had the strongest antioxidative capacity to protect against lipid peroxidation. The defensive mechanisms varied significantly between the three cell types and were related to the level of astaxanthin that had accumulated in those cells. Astaxanthin-enriched red cells had the strongest antioxidative capacity, followed by brown cells, and astaxanthin-deficient green cells. Although there was no significant increase in expression of protective enzymes, the malondialdehyde (MDA) content in red cells was sustained at a low level because of the antioxidative effect of astaxanthin, which quenched O{2/-} before the protective enzymes could act. In green cells, astaxanthin is very low or absent; therefore, scavenging of ROS is inevitably reliant on antioxidative enzymes. Accordingly, in green cells, these enzymes play the leading role in scavenging ROS, and the expression of these enzymes is rapidly increased to reduce excessive ROS. However, because ROS were constantly increased in this study, the enhance enzyme activity in the green cells was not able to repair the ROS damage, leading to elevated MDA content. Of the four defensive enzymes measured in astaxanthin-deficient green cells, SOD eliminates O{2/-}, POD eliminates H2O2, which is a by-product of SOD activity, and APX and CAT are then initiated to scavenge excessive ROS.

  16. Phylogenetic Position and Molecular Chronology of a Colonial Green Flagellate, Stephanosphaera pluvialis (Volvocales, Chlorophyceae), among Unicellular Algae.

    PubMed

    Munakata, Hidehito; Nakada, Takashi; Nakahigashi, Kenji; Nozaki, Hisayoshi; Tomita, Masaru

    2016-05-01

    The genus Balticola comprises a group of unicellular green flagellate algae and is composed of four species formerly classified in the genus Haematococcus. Balticola is closely related to a colonial green flagellate, Stephanosphaera pluvialis. Although the phylogeny among these genera was previously investigated based on two nuclear gene sequences, the phylogenetic sister of S. pluvialis has yet to be determined. In the present study, the species diversity of Balticola and Stephanosphaera was investigated using 18S rRNA gene sequences, and phylogenetic analyses of combined nuclear and chloroplast gene sequences were performed to understand the evolutionary origin of coloniality in Stephanosphaera. The divergence times of four colonial volvocalean flagellates from their respective unicellular sisters were also estimated. Six Balticola genotypes and a single Stephanosphaera genotype were recognized, and one Balticola genotype was resolved as the sister of S. pluvialis, showing that Balticola is a nonmonophyletic genus. The divergence time of Stephanosphaera from its nearest Balticola relative was estimated to be 4-63 million years ago, and these genera represent the most recently diverged pair of unicellular and colonial flagellates among the Volvocales.

  17. Hydrolysis kinetics of astaxanthin esters and stability of astaxanthin of Haematococcus pluvialis during saponification.

    PubMed

    Yuan, J P; Chen, F

    1999-01-01

    The reaction kinetics for the hydrolysis of astaxanthin esters and the degradation of astaxanthin during saponification of the pigment extract from the microalga Haematococcus pluvialis were investigated. Different concentrations of sodium hydroxide in methanol were used for the saponification under nitrogen in darkness at ambient temperature (22 degrees C) followed by the analysis of astaxanthins and other carotenoids using an HPLC method. The concentration of methanolic NaOH solution was important for promoting the hydrolysis of astaxanthin esters and minimizing the degradation of astaxanthin during saponification. With a higher concentration of methanolic NaOH solution, the reaction rate of hydrolysis was high, but the degradation of astaxanthin occurred significantly. The rate constants of the hydrolysis reaction (first order) of astaxanthin esters and the degradation reaction (zero-order) of astaxanthin were directly proportional to the concentration of sodium hydroxide in the saponified solution. Although the concentration of sodium hydroxide in the saponified solution was 0.018 M, complete hydrolysis of astaxanthin esters was achieved in 6 h for different concentrations (10-100 mg/L) of pigment extracts. Results also indicated that a higher temperature should be avoided to minimize the degradation of astaxanthin. In addition, during saponification, no loss of lutein, beta-carotene, and canthaxanthin was found.

  18. Transcriptome sequencing and metabolic pathways of astaxanthin accumulated in Haematococcus pluvialis mutant under 15% CO2.

    PubMed

    Cheng, Jun; Li, Ke; Zhu, Yanxia; Yang, Weijuan; Zhou, Junhu; Cen, Kefa

    2017-03-01

    Transcriptome sequencing and annotation was performed on Haematococcus pluvialis mutant red cells induced with high light under 15% CO2 to demonstrate why astaxanthin yield of the mutant was 1.7 times higher than that of a wild strain. It was found that 56% of 1947 differentially expressed genes were upregulated in mutant cells. Most significant differences were found in unigenes related to photosynthesis, carotenoid biosynthesis and fatty acid biosynthesis pathways. The pyruvate kinase increased by 3.5-fold in mutant cells. Thus, more pyruvate, which was beneficial to carotenoids and fatty acid biosynthesis, was generated. Phytoene synthase, zeta-carotene desaturase, lycopene beta-cyclase involved in β-carotene biosynthesis in mutant cells were upregulated by 10.4-, 4.4-, and 5.8-fold, respectively. Beta-carotene 3-hydroxylase catalyzing conversion of β-carotene into astaxanthin was upregulated by 18.4-fold. The fatty acid biosynthesis was promoted because of the upregulation of acetyl-CoA synthetase and acetyl-CoA carboxylase, thus increasing astaxanthin esterification and accumulation in mutant cells.

  19. Effects of spray-drying and storage on astaxanthin content of Haematococcus pluvialis biomass.

    PubMed

    Raposo, Maria Filomena J; Morais, Alcina M M B; Morais, Rui M S C

    2012-03-01

    The main objective of this study was to evaluate the stability of astaxanthin after drying and storage at different conditions during a 9-week period. Recovery of astaxanthin was evaluated by extracting pigments from the dried powders and analysing extracts by HPLC. The powders obtained were stored under different conditions of temperature and oxygen level and the effects on the degradation of astaxanthin were examined. Under the experimental conditions conducted in this study, the drying temperature that yielded the highest content of astaxanthin was 220°C, as the inlet, and 120°C, as the outlet temperature of the drying chamber. The best results were obtained for biomass dried at 180/110°C and stored at -21°C under nitrogen, with astaxanthin degradation lower than 10% after 9 weeks of storage. A reasonable preservation of astaxanthin can be achieved by conditions 180/80°C, -21°C nitrogen, 180/110°C, 21°C nitrogen, and 220/80°C, 21°C vacuum: the ratio of astaxanthin degradation is equal or inferior to 40%. In order to prevent astaxanthin degradation of Haematococcus pluvialis biomass, it is recommended the storage of the spray dried carotenized cells (180/110ºC) under nitrogen and -21°C.

  20. Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity.

    PubMed

    Régnier, Philippe; Bastias, Jorge; Rodriguez-Ruiz, Violeta; Caballero-Casero, Noelia; Caballo, Carmen; Sicilia, Dolores; Fuentes, Axelle; Maire, Murielle; Crepin, Michel; Letourneur, Didier; Gueguen, Virginie; Rubio, Soledad; Pavon-Djavid, Graciela

    2015-05-07

    Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases.

  1. Effect of various stress-regulatory factors on biomass and lipid production in microalga Haematococcus pluvialis.

    PubMed

    Saha, Sushanta Kumar; McHugh, Edward; Hayes, Jeremiah; Moane, Siobhan; Walsh, Daniel; Murray, Patrick

    2013-01-01

    To maximize the biomass and lipid production for applications in food or biofuel feedstock, nine stress conditions were tested considering N and/or P limitations, light intensity & quality, for Haematococcus pluvialis SCCAP K-0084 cultivation. Photosynthetically active radiation (PAR), warm white light emitting diode (WWLED), and white light emitting diode (WLED) at illumination of 240 μmol photons m(-2) sec(-1) were the best stress-regulatory factors. PAR without P & low N conditions yielded high biomass with 33% lipids containing increased C16:0 and C18:0 saturated fatty acids, and reduced unsaturated fatty acids (UFAs) (oleic, linoleic, and α/γ-linolenic). WWLED and WLED without P conditions also yielded high biomass, but 25% lipids with increased amounts of UFAs. Red light emitting diode (RLED) without P & low N conditions yielded 46% lipids with lowest biomass. PAR and WWLED & WLED illuminated conditions were found suitable respectively for biodiesel feedstock lipids and UFA-rich lipids for multiple applications.

  2. Antiaging effects of astaxanthin-rich alga Haematococcus pluvialis on fruit flies under oxidative stress.

    PubMed

    Huangfu, Jieqiong; Liu, Jin; Sun, Zheng; Wang, Mingfu; Jiang, Yue; Chen, Zhen-Yu; Chen, Feng

    2013-08-14

    The microalga Haematococcus pluvialis (HP) is the best natural producer of astaxanthin (AX), which is a potent antioxidant with broad health benefits. The present study investigated the antiaging potential of HP biomass using the fruit fly Drosophila melanogaster as the animal model. The results showed that in wild-type flies the treatment of HP induced the early mortality at a concentration of 20 mg/mL, which was associated with the decreased enzymatic activities of CuZn-superoxide dismutase (SOD1) and Mn-superoxide dismutase (SOD2) as well as the down-regulation of SOD1, SOD2, and catalase (CAT) at the transcriptional level. In SOD(n108) mutant flies, the supplementation of HP (10 or 20 mg/mL) significantly extended their lifespan and ameliorated the age-related decline in locomotor function. Further studies suggested that HP may play a role as a complement to the defective endogenous antioxidant system to exert such lifespan elongation effects. These results, taken together, strongly support the antiaging properties of HP and its therapeutic rather than preventive potential against aging-related diseases.

  3. Evaluation of hepatoprotective and antioxidant activity of astaxanthin and astaxanthin esters from microalga-Haematococcus pluvialis.

    PubMed

    Rao, A Ranga; Sarada, R; Shylaja, M D; Ravishankar, G A

    2015-10-01

    Effect of isolated astaxanthin (ASX) and astaxanthin esters (ASXEs) from green microalga-Haematococcus pluvialis on hepatotoxicity and antioxidant activity against carbon tetrachloride (CCl4) induced toxicity in rats was compared with synthetic astaxanthin (SASX). ASX, ASXEs, and SASX, all dissolved in olive oil, fed to rats with 100 and 250 μg/kg b.w for 14 days. They were evaluated for their hepatoprotective and antioxidant activity by measuring appropriate enzymes. Among the treated groups, the SGPT, SGOT and ALP levels were decreased by 2, 2.4, and 1.5 fold in ASXEs treated group at 250 μg/Kg b.w. when compared to toxin group. Further, antioxidant enzymes catalase, glutathione, superoxide dismutase and lipid peroxidase levels were estimated in treated groups, their levels were reduced by 30-50 % in the toxin group, however these levels restored by 136.95 and 238.48 % in ASXEs treated group at 250 μg/kg. The lipid peroxidation was restored by 5.2 and 2.8 fold in ASXEs and ASX treated groups at 250 μg/kg. The total protein, albumin and bilirubin contents were decreased in toxin group, whereas normalized in ASXEs treated group. These results indicates that ASX and ASXEs have better hepatoprotection and antioxidant activity, therefore can be used in pharmaceutical and nutraceutical applications and also extended to use as food colorant.

  4. Technological process for cell disruption, extraction and encapsulation of astaxanthin from Haematococcus pluvialis.

    PubMed

    Machado, Francisco R S; Trevisol, Thalles C; Boschetto, Daiane L; Burkert, Janaína F M; Ferreira, Sandra R S; Oliveira, J Vladimir; Burkert, Carlos André V

    2016-01-20

    In this work, the effectiveness of different enzymatic techniques for cell wall disruption of Haematococcus pluvialis for the extraction of carotenoids and subsequent encapsulation of extracts in the co-polymer poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) using the Solution Enhanced Dispersion by Supercritical fluids (SEDS) technique was investigated. Glucanex(®) performed best compared with Lyticase(®) and Driselase(®). The conditions for enzymatic lysis using this enzyme preparation were established as a pH of 4.5, a temperature of 55 °C, an initial activity of β-1,3-glucanase of 0.6 U mL(-1) and a reaction time of 30 min. Enzymatic lysis assisted by ultrasound without biomass freezing was shown to be a promising and simple one-step technique for cell wall disruption, reaching 83.90% extractability. In the co-precipitation experiments, the highest encapsulation efficiency (51.21%) was obtained when using a higher biomass to dichloromethane ratio (10 mg mL(-1)) at the carotenoid extraction step and a lower pressure of precipitation (80 bar). In these conditions, spherical particles in the micrometer range (0.228 μm) were obtained.

  5. Two components of photoreceptor potential in phototaxis of the flagellated green alga Haematococcus pluvialis

    PubMed Central

    Sineshchekov, Oleg A.; Litvin, Felix F.; Keszthelyi, Lajos

    1990-01-01

    The kinetics of the photoreceptor potential of phototaxis in biflagellated green alga Haematococcus pluvialis in response to a 10-ns laser pulse of three wavelengths (465, 550, and 590 nm) were measured in single cells with 30 μs time resolution. The rise and the decay of photoinduced potential are both at least biphasic. The first component of the rise is very stable and has no measurable (<30 μs) time delay. The second component is triggered after a 120-400-μs lag period, depending on flash intensity. Its appearance is sensitive to the physiological state of the cell and the amplitude can be increased by phototactically ineffective red background illumination. The electrical generators for both components are localized in the same region of the cell membrane (on the stigma-bearing side) and these components have the same depolarizing sign. The results indicate that the photoreceptor potential in phototaxis comprises two components, which could be interpreted as light-induced charge movement within the photoreceptor molecules and changes in ion permeability of the cell membrane. PMID:19431753

  6. Subcritical water extraction and characterization of bioactive compounds from Haematococcus pluvialis microalga.

    PubMed

    Rodríguez-Meizoso, I; Jaime, L; Santoyo, S; Señoráns, F J; Cifuentes, A; Ibáñez, E

    2010-01-20

    In this work, extraction and characterization of compounds with antioxidant and antimicrobial activity from Haematococcus pluvialis microalga in red phase have been carried out. To do this, subcritical water extraction (SWE) has been combined with analytical techniques such as HPLC-DAD, HPLC-QqQ-MS and GC-MS and in vitro assays (i.e., for antioxidant and antimicrobial activity). The effect of the extraction temperature (50, 100, 150 and 200 degrees C) and solvent polarity has been studied in terms of yield and activity of the extracts. Results demonstrate that the extraction temperature has a positive influence in the extraction yield and antioxidant activity. Thus, the extraction yield achieved with this process was higher than 30% of dry weight at 200 degrees C as extraction temperature. Moreover, the extract obtained at 200 degrees C presented the highest antioxidant activity by far, while temperature does not seem to significatively affect the antimicrobial activity. Chemical composition was determined by HPLC-DAD, HPLC-QqQ-MS and GC-MS. Short chain fatty acids turned out to be responsible of the antimicrobial activity, whereas the antioxidant activity was correlated to vitamin E (present exclusively in the 200 degrees C extract), together with simple phenols, caramelization products and possible Maillard reaction products obtained during the extraction at high temperatures.

  7. Transcriptome-based analysis on carbon metabolism of Haematococcus pluvialis mutant under 15% CO2.

    PubMed

    Li, Ke; Cheng, Jun; Lu, Hongxiang; Yang, Weijuan; Zhou, Junhu; Cen, Kefa

    2017-06-01

    To elucidate the mechanism underlying the enhanced growth rate in the Haematococcus pluvialis mutated with (60)Co-γ rays and domesticated with 15% CO2, transcriptome sequencing was conducted to clarify the carbon metabolic pathways of mutant cells. The CO2 fixation rate of mutant cells increased to 2.57gL(-1)d(-1) under 15% CO2 due to the enhanced photosynthesis, carbon fixation, glycolysis pathways. The upregulation of PetH, ATPF0A and PetJ related to photosynthetic electron transport, ATP synthase and NADPH generation promoted the photosynthesis. The upregulation of genes related to Calvin cycle and ppdK promoted carbon fixation in both C3 and C4 photosynthetic pathways. The reallocation of carbon was also enhanced under 15% CO2. The 19-, 14- and 3.5-fold upregulation of FBA, TPI and PK genes, respectively, remarkably promoted the glycolysis pathways. This accelerated the conversion of photosynthetic carbon to pyruvate, which was an essential precursor for astaxanthin and lipids biosynthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Astaxanthin from Haematococcus pluvialis Prevents Oxidative Stress on Human Endothelial Cells without Toxicity

    PubMed Central

    Régnier, Philippe; Bastias, Jorge; Rodriguez-Ruiz, Violeta; Caballero-Casero, Noelia; Caballo, Carmen; Sicilia, Dolores; Fuentes, Axelle; Maire, Murielle; Crepin, Michel; Letourneur, Didier; Gueguen, Virginie; Rubio, Soledad; Pavon-Djavid, Graciela

    2015-01-01

    Astaxanthin, a powerful antioxidant, is a good candidate for the prevention of intracellular oxidative stress. The aim of the study was to compare the antioxidant activity of astaxanthin present in two natural extracts from Haematococcus pluvialis, a microalgae strain, with that of synthetic astaxanthin. Natural extracts were obtained either by solvent or supercritical extraction methods. UV, HPLC-DAD and (HPLC-(atmospheric pressure chemical ionization (APCI)+)/ion trap-MS) characterizations of both natural extracts showed similar compositions of carotenoids, but different percentages in free astaxanthin and its ester derivatives. The Trolox equivalent antioxidant capacity (TEAC) assay showed that natural extracts containing esters displayed stronger antioxidant activities than free astaxanthin. Their antioxidant capacities to inhibit intracellular oxidative stress were then evaluated on HUVEC cells. The intracellular antioxidant activity in natural extracts was approximately 90-times higher than synthetic astaxanthin (5 µM). No modification, neither in the morphology nor in the viability, of vascular human cells was observed by in vitro biocompatibility study up to 10 µM astaxanthin concentrations. Therefore, these results revealed the therapeutic potential of the natural extracts in vascular human cell protection against oxidative stress without toxicity, which could be exploited in prevention and/or treatment of cardiovascular diseases. PMID:25962124

  9. The effect of temperature on cell growth and astaxanthin accumulation of Haematococcus pluvialis during a light-dark cyclic cultivation.

    PubMed

    Wan, Minxi; Zhang, Jingkui; Hou, Dongmei; Fan, Jianhua; Li, Yuanguang; Huang, Jianke; Wang, Jun

    2014-09-01

    Haematococcus pluvialis is the best source of natural astaxanthin known as "the king of antioxidants". The mass outdoor culture is the most workable strategy for astaxanthin production, but the effects of daytime and night temperatures on the biomass concentration and astaxanthin content of H. pluvialis have received little attention. This study indicated that, raising the daytime or night temperature could stimulate night accumulation of astaxanthin until temperature up to 28°C; the night biomass loss increased firstly and then decreased along with the daytime temperature reducing; decreasing the night temperature can lessen night biomass loss; the daytime temperature of 28°C and the night temperature below 28°C were optimal for achieving high biomass and astaxanthin content. Subsequently, the outdoor culture strategy has been improved and can increase the net biomass and astaxanthin productivities by 5 and 2.9-fold as compared to the former strategy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Enhanced astaxanthin production from microalga, Haematococcus pluvialis by two-stage perfusion culture with stepwise light irradiation.

    PubMed

    Park, Joon Chul; Choi, Seung Phill; Hong, Min-Eui; Sim, Sang Jun

    2014-10-01

    For efficient astaxanthin production from the culture of green microalga, Haematococcus pluvialis, a two-stage mixotrophic culture system was established with stepwise increased light irradiance. By perfusion process, high density biomass (2.47 g/L) was achieved during the vegetative stage due to no detrimental effect of inhibitory metabolites, which was 3.09 and 1.67 times higher than batch and fed-batch processes, respectively. During the induction stage, biomass and astaxanthin were subsequently produced to the very high level 12.3 g/L and 602 mg/L, under stepwise increased light irradiance (150-450 μE/m(2)/s), respectively. These results indicate that the combinatorial approach of perfusion culture during the vegetative stage and stepwise light irradiation during the induction stage is a promising strategy for the simultaneous production of high concentration of biomass and astaxanthin in microalgae including H. pluvialis.

  11. Influences of different stress media and high light intensities on accumulation of astaxanthin in the green alga Haematococcus pluvialis.

    PubMed

    Imamoglu, Esra; Dalay, Meltem Conk; Sukan, Fazilet Vardar

    2009-10-31

    Haematococcus pluvialis Flotow is used in the aquaculture, pharmaceutical and cosmetic industries. The aim of this study was to compare the effect of various stress media and high light intensities on astaxanthin accumulation. The experimental design was achieved by four different stress media and two different light intensities for 14 days of induction period. The astaxanthin concentrations of 29.62 mg g(-1) and 30.07 mg g(-1) were obtained in distilled water with CO(2) and N-free medium, respectively, with no significant difference between them at 546 micromol photons m(-2)s(-1). Because of the morphological changes of H. pluvialis, microscopic observation was considered during the induction period to facilitate the selection of stress medium. It was clear that the rate of astaxanthin accumulation was much faster in distilled water with the addition of CO(2). The main point is that, this medium is more economical than others, especially for the large-scale productions.

  12. Fed-batch culture under illumination with blue light emitting diodes (LEDs) for astaxanthin production by Haematococcus pluvialis.

    PubMed

    Lababpour, Abdolmajid; Shimahara, Kazumichi; Hada, Keishi; Kyoui, Yoshiaki; Katsuda, Tomohisa; Katoh, Shigeo

    2005-09-01

    To increase the cell concentration and the accumulation of astaxanthin, the effects of the fed-batch addition of 10-fold-concentrated medium to supply nutrients, as well as illumination with blue light emitting diodes (LEDs), on cell growth and accumulation of astaxanthin were studied for the cultivation of Haematococcus pluvialis. Using the fed-batch addition method, the cell concentration increased above 1 mg-dry cell/cm3, and under illumination with blue LEDs, the astaxanthin concentration reached approximately 70 microg/cm3. This method was much simpler to operate than the medium replacement method in operation and enabled us to attain a higher total yield of astaxanthin.

  13. Patterns of carbohydrate and fatty acid changes under nitrogen starvation in the microalgae Haematococcus pluvialis and Nannochloropsis sp.

    PubMed

    Recht, Lee; Zarka, Aliza; Boussiba, Sammy

    2012-06-01

    The aim of this research was to study the impact of nitrogen starvation on the production of two major secondary metabolites, fatty acids and carbohydrates, in two microalgae: Nannochloropsis sp. and Haematococcus pluvialis. The major response to nitrogen starvation in both algae occurred within the first 2 days, accompanied by a sharp reduction in chlorophyll content. However, the pattern of the response differed between the two microalgae. In H. pluvialis, the first response to nitrogen starvation was intensive production of carbohydrates, accumulating to up to 63% of dry weight by day 1; on day 2, the total carbohydrate content decreased and was partially degraded, possibly to support fatty acid synthesis. Under these conditions, H. pluvialis accumulated up to 35% total fatty acids in the biomass. In Nannochloropsis sp., the immediate and major response, which was maintained throughout the entire period of exposure to stress, was production of fatty acids, accumulating up to 50% of dry weight, while carbohydrate content in the biomass remained stable at 18%. In addition, we tested the effect of the lipid-synthesis inhibitor sesamol, known to inhibit malic enzyme, on the balance between total fatty acid and carbohydrate contents in H. pluvialis and Nannochloropsis sp. In both cultures, sesamol inhibited fatty acid accumulation, but the carbohydrate content was reduced as well, albeit to a lesser extent. These findings demonstrate the complexity of the stress-response and the potential link between fatty acid and carbohydrate synthesis.

  14. Induction of salicylic acid (SA) on transcriptional expression of eight carotenoid genes and astaxanthin accumulation in Haematococcus pluvialis.

    PubMed

    Gao, Zhengquan; Meng, Chunxiao; Zhang, Xiaowen; Xu, Dong; Miao, Xuexia; Wang, Yitao; Yang, Liming; Lv, Hongxin; Chen, Lingling; Ye, Naihao

    2012-09-10

    The green alga Haematococcus pluvialis can produce large amounts of pink carotenoid astaxanthin which is a high value ketocarotenoid. In our study, transcriptional expression patterns of eight carotenoid genes in H. pluvialis in response to SA were measured using qRT-PCR. Results indicated that both 25 and 50 mg/L salicylic acid (SA) could increase astaxanthin productivity and enhance transcriptional expression of eight carotenoid genes in H. pluvialis. But these genes exhibited different expression profiles. Moreover, SA25 (25 mg/L SA) induction had a greater effect on the transcriptional expression of ipi-1, psy, pds, crtR-B and lyc (more than 6-fold up-regulation) than on ipi-2, bkt and crtO, but SA50 (50 mg/L SA) treatment had a greater impact on the transcriptional expression of ipi-1, ipi-2, pds, crtR-B and lyc than on psy, bkt and crtO. Furthermore, astaxanthin biosynthesis under SA was up-regulated mainly by ipi-1, ipi-2, psy, crtR-B, bkt and crtO at transcriptional level, lyc at post-transcriptional level and pds at both levels. Summarily, these results suggest that SA constitute molecular signals in the network of astaxanthin biosynthesis. Induction of astaxanthin accumulation by SA without any other stimuli presents an attractive application potential in astaxanthin production with H. pluvialis.

  15. A new paradigm for producing astaxanthin from the unicellular green alga Haematococcus pluvialis.

    PubMed

    Zhang, Zhen; Wang, Baobei; Hu, Qiang; Sommerfeld, Milton; Li, Yuanguang; Han, Danxiang

    2016-10-01

    The unicellular green alga Haematococcus pluvialis has been exploited as a cell factory to produce the high-value antioxidant astaxanthin for over two decades, due to its superior ability to synthesize astaxanthin under adverse culture conditions. However, slow vegetative growth under favorable culture conditions and cell deterioration or death under stress conditions (e.g., high light, nitrogen starvation) has limited the astaxanthin production. In this study, a new paradigm that integrated heterotrophic cultivation, acclimation of heterotrophically grown cells to specific light/nutrient regimes, followed by induction of astaxanthin accumulation under photoautotrophic conditions was developed. First, the environmental conditions such as pH, carbon source, nitrogen regime, and light intensity, were optimized to induce astaxanthin accumulation in the dark-grown cells. Although moderate astaxanthin content (e.g., 1% of dry weight) and astaxanthin productivity (2.5 mg L(-1)  day(-1) ) were obtained under the optimized conditions, a considerable number of cells died off when subjected to stress for astaxanthin induction. To minimize the susceptibility of dark-grown cells to light stress, the algal cells were acclimated, prior to light induction of astaxanthin biosynthesis, under moderate illumination in the presence of nitrogen. Introduction of this strategy significantly reduced the cell mortality rate under high-light and resulted in increased cellular astaxanthin content and astaxanthin productivity. The productivity of astaxanthin was further improved to 10.5 mg L(-1)  day(-1) by implementation of such a strategy in a bubbling column photobioreactor. Biochemical and physiological analyses suggested that rebuilding of photosynthetic apparatus including D1 protein and PsbO, and recovery of PSII activities, are essential for acclimation of dark-grown cells under photo-induction conditions. Biotechnol. Bioeng. 2016;113: 2088-2099. © 2016 The Authors

  16. A new paradigm for producing astaxanthin from the unicellular green alga Haematococcus pluvialis

    PubMed Central

    Zhang, Zhen; Wang, Baobei; Hu, Qiang; Sommerfeld, Milton

    2016-01-01

    ABSTRACT The unicellular green alga Haematococcus pluvialis has been exploited as a cell factory to produce the high‐value antioxidant astaxanthin for over two decades, due to its superior ability to synthesize astaxanthin under adverse culture conditions. However, slow vegetative growth under favorable culture conditions and cell deterioration or death under stress conditions (e.g., high light, nitrogen starvation) has limited the astaxanthin production. In this study, a new paradigm that integrated heterotrophic cultivation, acclimation of heterotrophically grown cells to specific light/nutrient regimes, followed by induction of astaxanthin accumulation under photoautotrophic conditions was developed. First, the environmental conditions such as pH, carbon source, nitrogen regime, and light intensity, were optimized to induce astaxanthin accumulation in the dark‐grown cells. Although moderate astaxanthin content (e.g., 1% of dry weight) and astaxanthin productivity (2.5 mg L−1 day−1) were obtained under the optimized conditions, a considerable number of cells died off when subjected to stress for astaxanthin induction. To minimize the susceptibility of dark‐grown cells to light stress, the algal cells were acclimated, prior to light induction of astaxanthin biosynthesis, under moderate illumination in the presence of nitrogen. Introduction of this strategy significantly reduced the cell mortality rate under high‐light and resulted in increased cellular astaxanthin content and astaxanthin productivity. The productivity of astaxanthin was further improved to 10.5 mg L−1 day−1 by implementation of such a strategy in a bubbling column photobioreactor. Biochemical and physiological analyses suggested that rebuilding of photosynthetic apparatus including D1 protein and PsbO, and recovery of PSII activities, are essential for acclimation of dark‐grown cells under photo‐induction conditions. Biotechnol. Bioeng. 2016;113: 2088–2099.

  17. Quantitative proteomic analysis of thylakoid from two microalgae (Haematococcus pluvialis and Dunaliella salina) reveals two different high light-responsive strategies.

    PubMed

    Gu, Wenhui; Li, Huan; Zhao, Peipei; Yu, Ruixue; Pan, Guanghua; Gao, Shan; Xie, Xiujun; Huang, Aiyou; He, Linwen; Wang, Guangce

    2014-10-22

    Under high light (HL) stress, astaxanthin-accumulating Haematococcus pluvialis and β-carotene-accumulating Dunaliella salina showed different responsive patterns. To elucidate cellular-regulating strategies photosynthetically and metabolically, thylakoid membrane proteins in H. pluvialis and D. salina were extracted and relatively quantified after 0 h, 24 h and 48 h of HL stress. Proteomic analysis showed that three subunits of the cytochrome b6/f complex were greatly reduced under HL stress in H. pluvialis, while they were increased in D. salina. Additionally, the major subunits of both photosystem (PS) II and PSI reaction center proteins were first reduced and subsequently recovered in H. pluvialis, while they were gradually reduced in D. salina. D. salina also showed a greater ability to function using the xanthophyll-cycle and the cyclic photosynthetic electron transfer pathway compared to H. pluvialis. We propose a reoriented and effective HL-responsive strategy in H. pluvialis, enabling it to acclimate under HL. The promising metabolic pathway described here contains a reorganized pentose phosphate pathway, Calvin cycle and glycolysis pathway participating in carbon sink formation under HL in H. pluvialis. Additionally, the efficient carbon reorientation strategy in H. pluvialis was verified by elevated extracellular carbon assimilation and rapid conversion into astaxanthin.

  18. Accumulation of astaxanthin by a new Haematococcus pluvialis strain BM1 from the white sea coastal rocks (Russia).

    PubMed

    Chekanov, Konstantin; Lobakova, Elena; Selyakh, Irina; Semenova, Larisa; Sidorov, Roman; Solovchenko, Alexei

    2014-08-15

    We report on a novel arctic strain BM1 of a carotenogenic chlorophyte from a coastal habitat with harsh environmental conditions (wide variations in solar irradiance, temperature, salinity and nutrient availability) identified as Haematococcus pluvialis Flotow. Increased (25‰) salinity exerted no adverse effect on the growth of the green BM1 cells. Under stressful conditions (high light, nitrogen and phosphorus deprivation), green vegetative cells of H. pluvialis BM1 grown in BG11 medium formed non-motile palmelloid cells and, eventually, hematocysts capable of a massive accumulation of the keto-carotenoid astaxanthin with a high nutraceutical and therapeutic potential. Routinely, astaxanthin was accumulated at the level of 4% of the cell dry weight (DW), reaching, under prolonged stress, 5.5% DW. Astaxanthin was predominantly accumulated in the form of mono- and diesters of fatty acids from C16 and C18 families. The palmelloids and hematocysts were characterized by the formation of red-colored cytoplasmic lipid droplets, increasingly large in size and number. The lipid droplets tended to merge and occupied almost the entire volume of the cell at the advanced stages of stress-induced carotenogenesis. The potential application of the new strain for the production of astaxanthin is discussed in comparison with the H. pluvialis strains currently employed in microalgal biotechnology.

  19. Organization of Astaxanthin within Oil Bodies of Haematococcus pluvialis Studied with Polarization-Dependent Harmonic Generation Microscopy

    PubMed Central

    Tokarz, Danielle; Cisek, Richard; El-Ansari, Omar; Espie, George S.; Fekl, Ulrich; Barzda, Virginijus

    2014-01-01

    Nonlinear optical microscopy was used to image the localization of astaxanthin accumulation in the green alga, Haematococcus pluvialis. Polarization-in, polarization-out (PIPO) second harmonic generation (SHG) and third harmonic generation (THG) microscopy was applied to study the crystalline organization of astaxanthin molecules in light-stressed H. pluvialis in vivo. Since astaxanthin readily forms H- and J-aggregates in aqueous solutions, PIPO THG studies of astaxanthin aggregates contained in red aplanospores were compared to PIPO THG of in vitro self-assembled H- and J-aggregates of astaxanthin. The PIPO THG data clearly showed an isotropic organization of astaxanthin in red aplanospores of H. pluvialis. This is in contrast to the highly anisotropic organization of astaxanthin in synthetic H- and J-aggregates, which showed to be uniaxial. Since carotenoids in vitro preferentially form H- and J-aggregates, but in vivo form a randomly organized structure, this implies that astaxanthin undergoes a different way of packing in biological organisms, which is either due to the unique physical environment of the alga or is controlled enzymatically. PMID:25215522

  20. Organization of astaxanthin within oil bodies of Haematococcus pluvialis studied with polarization-dependent harmonic generation microscopy.

    PubMed

    Tokarz, Danielle; Cisek, Richard; El-Ansari, Omar; Espie, George S; Fekl, Ulrich; Barzda, Virginijus

    2014-01-01

    Nonlinear optical microscopy was used to image the localization of astaxanthin accumulation in the green alga, Haematococcus pluvialis. Polarization-in, polarization-out (PIPO) second harmonic generation (SHG) and third harmonic generation (THG) microscopy was applied to study the crystalline organization of astaxanthin molecules in light-stressed H. pluvialis in vivo. Since astaxanthin readily forms H- and J-aggregates in aqueous solutions, PIPO THG studies of astaxanthin aggregates contained in red aplanospores were compared to PIPO THG of in vitro self-assembled H- and J-aggregates of astaxanthin. The PIPO THG data clearly showed an isotropic organization of astaxanthin in red aplanospores of H. pluvialis. This is in contrast to the highly anisotropic organization of astaxanthin in synthetic H- and J-aggregates, which showed to be uniaxial. Since carotenoids in vitro preferentially form H- and J-aggregates, but in vivo form a randomly organized structure, this implies that astaxanthin undergoes a different way of packing in biological organisms, which is either due to the unique physical environment of the alga or is controlled enzymatically.

  1. Carotenoid genes transcriptional regulation for astaxanthin accumulation in fresh water unicellular alga Haematococcus pluvialis by gibberellin A3 (GA3).

    PubMed

    Gao, Zhengquan; Meng, Chunxiao; Gao, Hongzheng; Li, Yan; Zhang, Xiaowen; Xu, Dong; Zhou, Shitan; Liu, Banghui; Su, Yuanfeng; Ye, Naihao

    2013-12-01

    The fresh water unicellular alga Haematococcus pluvialis is a promising natural source of astaxanthin. The present study investigated the transcriptional expression of carotenoid genes for astaxanthin accumulation in H. pluvialis using real-time fluorescence quantitative PCR (qRT-PCR). With treatments of 20 and 40 mg/L of gibberllin A3 (GA3), five genes ipi-1, ipi-2, psy, pds and bkt2 were up-regulated with different expression profiles. GA20 (20 mg/L of GA3) treatment had a greater effect on transcriptional expression of bkt2 than on ipi-1 ipi-2, psy and pds (> 4-fold up-regulation). However, GA40 (40 mg/L of GA3) induced more transcriptional expression of ipi-2, psy and bkt2 than both ipi-1 and pds. The expression of lyc, crtR-B and crtO for astaxanthin biosynthesis was not affected by GA3 in H. piuvialis. In the presence of GA3, astaxanthin biosynthesis genes of ipi-1, pds and bkt2 were up-regulated at transcriptional level, psy at post-transcriptional level, whereas ipi-2 was up-regulated at both levels. The study could potentially lead to a scale application of exogenous GA3 in astaxanthin production with H. pluvialis just like GAs perform in increasing crops production and it would provide new insight about the multifunctional roles of carotenogenesis in response to GA3.

  2. Optimal design of scalable photo-bioreactor for phototropic culturing of Haematococcus pluvialis.

    PubMed

    Yoo, Jae Jun; Choi, Seung Phill; Kim, Byung Woo; Sim, Sang Jun

    2012-01-01

    The unicellular green microalgae, Haematococcus pluvialis, has been examined as a microbial source for the production of astaxanthin, which has been suggested as a food supplement for humans and is also prescribed as an ingredient in eye drops because of its powerful anti-oxidant properties. In this study, we estimated the effects of the slope of a V-shaped bottom design, the volumetric flow rate of air, height/diameter (H/D) ratio, and diameter of an air sparger on the performance of a photo-bioreactor. These parameters were selected because they are recognized as important factors effecting the mixing that produces increased cell density in the reactor. The mixing effect can be measured by changes in optical density in the bioreactor over a period of time. A 6 L indoor photo-bioreactor was prepared in a short time period of 24 h for the performance study. A bioreactor designed with a V-shaped bottom with a slope of 60° showed an optical density change of 0.052 at 680 nm, which was sixfold less than the change in a photo-bioreactor designed with a flat bottom. Studies exploring the effects of bioreactor configuration and a porous metal sparger with a 10 μm pore size showed the best performance at an H/D ratio of 6:1 and a sparger diameter of 1.3 cm, respectively. The optimal rate of air flow was 0.2 vvm. The indoor culture of microalgae in the photo-bioreactor was subsequently carried for an application study using the optimal values established for the important factors. The indoor culture system was composed of a light source controlled according to cell phase, a carbon dioxide feeder, a bag-type reactor with an H/D ratio of 6:1, and a temperature controller. Results demonstrated the efficient production of microalgal cells and astaxanthin in the amounts of 2.62 g/L and 78.37 mg/L, respectively, when using adequate hydrodynamic mixing. Furthermore, the optimal design of a photo-bioreactor can be applied for the phototropic culturing of other microalgae for

  3. Gradient domestication of Haematococcus pluvialis mutant with 15% CO2 to promote biomass growth and astaxanthin yield.

    PubMed

    Cheng, Jun; Li, Ke; Yang, Zongbo; Lu, Hongxiang; Zhou, Junhu; Cen, Kefa

    2016-09-01

    In order to increase biomass yield and reduce culture cost of Haematococcus pluvialis with flue gas from coal-fired power plants, a screened mutant by nuclear irradiation was gradually domesticated with 15% CO2 to promote biomass dry weight and astaxanthin yield. The biomass yield of mutant after 10 generations of 15% CO2 domestication increased to 1.3 times as that with air. With the optimization of nitrogen and phosphorus concentration, the biomass dry weight was further increased by 62%. The astaxanthin yield induced with 15% CO2 and high light of 135 μmol photons m(-2) s(-1) increased to 87.4mg/L, which was 6 times higher than that induced with high light in air.

  4. Fed-batch culture of astaxanthin-rich Haematococcus pluvialis by exponential nutrient feeding and stepwise light supplementation.

    PubMed

    Kang, Chang Duk; Han, Se Jong; Choi, Seung Phill; Sim, Sang Jun

    2010-01-01

    A fed-batch culture process followed by subsequent photoautotrophic induction was established for the high density culture of astaxanthin-rich Haematococcus pluvialis using a CO(2)-fed flat type photobioreactor under unsynchronized illumination. Fed-batch culture was performed with an exponential feeding strategy of the growth-limiting nutrients, nitrate and phosphate, concurrently with the stepwise supplementation of light depending on the cell concentration. During the growth phase, a biomass of 1.47 g/L was obtained at a biomass productivity of 0.33 g/L/day. Photoautotrophic induction of the well-grown vegetative cells was performed consecutively by increasing the light intensity to 400 micromol photon/m(2)/s, while keeping the other conditions in the CO(2)-fed flat type photobioreactor fixed, yielding an astaxanthin production of 190 mg/L at an astaxanthin productivity of 14 mg/L/day. The proposed sequential photoautotrophic process has high potential as simple and productive process for the production of valuable Haematococcus astaxanthin.

  5. Enhanced autotrophic astaxanthin production from Haematococcus pluvialis under high temperature via heat stress-driven Haber-Weiss reaction.

    PubMed

    Hong, Min-Eui; Hwang, Sung Kwan; Chang, Won Seok; Kim, Byung Woo; Lee, Jeewon; Sim, Sang Jun

    2015-06-01

    High temperatures (30-36 °C) inhibited astaxanthin accumulation in Haematococcus pluvialis under photoautotrophic conditions. The depression of carotenogenesis was primarily attributed to excess intracellular less reactive oxygen species (LROS; O2 (-) and H2O2) levels generated under high temperature conditions. Here, we show that the heat stress-driven inefficient astaxanthin production was improved by accelerating the iron-catalyzed Haber-Weiss reaction to convert LROS into more reactive oxygen species (MROS; O2 and OH·), thereby facilitating lipid peroxidation. As a result, during 18 days of photoautotrophic induction, the astaxanthin concentration of cells cultured in high temperatures in the presence of iron (450 μM) was dramatically increased by 75 % (30 °C) and 133 % (36 °C) compared to that of cells exposed to heat stress alone. The heat stress-driven Haber-Weiss reaction will be useful for economically producing astaxanthin by reducing energy cost and enhancing photoautotrophic astaxanthin production, particularly outdoors utilizing natural solar radiation including heat and light for photo-induction of H. pluvialis.

  6. Changes of Photosynthetic Behaviors and Photoprotection during Cell Transformation and Astaxanthin Accumulation in Haematococcus pluvialis Grown Outdoors in Tubular Photobioreactors.

    PubMed

    Zhang, Litao; Su, Fang; Zhang, Chunhui; Gong, Fengying; Liu, Jianguo

    2016-12-26

    The cell transformation from green motile cells to non-motile cells and astaxanthin accumulation can be induced in the green alga Haematococcus pluvialis cultured outdoors. In the initial 3 d of incubation (cell transformation phase), light absorption and photosynthetic electron transport became more efficient. After five days of incubation (astaxanthin accumulation phase), the light absorption per active reaction center (ABS/RC) increased, but the efficiency of electron transport (ψo) and the quantum yield of electron transport (φEo) decreased with increased time, indicating that the capacity of photosynthetic energy utilization decreased significantly during astaxanthin accumulation, leading to an imbalance between photosynthetic light absorption and energy utilization. It would inevitably aggravate photoinhibition under high light, e.g., at midday. However, the level of photoinhibition in H. pluvialis decreased as the incubation time increased, which is reflected by the fact that Fv/Fm determined at midday decreased significantly in the initial 3 d of incubation, but was affected very little after seven days of incubation, compared with that determined at predawn. This might be because the non-photochemical quenching, plastid terminal oxidase, photosystem I cyclic electron transport, defensive enzymes and the accumulated astaxanthin can protect cells against photoinhibition.

  7. Three-Dimensional Ultrastructural Study of Oil and Astaxanthin Accumulation during Encystment in the Green Alga Haematococcus pluvialis

    PubMed Central

    Matsuura, Hazuki; Nango, Nobuhito; Hirata, Aiko; Kawano, Shigeyuki

    2013-01-01

    Haematococcus pluvialis is a freshwater species of green algae and is well known for its accumulation of the strong antioxidant astaxanthin, which is used in aquaculture, various pharmaceuticals, and cosmetics. High levels of astaxanthin are present in cysts, which rapidly accumulate when the environmental conditions become unfavorable for normal cell growth. It is not understood, however, how accumulation of high levels of astaxanthin, which is soluble in oil, becomes possible during encystment. Here, we performed ultrastructural 3D reconstruction based on over 350 serial sections per cell to visualize the dynamics of astaxanthin accumulation and subcellular changes during the encystment of H. pluvialis. This study showcases the marked changes in subcellular elements, such as chloroplast degeneration, in the transition from green coccoid cells to red cyst cells during encystment. In green coccoid cells, chloroplasts accounted for 41.7% of the total cell volume, whereas the relative volume of astaxanthin was very low (0.2%). In contrast, oil droplets containing astaxanthin predominated in cyst cells (52.2%), in which the total chloroplast volume was markedly decreased (9.7%). Volumetric observations also demonstrated that the relative volumes of the cell wall, starch grains, pyrenoids, mitochondria, the Golgi apparatus, and the nucleus in a cyst cell are smaller than those in green coccid cells. Our data indicated that chloroplasts are degraded, resulting in a net-like morphology, but do not completely disappear, even at the red cyst stage. PMID:23326471

  8. Screening of Astaxanthin-Hyperproducing Haematococcus pluvialis Using Fourier Transform Infrared (FT-IR) and Raman Microspectroscopy.

    PubMed

    Liu, Jinghua; Huang, Qing

    2016-06-13

    Haematococcus pluvialis has promising applications owing to its ability to accumulate astaxanthin under stress conditions. In order to acquire higher astaxanthin productivity from H. pluvialis, it is critical not only to develop efficient mutagenesis techniques, but also to establish rapid and effective screening methods which are highly demanded in current research and application practice. In this work, we therefore attempted to develop a new approach to screening the astaxanthin-hyperproducing strains based on spectroscopic tools. Using Fourier transform infrared (FT-IR) and Raman microspectroscopy, we have achieved rapid and quantitative analysis of the algal cells in terms of astaxanthin, β-carotene, proteins, lipids, and carbohydrates. In particular, we have found that the ratio of the IR absorption band at 1740 cm(-1) to the band at 1156 cm(-1) can be utilized for identifying astaxanthin-hyperproducing strains. This work may therefore open a new avenue for developing high-throughput screening methods necessary for the microbial mutant breeding industry.

  9. Three-dimensional ultrastructural study of oil and astaxanthin accumulation during encystment in the green alga Haematococcus pluvialis.

    PubMed

    Wayama, Marina; Ota, Shuhei; Matsuura, Hazuki; Nango, Nobuhito; Hirata, Aiko; Kawano, Shigeyuki

    2013-01-01

    Haematococcus pluvialis is a freshwater species of green algae and is well known for its accumulation of the strong antioxidant astaxanthin, which is used in aquaculture, various pharmaceuticals, and cosmetics. High levels of astaxanthin are present in cysts, which rapidly accumulate when the environmental conditions become unfavorable for normal cell growth. It is not understood, however, how accumulation of high levels of astaxanthin, which is soluble in oil, becomes possible during encystment. Here, we performed ultrastructural 3D reconstruction based on over 350 serial sections per cell to visualize the dynamics of astaxanthin accumulation and subcellular changes during the encystment of H. pluvialis. This study showcases the marked changes in subcellular elements, such as chloroplast degeneration, in the transition from green coccoid cells to red cyst cells during encystment. In green coccoid cells, chloroplasts accounted for 41.7% of the total cell volume, whereas the relative volume of astaxanthin was very low (0.2%). In contrast, oil droplets containing astaxanthin predominated in cyst cells (52.2%), in which the total chloroplast volume was markedly decreased (9.7%). Volumetric observations also demonstrated that the relative volumes of the cell wall, starch grains, pyrenoids, mitochondria, the Golgi apparatus, and the nucleus in a cyst cell are smaller than those in green coccid cells. Our data indicated that chloroplasts are degraded, resulting in a net-like morphology, but do not completely disappear, even at the red cyst stage.

  10. Enhancement of microbial diversity and methane yield by bacterial bioaugmentation through the anaerobic digestion of Haematococcus pluvialis.

    PubMed

    Aydin, Sevcan

    2016-06-01

    Microalgae has recalcitrant cell walls that may limit digestibility and, therefore, reduce bioenergy production. In light of the fact that cellulose can increase the cell wall recalcitrance of the Haematococcus pluvialis species of microalgae, the objective of this research was to examine how bioaugmentation with the Clostridium thermocellum at various inoculum ratios represents a viable method by which the CH4 production of microalgae can be enhanced. The results of the investigation revealed that bioaugmentation with C. thermocellum increased the degradation of H. pluvialis biomass and resulted in a 18-38 % increase in methane production as a result of increased cell disruption. In addition, the use of Illumina Miseq sequencing highlighted that the bacterial and archaeal diversity and quantities in the genus were enhanced as a result of the addition of C. thermocellum and this, in itself, improved the efficiency of the biodegradation. Bioaugmentation with C. thermocellum (%15) was also determined to represent the most energy-efficiency method of producing methane.

  11. Enhancing the growth rate and astaxanthin yield of Haematococcus pluvialis by nuclear irradiation and high concentration of carbon dioxide stress.

    PubMed

    Cheng, Jun; Li, Ke; Yang, Zongbo; Zhou, Junhu; Cen, Kefa

    2016-03-01

    Unicellular green microalgae Haematococcus pluvialis was mutated with (60)Co-γ irradiation to promote growth rate and increase astaxanthin yield under high concentration of CO2 stress. The average specific growth rate of H. pluvialis mutated with 4000 Gy γ-ray irradiation was increased by 15% compared with the original strain with air aeration. The mutant grew best with 6% CO2 (the maximum specific growth rate was 0.60/d) when it was cultured with high concentrations of CO2 (2-10%). The peak biomass productivity (0.16 g/L/d) of the mutant cultured with 6% CO2 was 82% higher than that of the mutant with air. The astaxanthin yield and lipid content of the mutant induced with 6% CO2 and high light (108 μmol photons m(-2) s(-1)) increased to 46.0mg/L and 45.9%, which were 2.4 and 1.3 times higher than those of the wild-type strain, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Changes of Photosynthetic Behaviors and Photoprotection during Cell Transformation and Astaxanthin Accumulation in Haematococcus pluvialis Grown Outdoors in Tubular Photobioreactors

    PubMed Central

    Zhang, Litao; Su, Fang; Zhang, Chunhui; Gong, Fengying; Liu, Jianguo

    2016-01-01

    The cell transformation from green motile cells to non-motile cells and astaxanthin accumulation can be induced in the green alga Haematococcus pluvialis cultured outdoors. In the initial 3 d of incubation (cell transformation phase), light absorption and photosynthetic electron transport became more efficient. After five days of incubation (astaxanthin accumulation phase), the light absorption per active reaction center (ABS/RC) increased, but the efficiency of electron transport (ψo) and the quantum yield of electron transport (φEo) decreased with increased time, indicating that the capacity of photosynthetic energy utilization decreased significantly during astaxanthin accumulation, leading to an imbalance between photosynthetic light absorption and energy utilization. It would inevitably aggravate photoinhibition under high light, e.g., at midday. However, the level of photoinhibition in H. pluvialis decreased as the incubation time increased, which is reflected by the fact that Fv/Fm determined at midday decreased significantly in the initial 3 d of incubation, but was affected very little after seven days of incubation, compared with that determined at predawn. This might be because the non-photochemical quenching, plastid terminal oxidase, photosystem I cyclic electron transport, defensive enzymes and the accumulated astaxanthin can protect cells against photoinhibition. PMID:28035956

  13. Comparative analyses of lipidomes and transcriptomes reveal a concerted action of multiple defensive systems against photooxidative stress in Haematococcus pluvialis.

    PubMed

    Gwak, Yunho; Hwang, Yong-sic; Wang, Baobei; Kim, Minju; Jeong, Jooyeon; Lee, Choul-Gyun; Hu, Qiang; Han, Danxiang; Jin, EonSeon

    2014-08-01

    Haematococcus pluvialis cells predominantly remain in the macrozooid stage under favourable environmental conditions but are rapidly differentiated into haematocysts upon exposure to various environmental stresses. Haematocysts are characterized by massive accumulations of astaxanthin sequestered in cytosolic oil globules. Lipidomic analyses revealed that synthesis of the storage lipid triacylglycerol (TAG) was substantially stimulated under high irradiance. Simultaneously, remodelling of membrane glycerolipids occurred as a result of dramatic reductions in chloroplast membrane glycolipids but remained unchanged or declined slightly in extraplastidic membrane glycerolipids. De novo assembly of transcriptomes revealed the genomic and metabolic features of this unsequenced microalga. Comparative transcriptomic analysis showed that so-called resting cells (haematocysts) may be more active than fast-growing vegetative cells (macrozooids) regarding metabolic pathways and functions. Comparative transcriptomic analyses of astaxanthin biosynthesis suggested that the non-mevalonate pathway mediated the synthesis of isopentenyl diphosphate, as the majority of genes involved in subsequent astaxanthin biosynthesis were substantially up-regulated under high irradiance, with the genes encoding phytoene synthase, phytoene desaturase, and β-carotene hydroxylase identified as the most prominent regulatory components. Accumulation of TAG under high irradiance was attributed to moderate up-regulation of de novo fatty acid biosynthesis at the gene level as well as to moderate elevation of the TAG assembly pathways. Additionally, inferred from transcriptomic differentiation, an increase in reactive oxygen species (ROS) scavenging activity, a decrease in ROS production, and the relaxation of over-reduction of the photosynthetic electron transport chain will work together to protect against photooxidative stress in H. pluvialis under high irradiance. © The Author 2014. Published by

  14. The effect of various antioxidants on the degradation of O/W microemulsions containing esterified astaxanthins from Haematococcus pluvialis.

    PubMed

    Zhou, Qingxin; Xu, Jie; Yang, Shu; Xue, Yong; Zhang, Ting; Wang, Jingfeng; Xue, Changhu

    2015-01-01

    Esterified astaxanthins are used as functional nutraceuticals and pigments in many food products. Unfortunately, the utilization is currently limited due to their chemical instability and poor water-solubility. In this study, esterified astaxanthins were quantified and purified from Haematococcus pluvialis using a novel and precise approach. By HPLC-(+)APCI-MS/MS, twenty esterified astaxanthin molecular species were identified, of which classified into eight monoester forms (approximately 85%, w/w) and twelve diester forms (approximately 15%, w/w), depending on the number of fatty acids that bind thereto. The MS data showed that the predominant fatty acids in astaxanthin esters of H. pluvialis are usually a long chain fatty acid with 16~18 carbon atoms, such as C18:1, C18:2, C18:3, C18:4, C16:0, C16:1. The purity of the esterified astaxanthins was determined to be 96.8±1.2% after purification. A well water-dispersible microemulsion was fabricated using high purity esterified astaxanthins, ethyl butyrate, Tween 80 and ethanol; and that emulsion exhibited a mean particle radius around 60 nm. The chemical degradation of esterified astaxanthins was monitored under accelerated stress storage conditions. After storage for 20 days, the results indicated that the degradation of esterified astaxanthins was effectively slowed by the addition of antioxidants to the microemulsions. By investigating the dependence of the chemical degradation of the esterified astaxanthins in O/W microemulsions on the concentration of the additives, it was concluded that the effectiveness of the additives at inhibiting the degradation of the esterified astaxanthins decreased in the following order: EDTA > ascorbic acid > vitamin E acetate. The utilization of antioxidants in combination was less effective than using them individually. These results provide information for designing effective delivery systems, thereby delaying the chemical degradation of esterified astaxanthins in foods

  15. Comparative analyses of lipidomes and transcriptomes reveal a concerted action of multiple defensive systems against photooxidative stress in Haematococcus pluvialis

    PubMed Central

    Gwak, Yunho; Hwang, Yong-sic; Wang, Baobei; Kim, Minju; Jeong, Jooyeon; Lee, Choul-Gyun; Hu, Qiang; Han, Danxiang; Jin, EonSeon

    2014-01-01

    Haematococcus pluvialis cells predominantly remain in the macrozooid stage under favourable environmental conditions but are rapidly differentiated into haematocysts upon exposure to various environmental stresses. Haematocysts are characterized by massive accumulations of astaxanthin sequestered in cytosolic oil globules. Lipidomic analyses revealed that synthesis of the storage lipid triacylglycerol (TAG) was substantially stimulated under high irradiance. Simultaneously, remodelling of membrane glycerolipids occurred as a result of dramatic reductions in chloroplast membrane glycolipids but remained unchanged or declined slightly in extraplastidic membrane glycerolipids. De novo assembly of transcriptomes revealed the genomic and metabolic features of this unsequenced microalga. Comparative transcriptomic analysis showed that so-called resting cells (haematocysts) may be more active than fast-growing vegetative cells (macrozooids) regarding metabolic pathways and functions. Comparative transcriptomic analyses of astaxanthin biosynthesis suggested that the non-mevalonate pathway mediated the synthesis of isopentenyl diphosphate, as the majority of genes involved in subsequent astaxanthin biosynthesis were substantially up-regulated under high irradiance, with the genes encoding phytoene synthase, phytoene desaturase, and β-carotene hydroxylase identified as the most prominent regulatory components. Accumulation of TAG under high irradiance was attributed to moderate up-regulation of de novo fatty acid biosynthesis at the gene level as well as to moderate elevation of the TAG assembly pathways. Additionally, inferred from transcriptomic differentiation, an increase in reactive oxygen species (ROS) scavenging activity, a decrease in ROS production, and the relaxation of over-reduction of the photosynthetic electron transport chain will work together to protect against photooxidative stress in H. pluvialis under high irradiance. PMID:24821952

  16. Modulation of photosynthetic activity and photoprotection in Haematococcus pluvialis cells during their conversion into haematocysts and back.

    PubMed

    Chekanov, Konstantin; Lukyanov, Alexander; Boussiba, Sammy; Aflalo, Claude; Solovchenko, Alexei

    2016-06-01

    The engagement of different photoprotective mechanisms in the cells of the carotenogenic astaxanthin-accumulating chlorophyte Haematococcus pluvialis (i) under favorable conditions, (ii) in the course of stress-induced haematocyst formation and (iii) during recovery from the stress was studied. To this end, we followed the changes in primary photochemistry, electron flow at the acceptor side of photosystem II, and non-photochemical quenching (NPQ) using PAM chlorophyll fluorimetry. A general trend recorded in the stressed cells undergoing transition to haematocysts (and reversed during recovery from the stress) was a gradual reduction of the photosynthetic apparatus accompanied by down-regulation of energy-dependent photoprotective mechanisms such as NPQ, along with the accumulation of astaxanthin. On this background, a transient up-regulation of the photosynthetic activity was detected at the intermediated stages (20-50 h of the stress exposure) of haematocyst formation. This phenomenon was tentatively related with the peak of metabolic activity found earlier in the forming haematocysts. The role of secondary carotenogenesis coupled with a reversible transition from 'active' (energy-dependent) to 'passive' photoprotective mechanisms in the extremely high stress tolerance of carotenogenic phototrophs is discussed.

  17. An economic assessment of astaxanthin production by large scale cultivation of Haematococcus pluvialis.

    PubMed

    Li, Jian; Zhu, Daling; Niu, Jianfeng; Shen, Songdong; Wang, Guangce

    2011-01-01

    Although natural sources have long been exploited for astaxanthin production, it is still uncertain if natural astaxanthin can be produced at lower cost than that of synthetic astaxanthin or not. In order to give a comprehensive cost analysis of astaxanthin production from Haematococcus, a pilot plant with two large scale outdoor photobioreactors and a raceway pond was established and operated for 2 years to develop processes for astaxanthin production from Haematococcus. The developed processes were scaled up to a hypothetical plant with a production capacity about 900 kg astaxanthin per year, and the process economics was preliminarily assessed. Based on the analysis, the production cost of astaxanthin and microalgae biomass can be as low as $718/kg and $18/kg respectively. The results are very encouraging because the estimated cost might be lower than that of chemically synthesized astaxanthin.

  18. From genetic improvement to commercial-scale mass culture of a Chilean strain of the green microalga Haematococcus pluvialis with enhanced productivity of the red ketocarotenoid astaxanthin

    PubMed Central

    Gómez, Patricia I.; Inostroza, Ingrid; Pizarro, Mario; Pérez, Jorge

    2013-01-01

    Astaxanthin is a red ketocarotenoid, widely used as a natural red colourant in marine fish aquaculture and poultry and, recently, as an antioxidant supplement for humans and animals. The green microalga Haematococcus pluvialis is one of the richest natural sources of this pigment. However, its slow growth rate and complex life cycle make mass culture difficult for commercial purposes. The aims of this research were (i) to standardize and apply a genetic improvement programme to a Chilean strain of H. pluvialis in order to improve its carotenogenic capacity and (ii) to evaluate the performance of a selected mutant strain in commercial-sized (125 000 L) open ponds in the north of Chile. Haematococcus pluvialis strain 114 was mutated by ethyl methanesulfonate. The level of mutagen dose (exposure time and concentration) was one that induced at least 90 % mortality. Surviving colonies were screened for resistance to the carotenoid biosynthesis inhibitor diphenylamine (25 µM). Resistant mutants were grown in a 30-mL volume for 30 days, after which the total carotenoid content was determined by spectrophotometry. Tens of mutants with improved carotenogenic capacity compared with the wild-type strain were isolated by the application of these standardized protocols. Some mutants exhibited curious morphological features such as spontaneous release of astaxanthin and loss of flagella. One of the mutants was grown outdoors in commercial-sized open ponds of 125 000 L in the north of Chile. Grown under similar conditions, the mutant strain accumulated 30 % more astaxanthin than the wild-type strain on a per dry weight basis and 72 % more on a per culture volume basis. We show that random mutagenesis/selection is an effective strategy for genetically improving strains of H. pluvialis and that improved carotenogenic capacity is maintained when the volume of the cultures is scaled up to a commercial size. PMID:23789055

  19. From genetic improvement to commercial-scale mass culture of a Chilean strain of the green microalga Haematococcus pluvialis with enhanced productivity of the red ketocarotenoid astaxanthin.

    PubMed

    Gómez, Patricia I; Inostroza, Ingrid; Pizarro, Mario; Pérez, Jorge

    2013-01-01

    Astaxanthin is a red ketocarotenoid, widely used as a natural red colourant in marine fish aquaculture and poultry and, recently, as an antioxidant supplement for humans and animals. The green microalga Haematococcus pluvialis is one of the richest natural sources of this pigment. However, its slow growth rate and complex life cycle make mass culture difficult for commercial purposes. The aims of this research were (i) to standardize and apply a genetic improvement programme to a Chilean strain of H. pluvialis in order to improve its carotenogenic capacity and (ii) to evaluate the performance of a selected mutant strain in commercial-sized (125 000 L) open ponds in the north of Chile. Haematococcus pluvialis strain 114 was mutated by ethyl methanesulfonate. The level of mutagen dose (exposure time and concentration) was one that induced at least 90 % mortality. Surviving colonies were screened for resistance to the carotenoid biosynthesis inhibitor diphenylamine (25 µM). Resistant mutants were grown in a 30-mL volume for 30 days, after which the total carotenoid content was determined by spectrophotometry. Tens of mutants with improved carotenogenic capacity compared with the wild-type strain were isolated by the application of these standardized protocols. Some mutants exhibited curious morphological features such as spontaneous release of astaxanthin and loss of flagella. One of the mutants was grown outdoors in commercial-sized open ponds of 125 000 L in the north of Chile. Grown under similar conditions, the mutant strain accumulated 30 % more astaxanthin than the wild-type strain on a per dry weight basis and 72 % more on a per culture volume basis. We show that random mutagenesis/selection is an effective strategy for genetically improving strains of H. pluvialis and that improved carotenogenic capacity is maintained when the volume of the cultures is scaled up to a commercial size.

  20. Effects of temperature on the astaxanthin productivity and light harvesting characteristics of the green alga Haematococcus pluvialis.

    PubMed

    Giannelli, Luca; Yamada, Hiroyuki; Katsuda, Tomohisa; Yamaji, Hideki

    2015-03-01

    The green alga Haematococcus pluvialis, which accumulates astaxanthin at an optimal temperature of 20°C, was cultivated under temperatures of 20°C, 23.5°C, 27°C, and 30.5°C, in order to assess the effects on algal metabolism during the growth phase. The culture growth rate declined with above-optimal increases in temperature, and the final maximum cell concentration at 30.5°C reached only 35% of that attained at 20°C. On the contrary, the biomass productivity was increased under all the high-temperature conditions, probably reflecting the metabolism switch from cell duplication to energy accumulation that is typically observed in algal cultures subjected to environmental stress. Moreover, an increase in the light-harvesting capability of the alga was observed by means of the total pigment balance and the photosynthesis-intensity (PI) curve measured under the different cultivation conditions. Cultures kept at higher temperatures were able to better harvest and utilize the impinging light due to photo-acclimation. Finally, the differences in the astaxanthin metabolism were elucidated by subjecting the cultures to nitrogen starvation at 20°C and 27°C. In the culture at 27°C, a 1.4-fold increase in the astaxanthin productivity was observed when compared to that at 20°C, and the latter required almost two-fold more energy for the astaxanthin production compared with the 27°C culture.

  1. Comparative analysis of the outdoor culture of Haematococcus pluvialis in tubular and bubble column photobioreactors.

    PubMed

    López, M C García-Malea; Sánchez, E Del Río; López, J L Casas; Fernández, F G Acién; Sevilla, J M Fernández; Rivas, J; Guerrero, M G; Grima, E Molina

    2006-05-29

    The present paper makes a comparative analysis of the outdoor culture of H. pluvialis in a tubular photobioreactor and a bubble column. Both reactors had the same volume and were operated in the same way, thus allowing the influence of the reactor design to be analyzed. Due to the large changes in cell morphology and biochemical composition of H. pluvialis during outdoor culture, a new, faster methodology has been developed for their evaluation. Characterisation of the cultures is carried out on a macroscopic scale using a colorimetric method that allows the simultaneous determination of biomass concentration, and the chlorophyll, carotenoid and astaxanthin content of the biomass. On the microscopic scale, a method was developed based on the computer analysis of digital microscopic images. This method allows the quantification of cell population, average cell size and population homogeneity. The accuracy of the methods was verified during the operation of outdoor photobioreactors on a pilot plant scale. Data from the reactors showed tubular reactors to be more suitable for the production of H. pluvialis biomass and/or astaxanthin, due to their higher light availability. In the tubular photobioreactor biomass concentrations of 7.0 g/L (d.wt.) were reached after 16 days, with an overall biomass productivity of 0.41 g/L day. In the bubble column photobioreactor, on the other hand, the maximum biomass concentration reached was 1.4 g/L, with an overall biomass productivity of 0.06 g/L day. The maximum daily biomass productivity, 0.55 g/L day, was reached in the tubular photobioreactor for an average irradiance inside the culture of 130 microE/m2s. In addition, the carotenoid content of biomass from tubular photobioreactor increased up to 2.0%d.wt., whereas that of the biomass from the bubble column remained roughly constant at values of 0.5%d.wt. It should be noted that in the tubular photobioreactor under conditions of nitrate saturation, there was an accumulation of

  2. Cellular Capacities for High-Light Acclimation and Changing Lipid Profiles across Life Cycle Stages of the Green Alga Haematococcus pluvialis

    PubMed Central

    Wang, Baobei; Zhang, Zhen; Hu, Qiang; Sommerfeld, Milton; Lu, Yinghua; Han, Danxiang

    2014-01-01

    The unicellular microalga Haematococcus pluvialis has emerged as a promising biomass feedstock for the ketocarotenoid astaxanthin and neutral lipid triacylglycerol. Motile flagellates, resting palmella cells, and cysts are the major life cycle stages of H. pluvialis. Fast-growing motile cells are usually used to induce astaxanthin and triacylglycerol biosynthesis under stress conditions (high light or nutrient starvation); however, productivity of biomass and bioproducts are compromised due to the susceptibility of motile cells to stress. This study revealed that the Photosystem II (PSII) reaction center D1 protein, the manganese-stabilizing protein PsbO, and several major membrane glycerolipids (particularly for chloroplast membrane lipids monogalactosyldiacylglycerol and phosphatidylglycerol), decreased dramatically in motile cells under high light (HL). In contrast, palmella cells, which are transformed from motile cells after an extended period of time under favorable growth conditions, have developed multiple protective mechanisms—including reduction in chloroplast membrane lipids content, downplay of linear photosynthetic electron transport, and activating nonphotochemical quenching mechanisms—while accumulating triacylglycerol. Consequently, the membrane lipids and PSII proteins (D1 and PsbO) remained relatively stable in palmella cells subjected to HL. Introducing palmella instead of motile cells to stress conditions may greatly increase astaxanthin and lipid production in H. pluvialis culture. PMID:25221928

  3. Effect of red cyst cell inoculation and iron(II) supplementation on autotrophic astaxanthin production by Haematococcus pluvialis under outdoor summer conditions.

    PubMed

    Hong, Min-Eui; Choi, Yoon Young; Sim, Sang Jun

    2016-01-20

    The negative effect of heat stress on the autotrophic astaxanthin production by Haematococcus pluvialis has been observed during outdoor culture in summer. Under the summer conditions, the proliferation of vegetative cells was highly halted in the green stage and the inducibility in the biosynthesis of astaxanthin was partly hindered in the red stage. Herein, under outdoor summer conditions in which variations of the diurnal temperature occur, heat-stress-driven inefficient vegetative growth of H. pluvialis was highly improved by inoculating the red cyst cells; thereby, maintaining relatively moderate intracellular carotenoid levels in the green stage. Subsequently, a remarkably enhanced astaxanthin titer was successfully obtained by supplementing 50 μM iron(II) to induce the heat stress-driven Haber-Weiss reaction in the red stage. As a result, the productivity of astaxanthin in the cells cultured under summer temperature conditions (23.4-33.5 °C) using the two methods of red cell (cyst) inoculation and the iron(Fe(2+)) supplementation was increased by 147% up to 5.53 mg/L day compared with that of the cells cultured under spring temperature conditions (17.5-27.3 °C). Our technical solutions will definitely improve the annual natural astaxanthin productivity in H. pluvialis in locations confronted by hot summer weather, particularly in large-scale closed photobioreactor systems.

  4. Cellular capacities for high-light acclimation and changing lipid profiles across life cycle stages of the green alga Haematococcus pluvialis.

    PubMed

    Wang, Baobei; Zhang, Zhen; Hu, Qiang; Sommerfeld, Milton; Lu, Yinghua; Han, Danxiang

    2014-01-01

    The unicellular microalga Haematococcus pluvialis has emerged as a promising biomass feedstock for the ketocarotenoid astaxanthin and neutral lipid triacylglycerol. Motile flagellates, resting palmella cells, and cysts are the major life cycle stages of H. pluvialis. Fast-growing motile cells are usually used to induce astaxanthin and triacylglycerol biosynthesis under stress conditions (high light or nutrient starvation); however, productivity of biomass and bioproducts are compromised due to the susceptibility of motile cells to stress. This study revealed that the Photosystem II (PSII) reaction center D1 protein, the manganese-stabilizing protein PsbO, and several major membrane glycerolipids (particularly for chloroplast membrane lipids monogalactosyldiacylglycerol and phosphatidylglycerol), decreased dramatically in motile cells under high light (HL). In contrast, palmella cells, which are transformed from motile cells after an extended period of time under favorable growth conditions, have developed multiple protective mechanisms--including reduction in chloroplast membrane lipids content, downplay of linear photosynthetic electron transport, and activating nonphotochemical quenching mechanisms--while accumulating triacylglycerol. Consequently, the membrane lipids and PSII proteins (D1 and PsbO) remained relatively stable in palmella cells subjected to HL. Introducing palmella instead of motile cells to stress conditions may greatly increase astaxanthin and lipid production in H. pluvialis culture.

  5. Comparison of different cells of Haematococcus pluvialis reveals an extensive acclimation mechanism during its aging process: from a perspective of photosynthesis.

