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Sample records for algal extracellular products

  1. Growth of Heterotrophic Bacteria and Algal Extracellular Products in Oligotrophic Waters

    PubMed Central

    McFeters, Gordon A.; Stuart, Sidney A.; Olson, Susan B.

    1978-01-01

    The unexpected observation of 200 to 400 coliform bacteria per 100 ml in an unpolluted pristine stream was studied within Grand Teton National Park, Wyo. The high numbers of waterborne bacteria occurred in mid- to late summer at a location where there was a coincidental bloom of an algal mat community. Periphyton samplers were used to measure the algal growth that coincided with the increase in number of bacteria. Laboratory studies followed the growth of various coliform bacteria in the supernatant obtained from a Chlorella culture isolated from the mat community. Mixed natural bacterial populations from the stream and pure cultures of water-isolated fecal and nonfecal coliforms increased by two to three orders of magnitude at 13°C when grown in the algal supernatant. Radioactive algal products were obtained by feeding an axenic Chlorella culture 14C-labeled bicarbonate under laboratory cultivation at 13°C with illumination. Radioactive organic material from the algae became incorporated into the particulate fraction of pure cultures of coliform bacteria as they reproduced and was later released as they died. PMID:16345278

  2. Temperature and Light Effects on Extracellular Superoxide Production by Algal and Bacterial Symbionts in Corals: Implications for Coral Bleaching

    NASA Astrophysics Data System (ADS)

    Brighi, C.; Diaz, J. M.; Apprill, A.; Hansel, C. M.

    2014-12-01

    Increased surface seawater temperature due to global warming is one of the main causes of coral bleaching, a phenomenon in which corals lose their photosynthetic algae. Light and temperature induced production of superoxide and other reactive oxygen species (ROS) by these symbiotic algae has been implicated in the breakdown of their symbiotic association with the coral host and subsequent coral bleaching. Nevertheless, a direct link between Symbiodinium ROS production and coral bleaching has not been demonstrated. In fact, given the abundance and diversity of microorganisms within the coral holobiont, the concentration and fluxes of ROS within corals may involve several microbial sources and sinks. Here, we explore the role of increased light and temperature on superoxide production by coral-derived cultures of Symbiodinium algae and Oceanospirillales bacteria of the genus Endozoicomonas, which are globally common and abundant associates of corals. Using a high sensitivity chemiluminescent technique, we find that heat stress (exposure to 34°C vs. 23°C for 2hr or 24hr) has no significant effect on extracellular superoxide production by Symbiodinium isolates within clades B and C, regardless of the level of light exposure. Exposure to high light, however, increased superoxide production by these organisms at both 34°C and 23°C. On the other hand, extracellular superoxide production by Endozoicomonas bacteria tested under the same conditions was stimulated by the combined effects of thermal and light stress. The results of this research suggest that the sources and physical triggers for biological superoxide production within corals are more complex than currently assumed. Thus, further investigations into the biological processes controlling ROS dynamics within corals are required to improve our understanding of the mechanisms underpinning coral bleaching and to aid in the development of mitigation strategies.

  3. Air pollutant production by algal cell cultures

    NASA Technical Reports Server (NTRS)

    Fong, F.; Funkhouser, E. A.

    1982-01-01

    The production of phytotoxic air pollutants by cultures of Chlorella vulgaris and Euglena gracilis is considered. Algal and plant culture systems, a fumigation system, and ethylene, ethane, cyanide, and nitrogen oxides assays are discussed. Bean, tobacco, mustard green, cantaloupe and wheat plants all showed injury when fumigated with algal gases for 4 hours. Only coleus plants showed any resistance to the gases. It is found that a closed or recycled air effluent system does not produce plant injury from algal air pollutants.

  4. Coupling of algal biofuel production with wastewater.

    PubMed

    Bhatt, Neha Chamoli; Panwar, Amit; Bisht, Tara Singh; Tamta, Sushma

    2014-01-01

    Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area.

  5. Coupling of Algal Biofuel Production with Wastewater

    PubMed Central

    Panwar, Amit; Bisht, Tara Singh; Tamta, Sushma

    2014-01-01

    Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area. PMID:24982930

  6. Exploring the Utilization of Complex Algal Communities to Address Algal Pond Crash and Increase Annual Biomass Production for Algal Biofuels

    SciTech Connect

    Hamilton, Cyd E.

    2014-03-25

    This white paper briefly reviews the research literature exploring complex algal communities as a means of increasing algal biomass production via increased tolerance, resilience, and resistance to a variety of abiotic and biotic perturbations occurring within harvesting timescales. This paper identifies what data are available and whether more research utilizing complex communities is needed to explore the potential of complex algal community stability (CACS) approach as a plausible means to increase biomass yields regardless of ecological context and resulting in decreased algal-based fuel prices by reducing operations costs. By reviewing the literature for what we do and do not know, in terms of CACS methodologies, this report will provide guidance for future research addressing pond crash phenomena.

  7. Algal recycling enhances algal productivity and settleability in Pediastrum boryanum pure cultures.

    PubMed

    Park, Jason B K; Craggs, Rupert J; Shilton, Andy N

    2015-12-15

    Recycling a portion of gravity harvested algae (i.e. algae and associated bacteria biomass) has been shown to improve both algal biomass productivity and harvest efficiency by maintaining the dominance of a rapidly-settleable colonial alga, Pediastrum boryanum in both pilot-scale wastewater treatment High Rate Algal Ponds (HRAP) and outdoor mesocosms. While algal recycling did not change the relative proportions of algae and bacteria in the HRAP culture, the contribution of the wastewater bacteria to the improved algal biomass productivity and settleability with the recycling was not certain and still required investigation. P. boryanum was therefore isolated from the HRAP and grown in pure culture on synthetic wastewater growth media under laboratory conditions. The influence of recycling on the productivity and settleability of the pure P. boryanum culture was then determined without wastewater bacteria present. Six 1 L P. boryanum cultures were grown over 30 days in a laboratory growth chamber simulating New Zealand summer conditions either with (Pr) or without (Pc) recycling of 10% of gravity harvested algae. The cultures with recycling (Pr) had higher algal productivity than the controls (Pc) when the cultures were operated at both 4 and 3 d hydraulic retention times by 11% and 38% respectively. Furthermore, algal recycling also improved 1 h settleability from ∼60% to ∼85% by increasing the average P. boryanum colony size due to the extended mean cell residence time and promoted formation of large algal bio-flocs (>500 μm diameter). These results demonstrate that the presence of wastewater bacteria was not necessary to improve algal productivity and settleability with algal recycling.

  8. Optimizing algal cultivation & productivity : an innovative, multidiscipline, and multiscale approach.

    SciTech Connect

    Murton, Jaclyn K.; Hanson, David T.; Turner, Tom; Powell, Amy Jo; James, Scott Carlton; Timlin, Jerilyn Ann; Scholle, Steven; August, Andrew; Dwyer, Brian P.; Ruffing, Anne; Jones, Howland D. T.; Ricken, James Bryce; Reichardt, Thomas A.

    2010-04-01

    Progress in algal biofuels has been limited by significant knowledge gaps in algal biology, particularly as they relate to scale-up. To address this we are investigating how culture composition dynamics (light as well as biotic and abiotic stressors) describe key biochemical indicators of algal health: growth rate, photosynthetic electron transport, and lipid production. Our approach combines traditional algal physiology with genomics, bioanalytical spectroscopy, chemical imaging, remote sensing, and computational modeling to provide an improved fundamental understanding of algal cell biology across multiple cultures scales. This work spans investigations from the single-cell level to ensemble measurements of algal cell cultures at the laboratory benchtop to large greenhouse scale (175 gal). We will discuss the advantages of this novel, multidisciplinary strategy and emphasize the importance of developing an integrated toolkit to provide sensitive, selective methods for detecting early fluctuations in algal health, productivity, and population diversity. Progress in several areas will be summarized including identification of spectroscopic signatures for algal culture composition, stress level, and lipid production enabled by non-invasive spectroscopic monitoring of the photosynthetic and photoprotective pigments at the single-cell and bulk-culture scales. Early experiments compare and contrast the well-studied green algae chlamydomonas with two potential production strains of microalgae, nannochloropsis and dunnaliella, under optimal and stressed conditions. This integrated approach has the potential for broad impact on algal biofuels and bioenergy and several of these opportunities will be discussed.

  9. Algal production in wastewater treatment high rate algal ponds for potential biofuel use.

    PubMed

    Park, J B K; Craggs, R J

    2011-01-01

    Wastewater treatment High Rate Algal Ponds with CO2 addition could provide cost-effective and efficient tertiary-level wastewater treatment with the co-benefit of algal biomass production for biofuel use. Wastewater grown algal biomass can have a lipid content of 10-30% of dry weight, which could be used to make biodiesel. This research investigated algal biomass and total lipid production by two pilot-scale wastewater treatment HRAP(S) (4-day HRT) with and without CO2 addition under New Zealand mid summer (Nov-Jan) conditions. The influence of CO2 addition on wastewater treatment performance was also determined. CO2 was added to one of the HRAPs (the HRAP(E)) by maintaining the maximum pH of the pond below 8. Measurements of HRAP influent and effluent water qualities, total lipid content and algal biomass production were made twice a week over the experimental period. Both HRAP(S) achieved high levels of organic compound and nutrient removal, with >85% SBOD5, >92 NH4(+)-N and >70% DRP removal. Algal/bacterial biomass production in the HRAP(E) (15.2 g/m2/d) was improved by CO2 addition by approximately 30% compared with that of the control HRAP(W) (10.6 g/m2/d). Total lipid content of the biomass grown on both HRAP(S) was slightly reduced (from 25% to 20%) with CO2 addition and the maximum total lipid content of approximately 40% was observed in the HRAP(W) when low NH4(+)-N concentration (<0.5 mg/L) and high maximum pH (>10.0) occurred. Total lipid content of the biomass increased by approximately 15% under nitrogen limiting conditions, however, overall algal/bacterial biomass production was reduced by half during the period of nitrogen limitation. More research is required to maintain algal production under near nitrogen-limiting conditions. PMID:21977667

  10. Investigating why recycling gravity harvested algae increases harvestability and productivity in high rate algal ponds.

    PubMed

    Park, J B K; Craggs, R J; Shilton, A N

    2013-09-15

    It has previously been shown that recycling gravity harvested algae promotes Pediastrum boryanum dominance and improves harvestability and biomass production in pilot-scale High Rate Algal Ponds (HRAPs) treating domestic wastewater. In order to confirm the reproducibility of these findings and investigate the mechanisms responsible, this study utilized twelve 20 L outdoor HRAP mesocosms operated with and without algal recycling. It then compared the recycling of separated solid and liquid components of the harvested biomass against un-separated biomass. The work confirmed that algal recycling promoted P. boryanum dominance, improved 1 h-settleability by >20% and increased biomass productivity by >25% compared with controls that had no recycling. With regard to the improved harvestability, of particular interest was that recycling the liquid fraction alone caused a similar improvement in settleability as recycling the solid fraction. This may be due to the presence of extracellular polymeric substances in the liquid fraction. While there are many possible mechanisms that could account for the increased productivity with algal recycling, all but two were systematically eliminated: (i) the mean cell residence time was extended thereby increasing the algal concentration and more fully utilizing the incident sunlight and, (ii) the relative proportions of algal growth stages (which have different specific growth rates) was changed, resulting in a net increase in the overall growth rate of the culture.

  11. Investigating why recycling gravity harvested algae increases harvestability and productivity in high rate algal ponds.

    PubMed

    Park, J B K; Craggs, R J; Shilton, A N

    2013-09-15

    It has previously been shown that recycling gravity harvested algae promotes Pediastrum boryanum dominance and improves harvestability and biomass production in pilot-scale High Rate Algal Ponds (HRAPs) treating domestic wastewater. In order to confirm the reproducibility of these findings and investigate the mechanisms responsible, this study utilized twelve 20 L outdoor HRAP mesocosms operated with and without algal recycling. It then compared the recycling of separated solid and liquid components of the harvested biomass against un-separated biomass. The work confirmed that algal recycling promoted P. boryanum dominance, improved 1 h-settleability by >20% and increased biomass productivity by >25% compared with controls that had no recycling. With regard to the improved harvestability, of particular interest was that recycling the liquid fraction alone caused a similar improvement in settleability as recycling the solid fraction. This may be due to the presence of extracellular polymeric substances in the liquid fraction. While there are many possible mechanisms that could account for the increased productivity with algal recycling, all but two were systematically eliminated: (i) the mean cell residence time was extended thereby increasing the algal concentration and more fully utilizing the incident sunlight and, (ii) the relative proportions of algal growth stages (which have different specific growth rates) was changed, resulting in a net increase in the overall growth rate of the culture. PMID:23866138

  12. Algal biomass production and wastewater treatment in high rate algal ponds receiving disinfected effluent.

    PubMed

    Santiago, Aníbal Fonseca; Calijuri, Maria Lucia; Assemany, Paula Peixoto; Calijuri, Maria do Carmo; dos Reis, Alberto José Delgado

    2013-01-01

    Algal biomass production associated with wastewater is usually carried out in high rate algal ponds (HRAPs), which are concomitantly used in the treatment of such effluent. However, most types of wastewater have high levels of bacteria that can inhibit the growth of algal biomass by competing for space and nutrients. The objective of this study was to assess the influence of ultraviolet (UV) pre-disinfection on the performance of HRAPs used for wastewater treatment and algal biomass production. Two HRAPs were tested: one received effluent from an upflow anaerobic sludge blanket (UASB) reactor- HRAP -and the second received UASB effluent pre-disinfected by UV radiation-(UV)HRAP. Physical, chemical and microbiological parameters were monitored, as well as algal biomass productivity and daily pH and dissolved oxygen (DO) variation. The (UV)HRAP presented highest DO and pH values, as well as greater percentage of chlorophyll a in the biomass, which indicates greater algal biomass productivity. The average percentages of chlorophyll a found in the biomass obtained from the HRAP and the (UV)HRAP were 0.95 +/- 0.65% and 1.58 +/- 0.65%, respectively. However, total biomass productivity was greater in the HRAP (11.4 gVSSm(-2) day(-1)) compared with the (UV)HRAP (9.3 gVSSm(-2) day(-1)). Mean pH values were 7.7 +/- 0.7 in the HRAP and 8.1 +/- 1.0 in the (UV)HRAP, and mean values of DO percent saturation were 87 +/- 26% and 112 +/- 31% for the HRAP and the (UV)HRAP, respectively. Despite these differences, removal efficiencies of organic carbon, chemical oxygen demand, ammoniacal nitrogen and soluble phosphorus were statistically equal at the 5% significance level.

  13. Control of algal production in a high rate algal pond: investigation through batch and continuous experiments.

    PubMed

    Derabe Maobe, H; Onodera, M; Takahashi, M; Satoh, H; Fukazawa, T

    2014-01-01

    For decades, arid and semi-arid regions in Africa have faced issues related to water availability for drinking, irrigation and livestock purposes. To tackle these issues, a laboratory scale greywater treatment system based on high rate algal pond (HRAP) technology was investigated in order to guide the operation of the pilot plant implemented in the 2iE campus in Ouagadougou (Burkina Faso). Because of the high suspended solids concentration generally found in effluents of this system, the aim of this study is to improve the performance of HRAPs in term of algal productivity and removal. To determine the selection mechanism of self-flocculated algae, three sets of sequencing batch reactors (SBRs) and three sets of continuous flow reactors (CFRs) were operated. Despite operation with the same solids retention time and the similarity of the algal growth rate found in these reactors, the algal productivity was higher in the SBRs owing to the short hydraulic retention time of 10 days in these reactors. By using a volume of CFR with twice the volume of our experimental CFRs, the algal concentration can be controlled during operation under similar physical conditions in both reactors. PMID:24960016

  14. Algal productivity modeling: a step toward accurate assessments of full-scale algal cultivation.

    PubMed

    Béchet, Quentin; Chambonnière, Paul; Shilton, Andy; Guizard, Guillaume; Guieysse, Benoit

    2015-05-01

    A new biomass productivity model was parameterized for Chlorella vulgaris using short-term (<30 min) oxygen productivities from algal microcosms exposed to 6 light intensities (20-420 W/m(2)) and 6 temperatures (5-42 °C). The model was then validated against experimental biomass productivities recorded in bench-scale photobioreactors operated under 4 light intensities (30.6-74.3 W/m(2)) and 4 temperatures (10-30 °C), yielding an accuracy of ± 15% over 163 days of cultivation. This modeling approach addresses major challenges associated with the accurate prediction of algal productivity at full-scale. Firstly, while most prior modeling approaches have only considered the impact of light intensity on algal productivity, the model herein validated also accounts for the critical impact of temperature. Secondly, this study validates a theoretical approach to convert short-term oxygen productivities into long-term biomass productivities. Thirdly, the experimental methodology used has the practical advantage of only requiring one day of experimental work for complete model parameterization. The validation of this new modeling approach is therefore an important step for refining feasibility assessments of algae biotechnologies.

  15. Algal productivity modeling: a step toward accurate assessments of full-scale algal cultivation.

    PubMed

    Béchet, Quentin; Chambonnière, Paul; Shilton, Andy; Guizard, Guillaume; Guieysse, Benoit

    2015-05-01

    A new biomass productivity model was parameterized for Chlorella vulgaris using short-term (<30 min) oxygen productivities from algal microcosms exposed to 6 light intensities (20-420 W/m(2)) and 6 temperatures (5-42 °C). The model was then validated against experimental biomass productivities recorded in bench-scale photobioreactors operated under 4 light intensities (30.6-74.3 W/m(2)) and 4 temperatures (10-30 °C), yielding an accuracy of ± 15% over 163 days of cultivation. This modeling approach addresses major challenges associated with the accurate prediction of algal productivity at full-scale. Firstly, while most prior modeling approaches have only considered the impact of light intensity on algal productivity, the model herein validated also accounts for the critical impact of temperature. Secondly, this study validates a theoretical approach to convert short-term oxygen productivities into long-term biomass productivities. Thirdly, the experimental methodology used has the practical advantage of only requiring one day of experimental work for complete model parameterization. The validation of this new modeling approach is therefore an important step for refining feasibility assessments of algae biotechnologies. PMID:25502920

  16. Full-scale validation of a model of algal productivity.

    PubMed

    Béchet, Quentin; Shilton, Andy; Guieysse, Benoit

    2014-12-01

    While modeling algal productivity outdoors is crucial to assess the economic and environmental performance of full-scale cultivation, most of the models hitherto developed for this purpose have not been validated under fully relevant conditions, especially with regard to temperature variations. The objective of this study was to independently validate a model of algal biomass productivity accounting for both light and temperature and constructed using parameters experimentally derived using short-term indoor experiments. To do this, the accuracy of a model developed for Chlorella vulgaris was assessed against data collected from photobioreactors operated outdoor (New Zealand) over different seasons, years, and operating conditions (temperature-control/no temperature-control, batch, and fed-batch regimes). The model accurately predicted experimental productivities under all conditions tested, yielding an overall accuracy of ±8.4% over 148 days of cultivation. For the purpose of assessing the feasibility of full-scale algal cultivation, the use of the productivity model was therefore shown to markedly reduce uncertainty in cost of biofuel production while also eliminating uncertainties in water demand, a critical element of environmental impact assessments. Simulations at five climatic locations demonstrated that temperature-control in outdoor photobioreactors would require tremendous amounts of energy without considerable increase of algal biomass. Prior assessments neglecting the impact of temperature variations on algal productivity in photobioreactors may therefore be erroneous.

  17. Hybrid life-cycle assessment of algal biofuel production.

    PubMed

    Malik, Arunima; Lenzen, Manfred; Ralph, Peter J; Tamburic, Bojan

    2015-05-01

    The objective of this work is to establish whether algal bio-crude production is environmentally, economically and socially sustainable. To this end, an economic multi-regional input-output model of Australia was complemented with engineering process data on algal bio-crude production. This model was used to undertake hybrid life-cycle assessment for measuring the direct, as well as indirect impacts of producing bio-crude. Overall, the supply chain of bio-crude is more sustainable than that of conventional crude oil. The results indicate that producing 1 million tonnes of bio-crude will generate almost 13,000 new jobs and 4 billion dollars' worth of economic stimulus. Furthermore, bio-crude production will offer carbon sequestration opportunities as the production process is net carbon-negative.

  18. Hybrid life-cycle assessment of algal biofuel production.

    PubMed

    Malik, Arunima; Lenzen, Manfred; Ralph, Peter J; Tamburic, Bojan

    2015-05-01

    The objective of this work is to establish whether algal bio-crude production is environmentally, economically and socially sustainable. To this end, an economic multi-regional input-output model of Australia was complemented with engineering process data on algal bio-crude production. This model was used to undertake hybrid life-cycle assessment for measuring the direct, as well as indirect impacts of producing bio-crude. Overall, the supply chain of bio-crude is more sustainable than that of conventional crude oil. The results indicate that producing 1 million tonnes of bio-crude will generate almost 13,000 new jobs and 4 billion dollars' worth of economic stimulus. Furthermore, bio-crude production will offer carbon sequestration opportunities as the production process is net carbon-negative. PMID:25465782

  19. Recent progress and future challenges in algal biofuel production

    PubMed Central

    Shurin, Jonathan B.; Burkart, Michael D.; Mayfield, Stephen P.

    2016-01-01

    Modern society is fueled by fossil energy produced millions of years ago by photosynthetic organisms. Cultivating contemporary photosynthetic producers to generate energy and capture carbon from the atmosphere is one potential approach to sustaining society without disrupting the climate. Algae, photosynthetic aquatic microorganisms, are the fastest growing primary producers in the world and can therefore produce more energy with less land, water, and nutrients than terrestrial plant crops. We review recent progress and challenges in developing bioenergy technology based on algae. A variety of high-value products in addition to biofuels can be harvested from algal biomass, and these may be key to developing algal biotechnology and realizing the commercial potential of these organisms. Aspects of algal biology that differentiate them from plants demand an integrative approach based on genetics, cell biology, ecology, and evolution. We call for a systems approach to research on algal biotechnology rooted in understanding their biology, from the level of genes to ecosystems, and integrating perspectives from physical, chemical, and social sciences to solve one of the most critical outstanding technological problems. PMID:27781084

  20. Phenolic content and antioxidant capacity in algal food products.

    PubMed

    Machu, Ludmila; Misurcova, Ladislava; Ambrozova, Jarmila Vavra; Orsavova, Jana; Mlcek, Jiri; Sochor, Jiri; Jurikova, Tunde

    2015-01-01

    The study objective was to investigate total phenolic content using Folin-Ciocalteu's method, to assess nine phenols by HPLC, to determine antioxidant capacity of the water soluble compounds (ACW) by a photochemiluminescence method, and to calculate the correlation coefficients in commercial algal food products from brown (Laminaria japonica, Eisenia bicyclis, Hizikia fusiformis, Undaria pinnatifida) and red (Porphyra tenera, Palmaria palmata) seaweed, green freshwater algae (Chlorella pyrenoidosa), and cyanobacteria (Spirulina platensis). HPLC analysis showed that the most abundant phenolic compound was epicatechin. From spectrophotometry and ACW determination it was evident that brown seaweed Eisenia bicyclis was the sample with the highest phenolic and ACW values (193 mg·g-1 GAE; 7.53 µmol AA·g-1, respectively). A linear relationship existed between ACW and phenolic contents (r = 0.99). Some algal products seem to be promising functional foods rich in polyphenols. PMID:25587787

  1. Turbulence and nutrient interactions that control benthic algal production in an engineered cultivation raceway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flow turbulence can be a controlling factor to the growth of benthic algae, but few studies have quantified this relationship in engineered cultivation systems. Experiments were performed to understand the limiting role of turbulence to algal productivity in an algal turf scrubber for benthic algal...

  2. Algal turf scrubber (ATS) floways on the Great Wicomico River, Chesapeake Bay: productivity, algal community structure, substrate and chemistry(1).

    PubMed

    Adey, Walter H; Laughinghouse, H Dail; Miller, John B; Hayek, Lee-Ann C; Thompson, Jesse G; Bertman, Steven; Hampel, Kristin; Puvanendran, Shanmugam

    2013-06-01

    Two Algal Turf Scrubber (ATS) units were deployed on the Great Wicomico River (GWR) for 22 months to examine the role of substrate in increasing algal productivity and nutrient removal. The yearly mean productivity of flat ATS screens was 15.4 g · m(-2)  · d(-1) . This was elevated to 39.6 g · m(-2)  · d(-1) with a three-dimensional (3-D) screen, and to 47.7 g · m(-2)  · d(-1) by avoiding high summer harvest temperatures. These methods enhanced nutrient removal (N, P) in algal biomass by 3.5 times. Eighty-six algal taxa (Ochrophyta [diatoms], Chlorophyta [green algae], and Cyan-obacteria [blue-green algae]) self-seeded from the GWR and demonstrated yearly cycling. Silica (SiO2 ) content of the algal biomass ranged from 30% to 50% of total biomass; phosphorus, nitrogen, and carbon content of the total algal biomass ranged from 0.15% to 0.21%, 2.13% to 2.89%, and 20.0% to 25.7%, respectively. Carbohydrate content (at 10%-25% of AFDM) was dominated by glucose. Lipids (fatty acid methyl ester; FAMEs) ranged widely from 0.5% to 9% AFDM, with Omega-3 fatty acids a consistent component. Mathematical modeling of algal produ-ctivity as a function of temperature, light, and substrate showed a proportionality of 4:3:3, resp-ectively. Under landscape ATS operation, substrate manipulation provides a considerable opportunity to increase ATS productivity, water quality amelioration, and biomass coproduction for fertilizers, fermentation energy, and omega-3 products. Based on the 3-D prod-uctivity and algal chemical composition demonstrated, ATS systems used for nonpoint source water treat-ment can produce ethanol (butanol) at 5.8× per unit area of corn, and biodiesel at 12.0× per unit area of soy beans (agricultural production US). PMID:27007038

  3. Evaluation of extracellular products and mutagenicity in cyanobacteria cultures separated from a eutrophic reservoir.

    PubMed

    Huang, Winn-Jung; Lai, Chun-Hsi; Cheng, Yung-Ling

    2007-05-15

    The algal extracellular products (ECPs) in three cultures of cyanobacteria species (Anabaena, Microcystis, and Oscillatoria) dominating the eutrophic reservoir populations and their toxins have been investigated in the present work. Using gas chromatography coupled with high-resolution electron-impact mass spectrometry (GC/EI-MS) and high performance anion-exchange chromatography (HPAEC) techniques, more than 20 compounds were found in the algal culture (including cells and filtrates) extracts. The main identified ECPs were classified to polysaccharides, hydrocarbons, and aldehydes. Odor causing substances such as trans-1,10-dimethyl-trans-9-decalol (geosmin) and 2-methylisoborneol (2-MIB)were also found in the algal cultures. The potential mutagenicity of the algal suspensions was also studied with the Ames test. The organic extracts of the algal suspension from the axenic cultures were mutagenicity in TA98 without S9 mix and in TA100 with and without S9 mix. The results indicate that the ECPs of three algae species dominating the eutrophic reservoir were mutagenic clearly in the bacterial test. PMID:17391736

  4. Effect of centrifugation on water recycling and algal growth to enable algae biodiesel production.

    PubMed

    Igou, Thomas; Van Ginkel, Steven W; Penalver-Argueso, Patricia; Fu, Hao; Doi, Shusuke; Narode, Asmita; Cheruvu, Sarasija; Zhang, Qian; Hassan, Fariha; Woodruff, Frazier; Chen, Yongsheng

    2014-12-01

    The latest research shows that algal biofuels, at the production levels mandated in the Energy Independence and Security Act of 2007, will place significant demands on water and compete with agriculture meant for food production. Thus, there is a great need to recycle water while producing algal biofuels. This study shows that when using a synthetic medium, soluble algal products, bacteria, and other inhibitors can be removed by centrifugation and enable water recycling. Average water recovery reached 84% and water could be recycled at least 10 times without reducing algal growth.

  5. Oxygen sensitivity of algal H{sub 2}-production

    SciTech Connect

    Ghirardi, M.L.; Seibert, M.; Togasaki, R.K.

    1997-12-31

    Photoproduction of H{sub 2} by green algae utilizes electrons originating from the photosynthetic oxidation of water and does not require metabolic intermediates. However, algal hydrogenases are extremely sensitive to O{sub 2}, which limits their usefulness in future commercial H{sub 2}-production systems. We designed an experimental technique for the selection of O{sub 2}tolerant, H{sub 2}-producing variants of Chlamydomonas reinhardtii based on the ability of wild-type cells to survive a short (20 min) exposure to metronidazole in the presence of controlled concentrations of O{sub 2}. The number of survivors depends on the metronidazole concentration, light intensity, preinduction of the hydrogenase, and the presence or absence of O{sub 2}. Finally, we demonstrate that some of the selected survivors in fact exhibit H{sub 2}-production capacity that is less sensitive to O{sub 2} than the original wild-type population. 17 refs., 1 tab.

  6. Strategies for optimizing algal biology for enhanced biomass production

    SciTech Connect

    Barry, Amanda N.; Starkenburg, Shawn R.; Sayre, Richard T.

    2015-02-02

    One of the most environmentally sustainable ways to produce high-energy density (oils) feed stocks for the production of liquid transportation fuels is from biomass. Photosynthetic carbon capture combined with biomass combustion (point source) and subsequent carbon capture and sequestration has also been proposed in the intergovernmental panel on climate change report as one of the most effective and economical strategies to remediate atmospheric greenhouse gases. To maximize photosynthetic carbon capture efficiency and energy-return-on-investment, we must develop biomass production systems that achieve the greatest yields with the lowest inputs. Numerous studies have demonstrated that microalgae have among the greatest potentials for biomass production. This is in part due to the fact that all alga cells are photoautotrophic, they have active carbon concentrating mechanisms to increase photosynthetic productivity, and all the biomass is harvestable unlike plants. All photosynthetic organisms, however, convert only a fraction of the solar energy they capture into chemical energy (reduced carbon or biomass). To increase aerial carbon capture rates and biomass productivity, it will be necessary to identify the most robust algal strains and increase their biomass production efficiency often by genetic manipulation. We review recent large-scale efforts to identify the best biomass producing strains and metabolic engineering strategies to improve aerial productivity. In addition, these strategies include optimization of photosynthetic light-harvesting antenna size to increase energy capture and conversion efficiency and the potential development of advanced molecular breeding techniques. To date, these strategies have resulted in up to twofold increases in biomass productivity.

  7. In vivo Reconstitution of Algal Triacylglycerol Production in Saccharomyces cerevisiae.

    PubMed

    Hung, Chun-Hsien; Kanehara, Kazue; Nakamura, Yuki

    2016-01-01

    The current fascination with algal biofuel production stems from a high lipid biosynthetic capacity and little conflict with land plant cultivation. However, the mechanisms which enable algae to accumulate massive oil remain elusive. An enzyme for triacylglycerol (TAG) biosynthesis in Chlamydomonas reinhardtii, CrDGTT2, can produce a large amount of TAG when expressed in yeast or higher plants, suggesting a unique ability of CrDGTT2 to enhance oil production in a heterologous system. Here, we performed metabolic engineering in Saccharomyces cerevisiae by taking advantage of CrDGTT2. We suppressed membrane phospholipid biosynthesis at the log phase by mutating OPI3, enhanced TAG biosynthetic pathway at the stationary phase by overexpressing PAH1 and CrDGTT2, and suppressed TAG hydrolysis on growth resumption from the stationary phase by knocking out DGK1. The resulting engineered yeast cells accumulated about 70-fold of TAG compared with wild type cells. Moreover, TAG production was sustainable. Our results demonstrated the enhanced and sustainable TAG production in the yeast synthetic platform. PMID:26913021

  8. Strategies for optimizing algal biology for enhanced biomass production

    DOE PAGES

    Barry, Amanda N.; Starkenburg, Shawn R.; Sayre, Richard T.

    2015-02-02

    One of the most environmentally sustainable ways to produce high-energy density (oils) feed stocks for the production of liquid transportation fuels is from biomass. Photosynthetic carbon capture combined with biomass combustion (point source) and subsequent carbon capture and sequestration has also been proposed in the intergovernmental panel on climate change report as one of the most effective and economical strategies to remediate atmospheric greenhouse gases. To maximize photosynthetic carbon capture efficiency and energy-return-on-investment, we must develop biomass production systems that achieve the greatest yields with the lowest inputs. Numerous studies have demonstrated that microalgae have among the greatest potentials formore » biomass production. This is in part due to the fact that all alga cells are photoautotrophic, they have active carbon concentrating mechanisms to increase photosynthetic productivity, and all the biomass is harvestable unlike plants. All photosynthetic organisms, however, convert only a fraction of the solar energy they capture into chemical energy (reduced carbon or biomass). To increase aerial carbon capture rates and biomass productivity, it will be necessary to identify the most robust algal strains and increase their biomass production efficiency often by genetic manipulation. We review recent large-scale efforts to identify the best biomass producing strains and metabolic engineering strategies to improve aerial productivity. In addition, these strategies include optimization of photosynthetic light-harvesting antenna size to increase energy capture and conversion efficiency and the potential development of advanced molecular breeding techniques. To date, these strategies have resulted in up to twofold increases in biomass productivity.« less

  9. Production of biofuel using molluscan pseudofeces derived from algal cells

    DOEpatents

    Das, Keshav C.; Chinnasamy, Senthil; Shelton, James; Wilde, Susan B.; Haynie, Rebecca S.; Herrin, James A.

    2012-08-28

    Embodiments of the present disclosure provide for novel strategies to harvest algal lipids using mollusks which after feeding algae from the growth medium can convert algal lipids into their biomass or excrete lipids in their pseudofeces which makes algae harvesting energy efficient and cost effective. The bioconverter, filter-feeding mollusks and their pseudofeces can be harvested and converted to biocrude using an advanced thermochemical liquefaction technology. Methods, systems, and materials are disclosed for the harvest and isolation of algal lipids from the mollusks, molluscan feces and molluscan pseudofeces.

  10. Bioreactor technology for production of valuable algal products

    NASA Astrophysics Data System (ADS)

    Liu, Guo-Cai; Cao, Ying

    1998-03-01

    Bioreactor technology has long been employed for the production of various (mostly cheap) food and pharmaceutical products. More recently, research has been mainly focused on the development of novel bioreactor technology for the production of high—value products. This paper reports the employment of novel bioreactor technology for the production of high-value biomass and metabolites by microalgae. These high-value products include microalgal biomass as health foods, pigments including phycocyanin and carotenoids, and polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid. The processes involved include heterotrophic and mixotrophic cultures using organic substrates as the carbon source. We have demonstrated that these bioreactor cultivation systems are particularly suitable for the production of high-value products from various microalgae. These cultivation systems can be further modified to improve cell densities and productivities by using high cell density techniques such as fed-batch and membrane cell recycle systems. For most of the microalgae investigated, the maximum cell concentrations obtained using these bioreactor systems in our laboratories are much higher than any so far reported in the literature.

  11. Mass cultivation of various algal species and their evaluation as a potential candidate for lipid production.

    PubMed

    Sharif, Nadia; Munir, Neelma; Saleem, Faiza; Aslam, Farheen; Naz, Shagufta

    2015-01-01

    Microalgae have been proposed as a promising source for biodiesel production. Focusing on algal strains for biodiesel production, efforts should be made to search new strains. Experiments were carried out to investigate the effects of growth parameters (nutrients, pH, light, aeration and temperature) and the oil percentage of eight algal strains (Chlorella sp., Cladophora sp., Hydrodictylium sp., Oedogonium sp., Oscillatoria sp., Spirogyra sp., Stigeocolonium sp., Ulothrix sp.). Results show that 6.5-7.5 is the optimum pH for the growth of all algal species. Temperature showed a greater variation (25°40°C). Ulothrix sp. gave more biomass productivity and is the most suitable strain for biodiesel production due to higher oil percentage (62%). Least biomass production was observed for Stigeocolonium sp. and least oil content was obtained from Hydrodictylium sp. It was observed that among these eight algal strains for biodiesel production, Ulothrix and Chlorella are the most promising algae species.

  12. Impact of Microalgae-Bacteria Interactions on the Production of Algal Biomass and Associated Compounds

    PubMed Central

    Fuentes, Juan Luis; Garbayo, Inés; Cuaresma, María; Montero, Zaida; González-del-Valle, Manuel; Vílchez, Carlos

    2016-01-01

    A greater insight on the control of the interactions between microalgae and other microorganisms, particularly bacteria, should be useful for enhancing the efficiency of microalgal biomass production and associated valuable compounds. Little attention has been paid to the controlled utilization of microalgae-bacteria consortia. However, the studies of microalgal-bacterial interactions have revealed a significant impact of the mutualistic or parasitic relationships on algal growth. The algal growth, for instance, has been shown to be enhanced by growth promoting factors produced by bacteria, such as indole-3-acetic acid. Vitamin B12 produced by bacteria in algal cultures and bacterial siderophores are also known to be involved in promoting faster microalgal growth. More interestingly, enhancement in the intracellular levels of carbohydrates, lipids and pigments of microalgae coupled with algal growth stimulation has also been reported. In this sense, massive algal production might occur in the presence of bacteria, and microalgae-bacteria interactions can be beneficial to the massive production of microalgae and algal products. This manuscript reviews the recent knowledge on the impact of the microalgae-bacteria interactions on the production of microalgae and accumulation of valuable compounds, with an emphasis on algal species having application in aquaculture. PMID:27213407

  13. Environmental indicators for sustainable production of algal biofuels

    SciTech Connect

    Efroymson, Rebecca A.; Dale, Virginia H.

    2014-10-01

    For analyzing sustainability of algal biofuels, we identify 16 environmental indicators that fall into six categories: soil quality, water quality and quantity, air quality, greenhouse gas emissions, biodiversity, and productivity. Indicators are selected to be practical, widely applicable, predictable in response, anticipatory of future changes, independent of scale, and responsive to management. Major differences between algae and terrestrial plant feedstocks, as well as their supply chains for biofuel, are highlighted, for they influence the choice of appropriate sustainability indicators. Algae strain selection characteristics do not generally affect which indicators are selected. The use of water instead of soil as the growth medium for algae determines the higher priority of water- over soil-related indicators. The proposed set of environmental indicators provides an initial checklist for measures of biofuel sustainability but may need to be modified for particular contexts depending on data availability, goals of the stakeholders, and financial constraints. Ultimately, use of these indicators entails defining sustainability goals and targets in relation to stakeholder values in a particular context and can lead to improved management practices.

  14. Environmental indicators for sustainable production of algal biofuels

    DOE PAGES

    Efroymson, Rebecca A.; Dale, Virginia H.

    2014-10-01

    For analyzing sustainability of algal biofuels, we identify 16 environmental indicators that fall into six categories: soil quality, water quality and quantity, air quality, greenhouse gas emissions, biodiversity, and productivity. Indicators are selected to be practical, widely applicable, predictable in response, anticipatory of future changes, independent of scale, and responsive to management. Major differences between algae and terrestrial plant feedstocks, as well as their supply chains for biofuel, are highlighted, for they influence the choice of appropriate sustainability indicators. Algae strain selection characteristics do not generally affect which indicators are selected. The use of water instead of soil as themore » growth medium for algae determines the higher priority of water- over soil-related indicators. The proposed set of environmental indicators provides an initial checklist for measures of biofuel sustainability but may need to be modified for particular contexts depending on data availability, goals of the stakeholders, and financial constraints. Ultimately, use of these indicators entails defining sustainability goals and targets in relation to stakeholder values in a particular context and can lead to improved management practices.« less

  15. Extracellular polysaccharide production by thraustochytrid protists.

    PubMed

    Jain, Ruchi; Raghukumar, Seshagiri; Tharanathan, R; Bhosle, N B

    2005-01-01

    Four strains of marine stramenopilan protists, the thraustochytrids, were studied for their ability to produce extracellular polysaccharides (EPSs). Observations by light and scanning electron microscopy revealed the production of a matrix of EPS around groups of cells in stationary cultures. EPS in shake culture filtrates ranged from 0.3 to 1.1 g/L. EPS production, which was studied in greater detail in 2 isolates, SC-1 and CW1, increased with age of cultures, reaching a peak in the stationary phase. Anion exchange chromatography yielded a single fraction of the EPS of both species. The EPS contained 39% to 53% sugars, besides proteins, lipids, uronic acids, and sulfates. Molecular weight of the EPS produced by SC-1 was approximately 94 kDa, and that of CW1, 320 kDa. Glucose formed the major component in the EPS of both isolates-galactose, mannose, and arabinose being the other components. Cultures of both isolates survived air-drying up to a period of 96 hours, suggesting a role for EPS in preventing desiccation of cells.

  16. Enhanced production of green tide algal biomass through additional carbon supply.

    PubMed

    de Paula Silva, Pedro H; Paul, Nicholas A; de Nys, Rocky; Mata, Leonardo

    2013-01-01

    Intensive algal cultivation usually requires a high flux of dissolved inorganic carbon (Ci) to support productivity, particularly for high density algal cultures. Carbon dioxide (CO2) enrichment can be used to overcome Ci limitation and enhance productivity of algae in intensive culture, however, it is unclear whether algal species with the ability to utilise bicarbonate (HCO3 (-)) as a carbon source for photosynthesis will benefit from CO2 enrichment. This study quantified the HCO3 (-) affinity of three green tide algal species, Cladophora coelothrix, Cladophora patentiramea and Chaetomorpha linum, targeted for biomass and bioenergy production. Subsequently, we quantified productivity and carbon, nitrogen and ash content in response to CO2 enrichment. All three species had similar high pH compensation points (9.7-9.9), and grew at similar rates up to pH 9, demonstrating HCO3 (-) utilization. Algal cultures enriched with CO2 as a carbon source had 30% more total Ci available, supplying twenty five times more CO2 than the control. This higher Ci significantly enhanced the productivity of Cladophora coelothrix (26%), Chaetomorpha linum (24%) and to a lesser extent for Cladophora patentiramea (11%), compared to controls. We demonstrated that supplying carbon as CO2 can enhance the productivity of targeted green tide algal species under intensive culture, despite their clear ability to utilise HCO3 (-).

  17. Enhanced Production of Green Tide Algal Biomass through Additional Carbon Supply

    PubMed Central

    de Paula Silva, Pedro H.; Paul, Nicholas A.; de Nys, Rocky; Mata, Leonardo

    2013-01-01

    Intensive algal cultivation usually requires a high flux of dissolved inorganic carbon (Ci) to support productivity, particularly for high density algal cultures. Carbon dioxide (CO2) enrichment can be used to overcome Ci limitation and enhance productivity of algae in intensive culture, however, it is unclear whether algal species with the ability to utilise bicarbonate (HCO3−) as a carbon source for photosynthesis will benefit from CO2 enrichment. This study quantified the HCO3− affinity of three green tide algal species, Cladophora coelothrix, Cladophora patentiramea and Chaetomorpha linum, targeted for biomass and bioenergy production. Subsequently, we quantified productivity and carbon, nitrogen and ash content in response to CO2 enrichment. All three species had similar high pH compensation points (9.7–9.9), and grew at similar rates up to pH 9, demonstrating HCO3− utilization. Algal cultures enriched with CO2 as a carbon source had 30% more total Ci available, supplying twenty five times more CO2 than the control. This higher Ci significantly enhanced the productivity of Cladophora coelothrix (26%), Chaetomorpha linum (24%) and to a lesser extent for Cladophora patentiramea (11%), compared to controls. We demonstrated that supplying carbon as CO2 can enhance the productivity of targeted green tide algal species under intensive culture, despite their clear ability to utilise HCO3−. PMID:24324672

  18. Algal extracellular release in river-floodplain dissolved organic matter: response of extracellular enzymatic activity during a post-flood period

    PubMed Central

    Sieczko, Anna; Maschek, Maria; Peduzzi, Peter

    2015-01-01

    River-floodplain systems are susceptible to rapid hydrological events. Changing hydrological connectivity of the floodplain generates a broad range of conditions, from lentic to lotic. This creates a mixture of allochthonously and autochthonously derived dissolved organic matter (DOM). Autochthonous DOM, including photosynthetic extracellular release (PER), is an important source supporting bacterial secondary production (BSP). Nonetheless, no details are available regarding microbial extracellular enzymatic activity (EEA) as a response to PER under variable hydrological settings in river-floodplain systems. To investigate the relationship between bacterial and phytoplankton components, we therefore used EEA as a tool to track the microbial response to non-chromophoric, but reactive and ecologically important DOM. The study was conducted in three floodplain subsystems with distinct hydrological regimes (Danube Floodplain National Park, Austria). The focus was on the post-flood period. Enhanced %PER (up to 48% of primary production) in a hydrologically isolated subsystem was strongly correlated with β-glucosidase, which was related to BSP. This shows that—in disconnected floodplain backwaters with high terrestrial input—BSP can also be driven by autochthonous carbon sources (PER). In a semi-isolated section, in the presence of fresh labile material from primary producers, enhanced activity of phenol oxidase was observed. In frequently flooded river-floodplain systems, BSP was mainly driven by enzymatic degradation of particulate primary production. Our research demonstrates that EEA measurements are an excellent tool to describe the coupling between bacteria and phytoplankton, which cannot be deciphered when focusing solely on chromophoric DOM. PMID:25741326

  19. Advancing Commercialization of Algal Biofuels Through Increased Biomass Productivity and Technology Integration

    SciTech Connect

    Bai, Xuemei; Sabarsky, Martin

    2013-09-30

    Cellana is a leading developer of algae-based bioproducts, and its pre-commercial production of marine microalgae takes place at Cellana?s Kona Demonstration Facility (KDF) in Hawaii. KDF is housing more than 70 high-performing algal strains for different bioproducts, of which over 30 have been grown outside at scale. So far, Cellana has produced more than 10 metric tons of algal biomass for the development of biofuels, animal feed, and high-value nutraceuticals. Cellana?s ALDUO algal cultivation technology allows Cellana to grow non-extremophile algal strains at large scale with no contamination disruptions. Cellana?s research and production at KDF have addressed three major areas that are crucial for the commercialization of algal biofuels: yield improvement, cost reduction, and the overall economics. Commercially acceptable solutions have been developed and tested for major factors limiting areal productivity of algal biomass and lipids based on years of R&D work conducted at KDF. Improved biomass and lipid productivity were achieved through strain improvement, culture management strategies (e.g., alleviation of self-shading, de-oxygenation, and efficient CO2 delivery), and technical advancement in downstream harvesting technology. Cost reduction was achieved through optimized CO2 delivery system, flue gas utilization technology, and energy-efficient harvesting technology. Improved overall economics was achieved through a holistic approach by integration of high-value co-products in the process, in addition to yield improvements and cost reductions.

  20. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid- and Carbohydrate-Derived Fuel Products

    SciTech Connect

    Davis, R.; Kinchin, C.; Markham, J.; Tan, E.; Laurens, L.; Sexton, D.; Knorr, D.; Schoen, P.; Lukas, J.

    2014-09-01

    Beginning in 2013, NREL began transitioning from the singular focus on ethanol to a broad slate of products and conversion pathways, ultimately to establish similar benchmarking and targeting efforts. One of these pathways is the conversion of algal biomass to fuels via extraction of lipids (and potentially other components), termed the 'algal lipid upgrading' or ALU pathway. This report describes in detail one potential ALU approach based on a biochemical processing strategy to selectively recover and convert select algal biomass components to fuels, namely carbohydrates to ethanol and lipids to a renewable diesel blendstock (RDB) product. The overarching process design converts algal biomass delivered from upstream cultivation and dewatering (outside the present scope) to ethanol, RDB, and minor coproducts, using dilute-acid pretreatment, fermentation, lipid extraction, and hydrotreating.

  1. Research, development, and demonstration of algal production raceway (APR) systems for the production of hydrocarbon resources

    SciTech Connect

    Laws, E.A.

    1984-02-01

    A fractional factorial experimental design was used to determine the maximum production and photosynthetic efficiency that could be achieved in shallow algal mass culture systems (SAMCS) of the marine diatom Phaeodactylum tricornutum. Dilution rate and CO/sub 2/ supply were found to be the most important system parameters. Maximum production was found to be about 25 g dry wt m/sup -2/d/sup -1/. This production corresponded to a photosynthetic efficiency of 5.6%. These figures are 50 to 100% better than the production rates achieved in earlier P. tricornutum cultures using conventional culture techniques. The results are consistent with a theoretical model of the impact of the flashing light effect on algal mass culture production. This model predicts that at the typical irradiances in Hawaii, full utilization of the flashing light effect should enhance production by 70% to over 200%. It was concluded that the use of foil arrays in the experimental flume creates systematic vertical mixing on a time scale suitable for utilizing the flashing light effect. Production of P. tricornutum culture is probably limited by temperature. P. tricornutum cannot survive at temperatures in excess of 25/sup 0/C in outdoor mass cultures. Growth of mesophilic species in the temperature range 30 to 35/sup 0/C may well result in even higher production than that achieved with P. tricornutum.

  2. Geographic analysis of the feasibility of collocating algal biomass production with wastewater treatment plants.

    PubMed

    Fortier, Marie-Odile P; Sturm, Belinda S M

    2012-10-16

    Resource demand analyses indicate that algal biodiesel production would require unsustainable amounts of freshwater and fertilizer supplies. Alternatively, municipal wastewater effluent can be used, but this restricts production of algae to areas near wastewater treatment plants (WWTPs), and to date, there has been no geospatial analysis of the feasibility of collocating large algal ponds with WWTPs. The goals of this analysis were to determine the available areas by land cover type within radial extents (REs) up to 1.5 miles from WWTPs; to determine the limiting factor for algal production using wastewater; and to investigate the potential algal biomass production at urban, near-urban, and rural WWTPs in Kansas. Over 50% and 87% of the land around urban and rural WWTPs, respectively, was found to be potentially available for algal production. The analysis highlights a trade-off between urban WWTPs, which are generally land-limited but have excess wastewater effluent, and rural WWTPs, which are generally water-limited but have 96% of the total available land. Overall, commercial-scale algae production collocated with WWTPs is feasible; 29% of the Kansas liquid fuel demand could be met with implementation of ponds within 1 mile of all WWTPs and supplementation of water and nutrients when these are limited. PMID:22970803

  3. Wastewater treatment high rate algal ponds (WWT HRAP) for low-cost biofuel production.

    PubMed

    Mehrabadi, Abbas; Craggs, Rupert; Farid, Mohammed M

    2015-05-01

    Growing energy demand and water consumption have increased concerns about energy security and efficient wastewater treatment and reuse. Wastewater treatment high rate algal ponds (WWT HRAPs) are a promising technology that could help solve these challenges concurrently where climate is favorable. WWT HRAPs have great potential for biofuel production as a by-product of WWT, since the costs of algal cultivation and harvest for biofuel production are covered by the wastewater treatment function. Generally, 800-1400 GJ/ha/year energy (average biomass energy content: 20 GJ/ton; HRAP biomass productivity: 40-70 tons/ha/year) can be produced in the form of harvestable biomass from WWT HRAP which can be used to provide community-level energy supply. In this paper the benefits of WWT HRAPs are compared with conventional mass algal culture systems. Moreover, parameters to effectively increase algal energy content and overall energy production from WWT HRAP are discussed including selection of appropriate algal biomass biofuel conversion pathways.

  4. Light availability may control extracellular phosphatase production in turbid environments.

    PubMed

    Rychtecký, Pavel; Řeháková, Klára; Kozlíková, Eliška; Vrba, Jaroslav

    2015-01-01

    Extracellular phosphatase production by phytoplankton was investigated in the moderately eutrophic Lipno reservoir, Czech Republic during 2009 and 2010. We hypothesized that production of extracellular phosphatases is an additional mechanism of phosphorus acquisition enabling producers to survive rather than to dominate the phytoplankton. Hence, we examined the relationship between light availability and phosphatase production, as light plays an important role in polymictic environments. Bulk phosphatase activity was measured using a common fluorometric assay, and the production of phosphatases was studied using the Fluorescently Labelled Enzyme Activity technique, which enabled direct microscopic detection of phosphatase-positive cells. In total, 29 taxa of phytoplankton were identified during both years. Only 17 taxa from the total number of 29 showed production of extracellular phosphatases. Species dominating the phytoplankton rarely produced extracellular phosphatases. In contrast, taxa exhibiting phosphatase activity were present in low biomass in the phytoplankton assemblage. Moreover, there was a significant relationship between the proportion of phosphatase positive species in samples and the Z(eu):Z(mix) ratio (a proxy of light availability). A laboratory experiment with different light intensities confirmed the influence of light on production of phosphatases. Our seasonal study confirmed that extracellular phosphatase production is common in low-abundance populations but not in dominant taxa of the phytoplankton. It also suggested the importance of sufficient light conditions for the production of extracellular phosphatases.

  5. Enhancing microalgal photosynthesis and productivity in wastewater treatment high rate algal ponds for biofuel production.

    PubMed

    Sutherland, Donna L; Howard-Williams, Clive; Turnbull, Matthew H; Broady, Paul A; Craggs, Rupert J

    2015-05-01

    With microalgal biofuels currently receiving much attention, there has been renewed interest in the combined use of high rate algal ponds (HRAP) for wastewater treatment and biofuel production. This combined use of HRAPs is considered to be an economically feasible option for biofuel production, however, increased microalgal productivity and nutrient removal together with reduced capital costs are needed before it can be commercially viable. Despite HRAPs being an established technology, microalgal photosynthesis and productivity is still limited in these ponds and is well below the theoretical maximum. This paper critically evaluates the parameters that limit microalgal light absorption and photosynthesis in wastewater HRAPs and examines biological, chemical and physical options for improving light absorption and utilisation, with the view of enhancing biomass production and nutrient removal.

  6. Production of Algal-based Biofuel from Non-fresh Water Sources

    NASA Astrophysics Data System (ADS)

    Sun, A. C.; Reno, M. D.

    2008-12-01

    A system dynamics model is developed to assess the availability and feasibility of non-traditional water sources from dairy wastewater, produced water from crude oil production and from coal-bed methane gas extraction for the production of algal-based biofuel. The conceptual framework is based on two locales within New Mexico, the San Juan basin in the northwest and the Permian basin in the southeast, where oil and gas drilling have increased considerably in the last ten years. The simulation framework contains an algal growth module, a dairy module, an oil production module, and a gas production module. Our preliminary investigation indicates a cyclical demand for non-fresh water due to the cyclical nature of algal biomass production and crop evapotranspiration. The wastewater from the dairy industry is not a feasible non-fresh water source because the agricultural water demand for cow's dry feed far exceeds the amount generated at the dairy. The uncertainty associated with the water demand for cow's dry matter intake is the greatest in this model. The oil and gas produced water, ignoring the quality, provides ample supply for water demand in algal biomass production. There remains work to address technical challenges associated with coupling the appropriate non-fresh water source to the local demand.

  7. Primary production of edaphic algal communities in a Mississippi salt marsh

    SciTech Connect

    Sullivan, M.J.; Moncreiff, C.A.

    1988-03-01

    Primary production rates of edaphic algae associated with the sediments beneath four monospecific canopies of vascular plants were determined over an annual cycle in a Mississippi salt marsh. The edaphic algal flora was dominated by small, motile pennate diatoms. Algal production (as measured by /sup 14/C uptake) was generally highest in spring-early summer and lowest in fall. Hourly rates ranged from a low of 1.4 mg C/m/sup 2/ in Juncus roemerianus Scheele to a high of 163 mg C/m/sup 2/ beneath the Scirpus olneyi Gray canopy. Stepwise multiple regressions identified a soil moisture index and chlorophyll a as the best environmental predictors of hourly production; light energy reaching the marsh surface and sediment and air temperature proved of little value. Adding the relative abundances of 33 diatom taxa to the set of independent variables only slightly increased R/sup 2/; however, virtually all variables selected were diatom taxa. R/sup 2/ was only 0.38 for the Spartina alterniflora Loisel. habitat but ranged from 0.70 to 0.87 for the remaining three vascular plant zones. Annual rates of algal production (g C/m/sup 2/) were estimated as follows: Juncus (28), Spartina (57), Distichlis spicata (L.) Greene (88), and Scirpus (151). The ratio of annual edaphic algal production to vascular plant net aerial production (EAP/VPP) was 10-12% for the first three habitats and 61% for Scirpus. Chlorophyll a concentrations, annual algal production rates, and EAP/VPP values were comparable to those determined in Texas, Delaware, and Massachusetts salt marshes but lower than those reported for Georgia and particularly California marshes.

  8. Production of extracellular fatty acid using engineered Escherichia coli

    PubMed Central

    2012-01-01

    Background As an alternative for economic biodiesel production, the microbial production of extracellular fatty acid from renewable resources is receiving more concerns recently, since the separation of fatty acid from microorganism cells is normally involved in a series of energy-intensive steps. Many attempts have been made to construct fatty acid producing strains by targeting genes in the fatty acid biosynthetic pathway, while few studies focused on the cultivation process and the mass transfer kinetics. Results In this study, both strain improvements and cultivation process strategies were applied to increase extracellular fatty acid production by engineered Escherichia coli. Our results showed overexpressing ‘TesA and the deletion of fadL in E. coli BL21 (DE3) improved extracellular fatty acid production, while deletion of fadD didn’t strengthen the extracellular fatty acid production for an undetermined mechanism. Moreover, the cultivation process controls contributed greatly to extracellular fatty acid production with respect to titer, cell growth and productivity by adjusting the temperature, adding ampicillin and employing on-line extraction. Under optimal conditions, the E. coli strain (pACY-‘tesA-ΔfadL) produced 4.8 g L−1 extracellular fatty acid, with the specific productivity of 0.02 g h−1 g−1dry cell mass, and the yield of 4.4% on glucose, while the ratios of cell-associated fatty acid versus extracellular fatty acid were kept below 0.5 after 15 h of cultivation. The fatty acids included C12:1, C12:0, C14:1, C14:0, C16:1, C16:0, C18:1, C18:0. The composition was dominated by C14 and C16 saturated and unsaturated fatty acids. Using the strain pACY-‘tesA, similar results appeared under the same culture conditions and the titer was also much higher than that ever reported previously, which suggested that the supposedly superior strain did not necessarily perform best for the efficient production of desired product. The strain p

  9. Enzymatic Production of Extracellular Reactive Oxygen Species by Marine Microorganisms

    NASA Astrophysics Data System (ADS)

    Diaz, J. M.; Andeer, P. F.; Hansel, C. M.

    2014-12-01

    Reactive oxygen species (ROS) serve as intermediates in a myriad of biogeochemically important processes, including cell signaling pathways, cellular oxidative stress responses, and the transformation of both nutrient and toxic metals such as iron and mercury. Abiotic reactions involving the photo-oxidation of organic matter were once considered the only important sources of ROS in the environment. However, the recent discovery of substantial biological ROS production in marine systems has fundamentally shifted this paradigm. Within the last few decades, marine phytoplankton, including diatoms of the genus Thalassiosira, were discovered to produce ample extracellular quantities of the ROS superoxide. Even more recently, we discovered widespread production of extracellular superoxide by phylogenetically and ecologically diverse heterotrophic bacteria at environmentally significant levels (up to 20 amol cell-1 hr-1), which has introduced the revolutionary potential for substantial "dark" cycling of ROS. Despite the profound biogeochemical importance of extracellular biogenic ROS, the cellular mechanisms underlying the production of this ROS have remained elusive. Through the development of a gel-based assay to identify extracellular ROS-producing proteins, we have recently found that enzymes typically involved in antioxidant activity also produce superoxide when molecular oxygen is the only available electron acceptor. For example, large (~3600 amino acids) heme peroxidases are involved in extracellular superoxide production by a bacterium within the widespread Roseobacter clade. In Thalassiosira spp., extracellular superoxide is produced by flavoproteins such as glutathione reductase and ferredoxin NADP+ reductase. Thus, extracellular ROS production may occur via secreted and/or cell surface enzymes that modulate between producing and degrading ROS depending on prevailing geochemical and/or ecological conditions.