    PubMed

    Gu, Wenhui; Xie, Xiujun; Gao, Shan; Zhou, Wei; Pan, Guanghua; Wang, Guangce

    2013-01-01

    Both biomass dominated green vegetative cells (GV) and astaxanthin-dominated orange resting cells (OR) affect the final astaxanthin yield in industry. Examination of Haematococcus pluvialis revealed that the OR cells greatly varied from the GV cells at both cellular and subcellular levels. In particular, the thylakoid membranes in the OR were disassembled and fragmented. Furthermore, the OR conserved most of the photosynthetic pigments, with elevated concentrations of violaxanthin, antheraxanthin, and neoxanthin. Notably, moderate photosynthesis was detected in OR, even though most of the thylakoid membranes were disassembled, when compared with those in the GV. However, the energy distribution pattern between photosystem I and II (PSI and PSII) in the OR favored PSI, which was also confirmed by 77-K fluorescence. As zeaxanthin was not detected in the OR, we attribute the acclimation role to astaxanthin, instead of xanthophyll cycle. Additionally, proteomic-scale comparison analysis of thylakoids of the OR and GV indicated no photosynthetically remarkable variations. However, an extensive acclimation mechanism of H. pluvialis was proposed, in which proteins in thylakoid of GV were noted to be involved in biomass accumulation and those in OR were involved in stress response. Conclusions of the comparative analysis might provide some physiological background of OR for astaxanthin production by using H. pluvialis.

  6. Expression of bkt and bch genes from Haematococcus pluvialis in transgenic Chlamydomonas.

    PubMed

    Zheng, KaiJing; Wang, ChaoGang; Xiao, Ming; Chen, Jun; Li, JianCheng; Hu, ZhangLi

    2014-10-01

    β-carotene ketolase and β-carotene hydroxylase encoded by bkt and bch, respectively, are key enzymes required for astaxanthin biosynthesis in Haematococcu pluvialis 34-1n. Two expression vectors containing cDNA sequences of bkt and bch were constructed and co-transformed into cell-wall-deficient Chlamydomonas reinhardtii CC-849. Transgenic algae were screened on TAP agar plates containing 10 μg mL(-1) Zeomycin. PCR-Southern analysis showed that bkt and bch were integrated into the genomes of C. reinhardtii. Transcripts of bkt and bch were further confirmed by RT-PCR-Southern analysis. Compared with the wild type, transgenic algae produced 29.04% and 30.27% more carotenoids and xanthophylls, respectively. Moreover, the transgenic algae could accumulate 34% more astaxanthin than wild type. These results indicate that foreign bkt and bch genes were successfully translated into β-carotene ketolase and β-carotene hydroxylase, which were responsible for catalyzing the biosynthesis of astaxanthin in transgenic algae.

  7. Sodiation as a tool for enhancing the diagnostic value of MALDI-TOF/TOF-MS spectra of complex astaxanthin ester mixtures from Haematococcus pluvialis.

    PubMed

    Weesepoel, Yannick; Vincken, Jean-Paul; Pop, Raluca Maria; Liu, Kun; Gruppen, Harry

    2013-07-01

    The microalga Haematococcus pluvialis produces the pigment astaxanthin mainly in esterified form with a multitude of fatty acids, which results in a complex mixture of carotenol mono- and diesters. For rapid fingerprinting of these esters, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF/TOF-MS) might be an alternative to traditional chromatographic separation combined with MS. Investigation of ionization and fragmentation of astaxanthin mono- and diester palmitate standards in MALDI-TOF/TOF-MS showed that sodium adduct parent masses [M + Na](+) gave much simpler MS(2) spectra than radical / protonated [M](+●) / [M + H](+) parents. [M + Na](+) fragments yielded diagnostic polyene-specific eliminations and fatty acid neutral losses, whereas [M](+●) / [M + H](+) fragmentation resulted in a multitude of non-diagnostic daughters. For diesters, a benzonium fragment, formed by polyene elimination, was required for identification of the second fatty acid attached to the astaxanthin backbone. Parents were forced into [M + Na](+) ionization by addition of sodium acetate, and best signal-to-noise ratios were obtained in the 0.1 to 1.0 mM range. This method was applied to fingerprinting astaxanthin esters in a crude H. pluvialis extract. Prior to MALDI-TOF/TOF-MS, the extract was fractionated by normal phase Flash chromatography to obtain fractions enriched in mono- and diesters and to remove pheophytin a, which compromised monoester signals. All 12 types of all-trans esterified esters found in LC were identified with MALDI-TOF/TOF-MS, with the exception of two minor monoesters.

  8. Investigation of the maximum quantum yield of PS II in Haematococcus pluvialis cell cultures during growth: effects of chemical or high-intensity light treatment.

    PubMed

    Wang, Hui-Chih; Cho, Man-Gi; Riznichenko, Galina; Rubin, Andrey B; Lee, Ji-Hyun

    2011-09-02

    In this study, we investigated the increase in photosynthetic quantum yield that occurs in advance of increased microalgal growth. Haematococcus pluvialis was cultivated under normal conditions; the number of cells, the maximum quantum yield of photosystem II (F(v)/F(m)), and optical density were measured. We observed an increase in F(v)/F(m) approximately 72h prior to the cell growth phase. To confirm the relationship between photosynthetic yield and growth, samples were treated with several chemicals under high-intensity light illumination and control conditions to inhibit photosystem II and induce a decrease in the quantum photosynthetic yield. The samples were exposed to high-intensity light at an irradiance of 400μmol photonsm(-2)s(-1) for varied amount of time and were treated with chemicals such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea, nigericin sodium salt and valinomycin. We observed that both the photooxidation of photosystem II reaction centers and the formation of transmembrane electrochemical gradients led to an initial decrease in fluorescence yield after the onset of high-intensity light illumination. We also observed that treatment of high-intensity light illuminated cells with antibiotics after adaptation to moderate light intensities caused a difference in photosynthetic activity. In conclusion, the maximum quantum yield of photosystem II is obtained prior to the cell growth phase and can therefore be used as a prediction parameter for cell growth. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Enriched Astaxanthin Extract from Haematococcus pluvialis Augments Growth Factor Secretions to Increase Cell Proliferation and Induces MMP1 Degradation to Enhance Collagen Production in Human Dermal Fibroblasts.

    PubMed

    Chou, Hsin-Yu; Lee, Chelsea; Pan, Jian-Liang; Wen, Zhi-Hong; Huang, Shu-Hung; Lan, Chi-Wei John; Liu, Wang-Ta; Hour, Tzyh-Chyuan; Hseu, You-Cheng; Hwang, Byeong Hee; Cheng, Kuo-Chen; Wang, Hui-Min David

    2016-06-16

    Among many antioxidants that are used for the repairing of oxidative stress induced skin damages, we identified the enriched astaxanthin extract (EAE) from Haematococcus pluvialis as a viable ingredient. EAE was extracted from the red microalgae through supercritical fluid carbon dioxide extraction. To compare the effectiveness, EAE wastreated on human dermal fibroblasts with other components, phorbol 12-myristate 13-acetate (PMA), and doxycycline. With sirius red staining and quantitative real-time polymerase chain reaction (qRT-PCR), we found that PMA decreased the collagen concentration and production while overall the addition of doxycycline and EAE increased the collagen concentration in a trial experiments. EAE increased collagen contents through inhibited MMP1 and MMP3 mRNA expression and induced TIMP1, the antagonists of MMPs protein, gene expression. As for when tested for various proteins through western blotting, it was seen that the addition of EAE increased the expression of certain proteins that promote cell proliferation. Testing those previous solutions using growth factor assay, it was noticeable that EAE had a positive impact on cell proliferation and vascular endothelial growth factor (VEGF) than doxycycline, indicating that it was a better alternative treatment for collagen production. To sum up, the data confirmed the possible applications as medical cosmetology agentsand food supplements.

  10. Analysis of mRNA expression profiles of carotenogenesis and astaxanthin production of Haematococcus pluvialis under exogenous 2, 4-epibrassinolide (EBR).

    PubMed

    Gao, Zhengquan; Meng, Chunxiao; Gao, Hongzheng; Zhang, Xiaowen; Xu, Dong; Su, Yuanfeng; Wang, Yuanyuan; Zhao, Yuren; Ye, Naihao

    2013-01-01

    The fresh-water green unicellular alga Haematococcus pluvialis is known to accumulate astaxanthin under stress conditions. In the present study, transcriptional expression of eight genes involved in astaxanthin biosynthesis exposed to EBR (25 and 50 mg/L) was analyzed using qRT-PCR. The results demonstrated that both 25 and 50 mg/L EBR could increase astaxanthin productivity and the eight carotenogenic genes were up-regulated by EBR with different expression profiles. Moreover, EBR25 induction had a greater influence on the transcriptional expression of ipi-1, ipi-2, crtR-B, lyc and crtO (> 5- fold up-regulation) than on psy, pds, bkt; EBR50 treatment had a greater effect on the transcriptional expression of ipi-2, pds, lyc, crtR-B, bkt and crtO than on ipi-1 and psy. Furthermore, astaxanthin biosynthesis under EBR was up-regulated mainly by ipi1־ and psy at the post-transcriptional level, pds, lyc, crtR-B, bkt and crtO at the transcriptional level and ipi-2 at both levels.

  11. Enriched Astaxanthin Extract from Haematococcus pluvialis Augments Growth Factor Secretions to Increase Cell Proliferation and Induces MMP1 Degradation to Enhance Collagen Production in Human Dermal Fibroblasts

    PubMed Central

    Chou, Hsin-Yu; Lee, Chelsea; Pan, Jian-Liang; Wen, Zhi-Hong; Huang, Shu-Hung; Lan, Chi-Wei John; Liu, Wang-Ta; Hour, Tzyh-Chyuan; Hseu, You-Cheng; Hwang, Byeong Hee; Cheng, Kuo-Chen; Wang, Hui-Min David

    2016-01-01

    Among many antioxidants that are used for the repairing of oxidative stress induced skin damages, we identified the enriched astaxanthin extract (EAE) from Haematococcus pluvialis as a viable ingredient. EAE was extracted from the red microalgae through supercritical fluid carbon dioxide extraction. To compare the effectiveness, EAE wastreated on human dermal fibroblasts with other components, phorbol 12-myristate 13-acetate (PMA), and doxycycline. With sirius red staining and quantitative real-time polymerase chain reaction (qRT-PCR), we found that PMA decreased the collagen concentration and production while overall the addition of doxycycline and EAE increased the collagen concentration in a trial experiments. EAE increased collagen contents through inhibited MMP1 and MMP3 mRNA expression and induced TIMP1, the antagonists of MMPs protein, gene expression. As for when tested for various proteins through western blotting, it was seen that the addition of EAE increased the expression of certain proteins that promote cell proliferation. Testing those previous solutions using growth factor assay, it was noticeable that EAE had a positive impact on cell proliferation and vascular endothelial growth factor (VEGF) than doxycycline, indicating that it was a better alternative treatment for collagen production. To sum up, the data confirmed the possible applications as medical cosmetology agentsand food supplements. PMID:27322248

  12. Simultaneous determination of 13 carotenoids by a simple C18 column-based ultra-high-pressure liquid chromatography method for carotenoid profiling in the astaxanthin-accumulating Haematococcus pluvialis.

    PubMed

    Jin, Hui; Lao, Yong Min; Zhou, Jin; Zhang, Huai Jin; Cai, Zhong Hua

    2017-03-10

    A simple ultra-high-pressure liquid chromatography (UHPLC) method for rapidly and simultaneously identifying thirteen carotenoids in Haematococcus pluvialis was developed in this study. The method is capable of effectively separating two astaxanthin isomers, two ζ-carotene isomers, and three phytoene isomers on two simple C18 columns within 9 and 12min only by using methanol and acetonitrile, respectively. To our best knowledge, this is the rapidest method for these carotenoid isomers, currently. Using this method, carotenoid profiling in the astaxanthin-accumulating H. pluvialis under environmental stresses was successfully carried out. Results indicated that carotenoid biosynthesis was differentially perturbed by environmental stresses, indicating that this simple and rapid method is suitable to not only bacterial but also algal samples, with potential applications for a wide range of samples from plant to animal. Finally, possible reasons for the elution order of carotenoids were studied.

  13. Metabolite Profiling and Integrative Modeling Reveal Metabolic Constraints for Carbon Partitioning under Nitrogen Starvation in the Green Algae Haematococcus pluvialis*

    PubMed Central

    Recht, Lee; Töpfer, Nadine; Batushansky, Albert; Sikron, Noga; Gibon, Yves; Fait, Aaron; Nikoloski, Zoran; Boussiba, Sammy; Zarka, Aliza

    2014-01-01

    The green alga Hematococcus pluvialis accumulates large amounts of the antioxidant astaxanthin under inductive stress conditions, such as nitrogen starvation. The response to nitrogen starvation and high light leads to the accumulation of carbohydrates and fatty acids as well as increased activity of the tricarboxylic acid cycle. Although the behavior of individual pathways has been well investigated, little is known about the systemic effects of the stress response mechanism. Here we present time-resolved metabolite, enzyme activity, and physiological data that capture the metabolic response of H. pluvialis under nitrogen starvation and high light. The data were integrated into a putative genome-scale model of the green alga to in silico test hypotheses of underlying carbon partitioning. The model-based hypothesis testing reinforces the involvement of starch degradation to support fatty acid synthesis in the later stages of the stress response. In addition, our findings support a possible mechanism for the involvement of the increased activity of the tricarboxylic acid cycle in carbon repartitioning. Finally, the in vitro experiments and the in silico modeling presented here emphasize the predictive power of large scale integrative approaches to pinpoint metabolic adjustment to changing environments. PMID:25183014

  14. Metabolite profiling and integrative modeling reveal metabolic constraints for carbon partitioning under nitrogen starvation in the green algae Haematococcus pluvialis.

    PubMed

    Recht, Lee; Töpfer, Nadine; Batushansky, Albert; Sikron, Noga; Gibon, Yves; Fait, Aaron; Nikoloski, Zoran; Boussiba, Sammy; Zarka, Aliza

    2014-10-31

    The green alga Hematococcus pluvialis accumulates large amounts of the antioxidant astaxanthin under inductive stress conditions, such as nitrogen starvation. The response to nitrogen starvation and high light leads to the accumulation of carbohydrates and fatty acids as well as increased activity of the tricarboxylic acid cycle. Although the behavior of individual pathways has been well investigated, little is known about the systemic effects of the stress response mechanism. Here we present time-resolved metabolite, enzyme activity, and physiological data that capture the metabolic response of H. pluvialis under nitrogen starvation and high light. The data were integrated into a putative genome-scale model of the green alga to in silico test hypotheses of underlying carbon partitioning. The model-based hypothesis testing reinforces the involvement of starch degradation to support fatty acid synthesis in the later stages of the stress response. In addition, our findings support a possible mechanism for the involvement of the increased activity of the tricarboxylic acid cycle in carbon repartitioning. Finally, the in vitro experiments and the in silico modeling presented here emphasize the predictive power of large scale integrative approaches to pinpoint metabolic adjustment to changing environments.

  15. Effects of postexercise feeding of a supplemental carbohydrate and protein bar with or without astaxanthin from Haematococcus pluvialis to exercise-conditioned dogs.

    PubMed

    Zanghi, Brian M; Middleton, Rondo P; Reynolds, Arleigh J

    2015-04-01

    To characterize the postprandial nutrient profiles of exercise-conditioned dogs fed a supplemental carbohydrate and protein bar with or without astaxanthin from Haematococcus pluvialis immediately after exercise. 34 exercise-conditioned adult Husky-Pointer dogs. The study had 2 phases. During phase 1, postprandial plasma glucose concentration was determined for dogs fed a bar containing 25% protein and 18.5% or 37.4% maltodextrin plus dextrin (rapidly digestible carbohydrate; RDC), or dry kibble (30% protein and 0% RDC) immediately after exercise. During phase 2, dogs were exercised for 3 days and fed a bar (25% protein and 37.4% RDC) with (CPA; n = 8) or without (CP; 8) astaxanthin or no bar (control; 8) immediately after exercise. Pre- and postexercise concentrations of plasma biochemical analytes and serum amino acids were determined on days 1 and 3. Phase 1 postexercise glucose concentration was increased when dogs were provided the 37.4% RDC bar, but not 0% or 18.5% RDC. On day 3 of phase 2, the CPA group had the highest pre-exercise triglyceride concentration and significantly less decline in postexercise glucose concentration than did the CP and control groups. Mean glucose concentration for the CP and CPA groups was significantly higher than that for the control group between 15 and 60 minutes after bar consumption. Compared to immediately after exercise, branched-chain amino acid, tryptophan, leucine, and threonine concentrations 15 minutes after exercise were significantly higher for the CP and CPA groups, but were lower for the control group. Dogs fed a bar with 37.4% RDCs and 25% protein immediately after exercise had increased blood nutrient concentrations for glycogen and protein synthesis, compared with control dogs.

  16. Effect of the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid on different growth stages of Haematococcus pluvialis.

    PubMed

    Vo, Thi-Thao; Lee, Changsu; Han, Sang-Il; Kim, Jee Young; Kim, Sok; Choi, Yoon-E

    2016-11-01

    In this study, we explored the effects of ACC on other stages of H. pluvialis. Interestingly, even though ACC displayed a dose-dependent effect on astaxanthin production, it is evident that astaxanthin production could be facilitated whenever the cells were treated at the early red stage. The transcriptional levels of BKT, CHY, SOD, and CAT genes supported enhanced astaxanthin biosynthesis upon ACC treatment at the early red stage. The combinatorial synergistic effect of ACC and light intensity was also confirmed. Finally, two-step application of ACC at the vegetative phase to increase biomass production and at the early-red stage to promote astaxanthin biosynthesis was proposed to maximize the efficiency of ACC treatment.

  17. The chlorophyll a fluorescence induction curve in the green microalga Haematococcus pluvialis: further insight into the nature of the P-S-M fluctuation and its relationship with the "low-wave" phenomenon at steady-state.

    PubMed

    Fratamico, Anthony; Tocquin, Pierre; Franck, Fabrice

    2016-06-01

    Chlorophyll fluorescence is an information-rich signal which provides an access to the management of light absorbed by PSII. A good example of this is the succession of fast fluorescence fluctuations during light-induced photosynthetic induction after dark-adaptation. During this period, the fluorescence trace exhibits several inflexion points: O-J-I-P-S-M-T. Whereas the OJIP part of this kinetics has been the subject of many studies, the processes that underly the PSMT transient are less understood. Here, we report an analysis of the PSMT phase in the green microalga Haematococcus pluvialis in terms of electron acceptors and light use by photochemistry, fluorescence and non-photochemical quenching (NPQ). We identify additional sub-phases between P and S delimited by an inflexion point, that we name Q, found in the second time scale. The P-Q phase expresses a transient photochemical quenching specifically due to alternative electron transport to oxygen. During the transition from Q to S, the NPQ increases and then relaxes during the S-M phase in about 1 min. It is suggested that this transient NPQ observed during induction is a high energy state quenching (qE) dependent on the alternative electron transport to molecular oxygen. We further show that this NPQ is of the same nature than the NPQ, known as the low-wave phenomenon, which is transiently observed after a saturating light pulse given at steady-state. In both cases, the NPQ is oxygen-dependent. This NPQ is observed at external pH 6.0, but not at pH 7.5, which seems correlated with faster saturation of the PQ pool at pH 6.0.

  18. Assessing contamination of microalgal astaxanthin producer Haematococcus cultures with high-resolution melting curve analysis.

    PubMed

    Dawidziuk, Adam; Popiel, Delfina; Luboinska, Magda; Grzebyk, Michal; Wisniewski, Maciej; Koczyk, Grzegorz

    2016-11-26

    Due to its superior antioxidant capabilities and higher activity than other carotenoids, astaxanthin is used widely in the nutraceutical and medicine industries. The most prolific natural producer of astaxanthin is the unicellular green microalga Haematococcus pluvialis. The correct identification of any contaminants in H. pluvialis cultures is both essential and nontrivial for several reasons. Firstly, while it is possible to distinguish the main microalgal contaminant Coelastrella sp. (in H. pluvialis cultures), in practice, it is frequently a daunting and error-prone task for personnel without extensive experience in the microscopic identification of algal species. Secondly, the undetected contaminants may decrease or stop production of astaxanthin. Lastly, the presence of other contaminants such as fungi can eventually infect and destroy the whole algae collection. In this study, high-resolution melting (HRM) analysis was developed to detect microalgal and fungal contamination. The developed diagnostic procedure allowed to distinguish pure H. pluvialis samples from cultures contaminated with low amounts (1.25 ng/ml) of microalgal DNA and fungal DNA (2.5 ng/ml). Such discrimination is not possible with the use of microscopy observations and allows fast and efficient collection testing.

  19. Some Physical Parameters to Effect the Production of Heamatococcus pluvialis

    NASA Astrophysics Data System (ADS)

    Akpolat, O.; Eristurk, S.

    The aim of this study is to optimize the physical parameters affecting the production of Haematococcus pluvialis in photobioreactors and to simulate the process. Heamatococcus pluvialis is a green microalgea to have a great interest for production of natural astaxanthin and it can be cultivated in a closed photobiorector system under controlled conditions. Biomass composition, growth rate and high value product spectra like polyunsaturated fatty acids, pigments, poly saccariydes or vitamins depend on strongly the parameters of cultivation process. These are composition of cultivation medium, mixing model and aeration rate, hydrodynamic stress of medium which can be changed by adding some chemicals, cultivation temperature, pH, carbon dioxide and oxygen supply and most important of all: illumination. One of the most important problems during the cultivation is that cells have sensitivity to shear stress very much and the shear stress created by aeration and mixing effects the growth rate of the cell negatively and decreases yield. In this study, physical parameters such as; the rate of the air fed into the reactor, the mixing type, the reduction of the hydrodynamic stress by CMC addition, the effect of the cell size on the cell production and the flocculation speed of the culture, were investigated.

  20. Microencapsulation of H. pluvialis oleoresins with different fatty acid composition: Kinetic stability of astaxanthin and alpha-tocopherol.

    PubMed

    Bustamante, Andrés; Masson, Lilia; Velasco, Joaquín; del Valle, José Manuel; Robert, Paz

    2016-01-01

    Haematococcus pluvialis is a natural source of astaxanthin (AX). However, AX loses its natural protection when extracted from this microalga. In this study, a supercritical fluid extract (SFE) of H. pluvialis was obtained and added to oils with different fatty acid compositions (sunflower oil (SO) or high oleic sunflower oil (HOSO)). The oleoresins of H. pluvialis ((SO+SFE) and (HOSO+SFE)) were encapsulated with Capsul by spray drying. The stability of the oleoresins and powders were studied at 40, 50 and 70° C. AX and alpha-tocopherol (AT) degradation followed a zero-order and first-order kinetic model, respectively, for all systems. The encapsulation of oleoresins improved the stability of AX and AT to a greater extent in oleoresins with a monounsaturated fatty acid profile, as shown by the significantly lowest degradation rate constants and longest half-lives. Therefore, the encapsulation of H. pluvialis oleoresins is an alternative to developing a functional ingredient for healthy food design.

  1. A Combination of Soybean and Haematococcus Extract Alleviates Ultraviolet B-Induced Photoaging

    PubMed Central

    Shin, Jieun; Kim, Jong-Eun; Pak, Kum-Ju; Kang, Jung Il; Kim, Tae-Seok; Lee, Sang-Yoon; Yeo, Ik-Hyun; Park, Jung Han Yoon; Kim, Jong Hun; Kang, Nam Joo; Lee, Ki Won

    2017-01-01

    Soybean-derived isoflavones have been investigated for their preventative effects against UV-induced symptoms of skin damage including wrinkle formation and inflammation. Haematococcus pluvialis is a freshwater species of Chlorophyta that contains high concentrations of the natural carotenoid pigment astaxanthin. Astaxanthin is known to be involved in retinoic acid receptor (RAR) signaling and previously been associated with the inhibition of activator protein (AP)-1 dependent transcription. Based on previous studies, we hypothesized that a combination of soy extract (SE) and Haematococcus extract (HE) may prevent UVB-induced photoaging through specific signaling pathways, as measured by UVB-induced wrinkling on hairless mice skin and expression changes in human dermal fibroblasts (HDFs). The 1:2 ratio of SE and HE mixture (SHM) showed the optimal benefit in vivo. SHM was found to inhibit wrinkle formation via the downregulation of matrix metalloproteinase (MMP)-1 mRNA and protein expression. SHM also inhibited mitogen-activated protein kinase (MAPK) phosphorylation and the transactivation of AP-1 which plays an important role in regulating MMP expression. These results highlight the potential for SHM to be developed as a therapeutic agent to prevent UVB-induced skin wrinkling. PMID:28327532

  2. In vivo hyperspectral CARS and FWM microscopy of carotenoid accumulation in H. Pluvialis

    NASA Astrophysics Data System (ADS)

    Slepkov, Aaron D.; Barlow, Aaron M.; Ridsdale, Andrew; McGinn, Patrick J.; Stolow, Albert

    2014-02-01

    Coherent anti-Stokes Raman scattering (CARS) and four-wave-mixing (FWM) microscopy are a related pair of powerful nonlinear optical characterization tools. These techniques often yield strong signals from concentrated samples, but because of their quadratic dependence on concentration, they are not typically employed for imaging or identifying dilute cellular constituents. We report here that, depending on the excitation wavelengths employed, both CARS and degenerate-FWM signals from carotenoid accumulations in alga cysts can be exceptionally large, allowing for low-power imaging of astaxanthin (AXN) deposits in Haematococcus pluvialis microalga. By use of a broadband laser pulse scheme for CARS and FWM, we are able to simultaneously collect strong intrinsic two-photon-excitation fluorescence signals from cellular chlorophyll in vivo. We show that CARS signals from astaxanthin (AXN) samples in vitro strictly follow the expected quadratic dependence on concentration, and we demonstrate the collection of wellresolved CARS spectra in the fingerprint region with sensitivity below 2mM. We suggest that multimodal nonlinear optical microscopy is sufficiently sensitive to AXN and chlorophyll concentrations that it will allow for non-invasive monitoring of carotenogenesis in live H. pluvialis microalgae.

  3. Survival of Chlorophyceae Ingested by Saprozoic Nematodes

    PubMed Central

    Leake, P. A.; Jensen, H. J.

    1970-01-01

    The saprozoic nematode, Pristionchus lheritieri ingested cells of four species of unicellular Chlorophyceae (grass-green algae) including Chlamydomonas reinhardi and unidentified species of Ankistrodesmus, Chlamydornonas and Scenedesmus. Additional tests with Ankistrodesmus sp. and Chlamydomonas sp., indicated cells of Ankistrodesmus survived passage through the alimentary canal and were subsequently cultured, while viable cells of Chlarnydomonas were only occasionally recovered. PMID:19322324

  4. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  5. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  6. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  7. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  8. 21 CFR 73.185 - Haematococcus algae meal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  9. Astaxanthin preparation by fermentation of esters from Haematococcus pluvialis algal extracts with Stenotrophomonas species.

    PubMed

    Dong, Hao; Li, Xuemin; Xue, Changhu; Mao, Xiangzhao

    2016-05-01

    Natural astaxanthin (Ax) is an additive that is widely used because of its beneficial biochemical functions. However, the methods used to produce free Ax have drawbacks. Chemical saponification methods produce several by-products, and lipase-catalyzed hydrolysis methods are not cost effective. In this study, a bacterial strain of Stenotrophomonas sp. was selected to enzymatically catalyze the saponification of Ax esters to produce free all-trans-Ax. Through single-factor experiments and a Box-Behnken design, the optimal fermentation conditions were determined as follows: a seed culture age of 37.79 h, an inoculum concentration of 5.92%, and an initial broth pH of 6.80. Under these conditions, a fermentation curve was drawn, and the optimal fermentation time was shown to be 60 h. At 60 h, the degradation rate of the Ax esters was 98.08%, and the yield of free all-trans-Ax was 50.130 μg/mL. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:649-656, 2016. © 2016 American Institute of Chemical Engineers.

  10. Differential Expression of Carotenogenic Genes, Associated Changes on Astaxanthin Production and Photosynthesis Features Induced by JA in H. pluvialis

    PubMed Central

    Zhang, Xiaowen; Xu, Dong; Zhao, Yuefeng; Wang, Yitao; Lv, Hongxin; Liming Yang; Chen, Lingling; Ye, Naihao

    2012-01-01

    Haematococcus pluvialis is an organism that under certain conditions can produce astaxanthin, an economically important carotenoid. In this study, the transcriptional expression patterns of eight carotenogenic genes of H. pluvialis in response to jasmonic acid (JA) were evaluated using real-time PCR. Astaxanthin accumulation action and photosynthesis flourescence were monitored at the same time. The results showed all eight genes exhibited higher transcriptional expression significantly under JA treatments. JA25 (25 mg/L) induction had greater effect (>10-fold up-regulation) on the transcriptional expression of pds, crtR-B and lyc than on ipi-1, ipi-2, psy, bkt2, and crtO. JA50 (50 mg/L) treatment had greater impact on the transcriptional expression of ipi-1, ipi-2, psy, crtR-B and crtO than on pds, lyc and bkt2. Astaxanthin biosynthesis in the presence of JA appeared to be up-regulated mainly by psy, pds, crtR-B, lyc, bkt2 and crtO at the transcriptional level and ipi-1, ipi-2 at both transcriptional and post-transcriptional levels. Under JA induction, the photosynthetic efficiency [Y (II)] and the maximum quantum efficiency of PS II (Fv/Fm) decreased significantly, but the non-photochemical quenching of chlorophyll fluorescence (NPQ) increased drastically with the accumulation of astaxanthin. PMID:22870309

  11. Astaxanthin induction in Microalga H. pluvialis with flat panel airlift photobioreactors under indoor and outdoor conditions.

    PubMed

    Poonkum, Woradej; Powtongsook, Sorawit; Pavasant, Prasert

    2015-01-01

    Astaxanthin was induced from Haematococcus pluvialis (NIES-144) under indoor and outdoor conditions using 17-, 50-, and 90-L flat-panel airlift photobioreactors (FP-APBRs). Preliminary experiments in 1.5-L bubble column photobioreactors (BC-PBRs) revealed that sterilized clean water with 3% CO2 aeration (1.47 cm(3) s(-1) CO2 loading) could best encourage astaxanthin accumulation at 18.21 g m(-3) (3.63% by weight). Operating 17-L FP-APBRs with these bubble column parameters under indoor conditions could further enhance astaxanthin to 26.63 g m(-3) (5.34% by weight). This was potentially due to the inherited up-lift force from the reactor that helped avoid cell precipitation by allowing the cells to be circulated within the reactor. In addition, the various sizes of FP-APBRs exhibited similar performance, implying a potential scale-up opportunity. However, similar operation under outdoor condition exhibited slightly poorer performance due to the light inhibition effect. The best outdoor performance was obtained with the FP-APBR covered with one layer of shading net, where 20.11 g m(-3) (4.47% by weight) of astaxanthin was resulted.

  12. Accurate quantification of astaxanthin from Haematococcus crude extract spectrophotometrically

    NASA Astrophysics Data System (ADS)

    Li, Yeguang; Miao, Fengping; Geng, Yahong; Lu, Dayan; Zhang, Chengwu; Zeng, Mingtao

    2012-07-01

    The influence of alkali on astaxanthin and the optimal working wave length for measurement of astaxanthin from Haematococcus crude extract were investigated, and a spectrophotometric method for precise quantification of the astaxanthin based on the method of Boussiba et al. was established. According to Boussiba's method, alkali treatment destroys chlorophyll. However, we found that: 1) carotenoid content declined for about 25% in Haematococcus fresh cysts and up to 30% in dry powder of Haematococcus broken cysts after alkali treatment; and 2) dimethyl sulfoxide (DMSO)-extracted chlorophyll of green Haematococcus bares little absorption at 520-550 nm. Interestingly, a good linear relationship existed between absorbance at 530 nm and astaxanthin content, while an unknown interference at 540-550 nm was detected in our study. Therefore, with 530 nm as working wavelength, the alkali treatment to destroy chlorophyll was not necessary and the influence of chlorophyll, other carotenoids, and the unknown interference could be avoided. The astaxanthin contents of two samples were measured at 492 nm and 530 nm; the measured values at 530 nm were 2.617 g/100 g and 1.811 g/100 g. When compared with the measured values at 492 nm, the measured values at 530 nm decreased by 6.93% and 11.96%, respectively. The measured values at 530 nm are closer to the true astaxanthin contents in the samples. The data show that 530 nm is the most suitable wave length for spectrophotometric determination to the astaxanthin in Haematococcus crude extract.

  13. Production of terpenes in the culture of Chlorophyceae and Rhodophyta

    NASA Astrophysics Data System (ADS)

    Abe, M.; Hashimoto, S.

    2014-12-01

    Terpenes show high reactivity in the troposphere, contributing to organic aerosol reactions with OH radicals. One of the main sources of terpenes in the atmosphere is terrestrial plants. It has been recently reported that marine phytoplankton also produce monoterpenes (Yassaa et al: 2008). Because aerosol production of natural origin affects the cloud cover over the open ocean, it is important to investigate the origin of aerosol generation in the open ocean. In this study, we investigated the production of terpenes and isoprene with a focus on Chlamydomonas (Chlorophyceae) and Rhodella maculata (Rhodophyta). Concentrations of terpenes and isoprene were measured using a dynamic headspace (GERSTEL DHS)—gas chromatograph (Agilent 6890N)—mass spectrometer (Agilent 5975C). In addition, chlorophyll a was measured using a fluorometer (Turner TD-700). The results showed that isoprene, α-pinene, and β-pinene were produced by Chlamydomonas sp. and that isoprene, limonene, and camphene were produced by Rhodella maculata. Chlamydomonas sp. produced α-pinene and β-pinene, similar to land plants. The ratio of the pinene/isoprene concentrations in the atmosphere over seawater where phytoplankton are blooming has been reported as approximately 0.7 (Yassaa et al: 2008). In this experiment, the pinene/isoprene concentration ratios in the cultures were approximately 0.1. This result indicates that marine phytoplankton may not be ignored in the marine atmosphere chemistry of terpenes.

  14. Phytophthora pluvialis, a new species from mixed tanoak-Douglas-fir forests of western Oregon, U.S.A

    Treesearch

    Paul Reeser; Wendy Sutton; Everett Hansen

    2013-01-01

    A new species, Phytophthora pluvialis is described. P. pluvialis has been recovered from streams, soil and canopy drip in the mixed tanoak-Douglas-fir forest in Curry County, Oregon, and in two additional streams in other areas of western Oregon. It has been found only rarely in association with twig and stem cankers on tanoak...

  15. Cell-wall disruption and lipid/astaxanthin extraction from microalgae: Chlorella and Haematococcus.

    PubMed

    Kim, Dong-Yeon; Vijayan, Durairaj; Praveenkumar, Ramasamy; Han, Jong-In; Lee, Kyubock; Park, Ji-Yeon; Chang, Won-Seok; Lee, Jin-Suk; Oh, You-Kwan

    2016-01-01

    Recently, biofuels and nutraceuticals produced from microalgae have emerged as major interests, resulting in intensive research of the microalgal biorefinery process. In this paper, recent developments in cell-wall disruption and extraction methods are reviewed, focusing on lipid and astaxanthin production from the biotechnologically important microalgae Chlorella and Haematococcus, respectively. As a common, critical bottleneck for recovery of intracellular components such as lipid and astaxanthin from these microalgae, the composition and structure of rigid, thick cell-walls were analyzed. Various chemical, physical, physico-chemical, and biological methods applied for cell-wall breakage and lipid/astaxanthin extraction from Chlorella and Haematococcus are discussed in detail and compared based on efficiency, energy consumption, type and dosage of solvent, biomass concentration and status (wet/dried), toxicity, scalability, and synergistic combinations. This report could serve as a useful guide to the implementation of practical downstream processes for recovery of valuable products from microalgae including Chlorella and Haematococcus.

  16. Growth and development time of subtropical Cladocera Diaphanosoma birgei Korinek, 1981 fed with different microalgal diets.

    PubMed

    Sipaúba-Tavares, L H; Truzzi, B S; Berchielli-Morais, F A

    2014-05-01

    The aim of this work was to investigate the growth performance of Diaphanosoma birgei fed with two Chlorophyceae algae, Ankistrodesmus gracilis and Haematococcus pluvialis using monoalgal diets and simpler mixed diets. D. birgei was daily fed on four treatments: 1) 100% Ankistrodesmus gracilis (Ag); 2) 100% Haematoccocus pluvialis (Hp); 3) 25% A. gracilis + 75% H. pluvialis (Ag-25+Hp-75) and 4) 75% A. gracilis + 25% H. pluvialis (Ag-75+Hp-25). The fecundity curve of D. birgei showed that the mixed feed Ag-25+Hp-75 and temperature 24±2°C triggered fast fecundity at approximately two days. The fecundity was low when based only on H. pluvialis (Hp), albeit with greater longevity (19 days) and a higher number of broods (8). D. birgei fed on Ag and Ag-75+Hp-25 diets in this experiment sustained higher growth rate and higher lipid content in these treatments. The present study showed that A. gracilis diet and mixed microalgae diets tested were able to support the egg production and development of D. birgei.

  17. Plastomes of the green algae Hydrodictyon reticulatum and Pediastrum duplex (Sphaeropleales, Chlorophyceae).

    PubMed

    McManus, Hilary A; Sanchez, Daniel J; Karol, Kenneth G

    2017-01-01

    Comparative studies of chloroplast genomes (plastomes) across the Chlorophyceae are revealing dynamic patterns of size variation, gene content, and genome rearrangements. Phylogenomic analyses are improving resolution of relationships, and uncovering novel lineages as new plastomes continue to be characterized. To gain further insight into the evolution of the chlorophyte plastome and increase the number of representative plastomes for the Sphaeropleales, this study presents two fully sequenced plastomes from the green algal family Hydrodictyaceae (Sphaeropleales, Chlorophyceae), one from Hydrodictyon reticulatum and the other from Pediastrum duplex. Genomic DNA from Hydrodictyon reticulatum and Pediastrum duplex was subjected to Illumina paired-end sequencing and the complete plastomes were assembled for each. Plastome size and gene content were characterized and compared with other plastomes from the Sphaeropleales. Homology searches using BLASTX were used to characterize introns and open reading frames (orfs) ≥ 300 bp. A phylogenetic analysis of gene order across the Sphaeropleales was performed. The plastome of Hydrodictyon reticulatum is 225,641 bp and Pediastrum duplex is 232,554 bp. The plastome structure and gene order of H. reticulatum and P. duplex are more similar to each other than to other members of the Sphaeropleales. Numerous unique open reading frames are found in both plastomes and the plastome of P. duplex contains putative viral protein genes, not found in other Sphaeropleales plastomes. Gene order analyses support the monophyly of the Hydrodictyaceae and their sister relationship to the Neochloridaceae. The complete plastomes of Hydrodictyon reticulatum and Pediastrum duplex, representing the largest of the Sphaeropleales sequenced thus far, once again highlight the variability in size, architecture, gene order and content across the Chlorophyceae. Novel intron insertion sites and unique orfs indicate recent, independent invasions into each

  18. Haematococcus as a promising cell factory to produce recombinant pharmaceutical proteins.

    PubMed

    Saei, Amir Ata; Ghanbari, Parisa; Barzegari, Abolfazl

    2012-11-01

    The need for recombinant pharmaceutical proteins has urged scientists all over the world to search for better protein expression systems which have higher capabilities and flexibilities. Although a number of protein expression systems are now available, no system is ideal and different systems lack specific properties. Here, microalga Haematococcus is discussed as a new protein expression system which merits cheap growth medium, fast growth rate, ease of manipulation and scale-up, ease of transformation, potential of exploiting in bioreactors and ability to exert post-translational modifications to the proteins. This green single-cell plant has favorable biological and biotechnological features for production of remarkable yields of recombinant proteins with high functionality. In this review article, we highlight the favorable biotechnological characteristics of Haematococcus for lowering costs and facilitating scale-up of recombinant protein production along with its superior biological features for genetic engineering.

  19. DEEP DIVISION IN THE CHLOROPHYCEAE (CHLOROPHYTA) REVEALED BY CHLOROPLAST PHYLOGENOMIC ANALYSES(1).

    PubMed

    Turmel, Monique; Brouard, Jean-Simon; Gagnon, Cédric; Otis, Christian; Lemieux, Claude

    2008-06-01

    The Chlorophyceae (sensu Mattox and Stewart) is a morphologically diverse class of the Chlorophyta displaying biflagellate and quadriflagellate motile cells with varying configurations of the flagellar apparatus. Phylogenetic analyses of 18S rDNA data and combined 18S and 26S rDNA data from a broad range of chlorophycean taxa uncovered five major monophyletic groups (Chlamydomonadales, Sphaeropleales, Oedogoniales, Chaetophorales, and Chaetopeltidales) but could not resolve their branching order. To gain insight into the interrelationships of these groups, we analyzed multiple genes encoded by the chloroplast genomes of Chlamydomonas reinhardtii P. A. Dang. and Chlamydomonas moewusii Gerloff (Chlamydomonadales), Scenedesmus obliquus (Turpin) Kütz. (Sphaeropleales), Oedogonium cardiacum Wittr. (Oedogoniales), Stigeoclonium helveticum Vischer (Chaetophorales), and Floydiella terrestris (Groover et Hofstetter) Friedl et O'Kelly (Chaetopeltidales). The C. moewusii, Oedogonium, and Floydiella chloroplast DNAs were partly sequenced using a random strategy. Trees were reconstructed from nucleotide and amino acid data sets derived from 44 protein-coding genes of 11 chlorophytes and nine streptophytes as well as from 57 protein-coding genes of the six chlorophycean taxa. All best trees identified two robustly supported major lineages within the Chlorophyceae: a clade uniting the Chlamydomonadales and Sphaeropleales, and a clade uniting the Oedogoniales, Chaetophorales, and Chaetopeltidales (OCC clade). This dichotomy is independently supported by molecular signatures in chloroplast genes, such as insertions/deletions and the distribution of trans-spliced group II introns. Within the OCC clade, the sister relationship observed for the Chaetophorales and Chaetopeltidales is also strengthened by independent data. Character state reconstruction of basal body orientation allowed us to refine hypotheses regarding the evolution of the flagellar apparatus.

  20. Ammonia and 1-octen-3-ol as attractants for Haematopota pluvialis, Hybomitra expollicata (Diptera: Tabanidae), and Morellia spp. (Diptera: Muscidae).

    PubMed

    Kristensen, P K; Sommer, C

    2000-11-01

    1-Octen-3-ol with and without ammonia were evaluated as attractants in canopy traps for Haematopota pluvialis L., Hybomitra expollicata Pand., and Morellia spp. Baited traps collected significantly more Tabanidae and female Morellia spp. than unbaited traps. 1-Octen-3-ol or 1-octen-3-ol with ammonia, increased catch by 4.2- and 4.3-fold for H. pluvialis, 5.9- and 8.6-fold for H. expollicata, and 1.2- and 1.6-fold for female Morellia spp., respectively.

  1. Enhancing Photon Utilization Efficiency for Astaxanthin Production from Haematococcus lacustris Using a Split-Column Photobioreactor.

    PubMed

    Kim, Z-Hun; Park, Hanwool; Lee, Ho-Sang; Lee, Choul-Gyun

    2016-07-28

    A split-column photobioreactor (SC-PBR), consisting of two bubble columns with different sizes, was developed to enhance the photon utilization efficiency in an astaxanthin production process from Haematococcus lacustris. Among the two columns, only the smaller column of SC-PBR was illuminated. Astaxanthin productivities and photon efficiencies of the SC-PBRs were compared with a standard bubble-column PBR (BC-PBR). Astaxanthin productivity of SC-PBR was improved by 28%, and the photon utilization efficiencies were 28-366% higher than the original BC-PBR. The results clearly show that the effective light regime of SC-PBR could enhance the production of astaxanthin.

  2. Phylogeny of Oedogoniales, Chaetophorales and Chaetopeltidales (Chlorophyceae): inferences from sequence-structure analysis of ITS2

    PubMed Central

    Buchheim, Mark A.; Sutherland, Danica M.; Schleicher, Tina; Förster, Frank; Wolf, Matthias

    2012-01-01

    Background and Aims The green algal class Chlorophyceae comprises five orders (Chlamydomonadales, Sphaeropleales, Chaetophorales, Chaetopeltidales and Oedogoniales). Attempts to resolve the relationships among these groups have met with limited success. Studies of single genes (18S rRNA, 26S rRNA, rbcL or atpB) have largely failed to unambiguously resolve the relative positions of Oedogoniales, Chaetophorales and Chaetopeltidales (the OCC taxa). In contrast, recent genomics analyses of plastid data from OCC exemplars provided a robust phylogenetic analysis that supports a monophyletic OCC alliance. Methods An ITS2 data set was assembled to independently test the OCC hypothesis and to evaluate the performance of these data in assessing green algal phylogeny at the ordinal or class level. Sequence-structure analysis designed for use with ITS2 data was employed for phylogenetic reconstruction. Key Results Results of this study yielded trees that were, in general, topologically congruent with the results from the genomic analyses, including support for the monophyly of the OCC alliance. Conclusions Not all nodes from the ITS2 analyses exhibited robust support, but our investigation demonstrates that sequence-structure analyses of ITS2 provide a taxon-rich means of testing phylogenetic hypotheses at high taxonomic levels. Thus, the ITS2 data, in the context of sequence-structure analysis, provide an economical supplement or alternative to the single-marker approaches used in green algal phylogeny. PMID:22028463

  3. Molecular systematics of Volvocales (Chlorophyceae, Chlorophyta) based on exhaustive 18S rRNA phylogenetic analyses.

    PubMed

    Nakada, Takashi; Misawa, Kazuharu; Nozaki, Hisayoshi

    2008-07-01

    The taxonomy of Volvocales (Chlorophyceae, Chlorophyta) was traditionally based solely on morphological characteristics. However, because recent molecular phylogeny largely contradicts the traditional subordinal and familial classifications, no classification system has yet been established that describes the subdivision of Volvocales in a manner consistent with the phylogenetic relationships. Towards development of a natural classification system at and above the generic level, identification and sorting of hundreds of sequences based on subjective phylogenetic definitions is a significant step. We constructed an 18S rRNA gene phylogeny based on 449 volvocalean sequences collected using exhaustive BLAST searches of the GenBank database. Many chimeric sequences, which can cause fallacious phylogenetic trees, were detected and excluded during data collection. The results revealed 21 strongly supported primary clades within phylogenetically redefined Volvocales. Phylogenetic classification following PhyloCode was proposed based on the presented 18S rRNA gene phylogeny along with the results of previous combined 18S and 26S rRNA and chloroplast multigene analyses.

  4. Morphological, molecular, and biochemical characterization of astaxanthin-producing green microalga Haematococcus sp. KORDI03 (Haematococcaceae, Chlorophyta) isolated from Korea.

    PubMed

    Kim, Ji Hyung; Affan, Abu; Jang, Jiyi; Kang, Mee-Hye; Ko, Ah-Ra; Jeon, Seon-Mi; Oh, Chulhong; Heo, Soo-Jin; Lee, Youn-Ho; Ju, Se-Jong; Kang, Do-Hyung

    2015-02-01

    A unicellular red microalga was isolated from environmental freshwater in Korea, and its morphological, molecular, and biochemical properties were characterized. Morphological analysis revealed that the isolate was a unicellular biflagellated green microalga that formed a non-motile, thick-walled palmelloid or red aplanospore. To determine the taxonomical position of the isolate, its 18S rRNA and rbcL genes were sequenced and phylogenetic analysis was performed. We found that the isolate was clustered together with other related Haematococcus strains showing differences in the rbcL gene. Therefore, the isolated microalga was classified into the genus Haematococcus, and finally designated Haematococcus sp. KORDI03. The microalga could be cultivated in various culture media under a broad range of pH and temperature conditions. Compositions of the microalgal cellular components were analyzed, and its protein, carbohydrate, and lipid compositions were estimated to be 21.1 ± 0.2%, 48.8 ± 1.8%, and 22.2 ± 0.9%, respectively. In addition, D-glucose and D-mannose were the dominant monosaccharides in the isolate, and its amino acids were composed mainly of aspartic acid, glutamic acid, alanine, and leucine. Moreover, several polyunsaturated fatty acids accounted for about 80% of the total fatty acids in Haematococcus sp. KORDI03, and the astaxanthin content in the red aplanospores was estimated to be 1.8% of the dry cell weight. To the best of our knowledge, this is the first report of an Haematococcus sp. isolated from Korea, which may be used for bioresource production in the microalgal industry.

  5. MITOCHONDRIAL DNA IN THE OOGAMOCHLAMYS CLADE (CHLOROPHYCEAE): HIGH GC CONTENT AND UNIQUE GENOME ARCHITECTURE FOR GREEN ALGAE(1).

    PubMed

    Borza, Tudor; Redmond, Erin K; Laflamme, Mark; Lee, Robert W

    2009-12-01

    Most mitochondrial genomes in the green algal phylum Chlorophyta are AT-rich, circular-mapping DNA molecules. However, mitochondrial genomes from the Reinhardtii clade of the Chlorophyceae lineage are linear and sometimes fragmented into subgenomic forms. Moreover, Polytomella capuana, from the Reinhardtii clade, has an elevated GC content (57.2%). In the present study, we examined mitochondrial genome conformation and GC bias in the Oogamochlamys clade of the Chlorophyceae, which phylogenetic data suggest is closely related to the Reinhardtii clade. Total DNA from selected Oogamochlamys taxa, including four Lobochlamys culleus (H. Ettl) Pröschold, B. Marin, U. G. Schlöss. et Melkonian strains, Lobochlamys segnis (H. Ettl) Pröschold, B. Marin, U. G. Schlöss. et Melkonian, and Oogamochlamys gigantea (O. Dill) Pröschold, B. Marin, U. G. Schlöss. et Melkonian, was subjected to Southern blot analyses with cob and cox1 probes, and the results suggest that the mitochondrial genome of these taxa is represented by multiple-sized linear DNA fragments with overlapping homologies. On the basis of these data, we propose that linear mitochondrial DNA with a propensity to become fragmented arose in an ancestor common to the Reinhardtii and Oogamochlamys clades or even earlier in the evolutionary history of the Chlorophyceae. Analyses of partial cob and cox1 sequences from these Oogamochlamys taxa revealed an unusually high GC content (49.9%-65.1%) and provided evidence for the accumulation of cob and cox1 pseudogenes and truncated sequences in the mitochondrial genome of all L. culleus strains examined.

  6. Proliferation of group II introns in the chloroplast genome of the green alga Oedocladium carolinianum (Chlorophyceae)

    PubMed Central

    Otis, Christian

    2016-01-01

    Background The chloroplast genome sustained extensive changes in architecture during the evolution of the Chlorophyceae, a morphologically and ecologically diverse class of green algae belonging to the Chlorophyta; however, the forces driving these changes are poorly understood. The five orders recognized in the Chlorophyceae form two major clades: the CS clade consisting of the Chlamydomonadales and Sphaeropleales, and the OCC clade consisting of the Oedogoniales, Chaetophorales, and Chaetopeltidales. In the OCC clade, considerable variations in chloroplast DNA (cpDNA) structure, size, gene order, and intron content have been observed. The large inverted repeat (IR), an ancestral feature characteristic of most green plants, is present in Oedogonium cardiacum (Oedogoniales) but is lacking in the examined members of the Chaetophorales and Chaetopeltidales. Remarkably, the Oedogonium 35.5-kb IR houses genes that were putatively acquired through horizontal DNA transfer. To better understand the dynamics of chloroplast genome evolution in the Oedogoniales, we analyzed the cpDNA of a second representative of this order, Oedocladium carolinianum. Methods The Oedocladium cpDNA was sequenced and annotated. The evolutionary distances separating Oedocladium and Oedogonium cpDNAs and two other pairs of chlorophycean cpDNAs were estimated using a 61-gene data set. Phylogenetic analysis of an alignment of group IIA introns from members of the OCC clade was performed. Secondary structures and insertion sites of oedogonialean group IIA introns were analyzed. Results The 204,438-bp Oedocladium genome is 7.9 kb larger than the Oedogonium genome, but its repertoire of conserved genes is remarkably similar and gene order differs by only one reversal. Although the 23.7-kb IR is missing the putative foreign genes found in Oedogonium, it contains sequences coding for a putative phage or bacterial DNA primase and a hypothetical protein. Intergenic sequences are 1.5-fold longer and

  7. Temperature responses of some North Atlantic Cladophora species (Chlorophyceae) in relation to their geographic distribution

    NASA Astrophysics Data System (ADS)

    Cambridge, M.; Breeman, A. M.; van Oosterwijk, R.; van den Hoek, C.

    1984-09-01

    The temperature responses for growth and survival have been experimentally tested for 6 species of the green algal genus Cladophora (Chlorophyceae; Cladophorales) (all isolated from Roscoff, Brittany, France, one also from Connecticut, USA), selected from 4 distribution groups, in order to determine which phase in the annual temperature regime might prevent the spread of a species beyond its present latitudinal range on the N. Atlantic coasts. For five species geographic limits could be specifically defined as due to a growth limit in the growing season or to a lethal limit in the adverse season. These species were: (1) C. coelothrix (Amphiatlantic tropical to warm temperate), with a northern boundary on the European coasts formed by a summer growth limit near the 12°C August isotherm. On the American coasts sea temperatures should allow its occurrence further north. (2) C. vagabunda (Amphiatlantic tropical to temperate), with a northern boundary formed by a summer growth limit near the 15°C August isotherm on both sides of the Atlantic. (3) C. dalmatica, as for C. vagabunda. (4) C. hutchinsiae (Mediterranean-Atlantic warm temperate), with a northern boundary formed by a summer growth limit near the 12°C August isotherm, and possibly also a winter lethal limit near the 6°C February isotherm; and a southern boundary formed by a southern lethal limit near the 26°C August isotherm. It is absent from the warm temperate American coast because its lethal limits, 5° and 30°C, are regularly reached there. (5) Preliminary data for C. rupestris (Amphiatlantic temperate), suggest the southeastern boundary on the African coast to be a summer lethal limit near the 26°C August isotherm; the southwestern boundary on the American coast lies on the 20°C August isotherm. For one species, C. albida, the experimental growth and survival range was wider than expected from its geographic distribution, and reasons to account for this are suggested.

  8. Probing the Monophyly of the Sphaeropleales (Chlorophyceae) Using Data From Five Genes.

    PubMed

    Tippery, Nicholas P; Fučíková, Karolina; Lewis, Paul O; Lewis, Louise A

    2012-12-01

    Molecular phylogenetic analyses have had a major impact on the classification of the green algal class Chlorophyceae, corroborating some previous evolutionary hypotheses, but primarily promoting new interpretations of morphological evolution. One set of morphological traits that feature prominently in green algal systematics is the absolute orientation of the flagellar apparatus in motile cells, which correlates strongly with taxonomic classes and orders. The order Sphaeropleales includes diverse green algae sharing the directly opposite (DO) flagellar apparatus orientation of their biflagellate motile cells. However, algae across sphaeroplealean families differ in specific components of the DO flagellar apparatus, and molecular phylogenetic studies often have failed to provide strong support for the monophyly of the order. To test the monophyly of Sphaeropleales and of taxa with the DO flagellar apparatus, we conducted a molecular phylogenetic study of 16 accessions representing all known families and diverse affiliated lineages within the order, with data from four plastid genes (psaA, psaB, psbC, rbcL) and one nuclear ribosomal gene (18S). Although single-gene analyses varied in topology and support values, analysis of combined data strongly supported a monophyletic Sphaeropleales. Our results also corroborated previous phylogenetic hypotheses that were based on chloroplast genome data from relatively few taxa. Specifically, our data resolved Volvocales, algae possessing predominantly biflagellate motile cells with clockwise (CW) flagellar orientation, as the monophyletic sister lineage to Sphaeropleales, and an alliance of Chaetopeltidales, Chaetophorales, and Oedogoniales, orders having multiflagellate motile cells with distinct flagellar orientations involving the DO and CW forms. © 2012 Phycological Society of America.

  9. Phytohormones as regulators of heavy metal biosorption and toxicity in green alga Chlorella vulgaris (Chlorophyceae).

    PubMed

    Piotrowska-Niczyporuk, Alicja; Bajguz, Andrzej; Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata

    2012-03-01

    The present study was undertaken to test the influence of exogenously applied phytohormones: auxins (IAA, IBA, NAA, PAA), cytokinins (BA, CPPU, DPU, 2iP, Kin, TDZ, Z), gibberellin (GA(3)), jasmonic acid (JA) as well as polyamine - spermidine (Spd) upon the growth and metabolism of green microalga Chlorella vulgaris (Chlorophyceae) exposed to heavy metal (Cd, Cu, Pb) stress. The inhibitory effect of heavy metals on algal growth, metabolite accumulation and enzymatic as well as non-enzymatic antioxidant system was arranged in the following order: Cd > Pb > Cu. Exogenously applied phytohormones modify the phytotoxicity of heavy metals. Auxins, cytokinins, gibberellin and spermidine (Spd) can alleviate stress symptoms by inhibiting heavy metal biosorption, restoring algal growth and primary metabolite level. Moreover, these phytohormones and polyamine stimulate antioxidant enzymes' (superoxide dismutase, ascorbate peroxidase, catalase) activities and ascorbate as well as glutathione accumulation by producing increased antioxidant capacity in cells growing under abiotic stress. Increased activity of antioxidant enzymes reduced oxidative stress expressed by lipid peroxidation and hydrogen peroxide level. In contrast JA enhanced heavy metal toxicity leading to increase in metal biosorption and ROS generation. The decrease in cell number, chlorophylls, carotenoids, monosaccharides, soluble proteins, ascorbate and glutathione content as well as antioxidant enzyme activity was also obtained in response to JA and heavy metals. Determining the stress markers (lipid peroxidation, hydrogen peroxide) and antioxidants' level as well as antioxidant enzyme activity in cells is important for understanding the metal-specific mechanisms of toxicity and that these associated novel endpoints may be useful metrics for accurately predicting toxicity. The data suggest that phytohormones and polyamine play an important role in the C. vulgaris responding to abiotic stressor and algal

  10. The Exceptionally Large Chloroplast Genome of the Green Alga Floydiella terrestris Illuminates the Evolutionary History of the Chlorophyceae

    PubMed Central

    Brouard, Jean-Simon; Otis, Christian; Lemieux, Claude; Turmel, Monique

    2010-01-01

    The Chlorophyceae, an advanced class of chlorophyte green algae, comprises five lineages that form two major clades (Chlamydomonadales + Sphaeropleales and Oedogoniales + Chaetopeltidales + Chaetophorales). The four complete chloroplast DNA (cpDNA) sequences currently available for chlorophyceans uncovered an extraordinarily fluid genome architecture as well as many structural features distinguishing this group from other green algae. We report here the 521,168-bp cpDNA sequence from a member of the Chaetopeltidales (Floydiella terrestris), the sole chlorophycean lineage not previously sampled for chloroplast genome analysis. This genome, which contains 97 conserved genes and 26 introns (19 group I and 7 group II introns), is the largest chloroplast genome ever sequenced. Intergenic regions account for 77.8% of the genome size and are populated by short repeats. Numerous genomic features are shared with the cpDNA of the chaetophoralean Stigeoclonium helveticum, notably the absence of a large inverted repeat and the presence of unique gene clusters and trans-spliced group II introns. Although only one of the Floydiella group I introns encodes a homing endonuclease gene, our finding of five free-standing reading frames having similarity with such genes suggests that chloroplast group I introns endowed with mobility were once more abundant in the Floydiella lineage. Parsimony analysis of structural genomic features and phylogenetic analysis of chloroplast sequence data unambiguously resolved the Oedogoniales as sister to the Chaetopeltidales and Chaetophorales. An evolutionary scenario of the molecular events that shaped the chloroplast genome in the Chlorophyceae is presented. PMID:20624729

  11. Specific light uptake rates can enhance astaxanthin productivity in Haematococcus lacustris.

    PubMed

    Lee, Ho-Sang; Kim, Z-Hun; Park, Hanwool; Lee, Choul-Gyun

    2016-05-01

    Lumostatic operation was applied for efficient astaxanthin production in autotrophic Haematococcus lacustris cultures using 0.4-L bubble column photobioreactors. The lumostatic operation in this study was performed with three different specific light uptake rates (q(e)) based on cell concentration, cell projection area, and fresh weight as one-, two- and three-dimensional characteristics values, respectively. The q(e) value from the cell concentration (q(e1D)) obtained was 13.5 × 10⁻⁸ μE cell⁻¹ s⁻¹, and the maximum astaxanthin concentration was increased to 150 % compared to that of a control with constant light intensity. The other optimum q e values by cell projection area (q(e2D)) and fresh weight (q( e3D)) were determined to be 195 μE m⁻² s⁻¹ and 10.5 μE g⁻¹ s⁻¹ for astaxanthin production, respectively. The maximum astaxanthin production from the lumostatic cultures using the parameters controlled by cell projection area (2D) and fresh weight (3D) also increased by 36 and 22% over that of the controls, respectively. When comparing the optimal q e values among the three different types, the lumostatic cultures using q(e) based on fresh weight showed the highest astaxanthin productivity (22.8 mg L⁻¹ day⁻¹), which was a higher level than previously reported. The lumostatic operations reported here demonstrated that more efficient and effective astaxanthin production was obtained by H. lacustris than providing a constant light intensity, regardless of which parameter is used to calculate the specific light uptake rate.

  12. Tetraflagellochloris mauritanica gen. et sp. nov. (Chlorophyceae), a New Flagellated Alga from the Mauritanian Desert: Morphology, Ultrastructure, and Phylogenetic Framing.

    PubMed

    Barsanti, Laura; Frassanito, Anna Maria; Passarelli, Vincenzo; Evangelista, Valtere; Etebari, Maryam; Paccagnini, Eugenio; Lupetti, Pietro; Lenzi, Paola; Verni, Franco; Gualtieri, Paolo

    2013-02-01

    Morphological, ultrastructural, and molecular-sequence data were used to assess the phylogenetic position of a tetraflagellate green alga isolated from soil samples of a saline dry basin near F'derick, Mauritania. This alga can grow as individual cells or form non-coenobial colonies of up to 12 individuals. It has a parietal chloroplast with an embedded pyrenoid covered by a starch sheath and traversed by single parallel thylakoids, and an eyespot located in a parietal position opposite to the flagellar insertion. Lipid vacuoles are present in the cytoplasm. Microspectroscopy indicated the presence of chlorophylls a and b, with lutein as the major carotenoid in the chloroplast, while the eyespot spectrum has a shape typical of green-algal eyespots. The cell has four flagella, two of them long and two considerably shorter. Sequence data from the 18S rRNA gene and ITS2 were obtained and compared with published sequences for green algae. Results from morphological and ultrastructural examinations and sequence analysis support the placement of this alga in the Chlorophyceae, as Tetraflagellochloris mauritanica L. Barsanti et A. Barsanti, gen. et sp. nov. © 2012 Phycological Society of America.

  13. New Design Strategy for Development of Specific Primer Sets for PCR-Based Detection of Chlorophyceae and Bacillariophyceae in Environmental Samples▿ †

    PubMed Central

    Valiente Moro, Claire; Crouzet, Olivier; Rasconi, Séréna; Thouvenot, Antoine; Coffe, Gérard; Batisson, Isabelle; Bohatier, Jacques

    2009-01-01

    Studying aquatic microalgae is essential for monitoring biodiversity and water quality. We designed new sets of 18S rRNA PCR primers for Chlorophyceae and Bacillariophyceae by using the ARB software and implementing a virtual PCR program. The results of specificity analysis showed that most of the targeted algal families were identified and nontargeted organisms, such as fungi or ciliates, were excluded. These newly developed PCR primer sets were also able to amplify microalgal rRNA genes from environmental samples with accurate specificity. These tools could be of great interest for studying freshwater microalgal ecology and for developing bioindicators of the health status of aquatic environments. PMID:19592531

  14. New design strategy for development of specific primer sets for PCR-based detection of Chlorophyceae and Bacillariophyceae in environmental samples.

    PubMed

    Moro, Claire Valiente; Crouzet, Olivier; Rasconi, Séréna; Thouvenot, Antoine; Coffe, Gérard; Batisson, Isabelle; Bohatier, Jacques

    2009-09-01

    Studying aquatic microalgae is essential for monitoring biodiversity and water quality. We designed new sets of 18S rRNA PCR primers for Chlorophyceae and Bacillariophyceae by using the ARB software and implementing a virtual PCR program. The results of specificity analysis showed that most of the targeted algal families were identified and nontargeted organisms, such as fungi or ciliates, were excluded. These newly developed PCR primer sets were also able to amplify microalgal rRNA genes from environmental samples with accurate specificity. These tools could be of great interest for studying freshwater microalgal ecology and for developing bioindicators of the health status of aquatic environments.

  15. Hiding in plain sight: Koshicola spirodelophila gen. et sp. nov. (Chaetopeltidales, Chlorophyceae), a novel green alga associated with the aquatic angiosperm Spirodela polyrhiza.

    PubMed

    Watanabe, Shin; Fučíková, Karolina; Lewis, Louise A; Lewis, Paul O

    2016-05-01

    Discovery and morphological characterization of a novel epiphytic aquatic green alga increases our understanding of Chaetopeltidales, a poorly known order in Chlorophyceae. Chloroplast genomic data from this taxon reveals an unusual architecture previously unknown in green algae. Using light and electron microscopy, we characterized the morphology and ultrastructure of a novel taxon of green algae. Bayesian phylogenetic analyses of nuclear and plastid genes were used to test the hypothesized membership of this taxon in order Chaetopeltidales. With next-generation sequence data, we assembled the plastid genome of this novel taxon and compared its gene content and architecture to that of related species to further investigate plastid genome traits. The morphology and ultrastructure of this alga are consistent with placement in Chaetopeltidales (Chlorophyceae), but a distinct trait combination supports recognition of this alga as a new genus and species-Koshicola spirodelophila gen. et sp. nov. Its placement in the phylogeny as a descendant of a deep division in the Chaetopeltidales is supported by analysis of molecular data sets. The chloroplast genome is among the largest reported in green algae and the genes are distributed on three large (rather than a single) chromosome, in contrast to other studied green algae. The discovery of Koshicola spirodelophila gen. et sp. nov. highlights the importance of investigating even commonplace habitats to explore new microalgal diversity. This work expands our understanding of the morphological and chloroplast genomic features of green algae, and in particular those of the poorly studied Chaetopeltidales. © 2016 Botanical Society of America.

  16. Evolution of rbcL group IA introns and intron open reading frames within the colonial Volvocales (Chlorophyceae).

    PubMed

    Nozaki, Hisayoshi; Takahara, Manabu; Nakazawa, Atsushi; Kita, Yoko; Yamada, Takashi; Takano, Hiroyoshi; Kawano, Shigeyuki; Kato, Masahiro

    2002-06-01

    Mobile group I introns sometimes contain an open reading frame (ORF) possibly encoding a site-specific DNA endonuclease. However, previous phylogenetic studies have not clearly deduced the evolutionary roles of the group I intron ORFs. In this paper, we examined the phylogeny of group IA2 introns inserted in the position identical to that of the chloroplast-encoded rbcL coding region (rbcL-462 introns) and their ORFs from 13 strains of five genera (Volvox, Pleodorina, Volvulina, Astrephomene, and Gonium) of the colonial Volvocales (Chlorophyceae) and a related unicellular green alga, Vitreochlamys. The rbcL-462 introns contained an intact or degenerate ORF of various sizes except for the Gonium multicoccum rbcL-462 intron. Partial amino acid sequences of some rbcL-462 intron ORFs exhibited possible homology to the endo/excinuclease amino acid terminal domain. The distribution of the rbcL-462 introns is sporadic in the phylogenetic trees of the colonial Volvocales based on the five chloroplast exon sequences (6021 bp). Phylogenetic analyses of the conserved intron sequences resolved that the G. multicoccum rbcL-462 intron had a phylogenetic position separate from those of other colonial volvocalean rbcL-462 introns, indicating the recent horizontal transmission of the intron in the G. multicoccum lineage. However, the combined data set from conserved intron sequences and ORFs from most of the rbcL-462 introns resolved robust phylogenetic relationships of the introns that were consistent with those of the host organisms. Therefore, most of the extant rbcL-462 introns may have been vertically inherited from the common ancestor of their host organisms, whereas such introns may have been lost in other lineages during evolution of the colonial Volvocales. In addition, apparently higher synonymous substitutions than nonsynonymous substitutions in the rbcL-462 intron ORFs indicated that the ORFs might evolve under functional constraint, which could result in homing of the

  17. Resolving the phylogenetic relationship between Chlamydomonas sp. UWO 241 and Chlamydomonas raudensis sag 49.72 (Chlorophyceae) with nuclear and plastid DNA sequences.

    PubMed

    Possmayer, Marc; Gupta, Rajesh K; Szyszka-Mroz, Beth; Maxwell, Denis P; Lachance, Marc-André; Hüner, Norman P A; Smith, David Roy

    2016-04-01

    The Antarctic psychrophilic green alga Chlamy-domonas sp. UWO 241 is an emerging model for studying microbial adaptation to polar environments. However, little is known about its evolutionary history and its phylogenetic relationship with other chlamydomonadalean algae is equivocal. Here, we attempt to clarify the phylogenetic position of UWO 241, specifically with respect to Chlamydomonas rau-densis SAG 49.72. Contrary to a previous report, we show that UWO 241 is a distinct species from SAG 49.72. Our phylogenetic analyses of nuclear and plastid DNA sequences reveal that UWO 241 represents a unique lineage within the Moewusinia clade (sensu Nakada) of the Chlamydomonadales (Chlorophyceae, Chlorophyta), closely affiliated to the marine species Chlamydomonas parkeae SAG 24.89. © 2016 The Authors. Journal of Phycology published by Wiley Periodicals, Inc. on behalf of Phycological Society of America.

  18. The Chloroplast Genome of the Green Alga Schizomeris leibleinii (Chlorophyceae) Provides Evidence for Bidirectional DNA Replication from a Single Origin in the Chaetophorales

    PubMed Central

    Brouard, Jean-Simon; Otis, Christian; Lemieux, Claude; Turmel, Monique

    2011-01-01

    In the Chlorophyceae, the chloroplast genome is extraordinarily fluid in architecture and displays unique features relative to other groups of green algae. For the Chaetophorales, 1 of the 5 major lineages of the Chlorophyceae, it has been shown that the distinctive architecture of the 223,902-bp genome of Stigeoclonium helveticum is consistent with bidirectional DNA replication from a single origin. Here, we report the 182,759-bp chloroplast genome sequence of Schizomeris leibleinii, a member of the earliest diverging lineage of the Chaetophorales. Like its Stigeoclonium homolog, the Schizomeris genome lacks a large inverted repeat encoding the rRNA operon and displays a striking bias in coding regions that is associated with a bias in base composition along each strand. Our results support the notion that these two chaetophoralean genomes replicate bidirectionally from a putative origin located in the vicinity of the small subunit ribosomal RNA gene. Their shared structural characteristics were most probably inherited from the common ancestor of all chaetophoralean algae. Short dispersed repeats account for most of the 41-kb size variation between the Schizomeris and Stigeoclonium genomes, and there is no indication that homologous recombination between these repeated elements led to the observed gene rearrangements. A comparison of the extent of variation sustained by the Stigeoclonium and Schizomeris chloroplast DNAs (cpDNAs) with that observed for the cpDNAs of the chlamydomonadalean Chlamydomonas and Volvox suggests that gene rearrangements as well as changes in the abundance of intergenic and intron sequences occurred at a slower pace in the Chaetophorales than in the Chlamydomonadales. PMID:21546564

  19. DESCRIPTION OF TWO NEW MONOECIOUS SPECIES OF VOLVOX SECT. VOLVOX (VOLVOCACEAE, CHLOROPHYCEAE), BASED ON COMPARATIVE MORPHOLOGY AND MOLECULAR PHYLOGENY OF CULTURED MATERIAL(1).

    PubMed

    Isaka, Nanako; Kawai-Toyooka, Hiroko; Matsuzaki, Ryo; Nakada, Takashi; Nozaki, Hisayoshi

    2012-06-01

    Species of Volvox sect. Volvox (Volvocaceae, Chlorophyceae) are unique because they have thick cytoplasmic bridges between somatic cells and spiny-walled zygotes. This section is taxonomically important because the genus Volvox is polyphyletic. However, taxonomic studies of species in Volvox sect. Volvox have not been carried out on cultured material. Here, we performed a taxonomic study of monoecious species of Volvox sect. Volvox based on the comparative morphology and molecular phylogeny of chloroplast genes and the internal transcribed spacer (ITS) regions of nuclear rDNA using various strains originating from Japan and two preserved strains from the USA. The strains were clearly divided into four species, V. globator L., V. barberi W. Shaw, V. kirkiorum sp. nov., and V. ferrisii sp. nov., on the basis of differences in numbers of zygotes (eggs) in the sexual spheroids, form of zygote wall, and somatic cell shape. Sequences for ITS of nuclear rDNA resolved that the two new species have phylogenetic positions separated from V. globator, V. barberi, V. capensis F. Rich et Pocock, and V. rousseletii G. S. West UTEX 1862 within Volvox sect. Volvox.

  20. Chloroplast DNA sequence of the green alga Oedogonium cardiacum (Chlorophyceae): Unique genome architecture, derived characters shared with the Chaetophorales and novel genes acquired through horizontal transfer

    PubMed Central

    Brouard, Jean-Simon; Otis, Christian; Lemieux, Claude; Turmel, Monique

    2008-01-01

    Background To gain insight into the branching order of the five main lineages currently recognized in the green algal class Chlorophyceae and to expand our understanding of chloroplast genome evolution, we have undertaken the sequencing of chloroplast DNA (cpDNA) from representative taxa. The complete cpDNA sequences previously reported for Chlamydomonas (Chlamydomonadales), Scenedesmus (Sphaeropleales), and Stigeoclonium (Chaetophorales) revealed tremendous variability in their architecture, the retention of only few ancestral gene clusters, and derived clusters shared by Chlamydomonas and Scenedesmus. Unexpectedly, our recent phylogenies inferred from these cpDNAs and the partial sequences of three other chlorophycean cpDNAs disclosed two major clades, one uniting the Chlamydomonadales and Sphaeropleales (CS clade) and the other uniting the Oedogoniales, Chaetophorales and Chaetopeltidales (OCC clade). Although molecular signatures provided strong support for this dichotomy and for the branching of the Oedogoniales as the earliest-diverging lineage of the OCC clade, more data are required to validate these phylogenies. We describe here the complete cpDNA sequence of Oedogonium cardiacum (Oedogoniales). Results Like its three chlorophycean homologues, the 196,547-bp Oedogonium chloroplast genome displays a distinctive architecture. This genome is one of the most compact among photosynthetic chlorophytes. It has an atypical quadripartite structure, is intron-rich (17 group I and 4 group II introns), and displays 99 different conserved genes and four long open reading frames (ORFs), three of which are clustered in the spacious inverted repeat of 35,493 bp. Intriguingly, two of these ORFs (int and dpoB) revealed high similarities to genes not usually found in cpDNA. At the gene content and gene order levels, the Oedogonium genome most closely resembles its Stigeoclonium counterpart. Characters shared by these chlorophyceans but missing in members of the CS clade

  1. The complete mitochondrial DNA sequence of the green alga Pseudendoclonium akinetum (Ulvophyceae) highlights distinctive evolutionary trends in the chlorophyta and suggests a sister-group relationship between the Ulvophyceae and Chlorophyceae.

    PubMed

    Pombert, Jean-François; Otis, Christian; Lemieux, Claude; Turmel, Monique

    2004-05-01

    The mitochondrial genome has undergone radical changes in both the Chlorophyta and Streptophyta, yet little is known about the dynamics of mtDNA evolution in either of these lineages. In the Chlorophyta, which comprises four of the five recognized classes of green algae (Prasinophyceae, Trebouxiophyceae, Ulvophyceae, and Chlorophyceae), the mitochondrial genome varies from 16 to 55 kb. This genome has retained a compact gene organization and a relatively complex gene repertoire ("ancestral" pattern) in the basal lineages represented by the Trebouxiophyceae and Prasinophyceae, whereas it has been reduced in size and gene complement and tends to evolve much more rapidly at the sequence level ("reduced-derived" pattern of evolution) in the Chlorophyceae and the lineage leading to the enigmatic chlorophyte Pedinomonas. To gain information about the evolutionary trends of mtDNA in the Ulvophyceae and also to gain insights into the phylogenetic relationships between ulvophytes and other chlorophytes, we have determined the mtDNA sequence of Pseudendoclonium akinetum. At 95,880 bp, Pseudendoclonium mtDNA is the largest green-algal mitochondrial genome sequenced to date and has the lowest gene density. These derived features are reminiscent of the "expanded" pattern exhibited by embryophyte mtDNAs, indicating that convergent evolution towards genome expansion has occurred independently in the Chlorophyta and Streptophyta. With 57 conserved genes, the gene repertoire of Pseudendoclonium mtDNA is slightly smaller than those of the prasinophyte Nephroselmis olivacea and the trebouxiophyte Prototheca wickerhamii. This ulvophyte mtDNA contains seven group I introns, four of which have homologs in green-algal mtDNAs displaying an "ancestral" or a "reduced-derived" pattern of evolution. Like its counterpart in the chlorophycean green alga Scenedesmus obliquus, it features numerous small, dispersed repeats in intergenic regions and introns. Its overall rate of sequence evolution

  2. Adaptation of Selenastrum capricornutum (Chlorophyceae) to copper

    USGS Publications Warehouse

    Kuwabara, J.S.; Leland, H.V.

    1986-01-01

    Selenastrum capricornutum Printz, growing in a chemically defined medium, was used as a model for studying adaptation of algae to a toxic metal (copper) ion. Cells exhibited lag-phase adaptation to 0.8 ??M total Cu (10-12 M free ion concentration) after 20 generations of Cu exposure. Selenastrum adapted to the same concentration when Cu was gradually introduced over an 8-h period using a specially designed apparatus that provided a transient increase in exposure concentration. Cu adaptation was not attributable to media conditioning by algal exudates. Duration of lag phase was a more sensitive index of copper toxicity to Selenastrum that was growth rate or stationary-phase cell density under the experimental conditions used. Chemical speciation of the Cu dosing solution influenced the duration of lag phase even when media formulations were identical after dosing. Selenastrum initially exposed to Cu in a CuCl2 injection solution exhibited a lag phase of 3.9 d, but this was reduced to 1.5 d when a CuEDTA solution was used to achieve the same total Cu and EDTA concentrations. Physical and chemical processes that accelerated the rate of increase in cupric ion concentration generally increased the duration of lag phase. ?? 1986.

  3. Influence of TiO2 Nanoparticles on Growth and Phenolic Compounds Production in Photosynthetic Microorganisms

    PubMed Central

    Comotto, Mattia; Casazza, Alessandro Alberto; Aliakbarian, Bahar; Caratto, Valentina; Ferretti, Maurizio; Perego, Patrizia

    2014-01-01

    The influence of titanium dioxide nanoparticles (pure anatase and 15% N doped anatase) on the growth of Chlorella vulgaris, Haematococcus pluvialis, and Arthrospira platensis was investigated. Results showed that pure anatase can lead to a significant growth inhibition of C. vulgaris and A. platensis (17.0 and 74.1%, resp.), while for H. pluvialis the nanoparticles do not cause a significant inhibition. Since in these stress conditions photosynthetic microorganisms can produce antioxidant compounds in order to prevent cell damages, we evaluated the polyphenols content either inside the cells or released in the medium. Although results did not show a significant difference in C. vulgaris, the phenolic concentrations of two other microorganisms were statistically affected by the presence of titanium dioxide. In particular, 15% N doped anatase resulted in a higher production of extracellular antioxidant compounds, reaching the concentration of 65.2 and 68.0 mg gDB−1 for H. pluvialis and A. platensis, respectively. PMID:25610914

  4. THE FLAGELLAR PHOTORESPONSE IN VOLVOX SPECIES (VOLVOCACEAE, CHLOROPHYCEAE)(1).

    PubMed

    Solari, Cristian A; Drescher, Knut; Goldstein, Raymond E

    2011-06-01

    Steering their swimming direction toward the light is crucial for the viability of Volvox colonies, the larger members of the volvocine algae. While it is known that this phototactic steering is achieved by a difference in behavior of the flagella on the illuminated and shaded sides, conflicting reports suggest that this asymmetry arises either from a change in beating direction or a change in beating frequency. Here, we report direct observations of the flagellar behavior of various Volvox species with different phyletic origin in response to light intensity changes and thereby resolve this controversy: Volvox barberi W. Shaw from the section Volvox sensu Nozaki (2003) changes the direction of the flagellar beating plane, while species encompassed in the group Eudorina (Volvox carteri F. Stein, Volvox aureus Ehrenb., and Volvox tertius Art. Mey.) decrease the flagellar beating frequency, sometimes down to flagellar arrest. © 2011 Phycological Society of America.

  5. VOLVOX BARBERI, THE FASTEST SWIMMER OF THE VOLVOCALES (CHLOROPHYCEAE)(1).

    PubMed

    Solari, Cristian A; Michod, Richard E; Goldstein, Raymond E

    2008-12-01

    Volvox barberi W. Shaw is a volvocalean green alga composed of biflagellated cells. Vovocales with 16 cells or more form spherical colonies, and their largest members have germ-soma separation (all species in the genus Volvox). V. barberi is the largest Volvox species recorded in terms of cell number (10,000-50,000 cells) and has the highest somatic to reproductive cell ratio (S/R). Since they are negatively buoyant, Volvocales need flagellar beating to avoid sinking and to reach light and nutrients. We measured V. barberi swimming speed and total swimming force. V. barberi swimming speeds are the highest recorded so far for volvocine algae (∼600 μm · s(-1) ). With this speed, V. barberi colonies have the potential to perform daily vertical migrations in the water column at speeds of 2-3 m · h(-1) , consistent with what has been reported about Volvox populations in the wild. Moreover, V. barberi data fit well in the scaling relationships derived with the other smaller Volvox species, namely, that the upward swimming speed Vup ∝N(0.28) and the total swimming force FS ∝N(0.77) (N = colony cell number). These allometric relationships have been important supporting evidence for reaching the conclusion that as size increases, colonies have to invest in cell specialization and increase their S/R to increase their motility capabilities to stay afloat and motile. © 2008 Phycological Society of America.

  6. Swimming patterns of the quadriflagellate Tetraflagellochloris mauritanica (Chlamydomonadales, Chlorophyceae).

    PubMed

    Barsanti, Laura; Coltelli, Primo; Evangelista, Valtere; Frassanito, Anna Maria; Gualtieri, Paolo

    2016-04-01

    Chlamydomonadales are elective subjects for the investigation of the problems related to locomotion and transport in biological fluid dynamics, whose resolution could enhance searching efficiency and assist in the avoidance of dangerous environments. In this paper, we elucidate the swimming behavior of Tetraflagellochloris mauritanica, a unicellular-multicellular alga belonging to the order Chlamydomonadales. This quadriflagellate alga has a complex swimming motion consisting of alternating swimming phases connected by in-place random reorientations and resting phases. It is capable of both forward and backward swimming, both being normal modes of swimming. The complex swimming behavior resembles the run-and-tumble motion of peritrichous bacteria, with in-place reorientation taking the place of tumbles. In the forward swimming, T. mauritanica shows a very efficient flagellar beat, with undulatory retrograde waves that run along the flagella to their tip. In the backward swimming, the flagella show a nonstereotypical synchronization mode, with a pattern that does not fit any of the modes present in the other Chlamydomonadales so far investigated.

  7. Astaxanthin: Sources, Extraction, Stability, Biological Activities and Its Commercial Applications—A Review

    PubMed Central

    Ambati, Ranga Rao; Siew Moi, Phang; Ravi, Sarada; Aswathanarayana, Ravishankar Gokare

    2014-01-01

    There is currently much interest in biological active compounds derived from natural resources, especially compounds that can efficiently act on molecular targets, which are involved in various diseases. Astaxanthin (3,3′-dihydroxy-β, β′-carotene-4,4′-dione) is a xanthophyll carotenoid, contained in Haematococcus pluvialis, Chlorella zofingiensis, Chlorococcum, and Phaffia rhodozyma. It accumulates up to 3.8% on the dry weight basis in H. pluvialis. Our recent published data on astaxanthin extraction, analysis, stability studies, and its biological activities results were added to this review paper. Based on our results and current literature, astaxanthin showed potential biological activity in in vitro and in vivo models. These studies emphasize the influence of astaxanthin and its beneficial effects on the metabolism in animals and humans. Bioavailability of astaxanthin in animals was enhanced after feeding Haematococcus biomass as a source of astaxanthin. Astaxanthin, used as a nutritional supplement, antioxidant and anticancer agent, prevents diabetes, cardiovascular diseases, and neurodegenerative disorders, and also stimulates immunization. Astaxanthin products are used for commercial applications in the dosage forms as tablets, capsules, syrups, oils, soft gels, creams, biomass and granulated powders. Astaxanthin patent applications are available in food, feed and nutraceutical applications. The current review provides up-to-date information on astaxanthin sources, extraction, analysis, stability, biological activities, health benefits and special attention paid to its commercial applications. PMID:24402174

  8. Astaxanthin: sources, extraction, stability, biological activities and its commercial applications--a review.

    PubMed

    Ambati, Ranga Rao; Phang, Siew Moi; Ravi, Sarada; Aswathanarayana, Ravishankar Gokare

    2014-01-07

    There is currently much interest in biological active compounds derived from natural resources, especially compounds that can efficiently act on molecular targets, which are involved in various diseases. Astaxanthin (3,3'-dihydroxy-β, β'-carotene-4,4'-dione) is a xanthophyll carotenoid, contained in Haematococcus pluvialis, Chlorella zofingiensis, Chlorococcum, and Phaffia rhodozyma. It accumulates up to 3.8% on the dry weight basis in H. pluvialis. Our recent published data on astaxanthin extraction, analysis, stability studies, and its biological activities results were added to this review paper. Based on our results and current literature, astaxanthin showed potential biological activity in in vitro and in vivo models. These studies emphasize the influence of astaxanthin and its beneficial effects on the metabolism in animals and humans. Bioavailability of astaxanthin in animals was enhanced after feeding Haematococcus biomass as a source of astaxanthin. Astaxanthin, used as a nutritional supplement, antioxidant and anticancer agent, prevents diabetes, cardiovascular diseases, and neurodegenerative disorders, and also stimulates immunization. Astaxanthin products are used for commercial applications in the dosage forms as tablets, capsules, syrups, oils, soft gels, creams, biomass and granulated powders. Astaxanthin patent applications are available in food, feed and nutraceutical applications. The current review provides up-to-date information on astaxanthin sources, extraction, analysis, stability, biological activities, health benefits and special attention paid to its commercial applications.

  9. Erratum: Water Science and Technology 72 (7): Development of a new wastewater treatment process for resource recovery of carotenoids, H. Sato, H. Nagare, T. N. C. Huynh and H. Komatsu, doi: 10.2166/wst.2015.330.

    PubMed

    2016-01-01

    A new wastewater treatment process that involves coagulation, ozonation, and microalgae cultivation has been developed. Here, two challenges are discussed. The first was minimizing phosphorus removal during coagulation in order to maximize algal production. The second was to optimize microalgae cultivation; algal species that grow rapidly and produce valuable products are ideal for selection. Haematococcus pluvialis, which produces the carotenoid astaxanthin, was used. Growth rate, nutrient removal ability, and astaxanthin production of H. pluvialis in coagulated wastewater were investigated. After coagulation with chitosan, the turbidity and suspended solids decreased by 89% ± 8% and 73% ± 16%, respectively. The nitrogen and phosphorus contents of the supernatant remained at 86% ± 6% and 67% ± 24%, respectively. These results indicate that coagulation with chitosan can remove turbidity and SS while preserving nutrients. H. pluvialis grew well in the supernatant of coagulated wastewater. The astaxanthin yield from coagulated wastewater in which microalgae were cultured was 3.26 mg/L, and total phosphorus and nitrogen contents decreased 99% ± 1% and 90% ± 8% (Days 31-35), respectively.

  10. Development of a new wastewater treatment process for resource recovery of carotenoids.

    PubMed

    Sato, H; Nagare, H; Huynh, T N C; Komatsu, H

    2015-01-01

    A new wastewater treatment process that involves coagulation, ozonation, and microalgae cultivation has been developed. Here, two challenges are discussed. The first was minimizing phosphorus removal during coagulation in order to maximize algal production. The second was to optimize microalgae cultivation; algal species that grow rapidly and produce valuable products are ideal for selection. Haematococcus pluvialis, which produces the carotenoid astaxanthin, was used. Growth rate, nutrient removal ability, and astaxanthin production of H. pluvialis in coagulated wastewater were investigated. After coagulation with chitosan, the turbidity and suspended solids decreased by 89% ± 8% and 73% ± 16%, respectively. The nitrogen and phosphorus contents of the supernatant remained at 86% ± 6% and 67% ± 24%, respectively. These results indicate that coagulation with chitosan can remove turbidity and SS while preserving nutrients. H. pluvialis grew well in the supernatant of coagulated wastewater. The astaxanthin yield from coagulated wastewater in which microalgae were cultured was 3.26 mg/L, and total phosphorus and nitrogen contents decreased 99% ± 1% and 90% ± 8% (Days 31–35), respectively [corrected].

  11. Chlorella zofingiensis as an Alternative Microalgal Producer of Astaxanthin: Biology and Industrial Potential

    PubMed Central

    Liu, Jin; Sun, Zheng; Gerken, Henri; Liu, Zheng; Jiang, Yue; Chen, Feng

    2014-01-01

    Astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione), a high-value ketocarotenoid with a broad range of applications in food, feed, nutraceutical, and pharmaceutical industries, has been gaining great attention from science and the public in recent years. The green microalgae Haematococcus pluvialis and Chlorella zofingiensis represent the most promising producers of natural astaxanthin. Although H. pluvialis possesses the highest intracellular astaxanthin content and is now believed to be a good producer of astaxanthin, it has intrinsic shortcomings such as slow growth rate, low biomass yield, and a high light requirement. In contrast, C. zofingiensis grows fast phototrophically, heterotrophically and mixtrophically, is easy to be cultured and scaled up both indoors and outdoors, and can achieve ultrahigh cell densities. These robust biotechnological traits provide C. zofingiensis with high potential to be a better organism than H. pluvialis for mass astaxanthin production. This review aims to provide an overview of the biology and industrial potential of C. zofingiensis as an alternative astaxanthin producer. The path forward for further expansion of the astaxanthin production from C. zofingiensis with respect to both challenges and opportunities is also discussed. PMID:24918452

  12. Chlorella zofingiensis as an alternative microalgal producer of astaxanthin: biology and industrial potential.

    PubMed

    Liu, Jin; Sun, Zheng; Gerken, Henri; Liu, Zheng; Jiang, Yue; Chen, Feng

    2014-06-10

    Astaxanthin (3,3'-dihydroxy-β,β-carotene-4,4'-dione), a high-value ketocarotenoid with a broad range of applications in food, feed, nutraceutical, and pharmaceutical industries, has been gaining great attention from science and the public in recent years. The green microalgae Haematococcus pluvialis and Chlorella zofingiensis represent the most promising producers of natural astaxanthin. Although H. pluvialis possesses the highest intracellular astaxanthin content and is now believed to be a good producer of astaxanthin, it has intrinsic shortcomings such as slow growth rate, low biomass yield, and a high light requirement. In contrast, C. zofingiensis grows fast phototrophically, heterotrophically and mixtrophically, is easy to be cultured and scaled up both indoors and outdoors, and can achieve ultrahigh cell densities. These robust biotechnological traits provide C. zofingiensis with high potential to be a better organism than H. pluvialis for mass astaxanthin production. This review aims to provide an overview of the biology and industrial potential of C. zofingiensis as an alternative astaxanthin producer. The path forward for further expansion of the astaxanthin production from C. zofingiensis with respect to both challenges and opportunities is also discussed.

  13. Rapid liquid chromatographic method to distinguish wild salmon from aquacultured salmon fed synthetic astaxanthin.

    PubMed

    Turujman, S A; Wamer, W G; Wei, R R; Albert, R H

    1997-01-01

    Analytical methods are needed to determine the presence of color additives in fish. We report a liquid chromatographic (LC) method developed to identify the synthetic form of the color additive astaxanthin in salmon, based on differences in the relative ratios of the configurational isomers of astaxanthin. The distributions of configurational isomers of astaxanthin in the flesh of wild Atlantic and wild Pacific salmon are similar, but significantly different from that in aquacultured salmon. Astaxanthin is extracted from the flesh of salmon, passed through a silica gel Sep-Pak cartridge, and analyzed directly by LC on a Pirkle covalent L-leucine column. No derivatization of the astaxanthin is required-an important advantage of our approach, which is a modification of our previously described method. This method can be used to distinguish between aquacultured and wild salmon. The method has general applicability and can also be used to identify astaxanthins derived from other sources such as Phaffia yeast and Haematococcus pluvialis algae.

  14. Highly efficient biosynthesis of astaxanthin in Saccharomyces cerevisiae by integration and tuning of algal crtZ and bkt.

    PubMed

    Zhou, Pingping; Ye, Lidan; Xie, Wenping; Lv, Xiaomei; Yu, Hongwei

    2015-10-01

    Astaxanthin is a highly valued carotenoid with strong antioxidant activity and has wide applications in aquaculture, food, cosmetic, and pharmaceutical industries. The market demand for natural astaxanthin promotes research in metabolic engineering of heterologous hosts for astaxanthin production. In this study, an astaxanthin-producing Saccharomyces cerevisiae strain was created by successively introducing the Haematococcus pluvialis β-carotenoid hydroxylase (crtZ) and ketolase (bkt) genes into a previously constructed β-carotene hyperproducer. Further integration of strategies including codon optimization, gene copy number adjustment, and iron cofactor supplementation led to significant increase in the astaxanthin production, reaching up to 4.7 mg/g DCW in the shake-flask cultures which is the highest astaxanthin content in S. cerevisiae reported to date. Besides, the substrate specificity of H. pluvialis CrtZ and BKT and the probable formation route of astaxanthin from β-carotene in S. cerevisiae were figured out by expressing the genes separately and in combination. The yeast strains engineered in this work provide a basis for further improving biotechnological production of astaxanthin and might offer a useful general approach to the construction of heterologous biosynthetic pathways for other natural products.

  15. Optimization of protein electroextraction from microalgae by a flow process.

    PubMed

    Coustets, Mathilde; Joubert-Durigneux, Vanessa; Hérault, Josiane; Schoefs, Benoît; Blanckaert, Vincent; Garnier, Jean-Pierre; Teissié, Justin

    2015-06-01

    Classical methods, used for large scale treatments such as mechanical or chemical extractions, affect the integrity of extracted cytosolic protein by releasing proteases contained in vacuoles. Our previous experiments on flow processes electroextraction on yeasts proved that pulsed electric field technology allows preserving the integrity of released cytosolic proteins, by not affecting vacuole membranes. Furthermore, large cell culture volumes are easily treated by the flow technology. Based on this previous knowledge, we developed a new protocol in order to electro-extract total cytoplasmic proteins from microalgae (Nannochloropsis salina, Chlorella vulgaris and Haematococcus pluvialis). Given that induction of electropermeabilization is under the control of target cell size, as the mean diameter for N. salina is only 2.5 μm, we used repetitive 2 ms long pulses of alternating polarities with stronger field strengths than previously described for yeasts. The electric treatment was followed by a 24h incubation period in a salty buffer. The amount of total protein release was observed by a classical Bradford assay. A more accurate evaluation of protein release was obtained by SDS-PAGE. Similar results were obtained with C. vulgaris and H. pluvialis under milder electrical conditions as expected from their larger size.

  16. Growth, photosynthetic and respiratory responses to sub-lethal copper concentrations in Scenedesmus incrassatulus (Chlorophyceae).

    PubMed

    Perales-Vela, Hugo Virgilio; González-Moreno, Sergio; Montes-Horcasitas, Carmen; Cañizares-Villanueva, Rosa Olivia

    2007-05-01

    In the present paper we investigated the effects of sub-lethal concentrations of Cu2+ in the growth and metabolism of Scenedesmus incrassatulus. We found that the effect of Cu2+ on growth, photosynthetic pigments (chlorophylls and carotenoids) and metabolism do not follow the same pattern. Photosynthesis was more sensitive than respiration. The analysis of chlorophyll a fluorescence transient shows that the effect of sub-lethal Cu2+ concentration in vivo, causes a reduction of the active PSII reaction centers and the primary charge separation, decreasing the quantum yield of PSII, the electron transport rate and the photosynthetic O2 evolution. The order of sensitivity found was: Growth>photosynthetic pigments content=photosynthetic O2 evolution>photosynthetic electron transport>respiration. The uncoupled relationship between growth and metabolism is discussed.

  17. Phenotypic plasticity in Scenedesmus incrassatulus (Chlorophyceae) in response to heavy metals stress.

    PubMed

    Peña-Castro, Julián Mario; Martínez-Jerónimo, Fernando; Esparza-García, Fernando; Cañizares-Villanueva, Rosa Olivia

    2004-12-01

    The microalgae genus Scenedesmus is commonly found in freshwater bodies, wastewater facilities and water polluted with heavy metals. Phenotypic plasticity in Scenedesmus has been documented in response to a wide variety of conditions; however, heavy metals have not been comprehensively documented as phenotypic plasticity inducers. In this study, we report the phenotypic plasticity of Scenedesmus incrassatulus (a non-spiny, four-cell coenobium forming species) in response to EC(50) value of copper, cadmium and hexavalent chromium. S. incrassatulus was grown in batch cultures in the presence of each metal. Chlorophyll-a content, cell size, parameters derived from the schematic energy-flux model for photosystem II, and morphotype expressions were recorded. Divalent cation metals induced unicellular forms, and hexavalent chromium produced out-of-shape coenobia corresponding to various stages of autospore formation. The changes induced by divalent metals were interpreted as phenotypic plasticity, because they were always associated to population doublings and were reversible when toxicant pressure was removed (only for Cu). Copper was the best inductor of unicellular forms and also affected significantly all the photosynthetic parameters measured. The developed morphotypes could confer ecological advantages to S. incrassatulus in metal stressed environments.

  18. Characterization of rbcL group IA introns from two colonial volvocalean species (Chlorophyceae).

    PubMed

    Nozaki, H; Ohta, N; Yamada, T; Takano, H

    1998-05-01

    Group I introns were reported for the first time in the large subunit of Rubisco (rbcL) genes, using two colonial green algae, Pleodorina californica and Gonium multicoccum (Volvocales). The rbcL gene of P. californica contained an intron (PIC intron) of 1320 bp harboring an open reading frame (ORF). The G. multicoccum rbcL gene had two ORF-lacking introns of 549 (GM1 intron) and 295 (GM2 intron) base pairs. Based on the conserved nucleotide sequences of the secondary structure, the PIC and GM1 introns were assigned to group IA2 whereas the GM2 intron belonged to group IA1. Southern hybridization analyses of nuclear and chloroplast DNAs indicated that such intron-containing rbcL genes are located in the chloroplast genome. Sequencing RNAs from the two algae revealed that these introns are spliced out during mRNA maturation. In addition, the PIC and GM1 introns were inserted in the same position of the rbcL exons, and phylogenetic analysis of group IA introns indicated a close phylogenetic relationship between the PIC and GM1 introns within the lineage of bacteriophage group IA2 introns. However, P. californica and G. multicoccum occupy distinct clades in the phylogenetic trees of the colonial Volvocales, and the majority of other colonial volvocalean species do not have such introns in the rbcL genes. Therefore, these introns might have been recently inserted in the rbcL genes independently by horizontal transmission by viruses or bacteriophage.

  19. Optimization of culturing conditions for toxicity testing with the alga Oophila sp. (Chlorophyceae), an amphibian endosymbiont.

    PubMed

    Rodríguez-Gil, José Luis; Brain, Richard; Baxter, Leilan; Ruffell, Sarah; McConkey, Brendan; Solomon, Keith; Hanson, Mark

    2014-11-01

    Eggs of the yellow-spotted salamander (Ambystoma maculatum) have a symbiotic relationship with green algae. It has been suggested that contaminants that are preferentially toxic to algae, such as herbicides, may impair the symbiont and, hence, indirectly affect the development of the salamander embryo. To enable testing under near-standard conditions for first-tier toxicity screening, the authors isolated the alga from field-collected eggs and identified conditions providing exponential growth rates in the apparent asexual phase of the alga. This approach provided a uniform, single-species culture, facilitating assessment of common toxicity end points and comparison of sensitivity relative to other species. Sequencing of the 18s ribosomal DNA indicated that the isolated alga is closely related to the recently described Oophila amblystomatis but is more similar to other known Chlamydomonas species, suggesting possible biogeographical variability in the genetic identity of the algal symbiont. After a tiered approach to culturing method refinement, a modified Bristol's media with 1 mM NH4 (+) as nitrogen source was found to provide suitable conditions for toxicity testing at 18 °C and 200 µmol m(-2) s(-1) photosynthetically active radiation (PAR) on a 24-h light cycle. The validity of the approach was demonstrated with Zn(2+) as a reference toxicant. Overall, the present study shows that screening for direct effects of contaminants on the algal symbiont without the presence of the host salamander is possible under certain laboratory conditions. © 2014 SETAC.

  20. Chronological transition of mitochondrial morphology in Chlamydomonas reinhardtii (Chlorophyceae) poststationary phase growth(1).

    PubMed

    Aoyama, Hiroaki; Kuroiwa, Tsuneyoshi; Nakamura, Soichi

    2013-04-01

    In Chlamydomonas reinhardtii P. A. Dangeard, mitochondrial morphology has been observed during asexual cell division cycle, gamete and zygote formation, zygote maturation, and meiotic stages. However, the chronological transition of mitochondrial morphology after the stationary phase of vegetative growth, defined as the poststationary phase, remains unknown. Here, we examined the mitochondrial morphology in cells cultured for 4 months on agar plates to study mitochondrial dynamics in the poststationary phase. Fluorescence microscopy showed that the intricate thread-like structure of mitochondria gradually changed into a granular structure via fragmentation after the stationary phase in cultures of about 1 week of age. The number of mitochondrial nucleoids decreased from about 30 per cell at 1 week to about five per cell after 4 months of culture. The mitochondrial oxygen consumption decreased exponentially, but the mitochondria retained their membrane potential. The total quantity of mitochondrial DNA (mtDNA) of cells at 4 months decreased to 20% of that at 1 week. However, the mitochondrial genomic DNA length was unchanged, as intermediate lengths were not detected. In cells in which the total mtDNA amount was reduced artificially to 16% after treatment with 5-fluoro-2-deoxyuridine (FdUrd) for 1 week, the mitochondria remained as thread-like structures. The oxygen consumption rate of these cells corresponded to that of untreated cells at 1 week of culture. This suggests that a decrease in mtDNA does not directly induce the fragmentation of mitochondria. The results suggest that during the late poststationary phase, mitochondria converge to a minimum unit of a granular structure with a mitochondrial nucleoid. © 2013 Phycological Society of America.

  1. Characterization and expression analysis of hsp70 gene from Ulva prolifera J. Agardh (Chlorophycophyta, Chlorophyceae).

    PubMed

    Zhang, Haining; Li, Wei; Li, Jingjing; Fu, Wandong; Yao, Jianting; Duan, Delin

    2012-03-01

    In the Yellow Sea of China, large-scale green tides have broken out consecutively from 2007 to 2011. Ulva prolifera, the causative species of green tide, showed great ability to acclimate to adverse circumstance. To explore the mechanisms of rapid growth and stress resistance during the bloom, we characterized and analyzed hsp70 from U. prolifera. The results showed that hsp70 gene had 6 exons and 5 introns. The promoter-like region contained multiple cis-acting elements. The transcription of hsp70 was up-regulated by UV irradiation, heat treatment and salinities induction, but less influenced by desiccation. In vitro expression of HSP70 protein and western blot was also conducted, and the recombinant protein will be used in detecting the interaction between HSP70 and related functional proteins in the future. The study suggested that hsp70 could be used in prediction of stress tolerance in algae and monitoring environmental changes.

  2. Taxonomic revision of oil-producing green algae, Chlorococcum oleofaciens (Volvocales, Chlorophyceae), and its relatives.

    PubMed

    Kawasaki, Yuriko; Nakada, Takashi; Tomita, Masaru

    2015-10-01

    Historically, species in Volvocales were classified based primarily on morphology. Although the taxonomy of Chlamydomonas has been re-examined using a polyphasic approach including molecular phylogeny, that of Chlorococcum (Cc.), the largest coccoid genus in Volvocales, has yet to be reexamined. Six species thought to be synonymous with the oil-producing alga Cc. oleofaciens were previously not confirmed by molecular phylogeny. In this study, seven authentic strains of Cc. oleofaciens and its putative synonyms, along with 11 relatives, were examined based on the phylogeny of the 18S ribosomal RNA (rRNA) gene, comparisons of secondary structures of internal transcribed spacer 1 (ITS1) and ITS2 rDNA, and morphological observations by light microscopy. Seven 18S rRNA types were recognized among these strains and three were distantly related to Cc. oleofaciens. Comparisons of ITS rDNA structures suggested possible separation of the remaining four types into different species. Shapes of vegetative cells, thickness of the cell walls in old cultures, the size of cells in old cultures, and stigma morphology of zoospores also supported the 18S rRNA grouping. Based on these results, the 18 strains examined were reclassified into seven species. Among the putative synonyms, synonymy of Cc. oleofaciens, Cc. croceum, and Cc. granulosum was confirmed, and Cc. microstigmatum, Cc. rugosum, Cc. aquaticum, and Cc. nivale were distinguished from Cc. oleofaciens. Furthermore, another related strain is described as a new species, Macrochloris rubrioleum sp. nov.

  3. [Carotenogenesis of five strains of the algae Dunaliella sp. (Chlorophyceae) isolated from Venezuelan hypersaline lagoons].

    PubMed

    Guevara, Miguel; Lodeiros, César; Gómez, Olga; Lemus, Nathalie; Núñez, Paulino; Romero, Lolymar; Vásquez, Aléikar; Rosales, Néstor

    2005-01-01

    We evaluated discontinuous cultures (Algal medium at 0.5 mM of NaNO3, and 27% NaCI) of five strains of Dunaliella sp. isolated from Venezuelan hypersaline lagoons (Araya, Coche, Peonia, Cumaraguas. and Boca Chica) and one strain from a reference collection (Dunaliella salina, LB1644). Cultures were maintained to 25+/-1 degrees C, with constant aeration, photoperiod 12:12, and two light intensities (195 and 390 microE.m(-2).s(-1)) during 30 days. Cell count was recorded on a daily basis using a Neubaüer camera. Totals of chlorophyll a and carotenoids were measured at the end of the experiment. The largest cellular densities were measured during the smallest light intensities. The strain with the largest cellular density was isolated from Boca Chica (8 xl0(6) and 2.5 xl0(6) cel.ml(-1) a 390 and 195microE.m(-2).s(-1), respectively). The increment of light intensity produced a significant reduction of growth rates in all strains. Totals of carotenoids by volume were as large as 390 microE.m(-2).s(-1). Strains LB 1644, from Coche and Araya were those that produced the largest amount of carotenoids (38.4; 32.8 and 21.0 microg.ml(-1), respectively). Differences total carotenoids by cell between treatments were significant. The largest concentration was 390 microE.m(-2).s(-1). The strains LB 1644 and Coche produced the highest values of carotenes (137.14 and 106.06 pg.cel(-1), respectively). Differences in the relation carotenoid:chlorophyll a between the strains at various light intensities was significant. Strains LB1644 presented the largest value of the relation carotenoids:chlorophyll a (20:1) at 195 microE.m(-2).s(-1). No significant differences were detected in the strain Coche (15:1). All the other strains showed relations lower than one. Our results suggest that the strains of Coche and Araya show potential to be used in the biotechnology of carotenoids production.

  4. Delineating a New Heterothallic Species of Volvox (Volvocaceae, Chlorophyceae) Using New Strains of "Volvox africanus".

    PubMed

    Nozaki, Hisayoshi; Matsuzaki, Ryo; Yamamoto, Kayoko; Kawachi, Masanobu; Takahashi, Fumio

    2015-01-01

    The volvocine algae represent an excellent model lineage in which to study evolution of female and male genders based on comparative analyses of related species. Among these species, Volvox carteri has been extensively studied as a model of an oogamous and complex organism. However, it may have unique derived features that are not present in other species of Volvox. Therefore, information regarding the characteristics of sexual reproduction of other species of Volvox is also important. In 1971, Starr studied four types of sexuality in several global strains identified as Volvox africanus; however, further taxonomic studies of these strains have been lacking, and strains of three of the four sexual types are not available. Here, we studied the morphology, sexual reproduction, and taxonomy of two V. africanus-like species isolated recently from Lake Biwa, Japan. These two species were very similar to two sexual types described by Starr in 1971: one producing dioecious sexual spheroids in heterothallic strains and the other forming both male spheroids and monoecious spheroids in a single strain. The former species produced zygotes with a reticulate cell wall, whereas a smooth zygote wall was observed in the latter species as in V. africanus previously reported from various localities around the world. Our multigene phylogenetic analysis demonstrated that these are sister species to each other. However, the presence of a compensatory base change in the most conserved region of the secondary structure of nuclear ribosomal DNA internal transcribed spacer-2, hybrid inviability demonstrated by intercrossing experiments, and morphological differences in the density of abutment between the gelatinous material of adjacent cells (individual sheaths) in the spheroid supported the recognition of the two species, V. africanus having a smooth zygote wall and V. reticuliferus Nozaki sp. nov. having a reticulate zygote wall.

  5. A new record of the rare alga Pachycladella P. C. Silva (Chlorophyceae) in New England

    PubMed Central

    Fučíková, Karolina

    2015-01-01

    Abstract A rarely reported taxon, the microscopic green alga Pachycladella, was found in a pond in Connecticut. Due to an unresolved taxonomic debate within the genus, the species-level identity of the newly discovered population cannot be determined with absolute certainty. However, according to the currently accepted classification the Connecticut specimens best match Pachycladella zatoriensis, heretofore only known from Europe. The find represents not only the first record of Pachycladella in Connecticut, but also in the entire New England region. This study highlights the need for continuing floristic surveys even in regions previously well explored. PMID:26491383

  6. Flow Cytometric Methods for Indirect Analysis and Quantification of Gametogenesis in Chlamydomonas reinhardtii (Chlorophyceae)

    PubMed Central

    Tomkins, Joseph L.

    2016-01-01

    Induction of sexual reproduction in the facultatively sexual Chlamydomonas reinhardtii is cued by depletion of nitrogen. We explore the capacity for indirect monitoring of population variation in the gametogenic process using flow cytometry. We describe a high-throughput method capable of identifying fluorescence, ploidy and scatter profiles that track vegetative cells entering and undergoing gametogenesis. We demonstrate for the first time, that very early and late growth phases reduce the capacity to distinguish putative gametes from vegetative cells based on scatter and fluorescence profiles, and that early/mid-logarithmic cultures show the optimal distinction between vegetative cells and gamete scatter profiles. We argue that early/mid logarithmic cultures are valuable in such high throughput comparative approaches when investigating optimisation or quantification of gametogenesis based on scatter and fluorescence profiles. This approach provides new insights into the impact of culture conditions on gametogenesis, while documenting novel scatter and fluorescence profile shifts which typify the process. This method has potential applications to; enabling quick high-throughput monitoring, uses in increasing efficiency in the quantification of gametogenesis, as a method of comparing the switch between vegetative and gametic states across treatments, and as criteria for enrichment of gametic phenotypes in cell sorting assays. PMID:27676075

  7. Evolution of the ITS sequences of ribosomal DNA in Enteromorpha (Chlorophyceae).

    PubMed

    Leskinen, E; Pamilo, P

    1997-01-01

    Ribosomal DNA (rDNA) region, including the 3' end of the 18S rRNA gene, the entire 5.8S rRNA gene, the 5' end of the 28S rRNA gene, and the internal transcribed spacers ITS 1 and ITS 2, of Enteromorpha green algae from the Baltic Sea, were sequenced. The evolution of the Enteromorpha sequences differed from those of other green algae in several important ways. The ITS regions were short and had a high nucleotide bias. The frequency of nucleotides G and C was up to 70% in the ITS sequences, whereas the frequencies were close to 50% in the 5.8S rDNA. Furthermore, the sequence divergence was much higher in ITS 1 than in ITS 2. Two haplotypes, differing only by two nucleotides, were detected in the E. intestinalis/compressa complex. The difference coincides with a morphological differentiation (branching of thalli) and may represent distinct gene pools.

  8. Spectroscopic investigation of ionizing-radiation tolerance of a Chlorophyceae green micro-alga

    NASA Astrophysics Data System (ADS)

    Farhi, E.; Rivasseau, C.; Gromova, M.; Compagnon, E.; Marzloff, V.; Ollivier, J.; Boisson, A. M.; Bligny, R.; Natali, F.; Russo, D.; Couté, A.

    2008-03-01

    Micro-organisms living in extreme environments are captivating in the peculiar survival processes they have developed. Deinococcus radiodurans is probably the most famous radio-resistant bacteria. Similarly, a specific ecosystem has grown in a research reactor storage pool, and has selected organisms which may sustain radiative stress. An original green micro-alga which was never studied for its high tolerance to radiations has been isolated. It is the only autotrophic eukaryote that develops in this pool, although contamination possibilities coming from outside are not unusual. Studying what could explain this irradiation tolerance is consequently very interesting. An integrative study of the effects of irradiation on the micro-algae physiology, metabolism, internal dynamics, and genomics was initiated. In the work presented here, micro-algae were stressed with irradiation doses up to 20 kGy (2 Mrad), and studied by means of nuclear magnetic resonance, looking for modifications in the metabolism, and on the IN13 neutron backscattering instrument at the ILL, looking for both dynamics and structural macromolecular changes in the cells.

  9. AN OPTIMIZED METHOD FOR THE ISOLATION OF NUCLEI FROM CHLAMYDOMONAS REINHARDTII (CHLOROPHYCEAE)(1).

    PubMed

    Winck, Flavia Vischi; Kwasniewski, Miroslaw; Wienkoop, Stefanie; Mueller-Roeber, Bernd

    2011-04-01

    The cell nucleus harbors a large number of proteins involved in transcription, RNA processing, chromatin remodeling, nuclear signaling, and ribosome assembly. The nuclear genome of the model alga Chlamydomonas reinhardtii P. A. Dang. was recently sequenced, and many genes encoding nuclear proteins, including transcription factors and transcription regulators, have been identified through computational discovery tools. However, elucidating the specific biological roles of nuclear proteins will require support from biochemical and proteomics data. Cellular preparations with enriched nuclei are important to assist in such analyses. Here, we describe a simple protocol for the isolation of nuclei from Chlamydomonas, based on a commercially available kit. The modifications done in the original protocol mainly include alterations of the differential centrifugation parameters and detergent-based cell lysis. The nuclei-enriched fractions obtained with the optimized protocol show low contamination with mitochondrial and plastid proteins. The protocol can be concluded within only 3 h, and the proteins extracted can be used for gel-based and non-gel-based proteomic approaches. © 2011 Phycological Society of America.

  10. A NEW SPECIES OF VOLVOX SECT. MERRILLOSPHAERA (VOLVOCACEAE, CHLOROPHYCEAE) FROM TEXAS(1).

    PubMed

    Nozaki, Hisayoshi; Coleman, Annette W

    2011-06-01

    Smith (1944) divided the familiar genus Volvox L. into four sections, placing seven species that lacked cytoplasmic bridges between adult cells in the section Merrillosphaera. Herein, we describe a new member of the section Merrillosphaera originating from Texas (USA): Volvox ovalis Pocock ex Nozaki et A. W. Coleman sp. nov. Asexual spheroids of V. ovalis are ovoid or elliptical, with a monolayer of 1,000-2,000 somatic cells that are not linked by cytoplasmic bridges, an expanded anterior region, and 8-12 gonidia in the posterior region. Visibly asymmetric cleavage divisions do not occur in V. ovalis embryos as they do Volvox carteri F. Stein, Volvox obversus (W. Shaw) Printz, and Volvox africanus G. S. West, so the gonidia of the next generation are not yet recognizable in V. ovalis embryos prior to inversion. Molecular phylogenetic analyses of the five chloroplast genes and the internal transcribed spacer (ITS) regions of nuclear rDNA indicated that V. ovalis is closely related to Volvox spermatosphaera Powers (Powers 1908, as "spermatosphara") and/or Volvox tertius Art. Mey.; however, V. ovalis can be distinguished from V. spermatosphaera by its larger gonidia, and from V. tertius by visible differences in gonidial chloroplast morphology.

  11. Phylogeny of chloromonas (chlorophyceae): A study of 18S ribosomal RNA gene sequences

    SciTech Connect

    Buchheim, M.A.; Buchheim, J.A.; Chapman, R.L.

    1997-04-01

    The unicellular, biflagellate genus Chloromonas differs from its ally, Chlamydomonas, primarily by the absence of pyrenoids in the vegetative stage of the former. As with most green flagellate genera, little is known about phylogenetic affinities within and among Chloromonas species. Phylogenetic analyses of nuclear-encoded small-subunit ribosomal RNA gene sequences demonstrate that a sampling of five Chloromonas taxa, obtained from major culture collections, do not form a monophyletic group. However, only three of these isolates, Chloromonas clathrata, Chloromonas serbinowi, and Chloromonas rosae, are diagnosable morphologically as Chloromonas species by the absence of a pyrenoid in the vegetative stage. The three diagnosable Chloromonas taxa form an alliance with two pyrenoid-bearing chlamydomonads, Chlamydomonas augustae and Chlamydomonas macrostellata. With the exception of Chloromonas serbinowi, which represents the basal lineage within the clade, each of the diagnosable Chloromonas taxa and their pyrenoid-bearing Chlamydomonas allies were isolated originally from mountain soils, snow, or cold peat. These observations suggest that hibitat, independent of pyrenoid status, may be most closely linked to the natural history of this clade of chlamydomonad flagellates. 51 refs., 3 figs., 3 tabs.

  12. Effects of the antibiotics penicillin, streptomycin, and tetracycline on the karyology of Oedogonium gunnii Wittr. (Chlorophyceae).

    PubMed

    Srivastava, S; Sarma, Y S

    1980-01-01

    Effects of penicillin, streptomycin and tetracycline were seen on the karyology of a filamentous green alga, Oedogonium gunnii Wittr. Various nuclear and chromosomal aberrations such as, fragmentation of the chromosomes, extreme clumping and unequal groupings of the chromosomes, vacuolization of nuclei and nucleoli, and irregular anaphase chromatid breaks, were observed in the materials treated with 500 and 750 micrograms/ml streptomycin, and 250 and 500 micrograms/ml tetracycline, and which, however, were not seen with any of the concentrations of penicillin employed. With lower concentrations of the three antibiotics given continuously for longer duration, several aberrations were observed. The frequency of the aberrations did not seem to follow a regular pattern and varied with each antibiotic and the duration of treatment.

  13. Effects of non-steroidal anti-inflammatory drugs on cyanobacteria and algae in laboratory strains and in natural algal assemblages.

    PubMed

    Bácsi, István; B-Béres, Viktória; Kókai, Zsuzsanna; Gonda, Sándor; Novák, Zoltán; Nagy, Sándor Alex; Vasas, Gábor

    2016-05-01

    In recent years measurable concentrations of non-steroidal anti-inflammatory drugs (NSAIDs) have been shown in the aquatic environment as a result of increasing human consumption. Effects of five frequently used non-steroidal anti-inflammatory drugs (diclofenac, diflunisal, ibuprofen, mefenamic acid and piroxicam in 0.1 mg ml(-1) concentration) in batch cultures of cyanobacteria (Synechococcus elongatus, Microcystis aeruginosa, Cylindrospermopsis raciborskii), and eukaryotic algae (Desmodesmus communis, Haematococcus pluvialis, Cryptomonas ovata) were studied. Furthermore, the effects of the same concentrations of NSAIDs were investigated in natural algal assemblages in microcosms. According to the changes of chlorophyll-a content, unicellular cyanobacteria seemed to be more tolerant to NSAIDs than eukaryotic algae in laboratory experiments. Growth of eukaryotic algae was reduced by all drugs, the cryptomonad C. ovata was the most sensitive to NSAIDs, while the flagellated green alga H. pluvialis was more sensitive than the non-motile green alga D. communis. NSAID treatments had weaker impact in the natural assemblages dominated by cyanobacteria than in the ones dominated by eukaryotic algae, confirming the results of laboratory experiments. Diversity and number of functional groups did not change notably in cyanobacteria dominated assemblages, while they decreased significantly in eukaryotic algae dominated ones compared to controls. The results highlight that cyanobacteria (especially unicellular ones) are less sensitive to the studied, mostly hardly degradable NSAIDs, which suggest that their accumulation in water bodies may contribute to the expansion of cyanobacterial mass productions in appropriate environmental circumstances by pushing back eukaryotic algae. Thus, these contaminants require special attention during wastewater treatment and monitoring of surface waters.

  14. Safety assessment of astaxanthin-rich microalgae biomass: Acute and subchronic toxicity studies in rats.

    PubMed

    Stewart, John S; Lignell, Ake; Pettersson, Annette; Elfving, Elisabeth; Soni, M G

    2008-09-01

    Astaxanthin, a natural nutritional component, is marketed as a dietary supplement around the world. The primary commercial source for astaxanthin is Haematococcus pluvialis (microalgae). The objective of the present study was to investigate the acute and subchronic toxicity of an astaxanthin-rich biomass of H. pluvialis (AstaCarox). The oral LD(50) of the biomass in rats was greater than 12g/kg body weight. In the subchronic study, Wistar rats (10/sex/group) were fed diets containing 0%, 1%, 5% and 20% of the biomass (weight/weight) for 90 days. trans-Astaxanthin was quantifiable in the plasma of the high-dose treated group only. Compared to the control group, no treatment-related biologically significant effects of astaxanthin were noted on body weight or body weight gain. Biomass feeding did not affect hematological parameters. In the high-dose group, slightly elevated alkaline phosphatase and changes in some urine parameters and an increase in kidney weight in both sexes were noted. Histopathology examinations did not reveal adverse effects except for a marginal increase in pigment in the straight proximal tubule of the kidney in 5/10 female rats treated with the high-dose. These changes were not considered as toxicologically significant. Although the rats in high-dose group received about 9% more fat, it is unlikely that this confounding factor significantly altered the outcome. The no-observed adverse-effect-levels (NOAEL) of the astaxanthin-rich biomass for male and female rats were determined as 14,161 and 17,076mg/kg body weight/day, or 465 and 557mg astaxanthin/kg/day, respectively, the highest dose tested.

  15. Development of thin-film photo-bioreactor and its application to outdoor culture of microalgae.

    PubMed

    Yoo, Jae Jun; Choi, Seung Phill; Kim, Jaoon Y H; Chang, Won Seok; Sim, Sang Jun

    2013-06-01

    Photosynthetic microalgae have received much attention as a microbial source of diverse useful biomaterials through CO(2) fixation and various types of photo-bioreactors have been developed for efficient microalgal cultivation. Herein, we developed a novel thin-film photo-bioreactor, which was made of cast polypropylene film, considering outdoor mass cultivation. To develop optimal design of photo-bioreactor, we tested performance of three shapes of thin-film photo-bioreactors (flat, horizontal and vertical tubular shapes) and various parts in the bioreactor. Collectively, vertical tubular bioreactor with H/D ratio 6:1 and cylindrical stainless steel spargers showed the most outstanding performance. Furthermore, the photo-bioreactor was successfully applied to the cultivation of other microalgae such as Chlamydomonas reinhardtii and Chlorella vulgaris. The scalability of photo-bioreactor was confirmed by gradually increasing culture volume from 4 to 25 L and the biomass productivity of each reactor was quite consistent (0.05-0.07 g/L/day) during the cultivation of H. pluvialis under indoor and outdoor conditions. Especially, we also achieved dry cell weight of 4.64 g/L and astaxanthin yield of 218.16 mg/L through long-term cultivation (100 days) under outdoor condition in 15 L photo-bioreactor using Haematococcus pluvialis, which means that the astaxanthin yield from outdoor cultivation is equal or superior to that obtained from controlled indoor condition. Therefore, these results indicate that we can apply this approach to development of optimal photo-bioreactor for the large-scale culture of microalgae and production of useful biomaterials under outdoor condition.

  16. Effect of Diets Supplemented with Different Sources of Astaxanthin on the Gonad of the Sea Urchin Anthocidaris crassispina

    PubMed Central

    Peng, Juan; Yuan, Jian-Ping; Wang, Jiang-Hai

    2012-01-01

    The effect of the microalgae Haematococcus pluvialis and Chorella zofingiensis, and synthetic astaxanthin on the gonad of the sea urchin Anthocidaris crassispina was studied. The basal diet was supplemented with H. pluvialis, C. zofingiensis, or synthetic astaxanthin, at two levels of astaxanthin (approximately 400 mg/kg and 100 mg/kg), to obtain the experimental diets HP1, HP2, CZ1, CZ2, AST1, and AST2, respectively, for two months of feeding experiment. The results showed that the concentrations of astaxanthin in the gonads of the sea urchins fed these experimental diets ranged from 0.15 to 3.01 mg/kg dry gonad weight. The higher astaxanthin levels (>2.90 mg/kg) were found in the gonads of the sea urchins fed the diets HP1 (containing 380 mg/kg of astaxanthins, mostly mono- and diesters) and AST1 (containing 385 mg/kg of synthetic astaxanthin). The lowest astaxanthin level (0.15 mg/kg) was detected in the gonads of the sea urchins fed the diet CZ2 (containing 98 mg/kg of astaxanthins, mostly diesters). Furthermore, the highest canthaxanthin level (7.48 mg/kg) was found in the gonads of the sea urchins fed the diet CZ1 (containing 387 mg/kg of astaxanthins and 142 mg/kg of canthaxanthin), suggesting that astaxanthins, especially astaxanthin esters, might not be assimilated as easily as canthaxanthin by the sea urchins. Our results show that sea urchins fed diets containing astaxanthin pigments show higher incorporation of these known antioxidant constituents, with the resultant seafood products therefore being of potential higher nutritive value. PMID:23016124

  17. Carotenoid and fatty acid compositions of an indigenous Ettlia texensis isolate (Chlorophyceae) under phototrophic and mixotrophic conditions.

    PubMed

    Yıldırım, Arzu; Demirel, Zeliha; İşleten-Hoşoğlu, Müge; Akgün, İsmail Hakkı; Hatipoğlu-Uslu, Sevde; Conk-Dalay, Meltem

    2014-02-01

    Ettlia oleoabundance (formerly known as Neochloris oleoabundance) is an attractive candidate for biodiesel production because of its high lipid accumulation, and it's taking the majority of the attention among the strains of Ettlia genus; however, potential of the other genus members is unknown. An indigenous strain from Salda Lake (South West Turkey) identified by 18S rDNA sequencing as Ettlia texensis (GenBank accession no: JQ038221), and its fatty acid and carotenoid compositions under phototrophic and mixotrophic conditions was investigated to evaluate the potential of the strain for commercial uses. A threefold increase was observed in total lipid content (total fatty acids; from 13% to 37%) in mixotrophic culture respect to the phototrophic growth conditions. The oleic acid (C18:1) and alpha-linolenic acid (18:3) were the major unsaturated fatty acids accounting for 40% and 13.2% of total fatty acids in mixotrophic culture, respectively. Carotenoid analyses of the mixotrophic culture revealed the metabolite canthaxanthin, a commercially valuable carotenoid used mainly for food coloring, was the major constituent among other pigments. The possible use of E. texensis in biotechnological applications is discussed.

  18. Nucleotide diversity of the colorless green alga Polytomella parva (Chlorophyceae, Chlorophyta): high for the mitochondrial telomeres, surprisingly low everywhere else.

    PubMed

    Smith, David Roy; Lee, Robert W

    2011-01-01

    Silent-site nucleotide diversity data (π(silent)) can provide insights into the forces driving genome evolution. Here we present π(silent) statistics for the mitochondrial and nuclear DNAs of Polytomella parva, a nonphotosynthetic green alga with a highly reduced, linear fragmented mitochondrial genome. We show that this species harbors very little genetic diversity, with the exception of the mitochondrial telomeres, which have an excess of polymorphic sites. These data are compared with previously published π(silent) values from the mitochondrial and nuclear genomes of the model species Chlamydomonas reinhardtii and Volvox carteri, which are close relatives of P. parva, and are used to understand the modes and tempos of genome evolution within green algae.

  19. Chloroplast phylogenomic data from the green algal order Sphaeropleales (Chlorophyceae, Chlorophyta) reveal complex patterns of sequence evolution.

    PubMed

    Fučíková, Karolina; Lewis, Paul O; Lewis, Louise A

    2016-05-01

    Chloroplast sequence data are widely used to infer phylogenies of plants and algae. With the increasing availability of complete chloroplast genome sequences, the opportunity arises to resolve ancient divergences that were heretofore problematic. On the flip side, properly analyzing large multi-gene data sets can be a major challenge, as these data may be riddled with systematic biases and conflicting signals. Our study contributes new data from nine complete and four fragmentary chloroplast genome sequences across the green algal order Sphaeropleales. Our phylogenetic analyses of a 56-gene data set show that analyzing these data on a nucleotide level yields a well-supported phylogeny - yet one that is quite different from a corresponding amino acid analysis. We offer some possible explanations for this conflict through a range of analyses of modified data sets. In addition, we characterize the newly sequenced genomes in terms of their structure and content, thereby further contributing to the knowledge of chloroplast genome evolution.

  20. Multiple ice-binding proteins of probable prokaryotic origin in an Antarctic lake alga, Chlamydomonas sp. ICE-MDV (Chlorophyceae).

    PubMed

    Raymond, James A; Morgan-Kiss, Rachael

    2017-08-01

    Ice-associated algae produce ice-binding proteins (IBPs) to prevent freezing damage. The IBPs of the three chlorophytes that have been examined so far share little similarity across species, making it likely that they were acquired by horizontal gene transfer (HGT). To clarify the importance and source of IBPs in chlorophytes, we sequenced the IBP genes of another Antarctic chlorophyte, Chlamydomonas sp. ICE-MDV (Chlamy-ICE). Genomic DNA and total RNA were sequenced and screened for known ice-associated genes. Chlamy-ICE has as many as 50 IBP isoforms, indicating that they have an important role in survival. The IBPs are of the DUF3494 type and have similar exon structures. The DUF3494 sequences are much more closely related to prokaryotic sequences than they are to sequences in other chlorophytes, and the chlorophyte IBP and ribosomal 18S phylogenies are dissimilar. The multiple IBP isoforms found in Chlamy-ICE and other algae may allow the algae to adapt to a greater variety of ice conditions than prokaryotes, which typically have a single IBP gene. The predicted structure of the DUF3494 domain has an ice-binding face with an orderly array of hydrophilic side chains. The results indicate that Chlamy-ICE acquired its IBP genes by HGT in a single event. The acquisitions of IBP genes by this and other species of Antarctic algae by HGT appear to be key evolutionary events that allowed algae to extend their ranges into polar environments. © 2017 Phycological Society of America.

  1. Photobioreactor cultivation and catalytic pyrolysis of the microalga Desmodesmus communis (Chlorophyceae) for hydrocarbons production by HZSM-5 zeolite cracking.

    PubMed

    Conti, Roberto; Pezzolesi, Laura; Pistocchi, Rossella; Torri, Cristian; Massoli, Patrizio; Fabbri, Daniele

    2016-12-01

    The study evaluated the growth of Desmodesmus communis on column photobioreactor and its thermochemical treatment by catalytic pyrolysis using HZSM-5 zeolite. D. communis showed good results in terms of growth (0.05gL(-1)d(-1)). Analytical pyrolysis of original algae and derived bio-oil mixed with zeolite was used as a screening method in order to gather information on the cracking process. Preparative pyrolysis on bench scale reactor was performed on algae biomass over a zeolite bed at 1:10 ratio (wt/wt). Py-GC-MS of biomass/catalyst mixture showed that the denitrogenation/deoxygenation increased with increasing zeolite load from 1:5 to 1:20 ratio and became significant at 1:10 ratio. The composition observed by analytical pyrolysis was featured by the predominance of alkylated monoaromatic hydrocarbons. The scaling-up to bench scale confirmed the results obtained with analytical pyrolysis in terms of monoaromatic hydrocarbons. However, low yield of catalytic oil (8% by weight) was observed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. How DNA barcoding can be more effective in microalgae identification: a case of cryptic diversity revelation in Scenedesmus (Chlorophyceae)

    PubMed Central

    Zou, Shanmei; Fei, Cong; Wang, Chun; Gao, Zhan; Bao, Yachao; He, Meilin; Wang, Changhai

    2016-01-01

    Microalgae identification is extremely difficult. The efficiency of DNA barcoding in microalgae identification involves ideal gene markers and approaches employed, which however, is still under the way. Although Scenedesmus has obtained much research in producing lipids its identification is difficult. Here we present a comprehensive coalescent, distance and character-based DNA barcoding for 118 Scenedesmus strains based on rbcL, tufA, ITS and 16S. The four genes, and their combined data rbcL + tufA + ITS + 16S, rbcL + tufA and ITS + 16S were analyzed by all of GMYC, P ID, PTP, ABGD, and character-based barcoding respectively. It was apparent that the three combined gene data showed a higher proportion of resolution success than the single gene. In comparison, the GMYC and PTP analysis produced more taxonomic lineages. The ABGD generated various resolution in discrimination among the single and combined data. The character-based barcoding was proved to be the most effective approach for species discrimination in both single and combined data which produced consistent species identification. All the integrated results recovered 11 species, five out of which were revealed as potential cryptic species. We suggest that the character-based DNA barcoding together with other approaches based on multiple genes and their combined data could be more effective in microalgae diversity revelation. PMID:27827440

  3. Cryopreservation of economically valuable marine micro-algae in the classes Bacillariophyceae, Chlorophyceae, Cyanophyceae, Dinophyceae, Haptophyceae, Prasinophyceae, and Rhodophyceae.

    PubMed

    Rhodes, Lesley; Smith, John; Tervit, Robin; Roberts, Rodney; Adamson, Janet; Adams, Serean; Decker, Marie

    2006-02-01

    The ability to routinely cryopreserve micro-algal species reduces costs associated with maintaining large culture collections and reduces the risks of losing particular strains or species through contamination and genetic drift. Cryopreservation is also a useful adjunct in aquaculture hatcheries for strains of micro-algae where the nutritional status may change as a result of continuous sub-culture. In this study, cryopreservation of isolates from seven micro-algal classes was investigated. Successful candidates included the marine dinoflagellates Amphidinium carterae, Amphidinium trulla, and Gymnodinium simplex, and the haptophytes Chrysochromulina simplex, Prymnesium parvum, Prymnesium parvum f. patelliferum, Isochrysis galbana, and Pavlova lutheri. Also successfully cryopreserved were the planktonic diatoms Chaetoceros calcitrans, Chaetoceros muelleri, Chaetoceros sp., and the benthic Nitzschia ovalis, the chlorophyte Chlamydomonas coccoides, the rhodophyte Porphyridium purpureum, the prasinophytes Tetraselmis chuii, and Tetraselmis suecica, and the cyanophytes Raphidiopsis sp., and Aphanizomenon flos-aquae. All species were successfully cryopreserved using 15% Me2SO.

  4. Morphology and phylogeny of a new wall-less freshwater volvocalean flagellate, Hapalochloris nozakii gen. et sp. nov. (Volvocales, Chlorophyceae).

    PubMed

    Nakada, Takashi; Tomita, Masaru

    2016-10-21

    New strains of a wall-less unicellular volvocalean flagellate were isolated from a freshwater environment in Japan. Observations of the alga, described here as Hapalochloris nozakii Nakada, gen. et sp. nov., were made using light, fluorescence, and electron microscopy. Each vegetative cell had two flagella, four contractile vacuoles, and a spirally furrowed cup-shaped chloroplast with an axial pyrenoid, and mitochondria located in the furrows. Based on the morphology, H. nozakii was distinguished from other known wall-less volvocalean flagellates. Under electron microscopy, fibrous material, instead of a cell wall and dense cortical microtubules, was observed outside and inside the cell membrane, respectively. Based on the phylogenetic analyses of 18S rRNA gene sequences, H. nozakii was found to be closely related to Asterococcus, Oogamochlamys, Rhysamphichloris, and "Dunaliella" lateralis and was separated from other known wall-less flagellate volvocaleans, indicating independent secondary loss of the cell wall in H. nozakii. In the combined 18S rRNA and chloroplast gene tree, H. nozakii was sister to Lobochlamys.

  5. Assessment of key biological and engineering design parameters for production of Chlorella zofingiensis (Chlorophyceae) in outdoor photobioreactors.

    PubMed

    Zemke, Peter E; Sommerfeld, Milton R; Hu, Qiang

    2013-06-01

    For the design of a large field of vertical flat plate photobioreactors (PBRs), the effect of four design parameters-initial biomass concentration, optical path length, spacing, and orientation of PBRs-on the biochemical composition and productivity of Chlorella zofingiensis was investigated. A two-stage batch process was assumed in which inoculum is generated under nitrogen-sufficient conditions, followed by accumulation of lipids and carbohydrates in nitrogen-deplete conditions. For nitrogen-deplete conditions, productivity was the most sensitive to initial biomass concentration, as it affects the light availability to individual cells in the culture. An initial areal cell concentration of 50 g m(-2) inoculated into 3.8-cm optical path PBR resulted in the maximum production of lipids (2.42 ± 0.02 g m(-2) day(-1)) and carbohydrates (3.23 ± 0.21 g m(-2) day(-1)). Productivity was less sensitive to optical path length. Optical path lengths of 4.8 and 8.4 cm resulted in similar areal productivities (biomass, carbohydrate, and lipid) that were 20 % higher than a 2.4-cm optical path length. Under nitrogen-sufficient conditions, biomass productivity was 48 % higher in PBRs facing north-south during the winter compared to east-west, but orientation had little influence on biomass productivity during the spring and summer despite large differences in insolation. An optimal spacing could not be determined based on growth alone because a tradeoff was observed in which volumetric and PBR productivity increased as space between PBRs increased, but land productivity decreased.

  6. Structure and chemistry of a new chemical race of Botryococcus braunii (chlorophyceae) that produces lycopadiene, a tetraterpenoid hydrocarbon

    SciTech Connect

    Metzger, P.; Allard, B.; Casadevall, E. ); Berkaloff, C.; Coute, A. )

    1990-06-01

    New strains of the hydrocarbon rich alga Botryococcus braunii Kuetzing were isolated from water samples collected in three tropical freshwater lakes. These strains synthesize lycopadiene, a tetraterpenoid metabolite, as their sole hydrocarbon. The morphological and ultrastructural characteristics of these algae are similar to those reported for previously described strains which produce either alkadienes or botryococcenes. The pyriform shaped cells are embedded in a colonial matrix formed by layers of closely appressed external walls; this dense matrix is impregnated by the hydrocarbon and some other lipids. We believe the new strains synthesizing lycopadiene form a third chemical race in B. braunii, besides the alkadiene and botryococcene races, rather than a different species. Like the other two types of hydrocarbons, lycopadiene was produced primarily during the exponential and linear growth phases. The major fatty acid in the three races was oleic acid. This fatty acid was predominant in the alkadiene race; palmitic and octacosenoic acid also were present in appreciable amounts in the three races. Cholest-5-en-3{beta}-ol, 24-methylcholest-5-en-3{beta}-ol and 24-ethylcholest-5-en-3{beta}-ol occurred in the three races; three unidentified sterols also were detected in the lycopadiene race. Moreover, the presence of very long chain alkenyl-phenols in the lipids of algae of the alkadiene race was not observed in the botryococcene and lycopadiene races. Of the polysaccharides released in the medium, galactose appeared as a primary component: it predominated in the botryococcene race. The other major constituents were fucose for the alkadiene race and glucose and fucose for the lycopadiene race.

  7. Delineating a New Heterothallic Species of Volvox (Volvocaceae, Chlorophyceae) Using New Strains of “Volvox africanus”

    PubMed Central

    Nozaki, Hisayoshi; Matsuzaki, Ryo; Yamamoto, Kayoko; Kawachi, Masanobu; Takahashi, Fumio

    2015-01-01

    The volvocine algae represent an excellent model lineage in which to study evolution of female and male genders based on comparative analyses of related species. Among these species, Volvox carteri has been extensively studied as a model of an oogamous and complex organism. However, it may have unique derived features that are not present in other species of Volvox. Therefore, information regarding the characteristics of sexual reproduction of other species of Volvox is also important. In 1971, Starr studied four types of sexuality in several global strains identified as Volvox africanus; however, further taxonomic studies of these strains have been lacking, and strains of three of the four sexual types are not available. Here, we studied the morphology, sexual reproduction, and taxonomy of two V. africanus-like species isolated recently from Lake Biwa, Japan. These two species were very similar to two sexual types described by Starr in 1971: one producing dioecious sexual spheroids in heterothallic strains and the other forming both male spheroids and monoecious spheroids in a single strain. The former species produced zygotes with a reticulate cell wall, whereas a smooth zygote wall was observed in the latter species as in V. africanus previously reported from various localities around the world. Our multigene phylogenetic analysis demonstrated that these are sister species to each other. However, the presence of a compensatory base change in the most conserved region of the secondary structure of nuclear ribosomal DNA internal transcribed spacer-2, hybrid inviability demonstrated by intercrossing experiments, and morphological differences in the density of abutment between the gelatinous material of adjacent cells (individual sheaths) in the spheroid supported the recognition of the two species, V. africanus having a smooth zygote wall and V. reticuliferus Nozaki sp. nov. having a reticulate zygote wall. PMID:26562165

  8. Effects of elevated pCO2 on physiological performance of marine microalgae Dunaliella salina (Chlorophyta, Chlorophyceae)

    NASA Astrophysics Data System (ADS)

    Hu, Shunxin; Wang, You; Wang, Ying; Zhao, Yan; Zhang, Xinxin; Zhang, Yongsheng; Jiang, Ming; Tang, Xuexi

    2017-06-01

    The present study was conducted to determine the effects of elevated pCO2 on growth, photosynthesis, dark respiration and inorganic carbon acquisition in the marine microalga Dunaliella salina. To accomplish this, D. salina was incubated in semi-continuous cultures under present-day CO2 levels (390 μatm, pHNBS: 8.10), predicted year 2100 CO2 levels (1 000 μatm, pHNBS: 7.78) and predicted year 2300 CO2 levels (2 000 μatm, pHNBS: 7.49). Elevated pCO2 significantly enhanced photosynthesis (in terms of gross photosynthetic O2 evolution, effective quantum yield (ΔF/F' m ), photosynthetic efficiency (α), maximum relative electron transport rate (rETRmax) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity) and dark respiration of D. salina, but had insignificant effects on growth. The photosynthetic O2 evolution of D. salina was significantly inhibited by the inhibitors acetazolamide (AZ), ethoxyzolamide (EZ) and 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS), indicating that D. salina is capable of acquiring HCO3 - via extracellular carbonic anhydrase and anion-exchange proteins. Furthermore, the lower inhibition of the photosynthetic O2 evolution at high pCO2 levels by AZ, EZ and DIDS and the decreased carbonic anhydrase showed that carbon concentrating mechanisms were down-regulated at high pCO2. In conclusion, our results show that photosynthesis, dark respiration and CCMs will be affected by the increased pCO2/low pH conditions predicted for the future, but that the responses of D. salina to high pCO2/low pH might be modulated by other environmental factors such as light, nutrients and temperature. Therefore, further studies are needed to determine the interactive effects of pCO2, temperature, light and nutrients on marine microalgae.

  9. Effect of temperature and irradiance on the growth and reproduction of Enteromorpha prolifera J. Ag. (Chlorophycophyta, Chlorophyceae)

    NASA Astrophysics Data System (ADS)

    Fu, Gang; Yao, Jianting; Liu, Fuli; Liu, Jidong; Wang, Xiuliang; Fu, Wandong; Li, Dapeng; Zhou, Mingjiang; Sun, Song; Duan, Delin

    2008-11-01

    Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate (SGR) of 10.47 at 25°C/40 μmol m-2s-1. Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 μm in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative cells could still divide actively in the algal tissues.