  10. Industrial-strength ecology: trade-offs and opportunities in algal biofuel production.

    PubMed

    Shurin, Jonathan B; Abbott, Rachel L; Deal, Michael S; Kwan, Garfield T; Litchman, Elena; McBride, Robert C; Mandal, Shovon; Smith, Val H

    2013-11-01

    Microalgae represent one of the most promising groups of candidate organisms for replacing fossil fuels with contemporary primary production as a renewable source of energy. Algae can produce many times more biomass per unit area than terrestrial crop plants, easing the competing demands for land with food crops and native ecosystems. However, several aspects of algal biology present unique challenges to the industrial-scale aquaculture of photosynthetic microorganisms. These include high susceptibility to invading aquatic consumers and weeds, as well as prodigious requirements for nutrients that may compete with the fertiliser demands of other crops. Most research on algal biofuel technologies approaches these problems from a cellular or genetic perspective, attempting either to engineer or select algal strains with particular traits. However, inherent functional trade-offs may limit the capacity of genetic selection or synthetic biology to simultaneously optimise multiple functional traits for biofuel productivity and resilience. We argue that a community engineering approach that manages microalgal diversity, species composition and environmental conditions may lead to more robust and productive biofuel ecosystems. We review evidence for trade-offs, challenges and opportunities in algal biofuel cultivation with a goal of guiding research towards intensifying bioenergy production using established principles of community and ecosystem ecology. PMID:24015819

  11. Complete Genome Sequence of Enterococcus faecalis Strain W11 Isolated from an Algal Food Product

    PubMed Central

    Takizawa, Noboru

    2016-01-01

    Here, we report the complete genome sequence of Enterococcus faecalis strain W11 isolated from an algal food product in Japan. This study should facilitate the identification of a novel mechanism of glycerol metabolic control in lactic acid bacteria. PMID:27688337

  12. Industrial-strength ecology: trade-offs and opportunities in algal biofuel production.

    PubMed

    Shurin, Jonathan B; Abbott, Rachel L; Deal, Michael S; Kwan, Garfield T; Litchman, Elena; McBride, Robert C; Mandal, Shovon; Smith, Val H

    2013-11-01

    Microalgae represent one of the most promising groups of candidate organisms for replacing fossil fuels with contemporary primary production as a renewable source of energy. Algae can produce many times more biomass per unit area than terrestrial crop plants, easing the competing demands for land with food crops and native ecosystems. However, several aspects of algal biology present unique challenges to the industrial-scale aquaculture of photosynthetic microorganisms. These include high susceptibility to invading aquatic consumers and weeds, as well as prodigious requirements for nutrients that may compete with the fertiliser demands of other crops. Most research on algal biofuel technologies approaches these problems from a cellular or genetic perspective, attempting either to engineer or select algal strains with particular traits. However, inherent functional trade-offs may limit the capacity of genetic selection or synthetic biology to simultaneously optimise multiple functional traits for biofuel productivity and resilience. We argue that a community engineering approach that manages microalgal diversity, species composition and environmental conditions may lead to more robust and productive biofuel ecosystems. We review evidence for trade-offs, challenges and opportunities in algal biofuel cultivation with a goal of guiding research towards intensifying bioenergy production using established principles of community and ecosystem ecology.

  13. Complete Genome Sequence of Enterococcus faecalis Strain W11 Isolated from an Algal Food Product.

    PubMed

    Doi, Yuki; Takizawa, Noboru

    2016-01-01

    Here, we report the complete genome sequence of Enterococcus faecalis strain W11 isolated from an algal food product in Japan. This study should facilitate the identification of a novel mechanism of glycerol metabolic control in lactic acid bacteria. PMID:27688337

  14. Algal biomass and primary production within a temperate zone sandstone

    SciTech Connect

    Bell, R.A.; Sommerfeld, M.R. )

    1987-02-01

    The use of dimethyl sulfoxide (DMSO) to extract chlorophyll a and {sup 14}C-labelled photosynthate from endolithic algae of sparsely vegetated, cold temperate grasslands on the Colorado Plateau in Arizona has yielded the first estimates of biomass and photosynthesis for this unusual community. These subsurface microorganisms are found widespread in exposed Coconino Sandstone, a predominant formation in this cold temperate region. The endolithic community in Coconino Sandstone, composed primarily of coccoid blue-green and coccoid/sarcinoid green algae, yielded a biomass value (as chlorophyll a content) of 87 mg m{sup {minus}2} rock surface area and a photosynthetic rate of 0.37 mg CO{sub 2} dm{sup {minus}2} hr{sup {minus}1} or 0.48 mg CO{sub 2} mg{sup {minus}1} chl a hr{sup {minus}1}. The endolithic algal community contributes moderate biomass (5-10%) and substantial photosynthesis (20-80%) to the sparse grassland ecosystem.

  15. Hydrogen production from algal biomass via steam gasification.

    PubMed

    Duman, Gozde; Uddin, Md Azhar; Yanik, Jale

    2014-08-01

    Algal biomasses were tested as feedstock for steam gasification in a dual-bed microreactor in a two-stage process. Gasification experiments were carried out in absence and presence of catalyst. The catalysts used were 10% Fe₂O₃-90% CeO₂ and red mud (activated and natural forms). Effects of catalysts on tar formation and gasification efficiencies were comparatively investigated. It was observed that the characteristic of algae gasification was dependent on its components and the catalysts used. The main role of the catalyst was reforming of the tar derived from algae pyrolysis, besides enhancing water gas shift reaction. The tar reduction levels were in the range of 80-100% for seaweeds and of 53-70% for microalgae. Fe₂O₃-CeO₂ was found to be the most effective catalyst. The maximum hydrogen yields obtained were 1036 cc/g algae for Fucus serratus, 937 cc/g algae for Laminaria digitata and 413 cc/g algae for Nannochloropsis oculata.

  16. Anomalous rise in algal production linked to lakewater calcium decline through food web interactions

    PubMed Central

    Korosi, Jennifer B.; Burke, Samantha M.; Thienpont, Joshua R.; Smol, John P.

    2012-01-01

    Increased algal blooms are a threat to aquatic ecosystems worldwide, although the combined effects of multiple stressors make it difficult to determine the underlying causes. We explore whether changes in trophic interactions in response to declining calcium (Ca) concentrations, a water quality issue only recently recognized in Europe and North America, can be linked with unexplained bloom production. Using a palaeolimnological approach analysing the remains of Cladocera (herbivorous grazers) and visual reflectance spectroscopically inferred chlorophyll a from the sediments of a Nova Scotia (Canada) lake, we show that a keystone grazer, Daphnia, declined in the early 1990s and was replaced by a less effective grazer, Bosmina, while inferred chlorophyll a levels tripled at constant total phosphorus (TP) concentrations. The decline in Daphnia cannot be attributed to changes in pH, thermal stratification or predation, but instead is linked to declining lakewater [Ca]. The consistency in the timing of changes in Daphnia and inferred chlorophyll a suggests top-down control on algal production, providing, to our knowledge, the first evidence of a link between lakewater [Ca] decline and elevated algal production mediated through the effects of [Ca] decline on Daphnia. [Ca] decline has severe implications for whole-lake food webs, and presents yet another mechanism for potential increases in algal blooms. PMID:21957138

  17. Process Design and Economics for the Conversion of Algal Biomass to Biofuels: Algal Biomass Fractionation to Lipid-and Carbohydrate-Derived Fuel Products

    SciTech Connect

    Davis, R.; Kinchin, C.; Markham, J.; Tan, E. C. D.; Laurens, L. M. L.; Sexton, D.; Knorr, D.; Schoen, P.; Lukas, J.

    2014-09-11

    The U.S. Department of Energy (DOE) promotes the production of a range of liquid fuels and fuel blendstocks from biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass production, conversion, and sustainability. As part of its involvement in this program, the National Renewable Energy Laboratory (NREL) investigates the conceptual production economics of these fuels. This includes fuel pathways from lignocellulosic (terrestrial) biomass, as well as from algal (aquatic) biomass systems.

  18. Biodiesel from wastewater: lipid production in high rate algal pond receiving disinfected effluent.

    PubMed

    Assemany, Paula Peixoto; Calijuri, Maria Lucia; do Couto, Eduardo de Aguiar; Santiago, Aníbal Fonseca; Dos Reis, Alberto José Delgado

    2015-01-01

    The production of different species of microalgae in consortium with other micro-organisms from wastewaters may represent an alternative process, to reduce the costs, for obtaining biofuels. The aim of this study was to evaluate the influence of pre-ultraviolet disinfection (UV) in the production of lipids from biomass produced in high rate ponds. Two high rate algal ponds were evaluated: a pond that received domestic sewage without disinfection and the other receiving domestic sewage previously disinfected by UV radiation (uvHRAP). The UV disinfection did not lead to significant differences in fatty acid profile and total lipid productivities, although it increased algal biomass concentration and productivity as well as lipid content. Moreover, the overall biomass concentrations and productivities decreased with the UV disinfection, mostly as a consequence of a loss in bacterial load. We thus conclude that uvHRAP disinfection may represent a potential strategy to promote the cleaner and safer growth of algal biomass when cultivated in consortium with other micro-organisms. Mainly regarding the use of wastewater as culture medium, together with a cheaper production of lipids for biodiesel, pre-disinfection may represent an advance since extraction costs could be significantly trimmed due to the increase in lipid content.

  19. The macrophage chemotactic activity of Edwardsiella tarda extracellular products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chemoattractant capabilities of Edwardsiella tarda extracellular products (ECP) were investigated from two isolates, the virulent FL6-60 parent and less virulent RET-04 mutant. Chemotaxis and chemokinesis were assayed in vitro using blind well chambers with peritoneal macrophages obtained from ...

  20. Production of algal-based biofuel using non-fresh water sources.

    SciTech Connect

    Sun, Amy Cha-Tien; Reno, Marissa Devan

    2007-09-01

    The goal of this LDRD involves development of a system dynamics model to understand the interdependencies between water resource availability and water needs for production of biofuels. Specifically, this model focuses on availability and feasibility of non-traditional water sources from dairy wastewater, produced water from crude oil production and from coal-bed methane gas extraction for the production of algal-based biofuel. The conceptual simulation framework and historical data are based on two locales within New Mexico, the San Juan basin in the northwest and the Permian basin in the southeast, where oil and gas drilling have increased considerably in the last ten years. The overall water balance ignores both transportation options and water chemistry and is broken down by county level. The resulting model contains an algal growth module, a dairy module, an oil production module, and a gas production module. A user interface is also created for controlling the adjustable parameters in the model. Our preliminary investigation indicates a cyclical demand for non-fresh water due to the cyclical nature of algal biomass production and crop evapotranspiration. The wastewater from the dairy industry is not a feasible non-fresh water source because the agricultural water demand for cow's dry feed far exceeds the amount generated at the dairy. The uncertainty associated with the water demand for cow's dry matter intake is the greatest in this model. The oil- and gas-produced water, ignoring the quality, provides ample supply for water demand in algal biomass production. There remains work to address technical challenges associated with coupling the appropriate non-fresh water source to the local demand.

  1. An Energy-limited Model of Algal Biofuels Production: Towards the Next Generation of Advanced Biofuels

    DOE PAGES

    Dunlop, Eric

    2013-01-01

    Algal biofuels are increasingly important as a source of renewable energy. The absence of reliable thermodynamic and other property data, and the large amount of kinetic data that would normally be required have created a major barrier to simulation. Additionally, the absence of a generally accepted flowsheet for biofuel production means that detailed simulation of the wrong approach is a real possibility. This model of algal biofuel production estimates the necessary data and places it into a heuristic model using a commercial simulator that back-calculates the process structure required. Furthermore, complex kinetics can be obviated for now by putting themore » simulator into energy limitation and forcing it to solve for the missing design variables, such as bioreactor surface area, productivity, and oil content. The model does not attempt to prescribe a particular approach, but provides a guide towards a sound engineering approach to this challenging and important problem.« less

  2. An energy-limited model of algal biofuel production: Toward the next generation of advanced biofuels

    DOE PAGES

    Dunlop, Eric H.; Coaldrake, A. Kimi; Silva, Cory S.; Seider, Warren D.

    2013-10-22

    Algal biofuels are increasingly important as a source of renewable energy. The absence of reliable thermodynamic and other property data, and the large amount of kinetic data that would normally be required have created a major barrier to simulation. Additionally, the absence of a generally accepted flowsheet for biofuel production means that detailed simulation of the wrong approach is a real possibility. This model of algal biofuel production estimates the necessary data and places it into a heuristic model using a commercial simulator that back-calculates the process structure required. Furthermore, complex kinetics can be obviated for now by putting themore » simulator into energy limitation and forcing it to solve for the missing design variables, such as bioreactor surface area, productivity, and oil content. The model does not attempt to prescribe a particular approach, but provides a guide towards a sound engineering approach to this challenging and important problem.« less

  3. An energy-limited model of algal biofuel production: Toward the next generation of advanced biofuels

    SciTech Connect

    Dunlop, Eric H.; Coaldrake, A. Kimi; Silva, Cory S.; Seider, Warren D.

    2013-10-22

    Algal biofuels are increasingly important as a source of renewable energy. The absence of reliable thermodynamic and other property data, and the large amount of kinetic data that would normally be required have created a major barrier to simulation. Additionally, the absence of a generally accepted flowsheet for biofuel production means that detailed simulation of the wrong approach is a real possibility. This model of algal biofuel production estimates the necessary data and places it into a heuristic model using a commercial simulator that back-calculates the process structure required. Furthermore, complex kinetics can be obviated for now by putting the simulator into energy limitation and forcing it to solve for the missing design variables, such as bioreactor surface area, productivity, and oil content. The model does not attempt to prescribe a particular approach, but provides a guide towards a sound engineering approach to this challenging and important problem.

  4. The place of algae in agriculture: policies for algal biomass production.

    PubMed

    Trentacoste, Emily M; Martinez, Alice M; Zenk, Tim

    2015-03-01

    Algae have been used for food and nutraceuticals for thousands of years, and the large-scale cultivation of algae, or algaculture, has existed for over half a century. More recently algae have been identified and developed as renewable fuel sources, and the cultivation of algal biomass for various products is transitioning to commercial-scale systems. It is crucial during this period that institutional frameworks (i.e., policies) support and promote development and commercialization and anticipate and stimulate the evolution of the algal biomass industry as a source of renewable fuels, high value protein and carbohydrates and low-cost drugs. Large-scale cultivation of algae merges the fundamental aspects of traditional agricultural farming and aquaculture. Despite this overlap, algaculture has not yet been afforded a position within agriculture or the benefits associated with it. Various federal and state agricultural support and assistance programs are currently appropriated for crops, but their extension to algal biomass is uncertain. These programs are essential for nascent industries to encourage investment, build infrastructure, disseminate technical experience and information, and create markets. This review describes the potential agricultural policies and programs that could support algal biomass cultivation, and the barriers to the expansion of these programs to algae.

  5. Transformation of Swine Manure and Algal Consortia to Value-added Products

    NASA Astrophysics Data System (ADS)

    Sharara, Mahmoud A.

    The swine production sector is projected to grow globally. In the past, this growth manifested itself in increased herd sizes and geographically concentrated production. Although economically sound, these trends had negative consequences on surrounding ecosystems. Over-application of manure resulted in water quality degradation, while long-term storage of manure slurries was found to promote release of potent GHG emissions. There is a need for innovative approaches for swine manure management that are compatible with current scales of production, and increasingly strict environmental regulations. This study aims to investigate the potential for incorporating gasification as part of a novel swine manure management system which utilizes liquid-solid separation and periphytic algal consortia as a phycoremediation vector for the liquid slurry. The gasification of swine manure solids, and algal biomass solids generate both a gaseous fuel product (producer gas) in addition to a biochar co-product. First, the decomposition kinetics for both feedstock, i.e., swine manure solids, and algal solids, were quantified using thermogravimetry at different heating rates (1 ~ 40°C min-1) under different atmospheres (nitrogen, and air). Pyrolysis kinetics were determined for manure solids from two farms with different manure management systems. Similarly, the pyrolysis kinetics were determined for phycoremediation algae grown on swine manure slurries. Modeling algal solids pyrolysis as first-order independent parallel reactions was sufficient to describe sample devolatilization. Combustion of swine manure solids blended with algal solids, at different ratios, showed no synergistic effects. Gasification of phycoremediation algal biomass was studied using a bench-scale auger gasification system at temperatures between 760 and 960°C. The temperature profile suggested a stratification of reaction zones common to fixed-bed reactors. The producer gas heating value ranged between 2.2 MJ m

  6. Effect of process variables on photosynthetic algal hydrogen production.

    PubMed

    Hahn, John J; Ghirardi, Maria L; Jacoby, William A

    2004-01-01

    Chlamydomonas reinhardtii is a green alga that can use the sun's energy to split water into O(2) and H(2). This is accomplished by means of a two-phase cycle, an aerobic growth phase followed by an anaerobic hydrogen production phase. The effects of process variables on hydrogen production are examined here. These variables include cell concentration, light intensity, and reactor design parameters that affect light transport and mixing. An optimum cell concentration and light intensity are identified, and two reactor designs are compared. The maximum hydrogen production observed in this study was 0.29 mL of hydrogen per milliliter of suspension. This was measured at atmospheric pressure during a 96 h production cycle. This corresponds to an average hydrogen production rate of 0.12 mmol/mL.h. PMID:15176910

  7. Relationships between primary production and irradiance in coral reef algal communities

    SciTech Connect

    Not Available

    1985-07-01

    Shallow water algal turf communities are the major primary producers on coral reefs. High rates of primary production are maintained despite extremely high light intensities and exposure to ultraviolet wavelengths. The relationships between the light intensity and primary production in these assemblages are typical of algae adapted to a high light environment (low ..cap alpha.. (initial slope), high I/sub k/ (saturating light intensity), and high I/sub c/ (compensation point light intensity)). Seasonal variations in algal standing crop due to herbivory and daylength result in some characteristic photoadaptive changes in ..cap alpha.. I/sub k/, and I/sub c/ and changes in Pnet/sub max/ rates (maximum net photosynthetic rate achieved at light saturation) on both a chlorophyll ..cap alpha.. and an areal basis. Exposure to UV wavelength results in significantly higher respiration rates but no changes in ..cap alpha.., Pnet/sub max/, or I/sub k/, when compared with these parameters for the same algal communities incubated at the same light intensities without UV wavelengths. The apparent lack of photoinhibition in these algae allows calculation of the daily integrated production from the P vs. I parameters. This integrated production is highest in July (3.1 +/- 0.2 g C m/sup -2/d/sup -1/) and is reduced by 30% from this maximum in December (2.1 +/- 0.1 g C m/sup -2/d/sup -1/).

  8. An analysis of the productivity of a CELSS continuous algal culture system

    NASA Technical Reports Server (NTRS)

    Radmer, R.; Behrens, P.; Fernandez, E.; Arnett, K.

    1986-01-01

    One of the most attractive aspects of using algal cultures as plant components for a Closed Ecological Life Support Systems (CELSS) is the efficiency with which they can be grown. Although algae are not necessarily intrinsically more efficient than higher plants, the ease which they can be handled and manipulated (more like chemical reagents than plants), and the culturing techniques available, result in much higher growth rates than are usually attainable with higher plants. Furthermore, preliminary experiments have demonstrated that algal growth and physiology is not detectable altered in a microgravity environment, (1) whereas the response of higher plants to zero gravity is unknown. In order to rationally design and operate culture systems, it is necessary to understand how the macroparameters of a culture system, e.g., productivity, are related to the physiological aspects of the algal culture. A first principles analysis of culture system is discussed, and a mathematical model that describes the relationship of culture productivity to the cell concentration of light-limited culture is derived. The predicted productivity vs cell concentration curve agrees well with the experimental data obtained to test this model, indicating that this model permits an accurate prediction of culture productivity given the growth parameters of the system.

  9. Hydraulic retention time effects on wastewater nutrient removal and bioproduct production via rotating algal biofilm reactor.

    PubMed

    Iman Shayan, Sahand; Agblevor, Foster A; Bertin, Lorenzo; Sims, Ronald C

    2016-07-01

    Rotating algal biofilm reactor (RABR) technology was successfully employed in an effective strategy to couple the removal of wastewater nutrients with accumulation of valuable bioproducts by grown algae. A secondary stage municipal wastewater was fed to the developed system and the effects of the hydraulic retention time (HRT) parameter on both nutrient removal and bioproduct production were evaluated under fed-batch operation mode. Two sets of bench scale RABRs were designed and operated with HRTs of 2 and 6days in order to provide competitive environment for algal growth. The HRT significantly affected nitrogen and phosphorus uptakes along with lipid and starch accumulations by microalgae in harvested biofilms. Domination of nitrogen removal in 2-day HRT with higher lipid accumulation (20% on dried weight basis) and phosphorus removal in 6-day HRT with higher starch production (27% on dried weight basis) was observed by comparing the performances of the RABRs in duplicate runs. PMID:27038261

  10. Experimental Protocol for Biodiesel Production with Isolation of Alkenones as Coproducts from Commercial Isochrysis Algal Biomass

    PubMed Central

    O'Neil, Gregory W.; Williams, John R.; Wilson-Peltier, Julia; Knothe, Gerhard; Reddy, Christopher M.

    2016-01-01

    The need to replace petroleum fuels with alternatives from renewable and more environmentally sustainable sources is of growing importance. Biomass-derived biofuels have gained considerable attention in this regard, however first generation biofuels from edible crops like corn ethanol or soybean biodiesel have generally fallen out of favor. There is thus great interest in the development of methods for the production of liquid fuels from domestic and superior non-edible sources. Here we describe a detailed procedure for the production of a purified biodiesel from the marine microalgae Isochrysis. Additionally, a unique suite of lipids known as polyunsaturated long-chain alkenones are isolated in parallel as potentially valuable coproducts to offset the cost of biodiesel production. Multi-kilogram quantities of Isochrysis are purchased from two commercial sources, one as a wet paste (80% water) that is first dried prior to processing, and the other a dry milled powder (95% dry). Lipids are extracted with hexanes in a Soxhlet apparatus to produce an algal oil ("hexane algal oil") containing both traditional fats (i.e., triglycerides, 46-60% w/w) and alkenones (16-25% w/w). Saponification of the triglycerides in the algal oil allows for separation of the resulting free fatty acids (FFAs) from alkenone-containing neutral lipids. FFAs are then converted to biodiesel (i.e., fatty acid methyl esters, FAMEs) by acid-catalyzed esterification while alkenones are isolated and purified from the neutral lipids by crystallization. We demonstrate that biodiesel from both commercial Isochrysis biomasses have similar but not identical FAME profiles, characterized by elevated polyunsaturated fatty acid contents (approximately 40% w/w). Yields of biodiesel were consistently higher when starting from the Isochrysis wet paste (12% w/w vs. 7% w/w), which can be traced to lower amounts of hexane algal oil obtained from the powdered Isochrysis product. PMID:27404113

  11. Experimental Protocol for Biodiesel Production with Isolation of Alkenones as Coproducts from Commercial Isochrysis Algal Biomass.

    PubMed

    O'Neil, Gregory W; Williams, John R; Wilson-Peltier, Julia; Knothe, Gerhard; Reddy, Christopher M

    2016-01-01

    The need to replace petroleum fuels with alternatives from renewable and more environmentally sustainable sources is of growing importance. Biomass-derived biofuels have gained considerable attention in this regard, however first generation biofuels from edible crops like corn ethanol or soybean biodiesel have generally fallen out of favor. There is thus great interest in the development of methods for the production of liquid fuels from domestic and superior non-edible sources. Here we describe a detailed procedure for the production of a purified biodiesel from the marine microalgae Isochrysis. Additionally, a unique suite of lipids known as polyunsaturated long-chain alkenones are isolated in parallel as potentially valuable coproducts to offset the cost of biodiesel production. Multi-kilogram quantities of Isochrysis are purchased from two commercial sources, one as a wet paste (80% water) that is first dried prior to processing, and the other a dry milled powder (95% dry). Lipids are extracted with hexanes in a Soxhlet apparatus to produce an algal oil ("hexane algal oil") containing both traditional fats (i.e., triglycerides, 46-60% w/w) and alkenones (16-25% w/w). Saponification of the triglycerides in the algal oil allows for separation of the resulting free fatty acids (FFAs) from alkenone-containing neutral lipids. FFAs are then converted to biodiesel (i.e., fatty acid methyl esters, FAMEs) by acid-catalyzed esterification while alkenones are isolated and purified from the neutral lipids by crystallization. We demonstrate that biodiesel from both commercial Isochrysis biomasses have similar but not identical FAME profiles, characterized by elevated polyunsaturated fatty acid contents (approximately 40% w/w). Yields of biodiesel were consistently higher when starting from the Isochrysis wet paste (12% w/w vs. 7% w/w), which can be traced to lower amounts of hexane algal oil obtained from the powdered Isochrysis product. PMID:27404113

  12. Experimental Protocol for Biodiesel Production with Isolation of Alkenones as Coproducts from Commercial Isochrysis Algal Biomass.

    PubMed

    O'Neil, Gregory W; Williams, John R; Wilson-Peltier, Julia; Knothe, Gerhard; Reddy, Christopher M

    2016-06-24

    The need to replace petroleum fuels with alternatives from renewable and more environmentally sustainable sources is of growing importance. Biomass-derived biofuels have gained considerable attention in this regard, however first generation biofuels from edible crops like corn ethanol or soybean biodiesel have generally fallen out of favor. There is thus great interest in the development of methods for the production of liquid fuels from domestic and superior non-edible sources. Here we describe a detailed procedure for the production of a purified biodiesel from the marine microalgae Isochrysis. Additionally, a unique suite of lipids known as polyunsaturated long-chain alkenones are isolated in parallel as potentially valuable coproducts to offset the cost of biodiesel production. Multi-kilogram quantities of Isochrysis are purchased from two commercial sources, one as a wet paste (80% water) that is first dried prior to processing, and the other a dry milled powder (95% dry). Lipids are extracted with hexanes in a Soxhlet apparatus to produce an algal oil ("hexane algal oil") containing both traditional fats (i.e., triglycerides, 46-60% w/w) and alkenones (16-25% w/w). Saponification of the triglycerides in the algal oil allows for separation of the resulting free fatty acids (FFAs) from alkenone-containing neutral lipids. FFAs are then converted to biodiesel (i.e., fatty acid methyl esters, FAMEs) by acid-catalyzed esterification while alkenones are isolated and purified from the neutral lipids by crystallization. We demonstrate that biodiesel from both commercial Isochrysis biomasses have similar but not identical FAME profiles, characterized by elevated polyunsaturated fatty acid contents (approximately 40% w/w). Yields of biodiesel were consistently higher when starting from the Isochrysis wet paste (12% w/w vs. 7% w/w), which can be traced to lower amounts of hexane algal oil obtained from the powdered Isochrysis product.

  13. Improved photobiological H2 production in engineered green algal cells.

    PubMed

    Kruse, Olaf; Rupprecht, Jens; Bader, Klaus-Peter; Thomas-Hall, Skye; Schenk, Peer Martin; Finazzi, Giovanni; Hankamer, Ben

    2005-10-01

    Oxygenic photosynthetic organisms use solar energy to split water (H2O) into protons (H+), electrons (e-), and oxygen. A select group of photosynthetic microorganisms, including the green alga Chlamydomonas reinhardtii, has evolved the additional ability to redirect the derived H+ and e- to drive hydrogen (H2) production via the chloroplast hydrogenases HydA1 and A2 (H2 ase). This process occurs under anaerobic conditions and provides a biological basis for solar-driven H2 production. However, its relatively poor yield is a major limitation for the economic viability of this process. To improve H2 production in Chlamydomonas, we have developed a new approach to increase H+ and e- supply to the hydrogenases. In a first step, mutants blocked in the state 1 transition were selected. These mutants are inhibited in cyclic e- transfer around photosystem I, eliminating possible competition for e- with H2ase. Selected strains were further screened for increased H2 production rates, leading to the isolation of Stm6. This strain has a modified respiratory metabolism, providing it with two additional important properties as follows: large starch reserves (i.e. enhanced substrate availability), and a low dissolved O2 concentration (40% of the wild type (WT)), resulting in reduced inhibition of H2ase activation. The H2 production rates of Stm6 were 5-13 times that of the control WT strain over a range of conditions (light intensity, culture time, +/- uncoupler). Typically, approximately 540 ml of H2 liter(-1) culture (up to 98% pure) were produced over a 10-14-day period at a maximal rate of 4 ml h(-1) (efficiency = approximately 5 times the WT). Stm6 therefore represents an important step toward the development of future solar-powered H2 production systems. PMID:16100118

  14. Cost structures and life cycle impacts of algal biomass and biofuel production

    NASA Astrophysics Data System (ADS)

    Christiansen, Katrina Lea

    2011-12-01

    Development and extraction of energy sources, energy production and energy use have huge economic, environmental and geopolitical impacts. Increasing energy demands in tandem with reductions in fossil fuel production has led to significant investments in research into alternative forms of energy. One that is promising but yet not commercially established is the production of biofuel from algae. This research quantitatively assessed the potential of algae biofuel production by examining its cost and environmental impacts. First, two models developed by the RAND corporation were employed to assess Cost Growth defined as the ratio of actual costs to estimated costs, and Plant Performance defined as the ratio of actual production levels to design performance, of three algal biofuel production technologies. The three algal biofuel production technologies examined to open raceway ponds (ORPs), photobioreactors (PBRs), and a system that couples PBRs to ORPs (PBR-ORPs). Though these analyses lack precision due to uncertainty, the results highlight the risks associated with implementing algal biofuel systems, as all scenarios examined were predicted to have Cost Growth, ranging from 1.2 to 1.8, and Plant Performance was projected as less than 50% of design performance for all cases. Second, the Framework the Evaluation of Biomass Energy Feedstocks (FEBEF) was used to assess the cost and environmental impacts of biodiesel produced from three algal production technologies. When these results were compared with ethanol from corn and biodiesel from soybeans, biodiesel from algae produced from the different technologies were estimated to be more expensive, suffered from low energy gains, and did not result in lower greenhouse gas emissions. To identify likely routes to making algal biofuels more competitive, a third study was undertaken. In this case, FEBEF was employed to examine pinch-points (defined as the most costly, energy consuming, greenhouse gas producing processes), in

  15. Acid-Catalyzed Algal Biomass Pretreatment for Integrated Lipid and Carbohydrate-Based Biofuels Production

    SciTech Connect

    Laurens, L. M. L.; Nagle, N.; Davis, R.; Sweeney, N.; Van Wychen, S.; Lowell, A.; Pienkos, P. T.

    2014-11-12

    One of the major challenges associated with algal biofuels production in a biorefinery-type setting is improving biomass utilization in its entirety, increasing the process energetic yields and providing economically viable and scalable co-product concepts. We demonstrate the effectiveness of a novel, integrated technology based on moderate temperatures and low pH to convert the carbohydrates in wet algal biomass to soluble sugars for fermentation, while making lipids more accessible for downstream extraction and leaving a protein-enriched fraction behind. We studied the effect of harvest timing on the conversion yields, using two algal strains; Chlorella and Scenedesmus, generating biomass with distinctive compositional ratios of protein, carbohydrate, and lipids. We found that the late harvest Scenedesmus biomass had the maximum theoretical biofuel potential at 143 gasoline gallon equivalent (GGE) combined fuel yield per dry ton biomass, followed by late harvest Chlorella at 128 GGE per ton. Our experimental data show a clear difference between the two strains, as Scenedesmus was more successfully converted in this process with a demonstrated 97 GGE per ton. Our measurements indicated a release of >90% of the available glucose in the hydrolysate liquors and an extraction and recovery of up to 97% of the fatty acids from wet biomass. Techno-economic analysis for the combined product yields indicates that this process exhibits the potential to improve per-gallon fuel costs by up to 33% compared to a lipids-only process for one strain, Scenedesmus, grown to the mid-point harvest condition.

  16. Treatment of dairy manure effluent using freshwater algae: algal productivity and recovery of manure nutrients using pilot-scale algal turf scrubbers.

    PubMed

    Mulbry, Walter; Kondrad, Shannon; Pizarro, Carolina; Kebede-Westhead, Elizabeth

    2008-11-01

    Cultivating algae on nitrogen (N) and phosphorus (P) in animal manure effluents presents an alternative to the current practice of land application. The objective of this study was to determine values for productivity, nutrient content, and nutrient recovery using filamentous green algae grown in outdoor raceways at different loading rates of raw and anaerobically digested dairy manure effluent. Algal turf scrubber raceways (30m2 each) were operated in central Maryland for approximately 270 days each year (roughly April 1-December 31) from 2003 to 2006. Algal biomass was harvested every 4-12 days from the raceways after daily additions of manure effluent corresponding to loading rates of 0.3 to 2.5g total N (TN) and 0.08 to 0.42g total P (TP) m(-2)d(-1). Mean algal productivity values increased from approximately 2.5g DW m(-2)d(-1) at the lowest loading rate (0.3g TN m(-2)d(-1)) to 25g DW m(-2)d(-1) at the highest loading rate (2.5g TN m(-2)d(-1)). Mean N and P contents in the dried biomass increased 1.5-2.0-fold with increasing loading rate up to maximums of 7% N and 1% P (dry weight basis). Although variable, algal N and P accounted for roughly 70-90% of input N and P at loading rates below 1g TN, 0.15g TP m(-2)d(-1). N and P recovery rates decreased to 50-80% at higher loading rates. There were no significant differences in algal productivity, algal N and P content, or N and P recovery values from raceways with carbon dioxide supplementation compared to values from raceways without added carbon dioxide. Projected annual operational costs are very high on a per animal basis ($780 per cow). However, within the context of reducing nutrient inputs in sensitive watersheds such as the Chesapeake Bay, projected operational costs of $11 per kgN are well below the costs cited for upgrading existing water treatment plants. PMID:18487042

  17. Nutrient removal and biofuel production in high rate algal pond using real municipal wastewater.

    PubMed

    Kim, Byung-Hyuk; Kang, Zion; Ramanan, Rishiram; Choi, Jong-Eun; Cho, Dae-Hyun; Oh, Hee-Mock; Kim, Hee-Sik

    2014-08-01

    This study evaluated the growth and nutrient removal ability of an indigenous algal consortium on real untreated municipal wastewater in a high rate algal pond (HRAP). The HRAP was operated semicontinuously under different hydraulic retention times (HRT: 2, 4, 6, and 8 days). The average removal efficiencies of chemical oxygen demand, and total nitrogen and phosphate of real municipal wastewater were maintained at 85.44 ± 5.10%, 92.74 ± 5.82%, and 82.85 ± 8.63%, respectively, in 2 day HRT. Algae dominated the consortium and showed high settling efficiency (99%), and biomass and lipid productivity of 0.500 ± 0.03 g/l/day and 0.103 ± 0.0083 g/l/day (2 day HRT), respectively. Fatty acid methyl ester analysis revealed a predominance of palmitate (C16:0), palmitoleate (C16:1), linoleate (C18:2), and linolenate (C18:3). Microalgal diversity analyses determined the presence of Chlorella, Scenedesmus, and Stigeoclonium as the dominant microalgae. The algal consortium provides significant value not only in terms of energy savings and nutrient removal but also because of its bioenergy potential as indicated by the lipid content (20-23%) and FAME profiling. PMID:24759425

  18. Nutrient removal and biofuel production in high rate algal pond using real municipal wastewater.

    PubMed

    Kim, Byung-Hyuk; Kang, Zion; Ramanan, Rishiram; Choi, Jong-Eun; Cho, Dae-Hyun; Oh, Hee-Mock; Kim, Hee-Sik

    2014-08-01

    This study evaluated the growth and nutrient removal ability of an indigenous algal consortium on real untreated municipal wastewater in a high rate algal pond (HRAP). The HRAP was operated semicontinuously under different hydraulic retention times (HRT: 2, 4, 6, and 8 days). The average removal efficiencies of chemical oxygen demand, and total nitrogen and phosphate of real municipal wastewater were maintained at 85.44 ± 5.10%, 92.74 ± 5.82%, and 82.85 ± 8.63%, respectively, in 2 day HRT. Algae dominated the consortium and showed high settling efficiency (99%), and biomass and lipid productivity of 0.500 ± 0.03 g/l/day and 0.103 ± 0.0083 g/l/day (2 day HRT), respectively. Fatty acid methyl ester analysis revealed a predominance of palmitate (C16:0), palmitoleate (C16:1), linoleate (C18:2), and linolenate (C18:3). Microalgal diversity analyses determined the presence of Chlorella, Scenedesmus, and Stigeoclonium as the dominant microalgae. The algal consortium provides significant value not only in terms of energy savings and nutrient removal but also because of its bioenergy potential as indicated by the lipid content (20-23%) and FAME profiling.

  19. PRODUCTION OF EXTRACELLULAR GUANOSINE-5'-MONOPHOSPHATE BY BACILLUS SUBTILIS

    PubMed Central

    Demain, A. L.; Miller, I. M.; Hendlin, D.

    1964-01-01

    Demain, A. L. (Merck Sharp & Dohme Research Laboratories, Rahway, N.J.), I. M. Miller, and D. Hendlin. Production of extracellular guanosine-5'-monophosphate by Bacillus subtilis. J. Bacteriol. 88:991–995. 1964.—Wild-type Bacillus subtilis colonies were found to feed purineless mutants. A strain with high feeding capacity was selected for study, with a guanineless mutant of B. subtilis used as the assay organism. The factor was excreted during its growth phase in a complex medium containing starch and soybean meal extract. Nutritional studies led to the development of a defined medium to be used for biochemical studies and to aid in the isolation of the factor. Starch was replaced by maltose and the soybean meal extract by Mn++. Production of the factor was sensitive to the pH of the medium during growth. Practically its entire extracellular accumulation occurred before visible lysis. The factor was identified as guanosine-5'-monophosphate derived by extracellular enzymatic hydrolysis of excreted ribonucleic acid. PMID:14219064

  20. Process energy comparison for the production and harvesting of algal biomass as a biofuel feedstock.

    PubMed

    Weschler, Matthew K; Barr, William J; Harper, Willie F; Landis, Amy E

    2014-02-01

    Harvesting and drying are often described as the most energy intensive stages of microalgal biofuel production. This study analyzes two cultivation and eleven harvest technologies for the production of microalgae biomass with and without the use of drying. These technologies were combined to form 122 different production scenarios. The results of this study present a calculation methodology and optimization of total energy demand for the production of algal biomass for biofuel production. The energetic interaction between unit processes and total process energy demand are compared for each scenario. Energy requirements are shown to be highly dependent on final mass concentration, with thermal drying being the largest energy consumer. Scenarios that omit thermal drying in favor of lipid extraction from wet biomass show the most promise for energy efficient biofuel production. Scenarios which used open ponds for cultivation, followed by settling and membrane filtration were the most energy efficient.

  1. Red to red - the marine bacterium Hahella chejuensis and its product prodigiosin for mitigation of harmful algal blooms.

    PubMed

    Kim, Dockyu; Kim, Jihyun F; Yim, Joung Han; Kwon, Soon-Kyeong; Lee, Choong Hwan; Lee, Hong Kum

    2008-10-01

    Harmful algal blooms (HABs), commonly called red tides, are caused by some toxic phytoplanktons, and have made massive economic losses as well as marine environmental disturbances. As an effective and environment-friendly strategy to control HAB outbreaks, biological methods using marine bacteria capable of killing the harmful algae or algicidal extracellular compounds from them have been given attention. A new member of the gamma-Proteobacteria, Hahella chejuensis KCTC 2396, was originally isolated from the Korean seashore for its ability to secrete industrially useful polysaccharides, and was characterized to produce a red pigment. This pigment later was identified as an alkaloid compound, prodigiosin. During the past several decades, prodigiosin has been extensively studied for its medical potential as immunosuppressants and antitumor agents, owing to its antibiotic and cytotoxic activities. The lytic activity of this marvelous molecule against Cochlodinium polykrikoides cells at very low concentrations (1 ppb) was serendipitously detected, making H. chejuensis a strong candidate among the biological agents for HAB control. This review provides a brief overview of algicidal marine bacteria and their products, and describes in detail the algicidal characteristics, biosynthetic process, and genetic regulation of prodigiosin as a model among the compounds active against red-tide organisms from the biochemical and genetic viewpoints. PMID:18955809

  2. Red to red - the marine bacterium Hahella chejuensis and its product prodigiosin for mitigation of harmful algal blooms.

    PubMed

    Kim, Dockyu; Kim, Jihyun F; Yim, Joung Han; Kwon, Soon-Kyeong; Lee, Choong Hwan; Lee, Hong Kum

    2008-10-01

    Harmful algal blooms (HABs), commonly called red tides, are caused by some toxic phytoplanktons, and have made massive economic losses as well as marine environmental disturbances. As an effective and environment-friendly strategy to control HAB outbreaks, biological methods using marine bacteria capable of killing the harmful algae or algicidal extracellular compounds from them have been given attention. A new member of the gamma-Proteobacteria, Hahella chejuensis KCTC 2396, was originally isolated from the Korean seashore for its ability to secrete industrially useful polysaccharides, and was characterized to produce a red pigment. This pigment later was identified as an alkaloid compound, prodigiosin. During the past several decades, prodigiosin has been extensively studied for its medical potential as immunosuppressants and antitumor agents, owing to its antibiotic and cytotoxic activities. The lytic activity of this marvelous molecule against Cochlodinium polykrikoides cells at very low concentrations (1 ppb) was serendipitously detected, making H. chejuensis a strong candidate among the biological agents for HAB control. This review provides a brief overview of algicidal marine bacteria and their products, and describes in detail the algicidal characteristics, biosynthetic process, and genetic regulation of prodigiosin as a model among the compounds active against red-tide organisms from the biochemical and genetic viewpoints.

  3. Acid-Catalyzed Algal Biomass Pretreatment for Integrated Lipid and Carbohydrate-Based Biofuels Production

    DOE PAGES

    Laurens, L. M. L.; Nagle, N.; Davis, R.; Sweeney, N.; Van Wychen, S.; Lowell, A.; Pienkos, P. T.

    2014-11-12

    One of the major challenges associated with algal biofuels production in a biorefinery-type setting is improving biomass utilization in its entirety, increasing the process energetic yields and providing economically viable and scalable co-product concepts. We demonstrate the effectiveness of a novel, integrated technology based on moderate temperatures and low pH to convert the carbohydrates in wet algal biomass to soluble sugars for fermentation, while making lipids more accessible for downstream extraction and leaving a protein-enriched fraction behind. We studied the effect of harvest timing on the conversion yields, using two algal strains; Chlorella and Scenedesmus, generating biomass with distinctive compositionalmore » ratios of protein, carbohydrate, and lipids. We found that the late harvest Scenedesmus biomass had the maximum theoretical biofuel potential at 143 gasoline gallon equivalent (GGE) combined fuel yield per dry ton biomass, followed by late harvest Chlorella at 128 GGE per ton. Our experimental data show a clear difference between the two strains, as Scenedesmus was more successfully converted in this process with a demonstrated 97 GGE per ton. Our measurements indicated a release of >90% of the available glucose in the hydrolysate liquors and an extraction and recovery of up to 97% of the fatty acids from wet biomass. Techno-economic analysis for the combined product yields indicates that this process exhibits the potential to improve per-gallon fuel costs by up to 33% compared to a lipids-only process for one strain, Scenedesmus, grown to the mid-point harvest condition.« less

  4. Combinatorial life cycle assessment to inform process design of industrial production of algal biodiesel.

    PubMed

    Brentner, Laura B; Eckelman, Matthew J; Zimmerman, Julie B

    2011-08-15

    The use of algae as a feedstock for biodiesel production is a rapidly growing industry, in the United States and globally. A life cycle assessment (LCA) is presented that compares various methods, either proposed or under development, for algal biodiesel to inform the most promising pathways for sustainable full-scale production. For this analysis, the system is divided into five distinct process steps: (1) microalgae cultivation, (2) harvesting and/or dewatering, (3) lipid extraction, (4) conversion (transesterification) into biodiesel, and (5) byproduct management. A number of technology options are considered for each process step and various technology combinations are assessed for their life cycle environmental impacts. The optimal option for each process step is selected yielding a best case scenario, comprised of a flat panel enclosed photobioreactor and direct transesterification of algal cells with supercritical methanol. For a functional unit of 10 GJ biodiesel, the best case production system yields a cumulative energy demand savings of more than 65 GJ, reduces water consumption by 585 m(3) and decreases greenhouse gas emissions by 86% compared to a base case scenario typical of early industrial practices, highlighting the importance of technological innovation in algae processing and providing guidance on promising production pathways. PMID:21662987

  5. Combinatorial life cycle assessment to inform process design of industrial production of algal biodiesel.

    PubMed

    Brentner, Laura B; Eckelman, Matthew J; Zimmerman, Julie B

    2011-08-15

    The use of algae as a feedstock for biodiesel production is a rapidly growing industry, in the United States and globally. A life cycle assessment (LCA) is presented that compares various methods, either proposed or under development, for algal biodiesel to inform the most promising pathways for sustainable full-scale production. For this analysis, the system is divided into five distinct process steps: (1) microalgae cultivation, (2) harvesting and/or dewatering, (3) lipid extraction, (4) conversion (transesterification) into biodiesel, and (5) byproduct management. A number of technology options are considered for each process step and various technology combinations are assessed for their life cycle environmental impacts. The optimal option for each process step is selected yielding a best case scenario, comprised of a flat panel enclosed photobioreactor and direct transesterification of algal cells with supercritical methanol. For a functional unit of 10 GJ biodiesel, the best case production system yields a cumulative energy demand savings of more than 65 GJ, reduces water consumption by 585 m(3) and decreases greenhouse gas emissions by 86% compared to a base case scenario typical of early industrial practices, highlighting the importance of technological innovation in algae processing and providing guidance on promising production pathways.

  6. Algal productivity and nitrate assimilation in an effluent dominated concrete lined stream

    USGS Publications Warehouse

    Kent, R.; Belitz, K.; Burton, C.A.

    2005-01-01

    This study examined algal productivity and nitrate assimilation in a 2.85 km reach of Cucamonga Creek, California, a concrete lined channel receiving treated municipal wastewater. Stream nitrate concentrations observed at two stations indicated nearly continuous loss throughout the diel study. Nitrate loss in the reach was approximately 11 mg/L/d or 1.0 g/m2/d as N, most of which occurred during daylight. The peak rate of nitrate loss (1.13 mg/l/hr) occurred just prior to an afternoon total CO2 depletion. Gross primary productivity, as estimated by a model using the observed differences in dissolved oxygen between the two stations, was 228 mg/L/d, or 21 g/m2/d as O2. The observed diel variations in productivity, nitrate loss, pH, dissolved oxygen, and CO2 indicate that nitrate loss was primarily due to algal assimilation. The observed levels of productivity and nitrate assimilation were exceptionally high on a mass per volume basis compared to studies on other streams; these rates occurred because of the shallow stream depth. This study suggests that concrete-lined channels can provide an important environmental service: lowering of nitrate concentrations similar to rates observed in biological treatment systems.

  7. Energy return on investment for algal biofuel production coupled with wastewater treatment.

    PubMed

    Beal, Colin M; Stillwell, Ashlynn S; King, Carey W; Cohen, Stuart M; Berberoglu, Halil; Bhattarai, Rajendra P; Connelly, Rhykka L; Webber, Michael E; Hebner, Robert E

    2012-09-01

    This study presents a second-order energy return on investment analysis to evaluate the mutual benefits of combining an advanced wastewater treatment plant (WWTP) (with biological nutrient removal) with algal biofuel production. With conventional, independently operated systems, algae production requires significant material inputs, which require energy directly and indirectly, and the WWTP requires significant energy inputs for treatment of the waste streams. The second-order energy return on investment values for independent operation of the WWTP and the algal biofuels production facility were determined to be 0.37 and 0.42, respectively. By combining the two, energy inputs can be reduced significantly. Consequently, the integrated system can outperform the isolated system, yielding a second-order energy return on investment of 1.44. Combining these systems transforms two energy sinks to a collective (second-order) energy source. However, these results do not include capital, labor, and other required expenses, suggesting that profitable deployment will be challenging. PMID:23012769

  8. AlgaeSim: a model for integrated algal biofuel production and wastewater treatment.

    PubMed

    Drexler, Ivy L C; Joustra, Caryssa; Prieto, Ana; Bair, Robert; Yeh, Daniel H

    2014-02-01

    AlgaeSim, a dynamic multiple-systems (C, N, P) mass balance model, was developed to explore the potential for algae biomass production from wastewater by coupling two photobioreactors into the main treatment train at a municipal wastewater resource recovery facility (WRRF) in Tampa, Florida. The scoping model examined the synergy between algae cultivation and wastewater treatment through algal growth and substrate removal kinetics, as well as through macroeconomic analyses of biomass conversion to bioproducts. Sensitivity analyses showed that biomass production is strongly dependent on Monod variables and harvesting regime, with sensitivity changing with growth phase. Profitability was sensitive to processing costs and market prices of products. Under scenarios based on current market conditions and typical algae production, AlgaeSim shows that a WRRF can potentially generate significant profit if algae are processed for biodiesel, biogas, or fertilizer. Wastewater resource recovery facilities could similarly save on operating costs resulting from the reduction in aeration (for nitrification) and chemicals (for denitrification).

  9. Comprehensive techno-economic analysis of wastewater-based algal biofuel production: A case study.

    PubMed

    Xin, Chunhua; Addy, Min M; Zhao, Jinyu; Cheng, Yanling; Cheng, Sibo; Mu, Dongyan; Liu, Yuhuan; Ding, Rijia; Chen, Paul; Ruan, Roger

    2016-07-01

    Combining algae cultivation and wastewater treatment for biofuel production is considered the feasible way for resource utilization. An updated comprehensive techno-economic analysis method that integrates resources availability into techno-economic analysis was employed to evaluate the wastewater-based algal biofuel production with the consideration of wastewater treatment improvement, greenhouse gases emissions, biofuel production costs, and coproduct utilization. An innovative approach consisting of microalgae cultivation on centrate wastewater, microalgae harvest through flocculation, solar drying of biomass, pyrolysis of biomass to bio-oil, and utilization of co-products, was analyzed and shown to yield profound positive results in comparison with others. The estimated break even selling price of biofuel ($2.23/gallon) is very close to the acceptable level. The approach would have better overall benefits and the internal rate of return would increase up to 18.7% if three critical components, namely cultivation, harvest, and downstream conversion could achieve breakthroughs.

  10. Comprehensive techno-economic analysis of wastewater-based algal biofuel production: A case study.

    PubMed

    Xin, Chunhua; Addy, Min M; Zhao, Jinyu; Cheng, Yanling; Cheng, Sibo; Mu, Dongyan; Liu, Yuhuan; Ding, Rijia; Chen, Paul; Ruan, Roger

    2016-07-01

    Combining algae cultivation and wastewater treatment for biofuel production is considered the feasible way for resource utilization. An updated comprehensive techno-economic analysis method that integrates resources availability into techno-economic analysis was employed to evaluate the wastewater-based algal biofuel production with the consideration of wastewater treatment improvement, greenhouse gases emissions, biofuel production costs, and coproduct utilization. An innovative approach consisting of microalgae cultivation on centrate wastewater, microalgae harvest through flocculation, solar drying of biomass, pyrolysis of biomass to bio-oil, and utilization of co-products, was analyzed and shown to yield profound positive results in comparison with others. The estimated break even selling price of biofuel ($2.23/gallon) is very close to the acceptable level. The approach would have better overall benefits and the internal rate of return would increase up to 18.7% if three critical components, namely cultivation, harvest, and downstream conversion could achieve breakthroughs. PMID:27039331

  11. Development of an efficient algal H{sub 2}-production system

    SciTech Connect

    Ghirardi, M.L.; Flynn, T.; Forestier, M.; Seibert, M.

    1998-08-01

    Two major problems facing the development of a commercial photobiological algal H{sub 2}-producing system are the low rates of H{sub 2} evolution and the sensitivity of the H{sub 2}-evolving enzyme system to O{sub 2}, a by-product of the photosynthetic water-splitting process. The objective of this project is to generate O{sub 2}-tolerant mutants from the green alga Chlamydomonas reinhardtii that are high producers of H{sub 2} for use in a photobiological water-splitting, H{sub 2}-producing system that is cost effective, renewable, scalable, and non-polluting. The authors are currently employing a dual approach to address the O{sub 2}-sensitivity problem. The first approach, based on classical mutagenesis and selection procedures, depends on the ability of a mutagenized population of algal cells to survive under conditions that require them to either produce (H{sub 2}-production selection) or consume (photoreductive selection) H{sub 2} in the presence of controlled amounts of O{sub 2}. The second approach, based on molecular genetic strategies, involves the cloning of the hydrogenase gene from C. reinhardtii and identification of expression factors required for optimal H{sub 2}-evolution activity. The latter approach will complement the first in the future goal of generating a commercial organism suitable for use in the private sector.

  12. Marine algal natural products with anti-oxidative, anti-inflammatory, and anti-cancer properties

    PubMed Central

    2013-01-01

    For their various bioactivities, biomaterials derived from marine algae are important ingredients in many products, such as cosmetics and drugs for treating cancer and other diseases. This mini-review comprehensively compares the bioactivities and biological functions of biomaterials from red, green, brown, and blue-green algae. The anti-oxidative effects and bioactivities of several different crude extracts of algae have been evaluated both in vitro and in vivo. Natural products derived from marine algae protect cells by modulating the effects of oxidative stress. Because oxidative stress plays important roles in inflammatory reactions and in carcinogenesis, marine algal natural products have potential for use in anti-cancer and anti-inflammatory drugs. PMID:23724847

  13. Optimization of extracellular fungal peroxidase production by 2 Coprinus species.

    PubMed

    Ikehata, Keisuke; Pickard, Michael A; Buchanan, Ian D; Smith, Daniel W

    2004-12-01

    Optimum culture conditions for the batch production of extracellular peroxidase by Coprinus cinereus UAMH 4103 and Coprinus sp. UAMH 10067 were explored using 2 statistical experimental designs, including 2-level, 7-factor fractional factorial design and 2-factor central composite design. Of the 7 factors examined in the screening study, the concentrations of carbon (glucose) and nitrogen (peptone or casitone) sources showed significant effects on the peroxidase production by Coprinus sp. UAMH 10067. The optimum glucose and peptone concentrations were determined as 2.7% and 0.8% for Coprinus sp. UAMH 10067, and 2.9% and 1.4% for C. cinereus UAMH 4103, respectively. Under the optimized culture condition the maximum peroxidase activity achieved in this study was 34.5 U x mL(-1) for Coprinus sp. UAMH 10067 and 68.0 U x mL(-1) for C. cinereus UAMH 4103, more than 2-fold higher than the results of previous studies.

  14. Life cycle assessment of biodiesel production from algal bio-crude oils extracted under subcritical water conditions.

    PubMed

    Ponnusamy, Sundaravadivelnathan; Reddy, Harvind Kumar; Muppaneni, Tapaswy; Downes, Cara Meghan; Deng, Shuguang

    2014-10-01

    A life cycle assessment study is performed for the energy requirements and greenhouse gas emissions in an algal biodiesel production system. Subcritical water (SCW) extraction was applied for extracting bio-crude oil from algae, and conventional transesterification method was used for converting the algal oil to biodiesel. 58MJ of energy is required to produce 1kg of biodiesel without any co-products management, of which 36% was spent on cultivation and 56% on lipid extraction. SCW extraction with thermal energy recovery reduces the energy consumption by 3-5 folds when compared to the traditional solvent extraction. It is estimated that 1kg of algal biodiesel fixes about 0.6kg of CO2. An optimized case considering the energy credits from co-products could further reduce the total energy demand. The energy demand for producing 1kg of biodiesel in the optimized case is 28.23MJ.

  15. A strategy for urban outdoor production of high-concentration algal biomass for green biorefining.

    PubMed

    Lim, Chun Yong; Chen, Chia-Lung; Wang, Jing-Yuan

    2013-05-01

    The present study was to investigate the feasibility of carrying out effective microalgae cultivation and high-rate tertiary wastewater treatment simultaneously in a vertical sequencing batch photobioreactor with small areal footprint, suitable for sustainable urban microalgae production. For 15 consecutive days, Chlorella sorokiniana was cultivated in synthetic wastewater under various trophic conditions. A cycle of 12-h heterotrophic: 12-h mixotrophic condition produced 0.98 g l(-1) d(-1) of algal biomass in tandem with a 94.7% removal of 254.4 mg l(-1) C-acetate, a 100% removal of 84.7 mg l(-1) N-NH4 and a removal of 15.0 mg l(-1) P-PO4. The cells were harvested via cost-effective chitosan flocculation with multiple dosing (3 times) applying established chitosan:cell ratio (1:300 w/w) and pH control (6.3-6.8). Reproducible flocculation efficiencies of greater than 99% and high-concentration algal broths (>20% solids) were achieved. PMID:23186659

  16. Fish Sound Production in the Presence of Harmful Algal Blooms in the Eastern Gulf of Mexico

    PubMed Central

    Wall, Carrie C.; Lembke, Chad; Hu, Chuanmin; Mann, David A.

    2014-01-01

    This paper presents the first known research to examine sound production by fishes during harmful algal blooms (HABs). Most fish sound production is species-specific and repetitive, enabling passive acoustic monitoring to identify the distribution and behavior of soniferous species. Autonomous gliders that collect passive acoustic data and environmental data concurrently can be used to establish the oceanographic conditions surrounding sound-producing organisms. Three passive acoustic glider missions were conducted off west-central Florida in October 2011, and September and October 2012. The deployment period for two missions was dictated by the presence of red tide events with the glider path specifically set to encounter toxic Karenia brevis blooms (a.k.a red tides). Oceanographic conditions measured by the glider were significantly correlated to the variation in sounds from six known or suspected species of fish across the three missions with depth consistently being the most significant factor. At the time and space scales of this study, there was no detectable effect of red tide on sound production. Sounds were still recorded within red tide-affected waters from species with overlapping depth ranges. These results suggest that the fishes studied here did not alter their sound production nor migrate out of red tide-affected areas. Although these results are preliminary because of the limited measurements, the data and methods presented here provide a proof of principle and could serve as protocol for future studies on the effects of algal blooms on the behavior of soniferous fishes. To fully capture the effects of episodic events, we suggest that stationary or vertically profiling acoustic recorders and environmental sampling be used as a complement to glider measurements. PMID:25551564

  17. Fish sound production in the presence of harmful algal blooms in the eastern Gulf of Mexico.

    PubMed

    Wall, Carrie C; Lembke, Chad; Hu, Chuanmin; Mann, David A

    2014-01-01

    This paper presents the first known research to examine sound production by fishes during harmful algal blooms (HABs). Most fish sound production is species-specific and repetitive, enabling passive acoustic monitoring to identify the distribution and behavior of soniferous species. Autonomous gliders that collect passive acoustic data and environmental data concurrently can be used to establish the oceanographic conditions surrounding sound-producing organisms. Three passive acoustic glider missions were conducted off west-central Florida in October 2011, and September and October 2012. The deployment period for two missions was dictated by the presence of red tide events with the glider path specifically set to encounter toxic Karenia brevis blooms (a.k.a red tides). Oceanographic conditions measured by the glider were significantly correlated to the variation in sounds from six known or suspected species of fish across the three missions with depth consistently being the most significant factor. At the time and space scales of this study, there was no detectable effect of red tide on sound production. Sounds were still recorded within red tide-affected waters from species with overlapping depth ranges. These results suggest that the fishes studied here did not alter their sound production nor migrate out of red tide-affected areas. Although these results are preliminary because of the limited measurements, the data and methods presented here provide a proof of principle and could serve as protocol for future studies on the effects of algal blooms on the behavior of soniferous fishes. To fully capture the effects of episodic events, we suggest that stationary or vertically profiling acoustic recorders and environmental sampling be used as a complement to glider measurements.

  18. Fish sound production in the presence of harmful algal blooms in the eastern Gulf of Mexico.

    PubMed

    Wall, Carrie C; Lembke, Chad; Hu, Chuanmin; Mann, David A

    2014-01-01

    This paper presents the first known research to examine sound production by fishes during harmful algal blooms (HABs). Most fish sound production is species-specific and repetitive, enabling passive acoustic monitoring to identify the distribution and behavior of soniferous species. Autonomous gliders that collect passive acoustic data and environmental data concurrently can be used to establish the oceanographic conditions surrounding sound-producing organisms. Three passive acoustic glider missions were conducted off west-central Florida in October 2011, and September and October 2012. The deployment period for two missions was dictated by the presence of red tide events with the glider path specifically set to encounter toxic Karenia brevis blooms (a.k.a red tides). Oceanographic conditions measured by the glider were significantly correlated to the variation in sounds from six known or suspected species of fish across the three missions with depth consistently being the most significant factor. At the time and space scales of this study, there was no detectable effect of red tide on sound production. Sounds were still recorded within red tide-affected waters from species with overlapping depth ranges. These results suggest that the fishes studied here did not alter their sound production nor migrate out of red tide-affected areas. Although these results are preliminary because of the limited measurements, the data and methods presented here provide a proof of principle and could serve as protocol for future studies on the effects of algal blooms on the behavior of soniferous fishes. To fully capture the effects of episodic events, we suggest that stationary or vertically profiling acoustic recorders and environmental sampling be used as a complement to glider measurements. PMID:25551564

  19. Production and characterization of an extracellular lipase from Candida guilliermondii

    PubMed Central

    Oliveira, Anne Caroline Defranceschi; Fernandes, Maria Luiza; Mariano, André Bellin

    2014-01-01

    Extracellular lipases from the endophytic yeast Candida guilliermondii isolated from castor leaves (Ricinus communis L.) were produced using low-cost raw materials such as agro-industrial residues and applying them in the esterification of oleic acid for evaluating their potential use in biodiesel production. After partial purification using ammonium sulfate, the enzyme was characterized and presented higher activity (26.8 ± 1.5 U mL−1) in the presence of 5 mmol L−1 NaCl at 30 °C and pH 6.5. The production through submerged fermentation was formerly performed in 150 mL erlenmeyer flasks and, once the enzyme production was verified, assays in a 14 L bioreactor were conducted, obtaining 18 ± 1.4 U mL−1. The produced enzyme was applied in the oleic acid esterification under different solvents: hexane, cyclohexane or cyclohexanone) and different acid:alcohol molar ratios. Higher ester conversion rate (81%) was obtained using hexane and the molar ratio of 1:9 was the best conditions using methanol. The results suggest the potential for development of endophytic yeast in the production of biocatalyst through submerged fermentation using agroindustrial residues as culture medium. PMID:25763060

  20. Production of a polyester degrading extracellular hydrolase from Thermomonospora fusca.

    PubMed

    Gouda, Mona K; Kleeberg, Ilona; van den Heuvel, Joop; Müller, Rolf-Joachim; Deckwer, Wolf-Dieter

    2002-01-01

    The production of a polyester-degrading hydrolase from the thermophilic actinomycete Thermomonospora fusca was investigated with regard to its potential technical application. Only in the presence of a polyester (random aliphatic-aromatic copolyester from 1,4-butanediol, terephthalic acid, and adipic acid with around 40-50 mol % terephthalic acid in the acid component), the excretion of the extracellular enzyme could be achieved with an optimized synthetic medium using pectin and NH(4)Cl as nitrogen source. Compared to complex media, a significantly higher specific activity at comparable volumetric yields could be obtained, thus reducing the expenditure for purification. The activity profile in the medium is controlled by a complex process involving (1) induction of enzyme excretion, (2) enzyme adsorption on the hydrophobic polyester surface, (3) inhibition of enzyme generation by monomers produced by polyester cleavage, and (4) enzyme denaturation. Diafiltration with cellulose acetate membranes as the sole downstream processing step led to a product of high purity and with sufficient yield (60% of total activity). Scaling-up from shaking flasks to a fermentor scale of 100 L revealed no specific problems. However, the excretion of the hydrolase by the actinomycete turned out to be inhibited by the degradation products (monomers) of the aliphatic-aromatic copolyester used as inductor for the enzyme production. The crude enzyme exhibited generally similar properties (temperature and pH optimum) as the highly purified hydrolase described previously; however, the storage capability and thermal stability is improved when the crude enzyme solution is diafiltrated.