  10. In Vitro Effects of Some Botanicals with Anti-Inflammatory and Antitoxic Activity

    PubMed Central

    Guidetti, Gianandrea; Giovazzino, Angela; Rubino, Valentina; Palatucci, Anna Teresa; Centenaro, Sara; Fraccaroli, Elena; Cortese, Laura; Bonomo, Maria Grazia; Ruggiero, Giuseppina; Canello, Sergio; Terrazzano, Giuseppe

    2016-01-01

    Several extrinsic factors, like drugs and chemicals, can foster autoimmunity. Tetracyclines, in particular oxytetracycline (OTC), appear to correlate with the emergence of immune-mediated diseases. Accumulation of OTC, the elective drug for gastrointestinal and respiratory infectious disease treatment in broiler chickens, was reported in chicken edible tissues and could represent a potential risk for pets and humans that could assume this antibiotic as residue in meat or in meat-derived byproducts. We investigated the in vitro anti-inflammatory properties of a pool of thirteen botanicals as a part of a nutraceutical diet, with proven immunomodulatory activity. In addition, we evaluated the effect of such botanicals in contrasting the in vitro proinflammatory toxicity of OTC. Our results showed a significant reduction in interferon- (INF-) γ production by human and canine lymphocytes in presence of botanicals (⁎p < 0.05). Increased INF-γ production, dependent on 24-hour OTC-incubation of T lymphocytes, was significantly reduced by the coincubation with Haematococcus pluvialis, with Glycine max, and with the mix of all botanicals (⁎p < 0.05). In conclusion, the use of these botanicals was shown to be able to contrast OTC-toxicity and could represent a new approach for the development of functional foods useful to enhance the standard pharmacological treatment in infections as well as in preventing or reducing the emergence of inflammatory diseases. PMID:27597982

  11. Antioxidative activities of algal keto carotenoids acting as antioxidative protectants in the chloroplast.

    PubMed

    Dambeck, Michael; Sandmann, Gerhard

    2014-01-01

    Very diverse carotenoid structures exist in the photosynthesis apparatus of different algae. Among them, the keto derivatives are regarded the most antioxidative. Therefore, four different keto carotenoids, peridinin, fucoxanthin, siphonaxanthin and astaxanthin fatty acid monoesters, were isolated and purified from Amphidinium carterae, Phaeodactylum tricornutum, Caulerpa taxifolia and Haematococcus pluvialis, respectively. The carotenoids were assayed as inhibitors of photosensitizer initiated reactions or scavengers of radicals in the early events generating reactive oxygen species as starters for peroxidation and as protectants against the whole reaction chain finally leading to lipid peroxidation. These in vitro studies demonstrated the substantial antioxidative properties as indicated by the IC(50) values of all four keto carotenoids with superior protection by astaxanthin fatty acid monoesters which were as effective as free astaxanthin and of peridinin against radicals. As an example, the in vivo relevance of fucoxanthin for protection of photosynthesis from excess light and from peroxidative agents was evaluated with intact cells. Cultures of P. tricornutum with decreased fucoxanthin content generated by inhibitor treatment were exposed to strong light or cumene hydroperoxyde. In each case, oxidation of chlorophyll as marker for damaging of the photosynthesis apparatus was less severe when the fucoxanthin was at maximum level.

  12. Solar spectral conversion for improving the photosynthetic activity in algae reactors

    NASA Astrophysics Data System (ADS)

    Wondraczek, Lothar; Batentschuk, Miroslaw; Schmidt, Markus A.; Borchardt, Rudolf; Scheiner, Simon; Seemann, Benjamin; Schweizer, Peter; Brabec, Christoph J.

    2013-06-01

    Sustainable biomass production is expected to be one of the major supporting pillars for future energy supply, as well as for renewable material provision. Algal beds represent an exciting resource for biomass/biofuel, fine chemicals and CO2 storage. Similar to other solar energy harvesting techniques, the efficiency of algal photosynthesis depends on the spectral overlap between solar irradiation and chloroplast absorption. Here we demonstrate that spectral conversion can be employed to significantly improve biomass growth and oxygen production rate in closed-cycle algae reactors. For this purpose, we adapt a photoluminescent phosphor of the type Ca0.59Sr0.40Eu0.01S, which enables efficient conversion of the green part of the incoming spectrum into red light to better match the Qy peak of chlorophyll b. Integration of a Ca0.59Sr0.40Eu0.01S backlight converter into a flat panel algae reactor filled with Haematococcus pluvialis as a model species results in significantly increased photosynthetic activity and algae reproduction rate.

  13. Xanthophyllomyces dendrorhous for the industrial production of astaxanthin.

    PubMed

    Rodríguez-Sáiz, Marta; de la Fuente, Juan Luis; Barredo, José Luis

    2010-10-01

    Astaxanthin is a red xanthophyll (oxygenated carotenoid) with large importance in the aquaculture, pharmaceutical, and food industries. The green alga Haematococcus pluvialis and the heterobasidiomycetous yeast Xanthophyllomyces dendrorhous are currently known as the main microorganisms useful for astaxanthin production at the industrial scale. The improvement of astaxanthin titer by microbial fermentation is a requirement to be competitive with the synthetic manufacture by chemical procedures, which at present is the major source in the market. In this review, we show how the isolation of new strains of X. dendrorhous from the environment, the selection of mutants by the classical methods of random mutation and screening, and the rational metabolic engineering, have provided improved strains with higher astaxanthin productivity. To reduce production costs and enhance competitiveness from an industrial point of view, low-cost raw materials from industrial and agricultural origin have been adopted to get the maximal astaxanthin productivity. Finally, fermentation parameters have been studied in depth, both at flask and fermenter scales, to get maximal astaxanthin titers of 4.7 mg/g dry cell matter (420 mg/l) when X. dendrorhous was fermented under continuous white light. The industrial scale-up of this biotechnological process will provide a cost-effective method, alternative to synthetic astaxanthin, for the commercial exploitation of the expensive astaxanthin (about $2,500 per kilogram of pure astaxanthin).

  14. Recent breakthroughs in the biology of astaxanthin accumulation by microalgal cell.

    PubMed

    Solovchenko, Alexei E

    2015-09-01

    Massive accumulation of the secondary ketokarotenoid astaxanthin is a characteristic stress response of certain microalgal species with Haematococcus pluvialis as an illustrious example. The carotenogenic response confers these organisms a remarkable ability to survive in extremely unfavorable environments and makes them the richest source of natural astaxanthin. Exerting a plethora of beneficial effects on human and animal health, astaxanthin is among the most important bioproducts from microalgae. Though our understanding of astaxanthin biosynthesis, induction, and regulation is far from complete, this gap is filling rapidly with new knowledge generated predominantly by application of advanced "omics" approaches. This review focuses on the most recent progress in the biology of astaxanthin accumulation in microalgae including the genomic, proteomic, and metabolomics insights into the induction and regulation of secondary carotenogenesis and its role in stress tolerance of the photosynthetic microorganisms. Special attention is paid to the coupling of the carotenoid and lipid biosynthesis as well as deposition of astaxanthin in the algal cell. The place of the carotenogenic response among the stress tolerance mechanisms is revisited, and possible implications of the new findings for biotechnological production of astaxanthin from microalgae are considered. The potential use of the carotenogenic microalgae as a source not only of value-added carotenoids, but also of biofuel precursors is discussed.

  15. Preventive effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice.

    PubMed

    Komatsu, Toshiyuki; Sasaki, Suguru; Manabe, Yuki; Hirata, Takashi; Sugawara, Tatsuya

    2017-01-01

    Astaxanthin, a carotenoid found mainly in seafood, has potential clinical applications due to its antioxidant activity. In this study, we evaluated the effect of dietary astaxanthin derived from Haematococcus pluvialis on skin photoaging in UVA-irradiated hairless mice by assessing various parameters of photoaging. After chronic ultraviolet A (UVA) exposure, a significant increase in transepidermal water loss (TEWL) and wrinkle formation in the dorsal skin caused by UVA was observed, and dietary astaxanthin significantly suppressed these photoaging features. We found that the mRNA expression of lympho-epithelial Kazal-type-related inhibitor, steroid sulfatase, and aquaporin 3 in the epidermis was significantly increased by UVA irradiation for 70 days, and dietary astaxanthin significantly suppressed these increases in mRNA expression to be comparable to control levels. In the dermis, the mRNA expression of matrix metalloprotease 13 was increased by UVA irradiation and significantly suppressed by dietary astaxanthin. In addition, HPLC-PDA analysis confirmed that dietary astaxanthin reached not only the dermis but also the epidermis. Our results indicate that dietary astaxanthin accumulates in the skin and appears to prevent the effects of UVA irradiation on filaggrin metabolism and desquamation in the epidermis and the extracellular matrix in the dermis.

  16. Genetic engineering of the complete carotenoid pathway towards enhanced astaxanthin formation in Xanthophyllomyces dendrorhous starting from a high-yield mutant.

    PubMed

    Gassel, Sören; Breitenbach, Jürgen; Sandmann, Gerhard

    2014-01-01

    The yeast Xanthophyllomyces dendrorhous is one of the rare organisms which can synthesize the commercially interesting carotenoid astaxanthin. However, astaxanthin yield in wild-type and also in classical mutants is still too low for an attractive bioprocess. Therefore, we combined classical mutagenesis with genetic engineering of the complete pathway covering improved precursor supply for carotenogenesis, enhanced metabolite flow into the pathway, and efficient conversion of intermediates into the desired end product astaxanthin. We also constructed new transformation plasmids for the stepwise expression of the genes of 3-hydroxymethyl-3-glutaryl coenzyme A reductase, geranylgeranyl pyrophosphate synthase, phytoene synthase/lycopene cyclase, and astaxanthin synthase. Starting from two mutants with a 15-fold higher astaxanthin, we obtained transformants with an additional 6-fold increase in the final step of pathway engineering. Thus, a maximum astaxanthin content of almost 9 mg per g dry weight was reached in shaking cultures. Under optimized fermenter conditions, astaxanthin production with these engineered transformants should be comparable to Haematococcus pluvialis, the leading commercial producer of natural astaxanthin.

  17. Construction of transplastomic lettuce (Lactuca sativa) dominantly producing astaxanthin fatty acid esters and detailed chemical analysis of generated carotenoids.

    PubMed

    Harada, Hisashi; Maoka, Takashi; Osawa, Ayako; Hattan, Jun-Ichiro; Kanamoto, Hirosuke; Shindo, Kazutoshi; Otomatsu, Toshihiko; Misawa, Norihiko

    2014-04-01

    The plastid genome of lettuce (Lactuca sativa L.) cv. Berkeley was site-specifically modified with the addition of three transgenes, which encoded β,β-carotenoid 3,3'-hydroxylase (CrtZ) and β,β-carotenoid 4,4'-ketolase (4,4'-oxygenase; CrtW) from a marine bacterium Brevundimonas sp. strain SD212, and isopentenyl diphosphate isomerase from a marine bacterium Paracoccus sp. strain N81106. Constructed transplastomic lettuce plants were able to grow on soil at a growth rate similar to that of non-transformed lettuce cv. Berkeley and generate flowers and seeds. The germination ratio of the lettuce transformants (T0) (98.8%) was higher than that of non-transformed lettuce (93.1 %). The transplastomic lettuce (T1) leaves produced the astaxanthin fatty acid (myristate or palmitate) diester (49.2% of total carotenoids), astaxanthin monoester (18.2%), and the free forms of astaxanthin (10.0%) and the other ketocarotenoids (17.5%), which indicated that artificial ketocarotenoids corresponded to 94.9% of total carotenoids (230 μg/g fresh weight). Native carotenoids were there lactucaxanthin (3.8%) and lutein (1.3 %) only. This is the first report to structurally identify the astaxanthin esters biosynthesized in transgenic or transplastomic plants producing astaxanthin. The singlet oxygen-quenching activity of the total carotenoids extracted from the transplastomic leaves was similar to that of astaxanthin (mostly esterified) from the green algae Haematococcus pluvialis.

  18. Directed Evolution of Dunaliella salina Ds-26-16 and Salt-Tolerant Response in Escherichia coli

    PubMed Central

    Guo, Yuan; Dong, Yanping; Hong, Xiao; Pang, Xiaonan; Chen, Defu; Chen, Xiwen

    2016-01-01

    Identification and evolution of salt tolerant genes are crucial steps in developing salt tolerant crops or microorganisms using biotechnology. Ds-26-16, a salt tolerant gene that was isolated from Dunaliella salina, encodes a transcription factor that can confer salt tolerance to a number of organisms including Escherichia coli (E. coli), Haematococcus pluvialis and tobacco. To further improve its salt tolerance, a random mutagenesis library was constructed using deoxyinosine triphosphate-mediated error-prone PCR technology, and then screened using an E. coli expression system that is based on its broad-spectrum salt tolerance. Seven variants with enhanced salt tolerance were obtained. Variant EP-5 that contained mutation S32P showed the most improvement with the E. coli transformant enduring salt concentrations up to 1.54 M, in comparison with 1.03 M for the wild type gene. Besides, Ds-26-16 and EP-5 also conferred E. coli transformant tolerance to freezing, cold, heat, Cu2+ and alkaline. Homology modeling revealed that mutation S32P in EP-5 caused the conformational change of N- and C-terminal α-helixes. Expression of Ds-26-16 and EP-5 maintained normal cellular morphology, increased the intracellular antioxidant enzymatic activity, reduced malondialdehyde content, and stimulated Nitric Oxide synthesis, thus enhancing salt tolerance to E. coli transformants. PMID:27801872

  19. Preventive effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice

    PubMed Central

    Komatsu, Toshiyuki; Sasaki, Suguru; Manabe, Yuki; Hirata, Takashi

    2017-01-01

    Astaxanthin, a carotenoid found mainly in seafood, has potential clinical applications due to its antioxidant activity. In this study, we evaluated the effect of dietary astaxanthin derived from Haematococcus pluvialis on skin photoaging in UVA-irradiated hairless mice by assessing various parameters of photoaging. After chronic ultraviolet A (UVA) exposure, a significant increase in transepidermal water loss (TEWL) and wrinkle formation in the dorsal skin caused by UVA was observed, and dietary astaxanthin significantly suppressed these photoaging features. We found that the mRNA expression of lympho-epithelial Kazal-type-related inhibitor, steroid sulfatase, and aquaporin 3 in the epidermis was significantly increased by UVA irradiation for 70 days, and dietary astaxanthin significantly suppressed these increases in mRNA expression to be comparable to control levels. In the dermis, the mRNA expression of matrix metalloprotease 13 was increased by UVA irradiation and significantly suppressed by dietary astaxanthin. In addition, HPLC-PDA analysis confirmed that dietary astaxanthin reached not only the dermis but also the epidermis. Our results indicate that dietary astaxanthin accumulates in the skin and appears to prevent the effects of UVA irradiation on filaggrin metabolism and desquamation in the epidermis and the extracellular matrix in the dermis. PMID:28170435

  20. Colonization of Snow by Microorganisms as Revealed Using Miniature Raman Spectrometers-Possibilities for Detecting Carotenoids of Psychrophiles on Mars?

    PubMed

    Jehlička, Jan; Culka, Adam; Nedbalová, Linda

    2016-12-01

    We tested the potential of a miniaturized Raman spectrometer for use in field detection of snow algae pigments. A miniature Raman spectrometer, equipped with an excitation laser at 532 nm, allowed for the detection of carotenoids in cells of Chloromonas nivalis and Chlamydomonas nivalis at different stages of their life cycle. Astaxanthin, the major photoprotective pigment, was detected in algal blooms originating in snows at two alpine European sites that differed in altitude (Krkonoše Mts., Czech Republic, 1502 m a.s.l., and Ötztal Alps, Austria, 2790 m a.s.l.). Comparison is made with a common microalga exclusively producing astaxanthin (Haematococcus pluvialis). The handheld Raman spectrometer is a useful tool for fast and direct field estimations of the presence of carotenoids (mainly astaxanthin) within blooms of snow algae. Application of miniature Raman instruments as well as flight prototypes in areas where microbes are surviving under extreme conditions is an important stage in preparation for successful deployment of this kind of instrumentation in the framework of forthcoming astrobiological missions to Mars. Key Words: Snow algae-Chloromonas nivalis-Chlamydomonas nivalis-On-site field detection-Raman spectroscopy-Astaxanthin. Astrobiology 16, 913-924.

  1. In Vitro Effects of Some Botanicals with Anti-Inflammatory and Antitoxic Activity.

    PubMed

    Guidetti, Gianandrea; Di Cerbo, Alessandro; Giovazzino, Angela; Rubino, Valentina; Palatucci, Anna Teresa; Centenaro, Sara; Fraccaroli, Elena; Cortese, Laura; Bonomo, Maria Grazia; Ruggiero, Giuseppina; Canello, Sergio; Terrazzano, Giuseppe

    2016-01-01

    Several extrinsic factors, like drugs and chemicals, can foster autoimmunity. Tetracyclines, in particular oxytetracycline (OTC), appear to correlate with the emergence of immune-mediated diseases. Accumulation of OTC, the elective drug for gastrointestinal and respiratory infectious disease treatment in broiler chickens, was reported in chicken edible tissues and could represent a potential risk for pets and humans that could assume this antibiotic as residue in meat or in meat-derived byproducts. We investigated the in vitro anti-inflammatory properties of a pool of thirteen botanicals as a part of a nutraceutical diet, with proven immunomodulatory activity. In addition, we evaluated the effect of such botanicals in contrasting the in vitro proinflammatory toxicity of OTC. Our results showed a significant reduction in interferon- (INF-) γ production by human and canine lymphocytes in presence of botanicals ((⁎) p < 0.05). Increased INF-γ production, dependent on 24-hour OTC-incubation of T lymphocytes, was significantly reduced by the coincubation with Haematococcus pluvialis, with Glycine max, and with the mix of all botanicals ((⁎) p < 0.05). In conclusion, the use of these botanicals was shown to be able to contrast OTC-toxicity and could represent a new approach for the development of functional foods useful to enhance the standard pharmacological treatment in infections as well as in preventing or reducing the emergence of inflammatory diseases.

  2. [Microbial sources of pigments].

    PubMed

    Cañizares-Villanueva, R O; Ríos-Leal, E; Olvera Ramírez, R; Ponce Noyola, T; Márquez Rocha, F

    1998-01-01

    Pigments from natural sources has been obtained since long time ago, and their interest has increased due to the toxicity problems caused by those of synthetic origin. In this way the pigments from microbial sources are a good alternative. Some of more important natural pigments, are the carotenoids, flavonoids (anthocyanins) and some tetrapirroles (chloropyls, phycobilliproteins). Another group less important are the betalains and quinones. The carotenoids are molecules formed by isoprenoids units and the most important used as colorant are the alpha and beta carotene which are precursors of vitamin A, and some xantophylls as astaxanthin. The pigment more used in the industry is the beta-carotene which is obtained from some microalgae and cyanobacteria. The astaxanthin another important carotenoid is a red pigment of great commercial value, and it is used in the pharmaceutical feed and acuaculture industries. This pigments is mainly obtained from Phaffia rhodozyma and Haematococcus pluvialis and other organisms. The phycobilliproteins obtained from cyanobacteria and some group of algae, have recently been increased on the food industries. In the last years it has been used as fluorescent marker in biochemical assays. Our research group have carried out studies about the factors that improve the production of these pigments obtained from different microbial species as well as the methods for their extraction and application.

  3. Directed Evolution of Dunaliella salina Ds-26-16 and Salt-Tolerant Response in Escherichia coli.

    PubMed

    Guo, Yuan; Dong, Yanping; Hong, Xiao; Pang, Xiaonan; Chen, Defu; Chen, Xiwen

    2016-10-29

    Identification and evolution of salt tolerant genes are crucial steps in developing salt tolerant crops or microorganisms using biotechnology. Ds-26-16, a salt tolerant gene that was isolated from Dunaliella salina, encodes a transcription factor that can confer salt tolerance to a number of organisms including Escherichia coli (E. coli), Haematococcus pluvialis and tobacco. To further improve its salt tolerance, a random mutagenesis library was constructed using deoxyinosine triphosphate-mediated error-prone PCR technology, and then screened using an E. coli expression system that is based on its broad-spectrum salt tolerance. Seven variants with enhanced salt tolerance were obtained. Variant EP-5 that contained mutation S32P showed the most improvement with the E. coli transformant enduring salt concentrations up to 1.54 M, in comparison with 1.03 M for the wild type gene. Besides, Ds-26-16 and EP-5 also conferred E. coli transformant tolerance to freezing, cold, heat, Cu(2+) and alkaline. Homology modeling revealed that mutation S32P in EP-5 caused the conformational change of N- and C-terminal α-helixes. Expression of Ds-26-16 and EP-5 maintained normal cellular morphology, increased the intracellular antioxidant enzymatic activity, reduced malondialdehyde content, and stimulated Nitric Oxide synthesis, thus enhancing salt tolerance to E. coli transformants.

  4. Production of stable food-grade microencapsulated astaxanthin by vibrating nozzle technology.

    PubMed

    Vakarelova, Martina; Zanoni, Francesca; Lardo, Piergiovanni; Rossin, Giacomo; Mainente, Federica; Chignola, Roberto; Menin, Alessia; Rizzi, Corrado; Zoccatelli, Gianni

    2017-04-15

    Astaxanthin is a carotenoid known for its strong antioxidant and health-promoting characteristics, but it is also highly degradable and thus unsuited for several applications. We developed a sustainable method for the extraction and the production of stable astaxanthin microencapsulates. Nearly 2% astaxanthin was extracted by high-pressure homogenization of dried Haematococcus pluvialis cells in soybean oil. Astaxanthin-enriched oil was encapsulated in alginate and low-methoxyl pectin by Ca(2+)-mediated vibrating-nozzle extrusion technology. The 3% pectin microbeads resulted the best compromise between sphericity and oil retention upon drying. We monitored the stability of these astaxanthin beads under four different conditions of light, temperature and oxygen exposition. After 52weeks, the microbeads showed a total-astaxanthin retention of 94.1±4.1% (+4°C/-light/+O2), 83.1±3.2% (RT/-light/-O2), 38.3±2.2% (RT/-light/+O2), and 57.0±0.4% (RT/+light/+O2), with different degradation kinetics. Refrigeration, therefore, resulted the optimal storage condition to preserve astaxanthin stability.

  5. Catalytic improvement and structural analysis of atrazine chlorohydrolase by site-saturation mutagenesis.

    PubMed

    Guo, Yuan; Zhao, Panjie; Zhang, Wenhao; Li, Xiaolong; Chen, Xiwen; Chen, Defu

    2016-07-01

    To improve the catalytic activity of atrazine chlorohydrolase (AtzA), amino acid residues involved in substrate binding (Gln71) and catalytic efficiency (Val12, Ile393, and Leu395) were targeted to generate site-saturation mutagenesis libraries. Seventeen variants were obtained through Haematococcus pluvialis-based screening, and their specific activities were 1.2-5.2-fold higher than that of the wild type. For these variants, Gln71 tended to be substituted by hydrophobic amino acids, Ile393 and Leu395 by polar ones, especially arginine, and Val12 by alanine, respectively. Q71R and Q71M significantly decreased the Km by enlarging the substrate-entry channel and affecting N-ethyl binding. Mutations at sites 393 and 395 significantly increased the kcat/Km, probably by improving the stability of the dual β-sheet domain and the whole enzyme, owing to hydrogen bond formation. In addition, the contradictory relationship between the substrate affinity improvement by Gln71 mutation and the catalytic efficiency improvement by the dual β-sheet domain modification was discussed.

  6. Colonization of Snow by Microorganisms as Revealed Using Miniature Raman Spectrometers - Possibilities for Detecting Carotenoids of Psychrophiles on Mars?

    NASA Astrophysics Data System (ADS)

    Jehlička, Jan; Culka, Adam; Nedbalová, Linda

    2016-12-01

    We tested the potential of a miniaturized Raman spectrometer for use in field detection of snow algae pigments. A miniature Raman spectrometer, equipped with an excitation laser at 532 nm, allowed for the detection of carotenoids in cells of Chloromonas nivalis and Chlamydomonas nivalis at different stages of their life cycle. Astaxanthin, the major photoprotective pigment, was detected in algal blooms originating in snows at two alpine European sites that differed in altitude (Krkonoše Mts., Czech Republic, 1502 m a.s.l., and Ötztal Alps, Austria, 2790 m a.s.l.). Comparison is made with a common microalga exclusively producing astaxanthin (Haematococcus pluvialis). The handheld Raman spectrometer is a useful tool for fast and direct field estimations of the presence of carotenoids (mainly astaxanthin) within blooms of snow algae. Application of miniature Raman instruments as well as flight prototypes in areas where microbes are surviving under extreme conditions is an important stage in preparation for successful deployment of this kind of instrumentation in the framework of forthcoming astrobiological missions to Mars.

  7. Solar spectral conversion for improving the photosynthetic activity in algae reactors.

    PubMed

    Wondraczek, Lothar; Batentschuk, Miroslaw; Schmidt, Markus A; Borchardt, Rudolf; Scheiner, Simon; Seemann, Benjamin; Schweizer, Peter; Brabec, Christoph J

    2013-01-01

    Sustainable biomass production is expected to be one of the major supporting pillars for future energy supply, as well as for renewable material provision. Algal beds represent an exciting resource for biomass/biofuel, fine chemicals and CO2 storage. Similar to other solar energy harvesting techniques, the efficiency of algal photosynthesis depends on the spectral overlap between solar irradiation and chloroplast absorption. Here we demonstrate that spectral conversion can be employed to significantly improve biomass growth and oxygen production rate in closed-cycle algae reactors. For this purpose, we adapt a photoluminescent phosphor of the type Ca0.59Sr0.40Eu0.01S, which enables efficient conversion of the green part of the incoming spectrum into red light to better match the Qy peak of chlorophyll b. Integration of a Ca0.59Sr0.40Eu0.01S backlight converter into a flat panel algae reactor filled with Haematococcus pluvialis as a model species results in significantly increased photosynthetic activity and algae reproduction rate.

  8. Evolutionary origins, molecular cloning and expression of carotenoid hydroxylases in eukaryotic photosynthetic algae

    PubMed Central

    2013-01-01

    Background Xanthophylls, oxygenated derivatives of carotenes, play critical roles in photosynthetic apparatus of cyanobacteria, algae, and higher plants. Although the xanthophylls biosynthetic pathway of algae is largely unknown, it is of particular interest because they have a very complicated evolutionary history. Carotenoid hydroxylase (CHY) is an important protein that plays essential roles in xanthophylls biosynthesis. With the availability of 18 sequenced algal genomes, we performed a comprehensive comparative analysis of chy genes and explored their distribution, structure, evolution, origins, and expression. Results Overall 60 putative chy genes were identified and classified into two major subfamilies (bch and cyp97) according to their domain structures. Genes in the bch subfamily were found in 10 green algae and 1 red alga, but absent in other algae. In the phylogenetic tree, bch genes of green algae and higher plants share a common ancestor and are of non-cyanobacterial origin, whereas that of red algae is of cyanobacteria. The homologs of cyp97a/c genes were widespread only in green algae, while cyp97b paralogs were seen in most of algae. Phylogenetic analysis on cyp97 genes supported the hypothesis that cyp97b is an ancient gene originated before the formation of extant algal groups. The cyp97a gene is more closely related to cyp97c in evolution than to cyp97b. The two cyp97 genes were isolated from the green alga Haematococcus pluvialis, and transcriptional expression profiles of chy genes were observed under high light stress of different wavelength. Conclusions Green algae received a β-xanthophylls biosynthetic pathway from host organisms. Although red algae inherited the pathway from cyanobacteria during primary endosymbiosis, it remains unclear in Chromalveolates. The α-xanthophylls biosynthetic pathway is a common feature in green algae and higher plants. The origination of cyp97a/c is most likely due to gene duplication before divergence of

  9. Determination of astaxanthin stereoisomers and colour attributes in flesh of rainbow trout (Oncorhynchus mykiss) as a tool to distinguish the dietary pigmentation source.

    PubMed

    Moretti, V M; Mentasti, T; Bellagamba, F; Luzzana, U; Caprino, F; Turchini, G M; Giani, I; Valfrè, F

    2006-11-01

    The presence of carotenoids in animal tissue reflects their sources along the food chain. Astaxanthin, the main carotenoid used for salmonid pigmentation, is usually included in the feed as a synthetic product. However, other dietary sources of astaxanthin such as shrimp or krill wastes, algae meal or yeasts are also available on the market. Astaxanthin possesses two identical asymmetric atoms at C-3 and C-3' making possible three optical isomers with all-trans configuration of the chain: 3S,3'S, 3R,3'S, and 3R,3'R. The distribution of the isomers in natural astaxanthin differs from that of the synthetic product. This latter is a racemic mixture, with a typical ratio of 1:2:1 (3S,3'S:3R,3'S:3R,3'R), while astaxanthin from natural sources has a variable distribution of the isomers deriving from the different biological organism that synthesized it. The high-performance liquid chromatographic (HPLC) analysis of all-trans isomers of astaxanthin was performed in different pigment sources, such as red yeast Phaffia rhodozyma, alga meal Haematococcus pluvialis, krill meal and oil, and shrimp meal. With the aim to investigate astaxanthin isomer ratios in flesh of fish fed different carotenoid sources, three groups of rainbow trout were fed for 60 days diets containing astaxanthin from synthetic source, H. pluvialis algae meal and P. rhodozyma red yeast. Moreover, the distribution of optical isomers of astaxanthin in trout purchased on the Italian market was investigated. A characteristic distribution of astaxanthin stereoisomers was detected for each pigment sources and such distribution was reproduced in the flesh of trout fed with that source. Colour values measured in different sites of fillet of rainbow trout fed with different pigment sources showed no significant differences. Similarly, different sources of pigment (natural or synthetic) produced colour values of fresh fillet with no relevant or significant differences. The coefficient of distance computed amongst

  10. Taxonomic revision of Chlamydomonas subg. Amphichloris (Volvocales, Chlorophyceae), with resurrection of the genus Dangeardinia and descriptions of Ixipapillifera gen. nov. and Rhysamphichloris gen. nov.

    PubMed

    Nakada, Takashi; Tomita, Masaru; Wu, Jiunn-Tzong; Nozaki, Hisayoshi

    2016-04-01

    Chlamydomonas (Cd.) is one of the largest but most polyphyletic genera of freshwater unicellular green algae. It consists of 400-600 morphological species and requires taxonomic revision. Toward reclassification, each morphologically defined classical subgenus (or subgroup) should be examined using culture strains. Chlamydomonas subg. Amphichloris is characterized by a central nucleus between two axial pyrenoids, however, the phylogenetic structure of this subgenus has yet to be examined using molecular data. Here, we examined 12 strains including six newly isolated strains, morphologically identified as Chlamydomonas subg. Amphichloris, using 18S rRNA gene phylogeny, light microscopy, and mitochondria fluorescent microscopy. Molecular phylogenetic analyses revealed three independent lineages of the subgenus, separated from the type species of Chlamydomonas, Cd. reinhardtii. These three lineages were further distinguished from each other by light and fluorescent microscopy-in particular by the morphology of the papillae, chloroplast surface, stigmata, and mitochondria-and are here assigned to three genera: Dangeardinia emend., Ixipapillifera gen. nov., and Rhysamphichloris gen. nov. Based on the molecular and morphological data, two to three species were recognized in each genus, including one new species, I. pauromitos. In addition, Cd. deasonii, which was previously assigned to subgroup "Pleiochloris," was included in the genus Ixipapillifera as I. deasonii comb. nov. © 2016 Phycological Society of America.

  11. Seasonal and diel changes in photosynthetic activity of the snow alga Chlamydomonas nivalis (Chlorophyceae) from Svalbard determined by pulse amplitude modulation fluorometry.

    PubMed

    Stibal, Marek; Elster, Josef; Sabacká, Marie; Kastovská, Klára

    2007-02-01

    The seasonal and diel dynamics of the physiological state and photosynthetic activity of the snow alga Chlamydomonas nivalis were investigated in a snowfield in Svalbard. The snow surface represents an environment with very high irradiation intensities along with stable low temperatures close to freezing point. Photosynthetic activity was measured using pulse amplitude modulation fluorometry. Three types of cell (green biflagellate vegetative cells, orange spores clustered by means of mucilaginous sheaths, and purple spores with thick cell walls) were found, all of them photosynthetically active. The pH of snow ranged between 5.0 and 7.5, and the conductivity ranged between 5 and 75 microS cm(-1). The temperature of snow was stable (-0.1 to +0.1 degrees C), and the incident radiation values ranged from 11 to 1500 micromol photons m(-2) s(-1). The photosynthetic activity had seasonal and diel dynamics. The Fv/Fm values ranged between 0.4 and 0.7, and generally declined over the course of the season. A dynamic response of Fv/Fm to the irradiance was recorded. According to the saturating photon fluence values Ek, the algae may have obtained saturating light as deep as 3 cm in the snow when there were higher-light conditions, whereas they were undersaturated at prevalent low light even if on the surface.

  12. Differential responses to Cr(VI)-induced oxidative stress between Cr-tolerant and wild-type strains of Scenedesmus acutus (Chlorophyceae).

    PubMed

    Gorbi, Gessica; Torricelli, Elena; Pawlik-Skowrońska, Barbara; di Toppi, Luigi Sanità; Zanni, Corrado; Corradi, Maria Grazia

    2006-08-23

    A wild-type and a Cr-tolerant strain of the unicellular green alga Scenedesmus acutus were used to investigate if the difference in tolerance to Cr(VI) could depend on a different response to oxidative stress in terms of free cysteine (Cys) and reduced glutathione (GSH), and in preventing membrane lipid peroxidation. The growth of the two strains in standard medium in the presence of Cr(VI) 9.6, 19.2 or 38.4microM was compared, and the content of thiobarbituric acid reactive substances (TBARS) after a 4-day treatment was determined as marker of lipid peroxidation. The Cys and GSH contents were determined in both strains treated with Cr(VI) for 24h in HEPES buffer both enriched and not with sulphate. The treated algae were also subjected to recovery test in standard medium. The growth of wild type was inhibited at all Cr(VI) concentrations, while that of the Cr-tolerant strain only at the highest one. After exposure to 19.2microM Cr(VI), TBARS levels ranging from 0.091 to 0.263micromol/g d.w. were detected in the wild type, while only a slight increase (0.090+/-0.014micromol/g d.w.) was observed in the Cr-tolerant strain. Following treatment with 38.4microM Cr(VI), TBARS levels rose significantly and were similar in the two strains. The Cys content did not vary significantly in the cells exposed to Cr(VI) in either sulphate-lacking or sulphate-enriched buffer, and the differences between the two strains were insignificant. In the wild-type strain, the GSH content showed a significant downward trend with the increase in Cr(VI) concentration in the sulphate-lacking buffer, while it remained as high as the one of control cells in the sulphate-enriched buffer. In the Cr-tolerant strain, the GSH content did not vary significantly when the treatment took place in the sulphate-lacking buffer, while it showed a significant rise with the increase in Cr(VI) concentration in the sulphate-enriched buffer. The growth of both strains during recovery was significantly faster after treatment in the sulphate-enriched than in the sulphate-lacking buffer, the Cr-tolerant strain showing a much higher recovery capacity than the wild type. It appears that the Cr-tolerant strain, when exposed to Cr(VI) in the presence of a sulphur source, can increase GSH pool to levels not achievable by the wild type, and is thus able to recover better. This first report on the role of thiol compounds in Cr tolerance in algae suggests that tolerance to Cr(VI) in S. acutus could depend on a prompt up-regulation of the pathways leading to GSH synthesis.

  13. Evidence for a facultative mutualist nutritional relationship between the green coccoid alga Bracteacoccus sp. (Chlorophyceae) and the zoosporic fungus Rhizidium phycophilum (Chytridiomycota).

    PubMed

    Picard, Kathryn T; Letcher, Peter M; Powell, Martha J

    2013-05-01

    Symbiotic interactions between fungi and photosynthetic partners are common among derived fungal lineages. The only fungal-phototroph interactions thus far reported from the early diverging zoosporic fungi are parasitic in nature. Rhizidium phycophilum is a terrestrial, saprotrophic chytrid, which appears to be able to enter a facultative mutualism with a coccoid green alga in the absence of refractory organic material, such as pollen and chitin. Liquid and solid culturing methods were used in a series of differential fitness experiments in conjunction with microscopic analyses to characterize the interaction between R. phycophilum and the alga. The alga in this partnership is identified as a member of the genus Bracteacoccus. Under certain culturing conditions, algal cells grown in coculture with R. phycophilum were shown to grow larger and more prolifically than when cultured axenically under the same conditions. Additionally, dialysis experiments demonstrate that R. phycophilum does not parasitize Bracteacoccus sp., and can be cultured in media infused with unknown algal exudates. Rhizidium phycophilum and Bracteacoccus sp. represent the first facultative positive interaction between a zoosporic fungus and a photoautotroph and may prove a tractable system for modelling interactions between early fungi and plants. Copyright © 2013 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  14. Molecular taxonomy of Dunaliella (Chlorophyceae), with a special focus on D. salina: ITS2 sequences revisited with an extensive geographical sampling

    PubMed Central

    2012-01-01

    We used an ITS2 primary and secondary structure and Compensatory Base Changes (CBCs) analyses on new French and Spanish Dunallela salina strains to investigate their phylogenetic position and taxonomic status within the genus Dunaliella. Our analyses show a great diversity within D. salina (with only some clades not statistically supported) and reveal considerable genetic diversity and structure within Dunaliella, although the CBC analysis did not bolster the existence of different biological groups within this taxon. The ITS2 sequences of the new Spanish and French D. salina strains were very similar except for two of them: ITC5105 "Janubio" from Spain and ITC5119 from France. Although the Spanish one had a unique ITS2 sequence profile and the phylogenetic tree indicates that this strain can represent a new species, this hypothesis was not confirmed by CBCs, and clarification of its taxonomic status requires further investigation with new data. Overall, the use of CBCs to define species boundaries within Dunaliella was not conclusive in some cases, and the ITS2 region does not contain a geographical signal overall. PMID:22520929

  15. Ketocarotenoid Production in Soybean Seeds through Metabolic Engineering.

    PubMed

    Pierce, Emily C; LaFayette, Peter R; Ortega, María A; Joyce, Blake L; Kopsell, Dean A; Parrott, Wayne A

    2015-01-01

    The pink or red ketocarotenoids, canthaxanthin and astaxanthin, are used as feed additives in the poultry and aquaculture industries as a source of egg yolk and flesh pigmentation, as farmed animals do not have access to the carotenoid sources of their wild counterparts. Because soybean is already an important component in animal feed, production of these carotenoids in soybean could be a cost-effective means of delivery. In order to characterize the ability of soybean seed to produce carotenoids, soybean cv. Jack was transformed with the crtB gene from Pantoea ananatis, which codes for phytoene synthase, an enzyme which catalyzes the first committed step in the carotenoid pathway. The crtB gene was engineered together in combinations with ketolase genes (crtW from Brevundimonas sp. strain SD212 and bkt1 from Haematococcus pluvialis) to produce ketocarotenoids; all genes were placed under the control of seed-specific promoters. HPLC results showed that canthaxanthin is present in the transgenic seeds at levels up to 52 μg/g dry weight. Transgenic seeds also accumulated other compounds in the carotenoid pathway, such as astaxanthin, lutein, β-carotene, phytoene, α-carotene, lycopene, and β-cryptoxanthin, whereas lutein was the only one of these detected in non-transgenic seeds. The accumulation of astaxanthin, which requires a β-carotene hydroxylase in addition to a β-carotene ketolase, in the transgenic seeds suggests that an endogenous soybean enzyme is able to work in combination with the ketolase transgene. Soybean seeds that accumulate ketocarotenoids could potentially be used in animal feed to reduce or eliminate the need for the costly addition of these compounds.

  16. Mussel processing wastewater: a low-cost substrate for the production of astaxanthin by Xanthophyllomyces dendrorhous.

    PubMed

    Amado, Isabel Rodríguez; Vázquez, José Antonio

    2015-11-09

    The use of astaxanthin in different industries such as the chemical, pharmaceutical, food, animal feed and cosmetic has been receiving increasing attention in recent years. Natural supplies of the pigment include crustacean by-products, algal, and microbial cultivation, being the yeast Xanthophyllomyces dendrorhous together with the alga Haematococcus pluvialis the most promising microorganisms for this bioproduction. Different vegetable by-products of the food industry have been explored so far as low-cost substrates for the production of astaxanthin by X. dendrorhous. This study focuses for the first time on the use of a low-cost formulated medium from a marine by-product, mussel-processing wastewater, for the production of astaxanthin by the yeast X. dendrorhous. The yeast was able to grow in non-saccharified mussel broth, revealing the ability of the microorganism to hydrolyze glycogen. However, partial glycogen saccharification with α-amylase was needed for astaxanthin biosynthesis, obtaining maximal productions of 22.5-26.0 mg/L towards the end of the culture and coinciding with yeast highest amylolytic activity. Cultivations in totally-saccharified media revealed an increase in maximal cell concentrations and a decrease in maximal growth rates and astaxanthin production with increasing glucose initial concentration. Astaxanthin production was higher in partially-saccharified mussel-processing waste than in synthetic medium (yeast peptone dextrose) containing glucose as carbon source (13 mg/L), suggesting this by-product is a promising nutritive medium for astaxanthin production. The use of this effluent also contributes towards the recycling and depuration of this highly pollutant effluent.

  17. Functional characterization of various algal carotenoid ketolases reveals that ketolating zeaxanthin efficiently is essential for high production of astaxanthin in transgenic Arabidopsis

    PubMed Central

    Zhong, Yu-Juan; Huang, Jun-Chao; Liu, Jin; Li, Yin; Jiang, Yue; Xu, Zeng-Fu; Sandmann, Gerhard; Chen, Feng

    2011-01-01

    Extending the carotenoid pathway to astaxanthin in plants is of scientific and industrial interest. However, expression of a microbial β-carotene ketolase (BKT) that catalyses the formation of ketocarotenoids in transgenic plants typically results in low levels of astaxanthin. The low efficiency of BKTs in ketolating zeaxanthin to astaxanthin is proposed to be the major limitation for astaxanthin accumulation in engineered plants. To verify this hypothesis, several algal BKTs were functionally characterized using an Escherichia coli system and three BKTs were identified, with high (up to 85%), moderate (∼38%), and low (∼1%) conversion rate from zeaxanthin to astaxanthin from Chlamydomonas reinhardtii (CrBKT), Chlorella zofingiensis (CzBKT), and Haematococcus pluvialis (HpBKT3), respectively. Transgenic Arabidopsis thaliana expressing the CrBKT developed orange leaves which accumulated astaxanthin up to 2 mg g−1 dry weight with a 1.8-fold increase in total carotenoids. In contrast, the expression of CzBKT resulted in much lower astaxanthin content (0.24 mg g−1 dry weight), whereas HpBKT3 was unable to mediate synthesis of astaxanthin in A. thaliana. The none-native astaxanthin was found mostly in a free form integrated into the light-harvesting complexes of photosystem II in young leaves but in esterified forms in senescent leaves. The alteration of carotenoids did not affect chlorophyll content, plant growth, or development significantly. The astaxanthin-producing plants were more tolerant to high light as shown by reduced lipid peroxidation. This study advances a decisive step towards the utilization of plants for the production of high-value astaxanthin. PMID:21398427

  18. Metabolic engineering of novel ketocarotenoid production in carrot plants.

    PubMed

    Jayaraj, Jayaraman; Devlin, Robert; Punja, Zamir

    2008-08-01

    Carotenoids constitute a vast group of pigments that are ubiquitous throughout nature. Carrot (Daucus carota L.) roots provide an important source of dietary beta-carotene (provitamin A), alpha-carotene and lutein. Ketocarotenoids, such as canthaxanthin and astaxanthin, are produced by some algae and cyanobacteria but are rare in plants. Ketocarotenoids are strong antioxidants that are chemically synthesized and used as dietary supplements and pigments in the aquaculture and neutraceutical industries. We engineered the ketocarotenoid biosynthetic pathway in carrot tissues by introducing a beta-carotene ketolase gene isolated from the alga Haematococcus pluvialis. Gene constructs were made with three promoters (double CaMV 35S, Arabidopsis-ubiquitin, and RolD from Agrobacterium rhizogenes). The pea Rubisco small sub-unit transit peptide was used to target the enzyme to plastids in leaf and root tissues. The phosphinothricin acetyl transferase (bar) gene was used as a selectable marker. Following Agrobacterium-mediated transformation, 150 plants were regenerated and grown in a glasshouse. All three promoters provided strong root expression, while the double CaMV 35S and Ubiquitin promoters also had strong leaf expression. The recombinant ketolase protein was successfully targeted to the chloroplasts and chromoplasts. Endogenous expression of carrot beta-carotene hydroxylases was up-regulated in transgenic leaves and roots, and up to 70% of total carotenoids was converted to novel ketocarotenoids, with accumulation up to 2,400 microg/g root dry weight. Astaxanthin, adonirubin, and canthaxanthin were most prevalent, followed by echinenone, adonixanthin and beta-cryptoxanthin. Our results show that carrots are suitable for biopharming ketocarotenoid production for applications to the functional food, neutraceutical and aquaculture industries.

  19. Ketocarotenoid Production in Soybean Seeds through Metabolic Engineering

    PubMed Central

    Pierce, Emily C.; LaFayette, Peter R.; Ortega, María A.; Joyce, Blake L.; Kopsell, Dean A.; Parrott, Wayne A.

    2015-01-01

    The pink or red ketocarotenoids, canthaxanthin and astaxanthin, are used as feed additives in the poultry and aquaculture industries as a source of egg yolk and flesh pigmentation, as farmed animals do not have access to the carotenoid sources of their wild counterparts. Because soybean is already an important component in animal feed, production of these carotenoids in soybean could be a cost-effective means of delivery. In order to characterize the ability of soybean seed to produce carotenoids, soybean cv. Jack was transformed with the crtB gene from Pantoea ananatis, which codes for phytoene synthase, an enzyme which catalyzes the first committed step in the carotenoid pathway. The crtB gene was engineered together in combinations with ketolase genes (crtW from Brevundimonas sp. strain SD212 and bkt1 from Haematococcus pluvialis) to produce ketocarotenoids; all genes were placed under the control of seed-specific promoters. HPLC results showed that canthaxanthin is present in the transgenic seeds at levels up to 52 μg/g dry weight. Transgenic seeds also accumulated other compounds in the carotenoid pathway, such as astaxanthin, lutein, β-carotene, phytoene, α-carotene, lycopene, and β-cryptoxanthin, whereas lutein was the only one of these detected in non-transgenic seeds. The accumulation of astaxanthin, which requires a β-carotene hydroxylase in addition to a β-carotene ketolase, in the transgenic seeds suggests that an endogenous soybean enzyme is able to work in combination with the ketolase transgene. Soybean seeds that accumulate ketocarotenoids could potentially be used in animal feed to reduce or eliminate the need for the costly addition of these compounds. PMID:26376481

  20. Astaxanthin-rich algal meal and vitamin C inhibit Helicobacter pylori infection in BALB/cA mice.

    PubMed

    Wang, X; Willén, R; Wadström, T

    2000-09-01

    Helicobacter pylori infection in humans is associated with chronic type B gastritis, peptic ulcer disease, and gastric carcinoma. A high intake of carotenoids and vitamin C has been proposed to prevent development of gastric malignancies. The aim of this study was to explore if the microalga Haematococcus pluvialis rich in the carotenoid astaxanthin and vitamin C can inhibit experimental H. pylori infection in a BALB/cA mouse model. Six-week-old BALB/cA mice were infected with the mouse-passaged H. pylori strain 119/95. At 2 weeks postinoculation mice were treated orally once daily for 10 days (i) with different doses of algal meal rich in astaxanthin (0.4, 2, and 4 g/kg of body weight, with the astaxanthin content at 10, 50, and 100 mg/kg, respectively), (ii) with a control meal (algal meal without astaxanthin, 4 g/kg), or (iii) with vitamin C (400 mg/kg). Five mice from each group were sacrificed 1 day after the cessation of treatment, and the other five animals were sacrificed 10 days after the cessation of treatment. Culture of H. pylori and determination of the inflammation score of the gastric mucosae were used to determine the outcome of the treatment. Mice treated with astaxanthin-rich algal meal or vitamin C showed significantly lower colonization levels and lower inflammation scores than those of untreated or control-meal-treated animals at 1 day and 10 days after the cessation of treatment. Lipid peroxidation was significantly decreased in mice treated with the astaxanthin-rich algal meal and vitamin C compared with that of animals not treated or treated with the control meal. Both astaxanthin-rich algal meal and vitamin C showed an inhibitory effect on H. pylori growth in vitro. In conclusion, antioxidants may be a new strategy for treating H. pylori infection in humans.

  1. Proteomic Analyses Reveal the Mechanism of Dunaliella salina Ds-26-16 Gene Enhancing Salt Tolerance in Escherichia coli.

    PubMed

    Wang, Yanlong; Hu, Bin; Du, Shipeng; Gao, Shan; Chen, Xiwen; Chen, Defu

    2016-01-01

    We previously screened the novel gene Ds-26-16 from a 4 M salt-stressed Dunaliella salina cDNA library and discovered that this gene conferred salt tolerance to broad-spectrum organisms, including E. coli (Escherichia coli), Haematococcus pluvialis and tobacco. To determine the mechanism of this gene conferring salt tolerance, we studied the proteome of E. coli overexpressing the full-length cDNA of Ds-26-16 using the iTRAQ (isobaric tags for relative and absolute quantification) approach. A total of 1,610 proteins were identified, which comprised 39.4% of the whole proteome. Of the 559 differential proteins, 259 were up-regulated and 300 were down-regulated. GO (gene ontology) and KEGG (Kyoto encyclopedia of genes and genomes) enrichment analyses identified 202 major proteins, including those involved in amino acid and organic acid metabolism, energy metabolism, carbon metabolism, ROS (reactive oxygen species) scavenging, membrane proteins and ABC (ATP binding cassette) transporters, and peptidoglycan synthesis, as well as 5 up-regulated transcription factors. Our iTRAQ data suggest that Ds-26-16 up-regulates the transcription factors in E. coli to enhance salt resistance through osmotic balance, energy metabolism, and oxidative stress protection. Changes in the proteome were also observed in E. coli overexpressing the ORF (open reading frame) of Ds-26-16. Furthermore, pH, nitric oxide and glycerol content analyses indicated that Ds-26-16 overexpression increases nitric oxide content but has no effect on glycerol content, thus confirming that enhanced nitric oxide synthesis via lower intercellular pH was one of the mechanisms by which Ds-26-16 confers salt tolerance to E. coli.

  2. Proteomic Analyses Reveal the Mechanism of Dunaliella salina Ds-26-16 Gene Enhancing Salt Tolerance in Escherichia coli

    PubMed Central

    Wang, Yanlong; Hu, Bin; Du, Shipeng; Gao, Shan; Chen, Xiwen; Chen, Defu

    2016-01-01

    We previously screened the novel gene Ds-26-16 from a 4 M salt-stressed Dunaliella salina cDNA library and discovered that this gene conferred salt tolerance to broad-spectrum organisms, including E. coli (Escherichia coli), Haematococcus pluvialis and tobacco. To determine the mechanism of this gene conferring salt tolerance, we studied the proteome of E. coli overexpressing the full-length cDNA of Ds-26-16 using the iTRAQ (isobaric tags for relative and absolute quantification) approach. A total of 1,610 proteins were identified, which comprised 39.4% of the whole proteome. Of the 559 differential proteins, 259 were up-regulated and 300 were down-regulated. GO (gene ontology) and KEGG (Kyoto encyclopedia of genes and genomes) enrichment analyses identified 202 major proteins, including those involved in amino acid and organic acid metabolism, energy metabolism, carbon metabolism, ROS (reactive oxygen species) scavenging, membrane proteins and ABC (ATP binding cassette) transporters, and peptidoglycan synthesis, as well as 5 up-regulated transcription factors. Our iTRAQ data suggest that Ds-26-16 up-regulates the transcription factors in E. coli to enhance salt resistance through osmotic balance, energy metabolism, and oxidative stress protection. Changes in the proteome were also observed in E. coli overexpressing the ORF (open reading frame) of Ds-26-16. Furthermore, pH, nitric oxide and glycerol content analyses indicated that Ds-26-16 overexpression increases nitric oxide content but has no effect on glycerol content, thus confirming that enhanced nitric oxide synthesis via lower intercellular pH was one of the mechanisms by which Ds-26-16 confers salt tolerance to E. coli. PMID:27135411

  3. The Effect of Astaxanthin-Rich Microalgae “Haematococcus pluvialis” and Wholemeal Flours Incorporation in Improving the Physical and Functional Properties of Cookies

    PubMed Central

    Hossain, A. K. M. Mofasser; Brennan, Margaret A.; Mason, Susan L.; Guo, Xinbo; Zeng, Xin An

    2017-01-01

    Marine-based food supplements can improve human nutrition. In an effort to modulate glycaemic response and enhance nutritional aspects, marine-derived algal food rich in astaxanthin was used in the formulation of a model food (wholemeal cookie). Astaxanthin substitution of cookies made from three flours (wheat, barley and oat) demonstrated a significant reduction in the rate of glucose released during in vitro digestion together with an increase in the total phenolic content (TPC) and antioxidant capacity of the food. The significantly (p < 0.005) lower free glucose release was observed from cookies with 15% astaxanthin, followed by 10% and then 5% astaxanthin in comparison with control cookies of each flour. Total phenolic content, DPPH radical scavenging and Oxygen Radical Absorbance Capacity (ORAC) value also notably increased with increase in astaxanthin content. The results evidence the potential use of microalgae to enhance the bioactive compounds and lower the glycaemic response of wholemeal flour cookie. PMID:28933728

  4. A New Species of Culex (Eumelanomyia) from India with Descriptions of Pupae and Larvae of Cx. pluvialis Barraud and Cx. iphis Barraud (Diptera: Culicidae)

    DTIC Science & Technology

    1977-01-01

    Mosquito Systematics Vol. 9(4) 1977 537 A New Species of Cukex (EwneZanomyiaJ from India with Descriptions of Pupae and Larvae of Cx. @via...pZuviaZis Barraud from Sri Lanka and and illustrated. (EumeZanomyiaJ mo&czni new species ftom the hitherto unknown pupae and larvae of Cx. CX. ~$his...Barraud from India are described INTRODUCTION Since publication of a revisionary study by Sirivanakarn (1972), additional material of a number of

  5. Engineering of a plasmid-free Escherichia coli strain for improved in vivo biosynthesis of astaxanthin

    PubMed Central

    2011-01-01

    Background The xanthophyll astaxanthin is a high-value compound with applications in the nutraceutical, cosmetic, food, and animal feed industries. Besides chemical synthesis and extraction from naturally producing organisms like Haematococcus pluvialis, heterologous biosynthesis in non-carotenogenic microorganisms like Escherichia coli, is a promising alternative for sustainable production of natural astaxanthin. Recent achievements in the metabolic engineering of E. coli strains have led to a significant increase in the productivity of carotenoids like lycopene or β-carotene by increasing the metabolic flux towards the isoprenoid precursors. For the heterologous biosynthesis of astaxanthin in E. coli, however, the conversion of β-carotene to astaxanthin is obviously the most critical step towards an efficient biosynthesis of astaxanthin. Results Here we report the construction of the first plasmid-free E. coli strain that produces astaxanthin as the sole carotenoid compound with a yield of 1.4 mg/g cdw (E. coli BW-ASTA). This engineered E. coli strain harbors xanthophyll biosynthetic genes from Pantoea ananatis and Nostoc punctiforme as individual expression cassettes on the chromosome and is based on a β-carotene-producing strain (E. coli BW-CARO) recently developed in our lab. E. coli BW-CARO has an enhanced biosynthesis of the isoprenoid precursor isopentenyl diphosphate (IPP) and produces β-carotene in a concentration of 6.2 mg/g cdw. The expression of crtEBIY along with the β-carotene-ketolase gene crtW148 (NpF4798) and the β-carotene-hydroxylase gene (crtZ) under controlled expression conditions in E. coli BW-ASTA directed the pathway exclusively towards the desired product astaxanthin (1.4 mg/g cdw). Conclusions By using the λ-Red recombineering technique, genes encoding for the astaxanthin biosynthesis pathway were stably integrated into the chromosome of E. coli. The expression levels of chromosomal integrated recombinant biosynthetic genes were

  6. Evaluation of Resettin® on serum hormone levels in sedentary males

    PubMed Central

    2014-01-01

    Background Comparisons of hormones such as dihydrotestosterone (DHT), estradiol (E2), and testosterone indicate their impact on metabolism and body composition. While less is known regarding DHT and E2, testosterone is an androgenic metabolic hormone capable of positively regulating a variety of anabolic and androgenic processes in the body. Accordingly, it has been postulated that the age-related reduction in serum testosterone levels leads to reductions in lean muscle mass, bone mineral density, and other physical conditions that impair physical performance and decrease quality of life. Preliminary studies suggest that key ingredients found in Resettin®/MyTosterone™, a natural supplement containing the carotenoid astaxanthin from Haematococcus pluvialis and Saw Palmetto berry lipid extract from Serenoa repens, could positively impact testosterone levels. To investigate the clinical efficacy of Resettin®, the serum profiles of testosterone, E2 and DHT in healthy sedentary males before and after Resettin® treatment were evaluated in a randomized, placebo controlled clinical trial. Method Twenty healthy, sedentary men between the ages of 21 and 70 were randomized into either an 800 mg/day or 1200 mg/day Resettin®/MyTosterone™ treatment group or lecithin, which was used as the placebo. After a 14-day treatment period, there was a 14-day washout period. After the wash-out period, participants were crossed over within their respective group to either Resettin®/MyTosterone™ or the lecithin placebo for 14 days. Results After 14 days, participants receiving 800 mg per day of Resettin® had significantly reduced baseline-subtracted serum DHT levels in comparison to the placebo control group. While after 14 days, participants receiving 1200 mg per day of Resettin® had significantly reduced baseline-subtracted serum DHT and E2 levels in comparison to the placebo control group. Moreover, participants receiving 1200 mg per day of Resettin® experienced a 38

  7. An open label, dose response study to determine the effect of a dietary supplement on dihydrotestosterone, testosterone and estradiol levels in healthy males

    PubMed Central

    Angwafor, Fru; Anderson, Mark L

    2008-01-01

    Background Maintaining endogenous testosterone (T) levels as men age may slow the symptoms of sarcopenia, andropause and decline in physical performance. Drugs inhibiting the enzyme 5α-reductase (5AR) produce increased blood levels of T and decreased levels of dihydrotestosterone (DHT). However, symptoms of gynecomastia have been reported due to the aromatase (AER) enzyme converting excess T to estradiol (ES). The carotenoid astaxanthin (AX) from Haematococcus pluvialis, Saw Palmetto berry lipid extract (SPLE) from Serenoa repens and the precise combination of these dietary supplements, Alphastat® (Mytosterone(™)), have been reported to have inhibitory effects on both 5AR and AER in-vitro. Concomitant regulation of both enzymes in-vivo would cause DHT and ES blood levels to decrease and T levels to increase. The purpose of this clinical study was to determine if patented Alphastat® (Mytosterone(™)) could produce these effects in a dose dependent manner. Methods To investigate this clinically, 42 healthy males ages 37 to 70 years were divided into two groups of twenty-one and dosed with either 800 mg/day or 2000 mg/day of Alphastat® (Mytosterone(™)) for fourteen days. Blood samples were collected on days 0, 3, 7 and 14 and assayed for T, DHT and ES. Body weight and blood pressure data were collected prior to blood collection. One-way, repeated measures analysis of variance (ANOVA-RM) was performed at a significance level of alpha = 0.05 to determine differences from baseline within each group. Two-way analysis of variance (ANOVA-2) was performed after baseline subtraction, at a significance level of alpha = 0.05 to determine differences between dose groups. Results are expressed as means ± SEM. Results ANOVA-RM showed significant within group increases in serum total T and significant decreases in serum DHT from baseline in both dose groups at a significance level of alpha = 0.05. Significant decreases in serum ES are reported for the 2000 mg/day dose

  8. Impact of exotic carps in the polyculture with indigenous carps: competition for food.

    PubMed

    Siddiquee, M M R; Rahman, M F; Jahan, N; Jalal, K C A; Amin, S M N; Arshad, A

    2012-06-15

    The fingerlings of indigenous carps such as catla (Catla catla), rohu (Labeo rohita) and mrigal (Cirrhinus mrigala) with exotic carps such as silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis) and mirror carp (Cyprinus carpio) were cultured together in a fish pond at Bangladesh Agricultural University, Mymensingh, in order to determine the food electivity, dietary overlap and food competition among indigenous major carps and exotic carps. Phytoplankton (Chlorophyceae, Cyanophyceae), zooplankton (rotifers) were the dominant groups in the cultured pond. Chlorophyceae was dominant in the diet of rohu. Chlorophyceae and rotifers were the preferred food of catla. Mrigal preferred phytoplankton than zooplankton. Rohu showed positive electivity for zooplankton. Silver carp consumed large quantity of phytoplankton and also preferred rotifers. Chlorophyceae was the dominant food group in the diet of bighead. Mirror carp also preferred plant food organisms dominated by Chlorophyceae. Bighead had positive trends towards phytoplankton. Both mrigal and mirror carp had positive electivity towards phytoplankton. The higher level of dietary overlap occurred between rohu and silver carp followed by between rohu and bighead carp and between catla and silver carp. The lowest level of dietary overlaps occurred between rohu and mirror carp.

  9. Quantification of nutrient-replete growth rates in five-ion hyperspace for Chlorella vulgaris (Trebouxiophyceae) and Peridinium cinctum (Dinophyceae).

    USDA-ARS?s Scientific Manuscript database

    The effects of five ions, NO3-, PO43-, K+, Na+ and Cl- on growth rates and cell densities were quantified for Chlorella vulgaris (Chlorophycea) and Peridinium cinctum (Dinophycea) in batch cultures. A five dimensional experimental design, the five component mixture design projected across a total i...

  10. Environmental Assessment for the General Plan and Maintenance of Patrick Air Force Base, Florida

    DTIC Science & Technology

    2005-05-01

    3-21 3.6.2.8 Piping Plover ...americana Black-bellied plover Pluvialis squatarola Semipalmated plover Charadrius semipalmatus Killdeer Charadrius vociferus Wouldet Catoptrophorus...Salt Marsh Snake* Nerodia clarkii taeniata T T Birds Roseate Spoonbill* Ajaia ajaja SSC Piping Plover * Charadrius melodus T T Little Blue

  11. 50 CFR 92.22 - Subsistence migratory bird species.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... gathering is permitted. (7) Black Brant (Branta bernicla nigricans)—except no egg gathering is permitted in...) Black Scoter (Melanitta nigra). (28) Long-tailed Duck (Clangula hyemalis). (29) Bufflehead (Bucephala... (Grus canadensis). (2) (g) Family Charadriidae. (1) Black-bellied Plover (Pluvialis squatarola)....

  12. 50 CFR 92.22 - Subsistence migratory bird species.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... gathering is permitted. (7) Black Brant (Branta bernicla nigricans)—except no egg gathering is permitted in...) Black Scoter (Melanitta nigra). (28) Long-tailed Duck (Clangula hyemalis). (29) Bufflehead (Bucephala... (Grus canadensis). (2) (g) Family Charadriidae. (1) Black-bellied Plover (Pluvialis squatarola)....

  13. 50 CFR 92.22 - Subsistence migratory bird species.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... gathering is permitted. (7) Black Brant (Branta bernicla nigricans)—except no egg gathering is permitted in...) Black Scoter (Melanitta nigra). (28) Long-tailed Duck (Clangula hyemalis). (29) Bufflehead (Bucephala... (Grus canadensis). (2) (g) Family Charadriidae. (1) Black-bellied Plover (Pluvialis squatarola)....

  14. Seasonal variations and biodiversity of phytoplankton in Harsool-Savangi dam, Aurangabad, India.

    PubMed

    Shinde, S E; Pathan, T S; Sonawane, D L

    2012-05-01

    The present study concerns seasonal variations, correlation coefficient and biodiversity indices of phytoplankton during January to December, 2008 in the Harsool-Savangi dam, Aurangabad, India. A total of 35 genera were recorded out of which 15 were Chlorophyceae, 7 Bacillariophyceae, 7 Cyanophyceae and 6 Euglenophyceae. Present study revealed maximum percentage wise compositions of Chlorophyceae at north site 41.91%, Bacillariophyceae at west site 32.70%, Cyanophyceae at south site 19.50% and Euglenophyceae at west site 11.47%. Minimum percentage wise compositions Chlorophyceae at south site 37.80%, Bacillariophyceae at east site 28.15%, Cyanophyceae at west site 17.47% and Euglenophyceae at north site 10.57%. Margalef's index (R1) and Menhinick index (R2) values (4.12 and 0.56) were found to be highest at south site and lowest values (3.77 and 0.38) were found at north site. Simpson's index (I) values (0.30) were found to be the highest at north site and lowest values (0.29) were found at south, east, and west sites. Shannon-Weiner index (H') values (1.26) were found to be the highest at south, east, and west sites and lowest values (1.24) were found at north site. Maximum species evenness was recorded at south site; minimum at north site. Maximum population density of Chlorophyceae, Bacillariophyceae, Cyanophyceae and Euglenophyceae (1923, 1173, 889 and 541 organisms I(-1)) were recorded at north site in summer and minimum (108,195, 67 and 24 organisms l(-1)) were recorded at south site in monsoon, respectively.

  15. [From algae to "functional foods"].

    PubMed

    Vadalà, M; Palmieri, B

    2015-01-01

    In the recent years, a growing interest for nutraceutical algae (tablets, capsules, drops) has been developed, due to their effective health benefits, as a potential alternative to the classic drugs. This review explores the use of cyanobacterium Spirulina, the microalgae Chlorella, Dunaliella, Haematococcus, and the macroalgae Klamath, Ascophyllum, Lithothamnion, Chondrus, Hundaria, Glacilaria, Laminaria, Asparagopsis, Eisenia, Sargassum as nutraceuticals and dietary supplements, in terms of production, nutritional components and evidence-based health benefits. Thus, our specific goals are: 1) Overview of the algae species currently used in nutraceuticals; 2) Description of their characteristics, action mechanisms, and possible side effects; 3) Perspective of specific algae clinical investigations development.

  16. Diatoms and aquatic palynomorphs in surface sediments of the White Sea bays as indicators of sedimentation in marginal filters of rivers

    NASA Astrophysics Data System (ADS)

    Polyakova, Ye. I.; Novichkova, Ye. A.; Lisitzin, A. P.; Shevchenko, V. P.; Kravchishina, M. D.

    2016-03-01

    Diatom algae, aquatic palynomorphs, and the grain-size of surface sediments from bays of the White Sea were investigated in a program dedicated to the study of marginal filters (MF) in the Severnaya Dvina, Onega, and Kem rivers. Three microalgal assemblages are established in surface sediments, which replace each other successively with distance from river mouths and are characterized by a gradual decrease in a share of freshwater species of diatoms and Chlorophyceae algae, significantly varying concentrations of marine diatoms and dinocysts due to changes in water salinity, grain-size composition of sediments, quantitative distribution of suspended particulate matter (SPM), and water productivity at different marginal filter stages.

  17. Access the toxic effect of the antibiotic cefradine and its UV light degradation products on two freshwater algae.

    PubMed

    Chen, J Q; Guo, R X

    2012-03-30

    Two common freshwater algae Microcystis aeruginosa and Scenedesmus obliquus were employed as test organism to evaluate the toxic effects of the widely used antibiotic, cefradine. In general, cefradine had significantly toxic effect on population growth and chlorophyll-a accumulation of two algae and the cyanophyceae was more sensitive than the chlorophyceae. In addition, cefradine UV light degraded products had adverse effect on M. aeruginosa's growth and chlorophyll-a accumulation. In comparison, even if S. obliquus had growth ability when exposed to cefradine UV light-degradation products, the algal photosynthesis function was also disrupted.

  18. Occurrence of non-hydrolysable amides in the macromolecular constituent of Scenedesmus quadricauda cell wall as revealed by [sup 15]N NMR: Origin of n-alkylnitriles in pyrolysates of ultralaminai-containing kerogens

    SciTech Connect

    Derenne, S.; Largeau, C. ); Taulelle, F. )

    1993-02-01

    New structures, termed ultralaminae, were recently shown to occur in kerogens from numerous oil shales and source rocks. Morphological and chemical studies revealed that ultralaminae originate from the selective preservation of the non-hydrolysable biomacromolecules (algaenans) building up the thin outer walls of several Chlorophyceae (green microalgae) including the cosmopolitan general Scenedesmus and Chlorella. The chemical correlation between such algaenans and fossil ultralaminae was mainly based on the production, on pyrolysis, of nitrogen compounds, n-alkylnitriles, with specific distributions depending on the lacustrine of marine origin of the considered samples. In addition, these bio-and geopolymers were characterized by quite high N levels.

  19. Microalgal fiber-optic biosensors for water quality monitoring

    NASA Astrophysics Data System (ADS)

    Orellana, Guillermo; Villén, Laura; Haigh, David; Maneiro, Emilia; Marvá, Fernando; Costas, Eduardo

    2007-07-01

    Novel fiber-optic biosensors have been developed for the analysis of pesticides in water based on Chlorophyceae microalgae immobilized into a porous silicone layer as recognition element, and on measurements of the photogenerated O II as chemical transducer. The inhibition of O II production by the photosynthetic green algae in the presence of the pesticide (simazine) was used as the biological signal. Luminescent thin films and a dedicated optoelectronic unit based on emission phase-shift measurements provide the tools for the sensitive O II measurements. Fluctuation analysis allows selection of sensitive and resistant microalgae mutants without genetic manipulation for maximum biosensing selectivity.

  20. Inorganic and organic contaminants in Alaskan shorebird eggs.

    PubMed

    Saalfeld, David T; Matz, Angela C; McCaffery, Brian J; Johnson, Oscar W; Bruner, Phil; Lanctot, Richard B

    2016-05-01

    Many shorebird populations throughout North America are thought to be declining, with potential causes attributed to habitat loss and fragmentation, reduced prey availability, increased predation, human disturbance, and increased exposure to environmental pollutants. Shorebirds may be particularly vulnerable to contaminant exposure throughout their life cycle, as they forage primarily on invertebrates in wetlands, where many contaminants accumulate disproportionately in the sediments. Therefore, it is important to document and monitor shorebird populations thought to be at risk and assess the role that environmental contaminants may have on population declines. To investigate potential threats and provide baseline data on shorebird contaminant levels in Alaskan shorebirds, contaminant concentrations were evaluated in shorebird eggs from 16 species residing in seven geographic distinct regions of Alaska. Similar to previous studies, low levels of most inorganic and organic contaminants were found, although concentrations of several inorganic and organic contaminants were higher than those of previous studies. For example, elevated strontium levels were observed in several species, especially black oystercatcher (Haematopus bachmani) sampled in Prince William Sound, Alaska. Additionally, contaminant concentrations varied among species, with significantly higher concentrations of inorganic contaminants found in eggs of pectoral sandpiper (Calidris melanotos), semipalmated sandpiper (Calidris pusilla), black oystercatcher, and bar-tailed godwit (Limosa lapponica). Similarly, significantly higher concentrations of some organic contaminants were found in the eggs of American golden plover (Pluvialis dominica), black-bellied plover (Pluvialis squatarola), pacific golden plover (Pluvialis fulva), bar-tailed godwit, and semipalmated sandpiper. Despite these elevated levels, current concentrations of contaminants in shorebird eggs suggest that breeding environments are

  1. Organochlorines, mercury, and selenium in wintering shorebirds from Washington and California

    USGS Publications Warehouse

    Custer, T.W.; Myers, J.P.