  1. Sea-ice algal primary production and nitrogen uptake rates off East Antarctica

    NASA Astrophysics Data System (ADS)

    Roukaerts, Arnout; Cavagna, Anne-Julie; Fripiat, François; Lannuzel, Delphine; Meiners, Klaus M.; Dehairs, Frank

    2016-09-01

    Antarctic pack ice comprises about 90% of the sea ice in the southern hemisphere and plays an important structuring role in Antarctic marine ecosystems, yet measurements of ice algal primary production and nitrogen uptake rates remain scarce. During the early austral spring of 2012, measurements for primary production rates and uptake of two nitrogen substrates (nitrate and ammonium) were conducted at 5 stations in the East Antarctic pack ice (63-66°S, 115-125°E). Carbon uptake was low (3.52 mg C m-2 d-1) but a trend of increased production was observed towards the end of the voyage suggesting pre-bloom conditions. Significant snow covers reaching, up to 0.8 m, induced strong light limitation. Two different regimes were observed in the ice with primarily nitrate based 'new' production (f-ratio: 0.80-0.95) at the bottom of the ice cover, due to nutrient-replete conditions at the ice-water interface, and common for pre-bloom conditions. In the sea-ice interior, POC:PN ratios (20-70) and higher POC:Chl a ratios suggested the presence of large amounts of detrital material trapped in the ice and here ammonium was the prevailing nitrogen substrate. This suggests that most primary production in the sea-ice interior was regenerated and supported by a microbial food web, recycling detritus.

  2. Characterization of Amoeboaphelidium protococcarum, an algal parasite new to the cryptomycota isolated from an outdoor algal pond used for the production of biofuel.

    PubMed

    Letcher, Peter M; Lopez, Salvador; Schmieder, Robert; Lee, Philip A; Behnke, Craig; Powell, Martha J; McBride, Robert C

    2013-01-01

    Mass culture of algae for the production of biofuels is a developing technology designed to offset the depletion of fossil fuel reserves. However, large scale culture of algae in open ponds can be challenging because of incidences of infestation with algal parasites. Without knowledge of the identity of the specific parasite and how to control these pests, algal-based biofuel production will be limited. We have characterized a eukaryotic parasite of Scenedesmus dimorphus growing in outdoor ponds used for biofuel production. We demonstrated that as the genomic DNA of parasite FD01 increases, the concentration of S. dimorphus cells decreases; consequently, this is a highly destructive pathogen. Techniques for culture of the parasite and host were developed, and the endoparasite was identified as the Aphelidea, Amoeboaphelidium protococcarum. Phylogenetic analysis of ribosomal sequences revealed that parasite FD01 placed within the recently described Cryptomycota, a poorly known phylum based on two species of Rozella and environmental samples. Transmission electron microscopy demonstrated that aplanospores of the parasite produced filose pseudopodia, which contained fine fibers the diameter of actin microfilaments. Multiple lipid globules clustered and were associated with microbodies, mitochondria and a membrane cisternae, an arrangement characteristic of the microbody-lipid globule complex of chytrid zoospores. After encystment and attachment to the host cells, the parasite injected its protoplast into the host between the host cell wall and plasma membrane. At maturity the unwalled parasite occupied the entire host cell. After cleavage of the protoplast into aplanospores, a vacuole and lipids remained in the host cell. Amoeboaphelidium protococcarum isolate FD01 is characteristic of the original description of this species and is different from strain X-5 recently characterized. Our results help put a face on the Cryptomycota, revealing that the phylum is more

  3. Efficient production and enhanced tumor delivery of engineered extracellular vesicles.

    PubMed

    Watson, Dionysios C; Bayik, Defne; Srivatsan, Avinash; Bergamaschi, Cristina; Valentin, Antonio; Niu, Gang; Bear, Jenifer; Monninger, Mitchell; Sun, Mei; Morales-Kastresana, Aizea; Jones, Jennifer C; Felber, Barbara K; Chen, Xiaoyuan; Gursel, Ihsan; Pavlakis, George N

    2016-10-01

    Extracellular vesicles (EV), including exosomes and microvesicles, are nano-sized intercellular communication vehicles that participate in a multitude of physiological processes. Due to their biological properties, they are also promising candidates for the systemic delivery of therapeutic compounds, such as cytokines, chemotherapeutic drugs, siRNAs and viral vectors. However, low EV production yield and rapid clearance of administered EV by liver macrophages limit their potential use as therapeutic vehicles. We have used a hollow-fiber bioreactor for the efficient production of bioactive EV bearing the heterodimeric cytokine complex Interleukin-15:Interleukin-15 receptor alpha. Bioreactor culture yielded ∼40-fold more EV per mL conditioned medium, as compared to conventional cell culture. Biophysical analysis and comparative proteomics suggested a more diverse population of EV in the bioreactor preparations, while serum protein contaminants were detectable only in conventional culture EV preparations. We also identified the Scavenger Receptor Class A family (SR-A) as a novel monocyte/macrophage uptake receptor for EV. In vivo blockade of SR-A with dextran sulfate dramatically decreased EV liver clearance in mice, while enhancing tumor accumulation. These findings facilitate development of EV therapeutic methods. PMID:27522254

  4. Production, purification, and characterization of an extracellular chitosanase from Streptomyces.

    PubMed Central

    Price, J S; Storck, R

    1975-01-01

    The synthesis by Streptomyces sp. no. 6 of an extracellular chitosanase was induced by glucosamine. The enzyme was purified to homogeneity by Sephadex G-100, carboxymethyl-cellulose, and diethylaminoethyl-cellulose chromatography. The purified enzyme hydrolyzed chitosan (the beta-1,4-linked polymer of glucosamine) but not chitin nor carboxymethyl-cellulose. The only products of the hydrolysis detectable by paper chromatography were di- and triglucosamine. Sephadex G-100 chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the molecular weight of the enzyme was between 29,000 and 26,000. Acid hydrolysates of the enzyme contained no cysteic acid or glucosamine or other carbohydrate. At 25 C, maximum activity was obtained between pH 4.5 and 6.5. The enzymatic hydrolysis of chitosan occurred over a wide range of temperatures and was maximal at 60 C. The rate of the reaction was inhibited by concentrations of soluble chitosan higher than 0.5 g/liter. The apparent Km calculated from a Lineweaver-Burke plot was 0.688 g/liter at pH 5.5. The enzyme prevented spore germination and caused a significant decrease in the turbidity of germinated spore suspensions of the Mucor strains tested. Such a decrease was the result of a partial lysis of the cell wall. Images PMID:371

  5. Quercetin Attenuates Lactate Production and Extracellular Matrix Secretion in Keratoconus

    PubMed Central

    McKay, T. B.; Lyon, D.; Sarker-Nag, A.; Priyadarsini, S.; Asara, J. M.; Karamichos, D.

    2015-01-01

    Keratoconus(KC) is an ecstatic corneal disease leading to corneal-thinning and the formation of a cone-like cornea. Elevated lactate levels, increased oxidative stress, and myofibroblast formation have all been previously reported. In the current study, we assess the role of Quercetin on collagen secretion and myofibroblast formation in KC in vitro. Human corneal fibroblasts(HCFs) and human keratoconus cells(HKCs) were treated with a stable Vitamin C derivative and cultured for 4 weeks, stimulating formation of a self-assembled extracellular matrix. All samples were analyzed using Western blots and targeted tandem mass spectrometry. Our data showed that Quercetin significantly down regulates myofibroblast differentiation and fibrotic markers, such as α-smooth muscle actin (α-SMA) and Collagen III (Col III), in both HCFs and HKCs. Collagen III secretion was reduced 80% in both HCFs and HKCs following Quercetin treatment. Furthermore, Quercetin reduced lactate production by HKCs to normal HCF levels. Quercetin down regulated TGF-βR2 and TGF-β2 expression in HKCs suggesting a significant link to the TGF-β pathway. These results assert that Quercetin is a key regulator of fibrotic markers and ECM assembly by modulating cellular metabolism and TGF-β signaling. Our study suggests that Quercetin is a potential therapeutic for treatment of corneal dystrophies, such as KC. PMID:25758533

  6. Oil crop biomass residue-based media for enhanced algal lipid production.

    PubMed

    Wang, Zhen; Ma, Xiaochen; Zhou, Wenguang; Min, Min; Cheng, Yanling; Chen, Paul; Shi, Jian; Wang, Qin; Liu, Yuhuan; Ruan, Roger

    2013-10-01

    The aim of this study was to evaluate the use of hydrolysates from acid hydrolysis of four different oil crop biomass residues (OCBR) as low cost culture media for algae growth. The one-factor-at-a-time method was used to design a series of experiments to optimize the acid hydrolysis conditions through examining the total nitrogen, total phosphorus, chemical oxygen demand, and ammonia nitrogen in the hydrolysates. The optimal conditions were found to be using 3% sulfuric acid and hydrolyzing residues at 90 °C for 20 h. The hydrolysates (OCBR media) produced under the optimal conditions were used to cultivate the two algae strains, namely UM258 and UM268. The results from 5 days of cultivation showed that the OCBR media supported faster algae growth with maximal algal biomass yield of 2.7 and 3 g/L, respectively. Moreover, the total lipids for UM258 and UM268 were 54 and 35%, respectively, after 5 days of cultivation, which suggested that the OCBR media allowed the algae strains to accumulate higher lipids probably due to high C/N ratio. Furthermore, over 3% of omega-3 fatty acid (EPA) was produced for the two algae strains. In conclusion, OCBR media are excellent alternative for algae growth and have a great potential for large-scale production of algae-based ingredients for biodiesel as well as high-value food and pharmaceutical products.

  7. Coral–algal phase shifts alter fish communities and reduce fisheries production

    PubMed Central

    Ainsworth, Cameron H; Mumby, Peter J

    2015-01-01

    Anthropogenic stress has been shown to reduce coral coverage in ecosystems all over the world. A phase shift towards an algae-dominated system may accompany coral loss. In this case, the composition of the reef-associated fish assemblage will change and human communities relying on reef fisheries for income and food security may be negatively impacted. We present a case study based on the Raja Ampat Archipelago in Eastern Indonesia. Using a dynamic food web model, we simulate the loss of coral reefs with accompanied transition towards an algae-dominated state and quantify the likely change in fish populations and fisheries productivity. One set of simulations represents extreme scenarios, including 100% loss of coral. In this experiment, ecosystem changes are driven by coral loss itself and a degree of habitat dependency by reef fish is assumed. An alternative simulation is presented without assumed habitat dependency, where changes to the ecosystem are driven by historical observations of reef fish communities when coral is lost. The coral–algal phase shift results in reduced biodiversity and ecosystem maturity. Relative increases in the biomass of small-bodied fish species mean higher productivity on reefs overall, but much reduced landings of traditionally targeted species. PMID:24953835

  8. Coral-algal phase shifts alter fish communities and reduce fisheries production.

    PubMed

    Ainsworth, Cameron H; Mumby, Peter J

    2015-01-01

    Anthropogenic stress has been shown to reduce coral coverage in ecosystems all over the world. A phase shift towards an algae-dominated system may accompany coral loss. In this case, the composition of the reef-associated fish assemblage will change and human communities relying on reef fisheries for income and food security may be negatively impacted. We present a case study based on the Raja Ampat Archipelago in Eastern Indonesia. Using a dynamic food web model, we simulate the loss of coral reefs with accompanied transition towards an algae-dominated state and quantify the likely change in fish populations and fisheries productivity. One set of simulations represents extreme scenarios, including 100% loss of coral. In this experiment, ecosystem changes are driven by coral loss itself and a degree of habitat dependency by reef fish is assumed. An alternative simulation is presented without assumed habitat dependency, where changes to the ecosystem are driven by historical observations of reef fish communities when coral is lost. The coral-algal phase shift results in reduced biodiversity and ecosystem maturity. Relative increases in the biomass of small-bodied fish species mean higher productivity on reefs overall, but much reduced landings of traditionally targeted species.

  9. Coral-algal phase shifts alter fish communities and reduce fisheries production.

    PubMed

    Ainsworth, Cameron H; Mumby, Peter J

    2015-01-01

    Anthropogenic stress has been shown to reduce coral coverage in ecosystems all over the world. A phase shift towards an algae-dominated system may accompany coral loss. In this case, the composition of the reef-associated fish assemblage will change and human communities relying on reef fisheries for income and food security may be negatively impacted. We present a case study based on the Raja Ampat Archipelago in Eastern Indonesia. Using a dynamic food web model, we simulate the loss of coral reefs with accompanied transition towards an algae-dominated state and quantify the likely change in fish populations and fisheries productivity. One set of simulations represents extreme scenarios, including 100% loss of coral. In this experiment, ecosystem changes are driven by coral loss itself and a degree of habitat dependency by reef fish is assumed. An alternative simulation is presented without assumed habitat dependency, where changes to the ecosystem are driven by historical observations of reef fish communities when coral is lost. The coral-algal phase shift results in reduced biodiversity and ecosystem maturity. Relative increases in the biomass of small-bodied fish species mean higher productivity on reefs overall, but much reduced landings of traditionally targeted species. PMID:24953835

  10. Effects of iron on growth, antioxidant enzyme activity, bound extracellular polymeric substances and microcystin production of Microcystis aeruginosa FACHB-905.

    PubMed

    Wang, Chao; Wang, Xun; Wang, Peifang; Chen, Bin; Hou, Jun; Qian, Jin; Yang, Yangyang

    2016-10-01

    Toxic cyanobacterial blooms have occurred in various water bodies during recent decades and made serious health hazards to plants, animals and humans. Iron is an important micronutrient for algal growth and recently, the concentration of which has increased remarkably in freshwaters. In this paper, the cyanobacterium Microcystis aeruginosa FACHB-905 was cultivated under non-iron (0μM), iron-limited (10μM) and iron-replete (100μM) conditions to investigate the effects of iron on growth, antioxidant enzyme activity, EPS and microcystin production. The results showed that algal cell density and chlorophyll-a content were maximal at the highest iron concentration. Antioxidant enzymes activity increased notably under all three conditions in the early stage of experiment, of which the SOD activity recovered soon from oxidative stress in 10μM group. The productions of some protein-like substances and humic acid-like substances of bound EPS were inhibited in iron-containing groups in the early stage of experiment while promoted after the adaptation period of Microcystis aeruginosa. Iron addition is a factor affecting the formation of cyanobacterial blooms through its impact on the content of LB-EPS and the composition of TB-EPS. The intracellular MC-LR concentration and the productivity potential of MC-LR were the lowest in 0μM group and highest in 10μM group. No obvious extracellular release of MC-LR was observed during the cultivation time. Therefore, iron addition can promote the physiological activities of M. aeruginosa, but a greater harm could be brought into environment under iron-limited (10μM) condition than under iron-replete (100μM) condition. PMID:27337497

  11. Effects of iron on growth, antioxidant enzyme activity, bound extracellular polymeric substances and microcystin production of Microcystis aeruginosa FACHB-905.

    PubMed

    Wang, Chao; Wang, Xun; Wang, Peifang; Chen, Bin; Hou, Jun; Qian, Jin; Yang, Yangyang

    2016-10-01

    Toxic cyanobacterial blooms have occurred in various water bodies during recent decades and made serious health hazards to plants, animals and humans. Iron is an important micronutrient for algal growth and recently, the concentration of which has increased remarkably in freshwaters. In this paper, the cyanobacterium Microcystis aeruginosa FACHB-905 was cultivated under non-iron (0μM), iron-limited (10μM) and iron-replete (100μM) conditions to investigate the effects of iron on growth, antioxidant enzyme activity, EPS and microcystin production. The results showed that algal cell density and chlorophyll-a content were maximal at the highest iron concentration. Antioxidant enzymes activity increased notably under all three conditions in the early stage of experiment, of which the SOD activity recovered soon from oxidative stress in 10μM group. The productions of some protein-like substances and humic acid-like substances of bound EPS were inhibited in iron-containing groups in the early stage of experiment while promoted after the adaptation period of Microcystis aeruginosa. Iron addition is a factor affecting the formation of cyanobacterial blooms through its impact on the content of LB-EPS and the composition of TB-EPS. The intracellular MC-LR concentration and the productivity potential of MC-LR were the lowest in 0μM group and highest in 10μM group. No obvious extracellular release of MC-LR was observed during the cultivation time. Therefore, iron addition can promote the physiological activities of M. aeruginosa, but a greater harm could be brought into environment under iron-limited (10μM) condition than under iron-replete (100μM) condition.

  12. Process development for the production of bioethanol from waste algal biomass of Gracilaria verrucosa.

    PubMed

    Shukla, Rishikesh; Kumar, Manoj; Chakraborty, Subhojit; Gupta, Rishi; Kumar, Savindra; Sahoo, Dinabandhu; Kuhad, Ramesh Chander

    2016-11-01

    The algal biomass of different species of Gracilaria were collected from coasts of Orissa and Tamil Nadu, India and characterized biochemically. Among various species, G. verrucosa was found to be better in terms of total carbohydrate content (56.65%) and hence selected for further studies. The agar was extracted from algal biomass and the residual pulp was enzymatically hydrolyzed. The optimization of algal pulp hydrolysis for various parameters revealed a maximum sugar release of 75.8mg/ml with 63% saccharification yield. The fermentation of enzymatic hydrolysate of algal pulp was optimized and 8% (v/v) inoculum size, 12h inoculum age, pH 5.0 were found to be optimum parameters for maximum ethanol concentration (27.2g/L) after 12h. The process of enzymatic hydrolysis and fermentation were successfully scaled up to 2L bioreactor scale. PMID:27619709

  13. Process development for the production of bioethanol from waste algal biomass of Gracilaria verrucosa.

    PubMed

    Shukla, Rishikesh; Kumar, Manoj; Chakraborty, Subhojit; Gupta, Rishi; Kumar, Savindra; Sahoo, Dinabandhu; Kuhad, Ramesh Chander

    2016-11-01

    The algal biomass of different species of Gracilaria were collected from coasts of Orissa and Tamil Nadu, India and characterized biochemically. Among various species, G. verrucosa was found to be better in terms of total carbohydrate content (56.65%) and hence selected for further studies. The agar was extracted from algal biomass and the residual pulp was enzymatically hydrolyzed. The optimization of algal pulp hydrolysis for various parameters revealed a maximum sugar release of 75.8mg/ml with 63% saccharification yield. The fermentation of enzymatic hydrolysate of algal pulp was optimized and 8% (v/v) inoculum size, 12h inoculum age, pH 5.0 were found to be optimum parameters for maximum ethanol concentration (27.2g/L) after 12h. The process of enzymatic hydrolysis and fermentation were successfully scaled up to 2L bioreactor scale.

  14. Natural Product Anacardic Acid from Cashew Nut Shells Stimulates Neutrophil Extracellular Trap Production and Bactericidal Activity.

    PubMed

    Hollands, Andrew; Corriden, Ross; Gysler, Gabriela; Dahesh, Samira; Olson, Joshua; Raza Ali, Syed; Kunkel, Maya T; Lin, Ann E; Forli, Stefano; Newton, Alexandra C; Kumar, Geetha B; Nair, Bipin G; Perry, J Jefferson P; Nizet, Victor

    2016-07-01

    Emerging antibiotic resistance among pathogenic bacteria is an issue of great clinical importance, and new approaches to therapy are urgently needed. Anacardic acid, the primary active component of cashew nut shell extract, is a natural product used in the treatment of a variety of medical conditions, including infectious abscesses. Here, we investigate the effects of this natural product on the function of human neutrophils. We find that anacardic acid stimulates the production of reactive oxygen species and neutrophil extracellular traps, two mechanisms utilized by neutrophils to kill invading bacteria. Molecular modeling and pharmacological inhibitor studies suggest anacardic acid stimulation of neutrophils occurs in a PI3K-dependent manner through activation of surface-expressed G protein-coupled sphingosine-1-phosphate receptors. Neutrophil extracellular traps produced in response to anacardic acid are bactericidal and complement select direct antimicrobial activities of the compound. PMID:27226531

  15. Natural Product Anacardic Acid from Cashew Nut Shells Stimulates Neutrophil Extracellular Trap Production and Bactericidal Activity.

    PubMed

    Hollands, Andrew; Corriden, Ross; Gysler, Gabriela; Dahesh, Samira; Olson, Joshua; Raza Ali, Syed; Kunkel, Maya T; Lin, Ann E; Forli, Stefano; Newton, Alexandra C; Kumar, Geetha B; Nair, Bipin G; Perry, J Jefferson P; Nizet, Victor

    2016-07-01

    Emerging antibiotic resistance among pathogenic bacteria is an issue of great clinical importance, and new approaches to therapy are urgently needed. Anacardic acid, the primary active component of cashew nut shell extract, is a natural product used in the treatment of a variety of medical conditions, including infectious abscesses. Here, we investigate the effects of this natural product on the function of human neutrophils. We find that anacardic acid stimulates the production of reactive oxygen species and neutrophil extracellular traps, two mechanisms utilized by neutrophils to kill invading bacteria. Molecular modeling and pharmacological inhibitor studies suggest anacardic acid stimulation of neutrophils occurs in a PI3K-dependent manner through activation of surface-expressed G protein-coupled sphingosine-1-phosphate receptors. Neutrophil extracellular traps produced in response to anacardic acid are bactericidal and complement select direct antimicrobial activities of the compound.

  16. Salt stress represses production of extracellular proteases in Bacillus pumilus.

    PubMed

    Liu, R F; Huang, C L; Feng, H

    2015-05-11

    Bacillus pumilus is able to secrete subtilisin-like prote-ases, one of which has been purified and characterized biochemically, demonstrating great potential for use in industrial applications. In the current study, the biosynthesis and transcription of extracellular pro-teases in B. pumilus (BA06) under salt stress were investigated using various methods, including a proteolytic assay, zymogram analysis, and real-time PCR. Our results showed that total extracellular proteolytic activity, both in fermentation broth and on milk-containing agar plates, was considerably repressed by salt in a dosage-dependent manner. As Bacillus species usually secret multiple extracellular proteases, a vari-ety of individual extracellular protease encoding genes were selected for real-time PCR analysis. It was shown that proteases encoded by the aprE and aprX genes were the major proteases in the fermentation broth in terms of their transcripts in B. pumilus. Further, transcription of aprE, aprX, and epr genes was indeed repressed by salt stress. In con-trast, transcription of other genes (e.g., vpr and wprA) was not repressed or significantly affected by the salt. Conclusively, salt stress represses total extracellular proteolytic activity in B. pumilus, which can largely be ascribed to suppression of the major protease-encoding genes (aprE, aprX) at the transcriptional level. In contrast, transcription of other pro-tease-encoding genes (e.g., vpr, wprA) was not repressed by salt stress.

  17. Direct utilization of waste water algal biomass for ethanol production by cellulolytic Clostridium phytofermentans DSM1183.

    PubMed

    Fathima, Anwar Aliya; Sanitha, Mary; Kumar, Thangarathinam; Iyappan, Sellamuthu; Ramya, Mohandass

    2016-02-01

    Direct bioconversion of waste water algal biomass into ethanol using Clostridium phytofermentans DSM1183 was demonstrated in this study. Fermentation of 2% (w/v) autoclaved algal biomass produced ethanol concentration of 0.52 g L(-1) (solvent yield of 0.19 g/g) where as fermentation of acid pretreated algal biomass (2%, w/v) produced ethanol concentration of 4.6 g L(-1) in GS2 media (solvent yield of 0.26 g/g). The control experiment with 2% (w/v) glucose in GS2 media produced ethanol concentration of 2.8 g L(-1) (solvent yield of 0.25 g/g). The microalgal strains from waste water algal biomass were identified as Chlamydomonas dorsoventralis, Graesiella emersonii, Coelastrum proboscideum, Scenedesmus obliquus, Micractinium sp., Desmodesmus sp., and Chlorella sp., based on ITS-2 molecular marker. The presence of glucose, galactose, xylose and rhamnose were detected by high performance liquid chromatography in the algal biomass. Scanning Electron Microscopy observations of fermentation samples showed characteristic morphological changes in algal cells and bioaccessibility of C. phytofermentans.

  18. Simultaneous wastewater treatment, electricity generation and biomass production by an immobilized photosynthetic algal microbial fuel cell.

    PubMed

    He, Huanhuan; Zhou, Minghua; Yang, Jie; Hu, Youshuang; Zhao, Yingying

    2014-05-01

    A photosynthetic algal microbial fuel cell (PAMFC) was constructed by the introduction of immobilized microalgae (Chlorella vulgaris) into the cathode chamber of microbial fuel cells to fulfill electricity generation, biomass production and wastewater treatment. The immobilization conditions, including the concentration of immobilized matrix, initial inoculation concentration and cross-linking time, were investigated both for the growth of C. vulgaris and power generation. It performed the best at 5 % sodium alginate and 2 % calcium chloride as immobilization matrix, initial inoculation concentration of 10(6) cell/mL and cross-linking time of 4 h. Our findings indicated that C. vulgaris immobilization was an effective and promising approach to improve the performance of PAMFC, and after optimization the power density and Coulombic efficiency improved by 258 and 88.4 %, respectively. Important parameters such as temperature and light intensity were optimized on the performance. PAMFC could achieve a COD removal efficiency of 92.1 %, and simultaneously the maximum power density reached 2,572.8 mW/m(3) and the Coulombic efficiency was 14.1 %, under the light intensity of 5,000 lux and temperature at 25 °C.

  19. Optical microplates for photonic high throughput screening of algal photosynthesis and biofuel production.

    PubMed

    Mertiri, Taulant; Chen, Meng; Holland, Thomas; Basu, Amar S

    2011-01-01

    Biological systems respond not only to chemical stimuli (drugs, proteins) but also to physical stimuli (light, heat, stress). Though there are many high throughput tools for screening chemical stimuli, no such tool exists for screening of physical stimuli. This paper presents a novel instrument for photonic high throughput screening of photosynthesis, a light-driven bioprocess. The optical microplate has a footprint identical to a standard 96 well plate, and it provides temporal and intensity control of light in each individual well. Intensity control provides 128 dimming levels (7-bit resolution), with maximum intensity 120 mE/cm(2). Temporal modulation, used for studying dynamics and regulation of photosynthesis, can be as low as 10 μs. We used photonic screening for high throughput studies of algal growth rates and photosynthetic efficiency, using the model organism Dunaliella tertiolecta, a lipid producing algae of interest in biofuel production. Due to the ability to conduct 96 studies in parallel, experiments that would require 2 years using conventional tools can be completed in 1 week. This instrument opens up novel high throughput protocols for photobiology and the growing field of phenomics.

  20. Consuming algal products: trophic interactions of bacteria and a diatom species determined by RNA stable isotope probing

    NASA Astrophysics Data System (ADS)

    Sapp, Melanie; Gerdts, Gunnar; Wellinger, Marco; Wichels, Antje

    2008-09-01

    Heterotrophic marine bacteria utilise a wide range of carbon sources. Recently, techniques were developed to link bacterial identity and physiological capacity of microorganisms within natural communities. One of these methods is stable isotope probing (SIP) which allows an identification of active microorganisms using particular growth substrates. In this study, we present the first attempt to analyse bacterial communities associated with microalgae by rRNA-SIP. This approach was used to analyse bacterial populations consuming algal products of Thalassiosira rotula by applying SIP followed by reverse transcription of 16S rRNA and denaturing gradient gel electrophoresis. Generally, our results indicate that bacteria which consume algal products can be detected by isotope arrays coupled with fingerprinting methods.

  1. Algal photosynthesis as the primary driver for a sustainable development in energy, feed, and food production.

    PubMed

    Anemaet, Ida G; Bekker, Martijn; Hellingwerf, Klaas J

    2010-11-01

    High oil prices and global warming that accompany the use of fossil fuels are an incentive to find alternative forms of energy supply. Photosynthetic biofuel production represents one of these since for this, one uses renewable resources. Sunlight is used for the conversion of water and CO₂ into biomass. Two strategies are used in parallel: plant-based production via sugar fermentation into ethanol and biodiesel production through transesterification. Both, however, exacerbate other problems, including regional nutrient balancing and the world's food supply, and suffer from the modest efficiency of photosynthesis. Maximizing the efficiency of natural and engineered photosynthesis is therefore of utmost importance. Algal photosynthesis is the system of choice for this particularly for energy applications. Complete conversion of CO₂ into biomass is not necessary for this. Innovative methods of synthetic biology allow one to combine photosynthetic and fermentative metabolism via the so-called Photanol approach to form biofuel directly from Calvin cycle intermediates through use of the naturally transformable cyanobacterium Synechocystis sp. PCC 6803. Beyond providing transport energy and chemical feedstocks, photosynthesis will continue to be used for food and feed applications. Also for this application, arguments of efficiency will become more and more important as the size of the world population continues to increase. Photosynthetic cells can be used for food applications in various innovative forms, e.g., as a substitute for the fish proteins in the diet supplied to carnivorous fish or perhaps--after acid hydrolysis--as a complex, animal-free serum for growth of mammalian cells in vitro.

  2. Algal Photosynthesis as the Primary Driver for a Sustainable Development in Energy, Feed, and Food Production

    PubMed Central

    Anemaet, Ida G.; Bekker, Martijn

    2010-01-01

    High oil prices and global warming that accompany the use of fossil fuels are an incentive to find alternative forms of energy supply. Photosynthetic biofuel production represents one of these since for this, one uses renewable resources. Sunlight is used for the conversion of water and CO2 into biomass. Two strategies are used in parallel: plant-based production via sugar fermentation into ethanol and biodiesel production through transesterification. Both, however, exacerbate other problems, including regional nutrient balancing and the world's food supply, and suffer from the modest efficiency of photosynthesis. Maximizing the efficiency of natural and engineered photosynthesis is therefore of utmost importance. Algal photosynthesis is the system of choice for this particularly for energy applications. Complete conversion of CO2 into biomass is not necessary for this. Innovative methods of synthetic biology allow one to combine photosynthetic and fermentative metabolism via the so-called Photanol approach to form biofuel directly from Calvin cycle intermediates through use of the naturally transformable cyanobacterium Synechocystis sp. PCC 6803. Beyond providing transport energy and chemical feedstocks, photosynthesis will continue to be used for food and feed applications. Also for this application, arguments of efficiency will become more and more important as the size of the world population continues to increase. Photosynthetic cells can be used for food applications in various innovative forms, e.g., as a substitute for the fish proteins in the diet supplied to carnivorous fish or perhaps—after acid hydrolysis—as a complex, animal-free serum for growth of mammalian cells in vitro. PMID:20640935

  3. Enhanced energy conversion efficiency from high strength synthetic organic wastewater by sequential dark fermentative hydrogen production and algal lipid accumulation.

    PubMed

    Ren, Hong-Yu; Liu, Bing-Feng; Kong, Fanying; Zhao, Lei; Xing, Defeng; Ren, Nan-Qi

    2014-04-01

    A two-stage process of sequential dark fermentative hydrogen production and microalgal cultivation was applied to enhance the energy conversion efficiency from high strength synthetic organic wastewater. Ethanol fermentation bacterium Ethanoligenens harbinense B49 was used as hydrogen producer, and the energy conversion efficiency and chemical oxygen demand (COD) removal efficiency reached 18.6% and 28.3% in dark fermentation. Acetate was the main soluble product in dark fermentative effluent, which was further utilized by microalga Scenedesmus sp. R-16. The final algal biomass concentration reached 1.98gL(-1), and the algal biomass was rich in lipid (40.9%) and low in protein (23.3%) and carbohydrate (11.9%). Compared with single dark fermentation stage, the energy conversion efficiency and COD removal efficiency of two-stage system remarkably increased 101% and 131%, respectively. This research provides a new approach for efficient energy production and wastewater treatment using a two-stage process combining dark fermentation and algal cultivation.

  4. Evaluating the relative impacts of operational and financial factors on the competitiveness of an algal biofuel production facility.

    PubMed

    Hise, Adam M; Characklis, Gregory W; Kern, Jordan; Gerlach, Robin; Viamajala, Sridhar; Gardner, Robert D; Vadlamani, Agasteswar

    2016-11-01

    Algal biofuels are becoming more economically competitive due to technological advances and government subsidies offering tax benefits and lower cost financing. These factors are linked, however, as the value of technical advances is affected by modeling assumptions regarding the growth conditions, process design, and financing of the production facility into which novel techniques are incorporated. Two such techniques, related to algal growth and dewatering, are evaluated in representative operating and financing scenarios using an integrated techno-economic model. Results suggest that these techniques can be valuable under specified conditions, but also that investment subsidies influence cost competitive facility design by incentivizing development of more capital intensive facilities (e.g., favoring hydrothermal liquefaction over transesterification-based facilities). Evaluating novel techniques under a variety of operational and financial scenarios highlights the set of site-specific conditions in which technical advances are most valuable, while also demonstrating the influence of subsidies linked to capital intensity. PMID:27584903

  5. Evaluating the relative impacts of operational and financial factors on the competitiveness of an algal biofuel production facility.

    PubMed

    Hise, Adam M; Characklis, Gregory W; Kern, Jordan; Gerlach, Robin; Viamajala, Sridhar; Gardner, Robert D; Vadlamani, Agasteswar

    2016-11-01

    Algal biofuels are becoming more economically competitive due to technological advances and government subsidies offering tax benefits and lower cost financing. These factors are linked, however, as the value of technical advances is affected by modeling assumptions regarding the growth conditions, process design, and financing of the production facility into which novel techniques are incorporated. Two such techniques, related to algal growth and dewatering, are evaluated in representative operating and financing scenarios using an integrated techno-economic model. Results suggest that these techniques can be valuable under specified conditions, but also that investment subsidies influence cost competitive facility design by incentivizing development of more capital intensive facilities (e.g., favoring hydrothermal liquefaction over transesterification-based facilities). Evaluating novel techniques under a variety of operational and financial scenarios highlights the set of site-specific conditions in which technical advances are most valuable, while also demonstrating the influence of subsidies linked to capital intensity.

  6. Harmful Algal Blooms

    USGS Publications Warehouse

    Graham, Jennifer L.

    2007-01-01

    What are Harmful Algal Blooms (HABs)? Freshwater and marine harmful algal blooms (HABs) can occur anytime water use is impaired due to excessive accumulations of algae. HAB occurrence is affected by a complex set of physical, chemical, biological, hydrological, and meteorological conditions making it difficult to isolate specific causative environmental factors. Potential impairments include reduction in water quality, accumulation of malodorous scums in beach areas, algal production of toxins potent enough to poison both aquatic and terrestrial organisms, and algal production of taste-and-odor compounds that cause unpalatable drinking water and fish. HABs are a global problem, and toxic freshwater and (or) marine algae have been implicated in human and animal illness and death in over 45 countries worldwide and in at least 27 U.S. States (Yoo and others, 1995; Chorus and Bartram, 1999; Huisman and others, 2005).

  7. Producing docosahexaenoic acid (DHA)-rich algae from biodiesel-derived crude glycerol: effects of impurities on DHA production and algal biomass composition.

    PubMed

    Pyle, Denver J; Garcia, Rafael A; Wen, Zhiyou

    2008-06-11

    Crude glycerol is the primary byproduct of the biodiesel industry. Producing docosahexaenoic acid (DHA, 22:6 n-3) through fermentation of the alga Schizochytrium limacinum on crude glycerol provides a unique opportunity to utilize a large quantity of this byproduct. The objective of this work is to investigate the effects of impurities contained in the crude glycerol on DHA production and algal biomass composition. Crude glycerol streams were obtained from different biodiesel refineries. All of the glycerol samples contained methanol, soaps, and various elements including calcium, phosphorus, potassium, silicon, sodium, and zinc. Both methanol and soap were found to negatively influence algal DHA production; these two impurities can be removed from culture medium by evaporation through autoclaving (for methanol) and by precipitation through pH adjustment (for soap). The glycerol-derived algal biomass contained 45-50% lipid, 14-20% protein, and 25% carbohydrate, with 8-13% ash content. Palmitic acid (C16:0) and DHA were the two major fatty acids in the algal lipid. The algal biomass was rich in lysine and cysteine, relative to many common feedstuffs. Elemental analysis by inductively coupled plasma showed that boron, calcium, copper, iron, magnesium, phosphorus, potassium, silicon, sodium, and sulfur were present in the biomass, whereas no heavy metals (such as mercury) were detected in the algal biomass. Overall, the results show that crude glycerol was a suitable carbon source for algal fermentation. The crude glycerol-derived algal biomass had a high level of DHA and a nutritional profile similar to that of commercial algal biomass, suggesting a great potential for using crude glycerol-derived algae in omega-3-fortified food or feed.

  8. Swine manure-based pilot-scale algal biomass production system for fuel production and wastewater treatment--a case study.

    PubMed

    Min, Min; Hu, Bing; Mohr, Michael J; Shi, Aimin; Ding, Jinfeng; Sun, Yong; Jiang, Yongcheng; Fu, Zongqiang; Griffith, Richard; Hussain, Fida; Mu, Dongyan; Nie, Yong; Chen, Paul; Zhou, Wenguang; Ruan, Roger

    2014-02-01

    Integration of wastewater treatment with algae cultivation is one of the promising ways to achieve an economically viable and environmentally sustainable algal biofuel production on a commercial scale. This study focused on pilot-scale algal biomass production system development, cultivation process optimization, and integration with swine manure wastewater treatment. The areal algal biomass productivity for the cultivation system that we developed ranged from 8.08 to 14.59 and 19.15-23.19 g/m(2) × day, based on ash-free dry weight and total suspended solid (TSS), respectively, which were higher than or comparable with those in literature. The harvested algal biomass had lipid content about 1.77-3.55%, which was relatively low, but could be converted to bio-oil via fast microwave-assisted pyrolysis system developed in our lab. The lipids in the harvested algal biomass had a significantly higher percentage of total unsaturated fatty acids than those grown in lab conditions, which may be attributed to the observed temperature and light fluctuations. The nutrient removal rate was highly correlated to the biomass productivity. The NH₃-N, TN, COD, and PO₄-P reduction rates for the north-located photo-bioreactor (PBR-N) in July were 2.65, 3.19, 7.21, and 0.067 g/m(2) × day, respectively, which were higher than those in other studies. The cultivation system had advantages of high mixotrophic growth rate, low operating cost, as well as reduced land footprint due to the stacked-tray bioreactor design used in the study. PMID:24203276

  9. Algal biofuels.

    PubMed

    Razeghifard, Reza

    2013-11-01

    The world is facing energy crisis and environmental issues due to the depletion of fossil fuels and increasing CO2 concentration in the atmosphere. Growing microalgae can contribute to practical solutions for these global problems because they can harvest solar energy and capture CO2 by converting it into biofuel using photosynthesis. Microalgae are robust organisms capable of rapid growth under a variety of conditions including in open ponds or closed photobioreactors. Their reduced biomass compounds can be used as the feedstock for mass production of a variety of biofuels. As another advantage, their ability to accumulate or secrete biofuels can be controlled by changing their growth conditions or metabolic engineering. This review is aimed to highlight different forms of biofuels produced by microalgae and the approaches taken to improve their biofuel productivity. The costs for industrial-scale production of algal biofuels in open ponds or closed photobioreactors are analyzed. Different strategies for photoproduction of hydrogen by the hydrogenase enzyme of green algae are discussed. Algae are also good sources of biodiesel since some species can make large quantities of lipids as their biomass. The lipid contents for some of the best oil-producing strains of algae in optimized growth conditions are reviewed. The potential of microalgae for producing petroleum related chemicals or ready-make fuels such as bioethanol, triterpenic hydrocarbons, isobutyraldehyde, isobutanol, and isoprene from their biomass are also presented.

  10. Opportunities for Switzerland to Contribute to the Production of Algal Biofuels: the Hydrothermal Pathway to Bio-Methane.

    PubMed

    Bagnoud-Velásquez, Mariluz; Refardt, Dominik; Vuille, François; Ludwig, Christian

    2015-01-01

    Microalgae have a significant potential to be a sustainable source of fuel and thus are of interest in the transition to a sustainable energy system, in particular for resource-dependent countries such as Switzerland. Independence of fossil fuels, considerable reduction of CO(2) emissions, and abandoning nuclear energy may be possible with an integrated system approach including the sourcing of biofuels from different types of biomass. Today, a full carbon-to-fuel conversion is possible, and has been recently demonstrated with an advanced hydrothermal technology. The potential to develop algal biofuels is viewed as high thanks to the possibility they offer to uncouple bioenergy from food production. Nevertheless, technological breakthroughs must take place before commercial production becomes a reality, especially to meet the necessary cost savings and efficiency gains in the algae cultivation structure. In addition, an integrated management of waste resources to promote the nutrient recovery appears today as imperative to further improve the economic viability and the environmental sustainability of algal production. We provide here a review that includes the global technological status of both algae production and their conversion into biofuels in order to understand first the added value of algal energy in general before we focus on the potential of algae to contribute specifically to the Swiss energy system to the horizon 2050. In this respect, the hydrothermal conversion pathway of microalgal biomass into synthetic natural gas (SNG) is emphasized, as research into this technology has received considerable attention in Switzerland during the last decade. In addition, SNG is a particularly relevant fuel in the Swiss context due to the existing gas grid and to the opportunity it offers to cover a wide spectrum of energy applications, in particular cogeneration of heat and electricity or use as a transport fuel in the growing gas car fleet. PMID:26598406

  11. Opportunities for Switzerland to Contribute to the Production of Algal Biofuels: the Hydrothermal Pathway to Bio-Methane.

    PubMed

    Bagnoud-Velásquez, Mariluz; Refardt, Dominik; Vuille, François; Ludwig, Christian

    2015-01-01

    Microalgae have a significant potential to be a sustainable source of fuel and thus are of interest in the transition to a sustainable energy system, in particular for resource-dependent countries such as Switzerland. Independence of fossil fuels, considerable reduction of CO(2) emissions, and abandoning nuclear energy may be possible with an integrated system approach including the sourcing of biofuels from different types of biomass. Today, a full carbon-to-fuel conversion is possible, and has been recently demonstrated with an advanced hydrothermal technology. The potential to develop algal biofuels is viewed as high thanks to the possibility they offer to uncouple bioenergy from food production. Nevertheless, technological breakthroughs must take place before commercial production becomes a reality, especially to meet the necessary cost savings and efficiency gains in the algae cultivation structure. In addition, an integrated management of waste resources to promote the nutrient recovery appears today as imperative to further improve the economic viability and the environmental sustainability of algal production. We provide here a review that includes the global technological status of both algae production and their conversion into biofuels in order to understand first the added value of algal energy in general before we focus on the potential of algae to contribute specifically to the Swiss energy system to the horizon 2050. In this respect, the hydrothermal conversion pathway of microalgal biomass into synthetic natural gas (SNG) is emphasized, as research into this technology has received considerable attention in Switzerland during the last decade. In addition, SNG is a particularly relevant fuel in the Swiss context due to the existing gas grid and to the opportunity it offers to cover a wide spectrum of energy applications, in particular cogeneration of heat and electricity or use as a transport fuel in the growing gas car fleet.

  12. National Algal Biofuels Technology Roadmap

    SciTech Connect

    Ferrell, John; Sarisky-Reed, Valerie

    2010-05-01

    The framework for National Algal Biofuels Technology Roadmap was constructed at the Algal Biofuels Technology Roadmap Workshop, held December 9-10, 2008, at the University of Maryland-College Park. The Workshop was organized by the Biomass Program to discuss and identify the critical challenges currently hindering the development of a domestic, commercial-scale algal biofuels industry. This Roadmap presents information from a scientific, economic, and policy perspectives that can support and guide RD&D investment in algal biofuels. While addressing the potential economic and environmental benefits of using algal biomass for the production of liquid transportation fuels, the Roadmap describes the current status of algae RD&D. In doing so, it lays the groundwork for identifying challenges that likely need to be overcome for algal biomass to be used in the production of economically viable biofuels.

  13. Anaerobic co-digestion of pig manure and algae: impact of intracellular algal products recovery on co-digestion performance.

    PubMed

    Astals, S; Musenze, R S; Bai, X; Tannock, S; Tait, S; Pratt, S; Jensen, P D

    2015-04-01

    This paper investigates anaerobic co-digestion of pig manure and algae (Scenedesmus sp.) with and without extraction of intracellular algal co-products, with views towards the development of a biorefinery concept for lipid, protein and/or biogas production. Protein and/or lipids were extracted from Scenedesmus sp. using free nitrous acid pre-treatments and solvent-based Soxhlet extraction, respectively. Processing increased algae methane yield between 29% and 37% compared to raw algae (VS basis), but reduced the amount of algae available for digestion. Co-digestion experiments showed a synergy between pig manure and raw algae that increased raw algae methane yield from 0.163 to 0.245 m(3) CH4 kg(-1)VS. No such synergy was observed when algal residues were co-digested with pig manure. Finally, experimental results were used to develop a high-level concept for an integrated biorefinery processing pig manure and onsite cultivated algae, evaluating methane production and co-product recovery per mass of pig manure entering the refinery.

  14. Exploiting diversity and synthetic biology for the production of algal biofuels.

    PubMed

    Georgianna, D Ryan; Mayfield, Stephen P

    2012-08-16

    Modern life is intimately linked to the availability of fossil fuels, which continue to meet the world's growing energy needs even though their use drives climate change, exhausts finite reserves and contributes to global political strife. Biofuels made from renewable resources could be a more sustainable alternative, particularly if sourced from organisms, such as algae, that can be farmed without using valuable arable land. Strain development and process engineering are needed to make algal biofuels practical and economically viable.

  15. Coupled nutrient removal and biomass production with mixed algal culture: impact of biotic and abiotic factors.

    PubMed

    Su, Yanyan; Mennerich, Artur; Urban, Brigitte

    2012-08-01

    The influence of biotic (algal inoculum concentration) and abiotic factors (illumination cycle, mixing velocity and nutrient strength) on the treatment efficiency, biomass generation and settleability were investigated with selected mixed algal culture. Dark condition led to poor nutrient removal efficiency. No significant difference in the N, P removal and biomass settleability between continuous and alternating illumination was observed, but a higher biomass generation capability for the continuous illumination was obtained. Different mixing velocity led to similar phosphorus removal efficiencies (above 98%) with different retention times. The reactor with 300 rpm mixing velocity had the best N removal capability. For the low strength wastewater, the N rates were 5.4±0.2, 9.1±0.3 and 10.8±0.3 mg/l/d and P removal rates were 0.57±0.03, 0.56±0.03 and 0.72±0.05 mg/l/d for reactors with the algal inoculum concentration of 0.2, 0.5 and 0.8 g/l, respectively. Low nutrient removal efficiency and poor biomass settleability were obtained for high strength wastewater.

  16. Polar coralline algal CaCO3-production rates correspond to intensity and duration of the solar radiation

    NASA Astrophysics Data System (ADS)

    Teichert, S.; Freiwald, A.

    2013-08-01

    In this study we present a comparative quantification of CaCO3 production rates by rhodolith-forming coralline red algal communities situated in high polar latitudes and assess which environmental parameters control these productions rates. The present rhodoliths act as ecosystem engineers and their carbonate skeletons provide an important ecological niche to a variety of benthic organisms. The settings are distributed along the coasts of the Svalbard archipelago, being Floskjeret (78°18' N) in Isfjorden, Krossfjorden (79°08' N) at the eastern coast of Haakon VII Land, Mosselbukta (79°53' N) at the eastern coast of Mosselhalvøya, and Nordkappbukta (80°31' N) at the northern coast of Nordaustlandet. All sites feature Arctic climate and strong seasonality. The algal CaCO3 production rates were calculated from fuchsine stained annual growth increments exhibited by the rhodoliths and range from 100.9 g (CaCO3) m-2 yr-1 at Nordkappbukta to 200.3 g (CaCO3) m-2 yr-1 at Floskjeret. The rates correlate to various environmental parameters with geographical latitude being the most significant (negative correlation, R2 = 0.95, p < 0.05), followed by the duration of the polar night (negative correlation, R2 = 0.93, p < 0.05), the duration of the sea ice cover (negative correlation, R2 = 0.87, p = 0.07), and the annual mean temperature (positive correlation, R2 = 0.48, p < 0.05). This points out sufficient light incidence to be the main control of the growth of the examined coralline red algal rhodolith communities, while temperature is less important. Thus, the ongoing global change with its rising temperatures will most likely result in impaired conditions for the algal, because the concomitant increased global runoff will decrease water transparency and hence light incidence at the four offshore sites. Regarding the aforementioned role of the rhodoliths as ecosystem engineers, the impact on the associated organisms will presumably also be negative.

  17. Production of a specific extracellular inhibitor of TRPM3 channels

    PubMed Central

    Naylor, J; Milligan, C J; Zeng, F; Jones, C; Beech, D J

    2008-01-01

    Background and purpose: Isoform-specific ion channel blockers are useful for target validation in drug discovery and can provide the basis for new therapeutic agents and aid in determination of physiological functions of ion channels. The aim of this study was to generate a specific blocker of human TRPM3 channels as a tool to help investigations of this member of the TRP cationic channel family. Experimental approach: A polyclonal antibody (TM3E3) was made to a conserved peptide of the third extracellular (E3) loop of TRPM3 and tested for binding and functional effect. Studies of channel activity were made by whole-cell planar patch-clamp and fura-2 intracellular Ca2+ measurement. Key results: Ionic current mediated by TRPM3 was inhibited partially by TM3E3 over a period of 5–10 min. Ca2+ entry in TRPM3-expressing cells was also partially inhibited by TM3E3 in a peptide-specific manner and independently of the type of agonist used to activate TRPM3. TM3E3 had no effect on TRPC5, TRPV4, TRPM2 or an endogenous ATP response. Conclusions and implications: The data show the successful development of a specific TRPM3 inhibitor and give further confidence in E3 targeting as an approach to producing isoform-specific ion channel blockers. PMID:18604232

  18. Extracellular Enzyme Production and Synthetic Lignin Mineralization by Ceriporiopsis subvermispora

    PubMed Central

    Rüttimann-Johnson, Carmen; Salas, Loreto; Vicuña, Rafael; Kirk, T. Kent

    1993-01-01

    The ability of the white rot fungus Ceriporiopsis subvermispora to mineralize 14C-synthetic lignin was studied under different culture conditions, and the levels of two extracellular enzymes were monitored. The highest mineralization rates (28% after 28 days) were obtained in cultures containing a growth-limiting amount of nitrogen source (1.0 mM ammonium tartrate); under this condition, the levels of manganese peroxidase (MnP) and laccase present in the culture supernatant solutions were very low compared with cultures containing 10 mM of the nitrogen source. In contrast, cultures containing a limiting concentration of the carbon source (0.1% glucose) showed low levels of both enzymes and also very low mineralization rates compared with cultures containing 1% glucose. Cultures containing 11 ppm of Mn(II) showed a higher rate of mineralization than those containing 0.3 or 40 ppm of this cation. Levels of MnP and laccase were higher when 40 ppm of Mn(II) was used. Mineralization rates were slightly higher in cultures flushed daily with oxygen, whereas laccase levels were lower and MnP levels were approximately the same as in cultures maintained under an air atmosphere. The presence of 0.4 mM veratryl alcohol reduced both mineralization rates and MnP levels, without affecting laccase levels. Lignin peroxidase activity was not detected under any condition. Addition of purified lignin peroxidase to the cultures in the presence or absence of veratryl alcohol did not enhance mineralization rates significantly. PMID:16348955

  19. [Extracellular slime production and adhesion of Morganella morganii strains to polystyrene].

    PubMed

    Michalska, Anna; Zalas-Wiecek, Patrycja; Sielska, Barbara; Gospodarek, Eugenia

    2011-01-01

    The aim of this study was the evaluation of the ability of extracellular slime production and adhesive properties of M. morganii strains. This study included 50 of M. morganii strains isolated from clinical samples. All of these strains were isolated in the Clinical Microbiology Department of dr. A. Jurasz University Hospital in 2008-2009. Five (10.0%) out of 50. M. morganii strains demonstrated extracellular slime production. Adherence to polystyrene revealed 36 (72.0%) of M. morganii strains in it 6 strains (12.0%) adhered strongly, medium - 12 (24.0%) and weakly - 18 (36.0%).

  20. Effects of feeding algal meal high in docosahexaenoic acid on feed intake, milk production, and methane emissions in dairy cows.

    PubMed

    Moate, P J; Williams, S R O; Hannah, M C; Eckard, R J; Auldist, M J; Ribaux, B E; Jacobs, J L; Wales, W J

    2013-05-01

    of milk fatty acids) and conjugated linoleic acid C18:2 cis-9,trans-11 (0.36, 1.09, 1.79, and 1.87 g/100g of milk fatty acids). Addition of DHA did not affect total emissions of CH4 (543, 563, 553, and 520 g/cow per d), nor emissions in terms of milk production (24.9, 22.1, 24.3, and 23.4 g of CH4/kg of milk), but emissions were increased with respect to total intake (22.6, 23.5, 24.5, and 24.4 g of CH4/kg of DM). These findings indicate that CH4 emissions were not reduced when dairy cows were fed a forage-based diet supplemented with DHA from algal meal. PMID:23498011

  1. Extracellular enzyme activities during cassava fermentation for 'fufu' production.

    PubMed

    Oyewole, O B; Odunfa, S A

    1992-01-01

    Amylase and pectin methyl esterase activities increased rapidly during the early period of the fermentation of cassava for 'fufu' production, attaining their peak activities after 12 and 24h, respectively. Cellulase activity was lower and approximately constant for most of the fermentation period.

  2. Extracellular superoxide production, viability and redox poise in response to desiccation in recalcitrant Castanea sativa seeds.

    PubMed

    Roach, Thomas; Beckett, Richard P; Minibayeva, Farida V; Colville, Louise; Whitaker, Claire; Chen, Hongying; Bailly, Christophe; Kranner, Ilse

    2010-01-01

    Reactive oxygen species (ROS) are implicated in seed death following dehydration in desiccation-intolerant 'recalcitrant' seeds. However, it is unknown if and how ROS are produced in the apoplast and if they play a role in stress signalling during desiccation. We studied intracellular damage and extracellular superoxide (O(2)(.-)) production upon desiccation in Castanea sativa seeds, mechanisms of O(2)(.-) production and the effect of exogenously supplied ROS. A transient increase in extracellular O(2)(.-) production by the embryonic axes preceded significant desiccation-induced viability loss. Thereafter, progressively more oxidizing intracellular conditions, as indicated by a significant shift in glutathione half-cell reduction potential, accompanied cell and axis death, coinciding with the disruption of nuclear membranes. Most hydrogen peroxide (H(2)O(2))-dependent O(2)(.-) production was found in a cell wall fraction that contained extracellular peroxidases (ECPOX) with molecular masses of approximately 50 kDa. Cinnamic acid was identified as a potential reductant required for ECPOX-mediated O(2)(.-) production. H(2)O(2), applied exogenously to mimic the transient ROS burst at the onset of desiccation, counteracted viability loss of sub-lethally desiccation-stressed seeds and of excised embryonic axes grown in tissue culture. Hence, extracellular ROS produced by embryonic axes appear to be important signalling components involved in wound response, regeneration and growth.

  3. Statistical optimization of thermal pretreatment conditions for enhanced biomethane production from defatted algal biomass.

    PubMed

    Chandra, T Sarat; Suvidha, G; Mukherji, S; Chauhan, V S; Vidyashankar, S; Krishnamurthi, K; Sarada, R; Mudliar, S N

    2014-06-01

    The present study analyzes the effect of thermal pretreatment for enhancing the biomethane potential of defatted algal biomass of Scenedesmus dimorphus through statistically guided experimental design. To this end, defatted microalgal biomass at various concentrations (1, 3 and 5 g L(-1)) was pretreated at elevated temperatures (100, 120 and 150°C) for 20, 40 and 60 min. The solubilised TOC was favourably enhanced up to 71 mg L(-1) after pretreatment at a temperature of 150°C for reaction time of 60 min. The methane yield was substantially enhanced (up to 60%) and could be correlated with an increase in organic matter solubilisation and enhanced biodegradability via thermal pretreatment. The optimisation of the integrated thermal pretreatment-biomethanation process resulted in up to 1.6-fold increase in methane yield.

  4. Polar coralline algal CaCO3-production rates correspond to intensity and duration of the solar radiation

    NASA Astrophysics Data System (ADS)

    Teichert, S.; Freiwald, A.

    2014-02-01

    In this study we present a comparative quantification of CaCO3 production rates by rhodolith-forming coralline red algal communities situated in high polar latitudes and assess which environmental parameters control these production rates. The present rhodoliths act as ecosystem engineers, and their carbonate skeletons provide an important ecological niche to a variety of benthic organisms. The settings are distributed along the coasts of the Svalbard archipelago, being Floskjeret (78°18' N) in Isfjorden, Krossfjorden (79°08' N) at the eastern coast of Haakon VII Land, Mosselbukta (79°53' N) at the eastern coast of Mosselhalvøya, and Nordkappbukta (80°31' N) at the northern coast of Nordaustlandet. All sites feature Arctic climate and strong seasonality. The algal CaCO3 production rates were calculated from fuchsine-stained, presumably annual growth increments exhibited by the rhodoliths and range from 100.9 g (CaCO3) m-2 yr-1 at Nordkappbukta to 200.3 g (CaCO3) m-2 yr-1 at Floskjeret. The rates correlate to various environmental parameters with geographical latitude being the most significant (negative correlation, R2 = 0.95, p = 0.0070), followed by the duration of the polar night (negative correlation, R2 = 0.93, p = 0.0220), the duration of the sea ice cover (negative correlation, R2 = 0.87, p = 0.0657), and the annual mean temperature (positive correlation, R2 = 0.48, p = 0.0301). This points out sufficient light incidence to be the main control of the growth of the examined coralline red algal rhodolith communities, while temperature is less important. Thus, the ongoing global change with its rising temperatures will most likely result in impaired conditions for the algae, because the concomitant increased global runoff will decrease water transparency and hence light incidence at the four offshore sites. Regarding the aforementioned role of the rhodoliths as ecosystem engineers, the impact on the associated organisms will presumably also be negative.

  5. Algal Biofuels Fact Sheet

    SciTech Connect

    2009-10-27

    This fact sheet provides information on algal biofuels, which are generating considerable interest around the world. They may represent a sustainable pathway for helping to meet the U.S. biofuel production targets set by the Energy Independence and Security Act of 2007.

  6. Improved biomass productivity in algal biofilms through synergistic interactions between photon flux density and carbon dioxide concentration.

    PubMed

    Schnurr, Peter J; Molenda, Olivia; Edwards, Elizabeth; Espie, George S; Allen, D Grant

    2016-11-01

    Algal biofilms were grown to investigate the interaction effects of bulk medium CO2 concentration and photon flux density (PFD) on biomass productivities. When increasing the CO2 concentration from 0.04% to 2%, while maintaining a PFD of 100μmol/m(2)/s, biomass productivities increased from ∼0.5 to 2.0g/m(2)/d; however, the productivities plateaued when CO2 concentrations were incrementally increased above 2-12%. Statistical analysis demonstrates that there is a significant interaction between PFD and CO2 concentrations on biomass productivities. By simultaneously increasing PFD and CO2 concentrations, biomass productivities were significantly increased to 4.0 and 4.1g/m(2)/d in the experimental and modeled data, respectively. The second order model predicted increases in biomass productivities as both PFD and CO2 simultaneously increased yielding an optimum at 440μmol/m(2)/s and 7.1%; however, when conditions were extended to the highest end of their respective ranges, the conditions were detrimental to growth and productivities decreased.