    1990-01-01

    Dunlins Caldris alpina , and black-bellied plovers, Pluvialis squatarola , were collected in Washington and California during the winter of 1984-85; long-billed dowitchers, Limnodromus scolopaceus , were collected in California. Pooled breast muscles were analyzed for organochlorines and pooled livers for mercury and selenium. DDE was detected in all eight dunlin, three of five dowitcher, and two of nine plover muscle pools. Estimated DDE concentrations in dunlin carcasses at two sites in California were greater than 3 ppm wet wt, a dietary concentration associated with eggshell thinning and decreased reproductive success in raptors. Detectable concentrations of mercury and selenium were found in all liver pools.

  2. Identification of anticoagulant activities in salivary gland extracts of four horsefly species (Diptera, tabanidae).

    PubMed

    Kazimírová, M; Sulanová, M; Kozánek, M; Takác, P; Labuda, M; Nuttall, P A

    2001-01-01

    Anticoagulant activities against the extrinsic and intrinsic coagulation pathways were identified in salivary gland extracts (SGE) prepared from four tabanids (Hybomitra muehlfeldi, Tabanus autumnalis, Haematopota pluvialis, Heptatoma pellucens). All extracts prolonged human plasma clotting time in a dose-dependent manner and inhibited thrombin activity in the chromogenic substrate assay. Horsefly SGE did not inhibit factor Xa. Partial purification of SGE proteins using reversed-phase high-performance liquid chromatography revealed species-specific differences in the elution profiles and range of fractions with anticoagulant activities. Copyright 2002 S. Karger AG, Basel

  3. Determining in situ periphyton community responses to nutrient and atrazine gradients via pigment analysis.

    PubMed

    Dalton, Rebecca L; Boutin, Céline; Pick, Frances R

    2015-05-15

    Agrochemicals, including fertilizers and herbicides, are significant contributors of non-point source pollution to surface waters and have the potential to negatively affect periphyton. We characterized periphyton communities using pigment markers to assess the effects of nutrient enrichment and the herbicide atrazine with in situ experimental manipulations and by examining changes in community structure along existing agrochemical gradients. In 2008, the addition of nutrients (20 mg/L nitrate and 1.25 mg/L reactive phosphate), atrazine (20 μg/L) and a combination of both nutrients and atrazine had no significant effect on periphyton biomass or community structure in a stream periphytometer experiment. In 2009, similar experiments with higher concentrations of atrazine (200 μg/L) at two stream sites led to some minor effects. In contrast, at the watershed scale (2010) periphyton biomass (mg/m(2) chlorophyll a) increased significantly along correlated gradients of nitrate and atrazine but no direct effects of reactive phosphate were observed. Across the watershed, the average periphyton community was composed of Bacillariophyceae (60.9%), Chlorophyceae (28.1%), Cryptophyceae (6.9%) and Euglenophyceae (4.1%), with the Bacillariophyceae associated with high turbidity and the Chlorophyceae with nitrate enrichment. Overall, effects of nitrate on periphyton biomass and community structure superseded effects of reactive phosphate and atrazine. Copyright © 2015. Published by Elsevier B.V.

  4. Sterols of the green-pigmented, aberrant plastid dinoflagellate, Lepidodinium chlorophorum (Dinophyceae).

    PubMed

    Leblond, Jeffrey D; Lasiter, Andrew D

    2012-01-01

    Lepidodinium chlorophorum is a green-pigmented dinoflagellate with an aberrant, tertiary plastid of chlorophyte ancestry rather than the typical red algal, secondary endosymbiont found in the vast majority of photosynthetic dinoflagellates. To date, only one published study exists on the galactolipids of L. chlorophorum, with nothing known about other lipid classes, including sterols. Our objectives were to examine the sterol composition of L. chlorophorum to determine if it produces any unique sterols with the potential to serve as biomarkers, and to compare it to members of the Chlorophyceae to determine if it has inherited any signature green algal sterols from its chlorophyte-derived endosymbiont. We have found that L. chlorophorum produces 6 sterols, all with a 4α-methyl substituent and none of which are known to occur in the Chlorophyceae. Rather, the sterols produced by L. chlorophorum place it within a group of dinoflagellates that have the common dinoflagellate sterols, dinosterol and dinostanol, as part of their sterol composition. Copyright © 2011 Elsevier GmbH. All rights reserved.

  5. Microalgae population dynamics in photobioreactors with secondary sewage effluent as culture medium

    PubMed Central

    Marchello, Adriano E.; Lombardi, Ana T.; Dellamano-Oliveira, Maria José; de Souza, Clovis W.O.

    2015-01-01

    Nitrogen and phosphorus present in sewage can be used for microalgae growth, possibiliting cost reduction in the production of microalgae at the same time that it decreases the eutrophication potential of the effluent. This research aimed at monitoring the native community of microalgae and coliform bacteria in a secondary effluent from anaerobic municipal sewage treatment. Two treatments (aerated and non-aerated) were performed to grow microalgae under semi-controlled conditions in semi-closed photobioreactors in a greenhouse. The results showed no significant pH and coliforms (total and Escherichia coli ) variation between treatments. Nutrient concentrations were reduced supporting microalgae growth up to 10 7 cells.mL −1 independent of aeration. Exponential growth was obtained from the first day for the non-aerated, but a 5 day lag phase of growth was obtained for the aerated. Chlorella vulgaris was the dominant microalgae (99.9%) in both treatments. In the aerated, 5 algae classes were detected (Chlorophyceae, Cyanophyceae, Chrysophyceae, Bacillariophyceae and Euglenophyceae), with 12 taxa, whereas in the non-aerated, 2 classes were identified (Chlorophyceae and Cyanophyceae), with 5 taxa. We concluded that effluent is viable for microalgae growth, especially Chlorella vulgaris, at the same time that the eutrophication potential and coliforms are decreased, contributing for better quality of the final effluent. PMID:26221091

  6. About the interest of a zooplankton compartment in pond systems: methodology to study the growth kinetic of Daphnia pulex on Scenedesmus sp.

    PubMed

    Liady, M N D; Tangou, T T; Fiogbe, E D; Cauchie, H-M; Vasel, J-L

    2015-01-01

    A reliable characterization of cladocerans' growth kinetic on their substrates is crucial for the estimation of their biochemical conversion rate in pond models. Although many studies reported cladocerans' growth inhibitions by high chlorophyceae contents, their growth kinetics had continued to be described in many pond system models by Monod-type kinetic, which describes growth saturation by high substrate contents, but fails to explain the disappearance of cladocerans observed during chlorophyceae's bloom periods. This study aimed to develop a methodology and assess whether growth-inhibition-type models used to describe microbial growth kinetics can be applicable to cladocerans. Experiments were carried out using Daphnia pulex populations and Scenedesmus sp. First, biomass of D. pulex was measured through digital image processing (DIP) during growth experiments. Then, three candidate models (i.e., Andrews, Edward and Haldane models), along with the Monod model, were fitted to the observed data and compared. The results showed that the DIP technique provided reliable results for estimating the biomass of D. pulex. Our findings show that the candidate growth inhibition-type models satisfactorily described D. pulex's growth kinetic (86% variance accounted for). Scenesdemus sp. were not strong inhibitors of the growth of D. pulex (high inhibition constant and low half-saturation constant found).

  7. A consensus secondary structure of ITS2 in the chlorophyta identified by phylogenetic reconstruction.

    PubMed

    Caisová, Lenka; Marin, Birger; Melkonian, Michael

    2013-07-01

    The definition of species plays a pivotal role in biology. It has been proposed that Compensatory Base Changes (CBCs) in the fast-evolving Internal Transcribed Spacer 2 (ITS2) correlate with speciation and thus can be used to distinguish species. The applicability of CBC - based species concepts using ITS2, however, rests on the homology of the investigated ITS2 positions. We studied the ITS2 molecule of 147 strains of Chlorophyceae (Chlorophyta, Viridiplantae) including 26 new sequences in the order Chaetophorales, and compared their secondary structures to ITS2 in the sister class Ulvophyceae, represented by the order Ulvales. Using a phylogenetic/comparative approach, it was possible to identify 1) the first consensus structure model of the ITS2 molecule that can be applied to two classes of green algae [Ulvophyceae (Ulvales), Chlorophyceae] and 2) landmarks (the spacer regions separating the ITS2 Helices) for more robust prediction of the secondary structures in green algae. Moreover, we found that CBCs in homologous positions in these 147 strains (representing 115 validly described species) are either completely absent or mostly associated with internal branches representing higher order taxonomic levels (genera, families, orders). As reported for the Ulvales, CBCs are not diagnostic at the species level in the dataset used.

  8. Derivation of Ecological Protective Concentration using the Probabilistic Ecological Risk Assessment applicable for Korean Water Environment: (I) Cadmium

    PubMed Central

    Nam, Sun-Hwa; Lee, Woo-Mi

    2012-01-01

    Probabilistic ecological risk assessment (PERA) for deriving ecological protective concentration (EPC) was previously suggested in USA, Australia, New Zealand, Canada, and Netherland. This study suggested the EPC of cadmium (Cd) based on the PERA to be suitable to Korean aquatic ecosystem. First, we collected reliable ecotoxicity data from reliable data without restriction and reliable data with restrictions. Next, we sorted the ecotoxicity data based on the site-specific locations, exposure duration, and water hardness. To correct toxicity by the water hardness, EU’s hardness corrected algorithm was used with slope factor 0.89 and a benchmark of water hardness 100. EPC was calculated according to statistical extrapolation method (SEM), statistical extrapolation methodAcute to chronic ratio (SEMACR), and assessment factor method (AFM). As a result, aquatic toxicity data of Cd were collected from 43 acute toxicity data (4 Actinopterygill, 29 Branchiopoda, 1 Polychaeta, 2 Bryozoa, 6 Chlorophyceae, 1 Chanophyceae) and 40 chronic toxicity data (2 Actinopterygill, 23 Branchiopoda, 9 Chlorophyceae, 6 Macrophytes). Because toxicity data of Cd belongs to 4 classes in taxonomical classification, acute and chronic EPC (11.07 μg/l and 0.034 μg/l, respectively) was calculated according to SEM technique. These values were included in the range of international EPCs. This study would be useful to establish the ecological standard for the protection of aquatic ecosystem in Korea. PMID:24278601

  9. Microalgae population dynamics in photobioreactors with secondary sewage effluent as culture medium.

    PubMed

    Marchello, Adriano E; Lombardi, Ana T; Dellamano-Oliveira, Maria José; de Souza, Clovis W O

    2015-03-01

    Nitrogen and phosphorus present in sewage can be used for microalgae growth, possibiliting cost reduction in the production of microalgae at the same time that it decreases the eutrophication potential of the effluent. This research aimed at monitoring the native community of microalgae and coliform bacteria in a secondary effluent from anaerobic municipal sewage treatment. Two treatments (aerated and non-aerated) were performed to grow microalgae under semi-controlled conditions in semi-closed photobioreactors in a greenhouse. The results showed no significant pH and coliforms (total and Escherichia coli ) variation between treatments. Nutrient concentrations were reduced supporting microalgae growth up to 10 (7) cells.mL (-1) independent of aeration. Exponential growth was obtained from the first day for the non-aerated, but a 5 day lag phase of growth was obtained for the aerated. Chlorella vulgaris was the dominant microalgae (99.9%) in both treatments. In the aerated, 5 algae classes were detected (Chlorophyceae, Cyanophyceae, Chrysophyceae, Bacillariophyceae and Euglenophyceae), with 12 taxa, whereas in the non-aerated, 2 classes were identified (Chlorophyceae and Cyanophyceae), with 5 taxa. We concluded that effluent is viable for microalgae growth, especially Chlorella vulgaris, at the same time that the eutrophication potential and coliforms are decreased, contributing for better quality of the final effluent.

  10. Comparative effects of the herbicides chlortoluron and mesotrione on freshwater microalgae.

    PubMed

    Moro, Claire Valiente; Bricheux, Genevieve; Portelli, Christophe; Bohatier, Jacques

    2012-04-01

    Extensive use of herbicides in agriculture is accompanied by the risk of environmental contamination of aquatic ecosystems. The present study shows the effects of the herbicides chlortoluron and mesotrione on three microalgae species: two chlorophyceae (Pediastrum tetras, Ankistrodesmus fusiformis) and one diatom (Amphora coffeaeformis). The authors calculated the IC50 for one chlorophyceae and the diatom. The order of toxicity (median inhibitory concentration [IC50]) for mesotrione was A. coffeaeformis (13.1 mg/L) > A. fusiformis (56.1 mg/L) and A. fusiformis (0.05 mg/L) > A. coffeaeformis (0.08 mg/L) for chlortoluron. The impact of herbicides applied at 0.2 mg/L was then examined in Erlenmeyer flasks by monitoring for growth, pigment content, and metabolic activity. Algal responses varied widely according to species and herbicide. For example, chlortoluron showed a significant inhibitory effect on the growth of A. coffeaeformis, whereas mesotrione induced an increase in cellular density in A. fusiformis. Other cellular parameters, such as pigment content in P. tetras, were stimulated by both herbicides. The results obtained confirmed that microalgae cultures are clearly affected by acute and chronic exposition to herbicides. Further monitoring should be carried out in the field to assess the impact of sublethal levels of toxicity and the growth-enhancing effects of mesotrione and chlortoluron on natural algae communities. Copyright © 2012 SETAC.

  11. Biodiversity of microalgae in Western and Eastern Ghats, India.

    PubMed

    Suresh, A; Kumar, R Praveen; Dhanasekaran, D; Thajuddin, N

    2012-10-01

    The systematic study was conducted on the microalgal flora of Western Ghats and other parts of Eastern Ghats revealed a rich wetland algal resource for biotechnological exploration. The present study reveals with the diversity of microalgal flora in the region of Kodaikanal (10 degrees 14' N, 77 degrees 28' E), Gudalur (9 degrees 19'N 77 degrees 12'E), Agasthiyar falls (9 degrees 58'N, 78 degrees 10'E) and Kolli hills (10 degrees 12'N, 77 degrees 56'E) located in Western and Eastern Ghats of Tamilnadu, India collected in May 2011. In total, 97 species of micro algae belonging to three taxonomic groups were identified, of which 41 species belonging to Cyanophyceae, 38 species from Chlorophyceae and 18 species from Bacillariophyceae. The predominant species in Cyanophyceae were Aphanothece microscopica, Chroococcus minutus, Coelospharium dubium, Hydrococcus rivularism, Oscillatoria princeps, Nostoc muscorum, Nostoc puncteforme, Nostoc commune, Gleotricha gausii, Calothrix braunii, Rivellaria sp., Tolypothrix tenuis, Scytonema schmidtii, whereas in Chlorophyceae, Chlorella sp., Scenedesmus sp., Pediastrum duplex, Cosmarium consperum, Euastrum elagans, Micrasterias americana and in Bacillariophyceae, Navicula hallophyla, Rhophaldia gebrella, Fragellaria intermedia, Pinnularia virdis, Nitzchia palliate. Physicochemical nature of water samples were analyzed and correlated with the total microalgal diversity. Based on the correlation coefficient data, the micro algae showed positive relationship with dissolved oxygen, salinity, nutrients and negative relationship with temperature and turbidity. The species diversity index (H'), Species Richness (SR) and species evenness (J') were calculated and analyzed for microalgal population dynamic variation in the Western and Eastern Ghats.

  12. Distinctive architecture of the chloroplast genome in the chlorophycean green alga Stigeoclonium helveticum.

    PubMed

    Bélanger, Anne-Sophie; Brouard, Jean-Simon; Charlebois, Patrick; Otis, Christian; Lemieux, Claude; Turmel, Monique

    2006-11-01

    The chloroplast genome has experienced many architectural changes during the evolution of chlorophyte green algae, with the class Chlorophyceae displaying the lowest degree of ancestral traits. We have previously shown that the completely sequenced chloroplast DNAs (cpDNAs) of Chamydomonas reinhardtii (Chlamydomonadales) and Scenedesmus obliquus (Sphaeropleales) are highly scrambled in gene order relative to one another. Here, we report the complete cpDNA sequence of Stigeoclonium helveticum (Chaetophorales), a member of a third chlorophycean lineage. This genome, which encodes 97 genes and contains 21 introns (including four putatively trans-spliced group II introns inserted at novel sites), is remarkably rich in derived features and extremely rearranged relative to its chlorophycean counterparts. At 223,902 bp, Stigeoclonium cpDNA is the largest chloroplast genome sequenced thus far, and in contrast to those of Chlamydomonas and Scenedesmus, features no large inverted repeat. Interestingly, the pattern of gene distribution between the DNA strands and the bias in base composition along each strand suggest that the Stigeoclonium genome replicates bidirectionally from a single origin. Unlike most known trans-spliced group II introns, those of Stigeoclonium exhibit breaks in domains I and II. By placing our comparative genome analyses in a phylogenetic framework, we inferred an evolutionary scenario of the mutational events that led to changes in genome architecture in the Chlorophyceae.

  13. Repercussions of salinity changes and osmotic stress in marine phytoplankton species

    NASA Astrophysics Data System (ADS)

    D'ors, A.; Bartolomé, M. C.; Sánchez-Fortún, S.

    2016-06-01

    The short-term effect of low salinity was studied using laboratory protocols on some coastal phytoplankton species such as chlorophycea Tetraselmis suecica, among diatom the strain Nitzschia N1c1 and dinoflagellates Alexandrium minutum and Prorocentrum lima. All of cultures were exposed to low salinities, and cell growth rate, photosynthetic quantum yield (ΦPSII), and gross photosynthesis (Pg) were analyzed. Growth rate inhibition was similar in all species, and all of them also tolerate short-term exposures to salinities in the range 5-35. There were no significant differences between ΦPSII and Pg endpoints from Tetraselmis suecica and Nitzschia sp., while Alexandrium minutum and Prorocentrum lima displayed a higher affectation rate on Pg than on ΦPSII activity. The influence of low salinity was higher on respiration in T. suecica, while both dinoflagellates had higher net photosynthesis. Nitzschia sp. exhibited similar involvement of the two photosynthetic parameters. Therefore, although the four phytoplankton monocultures studied are able to survive in internal areas of estuaries under low salinity conditions, the photosynthetic activity is more affected than the growth rate in all phytoplankton communities studied except in chlorophycea T. suecica, which has increased tolerance for this salinity decrease.

  14. Suitability of Phytosterols Alongside Fatty Acids as Chemotaxonomic Biomarkers for Phytoplankton

    PubMed Central

    Taipale, Sami J.; Hiltunen, Minna; Vuorio, Kristiina; Peltomaa, Elina

    2016-01-01

    The composition and abundance of phytoplankton is an important factor defining ecological status of marine and freshwater ecosystems. Chemotaxonomic markers (e.g., pigments and fatty acids) are needed for monitoring changes in a phytoplankton community and to know the nutritional quality of seston for herbivorous zooplankton. Here we investigated the suitability of sterols along with fatty acids as chemotaxonomic markers using multivariate statistics, by analyzing the sterol and fatty acid composition of 10 different phytoplankton classes including altogether 37 strains isolated from freshwater lakes. We were able to detect a total of 47 fatty acids and 29 sterols in our phytoplankton samples, which both differed statistically significantly between phytoplankton classes. Due to the high variation of fatty acid composition among Cyanophyceae, taxonomical differentiation increased when Cyanophyceae were excluded from statistical analysis. Sterol composition was more heterogeneous within class than fatty acids and did not improve separation of phytoplankton classes when used alongside fatty acids. However, we conclude that sterols can provide additional information on the abundance of specific genera within a class which can be generated by using fatty acids. For example, whereas high C16 ω-3 PUFA (polyunsaturated fatty acid) indicates the presence of Chlorophyceae, a simultaneous high amount of ergosterol could specify the presence of Chlamydomonas spp. (Chlorophyceae). Additionally, we found specific 4α-methyl sterols for distinct Dinophyceae genera, suggesting that 4α-methyl sterols can potentially separate freshwater dinoflagellates from each other. PMID:26973664

  15. Derivation of Ecological Protective Concentration using the Probabilistic Ecological Risk Assessment applicable for Korean Water Environment: (I) Cadmium.

    PubMed

    Nam, Sun-Hwa; Lee, Woo-Mi; An, Youn-Joo

    2012-06-01

    Probabilistic ecological risk assessment (PERA) for deriving ecological protective concentration (EPC) was previously suggested in USA, Australia, New Zealand, Canada, and Netherland. This study suggested the EPC of cadmium (Cd) based on the PERA to be suitable to Korean aquatic ecosystem. First, we collected reliable ecotoxicity data from reliable data without restriction and reliable data with restrictions. Next, we sorted the ecotoxicity data based on the site-specific locations, exposure duration, and water hardness. To correct toxicity by the water hardness, EU's hardness corrected algorithm was used with slope factor 0.89 and a benchmark of water hardness 100. EPC was calculated according to statistical extrapolation method (SEM), statistical extrapolation methodAcute to chronic ratio (SEMACR), and assessment factor method (AFM). As a result, aquatic toxicity data of Cd were collected from 43 acute toxicity data (4 Actinopterygill, 29 Branchiopoda, 1 Polychaeta, 2 Bryozoa, 6 Chlorophyceae, 1 Chanophyceae) and 40 chronic toxicity data (2 Actinopterygill, 23 Branchiopoda, 9 Chlorophyceae, 6 Macrophytes). Because toxicity data of Cd belongs to 4 classes in taxonomical classification, acute and chronic EPC (11.07 μg/l and 0.034 μg/l, respectively) was calculated according to SEM technique. These values were included in the range of international EPCs. This study would be useful to establish the ecological standard for the protection of aquatic ecosystem in Korea.

  16. A new species of Pristimantis (Amphibia, Anura, Craugastoridae) from the foothills of the Andes in Manu National Park, southeastern Peru.

    PubMed

    Shepack, Alexander; von May, Rudolf; Ttito, Alex; Catenazzi, Alessandro

    2016-01-01

    We describe a new species of Pristimantis from the humid sub-montane forest of the Región Cusco in Peru. Pristimantis pluvialis sp. n. was collected in the Kosñipata and Entoro valleys at elevations from 740 to 1110 m a.s.l., near the borders of Manu National Park and within the Huachiperi Haramba Queros Conservation Concession. The new species can be distinguished from other members of the genus Pristimantis by its rostral tubercle, smooth dorsal skin, and by its advertisement call. Pristimantis lacrimosus and Pristimantis waoranii superficially most resemble the new species, but Pristimantis pluvialis sp. n. differs from both species by having a rostral tubercle (absent in Pristimantis waoranii and variable in Pristimantis lacrimosus) and larger size, from Pristimantis lacrimosus by its call emitted at a lower frequency, and from Pristimantis waoranii for its dorsal coloration with dark markings. Two other species have partially overlapping distributions and resemble the new species, Pristimantis mendax and Pristimantis olivaceus, but they produce advertisement calls with much higher dominant frequencies than the advertisement call of the new species. Furthermore, Pristimantis mendax differs from the new species by lacking a rostral tubercle and by having a sigmoid inner tarsal fold, whereas Pristimantis olivaceus differs by being smaller and by having dorsal skin shagreen with scattered tubercles. The new species has snout-vent length of 21.8-26.9 mm in males (n = 12) and 28.8 mm in a single female.

  17. Response of Tabanidae (Diptera) to different natural attractants.

    PubMed

    Krcmar, Stjepan; Mikuska, Alma; Merdić, Enrih

    2006-12-01

    The response of female tabanids to natural attractants was studied in the Monjoros Forest along the Nature Park Kopacki rit in eastern Croatia. Tabanids were caught in canopy traps baited with either aged cow, horse, sheep, or pig urine and also in unbaited traps. Tabanids were collected in a significantly higher numbers in traps baited with natural attractants compared to unbaited traps. The number of females of Tabanus bromius, Tabanus maculicornis, Tabanus tergestinus, and Hybomitra bimaculata collected from canopy traps baited with cow urine and traps baited with other natural attractants differed significantly. Females of Haematopota pluvialis were also collected more frequently in canopy traps baited with aged cow urine than in those with aged horse urine, but this difference was not significant. However, the number of females of Haematopota pluvialis collected from canopy traps baited with other natural attractants (sheep and pig urine) differed significantly when compared with aged cow urine baited traps. Canopy traps baited with aged cow urine collected significantly more Tabanus sudeticus than did traps baited with aged pig urine. Finally, the aged cow urine baited canopy traps collected 51 times more tabanids than unbaited traps, while aged horse, aged sheep, and aged pig urine baited traps collected 36, 30, and 22 times as many tabanids, respectively, than unbaited traps.

  18. Seasonal abundance of horse flies (Diptera: Tabanidae) from two locations in eastern Croatia.

    PubMed

    Krcmar, Stjepan

    2005-12-01

    A total of 10,539 tabanid horse flies from 22 species and five genera was collected in the Tikves forest within the Kopacki rit Nature Park in eastern Croatia. Seasonal abundance was analyzed for the six most abundant species. Tabanus maculicornis, Tabanus tergestinus, and Haematopota pluvialis reached their highest peak abundance in the fourth week of June. Atylotus loewianus and Tabanus bromius reached their highest peak of abundance in the first week of August, whereas Tabanus sudeticus reached its maximum abundance in the third week of July. Horse flies also were collected once a week on the pasture at Petrijevci from mid-May to mid-September during 1993. Paired collections were made from a Malaise trap and from a horse by using a sweep net. A total of 2,867 tabanids belonging to 26 species was collected. The number of tabanids collected on horses was much higher than the total captured with Malaise traps. On their natural host (horse), 2.6 times more tabanids were collected than in the traps. Seasonal abundance was analyzed only for the eight most abundant species. Chrysops paralellogrammus, Tabanus autumnalis, Tabanus bromius, Tabanus tergestinus, Haematopota pluvialis, and Haematopota subcylindrica all reached their highest peak of abundance in the second week of July, whereas Tabanus maculicornis reached the maximal peak of abundance in the third week of June. Seasonal meteorological variability that occurs periodically from one year to another has a significant influence on the maximal peaks of tabanid abundance.

  19. A new species of Pristimantis (Amphibia, Anura, Craugastoridae) from the foothills of the Andes in Manu National Park, southeastern Peru

    PubMed Central

    Shepack, Alexander; von May, Rudolf; Ttito, Alex; Catenazzi, Alessandro

    2016-01-01

    Abstract We describe a new species of Pristimantis from the humid sub-montane forest of the Región Cusco in Peru. Pristimantis pluvialis sp. n. was collected in the Kosñipata and Entoro valleys at elevations from 740 to 1110 m a.s.l., near the borders of Manu National Park and within the Huachiperi Haramba Queros Conservation Concession. The new species can be distinguished from other members of the genus Pristimantis by its rostral tubercle, smooth dorsal skin, and by its advertisement call. Pristimantis lacrimosus and Pristimantis waoranii superficially most resemble the new species, but Pristimantis pluvialis sp. n. differs from both species by having a rostral tubercle (absent in Pristimantis waoranii and variable in Pristimantis lacrimosus) and larger size, from Pristimantis lacrimosus by its call emitted at a lower frequency, and from Pristimantis waoranii for its dorsal coloration with dark markings. Two other species have partially overlapping distributions and resemble the new species, Pristimantis mendax and Pristimantis olivaceus, but they produce advertisement calls with much higher dominant frequencies than the advertisement call of the new species. Furthermore, Pristimantis mendax differs from the new species by lacking a rostral tubercle and by having a sigmoid inner tarsal fold, whereas Pristimantis olivaceus differs by being smaller and by having dorsal skin shagreen with scattered tubercles. The new species has snout-vent length of 21.8–26.9 mm in males (n = 12) and 28.8 mm in a single female. PMID:27408563

  20. Seasonal variations in phytoplankton diversity in the Bui dam area of the Black Volta in Ghana during the pre- and post-impoundment periods.

    PubMed

    Alhassan, Elliot Haruna

    2015-03-01

    Phytoplankton constitutes the primary producers of aquatic ecosystems and represents the food chain base that supports the commercial fisheries of most water bodies. Nowadays, there is lack of information on phytoplankton assemblages of most reservoirs in Africa. To contribute with this knowledge, this study was carried out to determine the density and diversity of seasonal variations of phytoplankton species in the Bui dam area of the Black Volta, during the pre- (2011) and post-impoundment (2012) periods. For this, a three-level stratified random sampling approach was adopted for 22 months. Phytoplankton samples were obtained by towing a 0.5m diameter phytoplankton net (35 microm mesh size and 0.25m2 mouth surface area) from a non-motorized canoe through a distance of about 100 m against the current from downstream to upstream of the river. In 2011, 35 species of phytoplankton belonging to four classes, Bacillariophyceae (7.6%), Chlorophyceae (43%), Cyanophyceae (48.6%) and Euglenophyceae (0.8%) were identified. In the 2012 sampling, 18 species belonging to three classes, Bacillariophyceae (2.2%), Chlorophyceae (26.1%) and Cyanophyceae (71.7%) were observed. A total of 17 species of phytoplankton, including Gyrosigma sp., Surirella sp., Carteria sp., Chlosterium sp., Chlorogonium sp., Coelastrum sp., Cosmarium sp., Volvox sp., Chroococcus sp., Coelosphaerium sp., Rivularia sp. and Spirulina sp., were absent during the late post-impoundment period. Mean monthly total phytoplankton abundance decreased from June (7 384 cells/M3) to August (106 cells/m3) in 2011. In 2012 however, mean total phytoplankton decreased from February (1237 cels/m3) to August (4 cells/m3). The results also showed that variations occurred between seasons among some phytoplankton groups. The dry and pre-wet seasons had significantly (p<0.05) higher mean phytoplankton abundance than the wet season during the 22 months of sampling period. The biotic indices of Shannon-Wiener (HI) were

  1. Cell disruption and lipid extraction for microalgal biorefineries: A review.

    PubMed

    Lee, Soo Youn; Cho, Jun Muk; Chang, Yong Keun; Oh, You-Kwan

    2017-06-12

    The microalgae-based biorefinement process has attracted much attention from academic and industrial researchers attracted to its biofuel, food and nutraceutical applications. In this paper, recent developments in cell-disruption and lipid-extraction methods, focusing on four biotechnologically important microalgal species (namely, Chlamydomonas, Haematococcus, Chlorella, and Nannochloropsis spp.), are reviewed. The structural diversity and rigidity of microalgal cell walls complicate the development of efficient downstream processing methods for cell-disruption and subsequent recovery of intracellular lipid and pigment components. Various mechanical, chemical and biological cell-disruption methods are discussed in detail and compared based on microalgal species and status (wet/dried), scale, energy consumption, efficiency, solvent extraction, and synergistic combinations. The challenges and prospects of the downstream processes for the future development of eco-friendly and economical microalgal biorefineries also are outlined herein. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The GC-Rich Mitochondrial and Plastid Genomes of the Green Alga Coccomyxa Give Insight into the Evolution of Organelle DNA Nucleotide Landscape

    SciTech Connect

    Smith, David Roy; Burki, Fabien; Yamada, Takashi; Grimwood, Jane; Grigoriev, Igor V.; Van Etten, James L.; Keeling, Patrick J.

    2011-05-13

    Most of the available mitochondrial and plastid genome sequences are biased towards adenine and thymine (AT) over guanine and cytosine (GC). Examples of GC-rich organelle DNAs are limited to a small but eclectic list of species, including certain green algae. Here, to gain insight in the evolution of organelle nucleotide landscape, we present the GC-rich mitochondrial and plastid DNAs from the trebouxiophyte green alga Coccomyxa sp. C-169. We compare these sequences with other GC-rich organelle DNAs and argue that the forces biasing them towards G and C are nonadaptive and linked to the metabolic and/or life history features of this species. The Coccomyxa organelle genomes are also used for phylogenetic analyses, which highlight the complexities in trying to resolve the interrelationships among the core chlorophyte green algae, but ultimately favour a sister relationship between the Ulvophyceae and Chlorophyceae, with the Trebouxiophyceae branching at the base of the chlorophyte crown.

  3. Phytoplankton composition of Euphrates River in Al-Hindiya barrage and Kifil City region of Iraq.

    PubMed

    Hassan, Fikrat M; Taylor, William D; Al-Taee, Mayson M S; Al-Fatlawi, Hassan J J

    2010-05-01

    Seasonal variations in phytoplankton abundance and their composition were studied at five stations in the middle region (between Al-Hindiya barrage to Kifil City) of the Euphrates River in Iraq between March, 2004, and February, 2005. A total 151 taxa of phytoplankton were identified, belonging to Bacillariophyceae (98), Chlorophyceae (33), Cyanophyceae (14), Euglenophyceae (2), Xanthophyceae (2), and Dinophyceae (2). The total abundance of phytoplankton cells varied from 136 to 5312 cells l(-1) with maxima in spring and fall. Bacillariophyceae were the most abundant group at all stations. Some species of phytoplankton occurred continuously during the study period (Cyclotella ocellata, C. meneghiana, Cocconeis placentula, Nitzchia spp, Meringosphaera spinosa). The study recorded four species as new records for Iraqi. The phytoplankton was indicative of oligotrophic conditions although it showed some signs of organic pollution near cities.

  4. Spatial and temporal variation of phytoplankton in a tropical eutrophic river.

    PubMed

    Santana, L M; Moraes, M E B; Silva, D M L; Ferragut, C

    2016-04-19

    This study aims to evaluate the environmental factors determining of the changes in phytoplankton structure in spatial (upper, middle and lower course) and seasonal (dry and rainy period) scales in a eutrophic river (Almada River, northeastern Brazil). In the study period, total accumulated rainfall was below of the historic average, resulting in flow reduction, mainly in rainy period. High orthophosphate concentration was found at the sampling sites. Phytoplankton chlorophyll a increased from upstream to downstream. Geitlerinema splendidum (S1) and Chlamydomonas sp. (X2) were the most abundant species in the upper course and several species of diatoms (D), Euglenophyceae (W1, W2) and Chlorophyceae (X1) in the middle and lower course. The functional groups were found to be characteristic of lotic ecosystem, shallow, with low light availability, rich in organic matter and eutrophic environments. We conclude that phytoplankton community structure was sensitive to change of the river flow and nutrient availability in spatial and seasonal scale in a tropical river.

  5. N/sub 2/O evolution by green algae. [Chlorella; Scenedesmus; Coelastrum; Chlorococcum

    SciTech Connect

    Weathers, P.J.

    1984-12-01

    Nitrous oxide (N/sub 2/O) is an intermediate in denitrification and a by-product of both nitrification and dissimilatory nitrogen oxide reduction. The extent of the global source and pool of N/sub 2/O is uncertain and especially controversial in aquatic systems. Recognition of new, widespread biological sources of N/sub 2/O affects current theories of the global N/sub 2/O balance. Evidence is presented here that axenic cultures of Chlorella, Scenedesmus, Coelastrum, and Chlorococcum spp. evolve N/sub 2/O when grown on NO/sub 2//sup -/, showing that the Chlorophyceae are a source of N/sub 2/O in aquatic systems. 18 references, 2 tables.

  6. A short flagella mutant of Dunaliella sallina (Chlorophyta, Cholorophyceae).

    PubMed

    Vismara, Rosa; Verni, Franco; Barsanti, Laura; Evangelista, Valtere; Gualtieri, Paolo

    2004-01-01

    Dunaliella salina (Chlorophyta, Chlorophyceae) is a unicellular wall-less biflagellate alga. In this paper we describe a spontaneous mutant of D. salina, isolated from wild type cultures, which is characterized by very short flagella. The ultrastructure showed the basic 9 + 2 organization of wild-type flagella. Immunofluorescence localization of tubulin in this mutant confirmed the normal construction of the axoneme. Although, the mutant does not swim, still it is able to move and perform photobehavior. As shown by track reconstruction, and rotation movements, observed by means of reflection microscopy, this mutant can move, probably gliding by means of its stumpy flagella. A possible model to explain the mutant motion pattern is discussed.

  7. Chloroplast Phylogenomic Inference of Green Algae Relationships.

    PubMed

    Sun, Linhua; Fang, Ling; Zhang, Zhenhua; Chang, Xin; Penny, David; Zhong, Bojian

    2016-02-05

    The green algal phylum Chlorophyta has six diverse classes, but the phylogenetic relationship of the classes within Chlorophyta remains uncertain. In order to better understand the ancient Chlorophyta evolution, we have applied a site pattern sorting method to study compositional heterogeneity and the model fit in the green algal chloroplast genomic data. We show that the fastest-evolving sites are significantly correlated with among-site compositional heterogeneity, and these sites have a much poorer fit to the evolutionary model. Our phylogenomic analyses suggest that the class Chlorophyceae is a monophyletic group, and the classes Ulvophyceae, Trebouxiophyceae and Prasinophyceae are non-monophyletic groups. Our proposed phylogenetic tree of Chlorophyta will offer new insights to investigate ancient green algae evolution, and our analytical framework will provide a useful approach for evaluating and mitigating the potential errors of phylogenomic inferences.

  8. A comparative hydrobiological study of a few ponds of Barak Valley, Assam and their role as sustainable water resources.

    PubMed

    Bhuiyan, J R; Gupta, S

    2007-10-01

    A hydrobiological study conducted in nine different ponds of a rural area of Barak Valley, Assam, showed that the concentrations of chemical parameters like dissolved oxygen, free carbon dioxide, pH, conductivity alkalinity nitrate, phosphate, calcium, magnesium, copper and zinc are within the permissible levels of drinking water quality standard of WHO and ISI. However iron content was higher in most of the ponds. A clear indirect relationship between iron concentration and euglenoids has been observed. Major phytoplankton taxa present in the ponds are Chlorophyceae, Cyanophyceae, Bacillariophyceae and Euglenophyceae. The study reveals that rural ponds can be a very good source of water for drinking, domestic use and fishery and should be conserved at any cost.

  9. Hydrobiological study of lake Mirik in Darjeeling Himalayas.

    PubMed

    Jha, Prithwiraj; Barat, Sudip

    2003-07-01

    Some hydrobiological features of lake Mirik, situated in the Darjeeling Himalayas were studied during May to October, 2000. Water temperature showed abrupt fluctuations. The pH was generally acidic. Dissolved oxygen increased steadily with increasing rainfall and recorded highest in late August (12.6 mgl(-1)). The gross primary productivity had a highest value of 87.50 mg C m(-3) hr(-1). Chlorophyceae and Cyanophyceae were identified among phytoplanktons. Zooplanktons were represented by Cladocerans and Copepods. The study revealed higher concentration of nutrients at certain pockets of the lake, which points to increasing human influences in the system, and, the water cannot serve as a scarcity alternative for drinking purpose.

  10. The green seaweed Ulva: a model system to study morphogenesis.

    PubMed

    Wichard, Thomas; Charrier, Bénédicte; Mineur, Frédéric; Bothwell, John H; Clerck, Olivier De; Coates, Juliet C

    2015-01-01

    Green macroalgae, mostly represented by the Ulvophyceae, the main multicellular branch of the Chlorophyceae, constitute important primary producers of marine and brackish coastal ecosystems. Ulva or sea lettuce species are some of the most abundant representatives, being ubiquitous in coastal benthic communities around the world. Nonetheless the genus also remains largely understudied. This review highlights Ulva as an exciting novel model organism for studies of algal growth, development and morphogenesis as well as mutualistic interactions. The key reasons that Ulva is potentially such a good model system are: (i) patterns of Ulva development can drive ecologically important events, such as the increasing number of green tides observed worldwide as a result of eutrophication of coastal waters, (ii) Ulva growth is symbiotic, with proper development requiring close association with bacterial epiphytes, (iii) Ulva is extremely developmentally plastic, which can shed light on the transition from simple to complex multicellularity and (iv) Ulva will provide additional information about the evolution of the green lineage.

  11. Algae Polysaccharides' Chemical Characterization and their Role in the Inflammatory Process.

    PubMed

    Florez, Noelia; Gonzalez-Munoz, Maria Jesus; Ribeiro, Daniela; Fernandes, Eduarda; Dominguez, Herminia; Freitas, Marisa

    2017-01-01

    Polysaccharides are abundant components in marine macroalgae with potential applications in different areas such as pharmaceutical, biomedical, cosmetics and nutrition. The current interest in these compounds is due to their known bioactivities, conferred by their antiallergic, neuroprotective, gastroprotective, cardioprotective, cytotoxic, anticoagulant/antithrombotic, antiviral, antilipidemic, antinociceptive, and immunomodulatory properties, making them promising bioactive products and biomaterials. The inflammatory process is a complex event mediated by the immune system that culminates in the neutralization and elimination of the offending insult protecting the host and restoring tissue homeostasis. This review focuses on the extraction procedures and chemical characterization of polysaccharides from different classes of algae (Phaeophyceae, Rhodophyceae and Chlorophyceae) and on the studies on their inflammatory process modulatory effect.

  12. Biodiversity and molecular evolution of microalgae on different epiphytes and substrates.

    PubMed

    MubarakAli, D; Ershath, M I Mohammed; Thajuddin, N

    2012-09-01

    An exploration of the microalgal biodiversity from different epiphytes and substrates of pool water in temple at Tiruchirappalli District was studied. Totally ten epiphytic forms were selected for this investigation. In that, totally 44 species of 30 genera belonging to 3 families of the Chlorophyceae, Cyanophyceae (heterocystous and non-heterocystous) and Bacillariophyceae were identified and recorded. The dominant species in this environment were Cyanobacteria (Chroococcus sp. and Oscillatoria sp., Phormidium sp.), Green algae (Tetradron sp. and Scenedesmus sp.) and Diatom (Fragilaria sp. and Navicula sp.) were documented. The molecular taxonomy of cyanobacteria were also analyzed, in this regards, DNA was extracted; 16S rDNA gene was amplified and sequenced. The evolutionary relationship was found in the epiphytic microalgae by Neighbour-Joining method by construction of phylogenetic tree.

  13. Species-specific isotope tracers to study the accumulation and biotransformation of mixtures of inorganic and methyl mercury by the microalga Chlamydomonas reinhardtii.

    PubMed

    Bravo, Andrea Garcia; Le Faucheur, Séverine; Monperrus, Mathilde; Amouroux, David; Slaveykova, Vera I

    2014-09-01

    The present study demonstrates that species-specific isotope tracing is an useful tool to precisely measure Hg accumulation and transformations capabilities of living organisms at concentrations naturally encountered in the environment. To that end, a phytoplanktonic green alga Chlamydomonas reinhardtii Dangeard (Chlamydomonadales, Chlorophyceae) was exposed to mixtures of (199)-isotopically enriched inorganic mercury ((199)IHg) and of (201)-isotopically enriched monomethylmercury ((201)CH3Hg) at a concentration range between less than 1 pM to 4 nM. Additionally, one exposure concentration of both mercury species was also studied separately to evaluate possible interactive effects. No difference in the intracellular contents was observed for algae exposed to (199)IHg and (201)CH3Hg alone or in their mixture, suggesting similar accumulation capacity for both species at the studied concentrations. Demethylation of (201)CH3Hg was observed at the highest exposure concentrations, whereas no methylation was detected.

  14. SSU rRNA GENE PHYLOGENY OF MORPHOSPECIES AFFILIATED TO THE BIOASSAY ALGA "SELENASTRUM CAPRICORNUTUM" RECOVERED THE POLYPHYLETIC ORIGIN OF CRESCENT-SHAPED CHLOROPHYTA(1).

    PubMed

    Krienitz, Lothar; Bock, Christina; Nozaki, Hisayoshi; Wolf, Matthias

    2011-08-01

    The generic concept of coccoid green algae exhibiting a crescent-shaped morphotype is evaluated using SSU rRNA gene sequence analyses and light and electron microscopical observations. These common chlorophytes evolved polyphyletically in 10 different clades of the Chlorophyceae and three clades of the Trebouxiophyceae. Six clades are assigned to known genera of Selenastraceae: Kirchneriella, Nephrochlamys, Raphidocelis, Rhombocystis, Selenastrum, and Tetranephris. Four other clades, named following their present genus designation as Ankistrodesmus-like I and II and Monoraphidium-like I and II, require further investigation. One crescent-shaped morphotype, which evolved within the Trebouxiophyceae, is designated as Neocystis mucosa sp. nov. The other two lineages containing trebouxiophycean algae with this morphotype are the Elliptochloris and the Watanabea clades. The taxonomic placement of the widely used bioassay strain "Selenastrum capricornutum" NIVA-CHL 1 in the genus Raphidocelis (species name Raphidocelis subcapitata) is indicated by molecular data. © 2011 Phycological Society of America.

  15. Algal growth effects on arsenic transport in a mining-impacted stream

    SciTech Connect

    Kuwabara, J.S.; Chang, C.C.Y.; Pasilis, S.P. )

    1987-06-01

    Increased periphyton abundance in Whitewood Creek, South Dakota during the summer months suggests that chemical interactions involving arsenic (As) between biota and the overlying waters may significantly affect As transport and distribution in this mining-impacted stream. Arsenic transport parameters (e.g., uptake rate constants, standing crop and accumulation factors) for algae collected in the creek from upstream of a mine discharge through a 25 mile impacted reach are being determined. Cultures of Stichococcus spp Nageli (chlorophyceae) were isolated from four sites along a dissolved As concentration gradient within the study reach and then maintained at ambient dissolved As concentrations. Arsenic uptake and release rate constants for these isolates as a function of dissolved arsenate and orthophosphate have been determined. All isolates appeared to have some As exculsion mechanism involving an interaction with dissolved phosphate. Results from transport parameter measurements indicate that periphyton represent a significant As pool interacting with the surrounding solution and solid phases.

  16. Seasonal phytoplanktonic diversity of Kitham lake, Agra.

    PubMed

    Tiwari, Ashesh; Chauhan, S V S

    2006-01-01

    Two years (Jan. 2000 - Dec. 2001) data on the seasonal studies of phytoplanktonic diversity of Kitham lake (Sur Sarovar) Agra revealed the presence of 73 algal species. A limited number of these were recorded throughout the year, while others were distributed in different seasons mainly in winter and summer seasons. During winters, Chlorophyceae was the most dominant group followed by Bacillariophyceae. On the other hand, Cyanophyceae and Euglenophyceae were the most dominant during summers. Certain species e.g. Pandorina morum, Pediastrum tetras, Gonium sp., Chlorella vulgaris, Scendesmus quadricauda, Oedogonium cardiocum, Synedra ulna, Oscillatoria agardhii and Euglena gracillis were recorded throughout the year. Chlorella, Stigeoclonium, Pandorina, Micratinium, Oscillatoria, Anacystis, Nitzschia and Cymbella were found to be good indicators of water pollution.

  17. Chloroplast Phylogenomic Inference of Green Algae Relationships

    PubMed Central

    Sun, Linhua; Fang, Ling; Zhang, Zhenhua; Chang, Xin; Penny, David; Zhong, Bojian

    2016-01-01

    The green algal phylum Chlorophyta has six diverse classes, but the phylogenetic relationship of the classes within Chlorophyta remains uncertain. In order to better understand the ancient Chlorophyta evolution, we have applied a site pattern sorting method to study compositional heterogeneity and the model fit in the green algal chloroplast genomic data. We show that the fastest-evolving sites are significantly correlated with among-site compositional heterogeneity, and these sites have a much poorer fit to the evolutionary model. Our phylogenomic analyses suggest that the class Chlorophyceae is a monophyletic group, and the classes Ulvophyceae, Trebouxiophyceae and Prasinophyceae are non-monophyletic groups. Our proposed phylogenetic tree of Chlorophyta will offer new insights to investigate ancient green algae evolution, and our analytical framework will provide a useful approach for evaluating and mitigating the potential errors of phylogenomic inferences. PMID:26846729

  18. An ecologic and taxonomic study on phytoplankton of a shallow lake, Turkey.

    PubMed

    Tas, Beyhan; Gonulol, Arif

    2007-04-01

    The middle Black sea region has quite large wetlands, including lakes, rivers, ponds, marshs and large reservoirs. Lake Cernek is one of the most valuable wetlands in Kizilirmak Delta. The lake and its environment have a high biodiversity due to species richness and natural habitats. Therefore, it has been recognized as a Ramsar site. The phytoplankton of lake Cemek consisted of 104 taxa belonging to Cyanobacteria, Bacillariophyta, Chlorophyta, Cryptophyta, Dinophyta, Euglenophyta and Xanthophyta divisions. Chlorophyta (46%) and Bacillariophyta (23%) members were dominant species. These were followed by Cyanobacteria (16%) and Euglenophyta (11%) members. Chlorella, Monoraphidium, Oocystis, Pediastrum and Scenedesmus from Chlorophyceae and also Anabaena, Chroococcus and Microcystis species from Cyanophyceae sometimes made water blooms. Blue green algae constituted algal communities in the surface of the lake in summer months. Algal community and its important species were grouped in terms of bray curtis similarity index, by taking into consideration the phytoplankton dynamics and months.

  19. α-Carotene and its derivatives have a sole chirality in phototrophic organisms?

    PubMed

    Takaichi, Shinichi; Murakami, Akio; Mochimaru, Mari; Yokoyama, Akiko

    2012-01-01

    Carotenoids in eukaryotic phototrophic organisms can be classified into two groups; β-carotene and its derivatives, and α-carotene and its derivatives. We re-examined distribution of α-carotene and its derivatives among various taxa of aquatic algae (17 classes) and land plants. α-carotene and its derivatives were found from Rhodophyceae (macrophytic type), Cryptophyceae, Euglenophyceae, Chlorarachniophyceae, Prasinophyceae, Chlorophyceae, Ulvophyceae, Charophyceae, and land plants, while they could not be detected from Glaucophyceae, Rhodophyceae (unicellular type), Chryosophyceae, Raphidophyceae, Bacillariophyceae, Phaeophyceae, Xanthophyceae, Eustigmatophyceae, Haptophyceae, and Dinophyceae. We also analyzed the chirality of α-carotene and/or its derivatives, such as lutein and siphonaxanthin, and found all of them had only (6'R)-type, not (6'S)-type.

  20. Studies on spatio-temporal dynamics of phytoplankton in El-Umum drain in west of Alexandria, Egypt.

    PubMed

    Hussein, Nabila R; Gharib, Samiha M

    2012-01-01

    Phytoplankton was assessed quantitatively and qualitatively in regard to their abundance in the northern part of El-Umum drain, west of Alexandria at four stations to study the spatial, temporal, dominance and abundance of the phytoplankton community. The samples were collected monthly from April 2003 to April 2004. Atotal of 152 phytoplankton taxa were identified belonging to Bacillariophyceae (60), Chlorophyceae (46), Cyanophyceae (20), Euglenophyceae (17) and Dinophyceae (9). A limited number of these were recorded throughout the year, and showed an indication of organic pollution. The total densities (333.8x10(3) units l(-1)) were mainly a reflection of the trends in counts of Bacillariophyceae and Chlorophyceae (138.1 x 10(3) and 131.6 x 10(3) units l(-1), respectively). Monthly differences in the quantitative (18 x 10(3) to 1645 x 10(3) units l(-1)) and qualitative composition (41 to 113 taxa) of the phytoplankton communities in the different stations were marked, with recurrent high abundance in spring (910.4 x 10(3) units l(-1)), whereas lowest densities occurred in autumn (99.7x10(3) units l(-1)). Cyanophyceae was most abundant in July (67.5 x 10(3) units l(-1)), whereas Euglenophyceae in December (32.0x10(3) units l(-1)). Species diversity (H') gave a signal of the area is light to moderate polluted. The present study emphasized the need to use phytoplankton community as index of water quality.

  1. Lineage-specific fragmentation and nuclear relocation of the mitochondrial cox2 gene in chlorophycean green algae (Chlorophyta).

    PubMed

    Rodríguez-Salinas, Elizabeth; Riveros-Rosas, Héctor; Li, Zhongkui; Fucíková, Karolina; Brand, Jerry J; Lewis, Louise A; González-Halphen, Diego

    2012-07-01

    In most eukaryotes the subunit 2 of cytochrome c oxidase (COX2) is encoded in intact mitochondrial genes. Some green algae, however, exhibit split cox2 genes (cox2a and cox2b) encoding two polypeptides (COX2A and COX2B) that form a heterodimeric COX2 subunit. Here, we analyzed the distribution of intact and split cox2 gene sequences in 39 phylogenetically diverse green algae in phylum Chlorophyta obtained from databases (28 sequences from 22 taxa) and from new cox2 data generated in this work (23 sequences from 18 taxa). Our results support previous observations based on a smaller number of taxa, indicating that algae in classes Prasinophyceae, Ulvophyceae, and Trebouxiophyceae contain orthodox, intact mitochondrial cox2 genes. In contrast, all of the algae in Chlorophyceae that we examined exhibited split cox2 genes, and could be separated into two groups: one that has a mitochondrion-localized cox2a gene and a nucleus-localized cox2b gene ("Scenedesmus-like"), and another that has both cox2a and cox2b genes in the nucleus ("Chlamydomonas-like"). The location of the split cox2a and cox2b genes was inferred using five different criteria: differences in amino acid sequences, codon usage (mitochondrial vs. nuclear), codon preference (third position frequencies), presence of nucleotide sequences encoding mitochondrial targeting sequences and presence of spliceosomal introns. Distinct green algae could be grouped according to the form of cox2 gene they contain: intact or fragmented, mitochondrion- or nucleus-localized, and intron-containing or intron-less. We present a model describing the events that led to mitochondrial cox2 gene fragmentation and the independent and sequential migration of cox2a and cox2b genes to the nucleus in chlorophycean green algae. We also suggest that the distribution of the different forms of the cox2 gene provides important insights into the phylogenetic relationships among major groups of Chlorophyceae.

  2. Seasonal dynamics of phytoplankton community in a tropical wetland.

    PubMed

    Bhat, Najeeb Ahmad; Wanganeo, Ashwani; Raina, Rajni

    2015-01-01

    Phytoplankton species composition and seasonal changes were investigated in the Bhoj wetland Bhopal. Taxonomic composition, diversity, and abundance of phytoplankton were studied at nine stations from March 2008 to February 2010, in relation to various physico-chemical factors. Total phytoplankton species composition in the Bhoj wetland was represented by 360 species. Among phytoplankton, diversity belonged to seven groups. Chlorophyceae was the dominant group (48%) followed by Bacillariophyceae (26%), Cyanophyceae (15%), and Euglenophyceae (9%), while Pyrophyceae, Chrysophyceae, and Xanthophyceae contributed 2% of the population. Phytoplankton on the basis of seasonal studies recorded 1651 units l(-1) during summer season which was contributed mainly by Chlorophyceae (39.3%), with Spirogyra sp. (14.2%) and Closteriopsis sp. (9.1%) contributing maximum to the total group in the first year, while during the second year of summer period, a total of 2095 units l(-1) was recorded which was contributed mainly by group Pyrophyceae (51%) with the main dominant species represented by Ceratium hirundinella (98.46%). The highest Shannon-Wiener diversity index (H') value (4.27) was recorded. Simpson values are approaching 1, signifying that sites have high relative diversity due to its supporting surrounding components. The trend of variation in evenness values was more or less the same as Shannon diversity index. Thus, the highest diversity indices recoded at all the stations in the present study justify the diverse nature of species inhabiting the different ecological niches in the ecosystem. The very high phosphate and nitrate concentrations in the wetland are indicators of pollution which may be due to the discharge of agricultural and sewage wastes enriched with nutrients as well as the human activities there. Our recommendation is to avoid as far as possible the discharge of sewage and agriculture wastes into the Bhoj wetland. The effects of various physicochemical

  3. ITS2 data corroborate a monophyletic chlorophycean DO-group (Sphaeropleales)

    PubMed Central

    2008-01-01

    Background Within Chlorophyceae the ITS2 secondary structure shows an unbranched helix I, except for the 'Hydrodictyon' and the 'Scenedesmus' clade having a ramified first helix. The latter two are classified within the Sphaeropleales, characterised by directly opposed basal bodies in their flagellar apparatuses (DO-group). Previous studies could not resolve the taxonomic position of the 'Sphaeroplea' clade within the Chlorophyceae without ambiguity and two pivotal questions remain open: (1) Is the DO-group monophyletic and (2) is a branched helix I an apomorphic feature of the DO-group? In the present study we analysed the secondary structure of three newly obtained ITS2 sequences classified within the 'Sphaeroplea' clade and resolved sphaeroplealean relationships by applying different phylogenetic approaches based on a combined sequence-structure alignment. Results The newly obtained ITS2 sequences of Ankyra judayi, Atractomorpha porcata and Sphaeroplea annulina of the 'Sphaeroplea' clade do not show any branching in the secondary structure of their helix I. All applied phylogenetic methods highly support the 'Sphaeroplea' clade as a sister group to the 'core Sphaeropleales'. Thus, the DO-group is monophyletic. Furthermore, based on characteristics in the sequence-structure alignment one is able to distinguish distinct lineages within the green algae. Conclusion In green algae, a branched helix I in the secondary structure of the ITS2 evolves past the 'Sphaeroplea' clade. A branched helix I is an apomorph characteristic within the monophyletic DO-group. Our results corroborate the fundamental relevance of including the secondary structure in sequence analysis and phylogenetics. PMID:18655698

  4. Genome sequences of six Phytophthora species associated with forests in New Zealand

    PubMed Central

    Studholme, D.J.; McDougal, R.L.; Sambles, C.; Hansen, E.; Hardy, G.; Grant, M.; Ganley, R.J.; Williams, N.M.

    2015-01-01

    In New Zealand there has been a long association of Phytophthora diseases in forests, nurseries, remnant plantings and horticultural crops. However, new Phytophthora diseases of trees have recently emerged. Genome sequencing has been performed for 12 Phytophthora isolates, from six species: Phytophthora pluvialis, Phytophthora kernoviae, Phytophthora cinnamomi, Phytophthora agathidicida, Phytophthora multivora and Phytophthora taxon Totara. These sequences will enable comparative analyses to identify potential virulence strategies and ultimately facilitate better control strategies. This Whole Genome Shotgun data have been deposited in DDBJ/ENA/GenBank under the accession numbers LGTT00000000, LGTU00000000, JPWV00000000, JPWU00000000, LGSK00000000, LGSJ00000000, LGTR00000000, LGTS00000000, LGSM00000000, LGSL00000000, LGSO00000000, and LGSN00000000. PMID:26981359

  5. Genome sequences of six Phytophthora species associated with forests in New Zealand.

    PubMed

    Studholme, D J; McDougal, R L; Sambles, C; Hansen, E; Hardy, G; Grant, M; Ganley, R J; Williams, N M

    2016-03-01

    In New Zealand there has been a long association of Phytophthora diseases in forests, nurseries, remnant plantings and horticultural crops. However, new Phytophthora diseases of trees have recently emerged. Genome sequencing has been performed for 12 Phytophthora isolates, from six species: Phytophthora pluvialis, Phytophthora kernoviae, Phytophthora cinnamomi, Phytophthora agathidicida, Phytophthora multivora and Phytophthora taxon Totara. These sequences will enable comparative analyses to identify potential virulence strategies and ultimately facilitate better control strategies. This Whole Genome Shotgun data have been deposited in DDBJ/ENA/GenBank under the accession numbers LGTT00000000, LGTU00000000, JPWV00000000, JPWU00000000, LGSK00000000, LGSJ00000000, LGTR00000000, LGTS00000000, LGSM00000000, LGSL00000000, LGSO00000000, and LGSN00000000.

  6. Sediment ingestion of two sympatric shorebird species

    USGS Publications Warehouse

    Hui, C.A.; Beyer, W.N.

    1998-01-01

    Black-bellied Plovers (Pluvialis squatarola) have short bills and primarily peck while foraging whereas Willets (Catoptrophorus semipalmatus) have long bills and primarily probe with bills open in sediments. Intestinal digesta were collected from these species at sympatric overwintering sites in southern California near San Diego to relate sediment ingestion to bill length and feeding behavior. Plover digesta contained an estimated 29% sediment, and Willet digesta an estimated 3% sediment. Techniques based on acid insoluble ash and on the elemental markers of Al, Fe, and Ti in digesta provided similar results. High Ca concentrations in Willet digesta and our observations suggested that the willets in our sample fed primarily on molluscs and crustaceans. Sediment ingestion may be species specific, not necessarily linked to bill length or probing behaviors, and may greatly affect a bird?s exposure to environmental contaminants in sediment.

  7. Analysis of the feeding sites for some horse flies (Diptera, Tabanidae) on a human in Croatia.

    PubMed

    Krcmar, Stjepan; Marić, Svjetlana

    2006-12-01

    The landing patterns of horse flies on the human body were observed in Croatia. A total of 386 horse flies belonging to 22 species were sampled. The five most commonly collected species were used in the analysis. The stochastic linear connection is tight among the landings of the species Tabanus bromius, Tabanus maculicornis, Tabanus tergestinus, and Philipomyia graeca on the human body regions (matrix R). The preferred feeding area for these four species was the lower leg, whereas for the species Haematopota pluvialis it was the head and neck. Of the total number of horse flies that landed 44.81% were on the lower leg. Only 0.26% landed on the forearm. Chi-square analysis indicated non random landing patterns on human by these horse flies.

  8. Predicting breeding shorebird distributions on the Arctic Coastal Plain of Alaska

    USGS Publications Warehouse

    Saalfeld, Sarah T.; Lanctot, Richard B.; Brown, Stephen C.; Saalfeld, David T.; Johnson, James A.; Andres, Brad A.; Bart, Jonathan R.

    2013-01-01

    The Arctic Coastal Plain (ACP) of Alaska is an important region for millions of migrating and nesting shorebirds. However, this region is threatened by climate change and increased human development (e.g., oil and gas production) that have the potential to greatly impact shorebird populations and breeding habitat in the near future. Because historic data on shorebird distributions in the ACP are very coarse and incomplete, we sought to develop detailed, contemporary distribution maps so that the potential impacts of climate-mediated changes and development could be ascertained. To do this, we developed and mapped habitat suitability indices for eight species of shorebirds (Black-bellied Plover [Pluvialis squatarola], American Golden-Plover [Pluvialis dominica], Semipalmated Sandpiper [Calidris pusilla], Pectoral Sandpiper [Calidris melanotos], Dunlin [Calidris alpina], Long-billed Dowitcher [Limnodromus scolopaceus], Red-necked Phalarope [Phalaropus lobatus], and Red Phalarope [Phalaropus fulicarius]) that commonly breed within the ACP of Alaska. These habitat suitability models were based on 767 plots surveyed during nine years between 1998 and 2008 (surveys were not conducted in 2003 and 2005), using single-visit rapid area searches during territory establishment and incubation (8 June, 1 July). Species specific habitat suitability indices were developed and mapped using presence-only modeling techniques (partitioned Mahalanobis distance) and landscape environmental variables. For most species, habitat suitability was greater at lower elevations (i.e., near the coast and river deltas) and lower within upland habitats. Accuracy of models was high for all species, ranging from 65 -98%. Our models predicted that the largest fraction of suitable habitat for the majority of species occurred within the National Petroleum Reserve-Alaska, with highly suitable habitat also occurring within coastal areas of the Arctic National Wildlife Refuge west to Prudhoe Bay.

  9. Proterozoic microfossils revealing the time of algal divergences

    NASA Astrophysics Data System (ADS)

    Moczydlowska-Vidal, Malgorzata

    2010-05-01

    fossils more ubiquitously and without mineralization. Microalgae radiated quickly in the Cambrian and Ordovician; however, several morphotypes with features related to the reproductive cycle occur in the Proterozoic, although they are not always recognized as such. The assignment of Proterozoic unicellular microfossils with resistant cell walls to specific eukaryotic groups is tentative. However, we argue that the new interpretations of their functional morphology, combined with cell wall ultrastructure and biochemistry, allow their assignment to microalgal classes. Microfossils with advanced ornamentation and ontogenetically formed excystment structures or endocysts, which prove that they are cysts in a complex life cycle with sexual reproduction, are related to the basal lineage of the Chlorophytes and the class Chlorophyceae. A cell wall ultrastructure with a TLS supports the affinity of some spheroidal taxa to the Chlorophytes. The phylogeny of the Chlorophytes shows a sequence of branching nodes from a stem-group of the Viridiplantae that leads to the classes Prasinophyceae and Chlorophyceae, and then the Ulvophyceae. Based on a modern interpretation of the record, the timing of these nodes is deduced to be prior to c. 1650 Ma for the Prasinophyceae, c. 1450 Ma for the Chlorophyceae, and c. 950 Ma for the Ulvophyceae. The origin of the Chlorophytes, and in general the Viridiplantae, predates 1.8 Ga. These ages, based on microfossils, are earlier than the estimates based on molecular clocks.

  10. The emergence of a new chlorophytan system, and Dr. Kornmann's contribution thereto

    NASA Astrophysics Data System (ADS)

    van den Hoek, C.; Stam, W. T.; Olsen, J. L.

    1988-09-01

    In traditional chlorophytan systems the organizational level was the primary character for the distinction of main groups (classes and orders). For instance, in Fott (1971), the flagellate level corresponds with the Volvocales, the coccoid level with the Chlorococcales, the filamentous level with the Ulotrichales, the siphonocladous level with the Siphonocladales, and the siphonous level with the Bryopsidales. The new system presented here is an elaboration and emendation of recently proposed taxonomies and their underlying phylogenetic hypotheses, and it is mainly based on ultrastructural features which have become available over the last 15 years. The following criteria are used for the distinction of classes and orders: (1) architecture of the flagellate cell (flagellate cells are considered as the depositories of primitive characters); (2) type of mitosis-cytokinesis; (3) place of meiosis in the life history and, consequently, the sexual life history type; (4) organizational level and thallus architecture; (5) habitat type (marine versus feshwater and terrestrial); (6) chloroplast type. The following classes are presented: Prasinophyceae, Chlamydophyceae, Ulvophyceae (orders Codiolales, Ulvales, Cladophorales, Bryopsidales, Dasycladales), Pleurastrophyceae (?), Chlorophyceae s.s. (orders Cylindrocapsales, Oedogoniales, Chaetophorales), Zygnematophyceae, Trentepohliophyceae, Charophyceae (orders Klebsormidiales, Coleochaetales, Charales). The new system no longer reflects the traditional hypothesis of a stepwise evolutionary progression of organizational levels in which the flagellate level represents the most primitive lineage, the coccoid and sarcinoid levels lineages of intermediate derivation, and the filamentous, siphonocladous and siphonous levels the most derived lineages. Instead, it is now hypothesized that these levels have arisen over and over again in different chlorophytan lineages which are primarily characterized by their type of flagellate cell

  11. Brood amalgamation in the Bristle-thighed Curlew Numenius tahitiensis: process and function

    USGS Publications Warehouse

    Lanctot, Richard B.; Gill, R.E.; Tibbitts, T.L.; Handel, C.M.

    1995-01-01

    Alloparental care in birds generally involves nonbreeding adults that help at nests or breeding adults that help raise young in communal nests. A less often reported form involves the amalgamation of broods, where one or more adults care for young that are not their own. We observed this phenomenon among Bristle-thighed Curlew Numenius tahitiensis broods in western Alaska during 1990–1992. Amalgamation of broods generally involved the formation of temporary and extended associations. Temporary associations were formed by the incidental convergence of broods soon after they left their nests. During this period, parents defended distinct brood-rearing areas, were antagonistic to conspecifics and remained together for less than 3 days. Extended associations formed when chicks were 1–2 weeks old. Here, parents and their broods occupied distinct, but adjacent, brood-rearing areas and moved around as a unit. Whether a brood participated in either temporary or extended associations or remained solitary appeared to depend on brood density in the immediate area and on hatching date. When chicks were 3–4 weeks old, aggregations of up to ten broods formed wherein young mixed and parents defended a common brood-rearing area. All broods (n = 48) that survived to fledging joined such aggregations. Alloparental care involved only antipredator defence and was not associated with activities such as feeding and brooding. Most female parents abandoned their broods shortly after the young could fly and when aggregations were forming. The female parent of a pair always deserted its young before or on the same day as the male parent and, in every aggregation, one or two males continued to tend young for about 5 days longer than other male parents. In most cases, adults deserted the young 2–6 days before the young departed the area when about 38 days old. Bristle-thighed Curlews also formed temporary associations with American and Pacific Golden Plover Pluvialis dominica and

  12. Integration of algae cultivation as biodiesel production feedstock with municipal wastewater treatment: strains screening and significance evaluation of environmental factors.

    PubMed

    Li, Yecong; Zhou, Wenguang; Hu, Bing; Min, Min; Chen, Paul; Ruan, Roger R

    2011-12-01

    The objectives of this study are to find the robust strains for the centrate cultivation system and to evaluate the effect of environmental factors including light intensity, light-dark cycle, and exogenous CO2 concentration on biomass accumulation, wastewater nutrient removal and biodiesel production. The results showed that all 14 algae strains from the genus of Chlorella, Haematococcus, Scenedesmus, Chlamydomonas, and Chloroccum were able to grow on centrate. The highest net biomass accumulation (2.01 g/L) was observed with Chlorella kessleri followed by Chlorella protothecoides (1.31 g/L), and both of them were proved to be capable of mixotrophic growth when cultivated on centrate. Environmental factors had significant effect on algal biomass accumulation, wastewater nutrients removal and biodiesel production. Higher light intensity and exogenous CO2 concentration with longer lighting period promote biomass accumulation, biodiesel production, as well as the removal of chemical oxygen demand and nitrogen, while, lower exogenous CO2 concentration promotes phosphorus removal. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Dietary Carotenoids Regulate Astaxanthin Content of Copepods and Modulate Their Susceptibility to UV Light and Copper Toxicity

    PubMed Central

    Caramujo, Maria-José; de Carvalho, Carla C. C. R.; Silva, Soraya J.; Carman, Kevin R.

    2012-01-01

    High irradiation and the presence of xenobiotics favor the formation of reactive oxygen species in marine environments. Organisms have developed antioxidant defenses, including the accumulation of carotenoids that must be obtained from the diet. Astaxanthin is the main carotenoid in marine crustaceans where, among other functions, it scavenges free radicals thus protecting cell compounds against oxidation. Four diets with different carotenoid composition were used to culture the meiobenthic copepod Amphiascoides atopus to assess how its astaxanthin content modulates the response to prooxidant stressors. A. atopus had the highest astaxanthin content when the carotenoid was supplied as astaxanthin esters (i.e., Haematococcus meal). Exposure to short wavelength UV light elicited a 77% to 92% decrease of the astaxanthin content of the copepod depending on the culture diet. The LC50 values of A. atopus exposed to copper were directly related to the initial astaxanthin content. The accumulation of carotenoids may ascribe competitive advantages to certain species in areas subjected to pollution events by attenuating the detrimental effects of metals on survival, and possibly development and fecundity. Conversely, the loss of certain dietary items rich in carotenoids may be responsible for the amplification of the effects of metal exposure in consumers. PMID:22822352

  14. Astaxanthin supplementation does not attenuate muscle injury following eccentric exercise in resistance-trained men.

    PubMed

    Bloomer, Richard J; Fry, Andrew; Schilling, Brian; Chiu, Loren; Hori, Naruhiro; Weiss, Lawrence

    2005-08-01

    This investigation was designed to determine the effects of astaxanthin on markers of skeletal muscle injury. Twenty resistance trained men (mean +/- standard error of the mean : age , 25.1 +/- 1.6 y; height, 1.79 +/- 0.02 m; weight, 86.8 +/- 4.4 kg) were assigned to either a placebo (1732 mg safflower oil, n =10) or astaxanthin (BioAstin; 1732 mg safflower oil; haematococcus algae extract [contains 4 mg astaxanthin and 480 mg lutein]n = 10). Subjects consumed their assigned treatment for 3 wk prior to eccentric exercise (10 sets of 10 repetitions at 85% of one repetition maximum) and through 96 h post-exercise. Muscle soreness, creatine kinase (CK), and muscle performance was measured before and through 96 h post-exercise. A similar response was observed for both treatment groups for all dependent variables, indicating that in resistance trained men, astaxanthin supplementation does not favorably affect indirect markers of skeletal muscle injury following eccentric loading.