  7. Extracellular ligninolytic enzymes production by Pleurotus eryngii on agroindustrial wastes.

    PubMed

    Akpinar, Merve; Urek, Raziye Ozturk

    2014-01-01

    Pleurotus eryngii (DC.) Gillet (MCC58) was investigated for its ligninolytic ability to produce laccase (Lac), manganese peroxidase (MnP), aryl alcohol oxidase (AAO), and lignin peroxidase (LiP) enzymes through solid-state fermentation using apricot and pomegranate agroindustrial wastes. The reducing sugar, protein, lignin, and cellulose levels in these were studied. Also, the production of these ligninolytic enzymes was researched over the growth of the microorganism throughout 20 days, and the reducing sugar, protein, and nitrogen levels were recorded during the stationary cultivation at 28 ± 0.5°C. The highest Lac activity was obtained as 1618.5 ± 25 U/L on day 12 of cultivation using apricot. The highest MnP activity was attained as 570.82 ± 15 U/L on day 17 in pomegranate culture and about the same as apricot culture. There were low LiP activities in both cultures. The maximum LiP value detected was 16.13 ± 0.8 U/L in apricot cultures. In addition, AAO activities in both cultures showed similar trends up to day 17 of cultivation, with the highest AAO activity determined as 105.99 ± 6.3 U/L on day 10 in apricot cultures. Decolorization of the azo dye methyl orange was also achieved with produced ligninolytic enzymes by P. eryngii using apricot and pomegranate wastes. PMID:24279903

  8. Hfq regulates antibacterial antibiotic biosynthesis and extracellular lytic-enzyme production in Lysobacter enzymogenes OH11

    PubMed Central

    Xu, Gaoge; Zhao, Yuxin; Du, Liangcheng; Qian, Guoliang; Liu, Fengquan

    2015-01-01

    Lysobacter enzymogenes is an important biocontrol agent with the ability to produce a variety of lytic enzymes and novel antibiotics. Little is known about their regulatory mechanisms. Understanding these will be helpful for improving biocontrol of crop diseases and potential medical application. In the present study, we generated an hfq (encoding a putative ribonucleic acid chaperone) deletion mutant, and then utilized a new genomic marker-free method to construct an hfq-complemented strain. We showed for the first time that Hfq played a pleiotropic role in regulating the antibacterial antibiotic biosynthesis and extracellular lytic enzyme activity in L. enzymogenes. Mutation of hfq significantly increased the yield of WAP-8294A2 (an antibacterial antibiotic) as well as the transcription of its key biosynthetic gene, waps1. However, inactivation of hfq almost abolished the extracellular chitinase activity and remarkably decreased the activity of both extracellular protease and cellulase in L. enzymogenes. We further showed that the regulation of hfq in extracellular chitinase production was in part through the impairment of the secretion of chitinase A. Collectively, our results reveal the regulatory roles of hfq in antibiotic metabolite and extracellular lytic enzymes in the underexplored genus of Lysobacter. PMID:25683974

  9. Measurement and Analysis of Extracellular Acid Production to Determine Glycolytic Rate.

    PubMed

    Mookerjee, Shona A; Brand, Martin D

    2015-12-12

    Extracellular measurement of oxygen consumption and acid production is a simple and powerful way to monitor rates of respiration and glycolysis(1). Both mitochondrial (respiration) and non-mitochondrial (other redox) reactions consume oxygen, but these reactions can be easily distinguished by chemical inhibition of mitochondrial respiration. However, while mitochondrial oxygen consumption is an unambiguous and direct measurement of respiration rate(2), the same is not true for extracellular acid production and its relationship to glycolytic rate (3-6). Extracellular acid produced by cells is derived from both lactate, produced by anaerobic glycolysis, and CO2, produced in the citric acid cycle during respiration. For glycolysis, the conversion of glucose to lactate(-) + H(+) and the export of products into the assay medium is the source of glycolytic acidification. For respiration, the export of CO2, hydration to H2CO3 and dissociation to HCO3(-) + H(+) is the source of respiratory acidification. The proportions of glycolytic and respiratory acidification depend on the experimental conditions, including cell type and substrate(s) provided, and can range from nearly 100% glycolytic acidification to nearly 100% respiratory acidification (6). Here, we demonstrate the data collection and calculation methods needed to determine respiratory and glycolytic contributions to total extracellular acidification by whole cells in culture using C2C12 myoblast cells as a model.

  10. The effects of alternative pretreatment strategies on anaerobic digestion and methane production from different algal strains.

    PubMed

    Bohutskyi, Pavlo; Betenbaugh, Michael J; Bouwer, Edward J

    2014-03-01

    The effect of various pretreatment strategies on methane yields following anaerobic digestion (AD) of five different microalgal strains was investigated. Pavlova_cf sp., Tetraselmis sp. and Thalassiosira weissflogii exhibited substantial methane yields of 0.4-0.5L/g volatile solids (VS) without pretreatment, providing up to 75-80% of theoretical values. In contrast, methane yields from Chlorella sp. and Nannochloropsis sp. were around 0.35L/g VS, or 55-60% of the theoretical values, respectively. Alkali treatment was not effective and thermal pretreatment only enhanced Nannochloropsis methane yields. Thermochemical pretreatment had the strongest impact on biomass solubilization with methane yields increasing by 30% and 40% for Chlorella and Nannochloropsis, respectively. The lipid content had a strong beneficial impact on the theoretical and observed methane yields as compared to protein and carbohydrate content. Other features such as cell-wall composition are also likely to be important factors dictating algal biodegradability and methane yields addressed in part by thermochemical pretreatment.

  11. Strategies for improving extracellular lipolytic enzyme production by Thermus thermophilus HB27.

    PubMed

    Deive, Francisco J; Carvalho, Elisabete; Pastrana, Lorenzo; Rúa, Maria L; Longo, Maria A; Sanroman, M Angeles

    2009-07-01

    In Thermus thermophilus HB27 cultures the localisation of lipolytic activity is extracellular, intracellular and membrane bound, with low percentage for the former. Therefore, the extracellular secretion must be increased in order to simplify the downstream process and to reduce the economic cost. This study focuses on the design of an innovative operational strategy to increase extracellular lipolytic enzyme production by T. thermophilus HB27 at bioreactor scale. In order to favour its secretion, the effect of several operational variables was evaluated. Among them, the presence of oils in the culture medium leads to improvements in growth and lipolytic enzyme activity. Sunflower oil is the most efficient inducer showing better results when added after 10h of growth. On the other hand, although surfactants lead to an almost complete inhibition of growth and lipolytic enzyme production, their addition along the culture could affect the location of the enzyme. Thus, by addition of surfactants at the stationary phase, a release of intracellular and membrane enzyme which increases the extracellular enzyme proportion is detected. Based on these results, strategies with successive addition of oil and surfactant in several culture phases in shake flask are developed and verified in a laboratory scale stirred tank bioreactor.

  12. Application of low-cost algal nitrogen source feeding in fuel ethanol production using high gravity sweet potato medium.

    PubMed

    Shen, Yu; Guo, Jin-Song; Chen, You-Peng; Zhang, Hai-Dong; Zheng, Xu-Xu; Zhang, Xian-Ming; Bai, Feng-Wu

    2012-08-31

    Protein-rich bloom algae biomass was employed as nitrogen source in fuel ethanol fermentation using high gravity sweet potato medium containing 210.0 g l(-1) glucose. In batch mode, the fermentation could not accomplish even in 120 h without any feeding of nitrogen source. While, the feeding of acid-hydrolyzed bloom algae powder (AHBAP) notably promoted fermentation process but untreated bloom algae powder (UBAP) was less effective than AHBAP. The fermentation times were reduced to 96, 72, and 72 h if 5.0, 10.0, and 20.0 g l(-1) AHBAP were added into medium, respectively, and the ethanol yields and productivities increased with increasing amount of feeding AHBAP. The continuous fermentations were performed in a three-stage reactor system. Final concentrations of ethanol up to 103.2 and 104.3 g l(-1) with 4.4 and 5.3 g l(-1) residual glucose were obtained using the previously mentioned medium feeding with 20.0 and 30.0 g l(-1) AHBAP, at dilution rate of 0.02 h(-1). Notably, only 78.5 g l(-1) ethanol and 41.6 g l(-1) residual glucose were obtained in the comparative test without any nitrogen source feeding. Amino acids analysis showed that approximately 67% of the protein in the algal biomass was hydrolyzed and released into the medium, serving as the available nitrogen nutrition for yeast growth and metabolism. Both batch and continuous fermentations showed similar fermentation parameters when 20.0 and 30.0 g l(-1) AHBAP were fed, indicating that the level of available nitrogen in the medium should be limited, and an algal nitrogen source feeding amount higher than 20.0 g l(-1) did not further improve the fermentation performance.

  13. Importance of Vascular Plant and Algal Production to Macro-invertebrate Consumers in a Southern California Salt Marsh

    NASA Astrophysics Data System (ADS)

    Page, H. M.

    1997-12-01

    The dietary importance of marsh vascular plants (primarilySalicornia virginica), algae and upland particulate inputs to macro-invertebrate consumers was studied in Carpinteria Salt Marsh, southern California, using stable carbon and nitrogen isotope ratios. This marsh is predominantly a marine or hypersaline system and succulents are the most common vascular plant species. Of invertebrates collected from the vegetated marsh, tidal flats and channels, only detritivores from the vegetated marsh (Traskorchestia traskiana,Melampus olivaceus) had isotope values (δ13C=-20‰) that suggested some use ofSalicornia-derived carbon.T. traskianacultured in the laboratory on decomposingS. virginicaor blue-green micro-algal mat had distinctive isotopic signatures, reflecting the capability of this consumer to assimilate carbon and nitrogen derived from these sources. The δ13C values (generally -16‰ to -15‰) of species from tidal flats and channels (e.g.Cerithidea californica,Protothaca staminea,Mytilus galloprovincialis,Neotrypaea californiensis) were most similar to values for benthic algae and phytoplankton. Specimens ofM. galloprovincialisalong a gradient of presumed increase in marine influence had similar isotope values, suggesting little contribution to diet from upland runoff. The present results differ most noticeably from published values in the13C enrichment of suspension-feeders, suggesting the use of resuspended13C-enriched benthic microalgae in tidal channels by these consumers, and in the13C depletion and15N enrichment of plants and consumers along a portion of the marsh boundary receiving inputs of nutrient-enriched perched groundwater. In general, the isotopic composition of macro-invertebrates indicated the incorporation of algal production rather than ofS. virginicaor upland sources into the marsh food web.

  14. Extracellular peptidase hunting for improvement of protein production in plant cells and roots.

    PubMed

    Lallemand, Jérôme; Bouché, Frédéric; Desiron, Carole; Stautemas, Jennifer; de Lemos Esteves, Frédéric; Périlleux, Claire; Tocquin, Pierre

    2015-01-01

    Plant-based recombinant protein production systems have gained an extensive interest over the past few years, because of their reduced cost and relative safety. Although the first products are now reaching the market, progress are still needed to improve plant hosts and strategies for biopharming. Targeting recombinant proteins toward the extracellular space offers several advantages in terms of protein folding and purification, but degradation events are observed, due to endogenous peptidases. This paper focuses on the analysis of extracellular proteolytic activities in two production systems: cell cultures and root-secretion (rhizosecretion), in Arabidopsis thaliana and Nicotiana tabacum. Proteolytic activities of extracellular proteomes (secretomes) were evaluated in vitro against two substrate proteins: bovine serum albumin (BSA) and human serum immunoglobulins G (hIgGs). Both targets were found to be degraded by the secretomes, BSA being more prone to proteolysis than hIgGs. The analysis of the proteolysis pH-dependence showed that target degradation was mainly dependent upon the production system: rhizosecretomes contained more peptidase activity than extracellular medium of cell suspensions, whereas variations due to plant species were smaller. Using class-specific peptidase inhibitors, serine, and metallopeptidases were found to be responsible for degradation of both substrates. An in-depth in silico analysis of genomic and transcriptomic data from Arabidopsis was then performed and led to the identification of a limited number of serine and metallo-peptidases that are consistently expressed in both production systems. These peptidases should be prime candidates for further improvement of plant hosts by targeted silencing.

  15. Extracellular peptidase hunting for improvement of protein production in plant cells and roots.

    PubMed

    Lallemand, Jérôme; Bouché, Frédéric; Desiron, Carole; Stautemas, Jennifer; de Lemos Esteves, Frédéric; Périlleux, Claire; Tocquin, Pierre

    2015-01-01

    Plant-based recombinant protein production systems have gained an extensive interest over the past few years, because of their reduced cost and relative safety. Although the first products are now reaching the market, progress are still needed to improve plant hosts and strategies for biopharming. Targeting recombinant proteins toward the extracellular space offers several advantages in terms of protein folding and purification, but degradation events are observed, due to endogenous peptidases. This paper focuses on the analysis of extracellular proteolytic activities in two production systems: cell cultures and root-secretion (rhizosecretion), in Arabidopsis thaliana and Nicotiana tabacum. Proteolytic activities of extracellular proteomes (secretomes) were evaluated in vitro against two substrate proteins: bovine serum albumin (BSA) and human serum immunoglobulins G (hIgGs). Both targets were found to be degraded by the secretomes, BSA being more prone to proteolysis than hIgGs. The analysis of the proteolysis pH-dependence showed that target degradation was mainly dependent upon the production system: rhizosecretomes contained more peptidase activity than extracellular medium of cell suspensions, whereas variations due to plant species were smaller. Using class-specific peptidase inhibitors, serine, and metallopeptidases were found to be responsible for degradation of both substrates. An in-depth in silico analysis of genomic and transcriptomic data from Arabidopsis was then performed and led to the identification of a limited number of serine and metallo-peptidases that are consistently expressed in both production systems. These peptidases should be prime candidates for further improvement of plant hosts by targeted silencing. PMID:25705212

  16. Effects of cyanobacterial extracellular products and gibberellic acid on salinity tolerance in Oryza sativa L

    PubMed Central

    Rodríguez, AA; Stella, AM; Storni, MM; Zulpa, G; Zaccaro, MC

    2006-01-01

    Salt stress is one of the most serious factors limiting the productivity of rice, the staple diet in many countries. Gibberellic acid has been reported to reduce NaCl-induced growth inhibition in some plants including rice. Most paddy soils have a natural population of Cyanobacteria, prokaryotic photosynthethic microorganisms, which synthesize and liberate plant growth regulators such as gibberellins that could exert a natural beneficial effect on salt stressed rice plants. The aim of this work was to evaluate the effect of the cyanobacterium Scytonema hofmanni extracellular products on the growth of rice seedlings inhibited by NaCl and to compare it with the effect of the gibberellic acid in the same stress condition. Growth (length and weight of the seedlings) and biochemical parameters (5-aminolevulinate dehydratase activity, total free porphyrin and pigments content) were evaluated. Salt exposure negatively affected all parameters measured, with the exception of chlorophyll. Chlrorophyll concentrations nearly doubled upon exposure to high salt. Gibberellic acid counteracted the effect of salt on the length and dry weight of the shoot, and on carotenoid and chlorophyll b contents. Extracellular products nullified the salt effect on shoot dry weight and carotenoid content; partially counteracted the effect on shoot length (from 54% to 38% decrease), root dry weight (from 59% to 41% decrease) and total free porphyrin (from 31 to 13% decrease); reduced by 35% the salt increase of chlorophyll a; had no effect on root length and chlorophyll b. Gibberellic acid and extracellular products increased 5-aminolevulinate dehydratase activity over the control without salt. When coincident with high salinity, exposure to either EP or GA3, resulted in a reversal of shoot-related responses to salt stress. We propose that Scytonema hofmanni extracellular products may counteract altered hormone homeostasis of rice seedlings under salt stress by producing gibberellin-like plant

  17. Extracellular peptidase hunting for improvement of protein production in plant cells and roots

    PubMed Central

    Lallemand, Jérôme; Bouché, Frédéric; Desiron, Carole; Stautemas, Jennifer; de Lemos Esteves, Frédéric; Périlleux, Claire; Tocquin, Pierre

    2015-01-01

    Plant-based recombinant protein production systems have gained an extensive interest over the past few years, because of their reduced cost and relative safety. Although the first products are now reaching the market, progress are still needed to improve plant hosts and strategies for biopharming. Targeting recombinant proteins toward the extracellular space offers several advantages in terms of protein folding and purification, but degradation events are observed, due to endogenous peptidases. This paper focuses on the analysis of extracellular proteolytic activities in two production systems: cell cultures and root-secretion (rhizosecretion), in Arabidopsis thaliana and Nicotiana tabacum. Proteolytic activities of extracellular proteomes (secretomes) were evaluated in vitro against two substrate proteins: bovine serum albumin (BSA) and human serum immunoglobulins G (hIgGs). Both targets were found to be degraded by the secretomes, BSA being more prone to proteolysis than hIgGs. The analysis of the proteolysis pH-dependence showed that target degradation was mainly dependent upon the production system: rhizosecretomes contained more peptidase activity than extracellular medium of cell suspensions, whereas variations due to plant species were smaller. Using class-specific peptidase inhibitors, serine, and metallopeptidases were found to be responsible for degradation of both substrates. An in-depth in silico analysis of genomic and transcriptomic data from Arabidopsis was then performed and led to the identification of a limited number of serine and metallo-peptidases that are consistently expressed in both production systems. These peptidases should be prime candidates for further improvement of plant hosts by targeted silencing. PMID:25705212

  18. Seasonal and interannual variability in algal biomass and primary production in the Mediterranean Sea, as derived from 4 years of SeaWiFS observations

    NASA Astrophysics Data System (ADS)

    Bosc, E.; Bricaud, A.; Antoine, D.

    2004-03-01

    Because the Mediterranean has been subject for several decades to increasing anthropogenic influences, monitoring algal biomass and primary production on a long-term basis is required to detect possible modifications in the biogeochemical equilibrium of the basin. This work was initiated thanks to a 4-year-long time series of SeaWiFS observations. Seasonal variations of algal biomass (estimated using a previously developed regional algorithm) and primary production were analyzed for the various regions, and compared with those estimated using the CZCS sensor (1978-1986). Also, interannual variations could be assessed for the first time. The seasonal cycles of algal biomass generally reveal a maximum in winter or spring, and a minimum in summer. Some conspicuous differences with CZCS observations (e.g., in the Northwest Basin, reduction of the deep convection zone, earlier start of the spring bloom, quasi-absence of the vernal bloom) likely result from environmental changes. Interannual variations in algal biomass are noticeable all over the basin, including in the very oligotrophic waters of the Eastern Basin. The seasonal evolution of primary production is predominantly influenced by that of algal biomass in the Western Basin (with, in particular, a spring maximum). In the Eastern Basin, the seasonal courses of PAR and biomass tend to compensate each other, and primary production varies weakly along the year. The annual values computed over the 1998-2001 period for the Western Basin (163 ± 7 gC m-2 yr-1) and the Eastern Basin (121 ± 5 gC m-2 yr-1) are lower (by 17 and 12%, respectively) than those previously derived (using the same light-photosynthesis model) from CZCS data.

  19. Algal Lipids and Omega-3 Production via Autotrophic and Heterotrophic Pathways at Cellana?s Kona Demonstration Facility, Hawaii

    SciTech Connect

    Bai, Xuemei; Knurek, Emily; Goes, Nikki; Griswold, Lynn

    2012-05-05

    Cellana?s Kona Demonstration Facility (KDF) is a 2.5 hectare facility, with 17,000 sq. ft. under roof and 1 hectare of cultivation systems. KDF is designed to execute and support all stages of the production process at pilot scale, from cultivation through extraction. Since Feb. 2009, KDF has been producing up to 0.7MT dry weight of algal biomass per month, while at the same time optimizing processes of cultivation, harvesting, dewatering and extraction. The cultivation system at KDF uses ALDUO? technology, a hybrid system of photobioreactors (PBRs) and open ponds. All fluid transfers related to KDF cultivation and harvesting processes are operated and monitored by a remote Process-Control System. Fluid transfer data, together with biochemical data, enable the mass balance calculations necessary to measure productivity. This poster summarizes methods to improve both biomass and lipids yield by 1) alleviating light limitation in open ponds, 2) de-oxygenation and 3) heterotrophic lipid production for post-harvesting cultures.

  20. Phenazine production enhances extracellular DNA release via hydrogen peroxide generation in Pseudomonas aeruginosa

    PubMed Central

    Das, Theerthankar; Manefield, Mike

    2013-01-01

    In Pseudomonas aeruginosa eDNA is a crucial component essential for biofilm formation and stability. In this study we report that release of eDNA is influenced by the production of phenazine in P. aeruginosa. A ∆phzA-G mutant of P. aeruginosa PA14 deficient in phenazine production generated significantly less eDNA in comparison with the phenazine producing strains. The relationship between eDNA release and phenazine production is bridged via hydrogen peroxide (H2O2) generation and subsequent H2O2 mediated cell lysis and ultimately release of chromosomal DNA into the extracellular environment as eDNA. PMID:23710274

  1. Algal Nitrate Assimilation and Productivity in an Urban, Concrete-Lined Stream Dominated by Tertiary Treated Municipal Waste-Water

    NASA Astrophysics Data System (ADS)

    Kent, R. H.; Burton, C. A.

    2001-12-01

    This study examined the extent and variabiltity of nitrate loss in a 2.85 km reach of Cucamonga Creek, which is concrete-lined and dominated by treated municipal waste-water. Primary production was measured to determine if the loss could be attributed to algal assimilation. Samples for nitrite plus nitrate analysis were collected at the top and bottom of the study reach every hour throughout the 24-hour sampling period; samples for analyses of other parameters were collected less frequently. Water temperature, dissolved oxygen (DO), pH and specific conductance were monitored continuously throughout the sampling period using in-stream probes. During the two weeks prior to the study, periphyton samples were collected periodically at four stations along the reach for standing crop measurements and a growth rate time-series using Chlorophyll A and ash-free-dry mass. Water samples from the upstream station were compared to those taken an hour later (the approximate travel time) at the downstream station. Nitrate concentrations were lower at the downstream station in 21 of 25 of the paired samples, indicating nearly continuous loss in the reach. The total loss of NO3 for the day was about 0.71 g as N/m2. Most of the loss occurred during daylight hours, with the peak occurring at midday. During the night, CO2 concentrations were relatively constant at about 25 mg/L. Concentrations began to decline at sunrise, and declined to 0 mg/L at the lower site after midday. Peak nitrate loss occurred at about the same time as the CO2 concentration was at its minimum. DO declined slightly during the night, began to rise at sunrise, reached a peak during midday, and declined in late afternoon through evening; pH followed a similar pattern. Net primary productivity, as measured by the differences in DO between the two sites was 13 g O2/m2 for the day. Using the Redfield ratio, the predicted nitrate assimilation is about 0.66 g NO3 as N/m2. The continuous loss of nitrate between the two

  2. Mutations affecting extracellular protease production in the filamentous fungus Aspergillus nidulans.

    PubMed

    Katz, M E; Flynn, P K; vanKuyk, P A; Cheetham, B F

    1996-04-10

    The extracellular proteases of Aspergillus nidulans are known to be regulated by carbon, nitrogen and sulphur metabolite repression. In this study, a mutant with reduced levels of extracellular protease was isolated by screening for loss of halo production on milk plates. Genetic analysis of the mutant showed that it contains a single, recessive mutation, in a gene which we have designated xprE, located on chromosome VI. The xprE1 mutation affected the production of extracellular proteases in response to carbon, nitrogen and, to a lesser extent, sulphur limitation. Three reversion mutations, xprF1, xprF2 and xprG1, which suppress xprE1, were characterised. Both xprF and xprG map to chromosome VII but the two genes are unlinked. The xprF1, xprF2 and xprG1 mutants showed high levels of milk-clearing activity on medium containing milk as a carbon source but reduced growth on a number of nitrogen sources. Evidence is presented that the xprE1 and xprG1 mutations alter expression of more than one protease and affect levels of alkaline protease gene mRNA.

  3. Mechanism of interferon-gamma production by monocytes stimulated with myeloperoxidase and neutrophil extracellular traps.

    PubMed

    Yamaguchi, Rui; Kawata, Jin; Yamamoto, Toshitaka; Ishimaru, Yasuji; Sakamoto, Arisa; Ono, Tomomichi; Narahara, Shinji; Sugiuchi, Hiroyuki; Hirose, Eiji; Yamaguchi, Yasuo

    2015-08-01

    Neutrophil extracellular traps (NETs) have an important role in antimicrobial innate immunity and release substances that may modulate the immune response. We investigated the effects of soluble factors from NETs and neutrophil granule proteins on human monocyte function by using the Transwell system to prevent cell-cell contact. NET formation was induced by exposing human neutrophils to phorbol myristate acetate (PMA). When monocytes were incubated with PMA alone, expression of interleukin (IL)-4, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha mRNA was upregulated, but IL-10, IL-12, and interferon (IFN)-gamma mRNA were not detected. Incubation of monocytes with NETs enhanced the expression of IL-10 and IFN-gamma mRNA, but not IL-12 mRNA. Myeloperoxidase stimulated IFN-gamma production by monocytes in a dose-dependent manner. Both a nuclear factor-kappaB inhibitor (PDTC) and an intracellular calcium antagonist (TMB-8) prevented upregulation of IFN-gamma production. Neither a combined p38alpha and p38beta inhibitor (SB203580) nor an extracellular signal-regulated kinase inhibitor (PD98059) suppressed IFN-gamma production. Interestingly, a combined p38gamma and p38delta inhibitor (BIRB796) significantly decreased IFN-gamma production. These findings suggest that myeloperoxidase induces IFN-gamma production by monocytes via p38gamma/delta mitogen-activated protein kinase.

  4. Inexpensive non-toxic flocculation of microalgae contradicts theories; overcoming a major hurdle to bulk algal production.

    PubMed

    Schlesinger, Ami; Eisenstadt, Doron; Bar-Gil, Amicam; Carmely, Hilla; Einbinder, Shai; Gressel, Jonathan

    2012-01-01

    There are two major energy and cost constraints to bulk production of single cell microalgae for biofuels or feed: expensive culture systems with high capital costs and high energy requirements for mixing and gas exchange; and the cost of harvesting using high-speed continuous centrifugation for dewatering. This report deals with the latter; harvesting by flocculation where theory states that alkaline flocculants neutralize the repelling surface charge of algal cells, allowing them to coalesce into a floc. It had been assumed that with such electrostatic flocculation, the more cells to be flocculated, the more flocculant needed, in a linear stoichiometric fashion, rendering flocculation overly expensive. Counter to theory of electrostatic flocculation, we find that the amount of alkaline flocculant needed is a function of the logarithm of cell density, with dense cultures requiring an order of magnitude less base than dilute suspensions, with flocculation occurring at a lower pH. Various other theories abound that flocculation can be due to multi-valent cross-linking, or co-precipitation with phosphate or with magnesium and calcium, but are clearly not relevant with the flocculants we used. Monovalent bases that cannot cross-link or precipitate phosphate work with the same log-linear stoichiometry as the divalent bases, obviating those theories, leaving electrostatic flocculation as the only tenable theory of flocculation with the materials used. The cost of flocculation of dense cultures with this procedure should be below $1.00/T algae for mixed calcium:magnesium hydroxides.

  5. Harmful algal blooms (HABs) in Daya Bay, China: an in situ study of primary production and environmental impacts.

    PubMed

    Song, Xingyu; Huang, Liangmin; Zhang, Jianlin; Huang, Honghui; Li, Tao; Su, Qiang

    2009-09-01

    A month-long investigation of phytoplankton biomass and primary production (PP) was carried out during a harmful algal bloom (HAB) in Daya Bay, China, in 2003. During the bloom, the phytoplankton community was dominated by Scrippsiella trochoidea and Chattonella marina. The phytoplankton biomass (Chl a) and PP reached peak levels of 519.21mgm(-3) and 734.0mgCm(-3)h(-1), respectively. Micro-phytoplankton was the key contributor to Chl a and PP in a cage-culture area and in the adjacent HAB-affected waters, with percentages of up to 82.91% and 84.94%, respectively. The HAB had complicated relationships with hydrological and meteorological factors in Daya Bay. However, the water around the cage-culture area always showed statistically greater phytoplankton biomass and nutrient loadings than in adjacent waters, suggesting that this was the "trigger area" of the bloom. The spatial and temporal distribution of diverse HABs in Daya Bay, their ecological characteristics, and their environmental impacts are also discussed in this paper.

  6. Impact of Interdecadal Sea Level and Sea Surface Temperature Variability on Primary Productivity and Harmful Algal Blooms in Southern California

    NASA Astrophysics Data System (ADS)

    Perry, K. L.

    2014-12-01

    Harmful Algal Blooms (HABs) are increasing in frequency and intensity on global, regional and local scales. Although climate change has been suggested as one of the key factors, very few interdecadal studies comparing HABs to low frequency physical forcing have been performed. Interannual to interdecadal variability in sea level and sea surface temperature along the Southern California Coast have been shown to have high correlation with the El Nino-La Nina signal. This is important in the study of phytoplankton, because abnormally low sea level corresponds to increased sea surface nutrient concentrations in this region. The California current is stronger during these times, and the higher nutrient water found to the north is advected southward. We have determined that primary productivity is most highly correlated with interdecadal sea level variability derived from tide gage data at a lag of approximately 2 months. This is consistent with previous zooplankton studies. In preparation for a potential El Nino event, we have expanded our analysis to include parameters such as sea surface temperature, salinity and nutrient concentrations from spaceborne and in situ instruments. We have also expanded our research to allow for analysis of several of the most prevalent HAB species. This work is the first step in our effort to create a model to predict and locate Southern California HAB events in the future.

  7. Algal culture studies for CELSS

    NASA Technical Reports Server (NTRS)

    Radmer, R.; Behrens, P.; Arnett, K.; Gladue, R.; Cox, J.; Lieberman, D.

    1987-01-01

    Microalgae are well-suited as a component of a Closed Environmental Life Support System (CELSS), since they can couple the closely related functions of food production and atmospheric regeneration. The objective was to provide a basis for predicting the response of CELSS algal cultures, and thus the food supply and air regeneration system, to changes in the culture parameters. Scenedesmus growth was measured as a function of light intensity, and the spectral dependence of light absorption by the algae as well as algal respiration in the light were determined as a function of cell concentration. These results were used to test and confirm a mathematical model that describes the productivity of an algal culture in terms of the competing processes of photosynthesis and respiration. The relationship of algal productivity to cell concentration was determined at different carbon dioxide concentrations, temperatures, and light intensities. The maximum productivity achieved by an air-grown culture was found to be within 10% of the computed maximum productivity, indicating that CO2 was very efficiently removed from the gas stream by the algal culture. Measurements of biomass productivity as a function of cell concentration at different light intensities indicated that both the productivity and efficiency of light utilization were greater at higher light intensities.

  8. Inhibitors of Serine Proteases in Regulating the Production and Function of Neutrophil Extracellular Traps

    PubMed Central

    Majewski, Pawel; Majchrzak-Gorecka, Monika; Grygier, Beata; Skrzeczynska-Moncznik, Joanna; Osiecka, Oktawia; Cichy, Joanna

    2016-01-01

    Neutrophil extracellular traps (NETs), DNA webs released into the extracellular environment by activated neutrophils, are thought to play a key role in the entrapment and eradication of microbes. However, NETs are highly cytotoxic and a likely source of autoantigens, suggesting that NET release is tightly regulated. NET formation involves the activity of neutrophil elastase (NE), which cleaves histones, leading to chromatin decondensation. We and others have recently demonstrated that inhibitors of NE, such as secretory leukocyte protease inhibitor (SLPI) and SerpinB1, restrict NET production in vitro and in vivo. SLPI was also identified as a NET component in the lesional skin of patients suffering from the autoinflammatory skin disease psoriasis. SLPI-competent NET-like structures (a mixture of SLPI with neutrophil DNA and NE) stimulated the synthesis of interferon type I (IFNI) in plasmacytoid dendritic cells (pDCs) in vitro. pDCs uniquely respond to viral or microbial DNA/RNA but also to nucleic acids of “self” origin with the production of IFNI. Although IFNIs are critical in activating the antiviral/antimicrobial functions of many cells, IFNIs also play a role in inducing autoimmunity. Thus, NETs decorated by SLPI may regulate skin immunity through enhancing IFNI production in pDCs. Here, we review key aspects of how SLPI and SerpinB1 can control NET production and immunogenic function. PMID:27446090

  9. Extracellular matrix production and calcium carbonate precipitation by coral cells in vitro.

    PubMed

    Helman, Yael; Natale, Frank; Sherrell, Robert M; Lavigne, Michèle; Starovoytov, Valentin; Gorbunov, Maxim Y; Falkowski, Paul G

    2008-01-01

    The evolution of multicellularity in animals required the production of extracellular matrices that serve to spatially organize cells according to function. In corals, three matrices are involved in spatial organization: (i) an organic ECM, which facilitates cell-cell and cell-substrate adhesion; (ii) a skeletal organic matrix (SOM), which facilitates controlled deposition of a calcium carbonate skeleton; and (iii) the calcium carbonate skeleton itself, which provides the structural support for the 3D organization of coral colonies. In this report, we examine the production of these three matrices by using an in vitro culturing system for coral cells. In this system, which significantly facilitates studies of coral cell physiology, we demonstrate in vitro excretion of ECM by primary (nondividing) tissue cultures of both soft (Xenia elongata) and hard (Montipora digitata) corals. There are structural differences between the ECM produced by X. elongata cell cultures and that of M. digitata, and ascorbic acid, a critical cofactor for proline hydroxylation, significantly increased the production of collagen in the ECM of the latter species. We further demonstrate in vitro production of SOM and extracellular mineralized particles in cell cultures of M. digitata. Inductively coupled plasma mass spectrometry analysis of Sr/Ca ratios revealed the particles to be aragonite. De novo calcification was confirmed by following the incorporation of (45)Ca into acid labile macromolecules. Our results demonstrate the ability of isolated, differentiated coral cells to undergo fundamental processes required for multicellular organization. PMID:18162537

  10. Luminescent photobioreactor design for improved algal growth and photosynthetic pigment production through spectral conversion of light.

    PubMed

    Mohsenpour, Seyedeh Fatemeh; Willoughby, Nik

    2013-08-01

    Growth characteristics of two strains of microalgae in bubble column photobioreactors were investigated under different cultivation conditions. Chlorella vulgaris and Gloeothece membranacea were cultivated in luminescent acrylic photobioreactors at different seed culture densities. Luminescent acrylic photobioreactors in blue, green, yellow, orange, and red colours capable of spectral conversion of light were used. The results indicated that the red luminescent photobioreactor enhanced biomass production in both strains of microalgae while pigmentation was induced under different light colours. Green light promoted chlorophyll production in C. vulgaris however chlorophyll production in G. membranacea cultures was less influenced by the light condition or culture density. Phycobiliproteins were the dominant pigments in G. membranacea and red light favoured synthesis of these pigments.

  11. Fueling Future with Algal Genomics

    SciTech Connect

    Grigoriev, Igor

    2012-07-05

    Algae constitute a major component of fundamental eukaryotic diversity, play profound roles in the carbon cycle, and are prominent candidates for biofuel production. The US Department of Energy Joint Genome Institute (JGI) is leading the world in algal genome sequencing (http://jgi.doe.gov/Algae) and contributes of the algal genome projects worldwide (GOLD database, 2012). The sequenced algal genomes offer catalogs of genes, networks, and pathways. The sequenced first of its kind genomes of a haptophyte E.huxleyii, chlorarachniophyte B.natans, and cryptophyte G.theta fill the gaps in the eukaryotic tree of life and carry unique genes and pathways as well as molecular fossils of secondary endosymbiosis. Natural adaptation to conditions critical for industrial production is encoded in algal genomes, for example, growth of A.anophagefferens at very high cell densities during the harmful algae blooms or a global distribution across diverse environments of E.huxleyii, able to live on sparse nutrients due to its expanded pan-genome. Communications and signaling pathways can be derived from simple symbiotic systems like lichens or complex marine algae metagenomes. Collectively these datasets derived from algal genomics contribute to building a comprehensive parts list essential for algal biofuel development.

  12. Impact of pre-ozonation on disinfection by-product formation and speciation from chlor(am)ination of algal organic matter of Microcystis aeruginosa.

    PubMed

    Zhu, Mingqiu; Gao, Naiyun; Chu, Wenhai; Zhou, Shiqing; Zhang, Zhengde; Xu, Yaqun; Dai, Qi

    2015-10-01

    The increasing use of algal-impacted source waters is increasing concerns over exposure to disinfection byproducts (DBPs) in drinking water disinfection, due to the higher concentrations of DBP precursors in these waters. The impact of pre-ozonation on the formation and speciation of DBPs during subsequent chlorination and chloramination of algal organic matter (AOM), including extracellular organic matter (EOM) and intracellular organic matter (IOM), was investigated. During subsequent chlorination, ozonation pretreatment reduced the formation of haloacetonitriles from EOM, but increased the yields of trihalomethanes, dihaloacetic acid and trichloronitromethane from both EOM and IOM. While in chloramination, pre-ozonation remarkably enhanced the yields of several carbonaceous DBPs from IOM, and significantly minimized the nitrogenous DBP precursors. Also, the yield of 1,1-dichloro-2-propanone from IOM was decreased by 24.0% after pre-ozonation during chloramination. Both increases and decreases in the bromine substitution factors (BSF) of AOM were observed with ozone pretreatment at the low bromide level (50μg/L). However, pre-ozonation played little impact on the bromide substitution in DBPs at the high bromide level (500μg/L). This information was used to guide the design and practical operation of pre-ozonation in drinking water treatment plants using algae-rich waters.

  13. Extracellular enzyme production by Rhizopus and Mucor species on solid media.

    PubMed

    Thompson, D P; Eribo, B E

    1984-01-01

    Solid media were employed to determine the presence and absence of extracellular enzyme production by two genera of fruit-rot fungi, Rhizopus and Mucor. The results of this investigation revealed that phosphatase was released into the cultural medium by all the fungi examined; however, only R. oryzae, R. tritici, M. mucedo, and M. piriformis showed the possibility of being high producers of the enzyme. Protease, urease, ribonuclease, pectate lyase, and polygalacturonase, at varying levels of activity, were detected, in the majority of the fungi, in the cultural medium.

  14. Extracellular production of a sphingomyelinase from Streptomyces griseocarneus using Streptomyces lividans.

    PubMed

    Sugimori, Daisuke; Tomita, Yu; Matsumoto, Yusaku; Ogino, Chiaki

    2011-04-01

    The structural gene for sphingomyelinase (SMase) from Streptomyces griseocarneus, was introduced into Streptomyces lividans using a shuttle vector, pUC702, for Escherichia coli/S. lividans. High-level secretory production of SMase was achieved using the promoter, signal sequence and terminator regions of phospholipase D from Streptoverticillium cinnamoneum. The transformant constitutively expressed a high specific activity of SMase extracellularly during batch culture. Maximum SMase activity (555 ± 114 U/mg protein) was with 1.75 M MgCl(2) which was about 50-fold more than that with 10 mM MgCl(2).

  15. Production and composition of extracellular polysaccharide synthesized by a Rhizobium isolate of Vigna mungo (L.) Hepper.

    PubMed

    Mandal, Santi Mohan; Ray, Bimalendu; Dey, Satyahari; Pati, Bikas Ranjan

    2007-08-01

    An extracellular polysaccharide (EPS) was produced by a Rhizobium sp. isolated from the root nodules of Vigna mungo (L.) Hepper. Maximum EPS production (346 mg l(-1)) was when the yeast extract basal medium was supplemented with mannitol (1%), biotin (1.5 mg l(-1)) and asparagine (0.3%). Ribose (53%) and mannose (47%) were the principle monomers of the EPS. Chemical, chromatographic and spectroscopic analysis showed that this polymer, which has Man(4)Rib(1) as an oligomeric subunit, has an apparent molecular mass of 750 kDa.

  16. Extracellular xylanase production by Pleurotus species on lignocellulosic wastes under in vivo condition using novel pretreatment.

    PubMed

    Singh, M P; Pandey, A K; Vishwakarma, S K; Srivastava, A K; Pandey, V K

    2012-01-01

    The production of extracellular xylanase by three species of Pleurotus species i.e. P. florida, P. flabellatus and P. sajor caju was studied under in vivo condition during their cultivation on pretreated lignocellulosic wastes. Neem (Azadirachta indica) oil and ashoka (Saraca indica) leaves extract were used for pretreatment of paddy straw and wheat straw. Between these two wastes, paddy straw pretreated with neem oil, supported better xylanase production than wheat straw. Initially, xylanase production was low but it increased in subsequent days and reached at peak on 25th day of cultivation of Pleurotus species. Thereafter, there was decrease in the activity of the enzyme. On 25th day of incubation P. florida produced maximum xylanase on neem oil pretreated paddy straw i.e. 10.59 Uh—1ml—1. Among the three species, P. florida showed maximum enzyme activity followed by P. flabellatus and P. sajor caju. PMID:23273208

  17. Enhancement of sludge reduction and methane production by removing extracellular polymeric substances from waste activated sludge.

    PubMed

    Nguyen, Minh Tuan; Mohd Yasin, Nazlina Haiza; Miyazaki, Toshiki; Maeda, Toshinari

    2014-12-01

    The management of waste activated sludge (WAS) recycling is a concern that affects the development of the future low-carbon society, particularly sludge reduction and biomass utilization. In this study, we investigated the effect of removing extracellular polymeric substances (EPS), which play important roles in the adhesion and flocculation of WAS, on increased sludge disintegration, thereby enhancing sludge reduction and methane production by anaerobic digestion. EPS removal from WAS by ethylenediaminetetraacetic acid (EDTA) significantly enhanced sludge reduction, i.e., 49 ± 5% compared with 27 ± 1% of the control at the end the digestion process. Methane production was also improved in WAS without EPS by 8881 ± 109 CH4 μmol g(-1) dry-weight of sludge. Microbial activity was determined by denaturing gradient gel electrophoresis and real-time polymerase chain reaction, which showed that the hydrolysis and acetogenesis stages were enhanced by pretreatment with 2% EDTA, with a larger methanogenic community and better methane production.

  18. Acid precipitation effects on algal productivity and biomass in Adirondack Mountain lakes

    SciTech Connect

    Hendrey, G.R.

    1982-12-01

    Relationships between phytoplankton communities and lake acidity in three Adirondack Mountain lakes were studied at Woods Lake (pH ca. 4.9), Sagamore Lake (pH ca. 5.5), and Panther Lake (pH ca. 7.0). Species numbers decrease with increasing acidity. Patterns of increasing biomass and productivity in Woods Lake may be atypical of similar oligotrophic lakes in that they develop rather slowly to maxima six weeks after ice-out, instead of occurring very close to ice-out. Contributions of netplankton, nannoplankton and ultraplankton to productivity per m/sup 2/ show that the smaller plankton are relatively more important in the more acid lakes. This pattern could be determined by nutrient availability (lake acidification is suspected of leading to decreased availability of phosphorus). This was consistent with a hypothesis that microbial heterotrophic activity is reduced with increasing acidity, but the smaller phytoplankton may be more leaky at low pH. 11 references, 2 tables.

  19. Ethanol production from marine algal hydrolysates using Escherichia coli KO11.

    PubMed

    Kim, Nag-Jong; Li, Hui; Jung, Kwonsu; Chang, Ho Nam; Lee, Pyung Cheon

    2011-08-01

    Algae biomass is a potential raw material for the production of biofuels and other chemicals. In this study, biomass of the marine algae, Ulva lactuca, Gelidium amansii,Laminaria japonica, and Sargassum fulvellum, was treated with acid and commercially available hydrolytic enzymes. The hydrolysates contained glucose, mannose, galactose, and mannitol, among other sugars, at different ratios. The Laminaria japonica hydrolysate contained up to 30.5% mannitol and 6.98% glucose in the hydrolysate solids. Ethanogenic recombinant Escherichia coli KO11 was able to utilize both mannitol and glucose and produced 0.4g ethanol per g of carbohydrate when cultured in L. japonica hydrolysate supplemented with Luria-Bertani medium and hydrolytic enzymes. The strategy of acid hydrolysis followed by simultaneous enzyme treatment and inoculation with E. coli KO11 could be a viable strategy to produce ethanol from marine alga biomass. PMID:21640583

  20. Catalytic effect of ultrananocrystalline Fe₃O₄ on algal bio-crude production via HTL process.

    PubMed

    Rojas-Pérez, Arnulfo; Diaz-Diestra, Daysi; Frias-Flores, Cecilia B; Beltran-Huarac, Juan; Das, K C; Weiner, Brad R; Morell, Gerardo; Díaz-Vázquez, Liz M

    2015-11-14

    We report a comprehensive quantitative study of the production of refined bio-crudes via a controlled hydrothermal liquefaction (HTL) process using Ulva fasciata macroalgae (UFMA) as biomass and ultrananocrystalline Fe3O4 (UNCFO) as catalyst. X-ray diffraction and electron microscopy were applied to elucidate the formation of the high-quality nanocatalysts. Gas chromatography-mass spectroscopy (GC-MS) and CHNS analyses showed that the bio-crude yield and carbon/oxygen ratios increase as the amount of UNCFO increases, reaching a peak value of 32% at 1.25 wt% (a 9% increase when compared to the catalyst-free yield). The bio-crude is mainly composed of fatty acids, alcohols, ketones, phenol and benzene derivatives, and hydrocarbons. Their relative abundance changes as a function of catalyst concentration. FTIR spectroscopy and vibrating sample magnetometry revealed that the as-produced bio-crudes are free of iron species, which accumulate in the generated bio-chars. Our findings also indicate that the energy recovery values via the HTL process are sensitive to the catalyst loading, with a threshold loading of 1.25 wt%. GC-MS studies show that the UNCFO not only influences the chemical nature of the resulting bio-crudes and bio-chars, but also the amount of fixed carbons in the solid residues. The detailed molecular characterization of the bio-crudes and bio-chars catalyzed by UNCFO represents the first systematic study reported using UFMA. This study brings forth new avenues to advance the highly-pure bio-crude production employing active, heterogeneous catalyst materials that are recoverable and recyclable for continuous thermochemical reactions.

  1. Extracellular electron transfer from cathode to microbes: application for biofuel production.

    PubMed

    Choi, Okkyoung; Sang, Byoung-In

    2016-01-01

    Extracellular electron transfer in microorganisms has been applied for bioelectrochemical synthesis utilizing microbes to catalyze anodic and/or cathodic biochemical reactions. Anodic reactions (electron transfer from microbe to anode) are used for current production and cathodic reactions (electron transfer from cathode to microbe) have recently been applied for current consumption for valuable biochemical production. The extensively studied exoelectrogenic bacteria Shewanella and Geobacter showed that both directions for electron transfer would be possible. It was proposed that gram-positive bacteria, in the absence of cytochrome C, would accept electrons using a cascade of membrane-bound complexes such as membrane-bound Fe-S proteins, oxidoreductase, and periplasmic enzymes. Modification of the cathode with the addition of positive charged species such as chitosan or with an increase of the interfacial area using a porous three-dimensional scaffold electrode led to increased current consumption. The extracellular electron transfer from the cathode to the microbe could catalyze various bioelectrochemical reductions. Electrofermentation used electrons from the cathode as reducing power to produce more reduced compounds such as alcohols than acids, shifting the metabolic pathway. Electrofuel could be generated through artificial photosynthesis using electrical energy instead of solar energy in the process of carbon fixation. PMID:26788124

  2. Extracellular acidification stimulates GPR68 mediated IL-8 production in human pancreatic β cells.

    PubMed

    Chandra, Vikash; Karamitri, Angeliki; Richards, Paul; Cormier, Françoise; Ramond, Cyrille; Jockers, Ralf; Armanet, Mathieu; Albagli-Curiel, Olivier; Scharfmann, Raphael

    2016-01-01

    Acute or chronic metabolic complications such as diabetic ketoacidosis are often associated with extracellular acidification and pancreatic β-cell dysfunction. However, the mechanisms by which human β-cells sense and respond to acidic pH remain elusive. In this study, using the recently developed human β-cell line EndoC-βH2, we demonstrate that β-cells respond to extracellular acidification through GPR68, which is the predominant proton sensing receptor of human β-cells. Using gain- and loss-of-function studies, we provide evidence that the β-cell enriched transcription factor RFX6 is a major regulator of GPR68. Further, we show that acidic pH stimulates the production and secretion of the chemokine IL-8 by β-cells through NF-кB activation. Blocking of GPR68 or NF-кB activity severely attenuated acidification induced IL-8 production. Thus, we provide mechanistic insights into GPR68 mediated β-cell response to acidic microenvironment, which could be a new target to protect β-cell against acidosis induced inflammation. PMID:27166427

  3. Research and development of shallow algal mass culture systems for the production of oils

    SciTech Connect

    Laws, E.A.

    1984-10-01

    The major accomplishment of the past nine months' work was the identification of a microalgal species which can be grown in the system on a 12-month basis without temperature control. The most promising species identified to date is a strain of platymonas sp. This strain grows rapidly at temperatures from 20/sup 0/ to 34/sup 0/C, and at salinities from 1.5 to 3.5%. Neither the lower temperature limit nor the lower salinity limit of the strain are known at this time. A factorial experiment designed to determine optimum growth conditions indicated that the optimum culture depth was 10 cm, the optimum pH about 7.5, and the optimum flow rate about 30 cm/s. A major discovery was that diluting the culture every third day greatly enhanced production. In this dilution mode daily yields averaged 46 g/m/sup 2/ ash-free dry weight (AFDW) over a one-month period, and photosynthetic efficiencies averaged 11% (based on visible light energy). The former figure is over twice the best long-term yields achieved in microalgal mass culture systems grown exclusively on inorganic nutrients.

  4. The Seeding and Cultivation of a Tropical Species of Filamentous Ulva for Algal Biomass Production

    PubMed Central

    Carl, Christina; de Nys, Rocky; Paul, Nicholas A.

    2014-01-01

    Filamentous species of Ulva are ideal for cultivation because they are robust with high growth rates and maintained across a broad range of environments. Temperate species of filamentous Ulva are commercially cultivated on nets which can be artificially ‘seeded’ under controlled conditions allowing for a high level of control over seeding density and consequently biomass production. This study quantified for the first time the seeding and culture cycle of a tropical species of filamentous Ulva (Ulva sp. 3) and identified seeding density and nursery period as key factors affecting growth and biomass yield. A seeding density of 621,000 swarmers m-1 rope in combination with a nursery period of five days resulted in the highest growth rate and correspondingly the highest biomass yield. A nursery period of five days was optimal with up to six times the biomass yield compared to ropes under either shorter or longer nursery periods. These combined parameters of seeding density and nursery period resulted in a specific growth rate of more than 65% day−1 between 7 and 10 days of outdoor cultivation post-nursery. This was followed by a decrease in growth through to 25 days. This study also demonstrated that the timing of harvest is critical as the maximum biomass yield of 23.0±8.8 g dry weight m−1 (228.7±115.4 g fresh weight m−1) was achieved after 13 days of outdoor cultivation whereas biomass degraded to 15.5±7.3 g dry weight m−1 (120.2±71.8 g fresh weight m−1) over a longer outdoor cultivation period of 25 days. Artificially seeded ropes of Ulva with high biomass yields over short culture cycles may therefore be an alternative to unattached cultivation in integrated pond-based aquaculture systems. PMID:24897115

  5. Accumulation characteristics of soluble algal products (SAP) by a freshwater microalga Scenedesmus sp. LX1 during batch cultivation for biofuel production.

    PubMed

    Yu, Yin; Hu, Hong-Ying; Li, Xin; Wu, Yin-Hu; Zhang, Xue; Jia, Sheng-Lan

    2012-04-01

    Algae cultivation is the essential basis for microalgal biofuel production. Soluble algal products (SAP) are significant obstacle to large-scale, high-cell-density cultivation processes. SAP accumulation during batch cultivation of Scenedesmus sp. LX1 (a unique strain accumulating lipid substantially while growing fast under low-nutrient conditions) with different initial nitrogen concentrations (7.4-34.0mgNL(-1)) was investigated. The SAP content varied in the range of 3.4-17.4mgDOCL(-1) at stationary phase, with average yield per cell of 0.5-2.5pgDOCcell(-1). High SAP accumulation up to 15.2-17.4mgDOCL(-1) were observed with initial nitrogen above 20.2mgNL(-1). The maximum SAP production rate per unit culture volume (r(SAP)) was 2.6mgDOC(Ld)(-1) and that per cell (ν(SAP)) was 1.5pgDOC(celld)(-1). The r(SAP) increased with cell growth rate and decreased with cell density linearly. The SAP accumulation was majorly due to the release of growth-associated products.

  6. Influences of environmental factors on bacterial extracellular polymeric substances production in porous media

    NASA Astrophysics Data System (ADS)

    Xia, Lu; Zheng, Xilai; Shao, Haibing; Xin, Jia; Peng, Tao

    2014-11-01

    Bioclogging of natural porous media occurs frequently under a wide range of conditions. It may influence the performance of permeable reactive barrier and constructed wetland. It is also one of the factors that determine the effect of artificial groundwater recharge and in situ bioremediation process. In this study, a series of percolation column experiments were conducted to simulate bioclogging process in porous media. The predominant bacteria in porous media which induced clogging were identified to be Methylobacterium, Janthinobacterium, Yersinia, Staphylococcus and Acidovorax, most of which had been shown to effectively produce viscous extracellular polymeric substances (EPS). The column in which EPS production was maximized also coincided with the largest reduction in saturated hydraulic conductivity of porous media. In addition, carbon concentration was the most significant factor to affect polysaccharide, protein and EPS secretion, followed by phosphorus concentration and temperature. The coupled effect of carbon and phosphorus concentration was also very important to stimulate polysaccharide and EPS production.

  7. Extracellular peroxidase production by Coprinus species from urea-treated soil.

    PubMed

    Ikehata, Keisuke; Buchanan, Ian D; Smith, Daniel W

    2004-01-01

    Thirteen strains of inky-cap mushroom Coprinus species were evaluated for the production of extracellular peroxidase. The liquid fermentation was carried out in shake flasks containing 1% glucose, 0.5% peptone, 0.3% yeast extract, and 0.3% malt extract broth at 25 degrees C. Peroxidase activity was detected in the liquid culture of several Coprinus species, including C. echinosporus NBRC 30630; C. macrocephalus NBRC 30117; Coprinus spp. UAMH 10065, UAMH 10066, UAMH 10067, and 074, after 10 days of growth. Peroxidase production by Coprinus sp. UAMH 10067, a Coprinus species isolated from urea-treated soil, was comparable to that of C. cinereus and reached 15 U.mL(-1) after 10 days. In addition, the peroxidase from Coprinus sp. UAMH 10067 was apparently more thermally stable than the enzyme produced by C. cinereus.

  8. Species-level variability in extracellular production rates of reactive oxygen species by diatoms

    NASA Astrophysics Data System (ADS)

    Schneider, Robin; Roe, Kelly; Hansel, Colleen; Voelker, Bettina

    2016-03-01

    Biological production and decay of the reactive oxygen species (ROS) hydrogen peroxide (H2O2) and superoxide (O2-) likely have significant effects on the cycling of trace metals and carbon in marine systems. In this study, extracellular production rates of H2O2 and O2- were determined for five species of marine diatoms in the presence and absence of light. Production of both ROS was measured in parallel by suspending cells on filters and measuring the ROS downstream using chemiluminescence probes. In addition, the ability of these organisms to break down O2- and H2O2 was examined by measuring recovery of O2- and H2O2 added to the influent medium. O2- production rates ranged from undetectable to 7.3 x 10-16 mol cell-1 hr-1, while H2O2 production rates ranged from undetectable to 3.4 x 10-16 mol cell-1 hr-1. Results suggest that extracellular ROS production occurs through a variety of pathways even amongst organisms of the same genus. Thalassiosira spp. produced more O2- in light than dark, even when the organisms were killed, indicating that O2- is produced via a passive photochemical process on the cell surface. The ratio of H2O¬2 to O2- production rates was consistent with production of H2O2 solely through dismutation of O2- for T. oceanica, while T. pseudonana made much more H2O2 than O2 . T. weissflogii only produced H2O2 when stressed or killed. P. tricornutum cells did not make cell-associated ROS, but did secrete H2O2-producing substances into the growth medium. In all organisms, recovery rates for killed cultures (94-100% H2O2; 10-80% O2-) were consistently higher than those for live cultures (65-95% H2O2; 10-50% O2-). While recovery rates for killed cultures in H2O2 indicate that nearly all H2O2 was degraded by active cell processes, O2- decay appeared to occur via a combination of active and passive processes. Overall, this study shows that the rates and pathways for ROS production and decay vary greatly among diatom species, even between those that are

  9. Species-Level Variability in Extracellular Production Rates of Reactive Oxygen Species by Diatoms.

    PubMed

    Schneider, Robin J; Roe, Kelly L; Hansel, Colleen M; Voelker, Bettina M

    2016-01-01

    Biological production and decay of the reactive oxygen species (ROS) hydrogen peroxide (H2O2) and superoxide (O[Formula: see text]) likely have significant effects on the cycling of trace metals and carbon in marine systems. In this study, extracellular production rates of H2O2 and O[Formula: see text] were determined for five species of marine diatoms in the presence and absence of light. Production of both ROS was measured in parallel by suspending cells on filters and measuring the ROS downstream using chemiluminescence probes. In addition, the ability of these organisms to break down O[Formula: see text] and H2O2 was examined by measuring recovery of O[Formula: see text] and H2O2 added to the influent medium. O[Formula: see text] production rates ranged from undetectable to 7.3 × 10(-16) mol cell(-1) h(-1), while H2O2 production rates ranged from undetectable to 3.4 × 10(-16) mol cell(-1) h(-1). Results suggest that extracellular ROS production occurs through a variety of pathways even amongst organisms of the same genus. Thalassiosira spp. produced more O[Formula: see text] in light than dark, even when the organisms were killed, indicating that O[Formula: see text] is produced via a passive photochemical process on the cell surface. The ratio of H2O2 to O[Formula: see text] production rates was consistent with production of H2O2 solely through dismutation of O[Formula: see text] for T. oceanica, while T. pseudonana made much more H2O2 than O[Formula: see text]. T. weissflogii only produced H2O2 when stressed or killed. P. tricornutum cells did not make cell-associated ROS, but did secrete H2O2-producing substances into the growth medium. In all organisms, recovery rates for killed cultures (94-100% H2O2; 10-80% O[Formula: see text]) were consistently higher than those for live cultures (65-95% H2O2; 10-50% O[Formula: see text]). While recovery rates for killed cultures in H2O2 indicate that nearly all H2O2 was degraded by active cell processes, O

  10. Species-Level Variability in Extracellular Production Rates of Reactive Oxygen Species by Diatoms

    PubMed Central

    Schneider, Robin J.; Roe, Kelly L.; Hansel, Colleen M.; Voelker, Bettina M.

    2016-01-01

    Biological production and decay of the reactive oxygen species (ROS) hydrogen peroxide (H2O2) and superoxide (O2-) likely have significant effects on the cycling of trace metals and carbon in marine systems. In this study, extracellular production rates of H2O2 and O2- were determined for five species of marine diatoms in the presence and absence of light. Production of both ROS was measured in parallel by suspending cells on filters and measuring the ROS downstream using chemiluminescence probes. In addition, the ability of these organisms to break down O2- and H2O2 was examined by measuring recovery of O2- and H2O2 added to the influent medium. O2- production rates ranged from undetectable to 7.3 × 10−16 mol cell−1 h−1, while H2O2 production rates ranged from undetectable to 3.4 × 10−16 mol cell−1 h−1. Results suggest that extracellular ROS production occurs through a variety of pathways even amongst organisms of the same genus. Thalassiosira spp. produced more O2- in light than dark, even when the organisms were killed, indicating that O2- is produced via a passive photochemical process on the cell surface. The ratio of H2O2 to O2- production rates was consistent with production of H2O2 solely through dismutation of O2- for T. oceanica, while T. pseudonana made much more H2O2 than O2-. T. weissflogii only produced H2O2 when stressed or killed. P. tricornutum cells did not make cell-associated ROS, but did secrete H2O2-producing substances into the growth medium. In all organisms, recovery rates for killed cultures (94–100% H2O2; 10–80% O2-) were consistently higher than those for live cultures (65–95% H2O2; 10–50% O2-). While recovery rates for killed cultures in H2O2 indicate that nearly all H2O2 was degraded by active cell processes, O2- decay appeared to occur via a combination of active and passive processes. Overall, this study shows that the rates and pathways for ROS production and decay vary greatly among diatom species, even

  11. Constraints to commercialization of algal fuels.

    PubMed

    Chisti, Yusuf

    2013-09-10

    Production of algal crude oil has been achieved in various pilot scale facilities, but whether algal fuels can be produced in sufficient quantity to meaningfully displace petroleum fuels, has been largely overlooked. Limitations to commercialization of algal fuels need to be understood and addressed for any future commercialization. This review identifies the major constraints to commercialization of transport fuels from microalgae. Algae derived fuels are expensive compared to petroleum derived fuels, but this could change. Unfortunately, improved economics of production are not sufficient for an environmentally sustainable production, or its large scale feasibility. A low-cost point supply of concentrated carbon dioxide colocated with the other essential resources is necessary for producing algal fuels. An insufficiency of concentrated carbon dioxide is actually a major impediment to any substantial production of algal fuels. Sustainability of production requires the development of an ability to almost fully recycle the phosphorous and nitrogen nutrients that are necessary for algae culture. Development of a nitrogen biofixation ability to support production of algal fuels ought to be an important long term objective. At sufficiently large scale, a limited supply of freshwater will pose a significant limitation to production even if marine algae are used. Processes for recovering energy from the algal biomass left after the extraction of oil, are required for achieving a net positive energy balance in the algal fuel oil. The near term outlook for widespread use of algal fuels appears bleak, but fuels for niche applications such as in aviation may be likely in the medium term. Genetic and metabolic engineering of microalgae to boost production of fuel oil and ease its recovery, are essential for commercialization of algal fuels. Algae will need to be genetically modified for improved photosynthetic efficiency in the long term. PMID:23886651

  12. Extracellular α-Galactosidase from Trichoderma sp. (WF-3): Optimization of Enzyme Production and Biochemical Characterization

    PubMed Central

    Chauhan, Aishwarya Singh; Kumar, Arunesh; Siddiqi, Nikhat J.; Sharma, B.

    2015-01-01

    Trichoderma spp. have been reported earlier for their excellent capacity of secreting extracellular α-galactosidase. This communication focuses on the optimization of culture conditions for optimal production of enzyme and its characterization. The evaluation of the effects of different enzyme assay parameters such as stability, pH, temperature, substrate concentrations, and incubation time on enzyme activity has been made. The most suitable buffer for enzyme assay was found to be citrate phosphate buffer (50 mM, pH 6.0) for optimal enzyme activity. This enzyme was fairly stable at higher temperature as it exhibited 72% activity at 60°C. The enzyme when incubated at room temperature up to two hours did not show any significant loss in activity. It followed Michaelis-Menten curve and showed direct relationship with varying substrate concentrations. Higher substrate concentration was not inhibitory to enzyme activity. The apparent Michaelis-Menten constant (Km), maximum rate of reaction (Vmax), Kcat, and catalytic efficiency values for this enzyme were calculated from the Lineweaver-Burk double reciprocal plot and were found to be 0.5 mM, 10 mM/s, 1.30 U mg−1, and 2.33 U mg−1 mM−1, respectively. This information would be helpful in understanding the biophysical and biochemical characteristics of extracellular α-galactosidase from other microbial sources. PMID:26609435

  13. Extracellular production of Pseudozyma (Candida) antarctica lipase B with genuine primary sequence in recombinant Escherichia coli.

    PubMed

    Ujiie, Ayana; Nakano, Hideo; Iwasaki, Yugo

    2016-03-01

    An Escherichia coli expression system was established to produce recombinant extracellular Pseudozyma (Candida) antarctica lipase B (CALB). With the aim of producing the genuine CALB without additional amino acid residues, the mature portion of the CALB gene was fused seamlessly to a pelB signal sequence and expressed in E. coli BL21(DE3) using the pET system. Inducing gene expression at low temperature (20°C) was crucial for the production of active CALB; higher temperatures caused inclusion body formation. Prolonged induction for 48 h at 20°C allowed for the enzyme to be released into the culture medium, with more than half of the activity detected in the culture supernatant. A catalytically inactive CALB mutant (S105A) protein was similarly released, suggesting that the lipid-hydrolyzing activity of the enzyme was not the reason for the release. The CALB production level was further improved by optimizing the culture medium. Under the optimized conditions, the CALB in the culture supernatant amounted to 550 mg/L. The recombinant CALB was purified from the culture supernatant, yielding 5.67 mg of purified CALB from 50 mL of culture. N-terminal sequencing and ESI-MS analyses showed proper removal of the pelB signal sequence and the correct molecular weight of the protein, respectively, confirming the structural integrity of the recombinant CALB. The kinetic parameters towards p-nitrophenylbutyrate and the enantiomeric selectivity on rac-1-phenylethylacetate of the recombinant CALB were consistent with those of the authentic CALB. This is the first example of E. coli-based extracellular production of a CALB enzyme without extra amino acid residues.

  14. NG2 proteoglycan increases mesangial cell proliferation and extracellular matrix production

    SciTech Connect

    Xiong Jing; Wang Yang; Zhu, Zhonghua; Liu Jianshe; Wang Yumei; Zhang Chun; Hammes, Hans-Peter; Lang, Florian; Feng Yuxi

    2007-10-05

    As a membrane-spanning protein, NG2 chondroitin sulfate proteoglycan interacts with molecules on both sides of plasma membrane. The present study explored the role of NG2 in the pathogenesis of diabetic nephropathy. In the normal kidneys, NG2 was observed predominantly in glomerular mesangium, Bowman's capsule and interstitial vessels. Both mRNA and protein expression in kidneys was significantly higher in strepozotocin-induced diabetic rats than that in normal rats. In the cultured rat mesangial cell line HBZY-1, overexpression of NG2 promoted mesangial cell proliferation and extracellular matrix (ECM) production, such as type VI collagen and laminin. Furthermore, target knockdown of NG2 resulted in decreased cell proliferation and ECM formation. The observations suggest that NG2 is up-regulated in diabetic nephropathy. It actively participates in the development and progression of glomerulosclerosis by stimulating proliferation of mesangial cells and deposition of ECM.

  15. Production, purification and application of extracellular chitinase from Cellulosimicrobium cellulans 191

    PubMed Central

    Fleuri, Luciana F.; Kawaguti, Haroldo Y.; Sato, Hélia H.

    2009-01-01

    This study concerned the production, purification and application of extracellular chitinase from Cellulosimicrobium cellulans strain 191. In shaken flasks the maximum yield of chitinase was 6.9 U/mL after 72 h of cultivation at 25°C and 200 rpm. In a 5 L fermenter with 1.5 vvm aeration, the highest yield obtained was 4.19 U/mL after 168 h of fermentation at 25°C and 200 rpm, and using 3 vvm, it was 4.38 U/mL after 144 h of fermentation. The chitinase (61 KDa) was purified about 6.65 times by Sepharose CL 4B 200 gel filtration with a yield of 46.61%. The purified enzyme was able to lyse the cell walls of some fungi and to form protoplasts. PMID:24031407

  16. Capsular polysaccharides from Cryptococcus neoformans modulate production of neutrophil extracellular traps (NETs) by human neutrophils.

    PubMed

    Rocha, Juliana D B; Nascimento, Michelle T C; Decote-Ricardo, Debora; Côrte-Real, Suzana; Morrot, Alexandre; Heise, Norton; Nunes, Marise P; Previato, José Osvaldo; Mendonça-Previato, Lucia; DosReis, George A; Saraiva, Elvira M; Freire-de-Lima, Célio G

    2015-01-01

    In the present study, we characterized the in vitro modulation of NETs (neutrophil extracellular traps) induced in human neutrophils by the opportunistic fungus Cryptococcus neoformans, evaluating the participation of capsular polysaccharides glucuronoxylomanan (GXM) and glucuronoxylomannogalactan (GXMGal) in this phenomenon. The mutant acapsular strain CAP67 and the capsular polysaccharide GXMGal induced NET production. In contrast, the wild-type strain and the major polysaccharide GXM did not induce NET release. In addition, C. neoformans and the capsular polysaccharide GXM inhibited PMA-induced NET release. Additionally, we observed that the NET-enriched supernatants induced through CAP67 yeasts showed fungicidal activity on the capsular strain, and neutrophil elastase, myeloperoxidase, collagenase and histones were the key components for the induction of NET fungicidal activity. The signaling pathways associated with NET induction through the CAP67 strain were dependent on reactive oxygen species (ROS) and peptidylarginine deiminase-4 (PAD-4). Neither polysaccharide induced ROS production however both molecules blocked the production of ROS through PMA-activated neutrophils. Taken together, the results demonstrate that C. neoformans and the capsular component GXM inhibit the production of NETs in human neutrophils. This mechanism indicates a potentially new and important modulation factor for this fungal pathogen. PMID:25620354

  17. Optimization of Fermentation Medium for Extracellular Lipase Production from Aspergillus niger Using Response Surface Methodology.

    PubMed

    Jia, Jia; Yang, Xiaofeng; Wu, Zhiliang; Zhang, Qian; Lin, Zhi; Guo, Hongtao; Lin, Carol Sze Ki; Wang, Jianying; Wang, Yunshan

    2015-01-01

    Lipase produced by Aspergillus niger is widely used in various industries. In this study, extracellular lipase production from an industrial producing strain of A. niger was improved by medium optimization. The secondary carbon source, nitrogen source, and lipid were found to be the three most influential factors for lipase production by single-factor experiments. According to the statistical approach, the optimum values of three most influential parameters were determined: 10.5 g/L corn starch, 35.4 g/L soybean meal, and 10.9 g/L soybean oil. Using this optimum medium, the best lipase activity was obtained at 2,171 U/mL, which was 16.4% higher than using the initial medium. All these results confirmed the validity of the model. Furthermore, results of the Box-Behnken Design and quadratic models analysis indicated that the carbon to nitrogen (C/N) ratio significantly influenced the enzyme production, which also suggested that more attention should be paid to the C/N ratio for the optimization of enzyme production. PMID:26366414

  18. Extracellular enzyme production and cheating in Pseudomonas fluorescens depend on diffusion rates.

    PubMed

    Allison, Steven D; Lu, Lucy; Kent, Alyssa G; Martiny, Adam C

    2014-01-01

    Bacteria produce extracellular enzymes to obtain resources from complex chemical substrates, but this strategy is vulnerable to cheating by cells that take up reaction products without paying the cost of enzyme production. We hypothesized that cheating would suppress enzyme production in co-cultures of cheater and producer bacteria, particularly under well-mixed conditions. To test this hypothesis, we monitored protease expression and frequencies of Pseudomonas fluorescens producer and cheater genotypes over time in mixed liquid cultures and on agar plates. In mixed culture inoculated with equal frequencies of cheaters and producers, enzyme concentration declined to zero after 20 days, consistent with our hypothesis. We observed a similar decline in cultures inoculated with producers only, suggesting that cheater mutants arose de novo and swept the population. DNA sequencing showed that genetic changes most likely occurred outside the protease operon. In one experimental replicate, the population regained the ability to produce protease, likely due to further genetic changes or population dynamics. Under spatially structured conditions on agar plates, cheaters did not sweep the population. Instead, we observed a significant increase in the variation of enzyme activity levels expressed by clones isolated from the population. Together these results suggest that restricted diffusion favors a diversity of enzyme production strategies. In contrast, well-mixed conditions favor population sweeps by cheater strains, consistent with theoretical predictions. Cheater and producer strategies likely coexist in natural environments with the frequency of cheating increasing with diffusion rate.

  19. Optimization of Fermentation Medium for Extracellular Lipase Production from Aspergillus niger Using Response Surface Methodology

    PubMed Central

    Jia, Jia; Yang, Xiaofeng; Wu, Zhiliang; Zhang, Qian; Lin, Zhi; Guo, Hongtao; Lin, Carol Sze Ki; Wang, Jianying; Wang, Yunshan

    2015-01-01

    Lipase produced by Aspergillus niger is widely used in various industries. In this study, extracellular lipase production from an industrial producing strain of A. niger was improved by medium optimization. The secondary carbon source, nitrogen source, and lipid were found to be the three most influential factors for lipase production by single-factor experiments. According to the statistical approach, the optimum values of three most influential parameters were determined: 10.5 g/L corn starch, 35.4 g/L soybean meal, and 10.9 g/L soybean oil. Using this optimum medium, the best lipase activity was obtained at 2,171 U/mL, which was 16.4% higher than using the initial medium. All these results confirmed the validity of the model. Furthermore, results of the Box-Behnken Design and quadratic models analysis indicated that the carbon to nitrogen (C/N) ratio significantly influenced the enzyme production, which also suggested that more attention should be paid to the C/N ratio for the optimization of enzyme production. PMID:26366414

  20. Extracellular enzyme production and cheating in Pseudomonas fluorescens depend on diffusion rates

    PubMed Central

    Allison, Steven D.; Lu, Lucy; Kent, Alyssa G.; Martiny, Adam C.

    2014-01-01

    Bacteria produce extracellular enzymes to obtain resources from complex chemical substrates, but this strategy is vulnerable to cheating by cells that take up reaction products without paying the cost of enzyme production. We hypothesized that cheating would suppress enzyme production in co-cultures of cheater and producer bacteria, particularly under well-mixed conditions. To test this hypothesis, we monitored protease expression and frequencies of Pseudomonas fluorescens producer and cheater genotypes over time in mixed liquid cultures and on agar plates. In mixed culture inoculated with equal frequencies of cheaters and producers, enzyme concentration declined to zero after 20 days, consistent with our hypothesis. We observed a similar decline in cultures inoculated with producers only, suggesting that cheater mutants arose de novo and swept the population. DNA sequencing showed that genetic changes most likely occurred outside the protease operon. In one experimental replicate, the population regained the ability to produce protease, likely due to further genetic changes or population dynamics. Under spatially structured conditions on agar plates, cheaters did not sweep the population. Instead, we observed a significant increase in the variation of enzyme activity levels expressed by clones isolated from the population. Together these results suggest that restricted diffusion favors a diversity of enzyme production strategies. In contrast, well-mixed conditions favor population sweeps by cheater strains, consistent with theoretical predictions. Cheater and producer strategies likely coexist in natural environments with the frequency of cheating increasing with diffusion rate. PMID:24782855

  1. The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production.

    PubMed

    Xu, Chunyan; Wu, Kangyan; Van Ginkel, Steve W; Igou, Thomas; Lee, Hwa Jong; Bhargava, Aditya; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-11-17

    Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS), on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office's (BETO) projected cost of $5/gge (gallon gasoline equivalent). This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes.

  2. The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production

    PubMed Central

    Xu, Chunyan; Wu, Kangyan; Van Ginkel, Steve W.; Igou, Thomas; Lee, Hwa Jong; Bhargava, Aditya; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-01-01

    Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS), on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office’s (BETO) projected cost of $5/gge (gallon gasoline equivalent). This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes. PMID:26593899

  3. The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production.

    PubMed

    Xu, Chunyan; Wu, Kangyan; Van Ginkel, Steve W; Igou, Thomas; Lee, Hwa Jong; Bhargava, Aditya; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-01-01

    Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS), on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office's (BETO) projected cost of $5/gge (gallon gasoline equivalent). This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes. PMID:26593899

  4. Guidance values for microcystins in water and cyanobacterial supplement products (blue-green algal supplements): a reasonable or misguided approach?

    SciTech Connect

    Dietrich, Daniel; Hoeger, Stefan . E-mail: stefan.hoeger@uni-konstanz.de

    2005-03-15

    This article reviews current scientific knowledge on the toxicity and carcinogenicity of microcystins and compares this to the guidance values proposed for microcystins in water by the World Health Organization, and for blue-green algal food supplements by the Oregon State Department of Health. The basis of the risk assessment underlying these guidance values is viewed as being critical due to overt deficiencies in the data used for its generation: (i) use of one microcystin congener only (microcystin-LR), while the other presently known nearly 80 congeners are largely disregarded, (ii) new knowledge regarding potential neuro and renal toxicity of microcystins in humans and (iii) the inadequacies of assessing realistic microcystin exposures in humans and especially in children via blue-green algal food supplements. In reiterating the state-of-the-art toxicology database on microcystins and in the light of new data on the high degree of toxin contamination of algal food supplements, this review clearly demonstrates the need for improved kinetic data of microcystins in humans and for discussion concerning uncertainty factors, which may result in a lowering of the present guidance values and an increased routine control of water bodies and food supplements for toxin contamination. Similar to the approach taken previously by authorities for dioxin or PCB risk assessment, the use of a toxin equivalent approach to the risk assessment of microcystins is proposed.

  5. Direct Regulation of Extracellular Chitinase Production by the Transcription Factor LeClp in Lysobacter enzymogenes OH11.

    PubMed

    Xu, Huiyong; Chen, Hongfu; Shen, Yuemao; Du, Liangcheng; Chou, Shan-Ho; Liu, Hongxia; Qian, Guoliang; Liu, Fengquan

    2016-09-01

    Lysobacter enzymogenes is a gram-negative bacterial biological control agent that produces abundant extracellular enzymes capable of degrading the cell walls of fungal pathogens. In strain OH11, an isolate from China, the global regulator LeClp controls the production of extracellular chitinase by regulating the transcription of the chitinase-encoding gene chiA. Using a combination of bioinformatic, genetic, and biochemical methods, we show that LeClp regulates chiA transcription by directly binding to the chiA promoter region. Although LeClp appears to be important in this role, it is not the sole regulator of chiA transcription. Furthermore, the sequence analysis of putative LeClp binding sites indicated that the LeClp homolog could be involved in the regulation of extracellular chitinase production in diverse Lysobacter spp. by a mechanism similar to that in L. enzymogenes. Our findings present new insights into the molecular mechanism of LeClp in controlling extracellular chitinase activity, providing a fundamental road to elucidate how LeClp regulates the production of other extracellular lytic enzymes in L. enzymogenes. PMID:27385597

  6. Inhibitory effects of extracellular products from oral bacteria on human fibroblasts and stimulated lymphocytes.

    PubMed Central

    Higerd, T B; Vesole, D H; Goust, J M

    1978-01-01

    Extracellular products of 12 strains of Streptococcus mutans and 5 additional species of oral bacteria were analyzed for their ability to inhibit proliferation of fibroblastoid cells (HeLa and AV3) and blast transformation of human peripheral blood lymphocytes obtained from normal individuals. Products from S. mutans strains AHT and BHT, Streptococcus intermedius, and Actinomyces viscosus inhibited [3H]thymidine uptake by fibroblastoid cells and phytohemagglutinin-stimulated lymphocytes. Products from S. mutans E49, Streptococcus salivarius, and Actinomyces naeslundii inhibited blast transformation of human lymphocytes but did not significantly inhibit the growth of fibroblastoid cells. Preparations from S. intermedius gave the greatest inhibitory activity against both target cell types; initial characterization of this preparation suggested a single factor active in both assays, in that the heat lability and Sephadex G-200 elution profile were similar for the inhibitory activity seen with the two cell types. The molecular weight of the inhibitor, estimated by gel filtration on Sephadex G-200 and Ultragel AcA34, was approximately 160,000. The results strongly suggest that oral bacteria produce heat-labile substances that interfere with fibroblast proliferation and alter the lymphocytic immunological response. Images PMID:689736

  7. Inhibitory effects of extracellular products from oral bacteria on human fibroblasts and stimulated lymphocytes.

    PubMed

    Higerd, T B; Vesole, D H; Goust, J M

    1978-08-01

    Extracellular products of 12 strains of Streptococcus mutans and 5 additional species of oral bacteria were analyzed for their ability to inhibit proliferation of fibroblastoid cells (HeLa and AV3) and blast transformation of human peripheral blood lymphocytes obtained from normal individuals. Products from S. mutans strains AHT and BHT, Streptococcus intermedius, and Actinomyces viscosus inhibited [3H]thymidine uptake by fibroblastoid cells and phytohemagglutinin-stimulated lymphocytes. Products from S. mutans E49, Streptococcus salivarius, and Actinomyces naeslundii inhibited blast transformation of human lymphocytes but did not significantly inhibit the growth of fibroblastoid cells. Preparations from S. intermedius gave the greatest inhibitory activity against both target cell types; initial characterization of this preparation suggested a single factor active in both assays, in that the heat lability and Sephadex G-200 elution profile were similar for the inhibitory activity seen with the two cell types. The molecular weight of the inhibitor, estimated by gel filtration on Sephadex G-200 and Ultragel AcA34, was approximately 160,000. The results strongly suggest that oral bacteria produce heat-labile substances that interfere with fibroblast proliferation and alter the lymphocytic immunological response. PMID:689736

  8. Production and characterization of an extracellular polysaccharide from Streptomyces violaceus MM72.

    PubMed

    Manivasagan, Panchanathan; Sivasankar, Palaniappan; Venkatesan, Jayachandran; Senthilkumar, Kalimuthu; Sivakumar, Kannan; Kim, Se-Kwon

    2013-08-01

    The isolation, optimization, purification and characterization of an extracellular polysaccharide (EPS) from a marine actinobacterium, Streptomyces violaceus MM72 were investigated. Medium composition and culture conditions for the EPS production by S. violaceus MM72 were optimized using two statistical methods: Plackett-Burman design applied to find the key ingredients and conditions for the best yield of EPS production and central composite design used to optimize the concentration of the three significant variables: glucose, tryptone and NaCl. The preferable culture conditions for EPS production were pH 7.0, temperature 35°C and NaCl concentration 2.0% for 120h with fructose and yeast extract as best carbon and nitrogen sources, respectively. The results showed that S. violaceus MM72 produced a kind of EPS having molecular weight of 8.96×10(5)Da. In addition, the EPS showed strong DPPH radical-scavenging activity, superoxide scavenging and metal chelating activities while moderate inhibition of lipid peroxidation and reducing activities determined in this study. These results showed the great potential of EPS produced by S. violaceus MM72 could be used in industry in place of synthetic compounds. The EPS from S. violaceus MM72 may be a new source of natural antioxidants with potential value for health, food and therapeutics. PMID:23597709

  9. Production of extracellular polysaccharide by Bacillus megaterium RB-05 using jute as substrate.

    PubMed

    Chowdhury, Sougata Roy; Basak, Ratan Kumar; Sen, Ramkrishna; Adhikari, Basudam

    2011-06-01

    Bacillus megaterium RB-05 was grown on glucose and on "tossa-daisee" (Corchorus olitorius)-derived jute, and production and composition of extracellular polysaccharide (EPS) were monitored. An EPS yield of 0.065 ± 0.013 and of 0.297 g ± 0.054 g(-1) substrate after 72 h was obtained for glucose and jute, respectively. EPS production in the presence of jute paralleled bacterial cellulase activity. High performance liquid chromatography (HPLC), matrix assisted LASER desorption/ionization-time of flight (MALDI-ToF) mass spectroscopy, and fourier transform infrared (FT-IR) spectroscopy demonstrated that the EPS synthesized in jute culture (JC) differed from that synthesized in glucose mineral salts medium (GMSM). While fucose was only a minor constituent (4.9 wt.%) of EPS from GMSM, it a major component (41.9 wt.%) of EPS synthesized in JC. This study establishes jute as an effective fermentation substrate for EPS production by a cellulase-producing bacterium.

  10. Enhancement of sludge reduction and methane production by removing extracellular polymeric substances from waste activated sludge.

    PubMed

    Nguyen, Minh Tuan; Mohd Yasin, Nazlina Haiza; Miyazaki, Toshiki; Maeda, Toshinari

    2014-12-01

    The management of waste activated sludge (WAS) recycling is a concern that affects the development of the future low-carbon society, particularly sludge reduction and biomass utilization. In this study, we investigated the effect of removing extracellular polymeric substances (EPS), which play important roles in the adhesion and flocculation of WAS, on increased sludge disintegration, thereby enhancing sludge reduction and methane production by anaerobic digestion. EPS removal from WAS by ethylenediaminetetraacetic acid (EDTA) significantly enhanced sludge reduction, i.e., 49 ± 5% compared with 27 ± 1% of the control at the end the digestion process. Methane production was also improved in WAS without EPS by 8881 ± 109 CH4 μmol g(-1) dry-weight of sludge. Microbial activity was determined by denaturing gradient gel electrophoresis and real-time polymerase chain reaction, which showed that the hydrolysis and acetogenesis stages were enhanced by pretreatment with 2% EDTA, with a larger methanogenic community and better methane production. PMID:25277968

  11. A GIS COST MODEL TO ASSESS THE AVAILABILITY OF FRESHWATER, SEAWATER, AND SALINE GROUNDWATER FOR ALGAL BIOFUEL PRODUCTION IN THE UNITED STATES

    SciTech Connect

    Venteris, Erik R.; Skaggs, Richard; Coleman, Andre M.; Wigmosta, Mark S.

    2013-03-15

    A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a limited techno-economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply, and cost models for supplying seawater and saline groundwater. We estimate that combined, within the coterminous US these resources can support production on the order of 9.46E+7 m3 yr-1 (25 billion gallons yr-1) of renewable biodiesel. Achievement of larger targets requires the utilization of less water efficient sites and relatively expensive saline waters. Geographically, water availability is most favorable for the coast of the Gulf of Mexico and Florida peninsula, where evaporation relative to precipitation is moderate and various saline waters are economically available. As a whole, barren and scrub lands of the southwestern US have limited freshwater supplies so accurate assessment of alternative waters is critical.

  12. Optimizing production of asperolide A, a potential anti-tumor tetranorditerpenoid originally produced by the algal-derived endophytic fungus Aspergillus wentii EN-48

    NASA Astrophysics Data System (ADS)

    Xu, Rui; Li, Xiaoming; Xu, Gangming; Wang, Bingui

    2016-07-01

    The marine algal-derived endophytic fungus Aspergillus wentii EN-48 produces the potential anti-tumor agent asperolide A, a tetranorlabdane diterpenoid active against lung cancer. However, the fermentation yield of asperolide A was very low and only produced in static cultures. Static fermentation conditions of A. wentii EN-48 were optimized employing response surface methodology to enhance the production of asperolide A. The optimized conditions resulted in a 13.9-fold yield enhancement, which matched the predicted value, and the optimized conditions were successfully used in scale-up fermentation for the production of asperolide A. Exogenous addition of plant hormones (especially 10 μmol/L methyl jasmonate) stimulated asperolide A production. To our knowledge, this is first optimized production of an asperolide by a marine-derived fungus. The optimization is Effective and valuable to supply material for further anti-tumor mechanism studies and preclinical evaluation of asperolide A and other norditerpenoids.

  13. In search of actionable targets for agrigenomics and microalgal biofuel production: sequence-structural diversity studies on algal and higher plants with a focus on GPAT protein.

    PubMed

    Misra, Namrata; Panda, Prasanna Kumar

    2013-04-01

    The triacylglycerol (TAG) pathway provides several targets for genetic engineering to optimize microalgal lipid productivity. GPAT (glycerol-3-phosphate acyltransferase) is a crucial enzyme that catalyzes the initial step of TAG biosynthesis. Despite many recent biochemical studies, a comprehensive sequence-structure analysis of GPAT across diverse lipid-yielding organisms is lacking. Hence, we performed a comparative genomic analysis of plastid-located GPAT proteins from 7 microalgae and 3 higher plants species. The close evolutionary relationship observed between red algae/diatoms and green algae/plant lineages in the phylogenetic tree were further corroborated by motif and gene structure analysis. The predicted molecular weight, amino acid composition, Instability Index, and hydropathicity profile gave an overall representation of the biochemical features of GPAT protein across the species under study. Furthermore, homology models of GPAT from Chlamydomonas reinhardtii, Arabidopsis thaliana, and Glycine max provided deep insights into the protein architecture and substrate binding sites. Despite low sequence identity found between algal and plant GPATs, the developed models exhibited strikingly conserved topology consisting of 14α helices and 9β sheets arranged in two domains. However, subtle variations in amino acids of fatty acyl binding site were identified that might influence the substrate selectivity of GPAT. Together, the results will provide useful resources to understand the functional and evolutionary relationship of GPAT and potentially benefit in development of engineered enzyme for augmenting algal biofuel production.

  14. Evaluation of internal loading and water level changes: implications for phosphorus, algal production, and nuisance blooms in Kabetogama Lake, Voyageurs National Park, Minnesota

    USGS Publications Warehouse

    Christensen, Victoria G.; Maki, Ryan P.; Kiesling, Richard L.

    2013-01-01

    Hydrologic manipulations have the potential to exacerbate or remediate eutrophication in productive reservoirs. Dam operations at Kabetogama Lake, Minnesota, were modified in 2000 to restore a more natural water regime and improve water quality. The US Geological Survey and National Park Service evaluated nutrient, algae, and nuisance bloom data in relation to changes in Kabetogama Lake water levels. Comparison of the results of this study to previous studies indicates that chlorophyll a concentrations have decreased, whereas total phosphorus (TP) concentrations have not changed significantly since 2000. Water and sediment quality data were collected at Voyageurs National Park during 2008–2009 to assess internal phosphorus loading and determine whether loading is a factor affecting TP concentrations and algal productivity. Kabetogama Lake often was mixed vertically, except for occasional stratification measured in certain areas, including Lost Bay in the northeastern part of Kabetogama Lake. Stratification, higher bottom water and sediment nutrient concentrations than in other parts of the lake, and phosphorus release rates estimated from sediment core incubations indicated that Lost Bay is one of several areas that may be contributing to internal loading. Internal loading of TP is a concern because increased TP may cause excessive algal growth including potentially toxic cyanobacteria.

  15. Solid state fermentation for extracellular polysaccharide production by Lactobacillus confusus with coconut water and sugar cane juice as renewable wastes.

    PubMed

    Seesuriyachan, Phisit; Techapun, Charin; Shinkawa, Hidenori; Sasaki, Ken

    2010-01-01

    Extracellular polysaccharide (EPS) production by Lactobacillus confusus in liquid and solid state fermentation was carried out using coconut water and sugarcane juice as renewable wastes. High concentrations of EPS of 62 (sugarcane juice) and 18 g/l of coconut water were produced in solid state fermentation when nitrogen sources were reduced 5-fold from the original medium.

  16. Vaccination of channel catfish with extracellular products of Aeromonas hydrophila provides protection against infection by the pathogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aeromonas hydrophila, a Gram-negative bacterium, is one of the economically-important pathogens in modern aquaculture. Among various traits, extracellular products (ECP) secreted by the bacterium are considered to be essential factors for virulence. Whether vaccination with the ECP could produce imm...

  17. Extracellular production of Streptomyces lividans acetyl xylan esterase A in Escherichia coli for rapid detection of activity.

    PubMed

    Nisole, Audrey; Lussier, François-Xavier; Morley, Krista L; Shareck, François; Kazlauskas, Romas J; Dupont, Claude; Pelletier, Joelle N

    2006-04-01

    Acetyl xylan esterase A (AxeA) from Streptomyces lividans belongs to a large family of industrially relevant polysaccharide esterases. AxeA and its truncated form containing only the catalytically competent domain, AxeA(tr), catalyze both the deacetylation of xylan and the N-deacetylation of chitosan. This broad substrate specificity lends additional interest to their characterization and production. Here, we report three systems for extracellular production of AxeA(tr): secretion from the native host S. lividans with the native signal peptide, extracellular production in Escherichia coli with the native signal peptide, and in E. coli with the OmpA signal peptide. Over five to seven days of a shake flask culture, the native host S. lividans with the native signal peptide secreted AxeA(tr) into the extracellular medium in high yield (388 mg/L) with specific activity of 19 U/mg corresponding to a total of 7000 U/L. Over one day of shake flask culture, E. coli with the native secretion signal peptide produced 84-fold less in the extracellular medium (4.6 mg/L), but the specific activity was higher (100 U/mg) corresponding to a total of 460 U/L. A similar E. coli culture using the OmpA signal peptide, produced 10mg/L with a specific activity of 68 U/mg, corresponding to a total of 680 U/L. In 96-well microtiter plates, extracellular production with E. coli gave approximately 30 and approximately 86 microg/mL in S. lividans. Expression in S. lividans with the native signal peptide is best for high level production, while expression in E. coli using the OmpA secretion signal peptide is best for high-throughput expression and screening of variants in microtiter plate format.

  18. Constitutive Extracellular Polysaccharide (EPS) Production by Specific Isolates of Crocosphaera watsonii

    PubMed Central

    Sohm, Jill A.; Edwards, Bethanie R.; Wilson, Brian G.; Webb, Eric A.

    2011-01-01

    Unicellular dinitrogen (N2) fixing cyanobacteria have only recently been identified in the ocean and recognized as important contributors to global N2 fixation. The only cultivated representatives of the open ocean unicellular diazotrophs are multiple isolates of Crocosphaera watsonii. Although constituents of the genus are nearly genetically identical, isolates have been described in two size classes, large ∼5 μm and small ∼3 μm cell diameters. We show here that the large size class constitutively produces substantial amounts of extracellular polysaccharides (EPS) during exponential growth, up to 10 times more than is seen in the small size class, and does so under both N2 fixing and non-N2 fixing conditions. The EPS production exceeds the amount produced by larger phytoplankton such as diatoms and coccolithophores by one to two orders of magnitude, is ∼22% of the total particulate organic C in the culture, and is depleted in N compared to cellular material. The large difference in observed EPS production may be accounted for by consistently higher photochemical efficiency of photosystem II in the large (0.5) vs. small (∼0.35) strains. While it is known that Crocosphaera plays an important role in driving the biological carbon (C) pump through the input of new nitrogen (N) to the open ocean, we hypothesize that this species may also contribute directly to the C cycle through the constitutive production of EPS. Indeed, at two stations in the North Pacific Subtropical Gyre, ∼70% of large Crocosphaera cells observed were embedded in EPS. The evolutionary advantage of releasing such large amounts of fixed C is still unknown, but in regions where Crocosphaera can be abundant (i.e., the warm oligotrophic ocean) this material will likely have important biogeochemical consequences. PMID:22110469

  19. Cultural conditions on the production of extracellular enzymes by Trichoderma isolates from tobacco rhizosphere.

    PubMed

    Mallikharjuna Rao, K L N; Siva Raju, K; Ravisankar, H

    2016-01-01

    Twelve isolates of Trichoderma spp. isolated from tobacco rhizosphere were evaluated for their ability to produce chitinase and β-1,3-glucanase extracellular hydrolytic enzymes. Isolates ThJt1 and TvHt2, out of 12 isolates, produced maximum activities of chitinase and β-1,3-glucanase, respectively. In vitro production of chitinase and β-1,3-glucanase by isolates ThJt1 and TvHt2 was tested under different cultural conditions. The enzyme activities were significantly influenced by acidic pH and the optimum temperature was 30°C. The chitin and cell walls of Sclerotium rolfsii, as carbon sources, supported the maximum and significantly higher chitinase activity by both isolates. The chitinase activity of isolate ThJt1 was suppressed significantly by fructose (80.28%), followed by glucose (77.42%), whereas the β-1,3-glucanase activity of ThJt1 and both enzymes of isolate TvHt2 were significantly suppressed by fructose, followed by sucrose. Ammonium nitrate as nitrogen source supported the maximum activity of chitinase in both isolates, whereas urea was a poor nitrogen source. Production of both enzymes by the isolates was significantly influenced by the cultural conditions. Thus, the isolates ThJt1 and TvHt2 showed higher levels of chitinase and β-1,3-glucanase activities and were capable of hydrolyzing the mycelium of S. rolfsii infecting tobacco. These organisms can be used therefore for assessment of their synergism in biomass production and biocontrol efficacy and for their field biocontrol ability against S. rolfsii and Pythium aphanidermatum infecting tobacco.

  20. Cultural conditions on the production of extracellular enzymes by Trichoderma isolates from tobacco rhizosphere

    PubMed Central

    Mallikharjuna Rao, K.L.N.; Siva Raju, K.; Ravisankar, H.

    2016-01-01

    Twelve isolates of Trichoderma spp. isolated from tobacco rhizosphere were evaluated for their ability to produce chitinase and β-1,3-glucanase extracellular hydrolytic enzymes. Isolates ThJt1 and TvHt2, out of 12 isolates, produced maximum activities of chitinase and β-1,3-glucanase, respectively. In vitro production of chitinase and β-1,3-glucanase by isolates ThJt1 and TvHt2 was tested under different cultural conditions. The enzyme activities were significantly influenced by acidic pH and the optimum temperature was 30 °C. The chitin and cell walls of Sclerotium rolfsii, as carbon sources, supported the maximum and significantly higher chitinase activity by both isolates. The chitinase activity of isolate ThJt1 was suppressed significantly by fructose (80.28%), followed by glucose (77.42%), whereas the β-1,3-glucanase activity of ThJt1 and both enzymes of isolate TvHt2 were significantly suppressed by fructose, followed by sucrose. Ammonium nitrate as nitrogen source supported the maximum activity of chitinase in both isolates, whereas urea was a poor nitrogen source. Production of both enzymes by the isolates was significantly influenced by the cultural conditions. Thus, the isolates ThJt1 and TvHt2 showed higher levels of chitinase and β-1,3-glucanase activities and were capable of hydrolyzing the mycelium of S. rolfsii infecting tobacco. These organisms can be used therefore for assessment of their synergism in biomass production and biocontrol efficacy and for their field biocontrol ability against S. rolfsii and Pythium aphanidermatum infecting tobacco. PMID:26887223

  1. High-yield production of extracellular type-I cellulose by the cyanobacterium Synechococcus sp. PCC 7002.

    PubMed

    Zhao, Chi; Li, Zhongkui; Li, Tao; Zhang, Yingjiao; Bryant, Donald A; Zhao, Jindong

    2015-01-01

    Cellulose synthase, encoded by the cesA gene, is responsible for the synthesis of cellulose in nature. We show that the cell wall of the cyanobacterium Synechococcus sp. PCC 7002 naturally contains cellulose. Cellulose occurs as a possibly laminated layer between the inner and outer membrane, as well as being an important component of the extracellular glycocalyx in this cyanobacterium. Overexpression of six genes, cmc-ccp-cesAB-cesC-cesD-bgl, from Gluconacetobacter xylinus in Synechococcus sp. PCC 7002 resulted in very high-yield production of extracellular type-I cellulose. High-level cellulose production only occurred when the native cesA gene was inactivated and when cells were grown at low salinity. This system provides a method for the production of lignin-free cellulose from sunlight and CO2 for biofuel production and other biotechnological applications. PMID:27462405

  2. High-yield production of extracellular type-I cellulose by the cyanobacterium Synechococcus sp. PCC 7002.

    PubMed

    Zhao, Chi; Li, Zhongkui; Li, Tao; Zhang, Yingjiao; Bryant, Donald A; Zhao, Jindong

    2015-01-01

    Cellulose synthase, encoded by the cesA gene, is responsible for the synthesis of cellulose in nature. We show that the cell wall of the cyanobacterium Synechococcus sp. PCC 7002 naturally contains cellulose. Cellulose occurs as a possibly laminated layer between the inner and outer membrane, as well as being an important component of the extracellular glycocalyx in this cyanobacterium. Overexpression of six genes, cmc-ccp-cesAB-cesC-cesD-bgl, from Gluconacetobacter xylinus in Synechococcus sp. PCC 7002 resulted in very high-yield production of extracellular type-I cellulose. High-level cellulose production only occurred when the native cesA gene was inactivated and when cells were grown at low salinity. This system provides a method for the production of lignin-free cellulose from sunlight and CO2 for biofuel production and other biotechnological applications.

  3. High-yield production of extracellular type-I cellulose by the cyanobacterium Synechococcus sp. PCC 7002

    PubMed Central

    Zhao, Chi; Li, Zhongkui; Li, Tao; Zhang, Yingjiao; Bryant, Donald A; Zhao, Jindong

    2015-01-01

    Cellulose synthase, encoded by the cesA gene, is responsible for the synthesis of cellulose in nature. We show that the cell wall of the cyanobacterium Synechococcus sp. PCC 7002 naturally contains cellulose. Cellulose occurs as a possibly laminated layer between the inner and outer membrane, as well as being an important component of the extracellular glycocalyx in this cyanobacterium. Overexpression of six genes, cmc–ccp–cesAB–cesC–cesD–bgl, from Gluconacetobacter xylinus in Synechococcus sp. PCC 7002 resulted in very high-yield production of extracellular type-I cellulose. High-level cellulose production only occurred when the native cesA gene was inactivated and when cells were grown at low salinity. This system provides a method for the production of lignin-free cellulose from sunlight and CO2 for biofuel production and other biotechnological applications. PMID:27462405

  4. Algal biofuels: challenges and opportunities.

    PubMed

    Leite, Gustavo B; Abdelaziz, Ahmed E M; Hallenbeck, Patrick C

    2013-10-01

    Biodiesel production using microalgae is attractive in a number of respects. Here a number of pros and cons to using microalgae for biofuels production are reviewed. Algal cultivation can be carried out using non-arable land and non-potable water with simple nutrient supply. In addition, algal biomass productivities are much higher than those of vascular plants and the extractable content of lipids that can be usefully converted to biodiesel, triacylglycerols (TAGs) can be much higher than that of the oil seeds now used for first generation biodiesel. On the other hand, practical, cost-effective production of biofuels from microalgae requires that a number of obstacles be overcome. These include the development of low-cost, effective growth systems, efficient and energy saving harvesting techniques, and methods for oil extraction and conversion that are environmentally benign and cost-effective. Promising recent advances in these areas are highlighted.

  5. Fractionation and characterization of the immunosuppressive substance in crude extracellular products released by Streptococcus intermedius.

    PubMed Central

    Arala-Chaves, M P; Porto, M T; Arnaud, P; Saraiva, M J; Geada, H; Patrick, C C; Fudenberg, H H

    1981-01-01

    The noncytotoxic immunosuppressive substance detected in crude extracellular products of Streptococcus intermedius (CEP-SI) was fractionated by two steps of preparative isoelectric focusing in sucrose gradients using ampholytes of pH range from 3.5 to 6 and 4 to 5, respectively. The in vitro and in vivo suppressor effects of the most highly purified fraction of CEP-Si, designated fraction 3' (F3'EP-Si), corresponded well with those of the original CEP-Si. F3'EP-Si was sensitive to the effects of alpha, gamma, and delta chymotrypsin, trypsin, and heating. It contained approximately 1% of the total amount of protein found in the original CEP-Si, corresponding to a single band on analytical isoelectric focusing, stainable by Coomassie Blue and of isoelectric point of 4.25. The absorption spectrum of F3'EP-Si had a maximum at 260 nm but its biological activity was resistant to deoxyribonuclease and ribonuclease A and it did not contain material stainable by methylene blue. It was also resistant to neuraminidase and did not contain material stainable by periodic acid schiff. We conclude that the substance responsible for the suppressor activity of CEP-Si is a protein of molecular weight approximately 90,000, which adheres to Sephadex of cellulose acetate and forms complexes with other, nonactive constituents of CEP-Si. Images PMID:6454698

  6. Bioremediation of Direct Blue 14 and Extracellular Ligninolytic Enzyme Production by White Rot Fungi: Pleurotus Spp.

    PubMed Central

    Singh, M. P.; Vishwakarma, S. K.; Srivastava, A. K.

    2013-01-01

    In the present investigation, four species of white rot fungi (Pleurotus), that is, P. flabellatus, P. florida, P. ostreatus and P. sajor-caju were used for decolorization of direct blue 14 (DB14). Among all four species of Pleurotus, P. flabellatus showed the fastest decolorization in petri plates on different concentration, that is, 200 mg/L, 400 mg/L, and 600 mg/L. All these four species were also evaluated for extracellular ligninolytic enzymes (laccase and manganese peroxidase) production and it was observed that the twelve days old culture of P. flabellatus showed the maximum enzymatic activity, that is, 915.7 U/mL and 769.2 U/mL of laccase and manganese peroxidase, respectively. Other three Pleurotus species took more time for dye decolorization and exhibited less enzymatic activities. The rate of decolorization of DB14 dye solution (20 mg/L) by crude enzymes isolated from P. flabellatus was very fast, and it was observed that up to 90.39% dye solution was decolorized in 6 hrs of incubation. PMID:23841054

  7. Lipolytic Potential of Aspergillus japonicus LAB01: Production, Partial Purification, and Characterisation of an Extracellular Lipase

    PubMed Central

    Souza, Lívia Tereza Andrade; Oliveira, Jamil S.; dos Santos, Vera L.; Regis, Wiliam C. B.; Santoro, Marcelo M.; Resende, Rodrigo R.

    2014-01-01

    Lipolytic potential of Aspergillus japonicus LAB01 was investigated by describing the catalytic properties and stability of a secreted extracellular lipase. Enzyme production was considered high under room temperature after 4 days using sunflower oil and a combination of casein with sodium nitrate. Lipase was partially purified by 3.9-fold, resulting in a 44.2% yield using ammonium sulphate precipitation (60%) quantified with Superose 12 HR gel filtration chromatography. The activity of the enzyme was maximised at pH 8.5, and the enzyme demonstrated stability under alkaline conditions. The optimum temperature was found to be 45°C, and the enzyme was stable for up to 100 minutes, with more than 80% of initial activity remaining after incubation at this temperature. Partially purified enzyme showed reasonable stability with triton X-100 and was activated in the presence of organic solvents (toluene, hexane, and methanol). Among the tested ions, only Cu2+, Ni2+, and Al3+ showed inhibitory effects. Substrate specificity of the lipase was higher for C14 among various p-nitrophenyl esters assayed. The KM and Vmax values of the purified enzyme for p-nitrophenyl palmitate were 0.13 mM and 12.58 umol/(L·min), respectively. These features render a novel biocatalyst for industrial applications. PMID:25530954

  8. Lipolytic potential of Aspergillus japonicus LAB01: production, partial purification, and characterisation of an extracellular lipase.

    PubMed

    Souza, Lívia Tereza Andrade; Oliveira, Jamil S; dos Santos, Vera L; Regis, Wiliam C B; Santoro, Marcelo M; Resende, Rodrigo R

    2014-01-01

    Lipolytic potential of Aspergillus japonicus LAB01 was investigated by describing the catalytic properties and stability of a secreted extracellular lipase. Enzyme production was considered high under room temperature after 4 days using sunflower oil and a combination of casein with sodium nitrate. Lipase was partially purified by 3.9-fold, resulting in a 44.2% yield using ammonium sulphate precipitation (60%) quantified with Superose 12 HR gel filtration chromatography. The activity of the enzyme was maximised at pH 8.5, and the enzyme demonstrated stability under alkaline conditions. The optimum temperature was found to be 45°C, and the enzyme was stable for up to 100 minutes, with more than 80% of initial activity remaining after incubation at this temperature. Partially purified enzyme showed reasonable stability with triton X-100 and was activated in the presence of organic solvents (toluene, hexane, and methanol). Among the tested ions, only Cu(2+), Ni(2+), and Al(3+) showed inhibitory effects. Substrate specificity of the lipase was higher for C14 among various p-nitrophenyl esters assayed. The KM and V max values of the purified enzyme for p-nitrophenyl palmitate were 0.13 mM and 12.58 umol/(L·min), respectively. These features render a novel biocatalyst for industrial applications.

  9. Virulence determinants and production of extracellular enzymes in Enterococcus spp. from surface water sources.

    PubMed

    Molale, Lesego Gertrude; Bezuidenhout, Cornelius Carlos

    2016-01-01

    Virulence factors in Enterococcus may be indicative of potential pathogenicity. The aim of this study was to determine the relationship between the presence of clinically relevant virulence genes, in Enterococcus spp. from environmental water, and their in vitro expression. One hundred and twenty-four Enterococcus isolates (seven species), from five surface water systems in the North West Province, South Africa, were screened for the presence of asa1, cylA, esp, gelE and hyl using polymerase chain reaction. The expression of cylA, hyl and gelE was determined by phenotypic assessments. Sixty-five percent of the isolates were positive for one virulence gene and 13% for two or more. Most frequently detected genes were gelE (32%) and cylA (28%). Enterococcal surface protein was absent in all isolates screened. The presence of virulence genes was correlated with their extracellular enzyme production. The results show that a large percentage of these environmental Enterococcus spp. possess virulence factors that could be expressed in vitro. This is a cause for concern and could have implications for individuals using this water for recreational and cultural purposes. Further investigation is required into the sources of these potential pathogenic Enterococcus isolates and measures to minimize their presence in water sources.

  10. A process for extracellular thermostable lipase production by a novel Bacillus thermoamylovorans strain.

    PubMed

    Deive, Francisco J; Álvarez, María S; Morán, Paloma; Sanromán, M Angeles; Longo, María A

    2012-08-01

    A lipolytic enzyme-producing thermophilic microorganism, recently isolated from a hot spring in Galicia (North Western Spain), has been investigated. First, the strain was genetically identified and tentatively named Bacillus thermoamylovorans CH6B. It produced significant levels (around 450 U/L) of extracellular lipolytic activity in shake flask cultures, and the most suitable conditions for this biological process were found at temperatures between 50 and 55 °C, and an initial pH value around 7.0. Next, a preliminary scaling up of the process was carried out in a 5-L stirred tank bioreactor, and it was concluded that operation at agitation and aeration rates of 300 rpm and 0.33 vvm, respectively, were advisable. In both type of cultures, the results were successfully fitted to logistic equations, and the relationship between lipase production and cell growth was investigated. Furthermore, some relevant properties of the crude lipolytic enzyme extracts were assessed. The crude biocatalyst preferentially hydrolysed p-nitrophenyl esters of medium and long-chain fatty acids. Thermal stability in aqueous solution of the produced enzyme was also promising, and the deactivation profiles were fitted to a series-type deactivation model. PMID:22237683

  11. Role of extracellular polymeric substances (EPS) production in bioaggregation: application to wastewater treatment.

    PubMed

    Ding, Zhiji; Bourven, Isabelle; Guibaud, Gilles; van Hullebusch, Eric D; Panico, Antonio; Pirozzi, Francesco; Esposito, Giovanni

    2015-12-01

    This paper reviews the formation, structure, and stability of bioaggregates with an emphasis on the composition and distribution of extracellular polymeric substances (EPS) and their role in bioaggregation. Bioaggregation is ubiquitous in natural environment and is of great importance in biological wastewater treatment processes. It greatly influences the flocculability, settleability, and dewaterability for flocs and sludge retention and shear resistance for biofilms. The physico-chemical and microbial structures of bioaggregates are dependent on operational conditions as well as microbial diversity and spatial distribution. The formation of bioaggregates is mediated by the physico-chemical interactions as well as the microbial interactions such as EPS production and quorum sensing. EPS are composed of a mixture of macromolecules including proteins, polysaccharides, humic-like substances, and nucleic acids, which entrap the microbial cells in a three-dimensional matrix. The composition and physico-chemical characteristics of EPS have significant influence on the maintenance of the bioaggregate structure and the process performance of the wastewater treatment. However, the mechanisms of bioaggregation are still unclear and the conclusions on the role of EPS were mostly drawn from the established correlations and hypotheses. This paper expects to provide up-to-date knowledge on bioaggregation and insights for further studies and applications. PMID:26381665

  12. Peptidylarginine Deiminase Inhibitor Suppresses Neutrophil Extracellular Trap Formation and MPO-ANCA Production

    PubMed Central

    Kusunoki, Yoshihiro; Nakazawa, Daigo; Shida, Haruki; Hattanda, Fumihiko; Miyoshi, Arina; Masuda, Sakiko; Nishio, Saori; Tomaru, Utano; Atsumi, Tatsuya; Ishizu, Akihiro

    2016-01-01

    Myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis is a systemic small-vessel vasculitis, wherein, MPO-ANCA plays a critical role in the pathogenesis. Neutrophil extracellular traps (NETs) released from activated neutrophils are composed of extracellular web-like DNA and antimicrobial proteins, including MPO. Diverse stimuli, such as phorbol myristate acetate (PMA) and ligands of toll-like receptors (TLR), induce NETs. Although TLR-mediated NET formation can occur with preservation of living neutrophilic functions (called vital NETosis), PMA-stimulated neutrophils undergo cell death with NET formation (called suicidal NETosis). In the process of suicidal NETosis, histones are citrullinated by peptidylarginine deiminase 4 (PAD4). Since this step is necessary for decondensation of DNA, PAD4 plays a pivotal role in suicidal NETosis. Although NETs are essential for elimination of microorganisms, excessive formation of NETs has been suggested to be implicated in MPO-ANCA production. This study aimed to determine if pan-PAD inhibitors could suppress MPO-ANCA production in vivo. At first, NETs were induced in peripheral blood neutrophils derived from healthy donors (1 × 106/ml) by stimulation with 20 nM PMA with or without 20 μM propylthiouracil (PTU), an anti-thyroid drug. We then determined that the in vitro NET formation was inhibited completely by 200 μM Cl-amidine, a pan-PAD inhibitor. Next, we established mouse models with MPO-ANCA production. BALB/c mice were given intraperitoneal (i.p.) injection of PMA (50 ng at days 0 and 7) and oral PTU (2.5 mg/day) for 2 weeks. These mice were divided into two groups; the first group was given daily i.p. injection of PBS (200 μl/day) (n = 13) and the other group with daily i.p. injection of Cl-amidine (0.3 mg/200 μl PBS/day) (n = 7). Two weeks later, citrullination as an indicator of NET formation in the peritoneum and serum MPO-ANCA titer was compared

  13. A GIS cost model to assess the availability of freshwater, seawater, and saline groundwater for algal biofuel production in the United States.

    PubMed

    Venteris, Erik R; Skaggs, Richard L; Coleman, Andre M; Wigmosta, Mark S

    2013-05-01

    A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a partial techno-economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply (constrained to less than 5% of mean annual flow per watershed) and costs, and cost-distance models for supplying seawater and saline groundwater. We estimate that, combined, these resources can support 9.46 × 10(7) m(3) yr(-1) (25 billion gallons yr(-1)) of renewable biodiesel production in the coterminous United States. Achievement of larger targets requires the utilization of less water efficient sites and relatively expensive saline waters. Despite the addition of freshwater supply constraints and saline water resources, the geographic conclusions are similar to our previous results. Freshwater availability and saline water delivery costs are most favorable for the coast of the Gulf of Mexico and Florida peninsula, where evaporation relative to precipitation is moderate. As a whole, the barren and scrub lands of the southwestern U.S. have limited freshwater supplies, and large net evaporation rates greatly increase the cost of saline alternatives due to the added makeup water required to maintain pond salinity. However, this and similar analyses are particularly sensitive to knowledge gaps in algae growth/lipid production performance and the proportion of freshwater resources available, key topics for future investigation. PMID:23495893

  14. A GIS cost model to assess the availability of freshwater, seawater, and saline groundwater for algal biofuel production in the United States.

    PubMed

    Venteris, Erik R; Skaggs, Richard L; Coleman, Andre M; Wigmosta, Mark S

    2013-05-01

    A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a partial techno-economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply (constrained to less than 5% of mean annual flow per watershed) and costs, and cost-distance models for supplying seawater and saline groundwater. We estimate that, combined, these resources can support 9.46 × 10(7) m(3) yr(-1) (25 billion gallons yr(-1)) of renewable biodiesel production in the coterminous United States. Achievement of larger targets requires the utilization of less water efficient sites and relatively expensive saline waters. Despite the addition of freshwater supply constraints and saline water resources, the geographic conclusions are similar to our previous results. Freshwater availability and saline water delivery costs are most favorable for the coast of the Gulf of Mexico and Florida peninsula, where evaporation relative to precipitation is moderate. As a whole, the barren and scrub lands of the southwestern U.S. have limited freshwater supplies, and large net evaporation rates greatly increase the cost of saline alternatives due to the added makeup water required to maintain pond salinity. However, this and similar analyses are particularly sensitive to knowledge gaps in algae growth/lipid production performance and the proportion of freshwater resources available, key topics for future investigation.

  15. Effects of fish density and river fertilization on algal standing stocks, invertebrates communities, and fish production in an Arctic River

    USGS Publications Warehouse

    Deegan, Linda A.; Peterson, B.J.; Golden, H.; McIvor, C.C.; Miller, M.C.

    1997-01-01

    This study examined the relative importance of bottom-up and top-down controls of an arctic stream food web by simultaneous manipulation of the top predator and nutrient availability. We created a two-step trophic system (algae to insects) by removal of the top predator (Arctic grayling, Thymallus arcticus) in fertilized and control stream reaches. Fish abundance was also increased 10 times to examine the effect of high fish density on stream ecosystem dynamics and fish. We measured the response of epilithic algae, benthic and drifting insects, and fish to nutrient enrichment and to changes in fish density. Insect grazers had little effect on algae and fish had little effect on insects. In both the control and fertilized reaches, fish growth, energy storage, and reproductive response of females declined with increased fish density. Fish growth and energy storage were more closely correlated with per capita insect availability than with per capita algal standing stock

  16. Highly virulent strains of Pseudomonas solanacearum that are defective in extracellular-polysaccharide production.

    PubMed Central

    Xu, P L; Iwata, M; Leong, S; Sequeira, L

    1990-01-01

    Extracellular polysaccharide (EPS) has long been regarded as one of the most important factors involved in wilting of plants by Pseudomonas solanacearum. By means of transposon Tn5 mutagenesis, we have isolated a class of mutants that have an afluidal colony morphology but retain the ability to cause severe wilting and death of tobacco plants. One such mutant, KD700, was studied in detail. By marker exchange mutagenesis, the altered colony morphology was shown to be the result of a single Tn5 insertion in a 14.3-kilobase EcoRI fragment. This defect could be corrected by introducing a homologous clone from a cosmid library of the wild-type, parental strain K60. The Tn5-containing fragment was introduced into other P. solanacearum wild-type strains by marker exchange, and these altered strains had the same afluidal phenotype as KD700. N-Acetylgalactosamine (GalNac), the major constituent of EPS of all wild-type strains of P. solanacearum, was not detected by gas chromatography-mass spectrometry analysis of vascular fluids from wilting plants infected by KD700. In contrast, GalNac was readily detected in similar fluids of plants infected by K60. Polysaccharides extracted from culture filtrates of KD700 contained approximately one-fifth of the GalNac present in polysaccharides from K60. No differences in growth rates in culture or in planta between the mutant and the parental strains were observed. Since strains that are deficient in EPS production can remain highly virulent to tobacco, we conclude that EPS, or at least its GalNac-containing component, may not be required for disease development by P. solanacearum. Images PMID:2163393

  17. Experimental investigation and optimization of process variables affecting the production of extracellular lipase by Kluyveromyces marxianus IFO 0288.

    PubMed

    Stergiou, Panagiota-Yiolanda; Foukis, Athanasios; Sklivaniti, Helen; Zacharaki, Paraskevi; Papagianni, Maria; Papamichael, Emmanuel M

    2012-10-01

    In this study, the production and optimization of extracellular lipase from Kluyveromyces marxianus IFO 0288 was investigated by using optimized nutritional and cultural conditions in a yeast medium containing glucose as the carbon source in fully aerobic batch fermentation (150 rpm). The influence of four fermentation parameters (type of lipidic source, initial culture pH, temperature, and length of fermentation) on growth and lipase production was investigated and evaluated using the conventional "one variable at a time" approach and response surface methodology. An 18-fold increase in lipase production during 65 h of fermentation was obtained with optimized nutritional (0.5 % olive oil) and cultivation (pH 6.5, 35 °C) conditions by employing the conventional optimization method. By applying the response surface methodology technique the initial pH value of 6.4 and temperature of 32.5 °C were identified as optimal and led to further improvements (up to 18-fold) of extracellular lipase production. The results provide, for the first time, evidence that K. marxianus has the potential to be used as an efficient producer of extracellular lipase with prospective application in a variety of industrial and biotechnological areas.

  18. Extracellular heat shock protein 90 binding to TGFβ receptor I participates in TGFβ-mediated collagen production in myocardial fibroblasts.

    PubMed

    García, Raquel; Merino, David; Gómez, Jenny M; Nistal, J Francisco; Hurlé, María A; Cortajarena, Aitziber L; Villar, Ana V

    2016-10-01

    The pathological remodeling heart shows an increase in left ventricular mass and an excess of extracellular matrix deposition that can over time cause heart failure. Transforming growth factor β (TGFβ) is the main cytokine controlling this process. The molecular chaperone heat shock protein 90 (Hsp90) has been shown to play a critical role in TGFβ signaling by stabilizing the TGFβ signaling cascade. We detected extracellular Hsp90 in complex with TGFβ receptor I (TGFβRI) in fibroblasts and determined a close proximity between both proteins suggesting a potential physical interaction between the two at the plasma membrane. This was supported by in silico studies predicting Hsp90 dimers and TGFβRI extracellular domain interaction. Both, Hsp90aa1 and Hsp90ab1 isoforms participate in TGFβRI complex. Extracellular Hsp90 inhibition lessened the yield of collagen production as well as the canonical TGFβ signaling cascade, and collagen protein synthesis was drastically reduced in Hsp90aa1 KO mice. These observations together with the significant increase in activity of Hsp90 at the plasma membrane pointed to a functional cooperative partnership between Hsp90 and TGFβRI in the fibrotic process. We propose that a surface population of Hsp90 extracellularly binds TGFβRI and this complex behaves as an active participant in collagen production in TGFβ-activated fibroblasts. We also offer an in vivo insight into the role of Hsp90 and its isoforms during cardiac remodeling in murine aortic banding model suffering from pathological cardiac remodeling and detect circulating Hsp90 overexpressed in remodeling mice.