  15. Microalgal lipid droplets: composition, diversity, biogenesis and functions.

    PubMed

    Goold, Hugh; Beisson, Fred; Peltier, Gilles; Li-Beisson, Yonghua

    2015-04-01

    Lipid droplet is the major site of neutral lipid storage in eukaryotic cells, and increasing evidence show its involvement in numerous cellular processes such as lipid homeostasis, signaling, trafficking and inter-organelle communications. Although the biogenesis, structure, and functions of lipid droplets have been well documented for seeds of vascular plants, mammalian adipose tissues, insects and yeasts, relative little is known about lipid droplets in microalgae. Over the past 5 years, the growing interest of microalgae as a platform for biofuel, green chemicals or value-added polyunsaturated fatty acid production has brought algal lipid droplets into spotlight. Studies conducted on the green microalga Chlamydomonas reinhardtii and other model microalgae such as Haematococcus and Nannochloropsis species have led to the identification of proteins associated with lipid droplets, which include putative structural proteins different from plant oleosins and animal perilipins, as well as candidate proteins for lipid biosynthesis, mobilization, trafficking and homeostasis. Biochemical and microscopy studies have also started to shed light on the role of chloroplasts in the biogenesis of lipid droplets in Chlamydomonas.

  16. Massively parallel sequencing-based survey of eukaryotic community structures in Hiroshima Bay and Ishigaki Island.

    PubMed

    Nagai, Satoshi; Hida, Kohsuke; Urusizaki, Shingo; Takano, Yoshihito; Hongo, Yuki; Kameda, Takahiko; Abe, Kazuo

    2016-02-01

    In this study, we compared the eukaryote biodiversity between Hiroshima Bay and Ishigaki Island in Japanese coastal waters by using the massively parallel sequencing (MPS)-based technique to collect preliminary data. The relative abundance of Alveolata was highest in both localities, and the second highest groups were Stramenopiles, Opisthokonta, or Hacrobia, which varied depending on the samples considered. For microalgal phyla, the relative abundance of operational taxonomic units (OTUs) and the number of MPS were highest for Dinophyceae in both localities, followed by Bacillariophyceae in Hiroshima Bay, and by Bacillariophyceae or Chlorophyceae in Ishigaki Island. The number of detected OTUs in Hiroshima Bay and Ishigaki Island was 645 and 791, respectively, and 15.3% and 12.5% of the OTUs were common between the two localities. In the non-metric multidimensional scaling analysis, the samples from the two localities were plotted in different positions. In the dendrogram developed using similarity indices, the samples were clustered into different nodes based on localities with high multiscale bootstrap values, reflecting geographic differences in biodiversity. Thus, we succeeded in demonstrating biodiversity differences between the two localities, although the read numbers of the MPSs were not high enough. The corresponding analysis showed a clear seasonal change in the biodiversity of Hiroshima Bay but it was not clear in Ishigaki Island. Thus, the MPS-based technique shows a great advantage of high performance by detecting several hundreds of OTUs from a single sample, strongly suggesting the effectiveness to apply this technique to routine monitoring programs.

  17. Strategies to enhance the production of photosynthetic pigments and lipids in chlorophycae species.

    PubMed

    Benavente-Valdés, Juan Roberto; Aguilar, Cristóbal; Contreras-Esquivel, Juan Carlos; Méndez-Zavala, Alejandro; Montañez, Julio

    2016-06-01

    Microalgae are a major natural source for a vast array of valuable compounds as lipids, proteins, carbohydrates, pigments among others. Despite many applications, only a few species of microalgae are cultured commercially because of poorly developed of cultivation process. Nowadays some strategies of culture have been used for enhancing biomass and value compounds yield. The most strategies applied to microalgae are classified into two groups: nutrimental and physical. The nutrimental are considered as change in media composition as nitrogen and phosphorous limitation and changes in carbon source, while physical are described as manipulation in operational conditions and external factors such as application of high-light intensities, medium salinity and electromagnetic fields. The exposition to electromagnetic field is a promising technique that can improve the pigments and biomass yield in microalgae culture. Therefore, is important to describe the advantages and applications of the overall process. The aim of this review was to describe the main culture strategies used to improve the photosynthetic and lipids content in chlorophyceae species.

  18. Phytoplankton biodiversity changes in a shallow tropical reservoir during the hypertrophication process.

    PubMed

    Crossetti, L O; Bicudo, D C; Bicudo, C E M; Bini, L M

    2008-11-01

    Study aimed at evaluating phytoplankton biodiversity changes in a shallow tropical reservoir during its hypertrophication process. Samplings were carried out monthly during 8 consecutive years (1997-2004) in 5 depths. Conspicuous limnological changes in the reservoir derived from the presence and/or removal of the water hyacinth, characterized 3 different phases. Over the time series, reservoir changed from a typical polymictic eutrophic system to hypertrophic one, leading to a reduction of approximately 70 species (average 37%). Chlorophyceae accounted for the highest species richness (46%) among all algal classes and strictly followed total species richness variation. Internal feedback mechanisms intensification over phase III clearly promoted the sharp decrease in biodiversity. Highest decreases, mainly during springs, occurred simultaneously to the highest Cyanobacteria blooms. Increased turbidity due to heavy phytoplankton blooms suppressed all other algal groups, so that at the end of the present study even Cyanobacteria species richness decreased. Total dissolved phosphorous was included in most of the best selected models used to analyze the temporal patterns in species richness loss. Present data show that biodiversity loss following trophic change was not a single dimension of a single factor but, rather, a template of factors (e.g. light, stability) co-varying in consequence of the larger levels of biomass supported in the reservoir.

  19. Response of phytoplankton to an experimental fish culture in net cages in a subtropical reservoir.

    PubMed

    Bartozek, E C R; Bueno, N C; Feiden, A; Rodrigues, L C

    2016-01-01

    This study aimed to evaluate nutrients concentration and spatial-temporal changes in phytoplankton biovolume during an experimental fish culture in net cages in a lateral arm of Salto Caxias reservoir, Brazil. Two sampling stations were placed in the affected lateral arm and other two in a cageless lateral arm. Neither abiotic variables nor phytoplankton biovolume presented significant differences between the treatments. Only temporal changes were confirmed by the analysis performed. Both lateral arms were classified as oligotrophic, reflecting low influence of the net cages. Phytoplankton growth seems to be limited by nitrogen. Biovolume values were, in general, low and five major functional groups were recognized (E, F, G, K and P). In summer higher biovolume values were observed and representatives of Chlorophyceae and Cyanobacteria belonging to the functional groups F and K, respectively, were the most important. In winter phytoplankton was mainly composed by Bacillariophyceae taxa from P group. G group was also restricted to winter and E group occurred in winter and summer. The variations recorded in phytoplankton structure appear to have been mainly influenced by seasonal changes in temperature, precipitation and nutrients availability. The effects of net cages on the abiotic variables and phytoplankton biovolume appear to have been small, probably due to the small number of net cages employed and the system dilution capacity. However, a permanent monitoring of phytoplankton is recommended, since this environment has a carrying capacity, from which the trophic state may increase.

  20. The role of a cascade of reservoirs and seasonal variation in the phytoplankton structure in a tropical river.

    PubMed

    Moura, A N; Severiano, J S; Tavares, N K A; Dantas, E W

    2013-05-01

    This study aims to analyse the influence of a cascade of reservoirs on the density, richness and functional groups of phytoplankton in the Contas River, a tropical river of Brazil. This river has two dams along its course, forming the Pedra and Funil reservoirs. Samples were collected over three consecutive years (Dec., 2007 to Dec., 2010) at 28 sampling stations along the river. We identified 198 species and the stretches downstream from the reservoirs showed greater richness. Chlorophyceae, followed by Bacillariophyceae and Cyanophyceae were the dominant groups and highest density was recorded during the rainy season. Overall, a longitudinal pattern in algal densities was found for both seasons, with the lowest values recorded in sections of the Pedra and Funil reservoirs and the highest densities in the downstream sections. Nine functional groups were identified (C, F, J, MP, S1, Sn, Td, Y, Ws); of these, F and J grouped the species with the highest relative abundance during the dry season, while the S1 group, represented by the cyanobacterium Planktothrix agardhii, was dominant in the rainy season. The present study showed a high longitudinal variation in the phytoplankton richness and density, attributed to the hydrological change between the lotic and lentic stretches. Furthermore, the effects of the cascade of reservoirs on phytoplankton, such as reduced density, increased richness and changes in algal associations, were strongly influenced by habitat heterogeneity found in this environment, as well as the rainfall in the region.

  1. Phytoplankton succession in a tropical freshwater lake, Bhoj Wetland (Bhopal, India): spatial and temporal perspective.

    PubMed

    Ahmed, Ayaz; Wanganeo, Ashwani

    2015-04-01

    Bhoj Wetland is tropical freshwater system in central India "Bhopal" serving the citizens as one of the major source of water since its inception. Understanding the process of phytoplankton variation can be particularly useful in water quality improvement and management decision. In this study, phytoplankton taxonomic composition, temporal and spatial distribution, and diversity along with limnological abiotic characteristics were studied based on monthly sampling from four sampling stations (between May 2005 and April 2006). A total of 4 classes, 68 genera, and 98 species which belong to Chlorophyceae (52 species), Cyanobacteria (24 species), Bacillariophyceae (19 species), and Euglenophyceae (3 species), respectively, were identified. Phytoplankton assemblages were dominated by Cyanobacteria during summer months and were the most abundant. On an annual average scale, the phytoplankton density varied between 0.24×10(4) units/l at station 4 to 0.46×10(4) units/l at station 2, and station 2 represented highest population density. The predominant indices of the most predominant species varied between 0.03 and 0.26. Among physicochemical variables, temperature and total dissolved solids played a key role in phytoplankton growth as represented by statistical linear regression drawn between temperature, total dissolved solids, nitrate, and phytoplankton with R2 values of 0.6, 0.46, and 0.5, respectively.

  2. Diversity and dynamics of free-living and particle-associated Betaproteobacteria and Actinobacteria in relation to phytoplankton and zooplankton communities.

    PubMed

    Parveen, Bushra; Reveilliez, Jean-Philippe; Mary, Isabelle; Ravet, Viviane; Bronner, Gisèle; Mangot, Jean-François; Domaizon, Isabelle; Debroas, Didier

    2011-09-01

    The diversity of attached and free-living Actinobacteria and Betaproteobacteria, based on 16S rRNA gene sequences, was investigated in a mesotrophic lake during two periods of contrasting phytoplankton dominance. Comparison analyses showed a phylogenetic difference between attached and free-living communities for the two bacterial groups. For Betaproteobacteria, the betaI clade was detected at all sampling dates in free-living and attached bacterial communities and was the dominant clade contributing to 57.8% of the total retrieved operational taxonomic units (OTUs). For Actinobacteria, the acIV cluster was found to be dominant, followed by acI contributing to 45% and 25% of the total retrieved OTUs, respectively. This study allows the determination of eight new putative clades among the Betaproteobacteria termed lbI-lbVIII and a new putative clade named acLBI belonging to the Actinobacteria. The seasonal dynamics of phytoplankton and zooplankton communities have been reflected as changes in distinct bacterial phylotypes for both attached and free-living communities. For attached communities, relationships were observed between Actinobacteria and Chrysophyceae, and between Betaproteobacteria and Dinophyceae and Chlorophyceae biomass. On the other hand, within free-living communities, few actinobacterial clades were found to be dependent on either nutrients or phytoplankton communities, whereas Betaproteobacteria were mainly associated with biological parameters (i.e. phytoplankton and copepod communities).

  3. Temporal Succession of Ancient Phytoplankton Community in Qinghai Lake and Implication for Paleo-environmental Change.

    PubMed

    Li, Gaoyuan; Dong, Hailiang; Hou, Weiguo; Wang, Shang; Jiang, Hongchen; Yang, Jian; Wu, Geng

    2016-01-25

    Tibetan lake sediments in NW China are sensitive recorders of climate change. However, many important plankton members do not leave any microscopic features in sedimentary records. Here we used ancient DNA preserved in Qinghai Lake sediments to reconstruct the temporal succession of plankton communities in the past 18,500 years. Our results showed that seven classes and sixteen genera of phytoplankton in the lake underwent major temporal changes, in correlation with known climatic events. Trebouxiophyceae and Eustigmatophyceae were predominant during the cold periods, whereas Chlorophyceae, Phaeophyceae, Xanthophyceae, Bacillariophyceae, and Cyanophyceae were abundant during the warm periods. The inferred changes in temperature, nutrients, precipitation, and salinity, as driven by the Westerlies and summer Monsoon strength, likely contributed to these observed temporal changes. Based on these correlations, we propose the phytoplankton index as a proxy to reconstruct the stadial versus interstadial climate change history in Qinghai Lake. This taxon-specific index is free of terrestrial contamination, sensitive to short-term climatic oscillations, and continuous in recording all climatic events in the lake. The validity of this index and its applicability to other lakes is demonstrated by its good correlations with multiple climate records of Qinghai Lake and another lake on the Tibetan Plateau, Kusai Lake.

  4. Phytoplankton abundance and structure as indicator of water quality in the drainage system of the Burullus Lagoon, southern Mediterranean coast, Egypt.

    PubMed

    El-Kassas, Hala Yassin; Gharib, Samiha Mahmoud

    2016-09-01

    This study represents the first detailed account of phytoplankton community structure and seasonal succession in eight drain sites and the Brimbal Canal influx into the Burullus Lagoon. The phytoplankton characteristics were studied based on the data collected seasonally over 4 years, from summer 2012 to spring 2016. Various indices such as Palmer's and Shannon's biotic indices were used for the assessment of the water quality of the different drains. There were a total of 194 species belonging to 65 genera and 6 groups: Bacillariophyceae (76 species), Chlorophyceae (59 species), Cyanophyceae (30 species), Euglenophyceae (25 species), Dinophyceae (3 species), and Xanthophyceae (1 species). The phytoplankton community was dominated with diatoms, green algae, and euglenoids such as Cyclotella, Scenedesmus, Navicula, Nitzschia, Ankistrodesmus, Chlorella, and Euglena. Maximum and minimum phytoplankton abundance was recorded at the Brimbal Canal and Hooks Drain. Maximum and minimum species diversities (H') were found at the Hooks Drain (2.564) and Burullus Drain (2.055). Species evenness fluctuated between 0.595 (Burullus Drain) and 0.750 (West Burullus Drain). The total score of algal genus pollution index and the algal species pollution index at the different drains showed that Drain 7 and the West Burullus Drain had moderate pollution, and the total score of the other drains were greater than 20 indicating the confirmed high organic pollution. Thus, the present investigation can be considered an attempt to use the phytoplankton community as a bioindicator of organic pollution.

  5. Influence of El Niño Southern Oscillation phenomenon on coastal phytoplankton in a mixohaline ecosystem on the southeastern of South America: Río de la Plata estuary.

    PubMed

    Sathicq, María Belén; Bauer, Delia Elena; Gómez, Nora

    2015-09-15

    The aim of this study was to analyze the density, diversity, biomass and assemblage composition of the phytoplankton in relation to environmental conditions (physical, chemical, hydrological and meteorological variables), measured under the different scenarios caused by the ENSO phenomenon in the period between 2005 and 2012, in six sampling sites in the tidal freshwater zone of the Río de la Plata estuary, covering almost 100km of coastline. The results revealed changes in the structure of the phytoplankton, such as a significant reduction of diversity, and decreases in biomass and phytoplankton density, particularly during El Niño phases. Cyanobacteria were more abundant in the neutral periods, Chlorophyceae dominated La Niña phase while Bacyllariophyceae dominated El Niño. However, no complete replacement of species between cycles was observed. The results obtained were highly variable due to the inherent natural variability of the Río de la Plata, emphasized by the anthropogenic impact in this area.

  6. Water quality of a coastal lagoon (ES, Brazil): abiotic aspects, cytogenetic damage, and phytoplankton dynamics.

    PubMed

    Duarte, Ian Drumond; Silva, Nayara Heloisa Vieira Fraga; da Costa Souza, Iara; de Oliveira, Larissa Bassani; Rocha, Lívia Dorsch; Morozesk, Mariana; Bonomo, Marina Marques; de Almeida Pereira, Thaís; Dias, Mauro Cesar; de Oliveira Fernandes, Valéria; Matsumoto, Silvia Tamie

    2017-03-14

    Assessment of water resources requires interdisciplinary studies that include multiple ecosystem aspects. This study evaluated the water quality of Juara Lagoon (ES, Brazil) based on physical and chemical variables, cytogenetic responses in Allium cepa and phytoplankton dynamics. Three sampling sites were defined and water samples were collected during two sampling periods. Analyses such as determination of photic zone, conductivity, and concentrations of nutrients and metals were conducted as well as cytotoxic, mutagenic, and genotoxic potentials using A. cepa test. The main attributes of phytoplankton community, such as total richness, total density, density by class, dominance, and diversity, were also evaluated. Results have revealed that Juara Lagoon has signs of artificial eutrophication at two sampling sites due to high levels of total phosphorus and ammonia nitrogen. Cytotoxic, genotoxic, and mutagenic potentials were detected as well as high concentrations of Fe and Mn. Furthermore, 165 phytoplankton taxa were recorded, with highest richness in Chlorophyceae and Cyanophyceae classes. In addition, Cyanophyceae presented as the highest density class. A. cepa test and phytoplankton community evaluation indicated that the ecological quality of Juara Lagoon is compromised.

  7. Control of phobic behavioral responses by rhodopsin-induced photocurrents in Chlamydomonas.

    PubMed Central

    Holland, E M; Harz, H; Uhl, R; Hegemann, P

    1997-01-01

    Both phototactic and photophobic responses of Chlamydomonas are mediated by a visual system comprising a rhodopsin photoreceptor. Suction pipette recordings have revealed that flash stimulation causes calcium currents into the eyespot and the flagella. These photocurrents have been suggested to be the trigger for all behavioral light responses of the cell. But this has never been shown experimentally. Here we describe a detection technique that combines electrical and optical measurements from individual algae held in a suction pipette. Thus it is possible to record photocurrents and flagellar beating simultaneously and establish a direct link between the two. We demonstrate that in Chlamydomonas only the photoreceptor current in conjuction with a fast flagellar current constitutes the trigger for photophobic responses. Within the time of the action-potential-like flagellar current, the flagella switch from forward to backward swimming, which constitutes the beginning of the photoshock reaction. The switch is accompanied by a complex frequency change and beating pattern modulation. The results are interpreted in terms of a general model for phototransduction in green algae (Chlorophyceae). Images FIGURE 3 PMID:9284306

  8. Control of phobic behavioral responses by rhodopsin-induced photocurrents in Chlamydomonas.

    PubMed

    Holland, E M; Harz, H; Uhl, R; Hegemann, P

    1997-09-01

    Both phototactic and photophobic responses of Chlamydomonas are mediated by a visual system comprising a rhodopsin photoreceptor. Suction pipette recordings have revealed that flash stimulation causes calcium currents into the eyespot and the flagella. These photocurrents have been suggested to be the trigger for all behavioral light responses of the cell. But this has never been shown experimentally. Here we describe a detection technique that combines electrical and optical measurements from individual algae held in a suction pipette. Thus it is possible to record photocurrents and flagellar beating simultaneously and establish a direct link between the two. We demonstrate that in Chlamydomonas only the photoreceptor current in conjuction with a fast flagellar current constitutes the trigger for photophobic responses. Within the time of the action-potential-like flagellar current, the flagella switch from forward to backward swimming, which constitutes the beginning of the photoshock reaction. The switch is accompanied by a complex frequency change and beating pattern modulation. The results are interpreted in terms of a general model for phototransduction in green algae (Chlorophyceae).

  9. The GC-rich mitochondrial and plastid genomes of the green alga Coccomyxa give insight into the evolution of organelle DNA nucleotide landscape

    SciTech Connect

    Smith, David Roy; Burki, Fabien; Yamada, Takashi; Grimwood, Jane; Grigoriev, Igor V.; Van Etten, James L.; Keeling, Patrick J.; Kroymann, Juergen

    2011-08-26

    Here, most of the available mitochondrial and plastid genome sequences are biased towards adenine and thymine (AT) over guanine and cytosine (GC). Examples of GC-rich organelle DNAs are limited to a small but eclectic list of species, including certain green algae. Here, to gain insight in the evolution of organelle nucleotide landscape, we present the GC-rich mitochondrial and plastid DNAs from the trebouxiophyte green alga Coccomyxa sp. C-169. We compare these sequences with other GC-rich organelle DNAs and argue that the forces biasing them towards G and C are nonadaptive and linked to the metabolic and/or life history features of this species. The Coccomyxa organelle genomes are also used for phylogenetic analyses, which highlight the complexities in trying to resolve the interrelationships among the core chlorophyte green algae, but ultimately favour a sister relationship between the Ulvophyceae and Chlorophyceae, with the Trebouxiophyceae branching at the base of the chlorophyte crown.

  10. Inducible defenses against herbivory and fouling in seaweeds

    NASA Astrophysics Data System (ADS)

    Pereira, Renato Crespo; Costa, Erica da Silva; Sudatti, Daniela Bueno; da Gama, Bernardo Antonio Perez

    2017-04-01

    Secondary metabolites play an important ecological role as a defense mechanism in seaweeds. Chemical defenses are well known to change in response to herbivory, but other driving factors, either biotic or abiotic, are often neglected. Epibiosis may not only reduce seaweed fitness, but also increase attractiveness to consumers, and thus defense production should also be triggered by epibionts. In this study, three Southwestern Atlantic seaweeds, Gracilaria cearensis, Pterocladiella capillacea (Rhodophyceae) and Codium decorticatum (Chlorophyceae) were investigated in laboratory bioassays designed to test whether the action of herbivory or simulated epibiosis influences chemical defenses. Crossed induction experiments were also performed in order to assess whether herbivore induction influences antifouling chemical defense, as well as whether epibiont induction would affect defense against herbivores. The effect of laboratory conditions on seaweeds in the absence of field stimuli was also investigated by comparing consumption of artificial food with extracts from acclimatized and non-acclimatized seaweeds (i.e., natural defense levels). Only the green seaweed C. decorticatum exhibited inducible antifouling defenses triggered by simulated epibiosis, but not by herbivores. In the other seaweeds there was no induction either by herbivory or simulated epibiosis. Acclimatization did not affect C. decorticatum defenses. However, non-acclimatized G. cearensis artificial foods were preferred over acclimatized ones, while extracts from acclimatized P. capillacea increased herbivore consumption, highlighting the need to acclimatize seaweeds before the main induction experiments. This is the first report of inducible defenses due to simulated fouling in seaweeds.

  11. Rapid Accumulation of Total Lipid in Rhizoclonium africanum Kutzing as Biodiesel Feedstock under Nutrient Limitations and the Associated Changes at Cellular Level

    PubMed Central

    Satpati, Gour Gopal; Kanjilal, Sanjit; Narayana Prasad, Rachapudi Badari; Pal, Ruma

    2015-01-01

    Increase of total lipid and the proportion of the favorable fatty acids in marine green filamentous macroalga Rhizoclonium africanum (Chlorophyceae) was studied under nitrate and phosphate limitations. These stresses were given by both eliminating and doubling the required amounts of nitrate and phosphate salts in the growth media. A significant twofold increase in total lipid (193.03 mg/g) was achieved in cells in absence of nitrate in the culture medium, followed by phosphate limitation (142.65 mg/g). The intracellular accumulation of neutral lipids was observed by fluorescence microscopy. The scanning electron microscopic study showed the major structural changes under nutrient starvation. Fourier transform infrared spectroscopy (FTIR) revealed the presence of ester (C-O-C stretching), ketone (C-C stretching), carboxylic acid (O-H bending), phosphine (P-H stretching), aromatic (C-H stretching and bending), and alcohol (O-H stretching and bending) groups in the treated cells indicating the high accumulation of lipid hydrocarbons in the treated cells. Elevated levels of fatty acids favorable for biodiesel production, that is, C16:0, C16:1, C18:1, and C20:1, were identified under nitrate- and phosphate-deficient conditions. This study shows that the manipulation of cultural conditions could affect the biosynthetic pathways leading to increased lipid production while increasing the proportion of fatty acids suitable for biodiesel production. PMID:26880924

  12. Ecology of Baskandi anua, an oxbow lake of South Assam, North East India.

    PubMed

    Gupta, Susmita; Devi, S Sushila

    2014-11-01

    A study was made on the physico-chemical properties of water and phyto and zooplankton communities of Baskandi anua, an oxbow lake of South Assam during March to August, 2009. Analyses of water showed acidic to slightly alkaline pH (5.4-7.9) with dissolved oxygen ranging from 4.26 to 11.83 mgl(-1) and total alkalinity from 31.25 to 65 mg l(-1), indicating the productive nature of water. Free CO2 fluctuated from 2.93 to 15.04 mgl(-1). PO4 and NO3 concentration ranged from 0.15 to 1.4 mg l(-1) and 0.06 mg l(-1) to 4.94 mg l(-1), respectively. Conductivity, pH and free CO2 were found higher at the sites surrounded by paddy fields. Mean values of physico-chemical parameters significantly varied between the sites and were found to be influenced by one or more of the following factors viz. rainfall, depth and influx from adjacent paddy field. A total of 30 phytoplankton taxa and 12 zooplankton taxa with qualitative dominance of Chlorophyceae were recorded. The study revealed that water quality of the lake was good for aquaculture. Hence, the lake should be protected and best management practices should be implemented for sustainable production.

  13. Effects of hydraulic retention time on cultivation of indigenous microalgae as a renewable energy source using secondary effluent.

    PubMed

    Takabe, Yugo; Hidaka, Taira; Tsumori, Jun; Minamiyama, Mizuhiko

    2016-05-01

    Secondary effluent from wastewater treatment plants is suitable media for cultivating microalgae as a renewable energy source, and hydraulic retention time (HRT) control in culture is important to conduct well-planned outdoor indigenous microalgae cultivation with secondary effluent. This study revealed cultivation characteristics under various HRT by continuous 6-month experiments. In addition, effects of HRT on cultivation were determined by a mathematical model that described indigenous microalgae growth. Cultivated biomass mainly consisted of Chlorophyceae and its detritus regardless of HRT, and 5.93-14.8g/m(2)/day of biomass yield was obtained. The cultivated biomass had a stable higher heating value of 16kJ/g. Sensitivity analysis of the model suggests that HRT control had great effects on biomass yield, and 2-3days of HRT were recommended to obtain maximum biomass yield under certain weather conditions (temperature: approximately 12-25°C and solar radiation: approximately 8-19MJ/m(2)/day). Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Effects of iso-nutrient fertilization on plankton production in earthen ponds of Bangladesh.

    PubMed

    Begum, Momtaz; Hossain, Md Yeamin; Wahab, Md Abdul; Ahmed, Zoarder Faruque; Alam, Md Jahangir; Shah, Md Mahfuzur Rahman; Jasmine, Saleha

    2007-04-15

    The experiment was conducted to evaluate the effects of iso-nutrients fertilization on fertilizer combinations, containing a similar amount of nitrogen (N) and phosphorus (P) were the production of plankton in earthen ponds for a period of eight weeks. Two different were tested in triplicate using six earthen ponds of 100 m2 each. The fertilizer combinations of cow manure, urea and Triple Super Phosphate (TSP) at the rate 5000, 125 and 100 kg ha(-1), respectively, containing approximately 102 kg N and 65 kg P was used for treatment-1 (T-l). Another combination of poultry-manure, urea and TSP at the rate of 2000, 125 and 100 kg ha(-1), respectively, was considered as the treatment-2 (T-2). The application rate of poultry manure was adjusted to make the nutrient (N and P) content of fertilizer combination in T-2 similar to that in T-1. Four groups of phytoplankton namely, Bacillariophyceae, Chlorophyceae, Cyanophyceae and Euglenophyceae and two groups of zooplankton namely, Crustacea and Rotifera were identified. The mean abundance of both phytoplankton (78.25 +/- 6.33 x 10(4) cells L(-1)) and zooplankton (57.63 +/- 4.59 x 10(4) cells L(-1)), were significantly higher (p < 0.05) in earthen ponds which treated with poultry manure. The result showed that despite iso-nutrients content, the nutrient status of poultry manure proved to be superior to cow manure.

  15. The GC-rich mitochondrial and plastid genomes of the green alga Coccomyxa give insight into the evolution of organelle DNA nucleotide landscape

    DOE PAGES

    Smith, David Roy; Burki, Fabien; Yamada, Takashi; ...

    2011-08-26

    Here, most of the available mitochondrial and plastid genome sequences are biased towards adenine and thymine (AT) over guanine and cytosine (GC). Examples of GC-rich organelle DNAs are limited to a small but eclectic list of species, including certain green algae. Here, to gain insight in the evolution of organelle nucleotide landscape, we present the GC-rich mitochondrial and plastid DNAs from the trebouxiophyte green alga Coccomyxa sp. C-169. We compare these sequences with other GC-rich organelle DNAs and argue that the forces biasing them towards G and C are nonadaptive and linked to the metabolic and/or life history features ofmore » this species. The Coccomyxa organelle genomes are also used for phylogenetic analyses, which highlight the complexities in trying to resolve the interrelationships among the core chlorophyte green algae, but ultimately favour a sister relationship between the Ulvophyceae and Chlorophyceae, with the Trebouxiophyceae branching at the base of the chlorophyte crown.« less

  16. Diversity and Dynamics of Active Small Microbial Eukaryotes in the Anoxic Zone of a Freshwater Meromictic Lake (Pavin, France).

    PubMed

    Lepère, Cécile; Domaizon, Isabelle; Hugoni, Mylène; Vellet, Agnès; Debroas, Didier

    2016-01-01

    Microbial eukaryotes play a crucial role in ecosystem functioning and oxygen is considered to be one of the strongest barriers against their local dispersal. However, diversity of microbial eukaryotes in freshwater habitats with oxygen gradients has previously received very little attention. We applied high-throughput sequencing (V4 region of the 18S rRNA gene) in conjunction with quantitative PCR (DNA and RNA) and fluorescent in situ hybridization (FISH) analyses, to provide an unique spatio-temporal analysis of microbial eukaryotes diversity and potential activity in a meromictic freshwater lake (lake Pavin). This study revealed a high genetic diversity of unicellular eukaryotes in the permanent anoxic zone of lake Pavin and allowed the discrimination of active vs. inactive components. Forty-two percent of the OTUs (Operational Taxonomic Units) are exclusively present in the monimolimnion, where Alveolata (Ciliophora and Dinophyceae) and Fungi (Dikarya and Chytrids) are the most active phyla and are probably represented by species capable of anaerobic metabolism. Pigmented eukaryotes (Haptophyceae and Chlorophyceae) are also present and active in this zone, which opens up questions regarding their metabolism.

  17. Diversity and Dynamics of Active Small Microbial Eukaryotes in the Anoxic Zone of a Freshwater Meromictic Lake (Pavin, France)

    PubMed Central

    Lepère, Cécile; Domaizon, Isabelle; Hugoni, Mylène; Vellet, Agnès; Debroas, Didier

    2016-01-01

    Microbial eukaryotes play a crucial role in ecosystem functioning and oxygen is considered to be one of the strongest barriers against their local dispersal. However, diversity of microbial eukaryotes in freshwater habitats with oxygen gradients has previously received very little attention. We applied high-throughput sequencing (V4 region of the 18S rRNA gene) in conjunction with quantitative PCR (DNA and RNA) and fluorescent in situ hybridization (FISH) analyses, to provide an unique spatio-temporal analysis of microbial eukaryotes diversity and potential activity in a meromictic freshwater lake (lake Pavin). This study revealed a high genetic diversity of unicellular eukaryotes in the permanent anoxic zone of lake Pavin and allowed the discrimination of active vs. inactive components. Forty-two percent of the OTUs (Operational Taxonomic Units) are exclusively present in the monimolimnion, where Alveolata (Ciliophora and Dinophyceae) and Fungi (Dikarya and Chytrids) are the most active phyla and are probably represented by species capable of anaerobic metabolism. Pigmented eukaryotes (Haptophyceae and Chlorophyceae) are also present and active in this zone, which opens up questions regarding their metabolism. PMID:26904006

  18. Changes in epiphytic bacterial communities of intertidal seaweeds modulated by host, temporality, and copper enrichment.

    PubMed

    Hengst, Martha B; Andrade, Santiago; González, Bernardo; Correa, Juan A

    2010-08-01

    This study reports on the factors involved in regulating the composition and structure of bacterial communities epiphytic on intertidal macroalgae, exploring their temporal variability and the role of copper pollution. Culture-independent, molecular approaches were chosen for this purpose and three host species were used as models: the ephemeral Ulva spp. (Chlorophyceae) and Scytosiphon lomentaria (Phaeophyceae) and the long-living Lessonia nigrescens (Phaeophyceae). The algae were collected from two coastal areas in Northern Chile, where the main contrast was the concentration of copper in the seawater column resulting from copper-mine waste disposals. We found a clear and strong effect in the structure of the bacterial communities associated with the algal species serving as host. The structure of the bacterial communities also varied through time. The effect of copper on the structure of the epiphytic bacterial communities was significant in Ulva spp., but not on L. nigrescens. The use of 16S rRNA gene library analysis to compare bacterial communities in Ulva revealed that they were composed of five phyla and six classes, with approximately 35 bacterial species, dominated by members of Bacteroidetes (Cytophaga-Flavobacteria-Bacteroides) and α-Proteobacteria, in both non-polluted and polluted sites. Less common groups, such as the Verrucomicrobiae, were exclusively found in polluted sites. This work shows that the structure of bacterial communities epiphytic on macroalgae is hierarchically determined by algal species > temporal changes > copper levels.

  19. ANALYSIS OF A PLASTID MULTIGENE DATA SET AND THE PHYLOGENETIC POSITION OF THE MARINE MACROALGA CAULERPA FILIFORMIS (CHLOROPHYTA)(1).

    PubMed

    Zuccarello, G C; Price, Natalie; Verbruggen, Heroen; Leliaert, Frederik

    2009-10-01

    Molecular phylogenetic relationships within the Chlorophyta have relied heavily on rRNA data. These data have revolutionized our insight in green algal evolution, yet some class relationships have never been well resolved. A commonly used class within the Chlorophyta is the Ulvophyceae, although there is not much support for its monophyly. The relationships among the Ulvophyceae, Trebouxiophyceae, and Chlorophyceae are also contentious. In recent years, chloroplast genome data have shown their utility in resolving relationships between the main green algal clades, but such studies have never included marine macroalgae. We provide partial chloroplast genome data (∼30,000 bp, 23 genes) of the ulvophycean macroalga Caulerpa filiformis (Suhr) K. Herig. We show gene order conservation for some gene combinations and rearrangements in other regions compared to closely related taxa. Our data also revealed a pseudogene (ycf62) in Caulerpa species. Our phylogenetic results, based on analyses of a 23-gene alignment, suggest that neither Ulvophyceae nor Trebouxiophyceae are monophyletic, with Caulerpa being more closely related to the trebouxiophyte Chlorella than to Oltmannsiellopsis and Pseudendoclonium. © 2009 Phycological Society of America.

  20. Membrane Proteomic Insights into the Physiology and Taxonomy of an Oleaginous Green Microalga.

    PubMed

    Garibay-Hernández, Adriana; Barkla, Bronwyn J; Vera-Estrella, Rosario; Martinez, Alfredo; Pantoja, Omar

    2017-01-01

    Ettlia oleoabundans is a nonsequenced oleaginous green microalga. Despite the significant biotechnological interest in producing value-added compounds from the acyl lipids of this microalga, a basic understanding of the physiology and biochemistry of oleaginous microalgae is lacking, especially under nitrogen deprivation conditions known to trigger lipid accumulation. Using an RNA sequencing-based proteomics approach together with manual annotation, we are able to provide, to our knowledge, the first membrane proteome of an oleaginous microalga. This approach allowed the identification of novel proteins in E. oleoabundans, including two photoprotection-related proteins, Photosystem II Subunit S and Maintenance of Photosystem II under High Light1, which were considered exclusive to higher photosynthetic organisms, as well as Retinitis Pigmentosa Type 2-Clathrin Light Chain, a membrane protein with a novel domain architecture. Free-flow zonal electrophoresis of microalgal membranes coupled to liquid chromatography-tandem mass spectrometry proved to be a useful technique for determining the intracellular location of proteins of interest. Carbon-flow compartmentalization in E. oleoabundans was modeled using this information. Molecular phylogenetic analyses of protein markers and 18S ribosomal DNA support the reclassification of E. oleoabundans within the trebouxiophycean microalgae, rather than with the Chlorophyceae class, in which it is currently classified, indicating that it may not be closely related to the model green alga Chlamydomonas reinhardtii A detailed survey of biological processes taking place in the membranes of nitrogen-deprived E. oleoabundans, including lipid metabolism, provides insights into the basic biology of this nonmodel organism.

  1. On the natural diet of Daphnia laevis in the eutrophic Pampulha reservoir (Belo Horizonte, Minas Gerais).

    PubMed

    Eskinazi-Sant'Anna, E M; Maia-Barbosa, P M; Barbosa, F A R

    2002-08-01

    The aim of this study was to assess the major food items ingested by adult specimens of Daphnia laevis within the eutrophic Pampulha reservoir in Belo Horizonte, Minas Gerais, Brazil. The gut content was analyzed after addition of sodium hypochlorite and also through the examination of dissected guts under scanning electron microscopy. The results showed that Chlorophyceae was the main food item ingested, representing c. 80.5% of the total ingested food. Moreover, Eutetramorus fottii, Coelastrum pseudomicroporum and Oocystis lacustris, the dominant phytoplankton species within the reservoir, were the most frequent cells found in the gut contents. Euglenophyta also represented an important food item accounting for 15% of the ingested material, including mainly Trachelomonas volvocina and Euglena oxyuris, although less abundant in the reservoir (< 10% of total phytoplankton). Blue-green algae occurred at much lower percentages in the guts than in the phytoplankton. A small amount of undigested Microcystis aeruginosa colonies were also found in the gut content of D. laevis. Scanning electron microscopy results showed that, besides phytoplankton cells, a great amount of abiogenic material was also ingested. The amount of this inorganic material increased considerably in the tract (from 15% to 75% of the gut content), when a peak of D. laevis was observed in the reservoir. Our assumption is that the ingestion of this inorganic material can be a strategy used by D. laevis to obtain additional food supply.

  2. Effect of intracellular P content on phosphate removal in Scenedesmus sp. Experimental study and kinetic expression.

    PubMed

    Ruiz-Martínez, A; Serralta, J; Romero, I; Seco, A; Ferrer, J

    2015-01-01

    The present work determines the effect of phosphorus content on phosphate uptake rate in a mixed culture of Chlorophyceae in which the genus Scenedesmus dominates. Phosphate uptake rate was determined in eighteen laboratory batch experiments, with samples taken from a progressively more P-starved culture in which a minimum P content of 0.11% (w/w) was achieved. The results obtained showed that the higher the internal biomass P content, the lower the phosphate removal rate. The highest specific phosphate removal rate was 6.5mgPO4-PgTSS(-1)h(-1). Microalgae with a P content around 1% (w/w) attained 10% of this highest removal rate, whereas those with a P content of 0.6% (w/w) presented 50% of the maximum removal rate. Different kinetic expressions were used to reproduce the experimental data. Best simulation results for the phosphate uptake process were obtained combining Steele equation and Hill function to represent the effect of light and intracellular phosphorus content, respectively.

  3. 'Candidatus Megaira polyxenophila' gen. nov., sp. nov.: considerations on evolutionary history, host range and shift of early divergent rickettsiae.

    PubMed

    Schrallhammer, Martina; Ferrantini, Filippo; Vannini, Claudia; Galati, Stefano; Schweikert, Michael; Görtz, Hans-Dieter; Verni, Franco; Petroni, Giulio

    2013-01-01

    "Neglected Rickettsiaceae" (i.e. those harboured by non-hematophagous eukaryotic hosts) display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure) of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora); furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta). Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales) as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria.

  4. Charge displacement by adhesion and spreading of a cell.

    PubMed

    Svetlicić, V; Ivosević, N; Kovac, S; Zutić, V

    2001-01-01

    The potentiostatic control of surface charge density and interfacial tension of an electrode immersed in an aqueous electrolyte solution offers a possibility for direct studies of non-specific interactions in cell adhesion. Unicellular marine alga, Dunaliella tertiolecta (Chlorophyceae) of micrometer size and flexible cell envelope was used as a model cell and 0.1 M NaCl as supporting electrolyte. The dropping mercury electrode acted as in situ adhesion sensor and the electrochemical technique of chronoamperometry allowed measurement of the spread cell-electrode interface area and the distance of the closest approach of a cell. The adhesion and spreading of a single cell at the mercury electrode causes a displacement of counter-ions from the electrical double layer over a broad range of the positive and negative surface charge densities (from +16.0 to -8.2 microC/cm2). The flow of compensating current reflects the dynamics of adhesive contact formation and subsequent spreading of a cell. The adhesion and spreading rates are enhanced by the hydrodynamic regime of electrode's growing fluid interface. The distance of the closest approach of an adherent cell is smaller or equal to the distance of the outer Helmholz plane within the electrical double layer, i.e. 0.3-0.5 nm. There is a clear evidence of cell rupture for the potentials of maximum attraction as the area of the contact interface exceeded up to 100 times the cross-section area of a free cell.

  5. The concept of ecological succession applied to phytoplankton over four consecutive years in five ponds featuring a salinity gradient

    NASA Astrophysics Data System (ADS)

    Khemakhem, Hajer; Elloumi, Jannet; Moussa, Mahmoud; Aleya, Lotfi; Ayadi, Habib

    2010-06-01

    The distribution of phytoplankton abundance, biomass and species composition coupled with environmental factors and metazooplankton was studied relatively intensively and over a period of four consecutive years in five ponds featuring a gradient of increasing salinity from near to that of sea water to a nine-fold concentration from 2000 to 2003. The results indicate that the physical characteristics of the water (temperature and salinity) were quite similar over the years. Nutrients, which were concentrated in pond A1, decreased with increases in salt concentration. The composition of the phytoplankton community showed strong seasonality. Diatoms dominated in the first ponds A1, A16 and C2-1, followed by dinoflagellates. Chlorophyceae dominated the phytoplankton community in the hypersaline ponds M2 and TS. Cyanobacteriae were relatively abundant in ponds M2 and TS. The highest phytoplankton density and biomass were found in the ponds with the highest salinity due to the proliferation of Dunaliella salina (Chlorophyta: Volvocales). The inter-annual study of phytoplankton succession in the Sfax solar salterns showed slight differences among the years of study due to the stability of the environmental conditions. Phytoplankton communities were permanently primitive, stage 1 - structured as they failed to build complexity because of salt stress which operates for longer and above any other variables. This reduced frequency of disturbance to the existing course of regulation, allowed the community to "mature" from its "primitive" state, rather than experience frequent structural setbacks.

  6. Precambrian palaeontology in the light of molecular phylogeny - an example: the radiation of the green algae

    NASA Astrophysics Data System (ADS)

    Teyssèdre, B.

    2007-09-01

    The problem of the antiquity of the radiation of the green algae (phylum Viridiplantae) has been hotly debated and is still controversial today. A method combining Precambrian paleontology and molecular phylogeny is applied to shed light on this topic. As a critical method, molecular phylogeny is essential for avoiding taxonomic mistakes. As a heuristic method, it helps us to discern to what extent the presence of such and such clade is likely at such and such time, and it may even suggest the attribution of some fossil to a clade whose taxonomic position will be distinctly defined even though it has no previously known representative. Some well characterized Precambrian fossils of green algae are Palaeastrum and Proterocladus at Svanbergfjellet (ca. 750 Ma), Tasmanites and Pterospermella at Thule (ca. 1200 Ma), Spiromorpha at Ruyang (ca. 1200 Ma) and Leiosphaeridia crassa at Roper (ca. 1450 Ma). The position of these fossils in the taxonomy and the phylogeny of the Viriplantae is discussed. The conclusions are that the Chlorophyceae and the Ulvophyceae were separated long before 750 Ma, that the Chlorophyta and the Streptophyta were separated long before 1200 Ma and that the last common ancestor of the Viridiplantae and the Rhodophyta was possibly two billion years old.

  7. Interpretation of an index of phytoplankton population composition calculated from Remote Airborne Fluorsensor (RAF) data

    NASA Technical Reports Server (NTRS)

    Farmer, F. H.

    1981-01-01

    The calculation of indices of phytoplankton population composition from chlorophyll a fluorescence at 685 nm excited by narrow band light at 454 and 539 nm is discussed. The ratio of the fluorescence excited by light of these two wavelengths is a function of the distribution of the phytoplankton between two color groups, designated the golden-brown and the green. The golden-brown group consists of those species which have the highly photosynthetically active carotenoid-chlorophyll-a-protein complexes, i.e. members of the classes Bacillariophyceae, diatoms Dinophyceae, dinoflagellates, and some members of the class Prymnesiophyceae. The green color group consists those species of phytoplankton which apparently lack those complexes, i.e. members of the classes Chlorophyceae, Euglenophyceae, Prasinophyceae, Eustigmatophyceae, Xanthophyceae, and a few members of the Prymnesiophyceae. A few species of phytoplankton appear to have intermediate characteristics, and would apparently belong to neither group. Most of these species are members of the class Cryptophyceae. The composition index for this class is examined in detail.

  8. The green seaweed Ulva: a model system to study morphogenesis

    PubMed Central

    Wichard, Thomas; Charrier, Bénédicte; Mineur, Frédéric; Bothwell, John H.; Clerck, Olivier De; Coates, Juliet C.

    2015-01-01

    Green macroalgae, mostly represented by the Ulvophyceae, the main multicellular branch of the Chlorophyceae, constitute important primary producers of marine and brackish coastal ecosystems. Ulva or sea lettuce species are some of the most abundant representatives, being ubiquitous in coastal benthic communities around the world. Nonetheless the genus also remains largely understudied. This review highlights Ulva as an exciting novel model organism for studies of algal growth, development and morphogenesis as well as mutualistic interactions. The key reasons that Ulva is potentially such a good model system are: (i) patterns of Ulva development can drive ecologically important events, such as the increasing number of green tides observed worldwide as a result of eutrophication of coastal waters, (ii) Ulva growth is symbiotic, with proper development requiring close association with bacterial epiphytes, (iii) Ulva is extremely developmentally plastic, which can shed light on the transition from simple to complex multicellularity and (iv) Ulva will provide additional information about the evolution of the green lineage. PMID:25745427

  9. Studies on phytoplankton characteristics in Ayyampattinam coast, India.

    PubMed

    Kumar, C Santhosh; Perumal, P

    2012-05-01

    Physico-chemical variables in the marine environment are subjected to wide spatio-temporal variations. The various physico-chemical parameters viz: temperature, salinity, pH, dissolved oxygen and nutrients of the environment are the factors which mainly influence the production and successful propagation of planktonic life in the coastal biotopes. The ranges of values of surface water temperature (0 degrees C), salinity (per thousand), pH and dissolved oxygen (ml l(-1)) were: 25.5 - 33.4; 23 - 35; 7.8 - 8.2; 3.6 - 5.2, respectively. The values (microg l(-1)) of nutrients were: nitrate 3.21 - 6.34, nitrite 0.74 - 0.896, phosphate 0.22 and 1.16, silicate 24.85 - 61.92 and ammonia 0.05 - 0.32. The recorded values of primary productivity (mgcm(-3)hr(1)) ranged between 16 - 116 and the chlorophyll "a" varied from 3.74 - 8.52. A total number of 51 species of phytoplankton representing different classes viz: Bacillariophyceae (40); Dinophyceae (8); Chlorophyceae (1) and Cyanophyceae (2) was recorded. Among the four classes, Bacillariophyceae appeared to be the dominant group in respect of total species and cell numbers. The population density of phytoplankton was high during summer season and quite low during monsoon season.

  10. Biological Soil Crusts of Arctic Svalbard—Water Availability as Potential Controlling Factor for Microalgal Biodiversity

    PubMed Central

    Borchhardt, Nadine; Baum, Christel; Mikhailyuk, Tatiana; Karsten, Ulf

    2017-01-01

    In the present study the biodiversity of biological soil crusts (BSCs) formed by phototrophic organisms were investigated on Arctic Svalbard (Norway). These communities exert several important ecological functions and constitute a significant part of vegetation at high latitudes. Non-diatom eukaryotic microalgal species of BSCs from 20 sampling stations around Ny-Ålesund and Longyearbyen were identified by morphology using light microscopy, and the results revealed a high species richness with 102 species in total. 67 taxa belonged to Chlorophyta (31 Chlorophyceae and 36 Trebouxiophyceae), 13 species were Streptophyta (11 Klebsormidiophyceae and two Zygnematophyceae) and 22 species were Ochrophyta (two Eustigmatophyceae and 20 Xanthophyceae). Surprisingly, Klebsormidium strains belonging to clade G (Streptophyta), which were so far described from Southern Africa, could be determined at 5 sampling stations. Furthermore, comparative analyses of Arctic and Antarctic BSCs were undertaken to outline differences in species composition. In addition, a pedological analysis of BSC samples included C, N, S, TP (total phosphorus), and pH measurements to investigate the influence of soil properties on species composition. No significant correlation with these chemical soil parameters was confirmed but the results indicated that pH might affect the BSCs. In addition, a statistically significant influence of precipitation on species composition was determined. Consequently, water availability was identified as one key driver for BSC biodiversity in Arctic regions. PMID:28848507

  11. Biological Soil Crusts of Arctic Svalbard-Water Availability as Potential Controlling Factor for Microalgal Biodiversity.

    PubMed

    Borchhardt, Nadine; Baum, Christel; Mikhailyuk, Tatiana; Karsten, Ulf

    2017-01-01

    In the present study the biodiversity of biological soil crusts (BSCs) formed by phototrophic organisms were investigated on Arctic Svalbard (Norway). These communities exert several important ecological functions and constitute a significant part of vegetation at high latitudes. Non-diatom eukaryotic microalgal species of BSCs from 20 sampling stations around Ny-Ålesund and Longyearbyen were identified by morphology using light microscopy, and the results revealed a high species richness with 102 species in total. 67 taxa belonged to Chlorophyta (31 Chlorophyceae and 36 Trebouxiophyceae), 13 species were Streptophyta (11 Klebsormidiophyceae and two Zygnematophyceae) and 22 species were Ochrophyta (two Eustigmatophyceae and 20 Xanthophyceae). Surprisingly, Klebsormidium strains belonging to clade G (Streptophyta), which were so far described from Southern Africa, could be determined at 5 sampling stations. Furthermore, comparative analyses of Arctic and Antarctic BSCs were undertaken to outline differences in species composition. In addition, a pedological analysis of BSC samples included C, N, S, TP (total phosphorus), and pH measurements to investigate the influence of soil properties on species composition. No significant correlation with these chemical soil parameters was confirmed but the results indicated that pH might affect the BSCs. In addition, a statistically significant influence of precipitation on species composition was determined. Consequently, water availability was identified as one key driver for BSC biodiversity in Arctic regions.

  12. Temporal Succession of Ancient Phytoplankton Community in Qinghai Lake and Implication for Paleo-environmental Change

    NASA Astrophysics Data System (ADS)

    Li, Gaoyuan; Dong, Hailiang; Hou, Weiguo; Wang, Shang; Jiang, Hongchen; Yang, Jian; Wu, Geng

    2016-01-01

    Tibetan lake sediments in NW China are sensitive recorders of climate change. However, many important plankton members do not leave any microscopic features in sedimentary records. Here we used ancient DNA preserved in Qinghai Lake sediments to reconstruct the temporal succession of plankton communities in the past 18,500 years. Our results showed that seven classes and sixteen genera of phytoplankton in the lake underwent major temporal changes, in correlation with known climatic events. Trebouxiophyceae and Eustigmatophyceae were predominant during the cold periods, whereas Chlorophyceae, Phaeophyceae, Xanthophyceae, Bacillariophyceae, and Cyanophyceae were abundant during the warm periods. The inferred changes in temperature, nutrients, precipitation, and salinity, as driven by the Westerlies and summer Monsoon strength, likely contributed to these observed temporal changes. Based on these correlations, we propose the phytoplankton index as a proxy to reconstruct the stadial versus interstadial climate change history in Qinghai Lake. This taxon-specific index is free of terrestrial contamination, sensitive to short-term climatic oscillations, and continuous in recording all climatic events in the lake. The validity of this index and its applicability to other lakes is demonstrated by its good correlations with multiple climate records of Qinghai Lake and another lake on the Tibetan Plateau, Kusai Lake.

  13. Response of arctic snow and permafrost algae to high light and nitrogen stress by changes in pigment composition and applied aspects for biotechnology.

    PubMed

    Leya, Thomas; Rahn, Andreas; Lütz, Cornelius; Remias, Daniel

    2009-03-01

    Ten algal strains from snow and permafrost substrates were tested for their ability to produce secondary carotenoids and alpha-tocopherol in response to high light and decreased nitrogen levels. The Culture Collection of Cryophilic Algae at Fraunhofer IBMT in Potsdam served as the bioresource for this study. Eight of the strains belong to the Chlorophyceae and two strains are affiliated to the Trebouxiophyceae. While under low light, all 10 strains produced the normal spectrum of primary pigments known to be present in Chlorophyta, only the eight chlorophyceaen strains were able to synthesize secondary carotenoids under stress conditions, namely canthaxanthin, echinenone and astaxanthin; seven of them were also able to synthesize minor amounts of adonixanthin and an unidentified hydroxyechinenone. The two trebouxiophyceaen species of Raphidonema exhibited an unusually high pool of primary xanthophyll cycle pigments, possibly serving as a buffering reservoir against excessive irradiation. They also proved to be good alpha-tocopherol producers, which might also support the deactivation of reactive oxygen species. This study showed that some strains might be interesting novel candidates for biotechnological applications. Cold-adapted, snow and permafrost algae might serve as valuable production strains still exhibiting acceptable growth rates during the cold season in temperate regions.

  14. Phytoplankton community dynamics in an intermittently open hypereutrophic coastal lagoon in southern Portugal

    NASA Astrophysics Data System (ADS)

    Coelho, Susana; Pérez-Ruzafa, Angel; Gamito, Sofia

    2015-12-01

    Phytoplankton community' dynamics were studied in Salgados coastal lagoon in order to evaluate the effects of excessive organic loads and also physical stress caused by the irregular opening of the lagoon. Salgados is a hypereutrophic intermittently open coastal lagoon, which received freshwater inputs from small rivers and from a wastewater treatment plant. Cyanophyceae dominated the phytoplankton communities most of the time; Bacillariophyceae became the main taxonomic group in winter when the lagoon was closed; Chlorophyceae was the major class in early summer; pico-nano flagellate algae accounted for a high percentage of total phytoplankton during spring. Potentially harmful taxa were observed during most of the sampling periods, forming blooms and accounting for a considerable percentage of total phytoplankton abundance. A strong differentiation among dry and wet seasons could be noticed. The dry season was dominated by Microsystis aeruginosa, Rhodomonas sp., pico-nano flagellate algae, Cyclotella spp. and Planktothrix sp., while the wet season, although still with the presence of Microsystis aeruginosa, was dominated by Dolichospermum spiroides. The best environmental variables explaining stations patterns and based on phytoplankton taxa were days of isolation, pH, and salinity. Temperature, cumulative rain and total phosphorus were also related with species and stations patterns. The high nutrient load in Salgados lagoon promoted the development and persistence of harmful algae blooms. Proper management of coastal lagoons involves not only the control of direct discharges of nutrients, but also of other factors, including water level and communication with the sea.

  15. Isolation and characterization of high quality DNA from marine benthic macroalgae.

    PubMed

    Chakraborty, S; Vijayan, K; Nair, C V; Santra, S C; Bhattacharya, T

    2008-11-01

    The isolation of high quality DNA is essential for many molecular biology applications including polymerase chain reaction (PCR) and endonuclease restriction digestion based techniques. An easy and inexpensive protocol has been developed for extracting genomic DNA from seven species of algae viz. Lola capillaries, Enteromorpha intestinalis, Ulva lactuca and Rhizoclonium sp belonging to Chlorophyceae, Catenella nipae, Polysiphonia mollis belonging to Rhodophyceae and Dictyota ceylanica belonging to Phaeophyceae group were collected from the coastal regions of Sunderban delta in West Bengal, India dominantly growing on mud flats, bark of different mangrove trees, pneumatophores, stilt roots, concrete surfaces, wooden and bamboo poles, sides of the boats and other water vehicles inundated during high tides. The DNA was found suitable for restriction endonuclease digestion and PCR amplification with randomely amplified polymorphic DNA (RAPD) primers. The A260/A280 ratio of 1.15 0.14 to 1.94 indicated little contamination from proteins and polysaccharides. The PCR amplification with RAPD primers showed its suitability in PCR based techniques and the restriction digestion with Eco RV confirmed its suitability for hybridization based techniques. The protocol is equally good for isolating DNA from both fresh as well as preserved materials.

  16. Tracking a century of changes in microbial eukaryotic diversity in lakes driven by nutrient enrichment and climate warming.

    PubMed

    Capo, Eric; Debroas, Didier; Arnaud, Fabien; Perga, Marie-Elodie; Chardon, Cécile; Domaizon, Isabelle

    2017-07-01

    High-throughput sequencing of sedimentary DNA (sed-DNA) was utilized to reconstruct the temporal dynamics of microbial eukaryotic communities (MECs) at a centennial scale in two re-oligotrophicated lakes that were exposed to different levels of phosphorus enrichment. The temporal changes within the MECs were expressed in terms of richness, composition and community structure to investigate their relationships with two key forcing factors (i.e., nutrient enrichment and climate warming). Various groups, including Apicomplexa, Cercozoa, Chrysophyceae, Ciliophora, Chlorophyceae and Dinophyceae, responded to phosphorus enrichment levels with either positive or negative impacts on their richness and relative abundance. For both lakes, statistical modelling demonstrated that phosphorus concentration ([P]) was a dominant contributor to MECs modifications before the 1980s; after the mid-80s, the contribution of air temperature changes increased and potentially surpassed the contribution of [P]. Co-occurrence network analysis revealed that some clusters of taxa (i.e., modules) composed mainly of Dinophyceae and unclassified Alveolata were strongly correlated to air temperature in both lakes. Overall, our data showed that sed-DNA constitutes a precious archive of information on past biodiversity changes, allowing the study of the dynamics of numerous eukaryotic groups that were not traditionally considered in paleo-reconstructions. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. DNA nucleoside composition and methylation in several species of microalgae

    SciTech Connect

    Jarvis, E.E.; Dunahay, T.G.; Brown, L.M. )

    1992-06-01

    Total DNA was isolated from 10 species of microalgae, including representatives of the Chlorophyceae (Chlorella ellipsoidea, Chlamydomonas reinhardtii, and Monoraphidium minutum), Bacillariophyceae (Cyclotella cryptica, Navicula saprophila, Nitzschia pusilla, and Phaeodactylum tricornutum), Charophyceae (Stichococcus sp.), Dinophyceae (Crypthecodinium cohnii), and Prasinophyceae (Tetraselmis suecica). Control samples of Escherichia coli and calf thymus DNA were also analyzed. The nucleoside base composition of each DNA sample was determined by reversed-phase high performance liquid chromatography. All samples contained 5-methyldeoxycytidine, although at widely varying levels. In M. minutum, about one-third of the cytidine residues were methylated. Restriction analysis supported this high degree of methylation in M. minutum and suggested that methylation is biased toward 5[prime]-CG dinucleotides. The guanosine + cytosine (GC) contents of the green algae were, with the exception of Stichococcus sp., consistently higher than those of the diatoms. Monoraphidium minutum exhibited an extremely high GC content of 71%. Such a value is rare among eukaryotic organisms and might indicate an unusual codon usage. This work is important for developing strategies for transformation and gene cloning in these algae. 46 refs., 1 fig., 2 tabs.

  18. Phytoplankton distribution and community structure in estuary and fishpond at Subang, Blanakan, West Java

    NASA Astrophysics Data System (ADS)

    Amadea, E.; Takarina, N. D.; Wardhana, W.

    2017-07-01

    Phytoplankton plays an important role as primary producer and denotes the fertility of territorial waters. Samples were taken from a fishpond and estuary on August 27th, 2016 at Subang, West Java. The purpose of this research was to understand how the distribution and community structure of phytoplankton on fishpond and estuary differ. The result showed that phytoplankton found were composed by 6 classes: Cyanophyceae, Euglenophyceae, Chlorophyceae, Bacillariophyceae, Dinophyceae, and Xanthophyceae. Dinophyceae was found only in estuary, and Xanthophyceae was found only in the fishpond. Index of diversity (H') in the estuary was 2.41 and value of evenness (E) was 0.73. In fishpond, the value of H' was 1.63 and the value of E was 0.59, which shows no significance difference between the two locations. However, there was a difference between the number of Bacillariophyceae and Euglenophyceae found in both locations, and the difference between classes of phytoplankton found shows there might be some relations to the environmental parameters.

  19. Selection of native Tunisian microalgae for simultaneous wastewater treatment and biofuel production.

    PubMed

    Jebali, A; Acién, F G; Gómez, C; Fernández-Sevilla, J M; Mhiri, N; Karray, F; Dhouib, A; Molina-Grima, E; Sayadi, S

    2015-12-01

    This paper focuses on the selection of native microalgae strains suitable for wastewater treatment and biofuel production. Four Chlorophyceae strains were isolated from North-eastern Tunisia. Their performances were compared in continuous mode at a 0.3 1/day dilution rate. The biomass productivity and nutrient removal capacity of each microalgae strain were studied. The most efficient strain was identified as Scenedesmus sp. and experiments at different dilution rates from 0.2 to 0.8 1/day were carried out. Maximal biomass productivity of 0.9 g/L day was obtained at 0.6 1/day. The removal of chemical oxygen demand (COD), ammonium and phosphorus was in the range of 92-94%, 61-99% and 93-99%, respectively. Carbohydrates were the major biomass fraction followed by lipids and then proteins. The saponifiable fatty acid content was in the 4.9-13.2% dry biomass range, with more than 50% of total fatty acids being composed of saturated and monosaturated fatty acids.

  20. Use of in vivo phycocyanin fluorescence to monitor potential microcystin-producing cyanobacterial biovolume in a drinking water source.

    PubMed

    McQuaid, N; Zamyadi, A; Prévost, M; Bird, D F; Dorner, S

    2011-02-01

    The source water of a drinking water treatment plant prone to blooms, dominated by potential microcystin-producing cyanobacteria, was monitored for two seasons in 2007-2008. In the 2008 season, the median value for potential microcystin-producing cyanobacterial biovolume was 87% of the total phytoplankton biovolume in the untreated water of the plant. Depth profiles taken above the plant's intake identified three sampling days at high risk for the contamination of the plant's raw water with potentially toxic cyanobacteria. Chlorophyceae and Bacillariophyceae caused false positive values to be generated by the phycocyanin probe when cyanobacteria represented a small fraction of the total phytoplanktonic biovolume present. However, there was little interference with the phycocyanin probe readings by other algal species when potential microcystin-producing cyanobacteria dominated the phytoplankton of the plant's untreated water. A two-tiered method for source water monitoring, using in vivo phycocyanin fluorescence, is proposed based on (1) a significant relationship between in vivo phycocyanin fluorescence and cyanobacterial biovolume and (2) the calculated maximum potential microcystin concentration produced by dominant Microcystis sp. biovolume. This method monitors locally-generated threshold values for cyanobacterial biovolume and microcystin concentrations using in vivo phycocyanin fluorescence.

  1. The complete mitochondrial DNA sequences of Nephroselmis olivacea and Pedinomonas minor. Two radically different evolutionary patterns within green algae.

    PubMed Central

    Turmel, M; Lemieux, C; Burger, G; Lang, B F; Otis, C; Plante, I; Gray, M W

    1999-01-01

    Green plants appear to comprise two sister lineages, Chlorophyta (classes Chlorophyceae, Ulvophyceae, Trebouxiophyceae, and Prasinophyceae) and Streptophyta (Charophyceae and Embryophyta, or land plants). To gain insight into the nature of the ancestral green plant mitochondrial genome, we have sequenced the mitochondrial DNAs (mtDNAs) of Nephroselmis olivacea and Pedinomonas minor. These two green algae are presumptive members of the Prasinophyceae. This class is thought to include descendants of the earliest diverging green algae. We find that Nephroselmis and Pedinomonas mtDNAs differ markedly in size, gene content, and gene organization. Of the green algal mtDNAs sequenced so far, that of Nephroselmis (45,223 bp) is the most ancestral (minimally diverged) and occupies the phylogenetically most basal position within the Chlorophyta. Its repertoire of 69 genes closely resembles that in the mtDNA of Prototheca wickerhamii, a later diverging trebouxiophycean green alga. Three of the Nephroselmis genes (nad10, rpl14, and rnpB) have not been identified in previously sequenced mtDNAs of green algae and land plants. In contrast, the 25,137-bp Pedinomonas mtDNA contains only 22 genes and retains few recognizably ancestral features. In several respects, including gene content and rate of sequence divergence, Pedinomonas mtDNA resembles the reduced mtDNAs of chlamydomonad algae, with which it is robustly affiliated in phylogenetic analyses. Our results confirm the existence of two radically different patterns of mitochondrial genome evolution within the green algae. PMID:10488238

  2. The mystery of clade X: Orciraptor gen. nov. and Viridiraptor gen. nov. are highly specialised, algivorous amoeboflagellates (Glissomonadida, Cercozoa).

    PubMed

    Hess, Sebastian; Melkonian, Michael

    2013-09-01

    In freshwater ecosystems a vast diversity of elusive protists exists that specifically feed on microalgae. Due to difficulties in isolation and long-term maintenance, most of these are still poorly known. In this study stable, bacteria-free cultures of several limnetic, algivorous amoeboflagellates were investigated by light microscopy and molecular phylogenetic analyses. All strains represent naked, biflagellate cells, either occurring as rigid flagellates or as surface-attached amoebae. They perforate cell walls of certain Zygnematophyceae and Chlorophyceae (Viridiplantae) and phagocytose algal cell contents. Time-lapse microscopy revealed the feeding behaviour, locomotional processes and life histories of the amoeboflagellates. Clear differences in cell morphology and food range specificity led to the description of two new, monotypic genera Orciraptor and Viridiraptor, which occupy similar, but distinct ecological niches in aquatic ecosystems as 'necrophytophagous' and 'parasitoid' protists, respectively. Molecular phylogenetic analyses based on 18S rDNA sequence data demonstrated that Orciraptor and Viridiraptor belonged to 'clade X' within the order Glissomonadida (Cercozoa, Rhizaria). In conclusion, we established the phenotypic identity of a clade, which until now was exclusively known from environmental sequences, and erect the new family Viridiraptoridae for 'clade X'. Its algivorous members are compared with other glissomonads and nomenclatural, methodological and ecological aspects of these novel 'raptorial' amoeboflagellates are discussed.

  3. Modulatory effect of the exudates released by the brown kelp Lessonia spicata on the toxicity of copper in early developmental stages of ecologically related organisms.

    PubMed

    Fellous, Alexandre; Andrade, Santiago; Vidal-Ramirez, Francisco; Calderón, Ricardo; Beltran, Jessica; Correa, Juan A

    2017-02-01

    Lessonia spicata is a key dominant species along the Pacific coast of South America, providing a habitat for many organisms. However, this role can be affected by abiotic stress, such as metals. To counteract the toxic effect, L. spicata, among other seaweeds, releases exudates that bind metals. In this study, tolerances to copper of organisms related to the kelp forest (spores of Ulva lactuca (Chlorophyceae) and L. spicata (Phaeophyceae) and Zoea I of Taliepus dentatus (Milne-Edwards, Crustacea)) were studied; then, exudates are assessed by their protective effect. Exudates increase the 48-h 50% effective concentration (EC50) of the germination of spores from 8 to 23 μg Cu L(-1) for U. lactuca and from 119 to 213 μg Cu L(-1) for L. spicata and the survival of the larvae Zoea I 48-h 50% of lethal concentration (LC50) from 144 to 249 μg Cu L(-1). Results indicated that exudates had a protective effect. Each species is specifically sensitive to copper. Crab larvae Zoea I were able to support higher doses, and exposure before hatching increased their tolerance.

  4. Vegetation cyclic shift in eutrophic lagoon. Assessment of dystrophic risk indices based on standing crop evaluations

    NASA Astrophysics Data System (ADS)

    Lenzi, Mauro; Renzi, Monia; Nesti, Ugo; Gennaro, Paola; Persia, Emma; Porrello, Salvatore

    2013-11-01

    Orbetello lagoon (Tuscany, Italy) is a meso-eutrophic, shallow-water ecosystem which has undergone cyclic shifts in macrophyte dominance since 1970. Field data on the total standing crops of Chlorophyceae and Rhodophyceae (from 1983 to 2011) and Angiospermae (seagrass; from 1998 to 2007), produced each year by the ecosystem, was acquired. A general lagoon environment quality score (decay level DL, categories 0-4) was attributed (a posteriori) for each annual dataset examined. Univariate and multivariate statistical analyses were used to relate total macrophyte standing crops of 29 years of monitoring to the general quality score. Two indices were proposed (Abundance of Macroalgae Index, AMI, and Abundance of Seagrass Index, ASI, the latter in two versions, ASI-1 and ASI-2) and tested against DL. The results showed that biomass data did not accurately describe general environmental quality of the lagoon ecosystem, whereas the indices gave a better fit. AMI showed the best performance, demonstrating that macroalga data was much more informative than seagrass data. Values of AMI over 4.0 were significantly associated with critical general quality scores (DL > 2).

  5. River discharge as a major driving force on spatial and temporal variations in zooplankton biomass and community structure in the Godavari estuary India.

    PubMed

    Venkataramana, V; Sarma, V V S S; Matta Reddy, Alavala

    2017-08-28

    Variability in horizontal zooplankton biomass distribution was investigated over 13 months in the Godavari estuary, along with physical (river discharge, temperature, salinity), chemical (nutrients, particulate organic matter), biological (phytoplankton biomass), and geological (suspended matter) properties to examine the influencing factors on their spatial and temporal variabilities. The entire estuary was filled with freshwater during peak discharge period and salinity near zero, increased to ~ 34 psu during dry period with relatively high nutrient levels during former than the latter period. Due to low flushing time (< 1 day) and high suspended load (> 500 mg L(-1)) during peak discharge period, picoplankton (cyanophyceae) contributed significantly to the phytoplankton biomass (Chl-a) whereas microplankton and nanoplankton (bacillariophyceae, and chlorophyceae) during moderate and mostly microplankton during dry period. Zooplankton biomass was the lowest during peak discharge period and increased during moderate followed by dry period. The zooplankton abundance was controlled by dead organic matter during peak discharge period, while both phytoplankton biomass and dead organic matter during moderate discharge and mostly phytoplankton biomass during dry period. This study suggests that significant modification of physico-chemical properties by river discharge led to changes in phytoplankton composition and dead organic matter concentrations that alters biomass, abundance, and composition of zooplankton in the Godavari estuary.

  6. Zooplankton Distribution Related to Environmental Factors and Phytoplankton in a Shallow Tropical Lake (Lake Guiers, Senegal, West Africa)

    NASA Astrophysics Data System (ADS)

    Kâ, Samba; Pagano, Marc; Bâ, Nganssoumana; Bouvy, Marc; Leboulanger, Christophe; Arfi, Robert; Thiaw, Omar T.; Ndour, El Hadji M.; Corbin, Daniel; Defaye, Danielle; Cuoc, Corinne; Kouassi, Ernest

    2006-10-01

    The chemical and biological characteristics of Lake Guiers (Senegal) have changed markedly since the impoundment of the Senegal River (Diama and Manantali dams) and subsequent development of irrigated agriculture in the nineteen eighties. On a longitudinal transect of 10 stations (from south to north), the environmental characteristics and the spatial variability of physicochemical variables, phytoplankton and zooplankton communities were studied. Within a marked south-north gradient, the southern stations were characterized by the highest conductivity and pH and by the lowest values of suspended solids, chlorophyll-a concentrations and phytoplankton abundance (mainly Chlorophycea, Cyanobacteria and Bacillariophycea). The spatial distribution of zooplankton showed a clear distinction between the southern zone, characterized by the presence of the rotifers Brachionus falcatus and Conochiloides sp., the cladoceran Bosmina longirostris, the cyclopoid Thermocyclops neglectus and the calanoid Pseudodiaptomus hessei. A co-inertia analysis clearly showed that environmental factors and phytoplankton drives the spatial distribution of zooplankton communities. The comparison of our data with previous studies suggests a marked change in the biological communities since the impoundment of the Senegal River, with rarefaction of P. hessei and proliferation of the cyclopoid Mesocyclops ogunnus. Several hypotheses are discussed to explain these biological changes.