  19. Extracellular Histones Induce Chemokine Production in Whole Blood Ex Vivo and Leukocyte Recruitment In Vivo

    PubMed Central

    Westman, Johannes; Papareddy, Praveen; Dahlgren, Madelene W.; Chakrakodi, Bhavya; Norrby-Teglund, Anna; Smeds, Emanuel; Linder, Adam; Mörgelin, Matthias; Johansson-Lindbom, Bengt; Egesten, Arne; Herwald, Heiko

    2015-01-01

    The innate immune system relies to a great deal on the interaction of pattern recognition receptors with pathogen- or damage-associated molecular pattern molecules. Extracellular histones belong to the latter group and their release has been described to contribute to the induction of systemic inflammatory reactions. However, little is known about their functions in the early immune response to an invading pathogen. Here we show that extracellular histones specifically target monocytes in human blood and this evokes the mobilization of the chemotactic chemokines CXCL9 and CXCL10 from these cells. The chemokine induction involves the toll-like receptor 4/myeloid differentiation factor 2 complex on monocytes, and is under the control of interferon-γ. Consequently, subcutaneous challenge with extracellular histones results in elevated levels of CXCL10 in a murine air pouch model and an influx of leukocytes to the site of injection in a TLR4 dependent manner. When analyzing tissue biopsies from patients with necrotizing fasciitis caused by Streptococcus pyogenes, extracellular histone H4 and CXCL10 are immunostained in necrotic, but not healthy tissue. Collectively, these results show for the first time that extracellular histones have an important function as chemoattractants as their local release triggers the recruitment of immune cells to the site of infection. PMID:26646682

  20. Macromolecularly crowded in vitro microenvironments accelerate the production of extracellular matrix-rich supramolecular assemblies

    PubMed Central

    Kumar, Pramod; Satyam, Abhigyan; Fan, Xingliang; Collin, Estelle; Rochev, Yury; Rodriguez, Brian J.; Gorelov, Alexander; Dillon, Simon; Joshi, Lokesh; Raghunath, Michael; Pandit, Abhay; Zeugolis, Dimitrios I.

    2015-01-01

    Therapeutic strategies based on the principles of tissue engineering by self-assembly put forward the notion that functional regeneration can be achieved by utilising the inherent capacity of cells to create highly sophisticated supramolecular assemblies. However, in dilute ex vivo microenvironments, prolonged culture time is required to develop an extracellular matrix-rich implantable device. Herein, we assessed the influence of macromolecular crowding, a biophysical phenomenon that regulates intra- and extra-cellular activities in multicellular organisms, in human corneal fibroblast culture. In the presence of macromolecules, abundant extracellular matrix deposition was evidenced as fast as 48 h in culture, even at low serum concentration. Temperature responsive copolymers allowed the detachment of dense and cohesive supramolecularly assembled living substitutes within 6 days in culture. Morphological, histological, gene and protein analysis assays demonstrated maintenance of tissue-specific function. Macromolecular crowding opens new avenues for a more rational design in engineering of clinically relevant tissue modules in vitro. PMID:25736020

  1. Alkaline Phosphatase, Soluble Extracellular Adenine Nucleotides, and Adenosine Production after Infant Cardiopulmonary Bypass

    PubMed Central

    Davidson, Jesse A.; Urban, Tracy; Tong, Suhong; Twite, Mark; Woodruff, Alan

    2016-01-01

    Rationale Decreased alkaline phosphatase activity after infant cardiac surgery is associated with increased post-operative cardiovascular support requirements. In adults undergoing coronary artery bypass grafting, alkaline phosphatase infusion may reduce inflammation. Mechanisms underlying these effects have not been explored but may include decreased conversion of extracellular adenine nucleotides to adenosine. Objectives 1) Evaluate the association between alkaline phosphatase activity and serum conversion of adenosine monophosphate to adenosine after infant cardiac surgery; 2) assess if inhibition/supplementation of serum alkaline phosphatase modulates this conversion. Methods and Research Pre/post-bypass serum samples were obtained from 75 infants <4 months of age. Serum conversion of 13C5-adenosine monophosphate to 13C5-adenosine was assessed with/without selective inhibition of alkaline phosphatase and CD73. Low and high concentration 13C5-adenosine monophosphate (simulating normal/stress concentrations) were used. Effects of alkaline phosphatase supplementation on adenosine monophosphate clearance were also assessed. Changes in serum alkaline phosphatase activity were strongly correlated with changes in 13C5-adenosine production with or without CD73 inhibition (r = 0.83; p<0.0001). Serum with low alkaline phosphatase activity (≤80 U/L) generated significantly less 13C5-adenosine, particularly in the presence of high concentration 13C5-adenosine monophosphate (10.4μmol/L vs 12.9μmol/L; p = 0.0004). Inhibition of alkaline phosphatase led to a marked decrease in 13C5-adenosine production (11.9μmol/L vs 2.7μmol/L; p<0.0001). Supplementation with physiologic dose human tissue non-specific alkaline phosphatase or high dose bovine intestinal alkaline phosphatase doubled 13C5-adenosine monophosphate conversion to 13C5-adenosine (p<0.0001). Conclusions Alkaline phosphatase represents the primary serum ectonucleotidase after infant cardiac surgery and low post

  2. Algal Supply System Design - Harmonized Version

    SciTech Connect

    Abodeely, Jared; Stevens, Daniel; Ray, Allison; Newby, Deborah; Schaller, Kastli

    2013-03-01

    The objective of this design report is to provide an assessment of current technologies used for production, dewatering, and converting microalgae cultivated in open-pond systems to biofuel. The original draft design was created in 2011 and has subsequently been brought into agreement with the DOE harmonized model. The design report extends beyond this harmonized model to discuss some of the challenges with assessing algal production systems, including the ability to (1) quickly assess alternative algal production system designs, (2) assess spatial and temporal variability, and (3) perform large-scale assessments considering multiple scenarios for thousands of potential sites. The Algae Logistics Model (ALM) was developed to address each of these limitations of current modeling efforts to enable assessment of the economic feasibility of algal production systems across the United States. The (ALM) enables (1) dynamic assessments using spatiotemporal conditions, (2) exploration of algal production system design configurations, (3) investigation of algal production system operating assumptions, and (4) trade-off assessments with technology decisions and operating assumptions. The report discusses results from the ALM, which is used to assess the baseline design determined by harmonization efforts between U.S. DOE national laboratories. Productivity and resource assessment data is provided by coupling the ALM with the Biomass Assessment Tool developed at PNNL. This high-fidelity data is dynamically passed to the ALM and used to help better understand the impacts of spatial and temporal constraints on algal production systems by providing a cost for producing extracted algal lipids annually for each potential site.

  3. Evaluation of the integrated hydrothermal carbonization-algal cultivation process for enhanced nitrogen utilization in Arthrospira platensis production.

    PubMed

    Yao, Changhong; Wu, Peichun; Pan, Yanfei; Lu, Hongbin; Chi, Lei; Meng, Yingying; Cao, Xupeng; Xue, Song; Yang, Xiaoyi

    2016-09-01

    Sustainable microalgal cultivation at commercial scale requires nitrogen recycling. This study applied hydrothermal carbonization to recover N of hot-water extracted Arthrospira platensis biomass residue into aqueous phase (AP) under different operation conditions and evaluated the N utilization, biomass yield and quality of A. platensis cultures using AP as the sole N source. With the increase of temperature at 190-210°C or reaction time of 2-3h, the N recovery rate decreased under nitrogen-repletion (+N) cultivation, while contrarily increased under nitrogen-limitation (-N) cultivation. Under +N biomass accumulation in the cultures with AP under 190°C was enhanced by 41-67% compared with that in NaNO3, and the highest protein content of 51.5%DW achieved under 200°C-2h was also 22% higher. Carbohydrate content of 71.4%DW under -N cultivation achieved under 210°C-3h was 14% higher than that in NaNO3. HTC-algal cultivation strategy under -N mode could save 60% of conventional N. PMID:27262092

  4. Advances in time course extracellular production of human pre-miR-29b from Rhodovulum sulfidophilum.

    PubMed

    Pereira, Patrícia; Pedro, Augusto Q; Tomás, Joana; Maia, Cláudio J; Queiroz, João A; Figueiras, Ana; Sousa, Fani

    2016-04-01

    The present study reports the successful production of human pre-miR-29b both intra- and extracellularly in the marine phototrophic bacterium Rhodovulum sulfidophilum using recombinant RNA technology. In a first stage, the optimal transformation conditions (0.025 μg of plasmid DNA, with a heat-shock of 2 min at 35 °C) were established, in order to transfer the pre-miR-29b encoding plasmid to R. sulfidophilum host. Furthermore, the extracellular recovery of this RNA product from the culture medium was greatly improved, achieving quantities that are compatible with the majority of applications, namely for in vitro or in vivo studies. Using this system, the extracellular human pre-miR-29b concentration was approximately 182 μg/L, after 40 h of bacterial growth, and the total intracellular pre-miR-29b was of about 358 μg/L, at 32 h. At the end of the fermentation, it was verified that almost 87 % of cells were viable, indicating that cell lysis is minimized and that the extracellular medium is not highly contaminated with the host intracellular ribonucleases (RNases) and endotoxins, which is a critical parameter to guarantee the microRNA (miRNA) integrity. These findings demonstrate that pre-miRNAs can be produced by recombinant RNA technology, offering novel clues for the production of natural pre-miRNA agents for functional studies and RNA interference (RNAi)-based therapeutics. PMID:26860940

  5. Environmental performance of algal biofuel technology options.

    PubMed

    Vasudevan, Venkatesh; Stratton, Russell W; Pearlson, Matthew N; Jersey, Gilbert R; Beyene, Abraham G; Weissman, Joseph C; Rubino, Michele; Hileman, James I

    2012-02-21

    Considerable research and development is underway to produce fuels from microalgae, one of several options being explored for increasing transportation fuel supplies and mitigating greenhouse gas emissions (GHG). This work models life-cycle GHG and on-site freshwater consumption for algal biofuels over a wide technology space, spanning both near- and long-term options. The environmental performance of algal biofuel production can vary considerably and is influenced by engineering, biological, siting, and land-use considerations. We have examined these considerations for open pond systems, to identify variables that have a strong influence on GHG and freshwater consumption. We conclude that algal biofuels can yield GHG reductions relative to fossil and other biobased fuels with the use of appropriate technology options. Further, freshwater consumption for algal biofuels produced using saline pond systems can be comparable to that of petroleum-derived fuels. PMID:22324757

  6. Effect of light on growth, intracellular and extracellular pigment production by five pigment-producing filamentous fungi in synthetic medium.

    PubMed

    Velmurugan, Palanivel; Lee, Yong Hoon; Venil, Chidambaram Kulandaisamy; Lakshmanaperumalsamy, Perumalsamy; Chae, Jong-Chan; Oh, Byung-Taek

    2010-04-01

    The competence of the living creatures to sense and respond to light is well known. The effect of darkness and different color light quality on biomass, extracellular and intracellular pigment yield of five potent pigment producers Monascus purpureus, Isaria farinosa, Emericella nidulans, Fusarium verticillioides and Penicillium purpurogenum, with different color shades such as red, pink, reddish brown and yellow, were investigated. Incubation in total darkness increased the biomass, extracellular and intracellular pigment production in all the fungi. Extracellular red pigment produced by M. purpureus resulted maximum in darkness 36.75 + or - 2.1 OD and minimum in white unscreened light 5.90 + or - 1.1 OD. Similarly, intracellular red pigment produced by M. purpureus resulted maximum in darkness 18.27 + or - 0.9 OD/g and minimum in yellow light 8.03 + or - 0.6 OD/g of substrate. The maximum biomass production was also noticed in darkness 2.51 g/L and minimum in yellow light 0.5 g/L of dry weight. In contrast, growth of fungi in green and yellow wavelengths resulted in low biomass and pigment yield. It was found that darkness, (red 780-622 nm, blue 492-455 nm) and white light influenced pigment and biomass yield. PMID:20226375

  7. Application of repeated aspartate tags to improving extracellular production of Escherichia coli L-asparaginase isozyme II.

    PubMed

    Kim, Sun-Ki; Min, Won-Ki; Park, Yong-Cheol; Seo, Jin-Ho

    2015-11-01

    Asparaginase isozyme II from Escherichia coli is a popular enzyme that has been used as a therapeutic agent against acute lymphoblastic leukemia. Here, fusion tag systems consisting of the pelB signal sequence and various lengths of repeated aspartate tags were devised to highly express and to release active asparaginase isozyme II extracellularly in E. coli. Among several constructs, recombinant asparaginase isozyme II fused with the pelB signal sequence and five aspartate tag was secreted efficiently into culture medium at 34.6 U/mg cell of specific activity. By batch fermentation, recombinant E. coli produced 40.8 U/ml asparaginase isozyme II in the medium. In addition, deletion of the gspDE gene reduced extracellular production of asparaginase isozyme II, indicating that secretion of recombinant asparaginase isozyme II was partially ascribed to the recognition by the general secretion machinery. This tag system composed of the pelB signal peptide, and repeated aspartates can be applied to extracellular production of other recombinant proteins.

  8. Application of repeated aspartate tags to improving extracellular production of Escherichia coli L-asparaginase isozyme II.

    PubMed

    Kim, Sun-Ki; Min, Won-Ki; Park, Yong-Cheol; Seo, Jin-Ho

    2015-11-01

    Asparaginase isozyme II from Escherichia coli is a popular enzyme that has been used as a therapeutic agent against acute lymphoblastic leukemia. Here, fusion tag systems consisting of the pelB signal sequence and various lengths of repeated aspartate tags were devised to highly express and to release active asparaginase isozyme II extracellularly in E. coli. Among several constructs, recombinant asparaginase isozyme II fused with the pelB signal sequence and five aspartate tag was secreted efficiently into culture medium at 34.6 U/mg cell of specific activity. By batch fermentation, recombinant E. coli produced 40.8 U/ml asparaginase isozyme II in the medium. In addition, deletion of the gspDE gene reduced extracellular production of asparaginase isozyme II, indicating that secretion of recombinant asparaginase isozyme II was partially ascribed to the recognition by the general secretion machinery. This tag system composed of the pelB signal peptide, and repeated aspartates can be applied to extracellular production of other recombinant proteins. PMID:26320714

  9. Extracellular Polysaccharide Production in a Scytonemin-Deficient Mutant of Nostoc punctiforme Under UVA and Oxidative Stress.

    PubMed

    Soule, Tanya; Shipe, Dexter; Lothamer, Justin

    2016-10-01

    Some cyanobacteria can protect themselves from ultraviolet radiation by producing sunscreen pigments. In particular, the sheath pigment scytonemin protects cells against long-wavelength UVA radiation and is only found in cyanobacteria which are capable of extracellular polysaccharide (EPS) production. The presence of a putative glycosyltransferase encoded within the scytonemin gene cluster, along with the localization of scytonemin and EPS to the extracellular sheath, prompted us to investigate the relationship between scytonemin and EPS production under UVA stress. In this study, it was hypothesized that there would be a relationship between the biosynthesis of scytonemin and EPS under both UVA and oxidative stress, since the latter is a by-product of UVA radiation. EPS production was measured following exposure of wild-type Nostoc punctiforme and the non-scytonemin-producing strain SCY59 to UVA and oxidative stress. Under UVA, SCY59 produced significantly more EPS than the unstressed controls and the wild type, while both strains produced more EPS under oxidative stress compared to the controls. The results suggest that EPS secretion occurs in response to the oxidative stress by-product of UVA rather than as a direct response to UVA radiation. PMID:27301251

  10. Mechanism and challenges in commercialisation of algal biofuels.

    PubMed

    Singh, Anoop; Nigam, Poonam Singh; Murphy, Jerry D

    2011-01-01

    Biofuels made from algal biomass are being considered as the most suitable alternative energy in current global and economical scenario. Microalgae are known to produce and accumulate lipids within their cell mass which is similar to those found in many vegetable oils. The efficient lipid producer algae cell mass has been reported to contain more than 30% of their cell weight as lipids. According to US DOE microalgae have the potential to produce 100 times more oil per acre land than any terrestrial plants. This article reviews up to date literature on the composition of algae, mechanism of oil droplets, triacylglycerol (TAG) production in algal biomass, research and development made in the cultivation of algal biomass, harvesting strategies, and recovery of lipids from algal mass. The economical challenges in the production of biofuels from algal biomass have been discussed in view of the future prospects in the commercialisation of algal fuels.

  11. Hydrothermal liquefaction of harvested high-ash low-lipid algal biomass from Dianchi Lake: effects of operational parameters and relations of products.

    PubMed

    Tian, Chunyan; Liu, Zhidan; Zhang, Yuanhui; Li, Baoming; Cao, Wei; Lu, Haifeng; Duan, Na; Zhang, Li; Zhang, Tingting

    2015-05-01

    Hydrothermal liquefaction (HTL) allows a direct conversion of algal biomass into biocrude oil, not only solving the environmental issues caused by the over-growing algae but also producing renewable energy. This study reports HTL of algae after separation from eutrophicated Dianchi Lake in China. Conversion efficiency was studied under different operational conditions via an orthogonal design, including holding temperature (HT) (260-340 °C), retention time (RT) (30-90 min) and total solid (TS) (10-20%). A highest biocrude oil yield (18.4%, dry ash-free basis, daf) was achieved at 300 °C, 60 min, and 20% (TS), due to the low contents of lipids (1.9%, daf) and proteins (24.8%, daf), and high contents of ash (41.6%, dry basis) and carbohydrates (71.8%, daf). Operational parameters significantly affected the biocrude yields, and chemical distribution of HTL products. The biocrude production also related to other HTL products, and involved chemical reactions, such as deoxygenation and/or denitrogenation.

  12. An Assay to Quantify Chemotactic Properties of Degradation Products from Extracellular Matrix

    PubMed Central

    Sicari, Brian M.; Zhang, Li; Londono, Ricardo; Badylak, Stephen F.

    2015-01-01

    The endogenous chemotaxis of cells toward sites of tissue injury and/or biomaterial implantation is an important component of the host response. Implanted biomaterials capable of recruiting host stem/progenitor cells to a site of interest may obviate challenges associated with cell transplantation. An assay for the identification and quantification of chemotaxis induced by surgically placed biologic scaffolds composed of extracellular matrix is described herein. PMID:24155230

  13. Effects of two different nutrient loads on microalgal production, nutrient removal and photosynthetic efficiency in pilot-scale wastewater high rate algal ponds.

    PubMed

    Sutherland, Donna L; Turnbull, Matthew H; Broady, Paul A; Craggs, Rupert J

    2014-12-01

    When wastewater treatment high rate algal ponds (HRAP) are coupled with resource recovery processes, such as biofuel production, short hydraulic retention times (HRTs) are often favoured to increase the microalgal biomass productivity. However, short HRT can result in increased nutrient load to the HRAP which may negatively impact on the performance of the microalgae. This paper investigate the effects of high (NH4-N mean concentration 39.7 ± 17.9 g m(-3)) and moderate ((NH4-N mean concentration 19.9 ± 8.9 g m(-3)) nutrient loads and short HRT on the performance of microalgae with respect to light absorption, photosynthesis, biomass production and nutrient removal in pilot-scale (total volume 8 m(3)) wastewater treatment HRAPs. Microalgal biomass productivity was significantly higher under high nutrient loads, with a 133% and 126% increase in the chlorophyll-a and VSS areal productivities, respectively. Microalgae were more efficient at assimilating NH4-N from the wastewater under higher nutrient loads compared to moderate loads. Higher microalgal biomass with increased nutrient load resulted in increased light attenuation in the HRAP and lower light absorption efficiency by the microalgae. High nutrient loads also resulted in improved photosynthetic performance with significantly higher maximum rates of electron transport, oxygen production and quantum yield. This experiment demonstrated that microalgal productivity and nutrient removal efficiency were not inhibited by high nutrient loads, however, higher loads resulted in lower water quality in effluent discharge.

  14. Effects of two different nutrient loads on microalgal production, nutrient removal and photosynthetic efficiency in pilot-scale wastewater high rate algal ponds.

    PubMed

    Sutherland, Donna L; Turnbull, Matthew H; Broady, Paul A; Craggs, Rupert J

    2014-12-01

    When wastewater treatment high rate algal ponds (HRAP) are coupled with resource recovery processes, such as biofuel production, short hydraulic retention times (HRTs) are often favoured to increase the microalgal biomass productivity. However, short HRT can result in increased nutrient load to the HRAP which may negatively impact on the performance of the microalgae. This paper investigate the effects of high (NH4-N mean concentration 39.7 ± 17.9 g m(-3)) and moderate ((NH4-N mean concentration 19.9 ± 8.9 g m(-3)) nutrient loads and short HRT on the performance of microalgae with respect to light absorption, photosynthesis, biomass production and nutrient removal in pilot-scale (total volume 8 m(3)) wastewater treatment HRAPs. Microalgal biomass productivity was significantly higher under high nutrient loads, with a 133% and 126% increase in the chlorophyll-a and VSS areal productivities, respectively. Microalgae were more efficient at assimilating NH4-N from the wastewater under higher nutrient loads compared to moderate loads. Higher microalgal biomass with increased nutrient load resulted in increased light attenuation in the HRAP and lower light absorption efficiency by the microalgae. High nutrient loads also resulted in improved photosynthetic performance with significantly higher maximum rates of electron transport, oxygen production and quantum yield. This experiment demonstrated that microalgal productivity and nutrient removal efficiency were not inhibited by high nutrient loads, however, higher loads resulted in lower water quality in effluent discharge. PMID:25189477

  15. Harmful Algal Blooms (HABs)

    MedlinePlus

    ... Topics Eighth Annual National Conference on Health Communication, Marketing & Media August 19-21, 2014 Atlanta, GA Harmful Algal Blooms Recommend on Facebook Tweet Share Compartir On this Page What's the ...

  16. Proteolytic activity of extracellular products from Arthrobotrys musiformis and their effect in vitro against Haemonchus contortus infective larvae

    PubMed Central

    Acevedo-Ramírez, Perla María del Carmen; Figueroa-Castillo, Juan Antonio; Ulloa-Arvizú, Raúl; Martínez-García, Luz Gisela; Guevara-Flores, Alberto; Rendón, Juan Luis; Valero-Coss, Rosa Ofelia; Mendoza-de Gives, Pedro; Quiroz-Romero, Héctor

    2015-01-01

    Arthrobotrys musiformis is a nematophagous fungus with potential for the biological control of Haemonchus contortus larvae. This study aimed to identify and demonstrate the proteolytic activity of extracellular products from A musiformis cultured in a liquid medium against H contortus infective larvae. A musiformis was cultured on a solid medium and further grown in a liquid medium, which was then processed through ion exchange and hydrophobic interaction chromatography. The proteolytic activity of the purified fraction was assayed with either gelatin or bovine serum albumin as substrate. Optimum proteolytic activity was observed at pH 8 and a temperature of 37°C. Results obtained with specific inhibitors suggest the enzyme belongs to the serine-dependent protease family. The purified fraction concentrate from A musiformis was tested against H contortus infective larvae. A time-dependent effect was observed with 77 per cent immobility after 48 hours incubation, with alteration of the sheath. It is concluded that A musiformis is a potential candidate for biological control because of its resistant structures and also because of its excretion of extracellular products such as proteases. The present study contributes to the identification of one of the in vitro mechanisms of action of Amusiformis, namely the extracellular production of proteases against H contortus infective larvae. More investigations should be undertaken into how these products could be used to decrease the nematode population in sheep flocks under field conditions, thereby improving animal health while simultaneously diminishing the human and environmental impact of chemical-based drugs. PMID:26392902

  17. Development of a mixed mode adsorption process for the direct product sequestration of an extracellular protease from microbial batch cultures.

    PubMed

    Hamilton, G E; Luechau, F; Burton, S C; Lyddiatt, A

    2000-04-28

    Direct product sequestration of extracellular proteins from microbial batch cultures can be achieved by continuous or intermittent broth recycle through an external extractive loop. Here, we describe the development of a fluidisable, mixed mode adsorbent, designed to tolerate increasing ionic strength (synonymous with extended productive batch cultures). This facilitated operations for the integrated recovery of an extracellular acid protease from cultures of Yarrowia lipolytica. Mixed mode adsorbents were prepared using chemistries containing hydrophobic and ionic groups. Matrix hydrophobicity and titration ranges were matched to the requirements of integrated protease adsorption. A single expanded bed was able to service the productive phase of growth without recourse to the pH adjustment of the broth previously required for ion exchange adsorption. This resulted in increased yields of product, accompanied by further increases in enzyme specific activity. A step change from pH 4.5 to 2.6, across the isoelectric point of the protease, enabled high resolution fixed bed elution induced by electrostatic repulsion. The generic application of mixed mode chemistries, which combine the physical robustness of ion-exchange ligands in sanitisation and sterilisation procedures with a selectivity, which approaches that of affinity interactions, is discussed.

  18. Enhancement of a novel extracellular uricase production by media optimization and partial purification by aqueous three-phase system.

    PubMed

    Ram, Senthoor K; Raval, Keyur; JagadeeshBabu, P E

    2015-01-01

    Uricase (urate: oxygen oxidoreductase, EC 1.7.3.3), an enzyme belonging to the class of oxidoreductases, catalyzes the enzymatic oxidation of uric acid to allantoin and finds a wide variety of application as therapeutic and clinical reagent. In this study, uricase production ability of the bacterial strains isolated from deep litter poultry soil is investigated. The strain with maximum extracellular uricase production capability was identified as Xanthomonas fuscans subsp. aurantifolii based on 16S rRNA sequencing. Effect of various carbon and nitrogen sources on uricase productivity was investigated. The uricase production for this strain was optimized using statistically based experimental designs and resulted in uricase activity of 306 U/L, which is 2 times higher than initial uricase activity. Two-step purification, such as ammonium sulfate precipitation and aqueous two-phase system, was carried out and a twofold increase in yield and specific activity was observed.

  19. Regulation of the pigment optical density of an algal cell: filling the gap between photosynthetic productivity in the laboratory and in mass culture.

    PubMed

    Formighieri, Cinzia; Franck, Fabrice; Bassi, Roberto

    2012-11-30

    An increasing number of investors is looking at algae as a viable source of biofuels, beside cultivation for human/animal feeding or to extract high-value chemicals and pharmaceuticals. However, present biomass productivities are far below theoretical estimations implying that a large part of the available photosynthetically active radiation is not used in photosynthesis. Light utilisation inefficiency and rapid light attenuation within a mass culture due to high pigment optical density of wild type strains have been proposed as major limiting factors reducing solar-to-biomass conversion efficiency. Analysis of growth yields of mutants with reduced light-harvesting antennae and/or reduced overall pigment concentration per cell, generated by either mutagenesis or genetic engineering, could help understanding limiting factors for biomass accumulation in photobioreactor. Meanwhile, studies on photo-acclimation can provide additional information on the average status of algal cells in a photobioreactor to be used in modelling-based predictions. Identifying limiting factors in solar-to-biomass conversion efficiency is the first step for planning strategies of genetic improvement and domestication of algae to finally fill the gap between theoretical and industrial photosynthetic productivity. PMID:22426090

  20. Biodiesel production from lipids in wet microalgae with microwave irradiation and bio-crude production from algal residue through hydrothermal liquefaction.

    PubMed

    Cheng, Jun; Huang, Rui; Yu, Tao; Li, Tao; Zhou, Junhu; Cen, Kefa

    2014-01-01

    A cogeneration process of biodiesel and bio-crude was proposed to make full use of wet microalgae biomass. High-grade biodiesel was first produced from lipids in wet microalgae through extraction and transesterification with microwave irradiation. Then, low-grade bio-crude was produced from proteins and carbohydrates in the algal residue through hydrothermal liquefaction. The total yield (40.19%) and the total energy recovery (67.73%) of the cogenerated biodiesel and bio-crude were almost equal to those of the bio-oil obtained from raw microalgae through direct hydrothermal liquefaction. Upon microwave irradiation, proteins were partially hydrolyzed and the hydrolysates were apt for deaminization under the hydrothermal condition of the algal residue. Hence, the total remaining nitrogen (16.02%) in the cogenerated biodiesel and bio-crude was lower than that (27.06%) in the bio-oil. The cogeneration process prevented lipids and proteins from reacting to produce low-grade amides and other long-chain nitrogen compounds during the direct hydrothermal liquefaction of microalgae.

  1. Carbon conversion efficiency and population dynamics of a marine algae-bacteria consortium growing on simplified synthetic digestate: first step in a bioprocess coupling algal production and anaerobic digestion.

    PubMed

    Vasseur, Christophe; Bougaran, Gaël; Garnier, Matthieu; Hamelin, Jérôme; Leboulanger, Christophe; Le Chevanton, Myriam; Mostajir, Behzad; Sialve, Bruno; Steyer, Jean-Philippe; Fouilland, Eric

    2012-09-01

    Association of microalgae culture and anaerobic digestion seems a promising technology for sustainable algal biomass and biogas production. The use of digestates for sustaining the growth of microalgae reduces the costs and the environmental impacts associated with the substantial algal nutrient requirements. A natural marine algae-bacteria consortium was selected by growing on a medium containing macro nutrients (ammonia, phosphate and acetate) specific of a digestate, and was submitted to a factorial experimental design with different levels of temperature, light and pH. The microalgal consortium reached a maximum C conversion efficiency (i.e. ratio between carbon content produced and carbon supplied through light photosynthetic C conversion and acetate) of 3.6%. The presence of bacteria increased this maximum C conversion efficiency up to 6.3%. The associated bacterial community was considered beneficial to the total biomass production by recycling the carbon lost during photosynthesis and assimilating organic by-products from anaerobic digestion. PMID:22728186

  2. Extracellular Lipase and Protease Production from a Model Drinking Water Bacterial Community Is Functionally Robust to Absence of Individual Members.

    PubMed

    Willsey, Graham G; Wargo, Matthew J

    2015-01-01

    Bacteria secrete enzymes into the extracellular space to hydrolyze macromolecules into constituents that can be imported for microbial nutrition. In bacterial communities, these enzymes and their resultant products can be modeled as community property. Our goal was to investigate the impact of individual community member absence on the resulting community production of exoenzymes (extracellular enzymes) involved in lipid and protein hydrolysis. Our model community contained nine bacteria isolated from the potable water system of the International Space Station. Bacteria were grown in static conditions individually, all together, or in all combinations of eight species and exoproduct production was measured by colorimetric or fluorometric reagents to assess short chain and long chain lipases, choline-specific phospholipases C, and proteases. The exoenzyme production of each species grown alone varied widely, however, the enzyme activity levels of the mixed communities were functionally robust to absence of any single species, with the exception of phospholipase C production in one community. For phospholipase C, absence of Chryseobacterium gleum led to increased choline-specific phospholipase C production, correlated with increased growth of Burkholderia cepacia and Sphingomonas sanguinis. Because each individual species produced different enzyme activity levels in isolation, we calculated an expected activity value for each bacterial mixture using input levels or known final composition. This analysis suggested that robustness of each exoenzyme activity is not solely mediated by community composition, but possibly influenced by bacterial communication, which is known to regulate such pathways in many bacteria. We conclude that in this simplified model of a drinking water bacterial community, community structure imposes constraints on production and/or secretion of exoenzymes to generate a level appropriate to exploit a given nutrient environment.

  3. Extracellular Lipase and Protease Production from a Model Drinking Water Bacterial Community Is Functionally Robust to Absence of Individual Members.

    PubMed

    Willsey, Graham G; Wargo, Matthew J

    2015-01-01

    Bacteria secrete enzymes into the extracellular space to hydrolyze macromolecules into constituents that can be imported for microbial nutrition. In bacterial communities, these enzymes and their resultant products can be modeled as community property. Our goal was to investigate the impact of individual community member absence on the resulting community production of exoenzymes (extracellular enzymes) involved in lipid and protein hydrolysis. Our model community contained nine bacteria isolated from the potable water system of the International Space Station. Bacteria were grown in static conditions individually, all together, or in all combinations of eight species and exoproduct production was measured by colorimetric or fluorometric reagents to assess short chain and long chain lipases, choline-specific phospholipases C, and proteases. The exoenzyme production of each species grown alone varied widely, however, the enzyme activity levels of the mixed communities were functionally robust to absence of any single species, with the exception of phospholipase C production in one community. For phospholipase C, absence of Chryseobacterium gleum led to increased choline-specific phospholipase C production, correlated with increased growth of Burkholderia cepacia and Sphingomonas sanguinis. Because each individual species produced different enzyme activity levels in isolation, we calculated an expected activity value for each bacterial mixture using input levels or known final composition. This analysis suggested that robustness of each exoenzyme activity is not solely mediated by community composition, but possibly influenced by bacterial communication, which is known to regulate such pathways in many bacteria. We conclude that in this simplified model of a drinking water bacterial community, community structure imposes constraints on production and/or secretion of exoenzymes to generate a level appropriate to exploit a given nutrient environment. PMID:26599415

  4. Extracellular Lipase and Protease Production from a Model Drinking Water Bacterial Community Is Functionally Robust to Absence of Individual Members

    PubMed Central

    Willsey, Graham G.; Wargo, Matthew J.

    2015-01-01

    Bacteria secrete enzymes into the extracellular space to hydrolyze macromolecules into constituents that can be imported for microbial nutrition. In bacterial communities, these enzymes and their resultant products can be modeled as community property. Our goal was to investigate the impact of individual community member absence on the resulting community production of exoenzymes (extracellular enzymes) involved in lipid and protein hydrolysis. Our model community contained nine bacteria isolated from the potable water system of the International Space Station. Bacteria were grown in static conditions individually, all together, or in all combinations of eight species and exoproduct production was measured by colorimetric or fluorometric reagents to assess short chain and long chain lipases, choline-specific phospholipases C, and proteases. The exoenzyme production of each species grown alone varied widely, however, the enzyme activity levels of the mixed communities were functionally robust to absence of any single species, with the exception of phospholipase C production in one community. For phospholipase C, absence of Chryseobacterium gleum led to increased choline-specific phospholipase C production, correlated with increased growth of Burkholderia cepacia and Sphingomonas sanguinis. Because each individual species produced different enzyme activity levels in isolation, we calculated an expected activity value for each bacterial mixture using input levels or known final composition. This analysis suggested that robustness of each exoenzyme activity is not solely mediated by community composition, but possibly influenced by bacterial communication, which is known to regulate such pathways in many bacteria. We conclude that in this simplified model of a drinking water bacterial community, community structure imposes constraints on production and/or secretion of exoenzymes to generate a level appropriate to exploit a given nutrient environment. PMID:26599415

  5. Extracellular enzyme production and phylogenetic distribution of yeasts in wastewater treatment systems.

    PubMed

    Yang, Qingxiang; Zhang, Hao; Li, Xueling; Wang, Zhe; Xu, Ying; Ren, Siwei; Chen, Xuanyu; Xu, Yuanyuan; Hao, Hongxin; Wang, Hailei

    2013-02-01

    The abilities of yeasts to produce different extracellular enzymes and their distribution characteristics were studied in municipal, inosine fermentation, papermaking, antibiotic fermentation, and printing and dyeing wastewater treatment systems. The results indicated that of the 257 yeasts, 16, 14, 55, and 11 produced lipase, protease, manganese dependant peroxidase (MnP), and lignin peroxidase (LiP), respectively. They were distributed in 12 identified and four unidentified genera, in which Candida rugosa (AA-M17) and an unidentified Saccharomycetales (AA-Y5), Pseudozyma sp. (PH-M15), Candida sp. (MO-Y11), and Trichosporon montevideense (MO-M16) were shown to have the highest activity of lipase, protease, Mnp, and LiP, respectively. No yeast had amylase, cellulose, phytase, or laccase activity. Although only 60 isolates produced ligninolytic enzymes, 249 of the 257 yeasts could decolorize different dyes through the mechanism of biodegradation (222 isolates) or bio-sorption. The types of extracellular enzymes that the yeasts produced were significantly shaped by the types of wastewater treated. PMID:23261999

  6. Effects of Silver Sulphadiazine on Production of Extracellular Proteins by Strains of Staphylococcus Aureus Isolated from Burns Wound

    PubMed Central

    Javid Khojasteh, Vahideh; Alfakhri, Souad; Foster, Howard Anthony

    2016-01-01

    Previous studies had shown that sub-inhibitory concentrations of silver sulphadiazine (AgSD) stimulated the production of Toxic Shock Syndrome Toxin-1 in certain strains (responder strains) of Staphylococcus aureus and that protease production was also affected. No changes were detected in other strains (non-responders). Extracellular proteins from eleven responder and non-responder strains grown with and without AgSD were separated by SDS PAGE. There were three classes of response, responder strains that showed enhancement of synthesis of certain proteins, non-responder strains that showed no change and responder strains that showed a general decrease in exoprotein production in the early stages of growth. The results showed that the effects of AgSD were complex and that S. aureus strains were heterogenous with respect to their response to sub-inhibitory concentrations of AgSD. PMID:27642339

  7. Effects of Silver Sulphadiazine on Production of Extracellular Proteins by Strains of Staphylococcus Aureus Isolated from Burns Wound.

    PubMed

    Javid Khojasteh, Vahideh; Alfakhri, Souad; Foster, Howard Anthony

    2016-01-01

    Previous studies had shown that sub-inhibitory concentrations of silver sulphadiazine (AgSD) stimulated the production of Toxic Shock Syndrome Toxin-1 in certain strains (responder strains) of Staphylococcus aureus and that protease production was also affected. No changes were detected in other strains (non-responders). Extracellular proteins from eleven responder and non-responder strains grown with and without AgSD were separated by SDS PAGE. There were three classes of response, responder strains that showed enhancement of synthesis of certain proteins, non-responder strains that showed no change and responder strains that showed a general decrease in exoprotein production in the early stages of growth. The results showed that the effects of AgSD were complex and that S. aureus strains were heterogenous with respect to their response to sub-inhibitory concentrations of AgSD. PMID:27642339

  8. Leukotriene C4 production by murine mast cells: evidence of a role for extracellular leukotriene A4.

    PubMed

    Dahinden, C A; Clancy, R M; Gross, M; Chiller, J M; Hugli, T E

    1985-10-01

    The glutathione-containing leukotriene C4 (LTC4) is a major mediator of smooth muscle contraction and is released by mast cells when antigen interacts with cell-bound IgE. Antigen-stimulated mast cells undergo phospholipase activation. We report a pathway of LTC4 production by mast cells that does not require phospholipase activation but depends on the interaction of activated neutrophils with unstimulated mast cells, using as an intermediate extracellular leukotriene A4 (LTA4). The epoxide LTA4 is released by neutrophils and, together with leukotriene B4 and 5-hydroxyeicosatetraenoic acid, constitutes the major lipoxygenase metabolites found in supernatants of stimulated neutrophils. Five minutes after activation of neutrophils by calcium ionophore A23187 we measured 136 pmol of extracellular LTA4 per 10(7) neutrophils (range 40-300, n = 7) by trapping the epoxide with alcohols. Therefore, we conclude that LTA4 is not just an intracellular leukotriene precursor but is released as a lipoxygenase metabolite. LTA4 is known to be stabilized by albumin and is efficiently converted by mast cells into LTC4 even at low LTA4 concentrations. The LTA4 complexed to albumin is converted into LTC4 rapidly and completely within 10-15 min. More than 50% of the LTA4 presented to mast cells is metabolized to LTC4 at concentrations of LTA4 between 0.2 and 2 nmol of LTA4 per 10(7) mast cells. This observation establishes a potential physiologic role for extracellular LTA4. Therefore, interactions between various cell types that release or utilize LTA4 may provide an important metabolic pathway for the production of leukotrienes.

  9. Effect of algal recycling rate on the performance of Pediastrum boryanum dominated wastewater treatment high rate algal pond.

    PubMed

    Park, J B K; Craggs, R J

    2014-01-01

    Recycling a portion of gravity harvested algae promoted the dominance of a rapidly settling colonial alga, Pediastrum boryanum (P. boryanum) and improved both biomass productivity and settleability in High Rate Algal Pond (HRAP) treating domestic wastewater. The effect of algal recycling rate on HRAP performance was investigated using 12 replicate mesocosms (18 L) that were operated semi-continuously under ambient conditions. Three experiments were conducted during different seasons with each experiment lasting up to 36 days. Recycling 10%, 25%, and 50% of the 'mass' of daily algal production all increased total biomass concentration in the mesocosms. However, recycling >10% reduced the organic content (volatile suspended solids (VSS)) of the mesocosm biomass from 83% to 68% and did not further increase biomass productivity (based on VSS). This indicates that if a HRAP is operated with a low algal concentration and does not utilise all the available sunlight, algal recycling increases the algal concentration up to an optimum level, resulting in higher algal biomass productivity. Recycling 10% of the daily algal production not only increased biomass productivity by ∼40%, but increased biomass settleability by ∼25%, which was probably a consequence of the ∼30% increase in P. boryanum dominance in the mesocosms compared with controls without recycling.

  10. Extracellular acidification induces connective tissue growth factor production through proton-sensing receptor OGR1 in human airway smooth muscle cells

    SciTech Connect

    Matsuzaki, Shinichi; Ishizuka, Tamotsu; Yamada, Hidenori; Kamide, Yosuke; Hisada, Takeshi; Ichimonji, Isao; Aoki, Haruka; Yatomi, Masakiyo; Komachi, Mayumi; Tsurumaki, Hiroaki; Ono, Akihiro; Koga, Yasuhiko; Dobashi, Kunio; Mogi, Chihiro; Sato, Koichi; Tomura, Hideaki; Mori, Masatomo; Okajima, Fumikazu

    2011-10-07

    Highlights: {yields} The involvement of extracellular acidification in airway remodeling was investigated. {yields} Extracellular acidification alone induced CTGF production in human ASMCs. {yields} Extracellular acidification enhanced TGF-{beta}-induced CTGF production in human ASMCs. {yields} Proton-sensing receptor OGR1 was involved in acidic pH-stimulated CTGF production. {yields} OGR1 may play an important role in airway remodeling in asthma. -- Abstract: Asthma is characterized by airway inflammation, hyper-responsiveness and remodeling. Extracellular acidification is known to be associated with severe asthma; however, the role of extracellular acidification in airway remodeling remains elusive. In the present study, the effects of acidification on the expression of connective tissue growth factor (CTGF), a critical factor involved in the formation of extracellular matrix proteins and hence airway remodeling, were examined in human airway smooth muscle cells (ASMCs). Acidic pH alone induced a substantial production of CTGF, and enhanced transforming growth factor (TGF)-{beta}-induced CTGF mRNA and protein expression. The extracellular acidic pH-induced effects were inhibited by knockdown of a proton-sensing ovarian cancer G-protein-coupled receptor (OGR1) with its specific small interfering RNA and by addition of the G{sub q/11} protein-specific inhibitor, YM-254890, or the inositol-1,4,5-trisphosphate (IP{sub 3}) receptor antagonist, 2-APB. In conclusion, extracellular acidification induces CTGF production through the OGR1/G{sub q/11} protein and inositol-1,4,5-trisphosphate-induced Ca{sup 2+} mobilization in human ASMCs.

  11. Production of extracellular protease and glucose uptake in Bacillus clausii in steady-state and transient continuous cultures.

    PubMed

    Christiansen, Torben; Nielsen, Jens

    2002-08-28

    The production of the extracellular alkaline protease Savinase (EC 3.4.21.62) and glucose uptake in a non-sporulating strain of Bacillus clausii were investigated by analysing steady-state and transients during continuous cultivations. The specific production rate was found to have an optimum at a dilution rate between 0.14 and 0.17 h(-1), whereas the yield of Savinase on glucose was found to increase with decreasing specific growth rate. A linear relationship between the ribosomal RNA content and the specific production rate was found, indicating that the translational capacity may be limiting for product formation. The dynamics of the production of Savinase were studied during step changes in the dilution rate. During a step down in the dilution rate the specific production rate decreased immediately until it reached a new steady value. During a step-up an initial cease in the production rate was observed, but when glucose stopped to accumulate the production rate was regained. The glucose uptake was further investigated when chemostat cultures growing at different dilution rates were exposed to glucose pulses. The maximal glucose uptake capacity was found to be dependent on the initial specific growth rate. Furthermore, the adaptation to high glucose concentrations was faster at high dilution rates than at low dilution rates. PMID:12084482

  12. Withania somnifera attenuates acid production, acid tolerance and extra-cellular polysaccharide formation of Streptococcus mutans biofilms.

    PubMed

    Pandit, Santosh; Song, Kwang-Yeob; Jeon, Jae-Gyu

    2014-01-01

    Withania somnifera (Ashwagandha) is a plant of the Solanaceae family. It has been widely used as a remedy for a variety of ailments in India and Nepal. The plant has also been used as a controlling agent for dental diseases. The aim of the present study was to evaluate the activity of the methanol extract of W. somnifera against the physiological ability of cariogenic biofilms and to identify the components of the extract. To determine the activity of the extract, assays for sucrose-dependent bacterial adherence, glycolytic acid production, acid tolerance, and extracellular polysaccharide formation were performed using Streptococcus mutans biofilms. The viability change of S. mutans biofilms cells was also determined. A phytochemical analysis of the extract was performed using TLC and LC/MS/MS. The extract showed inhibitory effects on sucrose-dependent bacterial adherence (≥ 100 μg/ml), glycolytic acid production (≥ 300 μg/ml), acid tolerance (≥ 300 μg/ml), and extracellular polysaccharide formation (≥ 300 μg/ml) of S. mutans biofilms. However, the extract did not alter the viability of S. mutans biofilms cells in all concentrations tested. Based on the phytochemical analysis, the activity of the extract may be related to the presence of alkaloids, anthrones, coumarines, anthraquinones, terpenoids, flavonoids, and steroid lactones (withanolide A, withaferin A, withanolide B, withanoside IV, and 12-deoxy withastramonolide). These data indicate that W. somnifera may be a potential agent for restraining the physiological ability of cariogenic biofilms.

  13. Precursor-product relationship of intracellular and extracellular lipoteichoic acids of Streptococcus faecium.

    PubMed Central

    Kessler, R E; Shockman, G D

    1979-01-01

    Exponential biosynthesis and excretion of lipoteichoic acid (LTA) during the exponential phase of growth, and continued synthesis and excretion during valine starvation of Streptococcus faecium (S. faecalis ATCC 9790), were shown. During exponential growth, extracellular LTA (LTAx) accounted for approximately 13% of the total LTA in cultures, whereas during valine starvation, this percentage increased to approximately 60% within 4 h. LTAx was present in a low-molecular-weight, apparently deacylated form, whereas intracellular (LTAi) was present primarily in an apparently high-molecular-weight, acylated and micellar form. Experiments utilizing chases of either fully equilibrated or short pulses of [14C]- or [3H]glycerol were used to demonstrate that LTAx was derived directly from LTAi. PMID:106043

  14. Production, purification and characterization of a 50-kDa extracellular metalloprotease from Serratia marcescens.

    PubMed

    Salamone, P R; Wodzinski, R J

    1997-09-01

    The extracellular metalloprotease (SMP 6.1) produced by a soil isolate of Serratia marcescens NRRL B-23112 was purified and characterized. SMP 6.1 was purified from the culture supernatant by ammonium sulfate precipitation, acetone fractional precipitation, and preparative isoelectric focusing. SMP 6.1 has a molecular mass of approximately 50,900 Da by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE). The following substrates were hydrolyzed: casein, bovine serum albumin, and hide powder. SMP 6.1 has the characteristics of a metalloprotease, a pH optimum of 10.0, and a temperature optimum of 42 degrees C. The isoelectric point of the protease is 6.1. Restoration of proteolytic activity by in-gel renaturation after SDS-PAGE indicates a single polypeptide chain. SMP 6.1 is inhibited by EDTA (9 micrograms/ml) and not inhibited by antipain dihydrochloride (120 micrograms/ml), aprotinin (4 micrograms/ml), bestatin (80 micrograms/ml), chymostatin (50 micrograms/ml), E-64 (20 micrograms/ml), leupeptin (4 micrograms/ml), Pefabloc SC (2000 micrograms/ml), pepstatin (4 micrograms/ml), phosphoramidon (660 micrograms/ml), or phenylmethylsulfonyl fluoride (400 micrograms/ml). SMP 6.1 retains full activity in the presence of SDS (1% w/v), Tween-20 (1% w/v), Triton X-100 (1% w/v), ethanol (5% v/v), and 2-mercaptoethanol (0.5% v/v). The extracellular metalloprotease SMP 6.1 differs from the serratiopeptidase (Sigma) produced by S. marcescens ATCC 27117 in the following characteristics: isoelectric point, peptide mapping and nematolytic properties.

  15. Abiotic factors in colony formation: effects of nutrition and light on extracellular polysaccharide production and cell aggregates of Microcystis aeruginosa

    NASA Astrophysics Data System (ADS)

    Yang, Zhen; Kong, Fanxiang

    2013-07-01

    Colony morphology is important for Microcystis to sustain a competitive advantage in eutrophic lakes. The mechanism of colony formation in Microcystis is currently unclear. Extracellular polysaccharide (EPS) has been reported to play an important role in cell aggregate formation of some phytoplankton. Microcystis aeruginosa was cultivated under varied abiotic conditions, including different nutrient, light, and temperature conditions, to investigate their effects on EPS production and morphological change. The results show that nutrient concentration and light intensity have great effects on EPS productionin M. aeruginosa. There was a considerable increase in EPS production after M. aeruginosa was cultivated in adjusted culture conditions similar to those present in the field (28.9 mg C/L, 1.98 mg N/L, 0.65 mg P/L, light intensity: 100 μmol/(m2 · s)). These results indicate that abiotic factors might be one of the triggers for colony formation in Microcystis.

  16. Characterization of a novel RNA regulator of Erwinia carotovora ssp. carotovora that controls production of extracellular enzymes and secondary metabolites.

    PubMed

    Liu, Y; Cui, Y; Mukherjee, A; Chatterjee, A K

    1998-07-01

    The enterobacterium Erwinia carotovora ssp. carotovora strain 71 (hereafter Ecc71) produces extracellular enzymes such as pectate lyase isozymes (Pels), cellulase (Cel), polygalacturonase (Peh) and protease (Prt). These enzymes degrade plant cell wall components and are largely responsible for the elicitation of soft-rot diseases in plants and plant products. Ecc71 also produces HarpinEcc, the elicitor of hypersensitive reaction (HR) and the quorum-sensing signal, N-(3-oxohexanoyl)-L-homoserine lactone (OHL). OHL controls extracellular enzyme and HarpinEcc production. The levels of these enzymes, as well as the expression of hrpNEcc, the structural gene for HarpinEcc, and ohll, the gene specifying OHL synthesis, are negatively regulated by RsmaA. rsmB, formerly aepH, on the other hand, positively regulates extracellular enzyme production. 6His-RsmA recombinant protein purified from E. coli binds rsmB RNA as indicated by gel mobility shift assays. rsmB comprises 547 bp DNA, which is transcribed from a single start site immediately after a sigma70-like promoter. In Ecc71, two rsmB RNA species are detected: a full-length 479 base rsmB RNA and a 259 base rsmB' RNA. rsmB' DNA hybridizes with the 259 base and the 479 base transcripts. A 3' RNase protection assay revealed that the 259 base and the 479 base RNA species end at the same position immediately after the putative rho-independent terminator. The expression of rsmB-lacZ transcriptional fusions established that the rsmB' RNA is not produced because of the activation of an internal promoter. These data strongly suggest that the 259 base rsmB' RNA is derived by processing of the primary rsmB RNA. In Ecc71, rsmB' expression driven by the lac promoter causes overproduction of Pel, Peh, Cel and Prt, and accumulation of pel-1, peh-1, hrpNEcc and ohll transcripts. By contrast, a plasmid with the rsmB' DNA sequence deleted fails to cause overproduction of the extracellular enzymes in Ecc71. The rsmB' effect also occurs in

  17. Environmental feedbacks and engineered nanoparticles: mitigation of silver nanoparticle toxicity to Chlamydomonas reinhardtii by algal-produced organic compounds.

    PubMed

    Stevenson, Louise M; Dickson, Helen; Klanjscek, Tin; Keller, Arturo A; McCauley, Edward; Nisbet, Roger M

    2013-01-01

    The vast majority of nanotoxicity studies measures the effect of exposure to a toxicant on an organism and ignores the potentially important effects of the organism on the toxicant. We investigated the effect of citrate-coated silver nanoparticles (AgNPs) on populations of the freshwater alga Chlamydomonas reinhardtii at different phases of batch culture growth and show that the AgNPs are most toxic to cultures in the early phases of growth. We offer strong evidence that reduced toxicity occurs because extracellular dissolved organic carbon (DOC) compounds produced by the algal cells themselves mitigate the toxicity of AgNPs. We analyzed this feedback with a dynamic model incorporating algal growth, nanoparticle dissolution, bioaccumulation of silver, DOC production and DOC-mediated inactivation of nanoparticles and ionic silver. Our findings demonstrate how the feedback between aquatic organisms and their environment may impact the toxicity and ecological effects of engineered nanoparticles.

  18. Environmental Feedbacks and Engineered Nanoparticles: Mitigation of Silver Nanoparticle Toxicity to Chlamydomonas reinhardtii by Algal-Produced Organic Compounds

    PubMed Central

    Stevenson, Louise M.; Dickson, Helen; Klanjscek, Tin; Keller, Arturo A.; McCauley, Edward; Nisbet, Roger M.

    2013-01-01

    The vast majority of nanotoxicity studies measures the effect of exposure to a toxicant on an organism and ignores the potentially important effects of the organism on the toxicant. We investigated the effect of citrate-coated silver nanoparticles (AgNPs) on populations of the freshwater alga Chlamydomonas reinhardtii at different phases of batch culture growth and show that the AgNPs are most toxic to cultures in the early phases of growth. We offer strong evidence that reduced toxicity occurs because extracellular dissolved organic carbon (DOC) compounds produced by the algal cells themselves mitigate the toxicity of AgNPs. We analyzed this feedback with a dynamic model incorporating algal growth, nanoparticle dissolution, bioaccumulation of silver, DOC production and DOC-mediated inactivation of nanoparticles and ionic silver. Our findings demonstrate how the feedback between aquatic organisms and their environment may impact the toxicity and ecological effects of engineered nanoparticles. PMID:24086348

  19. Annual production of five species of Chironomidae (Diptera) in Houhu Lake, a typical algal lake (Wuhan, China)

    NASA Astrophysics Data System (ADS)

    Yun-Jun, Yan; Yan-Ling, Liang; Hong-Zhu, Wang

    1999-06-01

    Annual production and life cycle of five dominant species of Chironomidae ( Chironomus plumosus, Cryptochironomus sp., Tokunagayusurika akamusi, Procladius sp., Clinotanypus sp.) were studied with samples collected monthly from April, 1996 to March, 1997 in Houhu Lake at four stations. Based on instar-frequency data, C. plumosus was univoltine, while the other four were bivoltine. Production rates in grams wet weight m-2a-1 calculated by the size-frequency method were C. plumosus, 2.170; Cryptochironomus sp., 0.602; T. akamusi, 3.160; Procladius sp., 0.964; Clinotanypus sp., 0.390. Their P/B ratios were 3.9, 4.9, 4.4, 5.3 and 6.6, respectively.

  20. Regional Algal Biofuel Production Potential in the Coterminous United States as Affected by Resource Availability Trade-offs

    SciTech Connect

    Venteris, Erik R.; Skaggs, Richard; Wigmosta, Mark S.; Coleman, Andre M.

    2014-03-15

    The warm sunny climate and unoccupied arid lands in the American southwest are favorable factors for algae cultivation. However, additional resources affect the overall viability of specific sites and regions. We investigated the tradeoffs between growth rate, water, and CO2 availability and costs for two strains: N. salina and Chlorella sp. We conducted site selection exercises (~88,000 US sites) to produce 21 billion gallons yr-1 (BGY) of renewable diesel (RD). Experimental trials from the National Alliance for Advanced Biofuels and Bio-Products (NAABB) team informed the growth model of our Biomass Assessment Tool (BAT). We simulated RD production by both lipid extraction and hydrothermal liquefaction. Sites were prioritized by the net value of biofuel minus water and flue gas costs. Water cost models for N. salina were based on seawater and high salinity groundwater and for Chlorella, fresh and brackish groundwater. CO2 costs were based on a flue gas delivery model. Selections constrained by production and water were concentrated along the Gulf of Mexico and southeast Atlantic coasts due to high growth rates and low water costs. Adding flue gas constraints increased the spatial distribution, but the majority of sites remained in the southeast. The 21 BGY target required ~3.8 million hectares of mainly forest (41.3%) and pasture (35.7%). Exclusion in favor of barren and scrub lands forced most production to the southwestern US, but with increased water consumption (5.7 times) and decreased economic efficiency (-38%).

  1. Accelerating Commercialization of Algal Biofuels Through Partnerships (Brochure)

    SciTech Connect

    Not Available

    2011-10-01

    This brochure describes National Renewable Energy Laboratory's (NREL's) algal biofuels research capabilities and partnership opportunities. NREL is accelerating algal biofuels commercialization through: (1) Advances in applied biology; (2) Algal strain development; (3) Development of fuel conversion pathways; (4) Techno-economic analysis; and (5) Development of high-throughput lipid analysis methodologies. NREL scientists and engineers are addressing challenges across the algal biofuels value chain, including algal biology, cultivation, harvesting and extraction, and fuel conversion. Through partnerships, NREL can share knowledge and capabilities in the following areas: (1) Algal Biology - A fundamental understanding of algal biology is key to developing cost-effective algal biofuels processes. NREL scientists are experts in the isolation and characterization of microalgal species. They are identifying genes and pathways involved in biofuel production. In addition, they have developed a high-throughput, non-destructive technique for assessing lipid production in microalgae. (2) Cultivation - NREL researchers study algal growth capabilities and perform compositional analysis of algal biomass. Laboratory-scale photobioreactors and 1-m2 open raceway ponds in an on-site greenhouse allow for year-round cultivation of algae under a variety of conditions. A bioenergy-focused algal strain collection is being established at NREL, and our laboratory houses a cryopreservation system for long-term maintenance of algal cultures and preservation of intellectual property. (3) Harvesting and Extraction - NREL is investigating cost-effective harvesting and extraction methods suitable for a variety of species and conditions. Areas of expertise include cell wall analysis and deconstruction and identification and utilization of co-products. (4) Fuel Conversion - NREL's excellent capabilities and facilities for biochemical and thermochemical conversion of biomass to biofuels are being

  2. Production of Secretory and Extracellular N-Linked Glycoproteins in Escherichia coli▿ †

    PubMed Central

    Fisher, Adam C.; Haitjema, Charles H.; Guarino, Cassandra; Çelik, Eda; Endicott, Christine E.; Reading, Craig A.; Merritt, Judith H.; Ptak, A. Celeste; Zhang, Sheng; DeLisa, Matthew P.

    2011-01-01

    The Campylobacter jejuni pgl gene cluster encodes a complete N-linked protein glycosylation pathway that can be functionally transferred into Escherichia coli. In this system, we analyzed the interplay between N-linked glycosylation, membrane translocation and folding of acceptor proteins in bacteria. We developed a recombinant N-glycan acceptor peptide tag that permits N-linked glycosylation of diverse recombinant proteins expressed in the periplasm of glycosylation-competent E. coli cells. With this “glycosylation tag,” a clear difference was observed in the glycosylation patterns found on periplasmic proteins depending on their mode of inner membrane translocation (i.e., Sec, signal recognition particle [SRP], or twin-arginine translocation [Tat] export), indicating that the mode of protein export can influence N-glycosylation efficiency. We also established that engineered substrate proteins targeted to environments beyond the periplasm, such as the outer membrane, the membrane vesicles, and the extracellular medium, could serve as substrates for N-linked glycosylation. Taken together, our results demonstrate that the C. jejuni N-glycosylation machinery is compatible with distinct secretory mechanisms in E. coli, effectively expanding the N-linked glycome of recombinant E. coli. Moreover, this simple glycosylation tag strategy expands the glycoengineering toolbox and opens the door to bacterial synthesis of a wide array of recombinant glycoprotein conjugates. PMID:21131519

  3. Production, Purification, and Properties of Extracellular Carboxyl Esterases from Bacillus subtilis NRRL 365

    PubMed Central

    Meghji, K.; Ward, O. P.; Araujo, A.

    1990-01-01

    Bacillus subtilis NRRL 365 produced high extracellular carboxyl esterase activity in submerged culture media containing wheat bran, corn steep liquor, and salts. Supplementation of this medium with glucose reduced esterase activity to 37% of that in the unsupplemented control. Esterase activity was purified by ammonium sulfate fractionation, DEAE-Sephadex A-50 ion-exchange chromatography with sodium chloride gradient elution, and preparative polyacrylamide gel electrophoresis. The resultant purified components, esterases I and II, manifested single bands following silver staining of polyacrylamide gel electrophoresis gels and had final specific activities of 80 and 520 U/mg, respectively. Molecular weights for components I and II were 36,000 and 105,000 to 110,000, respectively. Esterases I and II both had a pH optimum of 8.0, with relative activities of 10 and 85%, respectively, at pH 9.0. Kms with p-nitrophenylacetate were 0.91 mM for esterase I and 0.67 mM for esterase II. In general, patterns of enzyme inhibition were similar for both components. Differences were observed in the relative activities of esterases I and II towards p-nitrophenyl esters of acetate, propionate, and butyrate; Activity ratios for components I and II were 100:94:48 and 100:36:23, respectively. The purified components did not hydrolyze long-chain triglycerides and did not manifest proteolytic activity. Images PMID:16348375

  4. Buckling Reduces eNOS Production and Stimulates Extracellular Matrix Remodeling in Arteries in Organ Culture.

    PubMed

    Xiao, Yangming; Liu, Qin; Han, Hai-Chao

    2016-09-01

    Artery buckling alters the fluid shear stress and wall stress in the artery but its temporal effect on vascular wall remodeling is poorly understood. The purpose of this study was to investigate the early effect of artery buckling on endothelial nitric oxide synthase (eNOS) expression and extracellular matrix remodeling. Bilateral porcine carotid arteries were maintained in an ex vivo organ culture system with and without buckling while under the same physiological pressure and flow rate for 3-7 days. Matrix metalloproteinase-2 (MMP-2), MMP-9, fibronectin, elastin, collagen I, III and IV, tissue inhibitor of metalloproteinase-2 (TIMP-2), and eNOS were determined using Western blotting and immunohistochemistry. Our results showed that MMP-2 expression level was significantly higher in buckled arteries than in the controls and higher at the inner curve than at the outer curve of buckled arteries, while collagen IV content showed an opposite trend, suggesting that artery buckling increased MMP-2 expression and collagen IV degradation in a site-specific fashion. However, no differences for MMP-9, fibronectin, elastin, collagen I, III, and TIMP-2 were observed among the outer and inner curve sides of buckled arteries and straight controls. Additionally, eNOS expression was significantly decreased in buckled arteries. These results suggest that artery buckling triggers uneven wall remodeling that could lead to development of tortuous arteries. PMID:26913855

  5. Extracellular haem peroxidases mediate Mn(II) oxidation in a marine Roseobacter bacterium via superoxide production.

    PubMed

    Andeer, Peter F; Learman, Deric R; McIlvin, Matt; Dunn, James A; Hansel, Colleen M

    2015-10-01

    Manganese (Mn) oxides are among the strongest sorbents and oxidants in environmental systems. A number of biotic and abiotic pathways induce the oxidation of Mn(II) to Mn oxides. Here, we use a combination of proteomic analyses and activity assays, to identify the enzyme(s) responsible for extracellular superoxide-mediated Mn oxide formation by a bacterium within the ubiquitous Roseobacter clade. We show that animal haem peroxidases (AHPs) located on the outer membrane and within the secretome are responsible for Mn(II) oxidation. These novel peroxidases have previously been implicated in direct Mn(II) oxidation by phylogenetically diverse bacteria. Yet, we show that in this Roseobacter species, AHPs mediate Mn(II) oxidation not through a direct reaction but by producing superoxide and likely also by degrading hydrogen peroxide. These findings point to a eukaryotic-like oscillatory oxidative-peroxidative enzymatic cycle by these AHPs that leads to Mn oxide formation by this organism. AHP expression appears unaffected by Mn(II), yet the large energetic investment required to produce and secrete these enzymes points to an as yet unknown physiological function. These findings are further evidence that bacterial peroxidases and secreted enzymes, in general, are unappreciated controls on the cycling of metals and reactive oxygen species (ROS), and by extension carbon, in natural systems.

  6. Evaluation of anticoagulant activity of two algal polysaccharides.

    PubMed

    Faggio, C; Pagano, M; Dottore, A; Genovese, G; Morabito, M

    2016-09-01

    Marine algae are important sources of phycocolloids like agar, carrageenans and alginates used in industrial applications. Algal polysaccharides have emerged as an important class of bioactive products showing interesting properties. The aim of our study was to evaluate the potential uses as anticoagulant drugs of algal sulphate polysaccharides extracted from Ulva fasciata (Chlorophyta) and Agardhiella subulata (Rhodophyta) collected in Ganzirri Lake (Cape Peloro Lagoon, north-eastern Sicily, Italy). Toxicity of algal extracts through trypan blue test and anticoagulant action measured by activated partial thromboplastin time (APTT), prothrombin time (PT) test has been evaluated. Algal extracts showed to prolong the PT and APTT during the coagulation cascade and to avoid the blood coagulation of samples. Furthermore, the algal extracts lack toxic effects towards cellular metabolism and their productions are relatively at low cost. This permits to consider the algae as the biological source of the future.

  7. Algal biocathode for in situ terminal electron acceptor (TEA) production: synergetic association of bacteria-microalgae metabolism for the functioning of biofuel cell.

    PubMed

    Venkata Mohan, S; Srikanth, S; Chiranjeevi, P; Arora, Somya; Chandra, Rashmi

    2014-08-01

    Replacement of energy intensive mechanical aeration with sustainable oxygenic photosynthesis by microalgae at cathode was studied in dual-chambered microbial fuel cell (MFC). The synergistic association between bacterial fermentation at anode and the oxygenic photosynthesis of microalgae at cathode facilitated good power output as well as treatment efficiency. However, MFC operation during spring showed higher bioelectrogenic activity (57.0 mW/m(2)) over summer (1.1 mW/m(2)) due to the higher oxygenic photosynthetic activity of microalgae and respective dissolved oxygen (DO) levels. This can be attributed to RuBisCO inactivation under high temperatures and light intensity of summer, which prevented rich algal biomass growth as well as their photosynthetic activity. Unlike abiotic cathode, the algal cathode potential increased with operation time due to the algal biomass growth during spring but was negligible during summer. The catalytic currents on voltammetric signatures and the bioprocess parameters also corroborated well with the observed power output.

  8. Algal pigment distribution and primary production in the eastern Mediterranean as derived from coastal zone color scanner observations

    NASA Astrophysics Data System (ADS)

    Antoine, David; Morel, André; André, Jean-Michel

    1995-08-01

    About 300 coastal zone color scanner (CZCS) scenes, gathered over the eastern Mediterranean basin mostly during the years 1979-1981, have been processed from level 1 by using improved pixel-by-pixel procedures for the atmospheric correction and pigment retrieval. The seasonal evolution of the upper ocean pigment concentration is described and analyzed within the whole basin and its subbasins. From the chlorophyll concentration in the top layer, and by using statistical relationships, the depth-integrated pigment content is estimated and used in conjunction with a light-photosynthesis model to estimate the carbon fixation. The model relies on a set of physiological parameters, selected after the validation of the light-photosynthesis model and not on locally measured parameters. Additional information needed in the modeling are the photosynthetically available radiation (computed from astronomic and atmospheric parameters, combined with a cloud climatology), sea temperature and mixed-layer depth (taken from Levitus (1982)). Actually, the model is used to generate look-up tables in such a way that all possible situations (concerning available radiation, chlorophyll concentration, and temperature) are covered. The appropriate situation associated with any pixel is selected from these tables to generate primary production maps. Despite a relatively good spatial coverage, studying the interannual variability of the pigment distribution and primary production appeared to be impossible. Therefore 12 "climatological" monthly chlorophyll maps have been produced by merging the data corresponding to several years. The carbon fixation rates in each of the subbasins have been computed on a monthly basis, and annual mean values derived thereafter. The primary production values are compared with sparse field determinations. They are also compared with those previously derived for the Western basin, also by using CZCS data (Morel and André, 1991). When put together, these

  9. Catalytic effect of ultrananocrystalline Fe3O4 on algal bio-crude production via HTL process

    NASA Astrophysics Data System (ADS)

    Rojas-Pérez, Arnulfo; Diaz-Diestra, Daysi; Frias-Flores, Cecilia B.; Beltran-Huarac, Juan; Das, K. C.; Weiner, Brad R.; Morell, Gerardo; Díaz-Vázquez, Liz M.

    2015-10-01

    We report a comprehensive quantitative study of the production of refined bio-crudes via a controlled hydrothermal liquefaction (HTL) process using Ulva fasciata macroalgae (UFMA) as biomass and ultrananocrystalline Fe3O4 (UNCFO) as catalyst. X-ray diffraction and electron microscopy were applied to elucidate the formation of the high-quality nanocatalysts. Gas chromatography-mass spectroscopy (GC-MS) and CHNS analyses showed that the bio-crude yield and carbon/oxygen ratios increase as the amount of UNCFO increases, reaching a peak value of 32% at 1.25 wt% (a 9% increase when compared to the catalyst-free yield). The bio-crude is mainly composed of fatty acids, alcohols, ketones, phenol and benzene derivatives, and hydrocarbons. Their relative abundance changes as a function of catalyst concentration. FTIR spectroscopy and vibrating sample magnetometry revealed that the as-produced bio-crudes are free of iron species, which accumulate in the generated bio-chars. Our findings also indicate that the energy recovery values via the HTL process are sensitive to the catalyst loading, with a threshold loading of 1.25 wt%. GC-MS studies show that the UNCFO not only influences the chemical nature of the resulting bio-crudes and bio-chars, but also the amount of fixed carbons in the solid residues. The detailed molecular characterization of the bio-crudes and bio-chars catalyzed by UNCFO represents the first systematic study reported using UFMA. This study brings forth new avenues to advance the highly-pure bio-crude production employing active, heterogeneous catalyst materials that are recoverable and recyclable for continuous thermochemical reactions.We report a comprehensive quantitative study of the production of refined bio-crudes via a controlled hydrothermal liquefaction (HTL) process using Ulva fasciata macroalgae (UFMA) as biomass and ultrananocrystalline Fe3O4 (UNCFO) as catalyst. X-ray diffraction and electron microscopy were applied to elucidate the formation of

  10. Algal Bloom Detection from HICO

    NASA Astrophysics Data System (ADS)

    Amin, Ruhul; Gould, Richard

    2014-05-01

    Ocean color satellites provide daily, global views of marine bio-optical properties in the upper ocean at various spatial scales. The most productive area of the global ocean is the coastal zone which is heavily impacted by urban and agricultural runoff, transportation, recreation, and oil and gas production. In recent years, harmful algal blooms (HABs) have become one of the serious environmental problems in the coastal areas on a global scale. The global nature of the problem has expanded in its frequency, severity, and extent over the last several decades. Human activities and population increases have contributed to an increase in various toxic and noxious algal species in the coastal regions worldwide. Eutrophication in estuaries and coastal waters is believed to be the major factor causing HABs. In this study, we assess the applicability of the Red Band Difference (RBD) HAB detection algorithm on data from the Hyperspectral Imager for the Coastal Ocean (HICO). Our preliminary results show that due to various uncertainties such as atmospheric correction, calibration and possibly also the relatively low signal-to-noise ratio of HICO for fluorescence detection, it is difficult to extract the fluorescence portion of the reflectance spectrum that RBD uses for bloom detection. We propose an improved bloom detection technique for HICO using red and NIR bands. Our results are validated using other space-borne and ground based measurements.

  11. Influence of protoplast fusion between two Trichoderma spp. on extracellular enzymes production and antagonistic activity

    PubMed Central

    Hassan, Mohamed M.

    2014-01-01

    mycoparasitism effect of the extracellular enzymes. PMID:26019588

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

    PubMed

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

    2011-06-01

    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

  13. Biocatalytic production of enantiopure cyclohexane-trans-1,2-diol using extracellular lipases from Bacillus subtilis.

    PubMed

    Detry, Jean; Rosenbaum, Thorsten; Lütz, Stephan; Hahn, Doris; Jaeger, Karl-Erich; Müller, Michael; Eggert, Thorsten

    2006-10-01

    Two extracellular lipases from Bacillus subtilis, B. subtilis lipase A and lipase B, have been expressed in the heterologous host Escherichia coli, biochemically characterized and used for the kinetic resolution of (rac)-trans-1,2-diacetoxycyclohexane. Both enzymes were selectively acting on the (R,R)-enantiomer of the racemic substrate, highly specifically hydrolyzing only one of the two ester groups present, thus allowing the preparation of enantiopure (R,R)- and (S,S)-cyclohexane-trans-1,2-diol. The reaction conditions for the use of purified enzyme and crude cell lyophilizate were optimized and reactions in batch and repetitive batch modes were carried out on a preparative scale to yield enantiopure product (>99% enantiomeric excess). PMID:16586103

  14. Assessment of a Novel Algal Strain Chlamydomonas debaryana NIREMACC03 for Mass Cultivation, Biofuels Production and Kinetic Studies.

    PubMed

    Mishra, Sanjeev; Singh, Neetu; Sarma, Anil Kumar

    2015-08-01

    A novel microalgae strain Chlamydomonas debaryana (KJ210856) was isolated from a freshwater lake of Punjab, India, and cultivated considering climatic sustainability and inherent adaptability concern. C. debaryana was grown in a 30-L indoor photobioreactor to study the mass cultivation prospect and biofuel potential. Physicochemical characterization of biomass and the lipid was performed with effect to nitrogen stress. It showed a higher biomass yield (1.58 ± 0.02 g L(-1), dry weight) and twofold increase in lipid yield (552.78 ± 9 mg L(-1)) with 34.2 ± 0.19 % lipid content under nitrogen deficient condition. Strikingly, increase in triglycerides achieved with nitrogen depletion containing over 96 % of total fatty acids (C 14, C 16, and C 18). Proximate and ultimate analysis suggested the presence of relatively higher volatile matter and carbon-hydrogen ratio. Furthermore, lower moisture and ash content signified C. debaryana biomass has promising features towards biofuel applications. The pyrolytic behavior of the whole biomass was also studied using thermogravimetric analyzer (TGA) and kinetic parameters were estimated using different methods. Promising growth rate and lipid yield leading to feasible biofuel feed stock production in indoor photobioreactor along with autosediment potential of cells validates C. debaryana NIREMACC03, a potential strain for mass cultivation.

  15. Assessment of a Novel Algal Strain Chlamydomonas debaryana NIREMACC03 for Mass Cultivation, Biofuels Production and Kinetic Studies.

    PubMed

    Mishra, Sanjeev; Singh, Neetu; Sarma, Anil Kumar

    2015-08-01

    A novel microalgae strain Chlamydomonas debaryana (KJ210856) was isolated from a freshwater lake of Punjab, India, and cultivated considering climatic sustainability and inherent adaptability concern. C. debaryana was grown in a 30-L indoor photobioreactor to study the mass cultivation prospect and biofuel potential. Physicochemical characterization of biomass and the lipid was performed with effect to nitrogen stress. It showed a higher biomass yield (1.58 ± 0.02 g L(-1), dry weight) and twofold increase in lipid yield (552.78 ± 9 mg L(-1)) with 34.2 ± 0.19 % lipid content under nitrogen deficient condition. Strikingly, increase in triglycerides achieved with nitrogen depletion containing over 96 % of total fatty acids (C 14, C 16, and C 18). Proximate and ultimate analysis suggested the presence of relatively higher volatile matter and carbon-hydrogen ratio. Furthermore, lower moisture and ash content signified C. debaryana biomass has promising features towards biofuel applications. The pyrolytic behavior of the whole biomass was also studied using thermogravimetric analyzer (TGA) and kinetic parameters were estimated using different methods. Promising growth rate and lipid yield leading to feasible biofuel feed stock production in indoor photobioreactor along with autosediment potential of cells validates C. debaryana NIREMACC03, a potential strain for mass cultivation. PMID:26093613

  16. Regulation of Extracellular Protease Production in Bacillus cereus T: Characterization of Mutants Producing Altered Amounts of Protease

    PubMed Central

    Aronson, A. I.; Angelo, N.; Holt, S. C.

    1971-01-01

    Twenty-nine mutants of Bacillus cereus T were selected on casein agar for their inability to produce large amounts of extracellular protease. They all formed spores, and 27 were also auxotrophs for purines or pyrimidines. Upon reversion to prototrophy, a large fraction regained the capacity to produce protease. Conversely, reversion to normal protease production resulted in loss of the purine or pyrimidine requirement in a large fraction of the revertants. One spontaneous low-protease-producing pyrimidine auxotroph studied in detail grew as well as the wild type and produced spores which were identical to those produced by the wild type on the basis of heat resistance, dipicolinic acid content, density, and appearance in the electron microscope. The rate of protein turnover in the mutant was the same as the wild type. The mutant did grow poorly, however, when casein was the principal carbon source. A mutant excreting 5 to 10 times as much protease as the wild type was isolated as a secondary mutation from the hypoproducer discussed above. Loss of the pyrimidine requirement in this case did not alter the regulation of protease production. Although the secondary mutant grew somewhat faster in most media than the wild type, the final cell yield was lower. The spores of this mutant appeared to have excess coat on the basis of both electron microscopic and chemical studies. There appear to be closely related but distinct catabolic controls for both extracellular protease and spore formation. These controls can be dissociated as for the hypoproducers but can also appear integrated as for the hyperprotease producer. Images PMID:4104235

  17. Algal functional annotation tool

    SciTech Connect

    2012-07-12

    Abstract BACKGROUND: Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations to interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. DESCRIPTION: The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG

  18. Algal functional annotation tool

    2012-07-12

    Abstract BACKGROUND: Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations tomore » interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. DESCRIPTION: The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on

  19. Optimization of pretreatment and fermentation conditions for production of extracellular cellulase complex using sugarcane bagasse

    PubMed Central

    Ashfaque, Mohammad; Solomon, Sushil; Pathak, Neelam

    2014-01-01

    Sugarcane bagasse (SCB), a lignocellulosic byproduct of juice extraction from sugarcane, is rich in cellulose (40-42%). This could be used as a substrate for the production of cellulase complex. Fermentation conditions were optimized for production of cellulase complex (CMCase, Cellulobiase and FPase) by wild type Trichoderma sp. using sugarcane bagasse as sole carbon source. Alkaline treatment (2% NaOH) of bagasse (AlSCB) was found suitable for the production of reducing sugar over the acidic pretreatment method. After 5 days of incubation period, 5% substrate concentration at pH 5.0 and 400C resulted in maximum production of CMCase (0.622 U), while maximum (3.388 U) production of cellulobiase was obtained at 300C. The CMCase was precipitated and purified to the extent of 59.06 fold by affinity chromatography with 49.09% recovery. On 12% SDS-PAGE, a single band corresponding to 33 kDa was observed. The Km and Vmax for CMCase from Trichoderma was found 507.04 mg/ml and 65.32 mM/min, respectively. The enzyme exhibited maximum activity at 300C at pH-5.0 (0.363 U) and was stable over range of 20-60°C and pH 5.0-7.5. PMID:25489168

  20. High-level extracellular production of alkaline polygalacturonate lyase in Bacillus subtilis with optimized regulatory elements.

    PubMed

    Zhang, Junjiao; Kang, Zhen; Ling, Zhenmin; Cao, Wenlong; Liu, Long; Wang, Miao; Du, Guocheng; Chen, Jian

    2013-10-01

    The present work aims to construct a robust recombinant Bacillus subtilis to achieve secretory production of alkaline polygalacturonate lyase (PGL). First, 6 signal peptides (amyX, bpr, vpr, yvgO, wapA and nprE) were screened with a semi-rational approach and comparatively investigated their effects on the production of PGL. The signal peptide bpr directed efficient PGL secretory expression and increased PGL titer to 313.7 U mL(-1). By optimizing and applying strong promoter P43 and Shine-Dalgarno sequence, higher titer of 446.3 U mL(-1) PGL was achieved. Finally, the capacity of the recombinant B. subtilis WB43CB was evaluated with a fed-batch strategy in 3 L fermentor. The PGL titer reached 632.6 U mL(-1) with a productivity of 17.6 U mL(-1) h(-1), which was the highest secretory production of PGL by the B. subtilis system. The recombinant B. subtilis strain WB43CB constructed in the present work has great potential in production of alkaline PGL.

  1. Production of extracellular exoinulinase from Kluyveromyces marxianus YS-1 using root tubers of Asparagus officinalis.

    PubMed

    Singh, R S; Bhermi, H K

    2008-10-01

    Root tubers of Asparagus officinalis were used as a source of raw inulin for the production of exoinulinase (EC 3.2.1.7) from Kluyveromyces marxianus YS-1. Root extract prepared at 10kg/cm2 pressure for 10min showed maximum inulinase production. Medium components and process parameters were standardized to improve the enzyme production. Inulinase yield of 40.2IU/mL in a medium containing raw inulin (3.5%), beef extract (2%), SDS (0.001%), Mn2+ (2.0mM), Mg2+ (1.5mM), Co2+ (2mM) and pH 6.5 has been obtained under agitation (150rpm) after 60h of incubation at 30 degrees C at shake flask level. After optimization, the enzyme production was 4.8 times more than the basal medium. To test the feasibility of raw inulin from A. officinalis for the production of inulinase, trials were also made in a bioreactor (1.5L). Inulinase activity of 50.2IU/mL was obtained from raw inulin (4.0%) under agitation (200rpm) and aeration (0.75vvm) at 30 degrees C after 60h of fermentation. Inulinase yield in bioreactor was almost six times higher than the basal medium used initially in shake flask.

  2. Production of extracellular exoinulinase from Kluyveromyces marxianus YS-1 using root tubers of Asparagus officinalis.

    PubMed

    Singh, R S; Bhermi, H K

    2008-10-01

    Root tubers of Asparagus officinalis were used as a source of raw inulin for the production of exoinulinase (EC 3.2.1.7) from Kluyveromyces marxianus YS-1. Root extract prepared at 10kg/cm2 pressure for 10min showed maximum inulinase production. Medium components and process parameters were standardized to improve the enzyme production. Inulinase yield of 40.2IU/mL in a medium containing raw inulin (3.5%), beef extract (2%), SDS (0.001%), Mn2+ (2.0mM), Mg2+ (1.5mM), Co2+ (2mM) and pH 6.5 has been obtained under agitation (150rpm) after 60h of incubation at 30 degrees C at shake flask level. After optimization, the enzyme production was 4.8 times more than the basal medium. To test the feasibility of raw inulin from A. officinalis for the production of inulinase, trials were also made in a bioreactor (1.5L). Inulinase activity of 50.2IU/mL was obtained from raw inulin (4.0%) under agitation (200rpm) and aeration (0.75vvm) at 30 degrees C after 60h of fermentation. Inulinase yield in bioreactor was almost six times higher than the basal medium used initially in shake flask. PMID:18280145

  3. Distribution, behavior, and condition of herbivorous fishes on coral reefs track algal resources.

    PubMed

    Tootell, Jesse S; Steele, Mark A

    2016-05-01

    Herbivore distribution can impact community structure and ecosystem function. On coral reefs, herbivores are thought to play an important role in promoting coral dominance, but how they are distributed relative to algae is not well known. Here, we evaluated whether the distribution, behavior, and condition of herbivorous fishes correlated with algal resource availability at six sites in the back reef environment of Moorea, French Polynesia. Specifically, we tested the hypotheses that increased algal turf availability would coincide with (1) increased biomass, (2) altered foraging behavior, and (3) increased energy reserves of herbivorous fishes. Fish biomass and algal cover were visually estimated along underwater transects; behavior of herbivorous fishes was quantified by observations of focal individuals; fish were collected to assess their condition; and algal turf production rates were measured on standardized tiles. The best predictor of herbivorous fish biomass was algal turf production, with fish biomass increasing with algal production. Biomass of herbivorous fishes was also negatively related to sea urchin density, suggesting competition for limited resources. Regression models including both algal turf production and urchin density explained 94 % of the variation in herbivorous fish biomass among sites spread over ~20 km. Behavioral observations of the parrotfish Chlorurus sordidus revealed that foraging area increased as algal turf cover decreased. Additionally, energy reserves increased with algal turf production, but declined with herbivorous fish density, implying that algal turf is a limited resource for this species. Our findings support the hypothesis that herbivorous fishes can spatially track algal resources on coral reefs.

  4. High-level extracellular production of glucose oxidase by recombinant Pichia pastoris using a combined strategy.

    PubMed

    Gu, Lei; Zhang, Juan; Liu, Baihong; Du, Guocheng; Chen, Jian

    2015-02-01

    In this work, a combined strategy was developed to improve the production of glucose oxidase (GOD) (EC 1.1.3.4) in Pichia pastoris. One of the main challenges facing protein production by the high-density fermentation of P. pastoris is the high demand for oxygen. Another challenge is how to balance a reduction in oxygen consumption and its effects on protein production. Herein, a combined strategy involving mannitol co-feeding, two-stage methanol induction, and the co-expression of the transcriptional activator general control non-derepressible 4 (GCN4) from P. pastoris was used. A two-stage, co-feeding strategy, based on a mannitol/methanol mixture in a 3-L fermentor was used to enhance cell viability and protein production. This resulted in an increased GOD yield of 1208.2 U/mL compared with a control strain (427.6 U/mL). An increase in the copy number of the GCN4 gene enhanced the GOD yield (1634.7 U/mL) by 2.8-fold and the protein concentration (19.55 g/L) by 1.58-fold compared with the control (7.59 g/L). This strategy illustrates a way to overcome the high oxygen requirement during high-density fermentation of P. pastoris and balances the reduction of oxygen consumption and protein production. Moreover, the series of strategies presented in this work provide valuable and novel information for the industrial production of GOD.

  5. Inhibition of epithelial cell adhesion by retinoic acid. Relationship to reduced extracellular matrix production and alterations in Ca2+ levels.

    PubMed Central

    Varani, J.; Gibbs, D. F.; Inman, D. R.; Shah, B.; Fligiel, S. E.; Voorhees, J. J.

    1991-01-01

    Human squamous epithelial cells maintained in growth factor-deficient medium were examined for sensitivity to all-trans retinoic acid (retinoic acid). Under conditions of low external Ca2+ (0.15 mmol/l [millimolar]), or high external Ca2+ (1.4 mmol/l), retinoic acid stimulated proliferation. Concomitantly, cell-substrate adhesion was decreased. Enzyme-linked immunosorbent assays were used to assess production of two extracellular matrix components, ie, fibronectin and thrombospondin. In the presence of retinoic acid, production of both was decreased. Because both fibronectin and thrombospondin serve as epithelial cell adhesion factors, the decreased production of these moieties could contribute to reduced adhesion. Using 45Ca2+ to measure total cell-associated Ca2+ and the Ca2(+)-sensitive dye Indo-1 to measure intracellular free Ca2+, it was found that concentrations of retinoic acid that altered cell-substrate adhesion in the squamous epithelial cells had no effect on total, cell-associated Ca2+, but reduced intracellular free Ca2+ by 50% to 60%. Because Ca2+ is a regulator of adhesion, the ability of retinoic acid to modulate Ca2+ levels in the squamous epithelial cells may explain, in part, how retinoic acid influences their adhesiveness. Images Figure 1 PMID:2012176

  6. Neutrophil extracellular trap formation is increased in psoriasis and induces human β-defensin-2 production in epidermal keratinocytes.

    PubMed

    Hu, Stephen Chu-Sung; Yu, Hsin-Su; Yen, Feng-Lin; Lin, Chi-Ling; Chen, Gwo-Shing; Lan, Cheng-Che E

    2016-01-01

    Neutrophil extracellular traps (NETs) have been implicated in the development of certain immune-mediated diseases, but their role in psoriasis has not been clearly defined. Human β-defensin-2 (HBD-2) is an important antimicrobial peptide overexpressed in psoriasis epidermis. We evaluated whether the amount of NETs is increased in psoriasis and determined the effect of NETs on HBD-2 production in epidermal keratinocytes. Using fluorescent microscopy, we found that patients with psoriasis (n = 48) had higher amount of NETotic cells in their peripheral blood compared to healthy controls (n = 48) and patients with eczema (n = 35). Psoriasis sera showed increased ability to induce NET formation in control neutrophils but normal NET degradation ability. The amount of NETs in the peripheral blood correlated with psoriasis disease severity. NETosis was also observed in the majority (18 of 20) of psoriasis skin specimens. Furthermore, NETs induced HBD-2 mRNA and protein production in keratinocytes, and immunohistochemical analysis confirmed strong expression of HBD-2 in psoriasis lesional skin. In summary, NET formation is increased in peripheral blood and lesional skin of psoriasis patients and correlates with disease severity. Additionally, NET-induced HBD-2 production may provide a novel mechanism for the decreased susceptibility of psoriasis plaques to microbial infections. PMID:27493143

  7. Production and cytotoxicity of extracellular insoluble and droplets of soluble melanin by Streptomyces lusitanus DMZ-3.

    PubMed

    Madhusudhan, D N; Mazhari, Bi Bi Zainab; Dastager, Syed G; Agsar, Dayanand

    2014-01-01

    A Streptomyces lusitanus DMZ-3 strain with potential to synthesize both insoluble and soluble melanins was detected. Melanins are quite distinguished based on their solubility for varied biotechnological applications. The present investigation reveals the enhanced production of insoluble and soluble melanins in tyrosine medium by a single culture. Streptomyces lusitanus DMZ-3 was characterized by 16S rRNA gene analysis. An enhanced production of 5.29 g/L insoluble melanin was achieved in a submerged bioprocess following response surface methodology. Combined interactive effect of temperature (50°C), pH (8.5), tyrosine (2.0 g/L), and beef extract (0.5 g/L) were found to be critical variables for enhanced production in central composite design analysis. An optimized indigenous slant culture system was an innovative approach for the successful production (264 mg/L) of pure soluble melanin from the droplets formed on the surface of the culture. Both insoluble and soluble melanins were confirmed and characterized by Chemical, reactions, UV, FTIR, and TLC analysis. First time, cytotoxic study of melanin using brine shrimps was reported. Maximum cytotoxic activity of soluble melanin was Lc50-0.40 µg/mL and insoluble melanin was Lc50-0.80 µg/mL.

  8. Production and Cytotoxicity of Extracellular Insoluble and Droplets of Soluble Melanin by Streptomyces lusitanus DMZ-3

    PubMed Central

    Madhusudhan, D. N.; Mazhari, Bi Bi Zainab; Dastager, Syed G.

    2014-01-01

    A Streptomyces lusitanus DMZ-3 strain with potential to synthesize both insoluble and soluble melanins was detected. Melanins are quite distinguished based on their solubility for varied biotechnological applications. The present investigation reveals the enhanced production of insoluble and soluble melanins in tyrosine medium by a single culture. Streptomyces lusitanus DMZ-3 was characterized by 16S rRNA gene analysis. An enhanced production of 5.29 g/L insoluble melanin was achieved in a submerged bioprocess following response surface methodology. Combined interactive effect of temperature (50°C), pH (8.5), tyrosine (2.0 g/L), and beef extract (0.5 g/L) were found to be critical variables for enhanced production in central composite design analysis. An optimized indigenous slant culture system was an innovative approach for the successful production (264 mg/L) of pure soluble melanin from the droplets formed on the surface of the culture. Both insoluble and soluble melanins were confirmed and characterized by Chemical, reactions, UV, FTIR, and TLC analysis. First time, cytotoxic study of melanin using brine shrimps was reported. Maximum cytotoxic activity of soluble melanin was Lc50-0.40 µg/mL and insoluble melanin was Lc50-0.80 µg/mL. PMID:24839603

  9. Algal sensory photoreceptors.

    PubMed

    Hegemann, Peter

    2008-01-01

    Only five major types of sensory photoreceptors (BLUF-proteins, cryptochromes, phototropins, phytochromes, and rhodopsins) are used in nature to regulate developmental processes, photosynthesis, photoorientation, and control of the circadian clock. Sensory photoreceptors of algae and protists are exceptionally rich in structure and function; light-gated ion channels and photoactivated adenylate cyclases are unique examples. During the past ten years major progress has been made with respect to understanding the function, photochemistry, and structure of key sensory players of the algal kingdom.

  10. Life cycle environmental impacts of wastewater-based algal biofuels.

    PubMed

    Mu, Dongyan; Min, Min; Krohn, Brian; Mullins, Kimberley A; Ruan, Roger; Hill, Jason

    2014-10-01

    Recent research has proposed integrating wastewater treatment with algae cultivation as a way of producing algal biofuels at a commercial scale more sustainably. This study evaluates the environmental performance of wastewater-based algal biofuels with a well-to-wheel life cycle assessment (LCA). Production pathways examined include different nutrient sources (municipal wastewater influent to the activated sludge process, centrate from the sludge drying process, swine manure, and freshwater with synthetic fertilizers) combined with emerging biomass conversion technologies (microwave pyrolysis, combustion, wet lipid extraction, and hydrothermal liquefaction). Results show that the environmental performance of wastewater-based algal biofuels is generally better than freshwater-based algal biofuels, but depends on the characteristics of the wastewater and the conversion technologies. Of 16 pathways compared, only the centrate cultivation with wet lipid extraction pathway and the centrate cultivation with combustion pathway have lower impacts than petroleum diesel in all environmental categories examined (fossil fuel use, greenhouse gas emissions, eutrophication potential, and consumptive water use). The potential for large-scale implementation of centrate-based algal biofuel, however, is limited by availability of centrate. Thus, it is unlikely that algal biofuels can provide a large-scale and environmentally preferable alternative to petroleum transportation fuels without considerable improvement in current production technologies. Additionally, the cobenefit of wastewater-based algal biofuel production as an alternate means of treating various wastewaters should be further explored.

  11. Life cycle environmental impacts of wastewater-based algal biofuels.

    PubMed

    Mu, Dongyan; Min, Min; Krohn, Brian; Mullins, Kimberley A; Ruan, Roger; Hill, Jason

    2014-10-01

    Recent research has proposed integrating wastewater treatment with algae cultivation as a way of producing algal biofuels at a commercial scale more sustainably. This study evaluates the environmental performance of wastewater-based algal biofuels with a well-to-wheel life cycle assessment (LCA). Production pathways examined include different nutrient sources (municipal wastewater influent to the activated sludge process, centrate from the sludge drying process, swine manure, and freshwater with synthetic fertilizers) combined with emerging biomass conversion technologies (microwave pyrolysis, combustion, wet lipid extraction, and hydrothermal liquefaction). Results show that the environmental performance of wastewater-based algal biofuels is generally better than freshwater-based algal biofuels, but depends on the characteristics of the wastewater and the conversion technologies. Of 16 pathways compared, only the centrate cultivation with wet lipid extraction pathway and the centrate cultivation with combustion pathway have lower impacts than petroleum diesel in all environmental categories examined (fossil fuel use, greenhouse gas emissions, eutrophication potential, and consumptive water use). The potential for large-scale implementation of centrate-based algal biofuel, however, is limited by availability of centrate. Thus, it is unlikely that algal biofuels can provide a large-scale and environmentally preferable alternative to petroleum transportation fuels without considerable improvement in current production technologies. Additionally, the cobenefit of wastewater-based algal biofuel production as an alternate means of treating various wastewaters should be further explored. PMID:25220843

  12. Molecular Identification of a Newly Isolated Bacillus subtilis BI19 and Optimization of Production Conditions for Enhanced Production of Extracellular Amylase.

    PubMed

    Dash, Biplab Kumar; Rahman, M Mizanur; Sarker, Palash Kumar

    2015-01-01

    A study was carried out with a newly isolated bacterial strain yielding extracellular amylase. The phylogenetic tree constructed on the basis of 16S rDNA gene sequences revealed this strain as clustered with the closest members of Bacillus sp. and identified as Bacillus subtilis BI19. The effect of various fermentation conditions on amylase production through shake-flask culture was investigated. Rice flour (1.25%) as a cheap natural carbon source was found to induce amylase production mostly. A combination of peptone and tryptone as organic and ammonium sulfate as inorganic nitrogen sources gave highest yield. Maximum production was obtained after 24 h of incubation at 37 °C with an initial medium pH 8.0. Addition of surfactants like Tween 80 (0.25 g/L) and sodium lauryl sulfate (0.2 g/L) resulted in 28% and 15% increase in enzyme production, respectively. Amylase production was 3.06 times higher when optimized production conditions were used. Optimum reaction temperature and pH for crude amylase activity were 50 °C and 6.0, respectively. The crude enzyme showed activity and stability over a fair range of temperature and pH. These results suggest that B. subtilis BI19 could be exploited for production of amylase at relatively low cost and time. PMID:26180814

  13. Molecular Identification of a Newly Isolated Bacillus subtilis BI19 and Optimization of Production Conditions for Enhanced Production of Extracellular Amylase

    PubMed Central

    Dash, Biplab Kumar; Rahman, M. Mizanur; Sarker, Palash Kumar

    2015-01-01

    A study was carried out with a newly isolated bacterial strain yielding extracellular amylase. The phylogenetic tree constructed on the basis of 16S rDNA gene sequences revealed this strain as clustered with the closest members of Bacillus sp. and identified as Bacillus subtilis BI19. The effect of various fermentation conditions on amylase production through shake-flask culture was investigated. Rice flour (1.25%) as a cheap natural carbon source was found to induce amylase production mostly. A combination of peptone and tryptone as organic and ammonium sulfate as inorganic nitrogen sources gave highest yield. Maximum production was obtained after 24 h of incubation at 37°C with an initial medium pH 8.0. Addition of surfactants like Tween 80 (0.25 g/L) and sodium lauryl sulfate (0.2 g/L) resulted in 28% and 15% increase in enzyme production, respectively. Amylase production was 3.06 times higher when optimized production conditions were used. Optimum reaction temperature and pH for crude amylase activity were 50°C and 6.0, respectively. The crude enzyme showed activity and stability over a fair range of temperature and pH. These results suggest that B. subtilis BI19 could be exploited for production of amylase at relatively low cost and time. PMID:26180814

  14. Molecular Identification of a Newly Isolated Bacillus subtilis BI19 and Optimization of Production Conditions for Enhanced Production of Extracellular Amylase.

    PubMed

    Dash, Biplab Kumar; Rahman, M Mizanur; Sarker, Palash Kumar

    2015-01-01

    A study was carried out with a newly isolated bacterial strain yielding extracellular amylase. The phylogenetic tree constructed on the basis of 16S rDNA gene sequences revealed this strain as clustered with the closest members of Bacillus sp. and identified as Bacillus subtilis BI19. The effect of various fermentation conditions on amylase production through shake-flask culture was investigated. Rice flour (1.25%) as a cheap natural carbon source was found to induce amylase production mostly. A combination of peptone and tryptone as organic and ammonium sulfate as inorganic nitrogen sources gave highest yield. Maximum production was obtained after 24 h of incubation at 37 °C with an initial medium pH 8.0. Addition of surfactants like Tween 80 (0.25 g/L) and sodium lauryl sulfate (0.2 g/L) resulted in 28% and 15% increase in enzyme production, respectively. Amylase production was 3.06 times higher when optimized production conditions were used. Optimum reaction temperature and pH for crude amylase activity were 50 °C and 6.0, respectively. The crude enzyme showed activity and stability over a fair range of temperature and pH. These results suggest that B. subtilis BI19 could be exploited for production of amylase at relatively low cost and time.

  15. Production and characterization of a novel yeast extracellular invertase activity towards improved dibenzothiophene biodesulfurization.

    PubMed

    Arez, Bruno F; Alves, Luís; Paixão, Susana M

    2014-11-01

    The main goal of this work was the production and characterization of a novel invertase activity from Zygosaccharomyces bailii strain Talf1 for further application to biodesulfurization (BDS) in order to expand the exploitable alternative carbon sources to renewable sucrose-rich feedstock. The maximum invertase activity (163 U ml(-1)) was achieved after 7 days of Z. bailii strain Talf1 cultivation at pH 5.5-6.0, 25 °C, and 150 rpm in Yeast Malt Broth with 25 % Jerusalem artichoke pulp as inducer substrate. The optimum pH and temperature for the crude enzyme activity were 5.5 and 50 °C, respectively, and moreover, high stability was observed at 30 °C for pH 5.5-6.5. The application of Talf1 crude invertase extract (1 %) to a BDS process by Gordonia alkanivorans strain 1B at 30 °C and pH 7.5 was carried out through a simultaneous saccharification and fermentation (SSF) approach in which 10 g l(-1) sucrose and 250 μM dibenzothiophene were used as sole carbon and sulfur sources, respectively. Growth and desulfurization profiles were evaluated and compared with those of BDS without invertase addition. Despite its lower stability at pH 7.5 (loss of activity within 24 h), Talf1 invertase was able to catalyze the full hydrolysis of 10 g l(-1) sucrose in culture medium into invert sugar, contributing to a faster uptake of the monosaccharides by strain 1B during BDS. In SSF approach, the desulfurizing bacterium increased its μmax from 0.035 to 0.070 h(-1) and attained a 2-hydroxybiphenyl productivity of 5.80 μM/h in about 3 days instead of 7 days, corresponding to an improvement of 2.6-fold in relation to the productivity obtained in BDS process without invertase addition.

  16. Phytolacca americana inhibits the high glucose-induced mesangial proliferation via suppressing extracellular matrix accumulation and TGF-beta production.

    PubMed

    Jeong, Seung Il; Kim, Kang Ju; Choo, Yong Kug; Keum, Kyung Soo; Choi, Bong Kyu; Jung, Kyu Yong

    2004-02-01

    This study describes a potential of Phytolaccaceae (Phytolacca americana var.) as an inhibitor of high glucose-stimulated production of extracellular matrix (ECM) proteins and TGF-beta in cultured glomerular mesangial cells (GMCs). Raising the ambient glucose concentration for 24 hrs caused a dose-dependent increase in [3H]thymidine incorporation of GMCs, and the maximal response was achieved at 20 mM. Phytolaccaceae extracts (2.5-20 microg/ml) inhibited the high glucose-induced [3H]thymidine incorporation in a dose-dependent manner, and the concentrations tested here did not affect to the cell viability. Exposure of the GMCs to 20 mM glucose caused both ECM (collagen and fibronectin) accumulation and TGF-beta secretion, and these changes were significantly diminished by treatment of GMCs with Phytolaccaceae (10 microg/ml). Taken together, these results indicate that Phytolaccaceae inhibits the high glucose-induced GMCs proliferation partially through suppressing accumulation of ECM components and TGF-beta production, suggesting that Phytolaccaceae may be a promising agent for treating the development and progression of diabetic glomerulopathy.

  17. Analytical methods for soluble microbial products (SMP) and extracellular polymers (ECP) in wastewater treatment systems: a review.

    PubMed

    Kunacheva, Chinagarn; Stuckey, David C

    2014-09-15

    Effluents from biological processes contain a wide range of complex organic compounds, including soluble microbial products (SMP) and extracellular polymers (ECP), released during bacteria metabolism in mixed culture in bioreactors. It is important to clearly identify the primary components of SMPs and ECPs in order to understand the fundamental mechanisms of biological activity that create these compounds, and how to reduce these compounds in the effluent. In addition, these compounds constitute the main foulants in membrane bioreactors which are being used more widely around the world. A review on the extraction of ECP, characterization, and identification of SMPs and ECPs is presented, and we summarize up-to-date pretreatments and analytical methods for SMPs. Most researchers have focused more on the overall properties of SMPs and ECPs such as their concentrations, molecular weight distribution, aromaticity, hydrophobic and hydrophilic properties, biodegradability, and toxicity characteristics. Many studies on the identification of effluent SMPs show that most of these compounds were not present in the influent, such as humic acids, polysaccharides, proteins, nucleic acids, organic acids, amino acids, exocellular enzymes, structural components of cells and products of energy metabolism. A few groups of researchers have been working on the identification of compounds in SMPs using advanced analytical techniques such as GC-MS, LC-IT-TOF-MS and MALDI-TOF-MS. However, there is still considerably more work needed to be done analytically to fully understand the chemical characteristics of SMPs and ECPs.

  18. Extracellular amylase(s) production by fungi Botryodiplodia theobromae and Rhizopus oryzae grown on cassava starch residue.

    PubMed

    Ray, R C

    2004-10-01

    The fungi Botryodiplodia theobromae and Rhizopus oryzae produce extracellular amylase when grown on a liquid medium containing 2% (WN) soluble starch or cassava starch residue(CSR) (as starch equivalent), a waste generated after extraction of starch from cassava, as the sole carbon source. Using CSR as the sole carbon source, the highest amylase activity of 3.25 and 3.8 units (mg, glucose released x ml(-1) x h(-1)) were obtained in shake flask cultures during the late stationary phase of growth of B. theobromae and R. oryzae, respectively. These values were slightly lower than the values obtained using soluble starch as the carbon source. Maximum enzyme synthesis in CSR incorporated medium occurred at the growth temperature of 30 degrees C and pH 6.0. Presence of inorganic NH4+ salts like ammonium acetate and ammonium nitrate in culture medium yielded more amylase than the other nitrogen sources. Amylase(s) production in the controlled environment of a Table-Top glass Jar Fermenter (2-L capacity) was 4.8 and 5.1 units for B. theobromae and R. oryzae, respectively using CSR as the carbon substrate. It is concluded that CSR, a cheap agricultural waste obtained after starch extraction from cassava could replace soluble starch as carbon substrate for commercial production of fungal amylase(s).

  19. Heterotrophic bacterial production and extracellular enzymatic activity in sinking particulate matter in the western North Pacific Ocean.

    PubMed

    Yamada, Namiha; Fukuda, Hideki; Ogawa, Hiroshi; Saito, Hiroaki; Suzumura, Masahiro

    2012-01-01

    Heterotrophic activities on sinking particulate matter (SPM) play an important role in SPM fluxes in the ocean. To demonstrate regional differences in heterotrophic activities on SPM, we measured heterotrophic bacterial production (HBP) in seawater (HBP(SW)) and SPM (HBP(SPM)) as well as potential extracellular enzyme activity (EEA) in SPM on a transect along 155°E in the western North Pacific Ocean in the subarctic (44°N), the Kuroshio Extension area (35°N), and the subtropical gyre (20°N). Depth-integrated HBP(SW) from the surface to 500 m was comparable between the locations, whereas HBP(SPM) at 44°N was substantially lower than at the other sites. We found the highest particulate organic carbon (POC) export flux and export efficiency to bathypelagic depths, and the lowest water temperatures, at 44°N. We found significant correlations between leucine aminopeptidase (LAPase) activity, β-glucosidase (BGase) activity, POC flux and particulate organic nitrogen flux. LAPase activity was two orders of magnitude higher than BGase activity, with a BGase:LAPase activity ratio of 0.027. There were no significant correlations between HBP and EEA in SPM except for lipase, and lipase activity was significantly correlated with temperature. We propose that hydrographic conditions are an important factor controlling heterotrophic bacterial activity and export efficiency of organic carbon to the deep ocean, as are the sources and abundance of SPM produced in the euphotic zone via primary production. PMID:23109933

  20. High-level extracellular production of D-Psicose-3-epimerase with recombinant Escherichia coli by a two-stage glycerol feeding approach.

    PubMed

    Gu, Lei; Zhang, Juan; Liu, Baihong; Wu, Chongde; Du, Guocheng; Chen, Jian

    2013-11-01

    The aim of this study is to achieve high-level extracellular production of D-Psicose-3-epimerase (DPE) with recombinant Escherichia coli. High-level production of DPE is one of the key factors in D-Psicose production. In the present study, the gene AAL45544.1 from Agrobacterium tumefaciens str. C58 was modified by artificial synthesis for overexpression in E. coli. The total DPE activity reached 3.96 U mL(-1) after optimization of the media composition, induction temperature, and concentration of inducer. Furthermore, it was found that addition of glycine had a positive effect on the extracellular production of DPE, which reached 3.5 U mL(-1). Finally, a two-stage glycerol feeding strategy based on both the specific growth rate before induction and the amount of glycerol residues after induction was applied in a 3-L fermenter. After a series of optimal strategies in the 3-L fermenter, the total and extracellular DPE activity were 5.08- and 3.11-fold higher than that noted in the shake flask. The extracellular and intracellular DPE activity reached 10.9 and 13.2 U mL(-1), achieving 25.5 and 31.1 % conversion of D-fructose to D-psicose, respectively. The systemic strategies presented in this study provide valuable novel information for the industrial application of DPE.

  1. An efficient protocol to enhance the extracellular production of recombinant protein from Escherichia coli by the synergistic effects of sucrose, glycine, and Triton X-100.

    PubMed

    Bao, Ru-Meng; Yang, Hong-Ming; Yu, Chang-Mei; Zhang, Wei-Fen; Tang, Jin-Bao

    2016-10-01

    Targeting recombinant proteins at highly extracellular production in the culture medium of Escherichia coli presents a significant advantage over cytoplasmic or periplasmic expression. In this work, a recombinant protein between ZZ protein and alkaline phosphatase (rZZ-AP) was constructed. Because rZZ-AP has the IgG-binding capacity and enzymatic activity, it can serve as an immunoreagent in immunoassays. However, only a very small portion of rZZ-AP is generally secreted into the aqueous medium under conventional cultivation procedure. Hence, we emphasized on the optimization of the culture procedures and attempted to dramatically enhance the yield of extracellular rZZ-AP from E. coli HB101 host cells by adding sucrose, glycine, and Triton X-100 in the culture medium. Results showed that the extracellular production of rZZ-AP in the culture medium containing 5% sucrose, 1% glycine, and 1% Triton X-100 was 18.6 mg/l, which was 18.6-fold higher than that without the three chemicals. And the β-galactosidase activity test showed that the increased extracellular rZZ-AP was not due to cell lysis. Further analysis suggested a significant interaction effect among the three chemicals for the enhancement of extracellular production. Ultrastructural analysis indicated that the enhancement may be due to the influence of sucrose, glycine, and Triton X-100 on the periplasmic osmolality, permeability, or integrity of the cell wall, respectively. This proposed approach presents a simple strategy to enhance the extracellular secretion of recombinant proteins in the E. coli system at the process of cell cultivation.

  2. Regulation of extracellular polygalacturonase production in Pseudomonas solanacearum. Progress report, [May 1, 1992--April 30, 1994

    SciTech Connect

    Allen, C.

    1994-06-01

    Pseudomonas solanacearum is an economically important plant pathogen that causes bacterial wilt disease of diverse crops. The bacterium produces at least three isozymes of polygalacturonase, which degrade plant cell walls and contribute substantially to bacterial wilt disease development. The central objective of this research project is to determine how expression of these enzymes is regulated. To this end, we isolated a positive trans-acting regulator of polygalacturonase production (pehR). We have focused on further characterization of the pehR mutant pheonotype, and studies of pehR expression. Preliminary results suggest pehR also regulates bacterial motility. An investigation of two unusual tyrosine phosphoproteins in P. solanacearum is also described.

  3. Production of Extracellular Laccase from Bacillus subtilis MTCC 2414 Using Agroresidues as a Potential Substrate

    PubMed Central

    Muthukumarasamy, Narayanan P.; Jackson, Beenie; Joseph Raj, Antony; Sevanan, Murugan

    2015-01-01

    Laccases are the model enzymes for multicopper oxidases and participate in several applications such as bioremediation, biopulping, textile, and food industries. Laccase producing bacterium, Bacillus subtilis MTCC 2414, was subjected to optimization by conventional techniques and was partially purified using ammonium salt precipitation method. The agroresidue substrates used for higher yield of laccase were rice bran and wheat bran. Maximum production was achieved at temperature 30°C (270 ± 2.78 U/mL), pH 7.0 (345 ± 3.14 U/mL), and 96 h (267 ± 2.64 U/mL) of incubation. The carbon and nitrogen sources resulted in high enzyme yield at 3% sucrose (275 ± 3.11 U/mL) and 3% peptone (352.2 ± 4.32 U/mL) for rice bran and 3% sucrose (247.4 ± 3.51 U/mL) and 3% peptone (328 ± 3.33 U/mL) for wheat bran, respectively. The molecular weights of partially purified laccase were 52 kDa for rice bran and 55 kDa for wheat bran. The laccase exhibited optimal activity at 70°C (260.3 ± 6.15 U/mL), pH 9.0 (266 ± 4.02 U/mL), and metal ion CuSO4 (141.4 ± 6.64) was found to increase the production. This is the first report that delivers the higher yield of laccase produced from B. subtilis MTCC 2414 using agroresidues as a potential substrate. PMID:26451255

  4. Production of Extracellular Laccase from Bacillus subtilis MTCC 2414 Using Agroresidues as a Potential Substrate.

    PubMed

    Muthukumarasamy, Narayanan P; Jackson, Beenie; Joseph Raj, Antony; Sevanan, Murugan

    2015-01-01

    Laccases are the model enzymes for multicopper oxidases and participate in several applications such as bioremediation, biopulping, textile, and food industries. Laccase producing bacterium, Bacillus subtilis MTCC 2414, was subjected to optimization by conventional techniques and was partially purified using ammonium salt precipitation method. The agroresidue substrates used for higher yield of laccase were rice bran and wheat bran. Maximum production was achieved at temperature 30°C (270 ± 2.78 U/mL), pH 7.0 (345 ± 3.14 U/mL), and 96 h (267 ± 2.64 U/mL) of incubation. The carbon and nitrogen sources resulted in high enzyme yield at 3% sucrose (275 ± 3.11 U/mL) and 3% peptone (352.2 ± 4.32 U/mL) for rice bran and 3% sucrose (247.4 ± 3.51 U/mL) and 3% peptone (328 ± 3.33 U/mL) for wheat bran, respectively. The molecular weights of partially purified laccase were 52 kDa for rice bran and 55 kDa for wheat bran. The laccase exhibited optimal activity at 70°C (260.3 ± 6.15 U/mL), pH 9.0 (266 ± 4.02 U/mL), and metal ion CuSO4 (141.4 ± 6.64) was found to increase the production. This is the first report that delivers the higher yield of laccase produced from B. subtilis MTCC 2414 using agroresidues as a potential substrate. PMID:26451255

  5. Isolation and identification of actinomycetes for production of novel extracellular glutaminase free L-asparaginase.

    PubMed

    Saxena, Akansha; Upadhyay, Ramraj; Kango, Naveen

    2015-12-01

    Over the recent years glutaminase free L-asparaginase has gained more importance due to better therapeutic properties for treatment of acute lymphoblastic leukemia. Actinomycetes are known for L-asparaginase activity. In the current study, 80 actinomycetes were isolated from various soil habitats by serial dilution technique. Presence of L-asparaginase was investigated in a total of 240 actinomycetes by tubed agar method using modified M-9 medium. A total of 165 actinomycetes were found positive for L-asparaginase activity. Among these, 57 actinomycetes producing larger zones of L-asparagine hydrolysis were further screened for their capacity to produce glutaminase-free L-asparaginase. Four L-glutaminase-free actinomycetes were found to be potential L-asparaginase producers. These actinomycetes were identified as Streptomyces cyaneus (SAP 1287, CFS 1560), S. exfoliates (CFS 1557) and S. phaeochromogenes (GS 1573) on the basis of morphological and biochemical identification studies. Maximum L-asparaginase activity (19.2 Uml(-1)) was observed in culture filtrate of S. phaeochromogenes under submerged fermentation. Results indicate that S. phaeochromogenes could be a potential source of glutaminase free L-asparaginase for commercial purpose. To the best of our knowledge, this is the first report on production of glutaminase free L-asparaginase from S. cyaneus, S. exfoliatus and S. phaeochromogenes. PMID:26742323

  6. Extracellular bio-production and characterization of small monodispersed CdSe quantum dot nanocrystallites

    NASA Astrophysics Data System (ADS)

    Suresh, Anil K.

    2014-09-01

    Engineered nanoparticles of diverse forms are being profoundly used for various applications and demand ecologically benign synthesis processes. Conventional chemical methods employed for the syntheses of nanoparticles are environmentally unfriendly and energy intensive. Biologically inspired biofabrication approaches that utilize naturally existing microorganisms or plant extracts or biomaterials might overcome these issues. The present investigation for the first time shows the synthesis of small and monodispersed cadmium selenide nanoparticles utilizing the plant pathogenic fungus, Helminthosporum solani upon incubating with an aqueous solution of CdCl2 and SeCl4 under ambient conditions. Multiple physical characterizations involving ultraviolet-visible and photoluminescence spectroscopy, transmission electron microscopy, selected area electron diffraction and X-ray photoelectron spectroscopy confirmed the production, purity, optical and surface characteristics, crystalline nature, size and shape distributions, and elemental composition of the nanoparticles. Pluralities of the particles are monodisperse spheres with a mean diameter of 5.5 ± 2 nm, are hydrophilic, highly stable with a broad photoluminescence and 1% quantum yield. This approach provides an alternative facile route for the biofabrication of quantum dot that is reliable, environmentally friendly, and lends itself directly for the creation of fluorescent biological labels.

  7. Extracellular production of riboflavin-binding protein, a potential bitter inhibitor, by Brevibacillus choshinensis.

    PubMed

    Maehashi, Kenji; Matano, Mami; Saito, Makiko; Udaka, Shigezo

    2010-05-01

    Riboflavin-binding protein (RBP) is a glycophosphoprotein found in hen eggs. We previously identified the extraordinary characteristic of RBP in reducing bitterness. For a more detailed study on the mode of action and industrial application of this characteristic, we investigated the microbial production of recombinant RBP (rRBP). We constructed a chicken RBP gene expression vector by inserting the RBP cDNA in pNCMO2, the Escherichia coli-Brevibacillus choshinensis shuttle vector. B. choshinensis HPD31 transformants produced 0.8g/l of processed and unglycosylated RBP in a soluble form in the culture supernatant. However, the expressed RBP was partially dimerized and monomeric RBP was purified by two step anion-exchange and gel-filtration chromatographies. The purified rRBP elicited bitterness reduction against quinine and caffeine, although it largely lost its riboflavin-binding ability. These results indicated that glycosylation and riboflavin-binding ability are not essential for the bitterness reduction of RBP. In addition, we assessed the usefulness of the Brevibacillus system for the expression and secretion of RBP as a new type of bitterness inhibitor. PMID:20045733

  8. Production of extracellular biopolymers and identification of intracellular proteins and Rhizobium tropici.

    PubMed

    Oliveira, José; Figueiredo, Marcia; Silva, Marcia; Malta, Marília; Vendruscolo, Claire; Almeida, Hélio

    2012-12-01

    The objective of this study was to identify species of rhizobia (from the IPA 403 and IPA 49 isolates), to assess the physico-chemical characteristics of the biopolymers produced by these rhizobia and to determine the soluble intracellular proteins that are present in these rhizobia. The polysaccharides containing acetyl and pyruvic acid groups that were produced by different strains that had been cultivated in yeast extract mannitol (YEM) medium for 132, 144, and 168 h were evaluated for yield, viscosity, and concentration. Based on the analysis of their partial 16S rDNA sequences, both isolates were identified as Rhizobium tropici. The polymers produced in liquid YEM medium were recovered, dried and weighed to determine culture yield. Soluble intracellular proteins were identified through the techniques of 2D-PAGE and mass spectrometry for cultures that were cultivated for 168 h. The largest biopolymer yield and the highest viscosity and concentration of acetyl and pyruvic acids were obtained from the IPA 403 isolate after 168 h of culture. The proteins that were identified for the CIAT 899 isolate included elongation factor TU, a chaperone; GroE/GroEs and a putative glycosyltransferase, all of which catalyze the production of polysaccharides. For the IPA 403 strain, dinitrogenase and nitrogenase iron proteins were found. In the IPA 49 strain, glyceraldehyde-3-phosphate dehydrogenase was found along with two other proteins, the beta subunit of an electron-transferring flavoprotein and a dehydrogenase.

  9. Extracellular polysaccharides from Ascomycota and Basidiomycota: production conditions, biochemical characteristics, and biological properties.

    PubMed

    Osińska-Jaroszuk, Monika; Jarosz-Wilkołazka, Anna; Jaroszuk-Ściseł, Jolanta; Szałapata, Katarzyna; Nowak, Artur; Jaszek, Magdalena; Ozimek, Ewa; Majewska, Małgorzata

    2015-12-01

    Fungal polysaccharides (PSs) are the subject of research in many fields of science and industry. Many properties of PSs have already been confirmed and the list of postulated functions continues to grow. Fungal PSs are classified into different groups according to systematic affinity, structure (linear and branched), sugar composition (homo- and heteropolysaccharides), type of bonds between the monomers (β-(1 → 3), β-(1 → 6), and α-(1 → 3)) and their location in the cell (cell wall PSs, exoPSs, and endoPSs). Exopolysaccharides (EPSs) are most frequently studied fungal PSs but their definition, classification, and origin are still not clear and should be explained. Ascomycota and Basidiomycota fungi producing EPS have different ecological positions (saprotrophic and endophytic, pathogenic or symbiotic-mycorrhizae fungi); therefore, EPSs play different biological functions, for example in the protection against environmental stress factors and in interactions with other organisms. EPSs obtained from Ascomycota and Basidiomycota fungal cultures are known for their antioxidant, immunostimulating, antitumor, and antimicrobial properties. The major objective of the presented review article was to provide a detailed description of the state-of-the-art knowledge of the effectiveness of EPS production by filamentous and yeast Ascomycota and Basidiomycota fungi and techniques of derivation of EPSs, their biochemical characteristics, and biological properties allowing comprehensive analysis as well as indication of similarities and differences between these fungal groups. Understanding the role of EPSs in a variety of processes and their application in food or pharmaceutical industries requires improvement of the techniques of their derivation, purification, and characterization. The detailed analyses of data concerning the derivation and application of Ascomycota and Basidiomycota EPSs can facilitate development and trace the direction of application of these EPSs

  10. Large strain stimulation promotes extracellular matrix production and stiffness in an elastomeric scaffold model.

    PubMed

    D׳Amore, Antonio; Soares, Joao S; Stella, John A; Zhang, Will; Amoroso, Nicholas J; Mayer, John E; Wagner, William R; Sacks, Michael S

    2016-09-01

    Mechanical conditioning of engineered tissue constructs is widely recognized as one of the most relevant methods to enhance tissue accretion and microstructure, leading to improved mechanical behaviors. The understanding of the underlying mechanisms remains rather limited, restricting the development of in silico models of these phenomena, and the translation of engineered tissues into clinical application. In the present study, we examined the role of large strip-biaxial strains (up to 50%) on ECM synthesis by vascular smooth muscle cells (VSMCs) micro-integrated into electrospun polyester urethane urea (PEUU) constructs over the course of 3 weeks. Experimental results indicated that VSMC biosynthetic behavior was quite sensitive to tissue strain maximum level, and that collagen was the primary ECM component synthesized. Moreover, we found that while a 30% peak strain level achieved maximum ECM synthesis rate, further increases in strain level lead to a reduction in ECM biosynthesis. Subsequent mechanical analysis of the formed collagen fiber network was performed by removing the scaffold mechanical responses using a strain-energy based approach, showing that the denovo collagen also demonstrated mechanical behaviors substantially better than previously obtained with small strain training and comparable to mature collagenous tissues. We conclude that the application of large deformations can play a critical role not only in the quantity of ECM synthesis (i.e. the rate of mass production), but also on the modulation of the stiffness of the newly formed ECM constituents. The improved understanding of the process of growth and development of ECM in these mechano-sensitive cell-scaffold systems will lead to more rational design and manufacturing of engineered tissues operating under highly demanding mechanical environments.