  7. Cultivation of freshwater microalgae in biodiesel wash water.

    PubMed

    Sassi, Patrícia Giulianna Petraglia; Calixto, Clediana Dantas; da Silva Santana, Jordana Kaline; Sassi, Roberto; Costa Sassi, Cristiane Francisca; Abrahão, Raphael

    2017-06-21

    Biodiesel wash water is a contaminating industrial effluent that must be treated prior to disposal. The use of this effluent as a low-cost alternative cultivation medium for microalgae could represent a viable supplementary treatment. We cultivated 11 microalgae species with potential use for biodiesel production to assess their growth capacities in biodiesel industrial washing waters. Only Monoraphidium contortum, Ankistrodesmus sp., Chlorococcum sp., and one unidentified Chlorophyceae species grew effectively in that effluent. M. contortum showed the highest growth capacity and had the second highest fatty acid content (267.9 mg g(-1) of DW), predominantly producing palmitic (20.9%), 7,10,13-hexadecatrienoic (14%), oleic (16.2%), linoleic (10.5%), and linolenic acids (23.2%). In the second phase of the experiment, the microalgae were cultivated in biodiesel wash water at 75% of its initial concentration as well as in WC (control) medium. After 21 days of cultivation, 25.8 and 7.2% of the effluent nitrate and phosphate were removed, respectively, and the chemical oxygen demand was diminished by 31.2%. These results suggest the possibility of cultivating biodiesel producing microalgae in industrial wash water effluents.

  8. Soil surface colonization by phototrophic indigenous organisms, in two contrasted soils treated by formulated maize herbicide mixtures.

    PubMed

    Joly, Pierre; Misson, Benjamin; Perrière, Fanny; Bonnemoy, Frédérique; Joly, Muriel; Donnadieu-Bernard, Florence; Aguer, Jean-Pierre; Bohatier, Jacques; Mallet, Clarisse

    2014-11-01

    Soil phototrophic microorganisms, contributors to soil health and food webs, share their particular metabolism with plants. Current agricultural practices employ mixtures of pesticides to ensure the crops yields and can potentially impair these non-target organisms. However despite this environmental reality, studies dealing the susceptibility of phototrophic microorganisms to pesticide mixtures are scarce. We designed a 3 months microcosm study to assess the ecotoxicity of realistic herbicide mixtures of formulated S-metolachlor (Dual Gold Safeneur(®)), mesotrione (Callisto(®)) and nicosulfuron (Milagro(®)) on phototrophic communities of two soils (Limagne vertisol and Versailles luvisol). The soils presented different colonizing communities, with diatoms and chlorophyceae dominating communities in Limagne soil and cyanobacteria and bryophyta communities in Versailles soil. The results highlighted the strong impairment of Dual Gold Safeneur(®) treated microcosms on the biomass and the composition of both soil phototrophic communities, with no resilience after a delay of 3 months. This study also excluded any significant mixture effect on these organisms for Callisto(®) and Milagro(®) herbicides. We strongly recommend carrying on extensive soil studies on S-metolachlor and its commercial formulations, in order to reconsider its use from an ecotoxicological point of view.

  9. Rapid Accumulation of Total Lipid in Rhizoclonium africanum Kutzing as Biodiesel Feedstock under Nutrient Limitations and the Associated Changes at Cellular Level.

    PubMed

    Satpati, Gour Gopal; Kanjilal, Sanjit; Narayana Prasad, Rachapudi Badari; Pal, Ruma

    2015-01-01

    Increase of total lipid and the proportion of the favorable fatty acids in marine green filamentous macroalga Rhizoclonium africanum (Chlorophyceae) was studied under nitrate and phosphate limitations. These stresses were given by both eliminating and doubling the required amounts of nitrate and phosphate salts in the growth media. A significant twofold increase in total lipid (193.03 mg/g) was achieved in cells in absence of nitrate in the culture medium, followed by phosphate limitation (142.65 mg/g). The intracellular accumulation of neutral lipids was observed by fluorescence microscopy. The scanning electron microscopic study showed the major structural changes under nutrient starvation. Fourier transform infrared spectroscopy (FTIR) revealed the presence of ester (C-O-C stretching), ketone (C-C stretching), carboxylic acid (O-H bending), phosphine (P-H stretching), aromatic (C-H stretching and bending), and alcohol (O-H stretching and bending) groups in the treated cells indicating the high accumulation of lipid hydrocarbons in the treated cells. Elevated levels of fatty acids favorable for biodiesel production, that is, C16:0, C16:1, C18:1, and C20:1, were identified under nitrate- and phosphate-deficient conditions. This study shows that the manipulation of cultural conditions could affect the biosynthetic pathways leading to increased lipid production while increasing the proportion of fatty acids suitable for biodiesel production.

  10. Description of Hyalodiscus flabellus sp. nov. (Vampyrellida, Rhizaria) and Identification of its Bacterial Endosymbiont, "Candidatus Megaira polyxenophila" (Rickettsiales, Alphaproteobacteria).

    PubMed

    Hess, Sebastian

    2017-02-01

    The genus Hyalodiscus Hertwig and Lesser, 1874 comprises naked freshwater amoebae with a unique set of characters, namely a vibrant orange-red colour, a discoid or fan-shaped morphology, and a characteristic rolling locomotion. Some species feed on the chloroplasts of green algae and were regarded as relatives of Vampyrella Cienkowski, 1865. However, because of striking morphological differences and the lack of molecular data, the exact relationship of Hyalodiscus to vampyrellids is still obscure. Here, I describe Hyalodiscus flabellus sp. nov., a bright orange, fan-shaped amoeba feeding on Oedogonium (Chlorophyceae), which likely is a close relative of the type species H. rubicundus Hertwig and Lesser, 1874. Sequence comparisons of the SSU rRNA gene revealed that H. flabellus belongs to a deep-branching, so far uncharacterised lineage of the order Vampyrellida (Rhizaria), here defined as family Hyalodiscidae POCHE, 1913. Based on these results, the systematic position of the genus Hyalodiscus could be finally clarified, accompanied by the revision of relevant diagnoses and a taxonomic summary. Furthermore, the work reports on endosymbiotic bacteria inhabiting the cytoplasm of H. flabellus, which were identified as "Candidatus Megaira polyxenophila" (Rickettsiales, Alphaproteobacteria) using the full cycle rRNA approach with newly designed FISH probes for this widespread endosymbiotic bacterium.

  11. Comparative sequence analysis of CP12, a small protein involved in the formation of a Calvin cycle complex in photosynthetic organisms.

    PubMed

    Groben, René; Kaloudas, Dimitrios; Raines, Christine A; Offmann, Bernard; Maberly, Stephen C; Gontero, Brigitte

    2010-03-01

    CP12, a small intrinsically unstructured protein, plays an important role in the regulation of the Calvin cycle by forming a complex with phosphoribulokinase (PRK) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). An extensive search in databases revealed 129 protein sequences from, higher plants, mosses and liverworts, different groups of eukaryotic algae and cyanobacteria. CP12 was identified throughout the Plantae, apart from in the Prasinophyceae. Within the Chromalveolata, two putative CP12 proteins have been found in the genomes of the diatom Thalassiosira pseudonana and the haptophyte Emiliania huxleyi, but specific searches in further chromalveolate genomes or EST datasets did not reveal any CP12 sequences in other Prymnesiophyceae, Dinophyceae or Pelagophyceae. A species from the Euglenophyceae within the Excavata also appeared to lack CP12. Phylogenetic analysis showed a clear separation into a number of higher taxonomic clades and among different forms of CP12 in higher plants. Cyanobacteria, Chlorophyceae, Rhodophyta and Glaucophyceae, Bryophyta, and the CP12-3 forms in higher plants all form separate clades. The degree of disorder of CP12 was higher in higher plants than in the eukaryotic algae and cyanobacteria apart from the green algal class Mesostigmatophyceae, which is ancestral to the streptophytes. This suggests that CP12 has evolved to become more flexible and possibly take on more general roles. Different features of the CP12 sequences in the different taxonomic groups and their potential functions and interactions in the Calvin cycle are discussed.

  12. Proximate Content of “Klekap” (Microphytobenthos and Their Associated Meiofauna) from Milk-Fish Pond

    NASA Astrophysics Data System (ADS)

    Widianingsih; Zainuri, Muhammad; Anggoro, Sutrisno; Pancasakti Kusumaningrum, Hermin

    2017-02-01

    Microphytobentos and their associated mieofauna (‘klekap”) have important role in milkfish pond ecosystem expecially traditional fish pond. Microphytobenthos and their associated meiofauna not only consists of unicellular microalgae from class Bacillariophyceae, Cyanophyceae, Chlorophyceae but also a lot of meiofauna such as Nematoda, Annelida, Mollusc, Arthropoda, etc. Microphytobenthos and their associated meiofauna inhabit in the upper most surface sediment layer. They also have important role in the primary and secondary productivity. This research has purpose to investigate the composition of proximate in the microphytobenthos and their associated meiofauna. Microphytobenthos and their associated meiofauna were taken from three milkfish ponds in Pati area, Central of Jawa, Indonesia. Samples were taken directly by hand core from 3 stations with 3 replications. The research result showed that the value of protein content had range 6.9±0.33 - 7.73±0.37 %-dw, the value of carbohydrate content had range 10.44±1.2 - 12.59±0.15 %-dw, the value of lipid content had range 0.86±0.07 - 0.96±0.07 %-dw. It concluded that the third station has higher value of protein, lipid and carbohydrate compared than the first and the second station.

  13. Response of phytoplankton community to low-dose atrazine exposure combined with phosphorus fluctuations.

    PubMed

    Pannard, Alexandrine; Le Rouzic, Bertrand; Binet, Françoise

    2009-07-01

    The effects of atrazine on a controlled phytoplankton community derived from a natural freshwater wetland exposed to low doses of this photosynthesis-inhibiting herbicide were examined. The community was exposed for 7 weeks to doses of 0.1, 1, and 10 microg L(-1) atrazine, combined with changes in nutrient concentration, and the photosynthetic activity, biomass, and community structure were noted during the experiment. Responses of the phytoplankton community were examined in terms of photosynthetic activity, biomass, and community structure. Significant effects of atrazine on the phytoplankton assemblage, in terms of primary production and community structure, were highlighted, even at doses as low as 1 and 0.1 microg L(-1), when associated with phosphorus fluctuations. The most abundant Chlorophyceae decreased in concentration with increasing atrazine dose, whereas cyanobacteria were more tolerant to atrazine, particularly with increased nutrient supply. The subinhibitory doses of atrazine used in the present study confirmed the higher sensitivity of long-term exposure of multispecies assemblages under resource competition. Our study supports the emerging hypothesis that the increasing prevalence of cyanobacterial blooms in European aquatic systems may result from a combination of unbalanced nutrient enrichment and selective pressures from multiple toxicants.

  14. Eukaryotes in Arctic and Antarctic cyanobacterial mats.

    PubMed

    Jungblut, Anne D; Vincent, Warwick F; Lovejoy, Connie

    2012-11-01

    Cyanobacterial mats are commonly found in freshwater ecosystems throughout the polar regions. Most mats are multilayered three-dimensional structures with the filamentous cyanobacteria embedded in a gel-like matrix. Although early descriptions mentioned the presence of larger organisms including metazoans living in the mats, there have been few studies specifically focused on the microbial eukaryotes, which are often small cells with few morphological features suitable for identification by microscopy. Here, we applied 18S rRNA gene clone library analysis to identify eukaryotes in cyanobacterial mat communities from both the Antarctic and the extreme High Arctic. We identified 39 ribotypes at the level of 99% sequence similarity. These consisted of taxa within algal and other protist groups including Chlorophyceae, Prasinophyceae, Ulvophyceae, Trebouxiophyceae, Bacillariophyceae, Chrysophyceae, Ciliophora, and Cercozoa. Fungi were also recovered, as were 21 metazoan ribotypes. The eukaryotic taxa appeared habitat-specific with little overlap between lake, pond, and ice shelf communities. Some ribotypes were common to both Arctic and Antarctic mats, suggesting global dispersal of these taxa and similarity in the environmental filters acting on protist communities. Many of these eukaryotic taxa likely benefit from protected, nutrient-rich microhabitats within the cyanobacterial mat environment.

  15. Spatial and seasonal variability of pico-, nano- and microphytoplankton at the bottom seawater in the north coast of Sfax, Eastern Mediterranean Sea.

    PubMed

    Rekik, Amira; Denis, Michel; Maalej, Sami; Ayadi, Habib

    2015-10-01

    In the frame of the Taparura Project, we studied the distribution of pico-, nano- and microphytoplankton communities in relation to environmental variables at 18 stations sampled during four coastal cruises conducted between October 2009 and July 2010 at the bottom, on the north coast of Sfax (Tunisia, Eastern Mediterranean Sea). The restoration effect on coastal ultraphytoplankton (<10 μm) and microphytoplankton (<200 μm) was investigated using conventional flow cytometry and inverted microscopy. Flow cytometry analysis of ultraphytoplankton resolved six groups (Prochlorococcus, Synechococcus, nanoeukaryotes and three distinct subgroups within picoeukaryotes). In addition to these autotrophic groups, two unknown groups were characterised on the north coast. Picophytoplankton abundance shifted from a summer dominance of Synechococcus to a dominance of picoeukaryotes and Prochlorococcus during spring. Nanoeukaryotes were the most abundant in spring. Microphytoplankton was resolved into five groups, labelled Bacillariophyceae, Dinophyceae, Cyanobacteriae, Euglenophyceae and Chlorophyceae. A total of 90 microphytoplankton species were identified in all stations, with an overwhelming abundance of large diatoms, a typical trait of benthic communities (Coscinodiscus sp., Grammatophora sp., Navicula sp., Pleurosigma sp., Striatella unipunctata …). Results collected in this study are favouring a beneficial impact on the ecosystem of the Sfax north coast restoration achieved by the Taparura Project.

  16. Ecological studies on Al-Khadoud Spring, Al-Hassa, Saudi Arabia.

    PubMed

    Al-Kahtani, Mohammed A; Youssef, Ashraf M; Fathi, Adel A

    2007-11-15

    Al-Khadoud spring is one of the most important water resources in Al-Hassa Governorate, Saudi Arabia. However, much of its biotic information is still unknown. This study presented preliminary ecological information of this aquatic body. Regarding to macrophytes, a total of eight species were observed along the study sites. These species include two submerged aquatic plants (Potamogeton pectinatus L. and Ceratophyllum demersum L.). The common distributed species are Phragmites australis (Cav.) Trimex Steud and Cyperus rotundus (L.). On the other hand, a total of 20 algal genera were recorded with 7 genera of Chlorophyceae, 8 of Bacillariophyceae, 4 of Cyanophyceae and one of Euglenophyceae. The common phytoplankton occurred in all three investigated sites were Chlorella vulgaris, Mougeotia sp., Oscillatoria sp. and Actinastrum sp. Regarding to the biotic fauna, different forms of unicellular zooplankton such as Paramecium and Amoeba were recorded. Invertebrates such as freshwater insects and some freshwater snails were documented in the study sites including Melanodies tuberculata, Melanopsis praemorsa and Lymnaea auricularia. As regard to vertebrates, one species of fish, Aphanius dispar, dominate the spring basin and its extended channels.

  17. Copper-Induced Membrane Depolarizations Involve the Induction of Mosaic TRP Channels, Which Activate VDCC Leading to Calcium Increases in Ulva compressa

    PubMed Central

    Gómez, Melissa; González, Alberto; Sáez, Claudio A.; Moenne, Alejandra

    2016-01-01

    The marine macroalga Ulva compressa (Chlorophyceae) is a cosmopolitan species, tolerant to heavy metals, in particular to copper. U. compressa was cultivated with 10 μM copper for 12 h and membrane depolarization events were detected. First, seven depolarization events occurred at 4, 8, 12–13, 80, and 86 min, and at 5 and 9 h of copper exposure. Second, bathocuproine sulphonate, a specific copper-chelating compound, was added before incorporating copper to the culture medium. Copper-induced depolarizations were inhibited by bathocuproine at 4, 8, 12–13, 80, and 86 min, but not at 5 and 9 h, indicating that initial events are due to copper ions entry. Third, specific inhibitors of human TRPA1, C4, C5, M8, and V1corresponding to HC030031, ML204, SKF96363, M8B, and capsazepin, respectively, were used to analyze whether copper-induced depolarizations were due to activation of transient receptor potentials (TRPs). Inhibitor effects indicate that the seven depolarizations involved the activation of functional mosaic TRPs that displayed properties similar to human TRPA, C, M, and/or V. Finally, inhibition of copper-induced depolarizations using specific TRP inhibitors suppressed calcium increases at 2, 3, and 12 h due to activation of voltage-dependent calcium channels (VDCCs). Thus, copper induces seven depolarization events that involve activation of mosaic TRPs which, in turn, activates VDCC leading to calcium increases at 2, 3, and 12 h in U. compressa. PMID:27379106

  18. Temporal Succession of Ancient Phytoplankton Community in Qinghai Lake and Implication for Paleo-environmental Change

    PubMed Central

    Li, Gaoyuan; Dong, Hailiang; Hou, Weiguo; Wang, Shang; Jiang, Hongchen; Yang, Jian; Wu, Geng

    2016-01-01

    Tibetan lake sediments in NW China are sensitive recorders of climate change. However, many important plankton members do not leave any microscopic features in sedimentary records. Here we used ancient DNA preserved in Qinghai Lake sediments to reconstruct the temporal succession of plankton communities in the past 18,500 years. Our results showed that seven classes and sixteen genera of phytoplankton in the lake underwent major temporal changes, in correlation with known climatic events. Trebouxiophyceae and Eustigmatophyceae were predominant during the cold periods, whereas Chlorophyceae, Phaeophyceae, Xanthophyceae, Bacillariophyceae, and Cyanophyceae were abundant during the warm periods. The inferred changes in temperature, nutrients, precipitation, and salinity, as driven by the Westerlies and summer Monsoon strength, likely contributed to these observed temporal changes. Based on these correlations, we propose the phytoplankton index as a proxy to reconstruct the stadial versus interstadial climate change history in Qinghai Lake. This taxon-specific index is free of terrestrial contamination, sensitive to short-term climatic oscillations, and continuous in recording all climatic events in the lake. The validity of this index and its applicability to other lakes is demonstrated by its good correlations with multiple climate records of Qinghai Lake and another lake on the Tibetan Plateau, Kusai Lake. PMID:26805936

  19. Hormone profiles in microalgae: gibberellins and brassinosteroids.

    PubMed

    Stirk, W A; Bálint, P; Tarkowská, D; Novák, O; Strnad, M; Ördög, V; van Staden, J

    2013-09-01

    Endogenous gibberellins and brassinosteroids were quantified in 24 axenic microalgae strains from the Chlorophyceae, Trebouxiophyceae, Ulvophyceae and Charophyceae microalgae strains after 4 days in culture. This is the first report of endogenous gibberellins being successfully detected in microalgae. Between 18 and 20 gibberellins were quantified in all strains with concentrations ranging from 342.7 pg mg(-1) DW in Raphidocelis subcapitata MACC 317-4746.1 pg mg(-)(1) DW in Scotiellopsis terrestris MACC 44. Slower growing strains (S. terrestris MACC 44, Gyoerffyana humicola MACC 334, Nautococcus mamillatus MACC 716 and Chlorococcum ellipsoideum MACC 712) exhibited the highest gibberellin contents while lowest levels of gibberellins were found in faster growing strains (R. subcapitata MACC 317 and Coelastrum excentrica MACC 504). In all strains, the active gibberellin detected in the highest concentration was GA6, the predominant intermediates were GA15 and GA53 and the main biosynthetic end products were GA13 and GA51. Gibberellin profiles were similar in all strains except for the presence/absence of GA12 and GA12ald. To date this is the second report of endogenous brassinosteroids in microalgae. Brassinosteroids were detected in all 24 strains with concentrations ranging from 117.3 pg mg(-)(1) DW in R. subcapitata MACC 317-977.8 pg mg(-)(1) DW in Klebsormidium flaccidum MACC 692. Two brassinosteroids, brassinolide and castasterone were determined in all the strains. Generally, brassinolide occurred in higher concentrations than castasterone.

  20. Photosynthetic recovery following desiccation of desert green algae (Chlorophyta) and their aquatic relatives.

    PubMed

    Gray, Dennis W; Lewis, Louise A; Cardon, Zoe G

    2007-10-01

    Recent molecular data suggest that desert green algae have evolved from freshwater ancestors at least 14 times in three major classes (Chlorophyceae, Trebouxiophyceae and Charophyceae), offering a unique opportunity to study the adaptation of photosynthetic organisms to life on land in a comparative phylogenetic framework. We examined the photorecovery of phylogenetically matched desert and aquatic algae after desiccation in darkness and under illumination. Desert algae survived desiccation for at least 4 weeks when dried in darkness, and recovered high levels of photosynthetic quantum yield within 1 h of rehydration in darkness. However, when 4 weeks of desiccation was accompanied by illumination, three of six desert taxa lost their ability to recover quantum yield during rehydration in the dark. Aquatic algae, in contrast, recovered very little during dark rehydration following even just 24 h of desiccation. Re-illuminating rehydrated algae produced a nearly complete recovery of quantum yield in all desert and two of five aquatic taxa. These contrasts provide physiological evidence that desert green algae possess mechanisms for photosynthetic recovery after desiccation distinct from those in aquatic relatives, corroborating molecular evidence that they are not happenstance, short-term visitors from aquatic environments. Photosensitivity during desiccation among desert algae further suggests that they may reside in protected microsites within crusts, and species specificity of photosensitivity suggests that disturbances physically disrupting crusts could lead to shifts or losses of taxonomic diversity within these habitats.

  1. The evo-devo of multinucleate cells, tissues, and organisms, and an alternative route to multicellularity.

    PubMed

    Niklas, Karl J; Cobb, Edward D; Crawford, David R

    2013-01-01

    Multinucleate cells, tissues, or organisms occur in 60 families of land plants and in five otherwise diverse algal lineages (Rhodophyceae, Xanthophyceae, Chlorophyceae, Ulvophyceae, and Charophyceae). Inspection of a morphospace constructed out of eight developmental processes reveals a large number of possible variants of multinucleate cells and organisms that, with two exceptions, are represented by one or more plant species in one or more clades. Thus, most of these permutations of developmental processes exist in nature. Inspection of the morphospace also shows how the siphonous body plan (a multinucleate cell with the capacity for indeterminate growth in size) can theoretically serve as the direct progenitor of a multicellular organism by a process similar to segregative cell division observed in siphonocladean algae. Using molecular phylogenies of algal clades, different evolutionary scenarios are compared to see how the multicellular condition may have evolved from a multinucleate unicellular progenitor. We also show that the siphonous progenitor of a multicellular organism has previously passed through the alignment-of-fitness phase (in which genetic similarity among cells/nuclei minimizes internal genomic conflict) and the export-of-fitness phase (in which genetically similar cells/nuclei collaborate to achieve a reproductively integrated multicellular organism). All that is theoretically required is the evolutionary acquisition of the capacity to compartmentalize its cytoplasm.

  2. Organochlorines, mercury, and selenium in wintering shorebirds from Washington and California

    USGS Publications Warehouse

    Custer, T.W.; Meyers, J.P.

    1990-01-01

    Dunlins Caldris alpina, and black-bellied plovers, Pluvialis squatarola, were collected in Washington and California during the winter of 1984-85; long-billed dowitchers, Limnodromus scolopaceus, were collected in California. Pooled breast muscles (by species, location, and date) were analyzed for organochlorines and pooled livers for mercury and selenium. DDE was detected in all eight dunlin, three of five dowitcher, and two of nine plover muscle pools. Estimated DDE concentrations in dunlin carcasses at two sites in California were greater than 3 ppm wet wt, a dietary concentration associated with eggshell thinning and decreased reproductive success in raptors. Detectable concentrations of mercury and selenium were found in all liver pools. Selenium concentrations in plovers from two sites in Washington were elevated (26.9 and 29.9 ppm dry wt), but below concentrations shown to affect reproductive success in black-necked stilts, Himantopus mexicanus. Elevated mercury concentrations in livers of dunlin from Bodega Bay (18.9 ppm dry wt) and Salinas River (16.3 ppm dry wt), California were below levels associated with acute toxicity.

  3. Migration stopovers and the conservation of arctic-breeding Calidrine sandpipers

    USGS Publications Warehouse

    Skagen, Susan K.

    2006-01-01

    Long-distance migration, one of the most physically demanding events in the animal kingdom, is well developed in many species of Charadriidae and Scolopacidae. Some shorebirds renowned for their extraordinary long-distance migrations, notably American Golden-Plover (Pluvialis dominica), Red Knot (Calidris canutus rufa), and White-rumped Sandpiper (C. fuscicollis), travel as many as 15,000 km between southern South American wintering grounds and Canadian Arctic breeding areas. Migration strategies of shorebirds vary in many aspects. There are remarkable accounts of shorebirds, such as northbound Red Knots, that stage in a few key sites for 2–3 weeks and lay on extensive body stores, then fly nonstop for distances of ≤2,500 km (Harrington 2001, Piersma et al. 2005). Less well known are the examples of populations that refuel only briefly at stopover sites, disperse broadly on the landscape, and fly shorter distances between sites (Skagen 1997, Haig et al. 1998, Warnock et al. 1998). This latter pattern applies to many long-distance migrant shorebirds that cross the interior plains of North America during spring and fall migrations. For them, interior wetland complexes provide critical refueling resources along the direct routes between summering and wintering grounds (Skagen et al. 1999). In this issue of The Auk, Krapu et al. (2006) describe patterns and implications of fat deposition by Semipalmated Sandpipers (C. pusilla), White-rumped Sandpipers, and Baird's Sandpipers (C. bairdii) refueling during northward migration across the prairies of mid-continental North America.

  4. Persistent organochlorine levels in six prey species of the gyrfalcon Falco rusticolus in Iceland.

    PubMed

    Olafsdóttir, K; Petersen, A E; Magnúsdóttir, E V; Björnsson, T; Jóhannesson, T

    2001-01-01

    Our previous investigations have revealed very high levels of organochlorines (OCs) in the Icelandic gyrfalcon Falco rusticolus, a resident top predator. We now examine six potential prey species of birds, both resident and migratory, in order to elucidate the most likely route of the OCs to the gyrfalcon. The ptarmigan Lagopus mutus, the most important prey of the gyrfalcon, contained very low levels of OCs. Bioaccumulation of polychlorinated biphenyls (PCBs) and DDTs in mallards Anas platyrhynchos, tufted ducks Aythya fuligula, golden plovers Pluvialis apricaria, purple sandpipers Calidris maritima, and black guillemots Cepphus grylle reflected their position in the foodchain. The differences in OC-levels seem nevertheless too high just to reflect the different food-chain levels of these species in Iceland. The winter grounds of the migratory golden plovers and tufted ducks appear to be more contaminated than the Icelandic terrestrial habitat of ptarmigans or the freshwater habitat as reflected in mallards, both resident species. However, spending the winter on the coast in Iceland, results in high levels of contaminants in purple sandpipers and black guillemots. Our results indicate OC contamination of the marine ecosystem in Iceland while the terrestrial and freshwater ecosystems are little affected. It is postulated that gyrfalcons receive the major part of the observed contamination from prey other than ptarmigan, especially birds associated with the marine ecosystem and also from migratory birds.

  5. A review of the subfamily Picobiinae Johnston and Kethley, 1973 (Acariformes: Prostigmata: Syringophilidae).

    PubMed

    Skoracki, Maciej; Sikora, Bozena; Spicer, Greg S

    2016-05-19

    The fauna of quill mites of the subfamily Picobiinae Johnston and Kethley, 1973 (Acariformes: Cheyletoidea: Syringophilidae) is comprehensively revised. All of 78 known species, which are grouped into 11 genera, are examined and diagnosed or redescribed. Data on picobiine hosts and distribution are summarized, including new host and locality records. The following new species are described: Charadriineopicobia apricaria sp. nov. ex Pluvialis apricaria (Linnaeus) (Charadriiformes: Charadriidae) from France, Neopicobia pari sp. nov. ex Periparus venustulus Swinhoe (type host) (Passeriformes: Paridae) from China, Parus major Linnaeus (Paridae) from Macedonia and Finland, and Poecile varius Temminck and Schlegel (Paridae) from Japan, Picobia magellani sp. nov. ex Scytalopus magellanicus (Gmelin) (Passeriformes: Rhinocryptidae) from Colombia, Picobia lonchura sp. nov. ex Lonchura leucogastra (Blyth) (Passeriformes: Estrildidae) from Indonesia, Picobia makoli sp. nov. ex Xiphocolaptes promeropirhynchus (Lesson) (Passeriformes: Furnariidae) from Colombia. The species Picobia polonica Skoracki, Magowski and Dabert, 2001 syn. nov. is a junior synonym of C. khulkhaskhani Kivganov and Sharafat, 1995. The following new combinations are proposed: Neopicobia ictericus (Skoracki and Glowska, 2010) comb. nov., Rafapicobia brotogeris (Fain, Bochkov and Mironov, 2000) comb. nov., and Rafapicobia ramphastos (Fain, Bochkov and Mironov, 2000) comb. nov. Keys to the all picobiine genera and species are presented, along with a check-list of picobiine species and their hosts.

  6. Winter distributions of North American Plovers in the Laguna Madre regions of Tamaulipas, Mexico and Texas, USA

    USGS Publications Warehouse

    Mabee, Todd J.; Plissner, Jonathan H.; Haig, Susan M.; Goossen, J.P.

    2001-01-01

    To determine the distribution and abundance of wintering plovers in the Laguna Madre of Texas and Tamaulipas, surveys were conducted in December 1997 and February 1998, along a 160 km stretch of barrier islands in Mexico and- 40 km of shoreline on South Padre Island, Texas. Altogether, 5,673 individuals, representing six plover species, were recorded during the surveys. Black-bellied Plovers Pluvialis squatarola were the most numerous (3 ,013 individuals) representing 53% of the total number of plovers observed. Numbers of Piping Charadriusm elodu, Snowy C . alexandrinus, Semipalmated C. semipalmatus and Wilson's Plovers C. wilsonia were 739, 1,345, 561, and 13 birds, respectively. Most individuals (97%) of all species except Wilson's Plovers were observed on bayside flats of the barrier islands. Similar numbers of Piping Plovers were recorded at South Padre Island, Texas, and in the Laguna Madre de Tamaulipas. Over 85% of the individuals of each of the other species were found in the more extensively surveyed Mexico portion of Laguna Madre. In Tamaulipas, most plover species were observed more often on algal flats than any other substrate. These results provide evidence of the value of these systems as wintering areas for plover species and indicate the need for more extensive survey efforts to determine temporal and spatial variation in the distribution of these species within the Laguna ecosystem.

  7. Responses of Tabanidae (Diptera) to canopy traps baited with 4-methylphenol, 3-isopropylphenol, and naphthalene.

    PubMed

    Krcmar, Stjepan

    2007-12-01

    The attraction of female tabanids to unbaited and single-baited canopy traps using 4-methylphenol, 3-isopropylphenol, and naphthalene was studied in three forest localities in eastern Croatia. Tabanids were collected in a significantly higher number in traps baited with these chemicals compared to unbaited control traps. The number of females of Tabanus bromius, Tabanus sudeticus, Tabanus tergestinus, Hybomitra ciureai, Haematopota pluvialis, and Tabanus maculicornis collected from 4-methylphenol baited canopy traps and traps baited with other attractants differed significantly. A total of 89.0% of tabanids collected belonged to these six species. The response of the other species to used chemicals was not analyzed because of small sample sizes. Moreover, the results with 3-isopropylphenol and naphthalene are very similar and not significant for some tabanids. Tabanus bromius was the most abundant species with 48.4% in the sample collected by canopy traps. Finally, the 4-methylphenol baited canopy traps collected 16 times more tabanids than unbaited traps, while 3-isopropylphenol and naphthalene baited traps collected 3.5 and 2 times as many tabanids, respectively, than unbaited traps. Also, 4-methylphenol appeared to be a very effective attractant for Lucilia caesar (Calliphoridae), Sarcophaga carnaria (Sarcophagidae), and Musca domestica (Muscidae).

  8. Shorebird avoidance of nearshore feeding and roosting areas at night correlates with presence of a nocturnal avian predator

    USGS Publications Warehouse

    Piersma, Theunis; Gill, Robert E.; de Goeij, Petra; Dekinga, Anne; Shepherd, Marnie; Ruthrauff, Daniel R.; Tibbitts, T. Lee

    2006-01-01

    We here report two anecdotes about avianinteractions relevant to the interpretation of differences in shorebirdhabitat use between day and night. Several studies have reported that shorebirds avoid feeding and roosting along nearshore areasat night yet commonly use these sites during daytime. This suggests that nighttime avoidance of nearshore places is a response to increased danger of predation. When mist-netting during autumn 2005 on nearshore intertidal habitats along South Spit, Egegik Bay (Alaska Peninsula), Alaska, we discovered that shorebirds that occurred there in large numbers during daytime low tides and roosted there during daytime high tides (especially Dunlin Calidris alpina, Rock Sandpipers Calidris ptilocnemis, Black-bellied Plover Pluvialis squatarola, and Surfbirds Aphriza virgata), were absent at night. Their avoidance of the area correlated with Short-eared Owls Asio flammeus concurrently hunting over the beach and adjacent intertidal habitats. Spotlighting over nearby expansive intertidal mudflats confirmed that the same suite of species continued to forage or roost nearby at night. To bring the story full circle, the morning following one mist-netting effort we found a Short-eared Owl on the beach that had been killed earlier by a Gyrfalcon Falco rusticolus. In the owl’s stomach were remains of a freshly devoured Dunlin.

  9. Bloom forming species of phytoplankton in two coastal waters in the Southeast coast of India

    NASA Astrophysics Data System (ADS)

    Thillai Rajasekar, K.; Rajkumar, M.; Sun, Jun; Ashok Prabu, V.; Perumal, P.

    2010-09-01

    The results of an investigation carried out during June 2005 to May 2007 on bloom-forming phytoplankton species composition and abundance in the Parangipettai and Coleroon coastal waters (Southeast coast of India) are reported. Air and surface water temperatures (°C) varied from 25.1 to 30.1 and 24.5 to 28.5, respectively, in the former waters and from 25.5 to 31.2 and 25.0 to 29.3 in the latter waters. The respective salinities varied from 6.0 to 28.5 and 5.0 to 33.1 and the respective pH ranged between 7.0 and 8.3 and 7.2 and 8.3. Correspondingly, the dissolved oxygen content varied from 3.1 to 7.5 and 3.1 to 7.9 mgL-1 while the light extinction coefficient (LEC) values ranged between 3.1 and 10.1 and 1.8 and 11.0. The content ranges of inorganic nutrients, i.e., nitrate, nitrite, phosphate and silicate (μmolL-1), in the Parangipettai and Coleroon coastal waters were: 6.5-27.0; 1.0-8.9; 0.1-3.0 and 15.0-140 and 10.1-23.4; 1.2-8.9; 0.2-3.1 and 55-125 respectively. The chlorophyll a contents in both waters ranged from 2.0-7.5 μgL-1. Presently, 124 phytoplankton species representing different classes were recorded in the Coleroon coast, viz, Bacillariophyceae (77); Dinophyceae (19); Cyanophyceae (15); Chlorophyceae (10) and Chrysophyceae (3), whereas 117 phytoplankton species were recorded in the Parangipettai coast, viz, Bacillariophyceae (66); Dinophyceae (22); Cyanophyceae (19); Chlorophyceae (7) and Chrysophyceae (3). The phytoplankton cell abundance in the Parangipettai and Coleroon coastal waters varied from 290 to 111662 and 140 to 132 757 cells L-1, respectively, with peak diversity (3.38 and 3.52 bits ind-1.) recorded in summer. The maximum abundance occurred in summer coinciding with the stable hydrographical conditions. The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters. Totally 31 and 24 species of phytoplankton were found to be bloom-forming in the Parangipettai and Coleroon coastal waters

  10. Over-expression of Arabidopsis thaliana carotenoid hydroxylases individually and in combination with a beta-carotene ketolase provides insight into in vivo functions.

    PubMed

    Kim, Ji-Eun; Cheng, Kimberly M; Craft, Neal E; Hamberger, Björn; Douglas, Carl J

    2010-02-01

    Carotenoids represent a group of widely distributed pigments derived from the general isoprenoid biosynthetic pathway that possess diverse functions in plant primary and secondary metabolism. Modification of alpha- and beta-carotene backbones depends in part on ring hydroxylation. Two ferredoxin-dependent non-heme di-iron monooxygenases (AtB1 and AtB2) that mainly catalyze in vivo beta-carotene hydroxylations of beta,beta-carotenoids, and two heme-containing cytochrome P450 (CYP) monooxygenases (CYP97A3 and CYP97C1) that preferentially hydroxylate the epsilon-ring of alpha-carotene or the beta-ring of beta,epsilon-carotenoids, have been characterized in Arabidopsis by analysis of loss-of-function mutant phenotypes. We further investigated functional roles of both hydroxylase classes in modification of the beta- and epsilon-rings of alpha-carotene and beta-carotene through over-expression of AtB1, CYP97A3, CYP97C1, and the hydroxylase candidate CYP97B3. Since carotenoid hydroxylation is required for generation of ketocarotenoids by the bkt1(CrtO) beta-carotene ketolase, all hydroxylase constructs were also introduced into an Arabidopsis line expressing the Haematococcus pluvalis bkt1 beta-carotene ketolase. Analysis of foliar carotenoid profiles in lines overexpressing the individual hydroxylases indicate a role for CYP97B3 in carotenoid biosynthesis, confirm and extend previous findings of hydroxylase activities based on knock-out mutants, and suggest functions of the multifunctional enzymes in carotenoid biosynthesis. Hydroxylase over-expression in combination with bkt1 did not result in ketocarotenoid accumulation, but instead unexpected patterns of alpha-carotene derivatives, accompanied by a reduction of alpha-carotene, were observed. These data suggest possible interactions between the beta-carotene ketolase bkt1 and the hydroxylases that impact partitioning of carbon flux into different carotenoid branch pathways. 2009 Elsevier Ltd. All rights reserved.

  11. Developing a Phytoplankton Biotic Index as an Indicator of Freshwater Inflow within a Subtropical Estuary

    NASA Astrophysics Data System (ADS)

    Steichen, J. L.; Quigg, A.; Lucchese, A.; Preischel, H.

    2016-02-01

    Freshwater inflows drive the water and sediment quality in coastal bays and estuaries influencing the ecosystem and health of the biological community. Phytoplankton accessory pigments (used as a proxy for major taxonomic groups) have been utilized to develop a biotic index of physical, chemical and biotic disturbances in Chesapeake Bay (USA) and other estuarine systems. In this study we have used the Chesapeake Bay - Phytoplankton Index of Biotic Integrity model as a guide in developing an index for Galveston Bay, TX (USA) as an indicator of sufficient freshwater inflow to a subtropical estuary. Multivariate statistical analyses were run using PRIMER-E+PERMANOVA to determine the correlations between phytoplankton accessory pigment concentrations and a suite of abiotic factors associated with freshwater inflow (salinity, DIN, PO4, secchi). Phytoplankton pigment concentrations and water quality parameters were collected across Galveston Bay on a monthly basis from 2008-2013. In the upper region of the bay nearest the river source Dinophyceae, Cryptophyceae (winter (Dec-Feb)) and Chlorophyceae (winter and spring (Mar-May)) were significantly correlated to freshwater inflow and nutrient concentrations PO4 (p<0.05). Increased concentrations of Bacillariophyceae and Cyanophyceae (summer (Jun-Aug)) were significantly correlated to lower concentrations of DIN (p<0.05). Near the mouth of the estuary there was a significant correlation between the increase in Bacillariophyceae, Cyanophyceae, Cryptophyceae and Dinophyceae with decreasing PO4 (p<0.05). Within the dynamic system of Galveston Bay we are working to apply a Phytoplankton Index of Biotic Integrity as a means of monitoring the biological health of this ecologically and economically important estuarine ecosystem.

  12. Phytoplankton assemblages in a reservoir cascade of a large tropical - subtropical river (SE, Brazil).

    PubMed

    Nogueira, M G; Ferrareze, M; Moreira, M L; Gouvêa, R M

    2010-10-01

    The phytoplankton assemblages from eight reservoirs of the Paranapanema River were studied during two consecutive years. Chlorophyceae and Bacillaryophyceae dominated in richness. The observed high number of taxa, 234, reflects the extensive sampling programme and evidences the necessity of considering the whole hydrograph basin to assess the biodiversity status of inland water ecosystems. The dams had a negative effect on phytoplankton richness, with higher number of taxa associate to riverine (non-regulated) stretches. The tributary rivers also exhibited high species richness, showing the importance of considering the lateral dimension, in addition to the longitudinal one, for aquatic biota inventories in large river basins/reservoirs. Richness and diversity were also positively influenced by the connectivity with lateral wetlands (macrophyte-dominated lakes) due to the periphyton influence. The phytoplankton abundance/biomass was not influenced by higher water retention time. Higher values occurred in the middle basin stretches (river-passage reservoirs) due to the increase in the trophic conditions. There was a positive correlation with phosphorus. Poorer light conditions in the cascade do not limit the phytoplankton biomass, with assemblages dominated by species tolerant to turbulent conditions and high mineral turbidity. Bacillariophyceae and Cryptophyceae dominated numerically. The first group (unicellular forms) was prominent in the large and oligotrophic upstream reservoirs. The second was highly abundant in the river-passage (low retention time), and more eutrophic, reservoirs. Cyanophyceae growth is probably controlled by advection processes (wash-out effect). The zooplankton does not control the phytoplankton biomass and the diversity of both groups is positively associated in the cascade. The structure of the phytoplankton assemblages showed to be a good indicator of the operationally distinct reservoirs of the Paranapanema cascade and also reflected

  13. Seasonal patterns of water quality and phytoplankton dynamics in surface waters in Guangzhou and Foshan, China.

    PubMed

    Xu, Yanggui; Li, Adela Jing; Qin, Junhao; Li, Qi; Ho, Jonathan G; Li, Huashou

    2017-03-10

    During 2015, we studied the temporal patterns of nutrient concentrations and turbidity in water bodies with different degrees of agricultural and urban pressures across Guangzhou and Foshan (China). Data and observations were made by trained citizen scientists and professional researchers. Our study shows that all monitored water bodies, with the exception of Qiandeng Lake and Fengjiang River, had elevated NO3(-)-N concentrations, which ranged from 0.10 to 6.83mg/L and peaked in late winter and early spring and reached a minimum in summer and mid-autumn. PO43-P concentrations ranged from 0.01 to 0.25mg/L and peaked during the winter, late-summer and late autumn. Turbidity values were highest at sites with agricultural activities, with maximums in the late winter and autumn, and the highest frequency (16% and 25%) of algae presence occurred in the spring and autumn. To better understand the characteristics and drivers of the algae occurrences, measurements of phytoplankton composition and physicochemical characteristics were conducted in three key seasons in the agricultural process, fallow, sowing and rainy season in 2016. Our focused study found that the occurrence of Bacillariophyta, Euglenophyta, Xanthophyta, Cryptophyta, Chrysophyta were positively correlated with dissolved oxygen and phosphorus concentrations, while Chlorophyta and Cyanophyta had positive correlations with turbidity, oxygen demand and nitrogen concentrations. Bacillariophyceae counted for the highest proportion of phytoplankton during the fallow season, comprising up to 60+% of the phytoplankton among the sites. During the rainy season, Chlorophyceae species were the majority, comprising up to 90+% of phytoplankton among the sampled sites. Our results pointed to the complexity of nutrient and phytoplankton dynamics in water bodies under multiple pressures, and to the value of using citizen scientists to determine contextual information to benefit more focused studies.

  14. UV radiation-induced accumulation of photoprotective compounds in the green alga Tetraspora sp. CU2551.

    PubMed

    Rastogi, Rajesh P; Incharoensakdi, Aran

    2013-09-01

    The effect of UV radiation on the accumulation of novel mycosporine-like amino acids (MAAs) along with their photoprotective function was investigated in the green alga Tetraspora sp. CU2551. No UV-absorbing compound was detected in this organism growing under normal light condition while two MAAs with absorption maxima at 324 nm and 322 nm were found to be accumulated after UV irradiation. The effects of UV exposure time with different cut-off filter foils namely 295 (PAR + UV-A + UV-B), 320 (PAR + UV-A) and 395 nm (PAR only) were studied on induction of the synthesis of these MAAs. Concentration of MAAs was found to increase with increase in exposure time under UV radiation. Furthermore, the antioxidant and photoprotective action of these MAAs was also investigated. The role of MAAs in diminishing the UV-induced production of ROS in vivo was also demonstrated using the oxidant-sensing probe 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and results obtained supported the results of DPPH free radical scavenging assay. The MAAs also exhibited efficient photoprotective ability on Escherichia coli cells against UV-B stress. Thus, the MAAs in Tetraspora sp. CU2551 may act as efficient antioxidants as well as UV-sunscreen. This is the first report for the UV-induced synthesis and co-accumulation of these MAAs and their photoprotective actions in Tetraspora sp. which is a member of the class Chlorophyceae. Moreover, UV-induced accumulation as well as photoprotective function of these compounds may facilitate this chlorophyte to perform important ecological functions in harsh environmental conditions with high UV-B fluxes in their brightly lit habitats.

  15. Genetic diversity of planktonic eukaryotes in high mountain lakes (Central Pyrenees, Spain).

    PubMed

    Triadó-Margarit, Xavier; Casamayor, Emilio O

    2012-09-01

    The genetic diversity of planktonic eukaryotic microorganisms (size range 3-40 µm) inhabiting 11 alpine lakes of the Central Pyrenees (Spain) was analysed by cloning and sequencing of the 18S rRNA gene. The selected lakes covered a wide range of environmental conditions representative of the regional landscape heterogeneity. Overall, we obtained 953 sequences (averaged length 750 bp) that were grouped in 343 representative OTUs (98% identity). The genetic richness was high, and the 18S rRNA gene sequences spread within nine high-rank taxonomic groups and grouped in 26 eukaryal classes. Most of the sequences affiliated with Stramenopiles (> 55% of total sequences, mostly Chrysophyceae), Cryptophyta and Alveolata (15% each). Three groups had relative abundance < 5%, i.e. Opisthokonta (mostly Fungi), Viridiplantae (mostly Chlorophyceae) and Rhizaria (cercomonads). Finally, minor groups were related to Katablepharidophyta, Euglenozoa and Telonemida. The lakes showed a different community structure being pH, and phosphorous and Chl a concentrations the main environmental drivers. The novelty level was high, and a quarter of the retrieved OTUs were notably divergent (< 97% identity) from any previously known sequence, mainly for Rhizaria and Opisthokonta. More than 50% of the sequences affiliated with clusters exclusively formed by uncultured protists. Cryptophyta and Viridiplantae showed the largest number of sequences closely related to cultured counterparts. This work is the first description of the genetic diversity of eukaryotic assemblages in ultraoligotrophic high mountain lakes, and the study unveils alpine environments as an important reservoir of microbial eukaryotic biodiversity. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  16. Antioxidant, antimutagenic and antiproliferative activities in selected seaweed species from Sinaloa, Mexico.

    PubMed

    Osuna-Ruiz, Idalia; López-Saiz, Carmen-María; Burgos-Hernández, Armando; Velázquez, Carlos; Nieves-Soto, Mario; Hurtado-Oliva, Miguel A

    2016-10-01

    Context Seaweeds from the Mexican Pacific Ocean have not been evaluated as a source of chemoprotectants. Objective The objective of this study is to evaluate chemopreventive activities of the seaweeds Phaephyceae - Padina durvillaei (Dictyotaceae) - Rodhophyceae - Spyridia filamentosa (Spyridiaceae), Gracilaria vermiculophylla (Gracilariaceae) - and Chlorophyceae - Ulva expansa (Ulvaceae), Codium isabelae (Codiaceae), Rhizoclonium riparium (Cladophoraceae) and Caulerpa sertularioides (Caulerpaceae). Materials and methods Methanol, acetone and hexane seaweed extracts were assessed at 30 and 3 mg/mL on antioxidant capacity (DPPH and ABTS assays), 0.003-3.0 mg/plate on antimutagenic activity against AFB1 using Salmonella typhimurium TA98 and TA100 tester strains in Ames test, and 12.5 to 100 μg/mL on antiproliferative activity on Murine B-cell lymphoma. Phenols, flavonoids and pigments content were also assessed as antioxidant compounds. Results Extraction yield was higher in methanol than in acetone and hexane extracts (6.4, 2.7 and 1.4% dw). Antioxidant capacity was higher in brown and green than in red seaweed species, particularly in P. durvillaei extracted in acetone (EC50  value= 16.9 and 1.56 mg/mL for DPPH and ABTS). Flavonoids and chlorophylls were identified as mainly antioxidant components; particularly in hexane extracts, which were correlated with the antioxidant capacity. Highest mutagenesis inhibition (> 40%) occurred in R. riparium at the lowest concentration assayed (0.003 mg/plate), while highest antiproliferative inhibition (37 and 72% for 12.5 and 25 μg/mL) occurred in C. sertularioides. Discussion and conclusion Flavonoids and chlorophylls explained the chemopreventive activities assessed in S. filamentosa, R. riparium and C. sertularioides. These seaweeds have a high potential as a source of novel chemoprotectants.

  17. Hylodesmus singaporensis gen. et sp. nov., a new autosporic subaerial green alga (Scenedesmaceae, Chlorophyta) from Singapore.

    PubMed

    Eliás, Marek; Nemcová, Yvonne; Skaloud, Pavel; Neustupa, Jirí; Kaufnerová, Veronika; Sejnohová, Lenka

    2010-05-01

    The algal flora of subaerial habitats in the tropics remains largely unexplored, despite the fact that it potentially encompasses a wealth of new evolutionary diversity. Here we present a detailed morphological and molecular characterization of an autosporic coccoid green alga isolated from decaying wood in a natural forest in Singapore. Depending on culture conditions, this alga formed globular to irregularly oval solitary cells. Autosporulation was the only mode of reproduction observed. The cell periphery was filled with numerous vacuoles, and a single parietal chloroplast contained a conspicuous pyrenoid surrounded by a bipartite starch envelope. The cell wall was composed of a thick inner layer and a thin trilaminar outer layer, and the cell surface was ornamented with a few delicate ribs. Phylogenetic analyses of 18S rRNA gene sequences placed our strain in the family Scenedesmaceae (Sphaeropleales, Chlorophyceae) as a strongly supported sister branch of the genus Desmodesmus. Analyses of an alternative phylogenetic marker widely used for the Scenedesmaceae, the ITS2 region, confirmed that the strain is distinct from any scenedesmacean alga sequenced to date, but is related to the genus Desmodesmus, despite lacking the defining phenotypic features of Desmodesmus (cell wall with four sporopolleninic layers ornamented with peculiar submicroscopic structures). Collectively, our results establish that we identified a novel, previously undocumented, evolutionary lineage of scenedesmacean algae necessitating its description as a new species in a new genus. We propose it be named Hylodesmus singaporensis gen. et sp. nov. A cryopreserved holotype specimen has been deposited into the Culture Collection of Algae of Charles University in Prague, Czech Republic (CAUP) as CAUP C-H8001.

  18. Effects of dietary copper on life-history traits of a tropical freshwater cladoceran.

    PubMed

    Gusso-Choueri, P K; Choueri, R B; Lombardi, A T; Melão, M G G

    2012-05-01

    Life-history parameters of Ceriodaphnia cornuta (Cladocera: Daphniidae) fed on Pseudokirchneriella subcapitata (Chlorophyceae) exposed to different copper concentrations were investigated. C. cornuta individuals were reared in four treatments: (a) reconstituted water and non-contaminated algae (RW); (b) reconstituted water and copper-contaminated algae with either 1.28 × 10(-13) (10(-7)Cu) or (c) 1.93 × 10(-13) g Cu cell(-1) (10(-6)Cu); and (d) natural water from a local reservoir and non-contaminated algae (NW). Copper content in C. cornuta individuals increased as diet-borne exposure increased (RW < 10(-7)Cu < NW < 10(-6)Cu), except for NW individuals, which exhibited higher copper body burden than RW and 10(-7)Cu individuals, suggesting that some copper was available in the natural water. The results suggest that subacute levels of dietary copper stimulated C. cornuta's growth and reproduction, whereas organisms reared on reconstituted water showed nutritional deficiency. Depending on copper exposure concentration, either growth (lower Cu concentration) or reproduction (higher Cu concentration) was further stimulated, suggesting that an alteration of resource allocation is involved in diet-borne copper exposure. Because differences among treatments were only significantly different after day 12 of the experiment, our results reinforce that full life-cycle tests are more appropriate than the standard 7 day or three-brood chronic bioassays used to evaluate dietary copper effects at low, chronic copper inputs and that the use of standard test-organisms may not address site-specific situations for tropical environments.

  19. Microalgae Synthesize Hydrocarbons from Long-Chain Fatty Acids via a Light-Dependent Pathway1[OPEN

    PubMed Central

    Légeret, Bertrand; Mirabella, Boris; Guédeney, Geneviève; Jetter, Reinhard; Peltier, Gilles

    2016-01-01

    Microalgae are considered a promising platform for the production of lipid-based biofuels. While oil accumulation pathways are intensively researched, the possible existence of a microalgal pathways converting fatty acids into alka(e)nes has received little attention. Here, we provide evidence that such a pathway occurs in several microalgal species from the green and the red lineages. In Chlamydomonas reinhardtii (Chlorophyceae), a C17 alkene, n-heptadecene, was detected in the cell pellet and the headspace of liquid cultures. The Chlamydomonas alkene was identified as 7-heptadecene, an isomer likely formed by decarboxylation of cis-vaccenic acid. Accordingly, incubation of intact Chlamydomonas cells with per-deuterated D31-16:0 (palmitic) acid yielded D31-18:0 (stearic) acid, D29-18:1 (oleic and cis-vaccenic) acids, and D29-heptadecene. These findings showed that loss of the carboxyl group of a C18 monounsaturated fatty acid lead to heptadecene formation. Amount of 7-heptadecene varied with growth phase and temperature and was strictly dependent on light but was not affected by an inhibitor of photosystem II. Cell fractionation showed that approximately 80% of the alkene is localized in the chloroplast. Heptadecane, pentadecane, as well as 7- and 8-heptadecene were detected in Chlorella variabilis NC64A (Trebouxiophyceae) and several Nannochloropsis species (Eustigmatophyceae). In contrast, Ostreococcus tauri (Mamiellophyceae) and the diatom Phaeodactylum tricornutum produced C21 hexaene, without detectable C15-C19 hydrocarbons. Interestingly, no homologs of known hydrocarbon biosynthesis genes were found in the Nannochloropsis, Chlorella, or Chlamydomonas genomes. This work thus demonstrates that microalgae have the ability to convert C16 and C18 fatty acids into alka(e)nes by a new, light-dependent pathway. PMID:27288359

  20. Phytoplankton and bacterial community structures and their interaction during red-tide phenomena

    NASA Astrophysics Data System (ADS)

    Ismail, Mona Mohamed; Ibrahim, Hassan Abd Allah

    2017-07-01

    Phytoplankton and bacteria diversity were studied before, during and after red tide phenomena during spring season 2015 in the Eastern Harbour (E.H.) of Alexandria, Egypt. Fifty five species of phytoplankton were identified and represented different distinct classes "Bacillariophyceae; Dinophyceae, Chlorophyceae, Cyanophyceae and Eugelenophyceae". Also, Diatom formed the most dominant group. The average number of the phytoplankton density varied from 4.8 × 104 to 1.1 × 106 cell l-1 during the study period and Skeletonema costatum was the agent causing the red tide. The existence percentages of bacteria ranged from 2.6 to 17.9% on all media tested. The bacterial isolates on the nutrient agar medium represented the highest existence with a total percentage of 43.6%, followed by MSA medium (25.7%), while the lowest percentage was for the AA medium at 7.8%. However, twelve isolates were selected as representative for bacterial community during study interval. Based on the morphological, biochemical, physiological and enzymatic characteristics, the bacterial strains were described. Depending on the 16S rDNA gene sequence, three common antagonists were aligned as: Vibrio toranzoniae strain Vb 10.8, Ruegeria pelagia strain NBRC 102038 and Psychrobacter adeliensis strain DSM 15333. The interaction between these bacteria and S. costatum was studied. The growth of S. costatum was significantly lower whenever each bacterium was present as compared to axenic culture. More specifically, 30% (v/v) of the all tested bacteria showed the strongest algicidal activities, as all S. costatum cells were killed after two days. 10% of R. pelagia and P. adeliensis also showed significant algicidal activities within six days.

  1. High production of nitrous oxide (N2O), methane (CH4) and dimethylsulphoniopropionate (DMSP) in a massive marine phytoplankton culture

    NASA Astrophysics Data System (ADS)

    Florez-Leiva, L.; Tarifeño, E.; Cornejo, M.; Kiene, R.; Farías, L.

    2010-09-01

    The production of large amounts of algal biomass for different purposes such as aquaculture or biofuels, may cause impacts on the marine environment. One such impact is the production of radiatively active trace gases and aerosols with climate cooling (dimethyl sulfide DMS and its precursor DMSP) and warming (N2O and CH4) effects. Total and dissolved DMSP, N2O and CH4, together with other environmental variables were monitored daily for 46 days within a massive microalgae monoculture of Nannochloris (Chlorophyceae) in an open pond system. The growth of this green microalgae was stimulated by the addition of N- and P-rich salts, resulting in exponential growth (growth phase) during the first 17 days observed by cell abundance (1 × 106 to 4.4 × 106 cell mL-1) and Chl-a levels (from 1.4 to 96 mg Chl-a m-3) followed by a decrease in both Chl-a and cell abundance (senescence phase). Total DMSP (from 6.3 to 142 μmol m-3), dissolved DMSP i.e. 5.8 to 137 μmol m-3 and N2O (from 8 to 600 μmol m-3) abruptly peaked during the senescence phase, whereas CH4 steadily increased between 2 and 10 μmol m-3 during the growth phase. Different ratios between tracers and Chl-a during both phases reveal different biochemical processes involved in the cycling of these gases and tracers. Our results show that despite the consumption of large quantities of CO2 by the massive algal culture, a minor amount of DMS and huge amounts of greenhouse gases were produced, in particular N2O, which has a greater radiative effect per molecule than CO2. These findings have important implications for biogeochemical studies and for environmental management of aquaculture activities.

  2. Nutrient ratios and the complex structure of phytoplankton communities in a highly turbid estuary of Southeast Asia.

    PubMed

    Chu, Thuoc Van; Torréton, Jean-Pascal; Mari, Xavier; Nguyen, Huyen Minh Thi; Pham, Kha Thi; Pham, Thu The; Bouvier, Thierry; Bettarel, Yvan; Pringault, Olivier; Bouvier, Corinne; Rochelle-Newall, Emma

    2014-12-01

    Phytoplankton diversity and abundance in estuarine systems are controlled by many factors. Salinity, turbidity, and inorganic nutrient concentrations and their respective ratios have all been proposed as principal factors that structure phytoplankton diversity and influence the emergence of potentially toxic species. Although much work has been conducted on temperate estuaries, less is known about how phytoplankton diversity is controlled in tropical, monsoonal systems that are subject to large, seasonal shifts in hydrology and to rapidly changing land use. Here, we present the results of an investigation into the factors controlling phytoplankton species composition and distribution in a tropical, monsoonal estuary (Bach Dang estuary, North Vietnam). A total of 245 taxa, 89 genera from six algal divisions were observed. Bacillariophyceae were the most diverse group contributing to 51.4 % of the microalgal assemblage, followed by Dinophyceae (29.8 %), Chlorophyceae (10.2 %), Cyanophyceae (3.7 %), Euglenophyceae (3.7 %) and Dictyochophyceae (1.2 %). The phytoplankton community was structured by inorganic nutrient ratios (DSi:DIP and DIN:DIP) as well as by salinity and turbidity. Evidence of a decrease in phytoplankton diversity concomitant with an increase in abundance and dominance of certain species (e.g., Skeletonema costatum) and the appearance of some potentially toxic species over the last two decades was also found. These changes in phytoplankton diversity are probably due to a combination of land use change resulting in changes in nutrient ratios and concentrations and global change as both rainfall and temperature have increased over the last two decades. It is therefore probable in the future that phytoplankton diversity will continue to change, potentially favoring the emergence of toxic species in this system.

  3. Photosynthetic performance, lipid production and biomass composition in response to nitrogen limitation in marine microalgae.

    PubMed

    Jiang, Yuelu; Yoshida, Tomomi; Quigg, Antonietta

    2012-05-01

    Increasing energy prices demand a renewable, carbon neutral, transport fuel that is environmentally and commercially sustainable. The interest in the production of microalgae as biofuels is increasing due to their high oil content, rapid biomass production and small foot print. In this research, marine microalgae Dunaliella tertiolecta (Chlorophyceae) and Thalassiosira pseudonana (Bacillariophyceae) were incubated in nitrogen (N)-replete medium, and then transferred to N-free medium for 15 and 11 days, respectively. Fluorescence induction and relaxation (FIRe) fluorometry and Fourier transform infrared spectroscopy (FTIR) were used to monitor the photosynthetic performance, lipid production and metabolic responses to changing N availability. Growth rates of D. tertiolecta and T. pseudonana were 0.84 ± 0.16 d(-1) and 1.21 ± 0.09 d(-), respectively in N-replete medium. Upon transfer to N-free medium. The growth rates of T. pseudonana declined rapidly, while D. tertiolecta continued to grow for 5 days in N-free medium before growth declined slowly. The maximum quantum yield of photochemistry (F(v)/F(m)) remained high initially for D. tertiolecta but decreased immediately after transfer to N-free media for T. pseudonana. The functional absorption cross section for PSII (σ(PSII)) increased, the time constant for Q(A) reoxidation (τ(Qa)) and connectivity factor (p) decreased in parallel to the nutritional status of the microalgae. The relative protein and lipid content varied in response to N limitation, but carbohydrates did not change. Based on FTIR, D. tertiolecta and T. pseudonana produced 20-26% lipid when most stressed. The combination of photosynthetic efficiency and biomass composition monitoring provided evidence that metabolic strategies to changing nutrient status are species-specific. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  4. Trophic state of Foz de Almargem coastal lagoon (Algarve, South Portugal) based on the water quality and the phytoplankton community

    NASA Astrophysics Data System (ADS)

    Coelho, Susana; Gamito, Sofia; Pérez-Ruzafa, Angel

    2007-01-01

    Seasonal variation of water quality and phytoplankton community was studied in Foz de Almargem coastal lagoon in order to evaluate the trophic state of the wetland. This small coastal lagoon has temporary connections to the sea, when the sand barrier is naturally or artificially opened, but for most of the year is isolated receiving just the freshwater input from small rivers. Sampling took place in three stations along a gradient of marine influence from June 2001 to July 2002. During summer and autumn, the water in the lagoon was low, influencing positively water temperature, salinity, total solids in suspension (TSS), orthophosphates, total phosphorus (TP) and pH. In winter and spring, there was an increase of nitrates, nitrites, dissolved inorganic nitrogen (DIN) and N:P ratio with the raise of water level in the lagoon. Chlorophyll a and phaeo-pigments concentrations were positively related to the previous parameters. Phytoplankton density was low and switching in dominant taxa was observed along time but the community was mainly dominated by Dinophyceae and Bacillariophyceae. Chlorophyceae and Euglenophyceae were related to higher TSS and lower DIN, salinity and TP; Cyanophyceae were stimulated by the opposite conditions. The decrease of water level jointly with the raise of salinity and TP influenced positively pico-nano flagellate algae. Cryptophyceae were positively correlated with the same factors and also TSS. Several trophic state indexes and water quality indicators have been applied and an overall analysis pointed out to a coastal lagoon with mesotrophic characteristics. During the studied period no serious eutrophication events occurred, however there were some situations of nutrient enrichment due to human activities, such as agriculture and non-treated sewage discharges, which might have favoured the development of potentially toxic phytoplankton species, namely Prorocentrum minimum.

  5. A preliminary observation on water quality and plankton of an earthen fish pond in Bangladesh: recommendations for future studies.

    PubMed

    Hossain, Md Yeamin; Jasmine, Saleha; Ibrahim, Abu Hanif Md; Ahmed, Zoarder Faruque; Ohtomi, Jun; Fulanda, Bernerd; Begum, Momtaz; Mamun, Abdullahil; El-Kady, Mohamed A H; Wahab, Md Abdul

    2007-03-15

    The present study provides a characterization of water quality and plankton samples in earthen fish pond in Rajshahi, Bangladesh. Sampling was done over a period of six months, running from October, 2004 through March, 2005. All the water quality parameters were within the optimal ranges for plankton productivity. Temperatures varied from 19.75 to 27.25 degrees C; transparency, 24.75-29.50 cm; pH, 6.62-7.85; Dissolved Oxygen (DO), 3.87-5.85 mg L(-1); free CO2 5.25-7.25 mg L(-1) and bicarbonate (HCO3) alkalinity, 81.25-147.5 mg L(-1). Analyses of plankton samples recorded a total of 5 classes phytoplankton viz.; Bacillariophyceae, Chlorophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae and 2 classes of zooplankton; Crustacea and Rotifera. The phytoplankton population was comprised of 17 genera belonging to Cyanophyceae (5 classes, 34.47%), Bacillariophyceae (3, 13.87%), Cyanophyceae (3, 34.48%), Euglenophyceae (3, 10.68%) and 1 to Dinophyceae (6.50%). The zooplankton population consisted of 10 genera belonging to Rotifera (4, 40.13%) and Crustacea (6, 59.87%). Phytoplankton and zooplankton abundance varied from 60800 to 239400 units/l and 7620 to 12160 units/l, respectively. It is concluded that the phytoplankton groups provide the main support for earthen pond aquaculture in the pond compared to zooplankton classes. The information provides for more research to compare water quality and pond plankton characteristics in earthen aquaculture systems with and without fish stocking. Further studies on the seasonal changes of water quality parameters and its effects on plankton production in the fish ponds and all year extended monitoring is recommended in future studies.

  6. Essential role of conserved DUF177A protein in plastid 23S rRNA accumulation and plant embryogenesis

    PubMed Central

    Yang, Jiani; Suzuki, Masaharu; McCarty, Donald R.

    2016-01-01

    DUF177 proteins are nearly universally conserved in bacteria and plants except the Chlorophyceae algae. Thus far, duf177 mutants in bacteria have not established a function. In contrast, duf177a mutants have embryo lethal phenotypes in maize and Arabidopsis. In maize inbred W22, duf177a mutant embryos arrest at an early transition stage, whereas the block is suppressed in the B73 inbred background, conditioning an albino seedling phenotype. Background-dependent embryo lethal phenotypes are characteristic of maize plastid gene expression mutants. Consistent with the plastid gene expression hypothesis, quantitative real-time PCR revealed a significant reduction of 23S rRNA in an Escherichia coli duf177 knockout. Plastid 23S rRNA contents of duf177a mutant tissues were also markedly reduced compared with the wild-type, whereas plastid 16S, 5S, and 4.5S rRNA contents were less affected, indicating that DUF177 is specifically required for accumulation of prokaryote-type 23S rRNA. An AtDUF177A–green fluorescent protein (GFP) transgene controlled by the native AtDUF177A promoter fully complemented the Arabidopsis atduf177a mutant. Transient expression of AtDUF177A–GFP in Nicotiana benthamiana leaves showed that the protein was localized in chloroplasts. The essential role of DUF177A in chloroplast–ribosome formation is reminiscent of IOJAP, another highly conserved ribosome-associated protein, suggesting that key mechanisms controlling ribosome formation in plastids evolved from non-essential pathways for regulation of the prokaryotic ribosome. PMID:27574185

  7. Winter and spring phytoplankton composition and production in a shallow eutrophic Baltic lagoon

    NASA Astrophysics Data System (ADS)

    Schumann, R.; Hammer, A.; Görs, S.; Schubert, H.

    2005-01-01

    Taxonomic composition and productivity of winter and spring phytoplankton in a eutrophic estuary have been investigated in order to elucidate the carbon flux under conditions of limitation by physical factors - light and temperature. In spite of the important differences in nutrients, solar radiation and water temperature between winter and spring season, mean concentrations of particulate organic carbon were equal to 13.2 and 13.0 mgC l -1, respectively. Chlorophyll a averaged at 79 μgChl l -1 in winter, that is 69% of spring. Although community respiration accounted for only 6-26% of light saturated photosynthesis, integrated net primary production of the 1.2 m deep water column was negative until April. High attenuation of the water body ( Ko = 2.9 m -1) lead to a negative carbon balance (net heterotrophy) below 35 cm for all sampling dates. Thus, the high winter POC and phytoplankton values can only originate from summer or autumn primary production. This assumption was supported by a carbon loss rate of just 3% of total organic carbon per day for the whole water column. The composition of phytoplankton was very constant through both seasons: 39% Chlorophyceae, 33% Cyanobacteria and 25% Bacillariophyceae. As expected, phytoplankton was low light acclimated, having high α values (slope of light limited photosynthesis), but moderate maximum photosynthesis rates at saturating irradiances, which were heavily affected by temperature. Calculation of net carbon flux yet showed net heterotrophy of the Bodden waters in winter and early spring were caused by external physical limitation (low surface irradiance and low temperature) in combination with a high light attenuation of the water body.

  8. PredAlgo: a new subcellular localization prediction tool dedicated to green algae.

    PubMed

    Tardif, Marianne; Atteia, Ariane; Specht, Michael; Cogne, Guillaume; Rolland, Norbert; Brugière, Sabine; Hippler, Michael; Ferro, Myriam; Bruley, Christophe; Peltier, Gilles; Vallon, Olivier; Cournac, Laurent

    2012-12-01

    The unicellular green alga Chlamydomonas reinhardtii is a prime model for deciphering processes occurring in the intracellular compartments of the photosynthetic cell. Organelle-specific proteomic studies have started to delineate its various subproteomes, but sequence-based prediction software is necessary to assign proteins subcellular localizations at whole genome scale. Unfortunately, existing tools are oriented toward land plants and tend to mispredict the localization of nuclear-encoded algal proteins, predicting many chloroplast proteins as mitochondrion targeted. We thus developed a new tool called PredAlgo that predicts intracellular localization of those proteins to one of three intracellular compartments in green algae: the mitochondrion, the chloroplast, and the secretory pathway. At its core, a neural network, trained using carefully curated sets of C. reinhardtii proteins, divides the N-terminal sequence into overlapping 19-residue windows and scores the probability that they belong to a cleavable targeting sequence for one of the aforementioned organelles. A targeting prediction is then deduced for the protein, and a likely cleavage site is predicted based on the shape of the scoring function along the N-terminal sequence. When assessed on an independent benchmarking set of C. reinhardtii sequences, PredAlgo showed a highly improved discrimination capacity between chloroplast- and mitochondrion-localized proteins. Its predictions matched well the results of chloroplast proteomics studies. When tested on other green algae, it gave good results with Chlorophyceae and Trebouxiophyceae but tended to underpredict mitochondrial proteins in Prasinophyceae. Approximately 18% of the nuclear-encoded C. reinhardtii proteome was predicted to be targeted to the chloroplast and 15% to the mitochondrion.

  9. Influence of phosphorus on copper toxicity to Selenastrum gracile (Reinsch) Korshikov.

    PubMed

    Rocha, Giseli S; Lombardi, Ana T; Melão, Maria da Graça G

    2016-06-01

    Microalgae need a variety of nutrients for optimal growth and health. However, this rarely occurs in nature, and if nutrient proportions vary, biochemical changes can occur in phytoplankton community. This may result in modifications of zooplankton food quality, affecting aquatic food chains. Our aim was to investigate the toxicity of copper (Cu) to Selenastrum gracile, a common freshwater Chlorophyceae, at different physiological status induced by varying phosphorus (P) concentration in culture medium. Phosphorus was investigated at 2.3×10(-4), 1.1×10(-4), 2.3×10(-5), 4.6×10(-6) and 2.3×10(-6) mol L(-1) and Cu at six concentrations, ranging from 6.9×10(-9) mol L(-1) to 1.0×10(-7) mol L(-1) free Cu(2+) ions. To guarantee the cells would be in a physiological status that reflected the external P concentration, they were previously acclimated up to constant growth rate at each P concentration. Phosphorus acclimated cells were then exposed to Cu and toxicity was evaluated through population density, growth rates and chlorophyll a content. Free Cu(2+) ions concentrations were calculated through the chemical equilibrium model MINEQL(+). The results showed that higher Cu toxicity was obtained in P-limited than in P-replete cells, and that chlorophyll a/cell was higher in P-limited cells and excess Cu than in P-replete cells. This confirms the importance of microalgae nutritional status to withstand the negative effects of the trace metal. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Meiotic genes and sexual reproduction in the green algal class Trebouxiophyceae (Chlorophyta).

    PubMed

    Fučíková, Karolina; Pažoutová, Marie; Rindi, Fabio

    2015-06-01

    Sexual reproduction is widespread in eukaryotes and is well documented in chlorophytan green algae. In this lineage, however, the Trebouxiophyceae represent a striking exception: in contrast to its relatives Chlorophyceae and Ulvophyceae this group appears to be mostly asexual, as fertilization has been rarely observed. Assessments of sexual reproduction in the Trebouxiophyceae have been based on microscopic observation of gametes fusing. New genomic data offer now the opportunity to check for the presence of meiotic genes, which represent an indirect evidence of a sexual life cycle. Using genomic and transcriptomic data for 12 taxa spanning the phylogenetic breadth of the class, we tried to clarify whether genuine asexuality or cryptic sexuality is the most likely case for the numerous putatively asexual trebouxiophytes. On the basis of these data and a bibliographic review, we conclude that the view of trebouxiophytes as primarily asexual is incorrect. In contrast to the limited number of reports of fertilization, meiotic genes were found in all genomes and transcriptomes examined, even in species presumed asexual. In the taxa examined the totality or majority of the genes were present, Helicosporidium and Auxenochlorella being the only partial exceptions (only four genes present). The evidence of sex provided by the meiotic genes is phylogenetically widespread in the class and indicates that sexual reproduction is not associated with any particular morphological or ecological trait. On the basis of the results, we expect that the existence of the meiotic genes will be documented in all trebouxiophycean genomes that will become available in the future. © 2015 Phycological Society of America.

  11. Effects of dietborne cadmium on life history and secondary production of a tropical freshwater cladoceran.

    PubMed

    Souza, J P; Melo, D C; Lombardi, A T; Melão, M G G

    2014-11-01

    The presence of metals in aquatic environments has increased worldwide. Environmental assessments of metals in freshwater ecosystems presume that toxicity is mainly caused by aqueous exposure, but dietborne exposure (contaminated food) in zooplankton may occur because microalgae carry metal ions through adsorption/absorption of dissolved metal species, resulting in toxic effects once ingested by the animals. However, official regulations for ecotoxicological assays in most countries do not consider the toxic effects caused by dietborne exposure. Here, we provide life history parameters and secondary production of Simocephalus serrulatus (Koch 1841) (Cladocera: Daphniidae) fed with cadmium (Cd) contaminated algae during a 21-day bioassay. The microalgae Chlorophyceae Scenedesmus quadricauda was exposed for 96 h to dissolved Cd concentrations of 0.03; 5.87; 12.27 and 22.27 µg Cd l(-1) (equivalent to 1.6 × 10(-10); 3.2 × 10(-8); 6.7 × 10(-8); 1.2 × 10(-7) mol l(-1)) that resulted in algae internal Cd burdens of 0.004; 0.032; 0.270 and 0.280 pg Cd cell(-1), respectively. Significant toxic effects on life history parameters of S. serrulatus were observed. Time of embryonic development, generation time and age at first reproduction (primipara) showed significant delay. Length at first reproduction, number of eggs and clutches produced per female, hatching percentage, body length, survival and feeding rates were significantly reduced. Secondary production, that is, accumulated biomass for growth and reproduction, decreased significantly with dietborne Cd concentrations. Our results emphasize that food can be an important source of metals to zooplankton in aquatic ecosystems. Environmental regulations should consider the diet in ecotoxicological assessments. Furthermore, secondary production may be considered as a suitable endpoint in ecotoxicity tests.

  12. Variation of phytoplankton assemblages of Kongsfjorden in early autumn 2012: a microscopic and pigment ratio-based assessment.

    PubMed

    Bhaskar, Jane T; Tripathy, S C; Sabu, P; Laluraj, C M; Rajan, S

    2016-04-01

    Phytoplankton species distribution and composition were determined by using microscopy and pigment ratios in the Kongsfjorden during early autumn 2012. Variation in sea surface temperature (SST) was minimal and matched well with satellite-derived SST. Nutrients were generally limited. Surface phytoplankton abundance ranged from 0.21 × 10(3) to 10.28 × 10(3) cells L(-1). Phytoplankton abundance decreased with depth and did not show any significant correlation with chlorophyll a (chl a). Column-integrated phytoplankton cell counts (PCC) ranged from 94.3 × 10(6) cells m(-2) (Kf4) to 13.7 × 10(6) cells m(-2) (Kf5), while chl a was lowest at inner part of the fjord (6.3 mg m(-2)) and highest towards the mouth (24.83 mg m(-2)). Biomass from prymnesiophytes and raphidophytes dominated at surface and 10 m, respectively. The contribution of Bacillariophyceae to biomass was low. Generally, heterotrophic dinoflagellates were great in abundance (12.82 %) and ubiquitous in nature and were major contributors to biomass. Various chl pigments (chl b, chl c, phaeopigments (phaeo)) were measured to obtain pigment/chl a ratios to ascertain phytoplankton composition. Phaeo were observed only in inner fjord. Chl b:a ratios and microscopic observations indicated dominance of Chlorophyceae at greater depths than surface. Furthermore, microscopic observations confirmed dominance of chl c containing algae throughout the fjord. The study indicates that pigment ratios can be used as a tool for preliminary identification of major phytoplankton groups. However, under the presence of a large number of heterotrophic dinoflagellates such as Gymnodinium sp. and Gyrodinium sp., pigment signatures need to be supplemented by microscopic observations.

  13. Distinctive Architecture of the Chloroplast Genome in the Chlorodendrophycean Green Algae Scherffelia dubia and Tetraselmis sp. CCMP 881

    PubMed Central

    Turmel, Monique; de Cambiaire, Jean-Charles; Otis, Christian; Lemieux, Claude

    2016-01-01

    The Chlorodendrophyceae is a small class of green algae belonging to the core Chlorophyta, an assemblage that also comprises the Pedinophyceae, Trebouxiophyceae, Ulvophyceae and Chlorophyceae. Here we describe for the first time the chloroplast genomes of chlorodendrophycean algae (Scherffelia dubia, 137,161 bp; Tetraselmis sp. CCMP 881, 100,264 bp). Characterized by a very small single-copy (SSC) region devoid of any gene and an unusually large inverted repeat (IR), the quadripartite structures of the Scherffelia and Tetraselmis genomes are unique among all core chlorophytes examined thus far. The lack of genes in the SSC region is offset by the rich and atypical gene complement of the IR, which includes genes from the SSC and large single-copy regions of prasinophyte and streptophyte chloroplast genomes having retained an ancestral quadripartite structure. Remarkably, seven of the atypical IR-encoded genes have also been observed in the IRs of pedinophycean and trebouxiophycean chloroplast genomes, suggesting that they were already present in the IR of the common ancestor of all core chlorophytes. Considering that the relationships among the main lineages of the core Chlorophyta are still unresolved, we evaluated the impact of including the Chlorodendrophyceae in chloroplast phylogenomic analyses. The trees we inferred using data sets of 79 and 108 genes from 71 chlorophytes indicate that the Chlorodendrophyceae is a deep-diverging lineage of the core Chlorophyta, although the placement of this class relative to the Pedinophyceae remains ambiguous. Interestingly, some of our phylogenomic trees together with our comparative analysis of gene order data support the monophyly of the Trebouxiophyceae, thus offering further evidence that the previously observed affiliation between the Chlorellales and Pedinophyceae is the result of systematic errors in phylogenetic reconstruction. PMID:26849226

  14. The Bryopsis hypnoides Plastid Genome: Multimeric Forms and Complete Nucleotide Sequence

    PubMed Central

    Tian, Chao; Wang, Guangce; Niu, Jiangfeng; Pan, Guanghua; Hu, Songnian

    2011-01-01

    Background Bryopsis hypnoides Lamouroux is a siphonous green alga, and its extruded protoplasm can aggregate spontaneously in seawater and develop into mature individuals. The chloroplast of B. hypnoides is the biggest organelle in the cell and shows strong autonomy. To better understand this organelle, we sequenced and analyzed the chloroplast genome of this green alga. Principal Findings A total of 111 functional genes, including 69 potential protein-coding genes, 5 ribosomal RNA genes, and 37 tRNA genes were identified. The genome size (153,429 bp), arrangement, and inverted-repeat (IR)-lacking structure of the B. hypnoides chloroplast DNA (cpDNA) closely resembles that of Chlorella vulgaris. Furthermore, our cytogenomic investigations using pulsed-field gel electrophoresis (PFGE) and southern blotting methods showed that the B. hypnoides cpDNA had multimeric forms, including monomer, dimer, trimer, tetramer, and even higher multimers, which is similar to the higher order organization observed previously for higher plant cpDNA. The relative amounts of the four multimeric cpDNA forms were estimated to be about 1, 1/2, 1/4, and 1/8 based on molecular hybridization analysis. Phylogenetic analyses based on a concatenated alignment of chloroplast protein sequences suggested that B. hypnoides is sister to all Chlorophyceae and this placement received moderate support. Conclusion All of the results suggest that the autonomy of the chloroplasts of B. hypnoides has little to do with the size and gene content of the cpDNA, and the IR-lacking structure of the chloroplasts indirectly demonstrated that the multimeric molecules might result from the random cleavage and fusion of replication intermediates instead of recombinational events. PMID:21339817

  15. Distinctive Architecture of the Chloroplast Genome in the Chlorodendrophycean Green Algae Scherffelia dubia and Tetraselmis sp. CCMP 881.

    PubMed

    Turmel, Monique; de Cambiaire, Jean-Charles; Otis, Christian; Lemieux, Claude

    2016-01-01

    The Chlorodendrophyceae is a small class of green algae belonging to the core Chlorophyta, an assemblage that also comprises the Pedinophyceae, Trebouxiophyceae, Ulvophyceae and Chlorophyceae. Here we describe for the first time the chloroplast genomes of chlorodendrophycean algae (Scherffelia dubia, 137,161 bp; Tetraselmis sp. CCMP 881, 100,264 bp). Characterized by a very small single-copy (SSC) region devoid of any gene and an unusually large inverted repeat (IR), the quadripartite structures of the Scherffelia and Tetraselmis genomes are unique among all core chlorophytes examined thus far. The lack of genes in the SSC region is offset by the rich and atypical gene complement of the IR, which includes genes from the SSC and large single-copy regions of prasinophyte and streptophyte chloroplast genomes having retained an ancestral quadripartite structure. Remarkably, seven of the atypical IR-encoded genes have also been observed in the IRs of pedinophycean and trebouxiophycean chloroplast genomes, suggesting that they were already present in the IR of the common ancestor of all core chlorophytes. Considering that the relationships among the main lineages of the core Chlorophyta are still unresolved, we evaluated the impact of including the Chlorodendrophyceae in chloroplast phylogenomic analyses. The trees we inferred using data sets of 79 and 108 genes from 71 chlorophytes indicate that the Chlorodendrophyceae is a deep-diverging lineage of the core Chlorophyta, although the placement of this class relative to the Pedinophyceae remains ambiguous. Interestingly, some of our phylogenomic trees together with our comparative analysis of gene order data support the monophyly of the Trebouxiophyceae, thus offering further evidence that the previously observed affiliation between the Chlorellales and Pedinophyceae is the result of systematic errors in phylogenetic reconstruction.

  16. Evolutionary and Biotechnological Implications of Robust Hydrogenase Activity in Halophilic Strains of Tetraselmis

    PubMed Central

    D'Adamo, Sarah; Jinkerson, Robert E.; Boyd, Eric S.; Brown, Susan L.; Baxter, Bonnie K.; Peters, John W.; Posewitz, Matthew C.

    2014-01-01

    Although significant advances in H2 photoproduction have recently been realized in fresh water algae (e.g. Chlamydomonas reinhardtii), relatively few studies have focused on H2 production and hydrogenase adaptations in marine or halophilic algae. Salt water organisms likely offer several advantages for biotechnological H2 production due to the global abundance of salt water, decreased H2 and O2 solubility in saline and hypersaline systems, and the ability of extracellular NaCl levels to influence metabolism. We screened unialgal isolates obtained from hypersaline ecosystems in the southwest United States and identified two distinct halophilic strains of the genus Tetraselmis (GSL1 and QNM1) that exhibit both robust fermentative and photo H2-production activities. The influence of salinity (3.5%, 5.5% and 7.0% w/v NaCl) on H2 production was examined during anoxic acclimation, with the greatest in vivo H2-production rates observed at 7.0% NaCl. These Tetraselmis strains maintain robust hydrogenase activity even after 24 h of anoxic acclimation and show increased hydrogenase activity relative to C. reinhardtii after extended anoxia. Transcriptional analysis of Tetraselmis GSL1 enabled sequencing of the cDNA encoding the FeFe-hydrogenase structural enzyme (HYDA) and its maturation proteins (HYDE, HYDEF and HYDG). In contrast to freshwater Chlorophyceae, the halophilic Tetraselmis GSL1 strain likely encodes a single HYDA and two copies of HYDE, one of which is fused to HYDF. Phylogenetic analyses of HYDA and concatenated HYDA, HYDE, HYDF and HYDG in Tetraselmis GSL1 fill existing knowledge gaps in the evolution of algal hydrogenases and indicate that the algal hydrogenases sequenced to date are derived from a common ancestor. This is consistent with recent hypotheses that suggest fermentative metabolism in the majority of eukaryotes is derived from a common base set of enzymes that emerged early in eukaryotic evolution with subsequent losses in some organisms. PMID

  17. Long-term adaptive response to high-frequency light signals in the unicellular photosynthetic eukaryote Dunaliella salina.

    PubMed

    Combe, Charlotte; Hartmann, Philipp; Rabouille, Sophie; Talec, Amelie; Bernard, Olivier; Sciandra, Antoine

    2015-06-01

    Productivity of microalgal cultivation processes is tightly related to photosynthetic efficiency, and therefore to light availability at the cell scale. In an agitated, highly turbid suspension,the light signal received by a single phytoplankton cell moving in a dense culture is a succession of flashes. The growth characteristics of microalgae under such dynamic light conditions are thus fundamental information to understand nonlinear properties of the photosynthetic process and to improve cultivation process design and operation. Studies of the long term consequences of dynamic illumination regime on photosynthesis require a very specific experimental set-up where fast varying signals are applied on the long term. In order to investigate the growth response of the unicellular photosynthetic eukaryote Dunaliella salina (Chlorophyceae) to intermittent light exposure, different light regimes using LEDs with the same average total light dose were applied in continuous cultures. Flashing light with different durations of light flashes (△t of 30 s, 15 s, 2 s and 0.1 s) followed by dark periods of variable length (0.67 ≤ L:D ≤ 2) yielding flash frequencies in the range 0.017-5 Hz, were compared to continuous illumination. Specific growth rate, photosynthetic pigments, lipid productivity and elemental composition were measured on two duplicates for each irradiance condition. The different treatments of intermittent light led to specific growth rates ranging from 0.25 to 0.93 day(-1) . While photosynthetic efficiency was enhanced with increased flash frequency, no significant differences were observed in the particular carbon and chlorophyll content. Pigment analysis showed that within this range of flash frequency, cells progressively photoacclimated to the average light intensity.

  18. Seasonal distribution of phytoplankton and its association with physico-chemical parameters in coastal waters of Malvan, west coast of India.

    PubMed

    Hardikar, Revati; Haridevi, C K; Chowdhury, Mintu; Shinde, Namrata; Ram, Anirudh; Rokade, M A; Rakesh, P S

    2017-04-01

    Malvan coast is one of the Marine Protected Area (MPA) of Maharashtra because of its rich coral reef and biodiversity. The study investigated on phytoplankton assemblage and their diversity with respect to physico-chemical parameters covering protected and unprotected area of Malvan coast. Physico-chemical parameters such as salinity, nitrite, nitrate, and ammonia did not display seasonality due to inadequate fresh water influx and allochthonous nutrient input. Positive correlation of phosphate (r = 0.96, p < 0.0001) and silicate (r = 0.91, p < 0.0001) with Total Suspended Solids (TSS) confirmed their autochthonous origin as a result of resuspension of bottom sediments during monsoon. A total of 57 phytoplankton species were identified mostly dominated by Bascillariophyceae (40 species), followed by Dinophyceae (9 species), Chlorophyceae (5 species), Cyanophyceae (2 species), and Dictyochophyceae (1 species) from Malvan coast. Canonical correspondence analysis (CCA) revealed that water temperature and TSS were the most significant parameters influencing the distribution and seasonal shift in phytoplankton species such as Skeletonema costatum and Chaetoceros sp. during pre-monsoon and Psedo-nitzschia sp., Streptotheca thamensis, Eucampia zodiacus, and Lithodesmium undulatum during post-monsoon. Silicate and phosphate had minor influence on phytoplankton distribution. Shannon-Wiener diversity index as a pollution index suggested that the study area was incipiently polluted except at bay stations. Despite of various human interventions the water quality and phytoplankton assemblage of this area has not reached to an alarming situation. The current study provides a valuable baseline data on phytoplankton assemblage from Malvan coast.

  19. Exploring occurrence and molecular diversity of betaine lipids across taxonomy of marine microalgae.

    PubMed

    Cañavate, José Pedro; Armada, Isabel; Ríos, José Luis; Hachero-Cruzado, Ismael

    2016-04-01

    Betaine lipids (BL) from ten microalgae species of the kingdoms Plantae and Chromista were identified and quantified by HPLC/ESI-TOF-MS. Diacylgyceryl-N-trimethylhomoserine (DGTS) was detected in Trebouxiophyceae and Eustigmatophyceae species, whereas Tetraselmis suecica was described as the first green algae containing diacylglyceryl-hydroxymethyl-N,N,N-trimethyl-beta-alanine (DGTA). DGTA molecular species where also characterized in Cryptophyceae species as well as in the Bacillariophyceae diatom Phaeodactylum tricornutum. The Mediophyceae diatom Chaetoceros gracilis had no DGTA, but contained diacylglyceryl-carboxyhydroxymethylcholine (DGCC). A principal coordinate (PCO) analysis of microalgae species revealed the existence of three main clusters around each BL type. The first PCO axis (43.9% of total variation) grouped Chlorophyceae, Trebouxiophyceae and Eustigmatophyceae species and positively correlated with DGTS. The second PCO axis (27.8% of total variation) segregated DGTA from DGCC containing species. Cryptophyceae, Bacillariophyceae and Chlorodendrophyceae were the more closely associated species to DGTA. Mediophyceae and Dinophyceae species contained DGCC as the only BL. Molecular diversity varied from the simplest DGCC composition in Gyrodinium dorsum to the highest spectrum of ten different molecular species detected for DGTA (Rhodomonas baltica) and DGCC (C. gracilis). The fatty acid profile of DGTS was very dissimilar to that of the whole lipid cell content. DGTS from Nannochloropsis gaditana was highly unsaturated respecting to total lipids, whereas in Picochlorum atomus DGTS unsaturation was nearly one half to that of total lipids. Dissimilarity between DGTA and total lipid fatty acid profile was minimum among all BL and DGTA fatty acid unsaturation was the maximum observed in the study. New DGCC molecular species enriched in 20:5 were described in Mediophyceae diatoms. Multivariate microalgae ordination using BL as descriptors revealed a higher

  20. Atypical subunit composition of the chlorophycean mitochondrial F1FO-ATP synthase and role of Asa7 protein in stability and oligomycin resistance of the enzyme.

    PubMed

    Lapaille, Marie; Escobar-Ramírez, Adelma; Degand, Hervé; Baurain, Denis; Rodríguez-Salinas, Elizabeth; Coosemans, Nadine; Boutry, Marc; Gonzalez-Halphen, Diego; Remacle, Claire; Cardol, Pierre

    2010-07-01

    In yeast, mammals, and land plants, mitochondrial F(1)F(O)-ATP synthase (complex V) is a remarkable enzymatic machinery that comprises about 15 conserved subunits. Peculiar among eukaryotes, complex V from Chlamydomonadales algae (order of chlorophycean class) has an atypical subunit composition of its peripheral stator and dimerization module, with nine subunits of unknown evolutionary origin (Asa subunits). In vitro, this enzyme exhibits an increased stability of its dimeric form, and in vivo, Chlamydomonas reinhardtii cells are insensitive to oligomycins, which are potent inhibitors of proton translocation through the F(O) moiety. In this work, we showed that the atypical features of the Chlamydomonadales complex V enzyme are shared by the other chlorophycean orders. By biochemical and in silico analyses, we detected several atypical Asa subunits in Scenedesmus obliquus (Sphaeropleales) and Chlorococcum ellipsoideum (Chlorococcales). In contrast, complex V has a canonical subunit composition in other classes of Chlorophytes (Trebouxiophyceae, Prasinophyceae, and Ulvophyceae) as well as in Streptophytes (land plants), and in Rhodophytes (red algae). Growth, respiration, and ATP levels in Chlorophyceae were also barely affected by oligomycin concentrations that affect representatives of the other classes of Chlorophytes. We finally studied the function of the Asa7 atypical subunit by using RNA interference in C. reinhardtii. Although the loss of Asa7 subunit has no impact on cell bioenergetics or mitochondrial structures, it destabilizes in vitro the enzyme dimeric form and renders growth, respiration, and ATP level sensitive to oligomycins. Altogether, our results suggest that the loss of canonical components of the complex V stator happened at the root of chlorophycean lineage and was accompanied by the recruitment of novel polypeptides. Such a massive modification of complex V stator features might have conferred novel properties, including the stabilization of

  1. Seaweeds as bioindicators of heavy metals off a hot spot area on the Egyptian Mediterranean Coast during 2008-2010.

    PubMed

    Shams El-Din, N G; Mohamedein, L I; El-Moselhy, Kh M

    2014-09-01

    Concentrations of Cu, Zn, Cd, Pb, Ni, Co, Fe, Mn, and Hg were measured successively in water, sediments, and six macroalgal species belonging to three algal classes during 3 years (2008-2010) from Abu Qir Bay, Alexandria, Egypt: Chlorophyceae (Enteromorpha compressa, Ulva fasciata), Phaeophyceae (Padina boryana), and Rhodophyceae (Jania rubens, Hypnea musciformis, Pterocladia capillacea). The study aimed to assess the bioaccumulation potential of the seaweeds, as well as to evaluate the extent of heavy metal contamination in the selected study site. Metals were analyzed using atomic absorption spectrophotometry coupled with MH-10 hydride system. The obtained data showed that the highest mean concentrations of Cu, Zn, Fe, and Mn were recorded in E. compressa; Cd, Ni, and Hg exhibited their highest mean concentrations in P. boryana, while Pb and Co were found in J. rubens. Abundance of the heavy metals in the algal species was as follow: Fe > Mn > Zn > Pb > Ni > Co > Cu > Cd > Hg. E. compressa showed the maximum metal pollution index (MPI) which was 11.55. Bioconcentration factor (BCF) for the metals in algae was relatively high with a maximum value for Mn. The Tomlinson pollution load index (PLI) values for the recorded algal species were low, which ranged between 1.00 in P. boryana and 2.72 in E. compressa. Enrichment factors for sediments were low fluctuating between 0.43 for Hg to 2.33 for Mn. Accordingly, the green alga E. compressa, brown alga P. boryana, and red alga J. rubens can be nominated as bioindicators. Based on MPI and PLI indices, Abu Qir Bay in the present study is considered as low-contaminated area.

  2. Auxin and cytokinin relationships in 24 microalgal strains(1).

    PubMed

    Stirk, Wendy A; Ördög, Vince; Novák, Ondřej; Rolčík, Jakub; Strnad, Miroslav; Bálint, Péter; van Staden, Johannes

    2013-06-01

    Endogenous auxins and cytokinins were quantitated in 24 axenic microalgal strains from the Chlorophyceae, Trebouxiophyceae, Ulvophyceae, and Charophyceae. These strains were in an exponential growth phase, being harvested on day 4. Acutodesmus acuminatus Mosonmagyaróvár Algal Culture Collection-41 (MACC) produced the highest biomass and Chlorococcum ellipsoideum MACC-712 the lowest biomass. The auxins, indole-3-acetic acid (IAA) and indole-3-acetamide (IAM) were present in all microalgal strains. No other auxin conjugates were detected. IAA and IAM concentrations varied greatly, ranging from 0.50 to 71.49 nmol IAA · g(-1) DW and 0.18 to 99.83 nmol IAM · g(-1) DW, respectively. In 19 strains, IAA occurred in higher concentrations than IAM. Nineteen cytokinins were identified in the microalgal strains. Total cytokinin concentrations varied, ranging from 0.29 nmol · g(-1) DW in Klebsormidium flaccidum MACC-692 to 21.40 nmol · g(-1) DW in Stigeoclonium nanum MACC-790. The general trend was that cis-zeatin types were the predominant cytokinins; isopentenyladenine-type cytokinins were present in moderate concentrations, while low levels of trans-zeatin-type and very low levels of dihydrozeatin-type cytokinins were detected. Ribotides were generally the main cytokinin conjugate forms present with the cytokinin free bases and ribosides present in similar but moderate levels. The levels of O-glucosides were low. Only one N-glucoside was detected, being present in nine strains in very low concentrations. In 15 strains, the auxin content was 2- to 4-fold higher than the cytokinin content.

  3. Birds of the Kilbuck and Ahklun mountain region, Alaska

    USGS Publications Warehouse

    Petersen, Margaret R.; Weir, Douglas N.; Dick, Matthew H.

    1991-01-01

    Between 1952 and 1988, we studied the abundance, distribution, occurrence, and habitats used by birds in the northwest portion of Bristol Bay and the adjacent Kilbuck and Ahklun mountains. In the 809 days we were present, we conducted 53 studies or surveys of birds in the region. We gathered information on 185 species, of which 65% (121) nested, 10% (19) probably nested, and 11% (21) were permanent residents in the region. Most breeding or probably breeding forms were of North American (58%; 81) or Beringian (24%; 33) affinity, while the remainder of the species were of Panboreal (17%; 24) and Old World (1%; 2) affinity. Similarly, most of the 44 migrants and visitants were of North American (41%; 18) affinity, while the remainder were of Beringian (32%; 14) and Panboreal (27%; 12) affinity. Of the 140 species that nested or probably nested, 53% (73) were abundant to fairly common, 29% (40) were uncommon to very rare, and 20% (27) were localized. Shrub thicket, dwarf shrub mat, coniferous forest, deciduous forest, mixed deciduous-coniferous forest, and fluviatile water and shoreline habitats supported the greatest diversity of species breeding and suspected of breeding. The highest concentrations of birds occurred in the estuaries of Nanvak, Chagvan, and Goodnews bays during spring and fall migrations and on the coastal and island cliffs during the breeding season.The information presented here provides the basis for range extensions of several species. Our records further clarify the known or probable Alaska breeding ranges of 11 species (fork-tailed storm-petrel, Oceanodroma furcata; double-crested cormorant, Phalacrocorax auritus; red-faced cormorant, Phatacrocorax utile, brant, Branta bernicla; king eider, Somateria spectabilis; white-tailed ptarmigan, Lagopus leucurus; black-bellied plover, Pluvialis squatarola; Pacific golden-plover, Pluvialis fulva; lesser yellowlegs, Tringa flavipes; Say's phoebe, Sayomis saya; and Bohemian waxwing, Bombycilla garrulus). We

  4. A review of the mite subfamily Harpirhynchinae (Acariformes: Harpirhynchidae)--parasites of New World birds (Aves: Neognathae).

    PubMed

    Bochkov, Andre V; OConnor, Barry M; Klompen, Hans

    2015-09-30

    Mites of the subfamily Harpirhynchinae (Acariformes: Cheyletoidea: Harpirhynchidae) associated with neognathous birds (Aves: Neognathae) in the New World are revised. In all, 68 species in 8 genera are recorded. Among them, 27 new species and 1 new genus are described as new for science: Harpyrhynchoides gallowayi Bochkov, OConnor and Klompen sp. nov. from Columba livia (Columbiformes: Columbidae) from Canada (Manitoba), H. zenaida Bochkov, OConnor and Klompen sp. nov. from Zenaida macroura (Columbiformes: Columbidae) from USA (Michigan), H. calidris Bochkov, OConnor and Klompen sp. nov. from Calidris minutilla (Charadriiformes: Scolopacidae) from USA (Kansas), H. actitis Bochkov, OConnor and Klompen sp. nov. from Actitis macularius (Charadriiformes: Scolopacidae) from Canada (British Columbia), H. charadrius Bochkov, OConnor and Klompen sp. nov. from Charadrius vociferus (Charadriiformes: Charadriidae) from USA (Texas), H. pluvialis Bochkov, OConnor and Klompen sp. nov. from Pluvialis dominica (Charadriiformes: Charadriidae) from USA (Ohio), H. bubulcus Bochkov, OConnor and Klompen sp. nov. from Bubulcus ibis (Pelecaniformes: Ardeidae) from USA (Florida), H. ixobrychus Bochkov, OConnor and Klompen sp. nov. from Ixobrychus exilis (Pelecaniformes: Ardeidae) from USA (Michigan), H. puffinus Mertins sp. nov. from Puffinus gravis (Procellariformes: Procellariidae) from USA (Florida), H. megascops Bochkov, OConnor and Klompen sp. nov. from Megascops asio (Strigiformes: Strigidae) from USA (Michigan), H. athene Bochkov, OConnor and Klompen sp. nov. from Athene canicularia (Strigiformes: Strigidae) from USA (Texas), H. coccyzus Bochkov, OConnor and Klompen sp. nov. from Coccyzus americanus (Cuculiformes: Cuculidae) from USA (Michigan), H. crotophaga Bochkov, OConnor and Klompen sp. nov. from Crotophaga ani (Cuculiformes: Cuculidae) from Suriname; Crassacarus Bochkov, OConnor and Klompen, gen. nov.: Crassacarus alexfaini Bochkov, OConnor and Klompen sp. nov. (type of genus

  5. Inventory of montane-nesting birds in the Arctic Network of National Parks, Alaska

    USGS Publications Warehouse

    Tibbitts, T.L.; Ruthrauff, D.R.; Gill, R.E.; Handel, C.M.

    2006-01-01

    The Alaska Science Center of the U.S. Geological Survey conducted an inventory of birds in montane areas of the four northern parks in the Arctic Network of National Parks, Alaska. This effort represents the first comprehensive assessment of breeding range and habitat associations for the majority of avian species in the Arctic Network. Ultimately, these data provide a framework upon which to design future monitoring programs.A stratified random sampling design was used to select sample plots (n = 73 plots) that were allocated in proportion to the availability of ecological subsections. Point counts (n = 1,652) were conducted to quantify abundance, distribution, and habitat associations of birds. Field work occurred over three years (2001 to 2003) during two-week-long sessions in late May through early June that coincided with peak courtship activity of breeding birds.Totals of 53 species were recorded in Cape Krusenstern National Monument, 91 in Noatak National Preserve, 57 in Kobuk Valley National Park, and 96 in Gates of the Arctic National Park and Preserve. Substantial proportions of species in individual parks are considered species of conservation concern (18 to 26%) or species of stewardship responsibility of the land managers in the region (8 to 18%). The most commonly detected passerines on point counts included Redpoll spp. (Carduelis flammea and C. hornemanni), Savannah Sparrow (Passerculus sandwichensis), and American Tree Sparrow (Spizella arborea). The most numerous shorebirds were American Golden-Plover (Pluvialis dominica), Wilson’s Snipe (Gallinago delicata), and Whimbrel (Numenius phaeopus). Most species were detected at low rates, reflecting the low breeding densities (and/or low detectabilities) of birds in the montane Arctic. Suites of species were associated with particular ranges of elevation and showed strong associations with particular habitat types.

  6. Inter-familial relationships of the shorebirds (Aves: Charadriiformes) based on nuclear DNA sequence data

    PubMed Central

    Ericson, Per GP; Envall, Ida; Irestedt, Martin; Norman, Janette A

    2003-01-01

    Background Phylogenetic hypotheses of higher-level relationships in the order Charadriiformes based on morphological data, partly disagree with those based on DNA-DNA hybridisation data. So far, these relationships have not been tested by analysis of DNA sequence data. Herein we utilize 1692 bp of aligned, nuclear DNA sequences obtained from 23 charadriiform species, representing 15 families. We also test earlier suggestions that bustards and sandgrouses may be nested with the charadriiforms. The data is analysed with methods based on the parsimony and maximum-likelihood criteria. Results Several novel phylogenetic relationships were recovered and strongly supported by the data, regardless of which method of analysis was employed. These include placing the gulls and allied groups as a sistergroup to the sandpiper-like birds, and not to the plover-like birds. The auks clearly belong to the clade with the gulls and allies, and are not basal to most other charadriiform birds as suggested in analyses of morphological data. Pluvialis, which has been supposed to belong to the plover family (Charadriidae), represents a basal branch that constitutes the sister taxon to a clade with plovers, oystercatchers and avocets. The thick-knees and sheathbills unexpectedly cluster together. Conclusion The DNA sequence data contains a strong phylogenetic signal that results in a well-resolved phylogenetic tree with many strongly supported internodes. Taxonomically it is the most inclusive study of shorebird families that relies on nucleotide sequences. The presented phylogenetic hypothesis provides a solid framework for analyses of macroevolution of ecological, morphological and behavioural adaptations observed within the order Charadriiformes. PMID:12875664

  7. Track Analysis of the North, Central, and South American Species of the Epicauta maculata Group (Coleoptera: Meloidae).

    PubMed

    Campos-Soldini, M P; García, M S; Safenraiter, M E

    2015-08-01

    We undertook a panbiogeographic analysis of 23 species of the Epicauta maculata group of America-Epicauta abeona Pinto, Epicauta adspersa (Klug), Epicauta andersoni Werner, Epicauta atomaria (Germar), Epicauta apache Pinto, Epicauta cavernosa (Courbon), Epicauta dilatipennis Pic, Epicauta fulvicornis (Burmeister), Epicauta horni Champion, Epicauta jeffersi Pinto, Epicauta koheleri Denier, Epicauta lizeri Denier, E. maculata (Say), Epicauta magnomaculata Martin, Epicauta minutepunctata Borchmann, Epicauta nigropunctata (Blanchard), Epicauta normalis Werner, Epicauta ocellata (Dugès), Epicauta pardalis LeConte, picauta phoenix Werner, Epicauta pluvialis Borchmann, Epicauta proscripta Werner, Epicauta rubella Denier, and Epicauta ventralis Werner-with the purpose of analyzing the distributional data for taxa, to establish patterns of distribution of an ancestral biota and areas where these groups have interacted. Based on the overlap of 20 individual tracks, four generalized tracks constituted by different numbers of species were identified; two of them are located in the Nearctic region and the Mexican transition zone (tracks "A" and "B"), and the other two are distributed in the Neotropical region and the South America transition zone ("C", "D"). Six nodes were recognized: Two of them are included in the Nearctic Region, node 'I' located in northern USA and node 'II' located in southwestern USA, both at the intersection of the tracks "A" and "B". The other four are included in the Neotropical Region at the intersection of the tracks "C" and "D": Node 'III' is located in Chaco province; node 'IV' is located in Parana Forest province; node 'V' is located in the northwest of Argentina in Puna province, and node 'VI' is located in Monte province.

  8. Inventory of montane-nesting birds in Katmai and Lake Clark national parks and preserves

    USGS Publications Warehouse

    Ruthrauff, Daniel R.; Tibbitts, Lee; Gill, Robert E.; Handel, Colleen M.

    2007-01-01

    As part of the National Park Service’s Inventory and Monitoring Program, biologists from the U. S. Geological Survey’s Alaska Science Center conducted an inventory of birds in montane regions of Katmai and Lake Clark National Parks and Preserves during 2004–2006. We used a stratified random survey design to allocate samples by ecological subsection. To survey for birds, we conducted counts at 468 points across 29, 10-km x 10-km (6.2-mi x 6.2-mi) sample plots in Katmai and 417 points across 25, 10-km x 10-km sample plots in Lake Clark. We detected 92 and 104 species in Katmai and Lake Clark, respectively, including 40 species of conservation concern. We detected three species not previously recorded in Katmai (Ring-necked Duck [Aythya collaris], Lesser Scaup [Aythya affinis], and White-tailed Ptarmigan [Lagopus leucurus]) and two species not previously recorded in Lake Clark (Northern Flicker [Colaptes auratus ] and Olive-sided Flycatcher [Contopus cooperi]). The most commonly detected species in both parks was Golden-crowned Sparrow (Zonotrichia atricapilla); Fox Sparrow (Passerella iliaca) and American Pipit (Anthus rubescens) were abundant and widely-distributed as well. We defined sites as low (100–350 m), middle (351–600 m), or high (601–1,620 m) elevation based on the distribution of vegetation cover, and similarly categorized the 34 most-commonly detected species based on the mean elevation of sample points at which they were detected. High elevation (i.e., alpine) sites were characterized by high percent cover of dwarf shrub and bare ground habitat and supported species like Rock Ptarmigan (L. mutus), American Golden-Plover (Pluvialis dominica), Wandering Tattler (Tringa incana), Surfbird (Aphriza virgata), and Snow Bunting (Plectrophenax nivalis), all species of conservation concern. This inventory represents the first systematic survey of birds nesting in montane regions of both parks. Results from this inventory can form the foundation of

  9. Vision and touch in relation to foraging and predator detection: insightful contrasts between a plover and a sandpiper

    PubMed Central

    Martin, Graham R.; Piersma, Theunis

    2008-01-01

    Visual fields were determined in two species of shorebirds (Charadriiformes) whose foraging is guided primarily by different sources of information: red knots (Calidris canutus, tactile foragers) and European golden plovers (Pluvialis apricaria, visual foragers). The visual fields of both species showed features that are found in a wide range of birds whose foraging involves precision pecking or lunging at food items. Surprisingly, red knots did not show comprehensive panoramic vision as found in some other tactile feeders; they have a binocular field surrounding the bill and a substantial blind area behind the head. We argue that this is because knots switch to more visually guided foraging on their breeding grounds. However, this visual field topography leaves them vulnerable to predation, especially when using tactile foraging in non-breeding locations where predation by falcons is an important selection factor. Golden plovers use visually guided foraging throughout the year, and so it is not surprising that they have precision-pecking frontal visual fields. However, they often feed at night and this is associated with relatively large eyes. These are anchored in the skull by a wing of bone extending from the dorsal perimeter of each orbit; a skeletal structure previously unreported in birds and which we have named ‘supraorbital aliform bone’, Os supraorbitale aliforme. The larger eyes and their associated supraorbital wings result in a wide blind area above the head, which may leave these plovers particularly vulnerable to predation. Thus, in these two shorebirds, we see clear examples of the trade-off between the two key functions of visual fields: (i) the detection of predators remote from the animal and (ii) the control of accurate behaviours, such as the procurement of food items, at close quarters. PMID:18842546

  10. Migration stopovers and the conservation of arctic-breeding Calidris sandpipers

    USGS Publications Warehouse

    Skagen, S.K.

    2006-01-01

    Long-distance migration, one of the most physically demanding events in the animal kingdom, is well developed in many species of Charadriidae and Scolopacidae. Some shorebirds renowned for their extraordinary long-distance migrations, notably American Golden-Plover (Pluvialis dominica), Red Knot (Calidris canutus rufa), and White-rumped Sandpiper (C. fuscicollis), travel as many as 15,000 km between southern South American wintering grounds and Canadian Arctic breeding areas. Migration strategies of shorebirds vary in many aspects. There are remarkable accounts of shorebirds, such as northbound Red Knots, that stage a few key sites for 2-3 weeks and lay on extensive body stores, then fly nonstop for distances of [greater than or equal to] 2,500 km (Harrington 2001, Piersma et al. 2005). Less well known are the examples of populations that refuel only briefly at stopover sites, disperse broadly on the landscape, and fly shorter distances between sites (Skagen 1997, Haig et al. 1998, Warnock et al. 1998). This latter pattern applies to many long-distance migrant shorebirds that cross the interior plains of North America during spring and fall migrations. For them, interior wetland complexes provide critical refueling resources along the direct routes between summering and wintering grounds (Skagen et al. 1999). In this issue of The Auk, Krapu et al. (2006) describe patterns and implications of fat deposition by Semipalmated Sandpipers (C. pusilla), White-rumped Sandpipers, and Bairda??s Sandpipers (C. bairdii) refueling during northward migration across the prairies of mid-continental North Americaa?|

  11. Vision and touch in relation to foraging and predator detection: insightful contrasts between a plover and a sandpiper.

    PubMed

    Martin, Graham R; Piersma, Theunis

    2009-02-07

    Visual fields were determined in two species of shorebirds (Charadriiformes) whose foraging is guided primarily by different sources of information: red knots (Calidris canutus, tactile foragers) and European golden plovers (Pluvialis apricaria, visual foragers). The visual fields of both species showed features that are found in a wide range of birds whose foraging involves precision pecking or lunging at food items. Surprisingly, red knots did not show comprehensive panoramic vision as found in some other tactile feeders; they have a binocular field surrounding the bill and a substantial blind area behind the head. We argue that this is because knots switch to more visually guided foraging on their breeding grounds. However, this visual field topography leaves them vulnerable to predation, especially when using tactile foraging in non-breeding locations where predation by falcons is an important selection factor. Golden plovers use visually guided foraging throughout the year, and so it is not surprising that they have precision-pecking frontal visual fields. However, they often feed at night and this is associated with relatively large eyes. These are anchored in the skull by a wing of bone extending from the dorsal perimeter of each orbit; a skeletal structure previously unreported in birds and which we have named 'supraorbital aliform bone', Os supraorbitale aliforme. The larger eyes and their associated supraorbital wings result in a wide blind area above the head, which may leave these plovers particularly vulnerable to predation. Thus, in these two shorebirds, we see clear examples of the trade-off between the two key functions of visual fields: (i) the detection of predators remote from the animal and (ii) the control of accurate behaviours, such as the procurement of food items, at close quarters.

  12. Intense predation cannot always be detected experimentally: A case study of shorebird predation on nereid polychaetes in South Africa

    NASA Astrophysics Data System (ADS)

    Kalejta, B.

    The effect of predation by curlew sandpipers Calidris ferruginea L. and grey plovers Pluvialis squatarola (L.) on populations of nereid worms Ceratonereis keiskama (Day) and C. erythraeensis (Fauvel) was studied at the Berg River estuary, South Africa, by comparing observations of shorebird-foraging intensity with the results of a population study of two species of nereid worms within and outside bird exclosures. The study was carried out during the four-month period prior to northward migration of shorebirds. Population structure of the two nereid species differed considerably. Ceratonereis keiskama reproduced earlier than C. erythraeensis and only young individuals were present during the study. By contrast, old C. erythraeensis were available to the birds at the start of the experiment and young animals entered the population during the experiment. Despite selective predation on certain size classes of nereids by the birds, no significant changes in the population structure of either nereid were detected by the cage experiment. Numbers and biomass of both Ceratonereis spp. in paired controls and cages tracked each other and did not diverge as predicted. A consistent difference in the depth stratification of the two nereids may, however, have been due to predation pressure. Curlew sandpipers were calculated to remove 3112 nereids per m 2 during the three months, equivalent to 4.4. g (dry weight) per m 2. This represents 58% of the initial numbers and 77% of the initial biomass of nereids. Although predation on nereids by waders was exceptionally high at the Berg River estuary, any depletion in numbers or biomass of nereids caused by these predators was masked by the reproduction of the nereids. The fact that the predators' high energy requirements prior to northward migration coincide with the period of peak production of invertebrate prey makes the Berg River estuary an exceptionally favourable wintering area.

  13. A single Hox3 gene with composite bicoid and zerknüllt expression characteristics in non-Cyclorrhaphan flies

    PubMed Central

    Stauber, Michael; Prell, Alexander; Schmidt-Ott, Urs

    2002-01-01

    The members of the evolutionarily conserved Hox-gene complex, termed Hox genes, are required for specifying segmental identity during embryogenesis in various animal phyla. The Hox3 genes of winged insects have lost this ancestral function and are required for the development of extraembryonic epithelia, which do not contribute to any larval structure. Higher flies (Cyclorrhapha) such as Drosophila melanogaster contain Hox3 genes of two types, the zerknüllt type and the bicoid type. The zerknüllt gene is expressed zygotically on the dorsal side of the embryo and is required for establishing extraembryonic tissue. Its sister gene bicoid is expressed maternally and the transcripts are localized at the anterior pole of the mature egg. BICOID protein, which emerges from this localized source during early development, is required for embryonic patterning. All known direct bicoid homologues are confined to Cyclorrhaphan flies. Here, we describe Hox3 genes of the non-Cyclorrhaphan flies Empis livida (Empididae), Haematopota pluvialis (Tabanidae), and Clogmia albipunctata (Psychodidae). The gene sequences are more similar to zerknüllt homologues than to bicoid homologues, but they share expression characteristics of both genes. We propose that an ancestral Hox3 gene had been duplicated in the stem lineage of Cyclorrhaphan flies. During evolution, one of the gene copies lost maternal expression and evolved as zerknüllt, whereas the second copy lost zygotic expression and evolved as bicoid. Our finding correlates well with a partial reduction of zerknüllt-dependent extraembryonic tissue during Dipteran evolution. PMID:11773616

  14. Is it safe to nest near conspicuous neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nests

    PubMed Central

    Trottier-Paquet, Myriam; Bêty, Joël; Lamarre, Vincent; Lecomte, Nicolas

    2016-01-01

    Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, selecting nest sites protected from predators, and nesting in association with protective species. American Golden-Plovers (Pluvialis dominica) defend their territory by using various warning and distraction behaviours displayed at varying levels of intensity (hereafter “conspicuous behaviour”), as well as more aggressive behaviours such as aerial attacks, but only in some populations. Such antipredator behaviour has the potential to repel predators and thus benefit the neighbouring nests by decreasing their predation risk. Yet, conspicuous behaviour could also attract predators by signalling the presence of a nest. To test for the existence of a protective effect associated with the conspicuous antipredator behaviour of American Golden-Plovers, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests would decrease with proximity to and density of plover nests. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200, and 500 m from seven of those plover nests. We found that the predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represents a key step to better understand the importance of these species of conservation concern in tundra food webs. PMID:27602257

  15. Is it safe to nest near conspicuous neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nests.

    PubMed

    Giroux, Marie-Andrée; Trottier-Paquet, Myriam; Bêty, Joël; Lamarre, Vincent; Lecomte, Nicolas

    2016-01-01

    Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, selecting nest sites protected from predators, and nesting in association with protective species. American Golden-Plovers (Pluvialis dominica) defend their territory by using various warning and distraction behaviours displayed at varying levels of intensity (hereafter "conspicuous behaviour"), as well as more aggressive behaviours such as aerial attacks, but only in some populations. Such antipredator behaviour has the potential to repel predators and thus benefit the neighbouring nests by decreasing their predation risk. Yet, conspicuous behaviour could also attract predators by signalling the presence of a nest. To test for the existence of a protective effect associated with the conspicuous antipredator behaviour of American Golden-Plovers, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests would decrease with proximity to and density of plover nests. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200, and 500 m from seven of those plover nests. We found that the predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represents a key step to better understand the importance of these species of conservation concern in tundra food webs.

  16. Wind effects on prey availability: How northward migrating waders use brackish and hypersaline lagoons in the sivash, Ukraine

    NASA Astrophysics Data System (ADS)

    Verkuil, Yvonne; Koolhaas, Anita; Van Der Winden, Jan

    Large numbers of waders migrating northward in spring use the Sivash, a large system of shallow, brackish and hypersaline lagoons in the Black Sea and Azov Sea region (Ukraine). The bottoms of these lagoons are often uncovered by the wind. Hence, for waders the time and space available for feeding depend on wind conditions. In hypersaline lagoons the benthic and pelagic fauna was very poor, consisting mainly of chironomid larvae (0.19 g AFDM·m -2) and brine shrimps Artemia salina, respectively. Brine shrimp abundance was correlated with salinity, wind force, wind direction and water depth. Dunlin Calidris alpina and curlew sandpiper Calidris ferruginea were the only species feeding on brine shrimp. As brine shrimp densities are higher in deeper water, smaller waders such as broad-billed sandpipers Limicola falcinellus are too short-legged to reach exploitable densities of brine shrimp. In brackish lagoons the benthic and pelagic fauna was rich, consisting of polychaetes, bivalves, gastropods, chironomid larvae, isopods and amphipods (8.9 to 30.5 g AFDM·m -2), but there were no brine shrimps. Prey biomass increased with the distance from the coast, being highest on the site that was most frequently inundated. Dunlin, broad-billed sandpiper and grey plover Pluvialis squatarola were the most abundant birds in the brackish lagoon. Due to the effects of wind-tides only a small area was usually available as a feeding site. Gammarus insensibilis was the alternative prey resource in the water layer, and their density varied with wind direction in the same way as brine shrimp. Curlew sandpipers and dunlins in the hypersaline lagoons and broad-billed sandpipers in the brackish lagoons often changed feeding sites, probably following the variation in prey availability. Only because of the large size and variety of lagoons are waders in the Sivash always able to find good feeding sites.

  17. An experimental assessment of vehicle disturbance effects on migratory shorebirds

    USGS Publications Warehouse

    Tarr, Nathan M.; Simons, T.R.; Pollock, K.H.

    2010-01-01

    Off-road vehicle (ORV) traffic is one of several forms of disturbance thought to affect shorebirds at migration stopover sites. Attempts to measure disturbance effects on shorebird habitat use and behavior at stopover sites are difficult because ORV disturbance is frequently confounded with habitat and environmental factors. We used a before-after-control-impact experimental design to isolate effects of vehicle disturbance from shorebird responses to environmental and habitat factors. We manipulated disturbance levels within beach closures along South Core Banks, North Carolina, USA, and measured changes in shorebird abundance and location, as well as the activity of one focal species, the sanderling (Calidris alba), within paired control and impact plots. We applied a discrete treatment level of one flee-response-inducing event every 10 minutes on impact plots. We found that disturbance reduced total shorebird and black-bellied plover (Pluvialis squatarola) abundance and reduced relative use of microhabitat zones above the swash zone (wet sand and dry sand) by sanderlings, black-bellied plovers, willets (Tringa semipalmata), and total shorebirds. Sanderlings and total shorebirds increased use of the swash zone in response to vehicle disturbance. Disturbance reduced use of study plots by sanderlings for resting and increased sanderling activity, but we did not detect an effect of vehicle disturbance on sanderling foraging activity. We provide the first estimates of how a discrete level of disturbance affects shorebird distributions among ocean beach microhabitats. Our findings provide a standard to which managers can compare frequency and intensity of disturbance events at other shorebird stopover and roosting sites and indicate that limiting disturbance will contribute to use of a site by migratory shorebirds. ?? 2010 The Wildlife Society.

  18. Control of cytokinin and auxin homeostasis in cyanobacteria and algae

    PubMed Central

    Žižková, Eva; Kubeš, Martin; Dobrev, Petre I.; Přibyl, Pavel; Šimura, Jan; Zahajská, Lenka; Záveská Drábková, Lenka; Novák, Ondřej; Motyka, Václav

    2017-01-01

    Background and Aims The metabolism of cytokinins (CKs) and auxins in vascular plants is relatively well understood, but data concerning their metabolic pathways in non-vascular plants are still rather rare. With the aim of filling this gap, 20 representatives of taxonomically major lineages of cyanobacteria and algae from Cyanophyceae, Xanthophyceae, Eustigmatophyceae, Porphyridiophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae, Zygnematophyceae and Klebsormidiophyceae were analysed for endogenous profiles of CKs and auxins and some of them were used for studies of the metabolic fate of exogenously applied radiolabelled CK, [3H]trans-zeatin (transZ) and auxin ([3H]indole-3-acetic acid (IAA)), and the dynamics of endogenous CK and auxin pools during algal growth and cell division. Methods Quantification of phytohormone levels was performed by high-performance or ultrahigh-performance liquid chromatography–electrospray tandem mass spectrometry (HPLC-MS/MS, UHPLC-MS/MS). The dynamics of exogenously applied [3H]transZ and [3H]IAA in cell cultures were monitored by HPLC with on-line radioactivity detection. Key Results The comprehensive screen of selected cyanobacteria and algae for endogenous CKs revealed a predominance of bioactive and phosphate CK forms while O- and N-glucosides evidently did not contribute greatly to the total CK pool. The abundance of cis-zeatin-type CKs and occurrence of CK 2-methylthio derivatives pointed to the tRNA pathway as a substantial source of CKs. The importance of the tRNA biosynthetic pathway was proved by the detection of tRNA-bound CKs during the course of Scenedesmus obliquus growth. Among auxins, free IAA and its oxidation catabolite 2-oxindole-3-acetic acid represented the prevailing endogenous forms. After treatment with [3H]IAA, IAA-aspartate and indole-3-acetyl-1-glucosyl ester were detected as major auxin metabolites. Moreover, different dynamics of endogenous CKs and auxin profiles during S. obliquus culture clearly

  19. Inferring Phytoplankton, Terrestrial Plant and Bacteria Bulk δ¹³C Values from Compound Specific Analyses of Lipids and Fatty Acids

    PubMed Central

    Taipale, Sami J.; Peltomaa, Elina; Hiltunen, Minna; Jones, Roger I.; Hahn, Martin W.; Biasi, Christina; Brett, Michael T.

    2015-01-01

    Stable isotope mixing models in aquatic ecology require δ13C values for food web end members such as phytoplankton and bacteria, however it is rarely possible to measure these directly. Hence there is a critical need for improved methods for estimating the δ13C ratios of phytoplankton, bacteria and terrestrial detritus from within mixed seston. We determined the δ13C values of lipids, phospholipids and biomarker fatty acids and used these to calculate isotopic differences compared to the whole-cell δ13C values for eight phytoplankton classes, five bacterial taxa, and three types of terrestrial organic matter (two trees and one grass). The lipid content was higher amongst the phytoplankton (9.5±4.0%) than bacteria (7.3±0.8%) or terrestrial matter (3.9±1.7%). Our measurements revealed that the δ13C values of lipids followed phylogenetic classification among phytoplankton (78.2% of variance was explained by class), bacteria and terrestrial matter, and there was a strong correlation between the δ13C values of total lipids, phospholipids and individual fatty acids. Amongst the phytoplankton, the isotopic difference between biomarker fatty acids and bulk biomass averaged -10.7±1.1‰ for Chlorophyceae and Cyanophyceae, and -6.1±1.7‰ for Cryptophyceae, Chrysophyceae and Diatomophyceae. For heterotrophic bacteria and for type I and type II methane-oxidizing bacteria our results showed a -1.3±1.3‰, -8.0±4.4‰, and -3.4±1.4‰ δ13C difference, respectively, between biomarker fatty acids and bulk biomass. For terrestrial matter the isotopic difference averaged -6.6±1.2‰. Based on these results, the δ13C values of total lipids and biomarker fatty acids can be used to determine the δ13C values of bulk phytoplankton, bacteria or terrestrial matter with ± 1.4‰ uncertainty (i.e., the pooled SD of the isotopic difference for all samples). We conclude that when compound-specific stable isotope analyses become more widely available, the determination of

  20. Dynamics of Sundarban estuarine ecosystem: eutrophication induced threat to mangroves

    PubMed Central

    2010-01-01

    Background Sundarbans is the largest chunk of mangrove forest and only tiger mangrove land in the world. Compared to the rich species diversity and uniqueness, very few studies have so far been conducted here, mainly due to its inaccessibility. This study explores water quality, density of biomass, species diversity, phytoplankton abundance and bacterial population of a tidal creek in Sunderban estuary during the post and pre monsoon period of 2008-09. Results Phytoplankton community was observed to be dominated by diatoms (Biacillariophyceae) followed by Pyrrophyceae (Dinoflagellates) and Chlorophyceae. A total of 46 taxa belonging to 6 groups were recorded. Other algal groups were Cyanophyceae, Euglenophyceae and Chrysophyceae. Species diversity was highest in summer (March) and lowest in winter season (November) in all the sample stations indicating its close correlation with ambient temperature. Species evenness was fairly high in all five stations throughout the study period. Present study indicated that dissolved oxygen, nutrients and turbidity are the limiting factors for the phytoplankton biomass. The estuary was in eutrophic condition (Chlorophyll-a ≥10 μg/L) in winter. During the month of May phytoplankton biomass declined and at high salinity level (21.2PSU) new phytoplankton species take over, which are definitely better resilient to the high saline environment. Bio-indicator species like Polykrikos schwartzil, Dinophysis norvegica and Prorocentrum concavum points to moderately polluted water quality of the estuary. Conclusion Eutrophication as well as presence of toxic Dinoflagellates and Cyanophyceae in the tidal creek of Sundarban estuary definitely revealed the deteriorated status of the water quality. The structure and function of the mangrove food web is unique, driven by both marine and terrestrial components. But little attention has been paid so far to the adaptive responses of mangrove biota to the various disturbances, and now our work

  1. The Dunaliella salina organelle genomes: large sequences, inflated with intronic and intergenic DNA

    SciTech Connect

    Smith, David R.; Lee, Robert W.; Cushman, John C.; Magnuson, Jon K.; Tran, Duc; Polle, Juergen E.

    2010-05-07

    Abstract Background: Dunaliella salina Teodoresco, a unicellular, halophilic green alga belonging to the Chlorophyceae, is among the most industrially important microalgae. This is because D. salina can produce massive amounts of β-carotene, which can be collected for commercial purposes, and because of its potential as a feedstock for biofuels production. Although the biochemistry and physiology of D. salina have been studied in great detail, virtually nothing is known about the genomes it carries, especially those within its mitochondrion and plastid. This study presents the complete mitochondrial and plastid genome sequences of D. salina and compares them with those of the model green algae Chlamydomonas reinhardtii and Volvox carteri. Results: The D. salina organelle genomes are large, circular-mapping molecules with ~60% noncoding DNA, placing them among the most inflated organelle DNAs sampled from the Chlorophyta. In fact, the D. salina plastid genome, at 269 kb, is the largest complete plastid DNA (ptDNA) sequence currently deposited in GenBank, and both the mitochondrial and plastid genomes have unprecedentedly high intron densities for organelle DNA: ~1.5 and ~0.4 introns per gene, respectively. Moreover, what appear to be the relics of genes, introns, and intronic open reading frames are found scattered throughout the intergenic ptDNA regions -- a trait without parallel in other characterized organelle genomes and one that gives insight into the mechanisms and modes of expansion of the D. salina ptDNA. Conclusions: These findings confirm the notion that chlamydomonadalean algae have some of the most extreme organelle genomes of all eukaryotes. They also suggest that the events giving rise to the expanded ptDNA architecture of D. salina and other Chlamydomonadales may have occurred early in the evolution of this lineage. Although interesting from a genome evolution standpoint, the D. salina organelle DNA sequences will aid in the development of a viable

  2. Phytoplankton community and chlorophyll a as trophic state indices of Lake Skadar (Montenegro, Balkan).

    PubMed

    Rakocevic-Nedovic, Jelena; Hollert, Henner

    2005-01-01

    Phytoplankton, as a first step in trophic cascades of lakes, can be a good indicator of trophic states, considering that every environmental change affects this community and many species of this community are sensitive to changes, and that they response very quickly. In this study, we tried to assess and predict the trophic state of Lake Skadar according to phytoplankton data. Water samples were collected using Ruttner sampling bottle. Temperature, dissolved oxygen, ph, conductivity and transparence were measured in situ using portable equipment. Nutrients and chlorophyll a were measured using standard spectrophotometric methods. A determination of phytoplankton species was performed using relevant keys and the counting of cells was performed using sedimentation methods. The species composition of Lake Skadar revealed 95 taxa, with Chlorophyceae and Bacillariophyceae being represented best. According to an average chlorophyll a concentration of 5.9 pg/l, Lake Skadar belongs to the mesotrophic level of the trophic scale. Developed prediction equation for chlorophyll a revealed a good prediction (R2 = 0.71) and the parameter Secchi depth was primarily correlated with chlorophyll a concentration. Trophic state indices derived from chlorophyll a and transparency, were close together, but both were below the phosphorous index. Values of trophic state indices rank the Lake Skadar as being mesotrophic. This study also showed that indices of diversity based on phytoplankton are weak indicators of trophic status and that they can well characterize only differences between assemblages and associations. According to calculated saprobic indices (ranging from 1.5 to 2.15), Lake Skadar is on betamesosaprobic level of saprobity, which means that it is moderately polluted with organic compounds. Total phosphorus is not the main limiting factor for the phytoplankton community in Lake Skadar. Disagreements between chlorophyll and the transparency index, on the one hand, and the

  3. Toxic substances in surface waters and sediments--A study to assess the effects of arsenic-contaminated alluvial sediment in Whitewood Creek, South Dakota

    USGS Publications Warehouse

    Kuwabara, James S.; Fuller, Christopher C.

    2003-01-01

    Field measurements and bioassay experiments were done to investigate the effects of arsenic and phosphorus interactions on sorption of these solutes by the benthic flora (periphyton and submerged macrophytes) in Whitewood Creek, a stream in western South Dakota. Short-term (24-hour) sorption experiments were used to determine arsenic transport characteristics for algae (first-order rate constants for solute sorption, biomass, and accumulation factors) collected in the creek along a transect beginning upstream from a mine discharge point and downgradient through a 57-kilometer reach. Temporal changes in biomass differed significantly between and within sampling sites. Arsenic concentrations in plant tissue increased with distance downstream, but temporal changes in concentrations in tissues differed considerably from site to site. Cultures of Achnanthes minutissima (Bacillariophyceae) and Stichococcus sp. (Chlorophyceae) were isolated from four sites along a longitudinal concentration gradient of dissolved arsenic within the study reach and were maintained at ambient solute concentrations. Arsenic accumulation factors and sorption-rate constants for these isolates were determined as a function of dissolved arsenate and orthophosphate. Cell surfaces of algal isolates exhibited preferential orthophosphate sorption over arsenate. Initial sorption of both arsenate and orthophosphate followed first-order mass transfer for each culturing condition. Although sorption-rate constants increased slightly with increased dissolved-arsenate concentration, algae, isolated from a site with elevated dissolved arsenic in the stream channel, had a significantly slower rate of arsenic sorption compared with the same species isolated from an uncontaminated site upstream. In diel studies, amplitudes of the pH cycles increased with measured biomass except at a site immediately downstream from water-treatment-plant discharge. Inorganic pentavalent arsenic dominated arsenic speciation at

  4. Control of cytokinin and auxin homeostasis in cyanobacteria and algae.

    PubMed

    Žižková, Eva; Kubeš, Martin; Dobrev, Petre I; Přibyl, Pavel; Šimura, Jan; Zahajská, Lenka; Záveská Drábková, Lenka; Novák, Ondřej; Motyka, Václav

    2017-01-01

    The metabolism of cytokinins (CKs) and auxins in vascular plants is relatively well understood, but data concerning their metabolic pathways in non-vascular plants are still rather rare. With the aim of filling this gap, 20 representatives of taxonomically major lineages of cyanobacteria and algae from Cyanophyceae, Xanthophyceae, Eustigmatophyceae, Porphyridiophyceae, Chlorophyceae, Ulvophyceae, Trebouxiophyceae, Zygnematophyceae and Klebsormidiophyceae were analysed for endogenous profiles of CKs and auxins and some of them were used for studies of the metabolic fate of exogenously applied radiolabelled CK, [(3)H]trans-zeatin (transZ) and auxin ([(3)H]indole-3-acetic acid (IAA)), and the dynamics of endogenous CK and auxin pools during algal growth and cell division. Quantification of phytohormone levels was performed by high-performance or ultrahigh-performance liquid chromatography-electrospray tandem mass spectrometry (HPLC-MS/MS, UHPLC-MS/MS). The dynamics of exogenously applied [(3)H]transZ and [(3)H]IAA in cell cultures were monitored by HPLC with on-line radioactivity detection. The comprehensive screen of selected cyanobacteria and algae for endogenous CKs revealed a predominance of bioactive and phosphate CK forms while O- and N-glucosides evidently did not contribute greatly to the total CK pool. The abundance of cis-zeatin-type CKs and occurrence of CK 2-methylthio derivatives pointed to the tRNA pathway as a substantial source of CKs. The importance of the tRNA biosynthetic pathway was proved by the detection of tRNA-bound CKs during the course of Scenedesmus obliquus growth. Among auxins, free IAA and its oxidation catabolite 2-oxindole-3-acetic acid represented the prevailing endogenous forms. After treatment with [(3)H]IAA, IAA-aspartate and indole-3-acetyl-1-glucosyl ester were detected as major auxin metabolites. Moreover, different dynamics of endogenous CKs and auxin profiles during S. obliquus culture clearly demonstrated diverse roles of both

  5. Microbial assemblages in soil microbial succession after glacial retreat in Svalbard (high arctic).

    PubMed

    Kastovská, Klára; Elster, Josef; Stibal, Marek; Santrůcková, Hana

    2005-10-01

    Microbial community composition (cyanobacteria and eukaryotic microalgae abundance and diversity, bacterial abundance, and soil respiration) was studied in subglacial and periglacial habitats on five glaciers near Ny-Alesund, Svalbard (79 degrees N). Soil microbial communities from nonvegetated sites (subglacial, recently deglaciated, and cryoconite sediments) and sites with plant cover (deglaciated some hundreds of years ago) were analyzed. Physicochemical analyses (pH, texture, water content, organic matter, total C and N content) were also performed on the samples. In total, 57 taxa of 23 genera of cyanobacteriaand algae were identified. Algae from the class Chlorophyceae (25 species) and cyanobacteria (23 species) were richest in biodiversity. The numbers of identified species in single habitat types were 23 in subglacial, 39 inbarren, 22 in cryoconite, and 24 in vegetated soils. The highest cyanobacterial and algal biovolume and cell numbers, respectively, were present in cryoconite (13x10(4) microm3 mg-1 soil and 508 cells per mg of soil), followed by barren (5.7x10(4) and 188), vegetated (2.6x10(4) and 120), and subglacial (0.1x10(4) and 5) soils. Cyanobacteria prevailed in all soil samples. Algae (mainly green algae) were present only as accessory organisms. The density of bacteria showed a slightly different trend to that of the cyanobacterial and algal assemblages. The highest number of bacteria was present in vegetated (mean: 13,722x10(8) cells per mg of soil dry wt.), followed by cryoconite (3802x10(8)), barren (654x10(8)), and subglacial (78x10(8)) soils. Response of cyanobacteria and algae to physical parameters showed that soil texture and water content are important for biomass development. In addition, it is shown that nitrogen and water content are the main factors affecting bacterial abundance and overall soil respiration. Redundancy analysis (RDA) with forward selection was used to create a model explaining variability in cyanobacterial, algal

  6. Molecular Characterization of a Heteromeric ATP-Citrate Lyase That Generates Cytosolic Acetyl-Coenzyme A in Arabidopsis1[w

    PubMed Central

    Fatland, Beth L.; Ke, Jinshan; Anderson, Marc D.; Mentzen, Wieslawa I.; Cui, Li Wei; Allred, C. Christy; Johnston, Jerry L.; Nikolau, Basil J.; Wurtele, Eve Syrkin

    2002-01-01

    Acetyl-coenzyme A (CoA) is used in the cytosol of plant cells for the synthesis of a diverse set of phytochemicals including waxes, isoprenoids, stilbenes, and flavonoids. The source of cytosolic acetyl-CoA is unclear. We identified two Arabidopsis cDNAs that encode proteins similar to the amino and carboxy portions of human ATP-citrate lyase (ACL). Coexpression of these cDNAs in yeast (Saccharomyces cerevisiae) confers ACL activity, indicating that both the Arabidopsis genes are required for ACL activity. Arabidopsis ACL is a heteromeric enzyme composed of two distinct subunits, ACLA (45 kD) and ACLB (65 kD). The holoprotein has a molecular mass of 500 kD, which corresponds to a heterooctomer with an A4B4 configuration. ACL activity and the ACLA and ACLB polypeptides are located in the cytosol, consistent with the lack of targeting peptides in the ACLA and ACLB sequences. In the Arabidopsis genome, three genes encode for the ACLA subunit (ACLA-1, At1g10670; ACLA-2, At1g60810; and ACLA-3, At1g09430), and two genes encode the ACLB subunit (ACLB-1, At3g06650 and ACLB-2, At5g49460). The ACLA and ACLB mRNAs accumulate in coordinated spatial and temporal patterns during plant development. This complex accumulation pattern is consistent with the predicted physiological needs for cytosolic acetyl-CoA, and is closely coordinated with the accumulation pattern of cytosolic acetyl-CoA carboxylase, an enzyme using cytosolic acetyl-CoA as a substrate. Taken together, these results indicate that ACL, encoded by the ACLA and ACLB genes of Arabidopsis, generates cytosolic acetyl-CoA. The heteromeric organization of this enzyme is common to green plants (including Chlorophyceae, Marchantimorpha, Bryopsida, Pinaceae, monocotyledons, and eudicots), species of fungi, Glaucophytes, Chlamydomonas, and prokaryotes. In contrast, all known animal ACL enzymes have a homomeric structure, indicating that a evolutionary fusion of the ACLA and ACLB genes probably occurred early in the

  7. Seasonal variations of plankton diversity in the Kaduviyar estuary, Nagapattinam, southeast coast of India.

    PubMed

    Perumal, N Vengadesh; Rajkumar, M; Perumal, P; Rajasekar, K Thillai

    2009-11-01

    The results of an investigation carried out during October 2005 to September 2006 on hydrography composition and community structure of phytoplankton and zooplankton including chlorophyll 'a' (Chl-a) content and primary productivity (PP) at the Kaduviyar estuary (Southeast coast of India) are reported. Air and surface water temperatures (degrees C) varied from 23 to 29 and from 24 to 31 respectively while the light extinction coefficient values (LEC) ranged between 0.15 and 0.59. Salinity values (per thousand) varied from 4 to 34 and the pH ranged between 7.8 and 8.3. Variation in dissolved oxygen content was from 3.06 to 5.63 mg l(-1). The ranges of inorganic nutrients (microM) viz., nitrate, nitrite, phosphate, silicate and ammonia were: 0.36-12.65; 0.06-1.86; 0.06-4.57; 17.96-235.06 and 0.001-0.75 respectively. The ranges of Chlorophyll 'a' (mg m(-3)) and the primary productivity (mg Cm(-3) hr(-1)) values were: 3.4-12.8 and 55-119 respectively. Presently, 85 phytoplankton species representing different classes viz: Bacillariophyceae (58); Dinophyceae (16); Cyanophyceae (7); Chlorophyceae (3) and Chrysophyceae (1) were recorded. The phytoplankton density varied from 14,135 to 74,697 cells l(-1), with peak diversity (3.46 bits ind.(-1)) during premonsoon season. The maximum density was found during summer season coinciding with the stable hydrographical conditions. Totally 92 species of zooplankton besides 18 larvae were recorded and the copepods formed the dominant group. The occurrence of most of the zooplankton species showed a distinct seasonal pattern, which was closely associated with the species-specific environmental conditions. That way the environmental factors exert major influence on the species composition, abundance and diversity of zooplankton. The zooplankton density (org. l(-1)) ranged between 4342 and 14,002 and between 4867 and 15,816 at stations 1 and 2 respectively. Kaduviyar estuarine waters were very rich in zooplankton diversity (bits ind