  11. Large strain stimulation promotes extracellular matrix production and stiffness in an elastomeric scaffold model.

    PubMed

    D׳Amore, Antonio; Soares, Joao S; Stella, John A; Zhang, Will; Amoroso, Nicholas J; Mayer, John E; Wagner, William R; Sacks, Michael S

    2016-09-01

    Mechanical conditioning of engineered tissue constructs is widely recognized as one of the most relevant methods to enhance tissue accretion and microstructure, leading to improved mechanical behaviors. The understanding of the underlying mechanisms remains rather limited, restricting the development of in silico models of these phenomena, and the translation of engineered tissues into clinical application. In the present study, we examined the role of large strip-biaxial strains (up to 50%) on ECM synthesis by vascular smooth muscle cells (VSMCs) micro-integrated into electrospun polyester urethane urea (PEUU) constructs over the course of 3 weeks. Experimental results indicated that VSMC biosynthetic behavior was quite sensitive to tissue strain maximum level, and that collagen was the primary ECM component synthesized. Moreover, we found that while a 30% peak strain level achieved maximum ECM synthesis rate, further increases in strain level lead to a reduction in ECM biosynthesis. Subsequent mechanical analysis of the formed collagen fiber network was performed by removing the scaffold mechanical responses using a strain-energy based approach, showing that the denovo collagen also demonstrated mechanical behaviors substantially better than previously obtained with small strain training and comparable to mature collagenous tissues. We conclude that the application of large deformations can play a critical role not only in the quantity of ECM synthesis (i.e. the rate of mass production), but also on the modulation of the stiffness of the newly formed ECM constituents. The improved understanding of the process of growth and development of ECM in these mechano-sensitive cell-scaffold systems will lead to more rational design and manufacturing of engineered tissues operating under highly demanding mechanical environments. PMID:27344402

  12. Production of an extracellular alkaline metalloprotease from a newly isolated, moderately halophile, Salinivibrio sp. strain AF-2004.

    PubMed

    Ali Amoozegar, Mohammad; Zahra Fatemi, Azadeh; Reza Karbalaei-Heidari, Hamid; Reza Razavi, Mohamad

    2007-01-01

    An extracellular protease was produced under stress conditions of high temperature and high salinity by a newly isolated moderate halophile, Salinivibrio sp. strain AF-2004 in a basal medium containing peptone, beef extract, glucose and NaCl. A modification of Kunitz method was used for protease assay. The isolate was capable of producing protease in the presence of sodium chloride, sodium sulfate, sodium nitrate, sodium nitrite, potassium chloride, sodium acetate and sodium citrate. The maximum protease was secreted in the presence of 7.5 to 10% (w/v) sodium sulfate or 3% (w/v) sodium acetate (4.6 U ml(-1)). Various carbon sources including glucose, lactose, casein and peptone were capable of inducing enzyme production. The optimum pH, temperature and aeration for enzyme production were 9.0, 32 degrees C and 220 rpm, respectively. The enzyme production corresponded with growth and reached a maximum level during the mid-stationary phase. Maximum protease activity was exhibited in the medium containing 1% (w/v) NaCl at 60 degrees C, with 18% and 41% activity reductions at temperature 50 and 70 degrees C, respectively. The optimum pH for enzyme activity was 8.5, with 86% and 75% residual activities at pH 10 and 6, respectively. The activity of enzyme was inhibited by EDTA. These results suggest that the protease secreted by Salinivibrio sp. strain AF-2004 is industrially important from the perspectives of its activity at a broad pH ranges (5.0-10.0), its moderate thermoactivity in addition to its high tolerance to a wide range of salt concentration (0-10% NaCl).

  13. Influence of hydrogel mechanical properties and mesh size on vocal fold fibroblast extracellular matrix production and phenotype

    PubMed Central

    Hahn, Mariah S.; Liao, Huimin; Munoz-Pinto, Dany; Qu, Xin; Hou, Yaping; Grunlan, Melissa A.

    2008-01-01

    Current clinical management of vocal fold (VF) scarring produces inconsistent and often suboptimal results. Researchers are investigating a number of alternative treatments for VF lamina propria (LP) scarring, including designer implant materials for functional LP regeneration. In the present study, we investigate the effects of the initial scaffold elastic modulus and mesh size on encapsulated VF fibroblast (VFF) extracellular matrix (ECM) production toward rational scaffold design. Polyethylene glycol diacrylate (PEGDA) hydrogels were selected for this study since their material properties, including mechanical properties, mesh size, degradation rate and bioactivity, can be tightly controlled and systematically modified. Porcine VFF were encapsulated in four PEGDA hydrogels with degradation half lives of ~25 days and initial elastic compressive moduli ranging from ~30 to 100 kPa and initial mesh sizes ranging from ~9 to 27 nm. After 30 days of static culture, VFF ECM production and phenotype in each formulation was assessed biochemically and histologically. Sulfated glycosaminoglycan synthesis increased in similar degree with both increasing initial modulus and decreasing initial mesh size. In contrast, elastin production decreased with increasing initial modulus but increased with decreasing initial mesh size. Both collagen deposition and the induction of a myofibroblastic phenotype depended strongly on initial mesh size but appeared largely unaffected by variations in initial modulus. The present results indicate that scaffold mesh size warrants further investigation as a critical regulator of VFF ECM synthesis. Furthermore, this study validates a systematic and controlled approach for analyzing VFF response to scaffold properties, which should aid in rational scaffold selection/design. PMID:18515199

  14. N-acetyl-L-cysteine affects growth, extracellular polysaccharide production, and bacterial biofilm formation on solid surfaces.

    PubMed

    Olofsson, Ann-Cathrin; Hermansson, Malte; Elwing, Hans

    2003-08-01

    N-Acetyl-L-cysteine (NAC) is used in medical treatment of patients with chronic bronchitis. The positive effects of NAC treatment have primarily been attributed to the mucus-dissolving properties of NAC, as well as its ability to decrease biofilm formation, which reduces bacterial infections. Our results suggest that NAC also may be an interesting candidate for use as an agent to reduce and prevent biofilm formation on stainless steel surfaces in environments typical of paper mill plants. Using 10 different bacterial strains isolated from a paper mill, we found that the mode of action of NAC is chemical, as well as biological, in the case of bacterial adhesion to stainless steel surfaces. The initial adhesion of bacteria is dependent on the wettability of the substratum. NAC was shown to bind to stainless steel, increasing the wettability of the surface. Moreover, NAC decreased bacterial adhesion and even detached bacteria that were adhering to stainless steel surfaces. Growth of various bacteria, as monocultures or in a multispecies community, was inhibited at different concentrations of NAC. We also found that there was no detectable degradation of extracellular polysaccharides (EPS) by NAC, indicating that NAC reduced the production of EPS, in most bacteria tested, even at concentrations at which growth was not affected. Altogether, the presence of NAC changes the texture of the biofilm formed and makes NAC an interesting candidate for use as a general inhibitor of formation of bacterial biofilms on stainless steel surfaces. PMID:12902275

  15. N-acetyl-L-cysteine affects growth, extracellular polysaccharide production, and bacterial biofilm formation on solid surfaces.

    PubMed

    Olofsson, Ann-Cathrin; Hermansson, Malte; Elwing, Hans

    2003-08-01

    N-Acetyl-L-cysteine (NAC) is used in medical treatment of patients with chronic bronchitis. The positive effects of NAC treatment have primarily been attributed to the mucus-dissolving properties of NAC, as well as its ability to decrease biofilm formation, which reduces bacterial infections. Our results suggest that NAC also may be an interesting candidate for use as an agent to reduce and prevent biofilm formation on stainless steel surfaces in environments typical of paper mill plants. Using 10 different bacterial strains isolated from a paper mill, we found that the mode of action of NAC is chemical, as well as biological, in the case of bacterial adhesion to stainless steel surfaces. The initial adhesion of bacteria is dependent on the wettability of the substratum. NAC was shown to bind to stainless steel, increasing the wettability of the surface. Moreover, NAC decreased bacterial adhesion and even detached bacteria that were adhering to stainless steel surfaces. Growth of various bacteria, as monocultures or in a multispecies community, was inhibited at different concentrations of NAC. We also found that there was no detectable degradation of extracellular polysaccharides (EPS) by NAC, indicating that NAC reduced the production of EPS, in most bacteria tested, even at concentrations at which growth was not affected. Altogether, the presence of NAC changes the texture of the biofilm formed and makes NAC an interesting candidate for use as a general inhibitor of formation of bacterial biofilms on stainless steel surfaces.

  16. The characteristics of extracellular polymeric substances and soluble microbial products in moving bed biofilm reactor-membrane bioreactor.

    PubMed

    Duan, Liang; Jiang, Wei; Song, Yonghui; Xia, Siqing; Hermanowicz, Slawomir W

    2013-11-01

    The characteristics of extracellular polymeric substances (EPS) and soluble microbial products (SMP) in conventional membrane bioreactor (MBR) and in moving bed biofilm reactor-membrane bioreactors (MBBR-MBR) were investigated in long-term (170 days) experiments. The results showed that all reactors had high removal efficiency of ammonium and COD, despite very different fouling conditions. The MBBR-MBR with media fill ratio of 26.7% had much lower total membrane resistance and no obvious fouling were detected during the whole operation. In contrast, MBR and MBBR-MBR with lower and higher media fill experienced more significant fouling. Low fouling at optimum fill ratio may be due to the higher percentage of small molecular size (<1 kDa) and lower percentage of large molecular size (>100 kDa) of EPS and SMP in the reactor. The composition of EPS and SMP affected fouling due to different O-H bonds in hydroxyl functional groups, and less polysaccharides and lipids.

  17. Extracellular production of Streptomyces exfoliatus poly(3-hydroxybutyrate) depolymerase in Rhodococcus sp. T104: determination of optimal biocatalyst conditions.

    PubMed

    García-Hidalgo, Javier; Hormigo, Daniel; Prieto, María Auxiliadora; Arroyo, Miguel; de la Mata, Isabel

    2012-03-01

    The phaZ ( Sex ) gene encoding poly(3-hydroxybutyrate) depolymerase from Streptomyces exfoliatus has been successfully cloned and expressed in Rhodococcus sp. T104 for the first time. Likewise, the recombinant enzyme was efficiently produced as an extracellular active form and purified to homogeneity by two hydrophobic chromatographic steps. MALDI-TOF analysis showed that the native enzyme is a monomer. Circular dichroism studies have revealed a secondary structure showing 25.6% α-helix, 21.4% β-sheet, 17.1% β-turns, and 35.2% random coil, with a midpoint transition temperature (T (m)) of 55.8 °C. Magnesium and calcium ions enhanced the enzyme activity, whereas manganese inhibited it. EDTA moderately decreased the activity, and the enzyme was completely deactivated at 3 M NaCl. Chemical modification studies indicated the presence of the catalytic triad serine-histidine-carboxylic acid in the active site. High-performance liquid chromatography (HPLC)-mass spectrometry (MS) analysis of PHB products of enzymatic hydrolysis showed monomers and dimers of 3-hydroxybutyric acid, demonstrating that PHB depolymerase is an exo-hydrolase. Addition of methyl-β-cyclodextrin simultaneously increased the activity as well as preserved the enzyme during lyophilization. Finally, thermoinactivation studies showed that the enzyme is highly stable at 40 °C. All these features support the potential industrial application of this recombinant enzyme in the production of (R)-3-hydroxyalkanoic acid derivatives as well as in the degradation of bioplastics. PMID:21845385

  18. Extracellular polymeric substances production kinetics of 13 sludge isolates using wastewater sludge as raw material and its flocculation potential.

    PubMed

    More, Tanaji; Mahmoudi, Amine; Yan, Song; Tyagi, Rajeshwar Dayal

    2015-01-01

    The kinetics of batch fermentation of 13 extracellular polymeric substances (EPS) producing bacterial strains (9 Bacillus, 2 Serratia and 2 Yersinia) were carried out using sterilized sludge as a raw material. The most of Bacillus (µ(max): 0.11-0.27 h⁻¹), Serratia (µ(max): 0.23-0.27 h⁻¹) and Yersinia (µ(max): 0.18-0.19 h⁻¹) strains had capability to grow and produce EPS (1.36-2.12 g/L) in the sterilized sludge. In general, EPS production was mixed growth associated for all the bacterial strains cultivated independently. Bacillus sp. 7, Serratia sp. 2 and Yersinia sp. 2 produced higher concentration (1.95-2.12 g/L) of EPS than the other remaining bacterial strains. Protein and carbohydrate contents of EPS remained constant during fermentation. Broth EPS (B-EPS) exhibited high kaolin flocculation activity (≥ 75%) in most of the cases except Bacillus sp. 1, Bacillus sp. 5 and Bacillus sp. 9, respectively. In general, high flocculation activities (FAs) (≥ 75%), were attained using 1.31-1.70 mg B-EPS/g kaolin, 0.45-0.97 mg protein/g kaolin and 0.11-0.21 mg carbohydrates/g kaolin. The study suggests that further systematic exploration is required for optimizing the process of EPS production. EPS produced in the sludge can potentially be used for different water and wastewater treatments.

  19. Bacteria associated with obstructive pulmonary disease elaborate extracellular products that stimulate mucin secretion by explants of guinea pig airways.

    PubMed Central

    Adler, K. B.; Hendley, D. D.; Davis, G. S.

    1986-01-01

    Certain cell-free filtrates from broth cultures of Pseudomonas aeruginosa, Hemophilus influenzae and Streptococcus pneumoniae stimulate secretion of glycoconjugates by explants of guinea pig trachea. The stimulatory effect is not related to toxicity or damage to the respiratory mucosa, as well as could be determined by ultrastructural examination of the explants after exposure. Bacteria isolated from patients with a history of chronic obstructive lung disease (P aeruginosa from cystic fibrosis, H influenzae, and S pneumoniae from chronic bronchitis) do not demonstrate increased frequency of positive strains or greater stimulation of secretion than organisms isolated from other individuals. At least three stimulatory substances are found in cell-free filtrates of P aeruginosa. They appear to be proteins of molecular weight 60,000-100,000 as determined by gel filtration. Within the crude filtrate, they are relatively stable to heat, proteolysis, and storage at 4 C and in liquid nitrogen. The stimulatory activity is not lost upon subculture of the bacteria. When isolated from the filtrate by column chromatography, they become labile to heat and trypsin. Isolated active fractions show proteolytic activity coinciding with mucin-stimulating capacity, suggesting a relationship with Pseudomonas proteases. Stimulatory substances released by S pneumoniae and H influenzae appear to be different from those elaborated by Pseudomonas. They are extremely labile to heat and storage, and the capacity to stimulate secretion is lost on subculture. Preliminary gel filtration indicates the S pneumoniae stimulatory substance(s) is in a molecular weight range of 100,000-300,000 daltons, while that of H influenzae is between 50,000 and 200,000. The results suggest bacteria which chronically infect or colonize respiratory airways of individuals suffering from obstructive lung disease can elaborate extracellular product(s) capable of stimulating secretion of mucin. Thus, the bacteria

  20. Bioprocess development for extracellular production of recombinant human interleukin-3 (hIL-3) in Pichia pastoris.

    PubMed

    Dagar, Vikas Kumar; Adivitiya; Devi, Nirmala; Khasa, Yogender Pal

    2016-10-01

    Human interleukin-3 (hIL-3) is a therapeutically important cytokine involved in the maturation and differentiation of various cells of the immune system. The codon-optimized hIL-3 gene was cloned in fusion with the N-terminus α-mating factor signal peptide of Saccharomyces cerevisiae under an inducible alcohol oxidase 1 (AOX1) and constitutive glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter. A Zeocin concentration up to 2000 mg/L was used to select hyper-producers. The shake flask cultivation studies in the Pichia pastoris GS115 host resulted a maximum recombinant hIL-3 expression level of 145 mg/L in the extracellular medium under the control of AOX1 promoter. The batch fermentation strategy allowed us to attain a fairly pure glycosylated hIL-3 protein in the culture supernatant at a final concentration of 475 mg/L with a high volumetric productivity of 4.39 mg/L/h. The volumetric product concentration achieved at bioreactor level was 3.28 folds greater than the shake flask results. The 6x His-tagged protein was purified using Ni-NTA affinity chromatography and confirmed further by western blot analysis using anti-6x His tag antibody. The glycosylation of recombinant hIL-3 protein was confirmed in a PNGase F deglycosylation reaction where it showed a molecular weight band pattern similar to E. coli produced non-glycosylated hIL-3 protein. The structural properties of recombinant hIL-3 protein were confirmed by CD and fluorescence spectroscopy where protein showed 40 % α-helix, 12 % β-sheets with an emission maxima at 343 nm. MALDI-TOF-TOF analysis was used to establish the protein identity. The biological activity of purified protein was confirmed by the human erythroleukemia TF-1 cell proliferation assay.

  1. Extracellular glucose supports lactate production but not aerobic metabolism in cardiomyocytes from both normoglycemic Atlantic cod and low glycemic short-horned sculpin.

    PubMed

    Clow, Kathy A; Short, Connie E; Driedzic, William R

    2016-05-01

    Fish exhibit a wide range of species-specific blood glucose levels. How this relates to glucose utilization is yet to be fully realized. Here, we assessed glucose transport and metabolism in myocytes isolated from Atlantic cod (Gadus morhua) and short-horned sculpin (Myoxocephalus scorpius), species with blood glucose levels of 3.7 and 0.57 mmol l(-1), respectively. Glucose metabolism was assessed by the production of (3)H2O from [2-(3)H]glucose. Glucose metabolism was 3.5- to 6-fold higher by myocytes from Atlantic cod than by those from short-horned sculpin at the same level of extracellular glucose. In Atlantic cod myocytes, glucose metabolism displayed what appears to be a saturable component with respect to extracellular glucose, and cytochalasin B inhibited glucose metabolism. These features revealed a facilitated glucose diffusion mechanism that accounts for between 30% and 55% of glucose entry at physiological levels of extracellular glucose. Facilitated glucose diffusion appears to be minimal in myocytes for short-horned sculpin. Glucose entry by simple diffusion occurs in both cell types with the same linear relationship between glucose metabolism and extracellular glucose concentration, presumably due to similarities in membrane composition. Oxygen consumption by myocytes incubated in medium containing physiological levels of extracellular glucose (Atlantic cod 5 mmol l(-1), short-horned sculpin 0.5 mmol l(-1)) was similar in the two species and was not decreased by cytochalasin B, suggesting that these cells have the capability of oxidizing alternative on-board metabolic fuels. Cells produced lactate at low rates but glycogen levels did not change during the incubation period. In cells from both species, glucose utilization assessed by both simple chemical analysis of glucose disappearance from the medium and (3)H2O production was half the rate of lactate production and as such extracellular glucose was not available for oxidative metabolism

  2. NAD(P)H oxidase-dependent intracellular and extracellular O2·- production in coronary arterial myocytes from CD38 knockout mice

    PubMed Central

    Xu, Ming; Zhang, Yang; Xia, Min; Li, Xiao-Xue; Ritter, Joseph K; Zhang, Fan; Li, Pin-Lan

    2011-01-01

    Activation of NAD(P)H oxidase has been reported to produce superoxide (O2 ·-) extracellularly as an autocrine/paracrine regulator or intracellularly as a signaling messenger in a variety of mammalian cells. However, it remains unknown how the activity of NAD(P)H oxidase is regulated in arterial myocytes. Recently, CD38-associated ADP-ribosylcyclase has been reported to use NAD(P)H oxidase product, NAD+ or NADP+ to produce cyclic ADP-ribose (cADPR) or nicotinic acid adenine dinucleotide phosphate (NAADP), which mediates intracellular Ca2+ signaling. The present study was designed to test a hypothesis that CD38/cADPR pathway as a downstream event exerts feedback regulatory action on the NAD(P)H oxidase activity in production of extra- or intracellular O2 ·-in mouse coronary arterial myocytes (CAMs). By fluorescent microscopic imaging, we simultaneously monitored extra- and intracellular O2 ·-production in wild-type (CD38+/+) and CD38 knockout (CD38-/-) CAMs in response to oxotremorine (OXO), a muscarinic type 1 (M1) receptor agonist. It was found that CD38 deficiency prevented OXO-induced intracellular but not extracellular O2 ·-production in CAMs. Consistently, the OXO-induced intracellular O2 ·-production was markedly inhibited by CD38 shRNA or CD38 inhibitor nicotinamide in CD38+/+ CAMs. Further, Nox4 siRNA inhibited OXO-induced intracellular but not extracellular O2 ·- production, whereas Nox1 siRNA attenuated both intracellular and extracellular O2 ·-production in CD38+/+ CAMs. Direct delivery of exogenous cADPR into CAMs markedly elevated intracellular Ca2+ concentration and restored intracellular O2 ·-production in CD38-/- CAMs. Functionally, CD38 deficiency or Nox1 siRNA and Nox4 siRNA prevented OXO-induced contraction in isolated perfused coronary arteries in CD38 WT mice. These results provide direct evidence that CD38/cADPR pathway importantly controls Nox4-mediated intracellular O2 ·-production and that CD38-dependent intracellular O2 ·-production

  3. Relation of nutrient concentrations, nutrient loading, and algal production to changes in water levels in Kabetogama Lake, Voyageurs National Park, northern Minnesota, 2008-09

    USGS Publications Warehouse

    Christensen, Victoria G.; Maki, Ryan P.; Kiesling, Richard L.

    2011-01-01

    Nutrient enrichment has led to excessive algal growth in Kabetogama Lake, Voyageurs National Park, northern Minnesota. Water- and sediment-quality data were collected during 2008-09 to assess internal and external nutrient loading. Data collection was focused in Kabetogama Lake and its inflows, the area of greatest concern for eutrophication among the lakes of Voyageurs National Park. Nutrient and algal data were used to determine trophic status and were evaluated in relation to changes in Kabetogama Lake water levels following changes to dam operation starting in 2000. Analyses were used to estimate external nutrient loading at inflows and assess the potential contribution of internal phosphorus loading. Kabetogama Lake often was mixed vertically, except for a few occasionally stratified areas, including Lost Bay in the northeastern part of Kabetogama Lake. Stratification, combined with larger bottom-water nutrient concentrations, larger sediment phosphorus concentrations, and estimated phosphorus release rates from sediment cores indicate that Lost Bay may be one of several areas that may be contributing substantially to internal loading. Internal loading is a concern because nutrients may cause excessive algal growth including potentially toxic cyanobacteria. The cyanobacterial hepatotoxin, microcystin, was detected in 7 of 14 cyanobacterial bloom samples, with total concentrations exceeding 1.0 microgram per liter, the World Health Organization's guideline for finished drinking water for the congener, microcystin-LR. Comparisons of the results of this study to previous studies indicate that chlorophyll-a concentrations and trophic state indices have improved since 2000, when the rules governing dam operation changed. However, total-phosphorus concentrations have not changed significantly since 2000.

  4. ROS Production via P2Y1-PKC-NOX2 Is Triggered by Extracellular ATP after Electrical Stimulation of Skeletal Muscle Cells.

    PubMed

    Díaz-Vegas, Alexis; Campos, Cristian A; Contreras-Ferrat, Ariel; Casas, Mariana; Buvinic, Sonja; Jaimovich, Enrique; Espinosa, Alejandra

    2015-01-01

    During exercise, skeletal muscle produces reactive oxygen species (ROS) via NADPH oxidase (NOX2) while inducing cellular adaptations associated with contractile activity. The signals involved in this mechanism are still a matter of study. ATP is released from skeletal muscle during electrical stimulation and can autocrinely signal through purinergic receptors; we searched for an influence of this signal in ROS production. The aim of this work was to characterize ROS production induced by electrical stimulation and extracellular ATP. ROS production was measured using two alternative probes; chloromethyl-2,7- dichlorodihydrofluorescein diacetate or electroporation to express the hydrogen peroxide-sensitive protein Hyper. Electrical stimulation (ES) triggered a transient ROS increase in muscle fibers which was mimicked by extracellular ATP and was prevented by both carbenoxolone and suramin; antagonists of pannexin channel and purinergic receptors respectively. In addition, transient ROS increase was prevented by apyrase, an ecto-nucleotidase. MRS2365, a P2Y1 receptor agonist, induced a large signal while UTPyS (P2Y2 agonist) elicited a much smaller signal, similar to the one seen when using ATP plus MRS2179, an antagonist of P2Y1. Protein kinase C (PKC) inhibitors also blocked ES-induced ROS production. Our results indicate that physiological levels of electrical stimulation induce ROS production in skeletal muscle cells through release of extracellular ATP and activation of P2Y1 receptors. Use of selective NOX2 and PKC inhibitors suggests that ROS production induced by ES or extracellular ATP is mediated by NOX2 activated by PKC.

  5. ROS Production via P2Y1-PKC-NOX2 Is Triggered by Extracellular ATP after Electrical Stimulation of Skeletal Muscle Cells

    PubMed Central

    Díaz-Vegas, Alexis; Campos, Cristian A.; Contreras-Ferrat, Ariel; Casas, Mariana; Buvinic, Sonja; Jaimovich, Enrique; Espinosa, Alejandra

    2015-01-01

    During exercise, skeletal muscle produces reactive oxygen species (ROS) via NADPH oxidase (NOX2) while inducing cellular adaptations associated with contractile activity. The signals involved in this mechanism are still a matter of study. ATP is released from skeletal muscle during electrical stimulation and can autocrinely signal through purinergic receptors; we searched for an influence of this signal in ROS production. The aim of this work was to characterize ROS production induced by electrical stimulation and extracellular ATP. ROS production was measured using two alternative probes; chloromethyl-2,7- dichlorodihydrofluorescein diacetate or electroporation to express the hydrogen peroxide-sensitive protein Hyper. Electrical stimulation (ES) triggered a transient ROS increase in muscle fibers which was mimicked by extracellular ATP and was prevented by both carbenoxolone and suramin; antagonists of pannexin channel and purinergic receptors respectively. In addition, transient ROS increase was prevented by apyrase, an ecto-nucleotidase. MRS2365, a P2Y1 receptor agonist, induced a large signal while UTPyS (P2Y2 agonist) elicited a much smaller signal, similar to the one seen when using ATP plus MRS2179, an antagonist of P2Y1. Protein kinase C (PKC) inhibitors also blocked ES-induced ROS production. Our results indicate that physiological levels of electrical stimulation induce ROS production in skeletal muscle cells through release of extracellular ATP and activation of P2Y1 receptors. Use of selective NOX2 and PKC inhibitors suggests that ROS production induced by ES or extracellular ATP is mediated by NOX2 activated by PKC. PMID:26053483

  6. ROS Production via P2Y1-PKC-NOX2 Is Triggered by Extracellular ATP after Electrical Stimulation of Skeletal Muscle Cells.

    PubMed

    Díaz-Vegas, Alexis; Campos, Cristian A; Contreras-Ferrat, Ariel; Casas, Mariana; Buvinic, Sonja; Jaimovich, Enrique; Espinosa, Alejandra

    2015-01-01

    During exercise, skeletal muscle produces reactive oxygen species (ROS) via NADPH oxidase (NOX2) while inducing cellular adaptations associated with contractile activity. The signals involved in this mechanism are still a matter of study. ATP is released from skeletal muscle during electrical stimulation and can autocrinely signal through purinergic receptors; we searched for an influence of this signal in ROS production. The aim of this work was to characterize ROS production induced by electrical stimulation and extracellular ATP. ROS production was measured using two alternative probes; chloromethyl-2,7- dichlorodihydrofluorescein diacetate or electroporation to express the hydrogen peroxide-sensitive protein Hyper. Electrical stimulation (ES) triggered a transient ROS increase in muscle fibers which was mimicked by extracellular ATP and was prevented by both carbenoxolone and suramin; antagonists of pannexin channel and purinergic receptors respectively. In addition, transient ROS increase was prevented by apyrase, an ecto-nucleotidase. MRS2365, a P2Y1 receptor agonist, induced a large signal while UTPyS (P2Y2 agonist) elicited a much smaller signal, similar to the one seen when using ATP plus MRS2179, an antagonist of P2Y1. Protein kinase C (PKC) inhibitors also blocked ES-induced ROS production. Our results indicate that physiological levels of electrical stimulation induce ROS production in skeletal muscle cells through release of extracellular ATP and activation of P2Y1 receptors. Use of selective NOX2 and PKC inhibitors suggests that ROS production induced by ES or extracellular ATP is mediated by NOX2 activated by PKC. PMID:26053483

  7. Collection and conversion of algal lipid

    NASA Astrophysics Data System (ADS)

    Lin, Ching-Chieh

    Sustainable economic activities mandate a significant replacement of fossil energy by renewable forms. Algae-derived biofuels are increasingly seen as an alternative source of energy with potential to supplement the world's ever increasing demand. Our primary objective is, once the algae were cultivated, to eliminate or make more efficient energy-intensive processing steps of collection, drying, grinding, and solvent extraction prior to conversion. To overcome the processing barrier, we propose to streamline from cultivated algae to biodiesel via algal biomass collection by sand filtration, cell rupturing with ozone, and immediate transesterification. To collect the algal biomass, the specific Chlorococcum aquaticum suspension was acidified to pH 3.3 to promote agglomeration prior to sand filtration. The algae-loaded filter bed was drained of free water and added with methanol and ozonated for 2 min to rupture cell membrane to accelerate release of the cellular contents. The methanol solution now containing the dissolved lipid product was collected by draining, while the filter bed was regenerated by further ozonation when needed. The results showed 95% collection of the algal biomass from the suspension and a 16% yield of lipid from the algae, as well as restoration of filtration velocity of the sand bed via ozonation. The results further showed increased lipid yield upon cell rupturing and transesterified products composed entirely of fatty acid methyl ester (FAME) compounds, demonstrating that the rupture and transesterification processes could proceed consecutively in the same medium, requiring no separate steps of drying, extraction, and conversion. The FAME products from algae without exposure to ozone were mainly of 16 to 18 carbons containing up to 3 double bonds, while those from algae having been ozonated were smaller, highly saturated hydrocarbons. The new technique streamlines individual steps from cultivated algal lipid to transesterified products and

  8. [Effect of preozonation on disinfection by-products formation potential of algae cells and extracellular organic matter].

    PubMed

    Fang, Jing-yun; Ma, Jun; Wang, Li-ning; Zhang, Tao; Chen, Zhong-lin; Gao, Yue-hua

    2006-06-01

    Water containing Oscillatoria agardii was cultured under controlled conditions and harvested in the late log growth phase. The objective was to determine: the contribution of algae cells and algae extracellular organic matter (EOM) to the disinfection by-products formation potential (DBPFP), and the effects of preozonation including ozone dosage and preozonation time on DBPFP of algae cells and EOM and mechanism of these effects. The results show that the main trihalomethanes from both Oscillatoria cells and EOM are chloroform and bromodichloromethane, and that the main haloacetic acids are dichloroacetic acid and trichloroacetic acid. HAAFP from algae cells and EOM themselves or after preozonation followed by coagulation is more than THMFP, which shows that more attention should be paid to the control of HAA in the treatment of algae containing water. DBPFP of EOM is reduced by preozonation, and DBPFP clearly decreases with time. Compared with traditional coagulation, the dosage of 0.975 mg/L preozonation with reaction time of 10 minntes followed by coagulation can decrease DBPFP of EOM by 31% and decrease HAAFP by 52.6%, but increase THMFP by 12.5% under this experiment's condition. This result shows the major reason preozonation can control the DBPFP of EOM is that it can control HAAFP effectively. At the same time, the DBPFP of algae cells is significantly increased by preozonation, and this increase is almost a linear function of preozonation time. It can be concluded that in the real water treatment case most of algae cells should be removed intact before preozonation to control the DBPFP.

  9. Aberrant production of extracellular matrix proteins and dysfunction in kidney endothelial cells with a short duration of diabetes.

    PubMed

    Grutzmacher, Cathy; Park, SunYoung; Zhao, Yun; Morrison, Margaret E; Sheibani, Nader; Sorenson, Christine M

    2013-01-01

    Diabetic nephropathy is the most common cause of end-stage renal disease and is a major risk factor for cardiovascular disease. In the United States, microvascular complications during diabetic nephropathy contribute to high morbidity and mortality rates. However, the cell-autonomous impact of diabetes on kidney endothelial cell function requires further investigation. Male Akita/+ [autosomal dominant mutation in the insulin II gene (Ins2)] mice reproducibly develop diabetes by 4 wk of age. Here, we examined the impact a short duration of diabetes had on kidney endothelial cell function. Kidney endothelial cells were prepared from nondiabetic and diabetic mice (4 wk of diabetes) to delineate the early changes in endothelial cell function. Kidney endothelial cells from Akita/+ mice following 4 wk of diabetes demonstrated aberrant expression of extracellular matrix proteins including decreased osteopontin and increased fibronectin expression which correlated with increased α5-integrin expression. These changes were associated with the attenuation of migration and capillary morphogenesis. Kidney endothelial cells from Akita/+ mice had decreased VEGF levels but increased levels of endothelial nitric oxide synthase(eNOS) and NO, suggesting uncoupling of VEGF-mediated NO production. Knocking down eNOS expression in Akita/+ kidney endothelial cells increased VEGF expression, endothelial cell migration, and capillary morphogenesis. Furthermore, attenuation of sprouting angiogenesis of aortas from Akita/+ mice with 8 wk of diabetes was restored in the presence of the antioxidant N-acetylcysteine. These studies demonstrate that aberrant endothelial cell function with a short duration of diabetes may set the stage for vascular dysfunction and rarefaction at later stages of diabetes.

  10. Virulence of Aeromonas hydrophila to channel catfish Ictaluras punctatus fingerlings in the presence and absence of bacterial extracellular products.

    PubMed

    Pridgeon, Julia W; Klesius, Phillip H

    2011-07-12

    We investigated the virulence of three 2009 west Alabama isolates of Aeromonas hydrophila (AL09-71, AL09-72 and AL09-73) to channel catfish Ictalurus punctatus fingerlings (4.6 +/- 1.3 g) in the presence and absence of extracellular products (ECPs) from overnight bacterial culture using both bath immersion and intraperitoneal injection routes. At a concentration of 1.65 x 10(8) colony-forming units (CFU) ml(-1), AL09-73 without its ECPs killed 100% of the catfish fingerlings within 2 h by bath immersion. However, at a similar concentration, AL09-73 in the presence of its ECPs killed only 23 +/- 6% catfish fingerlings. The absence of ECPs in the bath immersion experiment also significantly (p < 0.05) increased the virulence of AL09-71, AL09-72, and AL98-C1B, a 1998 Alabama strain of A. hydrophila, suggesting that the virulence of the 4 A. hydrophila isolates was mainly due to bacterial cells, not to their overnight ECPs. Filter-sterilized ECPs failed to kill any catfish by bath immersion or injection. The virulence order of the 4 A. hydrophila isolates, by both bath immersion and intraperitoneal injection, was: AL09-73 > or = AL09-71 > AL09-72 > or = AL98-C1B. At 2 h post bath immersion, all 4 isolates of A. hydrophila were found in all tissues studied (skin, intestine, liver, spleen, kidney, gill and brain), with the highest bacteria count being in the gill and kidney.

  11. Relationship between Extracellular Low-Molecular-Weight Thiols and Mercury Species in Natural Lake Periphytic Biofilms.

    PubMed

    Leclerc, Maxime; Planas, Dolors; Amyot, Marc

    2015-07-01

    The uptake of mercury by microorganisms is a key step in the production of methylmercury, a biomagnifiable toxin. Mercury complexation by low-molecular-weight (LMW) thiols can affect its bioavailability and thus the production of methylmercury. Freshwater biofilms were sampled in the summer using artificial Teflon substrates submerged for over a year to allow natural community colonization in the littoral zone of a Boreal Shield lake. Inside biofilms, concentrations of different extracellular thiol species (thioglycolic acid, l-cysteine-l-glycine, cysteine, and glutathione) were up to 3 orders of magnitude greater than in the surrounding water column, potentially more readily controlling mercury speciation than in the water column. All biofilm thiols except thioglycolic acid were highly correlated to chlorophyll a, likely indicating an algal origin. Extracellular total mercury represented 3 ± 1% of all biofilm mercury and was preferentially found in the capsular fraction. Levels of LMW thiols of presumed algal origins were highly correlated with total mercury in the mobile colloidal fraction of biofilms. We propose that periphytic phototrophic microorganisms such as algae likely affect the bioavailability of mercury through the exudation of LMW thiols, and thus they may play a key role in the production of methylmercury in biofilms. PMID:26011687

  12. Relationship between Extracellular Low-Molecular-Weight Thiols and Mercury Species in Natural Lake Periphytic Biofilms.

    PubMed

    Leclerc, Maxime; Planas, Dolors; Amyot, Marc

    2015-07-01

    The uptake of mercury by microorganisms is a key step in the production of methylmercury, a biomagnifiable toxin. Mercury complexation by low-molecular-weight (LMW) thiols can affect its bioavailability and thus the production of methylmercury. Freshwater biofilms were sampled in the summer using artificial Teflon substrates submerged for over a year to allow natural community colonization in the littoral zone of a Boreal Shield lake. Inside biofilms, concentrations of different extracellular thiol species (thioglycolic acid, l-cysteine-l-glycine, cysteine, and glutathione) were up to 3 orders of magnitude greater than in the surrounding water column, potentially more readily controlling mercury speciation than in the water column. All biofilm thiols except thioglycolic acid were highly correlated to chlorophyll a, likely indicating an algal origin. Extracellular total mercury represented 3 ± 1% of all biofilm mercury and was preferentially found in the capsular fraction. Levels of LMW thiols of presumed algal origins were highly correlated with total mercury in the mobile colloidal fraction of biofilms. We propose that periphytic phototrophic microorganisms such as algae likely affect the bioavailability of mercury through the exudation of LMW thiols, and thus they may play a key role in the production of methylmercury in biofilms.

  13. System development for linked-fermentation production of solvents from algal biomass. [Dunaliella tertiolecta, D. primolecta, D. parva, D. bardawil, D. salina

    SciTech Connect

    Nakas, J.P.; Schaedele, M.; Parkinsan, C.M.; Coonley, C.E.; Tanenbaum, S.W.

    1983-11-01

    Five species of the genus Dunaliella (D. tertiolecta, D. primolecta, D. parva, D. bardawil, and D. salina) were examined for glycerol accumulation, growth rate, cell density, and protein and chlorophyll content. The suitability of each algal species for use as a fermentation substrate was judged according to glycerol accumulation and quantities of neutral solvents produced after sequential bacterial fermentations. When grown in 2 M NaCl, with 24 mM NaHCO3 or 3% CO2 at 28 degrees C and with 10,000 to 15,000 lx of incident light on two sides of a glass aquarium, four of the five species tested produced ca. 10 to 20 mg of glycerol per liter of culture. Clostridium pasteurianum was found to convert an algal biomass mixture supplemented with 4% glycerol to ca. 16 g of mixed solvents (n-butanol, 1,3-propanediol, and ethanol) per liter. Acetone was not detected. Additionally, it has been demonstrated that Dunaliella concentrates of up to 300-fold can be directly fermented to an identical pattern of mixed solvents. Overall solvent yields were reduced by more than 50% when fermentations were performed in the presence of 2% NaCl. These results are discussed in terms of practical application in tropical coastal zones.

  14. Algal toxins and reverse osmosis desalination operations: laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid.

    PubMed

    Seubert, Erica L; Trussell, Shane; Eagleton, John; Schnetzer, Astrid; Cetinić, Ivona; Lauri, Phil; Jones, Burton H; Caron, David A

    2012-12-01

    The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

  15. Algal Energy Conversion and Capture

    NASA Astrophysics Data System (ADS)

    Hazendonk, P.

    2015-12-01

    We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

  16. Algal functional annotation tool

    SciTech Connect

    Lopez, D.; Casero, D.; Cokus, S. J.; Merchant, S. S.; Pellegrini, M.

    2012-07-01

    The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG pathway maps and batch gene identifier conversion.

  17. Moderate extracellular acidification inhibits capsaicin-induced cell death through regulating calcium mobilization, NF-{kappa}B translocation and ROS production in synoviocytes

    SciTech Connect

    Hu, Fen; Yang, Shuang; Zhao, Dan; Zhu, Shuyan; Wang, Yuxiang; Li, Junying

    2012-07-20

    Highlights: Black-Right-Pointing-Pointer Moderate extracellular acidification regulates intracellular Ca{sup 2+} mobilization. Black-Right-Pointing-Pointer Moderate acidification activates NF-{kappa}B nuclear translocation in synoviocytes. Black-Right-Pointing-Pointer Moderate acidification depresses the ROS production induced by capsaicin. Black-Right-Pointing-Pointer Moderate acidification inhibits capsaicin-caused synoviocyte death. -- Abstract: We previously show the expression of transient receptor potential vanilloid 1 (TRPV1) in primary synoviocytes from collagen-induced arthritis (CIA) rats. Capsaicin and lowered extracellular pH from 7.4 to 5.5 induce cell death through TRPV1-mediated Ca{sup 2+} entry and reactive oxygen species (ROS) production. However, under the pathological condition in rheumatoid arthritis, the synovial fluid is acidified to a moderate level (about pH 6.8). In the present study, we examined the effects of pH 6.8 on the TRPV1-mediated cell death. Our finding is different or even opposite from what was observed at pH 5.5. We found that the moderate extracellular acidification (from pH 7.4 to 6.8) inhibited the capsaicin-induced Ca{sup 2+} entry through attenuating the activity of TRPV1. In the mean time, it triggered a phospholipse C (PLC)-related Ca{sup 2+} release from intracellular stores. The nuclear translocation of NF-{kappa}B was found at pH 6.8, and this also depends on PLC activation. Moreover, the capsaicin-evoked massive ROS production and cell death were depressed at pH 6.8, both of which are dependent on the activation of PLC and NF-{kappa}B. Taken together, these results suggested that the moderate extracellular acidification inhibited the capsaicin-induced synoviocyte death through regulating Ca{sup 2+} mobilization, activating NF-{kappa}B nuclear translocation and depressing ROS production.

  18. Improved algal harvesting using suspended air flotation.

    PubMed

    Wiley, Patrick E; Brenneman, Kristine J; Jacobson, Arne E

    2009-07-01

    Current methods to remove algae from a liquid medium are energy intensive and expensive. This study characterized algae contained within a wastewater oxidation pond and sought to identify a more efficient harvesting technique. Analysis of oxidation pond wastewater revealed that algae, consisting primarily of Chlorella and Scenedesmus, composed approximately 80% of the solids inventory during the study period. Results demonstrated that suspended air flotation (SAF) could harvest algae with a lower air:solids (A/S) ratio, lower energy requirements, and higher loading rates compared to dissolved air flotation (DAF) (P < 0.001). Identification of a more efficient algal harvesting system may benefit wastewater treatment plants by enabling cost effective means to reduce solids content of the final effluent. Furthermore, use of SAF to harvest commercially grown Chlorella and Scenedesmus may reduce manufacturing costs of algal-based products such as fuel, fertilizer, and fish food.

  19. Liquid transportation fuels from algal oils

    NASA Astrophysics Data System (ADS)

    Chen, Daichuan

    Liquid transportation fuels from renewable sources are becoming more prominent and important in modem society. Processing of hydrocarbon oils from algae has not been studied in detail in the past, so components which have been proposed for incorporation in algal oils via genetic engineering, such as cuparene, farnesene, phytol and squalene, have been subjected to processing via catalytic cracking in a pulse reactor at different temperatures. The cracking results showed that liquid products contained numerous high octane molecules which make it feasible for use in automobiles. Additionally, canola oil, chosen as an algal oil model compound, was studied as a feed for catalytic cracking in a fixed-bed reactor at atmospheric pressure over different types of zeolites. The results showed that MFI catalysts gave the highest yield of gasoline range products and lowest coke formation. Gallium loaded MFI zeolites increased the total aromatics yield for the canola oil cracking relative to the acid form of the zeolite. Finally, algal oils were cracked on several selected zeolites, and the results showed the same trend as canola oil cracking. MFI gave the highest gasoline yield (43.8 wt%) and lowest coke (4.7 wt%). The total aromatics yield from algae oil cracking is improved 7.8 wt% when MFI is loaded with gallium.

  20. Algal Biofuels; Algal Biofuels R&D at NREL (Brochure)

    SciTech Connect

    Not Available

    2010-09-01

    An overview of NREL's algal biofuels projects, including U.S. Department of Energy-funded work, projects with U.S. and international partners, and Laboratory Directed Research and Development projects.

  1. Improvement of Aspergillus oryzae NRRL 3484 by mutagenesis and optimization of culture conditions in solid-state fermentation for the hyper-production of extracellular cellulase.

    PubMed

    El-Ghonemy, Dina Helmy; Ali, Thanaa Hamed; El-Bondkly, Ahmed Mohamed; Moharam, Maysa El-Sayed; Talkhan, Fatma Nabeeh

    2014-11-01

    Spore suspensions of Aspergillus oryzae NRRL 3484 were subjected to mutagenesis using ultraviolet-irradiation followed by chemical treatments to improve the biosynthesis of cellulase. Ten mutant strains namely UEAC7, UEAR5, UNAC4, UNAC16, UNAR19, UNBC7, UNBR3, UNBR10, UNBR23 and UNBR25 were selected and their extracellular cellulase activities were assayed. Mutant UNAC4 gave the highest cellulase production [2,455 ± 28 U/g-dry substrate (ds) for filter paper-ase (FP-ase)] in a yield 4-fold exceeding that of the wild type strain (578 ± 5.0 U/g-ds for FP-ase). Rice straw (RS) was used as a sole carbon source for the enzyme production at a concentration of 10 % (w/v). Maximum cellulase production was achieved at initial medium pH 5.5, initial moisture content 77 % and an incubation temperature 28 °C on the fifth day of growth. NH4Cl proved to be the suitable added nitrogen source for maximum enzyme production followed by peptone. These results clearly indicate the cost-effectiveness of solid state fermentation technology in the economic production of extracellular cellulase. The hyper-production of cellulase by mutant strain UNAC4 has potential for industrial processes that convert lignocellulosic material (e.g. RS) into products of commercial value such as glucose and biofuels.

  2. Improvement of Aspergillus oryzae NRRL 3484 by mutagenesis and optimization of culture conditions in solid-state fermentation for the hyper-production of extracellular cellulase.

    PubMed

    El-Ghonemy, Dina Helmy; Ali, Thanaa Hamed; El-Bondkly, Ahmed Mohamed; Moharam, Maysa El-Sayed; Talkhan, Fatma Nabeeh

    2014-11-01

    Spore suspensions of Aspergillus oryzae NRRL 3484 were subjected to mutagenesis using ultraviolet-irradiation followed by chemical treatments to improve the biosynthesis of cellulase. Ten mutant strains namely UEAC7, UEAR5, UNAC4, UNAC16, UNAR19, UNBC7, UNBR3, UNBR10, UNBR23 and UNBR25 were selected and their extracellular cellulase activities were assayed. Mutant UNAC4 gave the highest cellulase production [2,455 ± 28 U/g-dry substrate (ds) for filter paper-ase (FP-ase)] in a yield 4-fold exceeding that of the wild type strain (578 ± 5.0 U/g-ds for FP-ase). Rice straw (RS) was used as a sole carbon source for the enzyme production at a concentration of 10 % (w/v). Maximum cellulase production was achieved at initial medium pH 5.5, initial moisture content 77 % and an incubation temperature 28 °C on the fifth day of growth. NH4Cl proved to be the suitable added nitrogen source for maximum enzyme production followed by peptone. These results clearly indicate the cost-effectiveness of solid state fermentation technology in the economic production of extracellular cellulase. The hyper-production of cellulase by mutant strain UNAC4 has potential for industrial processes that convert lignocellulosic material (e.g. RS) into products of commercial value such as glucose and biofuels. PMID:25119245

  3. Extracellular polysaccharide production by a strain of Pleurotus djamor isolated in the south of Brazil and antitumor activity on Sarcoma 180

    PubMed Central

    Borges, Gisele Martini; De Barba, Fabiana Figueredo Molin; Schiebelbein, Ana Paula; Pereira, Bruna Parmezzani; Chaves, Mariane Bonatti; Silveira, Marcia Luciane Lange; Pinho, Mauro Souza Leite; Furlan, Sandra Aparecida; Wisbeck, Elisabeth

    2013-01-01

    Polysaccharides with medicinal properties can be obtained from fruiting bodies, mycelium and culture broth of several fungus species. This work was carried out in batch culture using a stirred tank reactor with two different initial glucose concentrations (40–50 g/L) and pH values (3.0–4.0) to enhance extracellular polysaccharides production by Pleurotus djamor UNIVILLE 001 and evaluate antitumor effect of intraperitonial administration of Pleurotus djamor extract on sarcoma 180 animal model. According to factorial design, the low pH value (pH 3.0) led to a gain of 1.6 g/L on the extracellular polysaccharide concentration, while glucose concentration in the tested range had no significant effect on the concentration of polysaccharide. With 40 g/L initial glucose concentration and pH 3.0, it was observed that yield factor of extracellular polysaccharide on substrate (YP/S = 0.072) and maximum extracellular polysaccharide productivity (QPmax = 11.26 mg/L.h) were about 188% and 321% respectively higher than those obtained in the experiment performed at pH 4.0. Under these conditions, the highest values of the yield factor of biomass on substrate (YX/S = 0.24) and maximal biomass productivity (QXmax = 32.2 mg/L.h) were also reached. In tumor response study, mean tumor volume on the 21th day was 35.3 cm3 in untreated group and 1.6 cm3 in treated group (p = 0.05) with a tumor inhibition rate of 94%. These impressive results suggests an inhibitory effect of P.djamor extract on cancer cells. PMID:24688493

  4. The role of Aspergillus flavus veA in the production of extracellular proteins during growth on starch substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aflatoxin-producer and opportunistic plant pathogenic, filamentous fungus Aspergillus flavus is responsible for the contamination of corn and other important agricultural commodities. In order to obtain nutrients from the host A. flavus produces a variety of extracellular hydrolytic enzymes. Int...

  5. Production of extracellular proteolytic activity by Histoplasma capsulatum grown in Histoplasma-macrophage medium is limited to restriction fragment length polymorphism class 1 isolates.

    PubMed

    Zarnowski, Robert; Connolly, Patricia A; Wheat, L Joseph; Woods, Jon P

    2007-09-01

    Extracellular proteolytic activity was studied for 28 strains of Histoplasma capsulatum var. capsulatum and 2 strains of H. capsulatum var. duboisii. Secreted protease activity assessed by skim milk agarose clearance was limited solely to H. capsulatum var. capsulatum restriction fragment length polymorphism (RFLP) class 1 strains. There was a difference in proteolytic activity levels among class 1 strains. Extracellular proteolytic activity was further determined during growth of those strains in liquid medium using azodye-impregnated protein substrates. In general, the highest activities were measured when azocollagen was used, whereas azocasein and azoalbumin were cleaved less efficiently. The activity was inhibited by phenylmethylsulfonyl fluoride, 4-(2-aminoethyl) benzenesulfonyl fluoride, antipain, and chymostatin, indicating, thereby, the presence of chymotrypsin-like serine proteases. Chromatographic analyses as well as variable substrate use at different culture times revealed production of at least 2 different enzyme pools of the same serine-like protease family. Our results demonstrate a distinctive ability of RFLP class 1 isolates to produce and secrete serine proteinase-type activity. This peculiarity may be relevant to the biology and pathogenesis of this particular clade of H. capsulatum isolates. Overall, the feature of extracellular proteolytic activity production enables a convenient and unequivocal identification of RFLP class 1 isolates and, thereby, can be used in H. capsulatum strain differentiation and typing. PMID:17509799

  6. The algal lift: Buoyancy-mediated sediment transport

    NASA Astrophysics Data System (ADS)

    Mendoza-Lera, Clara; Federlein, Laura L.; Knie, Matthias; Mutz, Michael

    2016-01-01

    The role of benthic algae as biostabilizers of sediments is well-known, however, their potential to lift and transport sediments remains unclear. Under low-flow conditions, matured algal mats may detach from the bed and may lift up sediment, thereby causing disturbance to the uppermost streambed sediment. We tested the potential of algal mats to lift sediments in 12 indoor flumes filled with sand (0.2 - 0.8 mm), gravel (2 - 8 mm) or a sand-gravel mixture (25/75% mass). After four weeks, the algal mats covered about 50% of the flumes area. Due to the accumulation of oxygen gas bubbles in the mats, that developed from high primary production at 4.5 weeks, about half of the algal mats detached from the bed carrying entangled sediments. Both the area covered by algal mats and detached area were similar among sediment types, but the amount of sediment transported tended to be higher for sand and sand-gravel mixture compared to gravel. Our results reveal that biologically mediated sediment transport mainly depends on the development of a dense filamentous algal matrix, that traps gas bubbles, increasing the mats buoyancy. This novel mechanism of sediment transport will occur in shallow ecosystems during low-flow periods, with the highest impact for sandy sediments.

  7. Extracellular ATP

    PubMed Central

    Chivasa, Stephen; Tomé, Daniel FA; Murphy, Alex M; Hamilton, John M; Lindsey, Keith; Carr, John P

    2009-01-01

    Living organisms acquire or synthesize high energy molecules, which they frugally conserve and use to meet their cellular metabolic demands. Therefore, it is surprising that ATP, the most accessible and commonly utilized chemical energy carrier, is actively secreted to the extracellular matrix of cells. It is now becoming clear that in plants this extracellular ATP (eATP) is not wasted, but harnessed at the cell surface to signal across the plasma membrane of the secreting cell and neighboring cells to cxontrol gene expression and influence plant development. Identification of the gene/protein networks regulated by eATP-mediated signaling should provide insight into the physiological roles of eATP in plants. By disrupting eATP-mediated signaling, we have identified pathogen defense genes as part of the eATP-regulated gene circuitry, leading us to the discovery that eATP is a negative regulator of pathogen defense in plants.1 Previously, we reported that eATP is a key signal molecule that modulates programmed cell death in plants.2 A complex picture is now emerging, in which eATP-mediated signaling cross-talks with signaling mediated by the major plant defense hormone, salicylic acid, in the regulation of pathogen defense and cell death. PMID:20009563

  8. Sterol phylogenesis and algal evolution

    SciTech Connect

    Nes, W.D.; Norton, R.A.; Crumley, F.G. ); Madigan, S.J.; Katz, E.R. )

    1990-10-01

    The stereochemistry of several sterol precursors and end products synthesized by two fungal-like microorganisms Prototheca wickerhamii (I) and Dictyostelium discoideum (II) have been determined by chromatographic (TLC, GLC, and HPLC) and spectral (UV, MS, and {sup 1}H NMR) methods. From I and II the following sterols were isolated from the cells: cycloartenol, cyclolaudenol, 24(28)-methylenecy-cloartanol, ergosterol, protothecasterol, 4{alpha}-methylergostanol, 4{alpha}-methylclionastanol, clionastanol, 24{beta}-ethylcholesta-8,22-enol, and dictyosterol. In addition, the mechanism of C-24 methylation was investigated in both organisms by feeding to I (2-{sup 3}H)lanosterol, (2-{sup 3}H)cycloartenol, (24{sup 3}H)lanosterol, and (methyl-{sup 2}H{sub 3})methionine and by feeding to II (methyl-{sup 2}H{sub 3})methionine. The results demonstrate that the 24{beta} configuration is formed by different alkylation routes in I and II. The authors conclude that Prototheca is an apoplastic Chlorella (i.e., an alga) and that Dictyostelium as well as the other soil amoebae that synthesize cycloartenol evolved from algal rather than fungal ancestors.

  9. Interactions of microbial biofilms with toxic trace metals; 1: Observation and modeling of cell growth, attachment, and production of extracellular polymer

    SciTech Connect

    Hsieh, K.M.; Murgel, G.A.; Lion, L.W.; Shuler, M.L. )

    1994-06-20

    Adsorbent surfaces in natural and engineered systems are frequently modified by bacterial attachment, growth of a biofilm, and bacterial production of extracellular polymer. Attached cells or sorbed polymers may alter the metal-binding characteristics of the supporting substratum and influence metal partitioning. The interdependent behavior of toxic trace metal partitioning and biofilm development requires description of the interaction between cell growth with its accompanying polymer production and metal speciation. In this article, the first of a two part series, a mechanistic model is developed to describe the growth of a film-forming bacterium which adheres to a substratum through the production of extracellular biopolymers. Each bacterial cell was modeled as a two-component structure consisting of active cell mass and biopolymer. The biopolymer component was further divided into cell-associated and dissolved categories to distinguish biopolymer which remained naturally bound to cell surfaces from that which did not. Use of this structured model permitted independent description of the dynamics of cell growth, and polymer production, both of which may influence trace metal behavior. Employing parameters obtained from independent experiments as well as published values, the model satisfactorily predicts experimental observations of bacterial growth, attachment and detachment, biopolymer production, and adsorption of polymer onto solid (glass) surfaces. The model simulated transient and steady-state biofilm systems equally well.

  10. Antimicrobial activity of neutralized extracellular culture filtrates of lactic acid bacteria isolated from a cultured Indian milk product ('dahi').

    PubMed

    Varadaraj, M C; Devi, N; Keshava, N; Manjrekar, S P

    1993-12-01

    Neutralized extracellular culture filtrate obtained from isolates of Lactobacillus acidophilus, Lactobacillus delbruecki ssp. bulgaricus, Lactobacillus salivarius and Lactococcus lactis ssp. lactis from 'dahi' showed weak to moderate inhibition of Staphylococcus aureus, Bacillus cereus, Escherichia coli, Bacillus brevis, Bacillus circulans, Bacillus coagulans, Bacillus laterosporus, Bacillus subtilis and Pseudomonas aeruginosa when tested by the diffusion agar well assay method. The effective minimum quantity of lactic culture filtrates required to obtain complete inhibition of an inoculum of 10(3) cfu/ml of the bacteria tested was between 20 and 26% (vol/vol), as determined by the agar incorporation method. Neutralized extracellular culture filtrate of these lactic cultures added at a level of 10% in sterile, 10% reconstituted non-fat dry milk was able to either suppress or retard growth of selected bacterial cultures when incubated at 37 degrees C for 24 h. This study indicated the antimicrobial activity of dahi and the potential of using neutralized extracellular culture filtrate of lactic acid bacteria in the biopreservation of foods.

  11. HSP70 increases extracellular matrix production by human vascular smooth muscle through TGF-β1 up-regulation.

    PubMed

    González-Ramos, Marta; Calleros, Laura; López-Ongil, Susana; Raoch, Viviana; Griera, Mercedes; Rodríguez-Puyol, Manuel; de Frutos, Sergio; Rodríguez-Puyol, Diego

    2013-02-01

    The circulating levels of heat shock proteins (HSP) are increased in cardiovascular diseases; however, the implication of this for the fibrotic process typical of such diseases remains unclear. HSP70 can interact with the vascular smooth muscle cells (SMC), the major producer of extracellular matrix (ECM) proteins, through the Toll-like receptors 4 (TLR4). The transforming growth factor type-β1 (TGF-β1) is a well known vascular pro-fibrotic cytokine that is regulated in part by AP-1-dependent transcriptional mechanisms. We hypothesized that extracellular HSP70 could interact with SMCs, inducing TGF-β1 synthesis and subsequent changes in the vascular ECM. We demonstrate that extracellular HSP70 binds to human aorta SMC TLR4, which up-regulates the AP-1-dependent transcriptional activity of the TGF-β1 promoter. This is achieved through the mitogen activated protein kinases JNK and ERK, as demonstrated by the use of specific blockers and the knockdown of TLR4 with specific small interfering RNAs. The TGF-β1 upregulation increase the expression of the ECM proteins type I collagen and fibronectin. This novel observation may elucidate the mechanisms by which HSP70 contributes in the inflammation and fibrosis present in atherosclerosis and other fibrosis-related diseases.

  12. HSP70 increases extracellular matrix production by human vascular smooth muscle through TGF-β1 up-regulation.

    PubMed

    González-Ramos, Marta; Calleros, Laura; López-Ongil, Susana; Raoch, Viviana; Griera, Mercedes; Rodríguez-Puyol, Manuel; de Frutos, Sergio; Rodríguez-Puyol, Diego

    2013-02-01

    The circulating levels of heat shock proteins (HSP) are increased in cardiovascular diseases; however, the implication of this for the fibrotic process typical of such diseases remains unclear. HSP70 can interact with the vascular smooth muscle cells (SMC), the major producer of extracellular matrix (ECM) proteins, through the Toll-like receptors 4 (TLR4). The transforming growth factor type-β1 (TGF-β1) is a well known vascular pro-fibrotic cytokine that is regulated in part by AP-1-dependent transcriptional mechanisms. We hypothesized that extracellular HSP70 could interact with SMCs, inducing TGF-β1 synthesis and subsequent changes in the vascular ECM. We demonstrate that extracellular HSP70 binds to human aorta SMC TLR4, which up-regulates the AP-1-dependent transcriptional activity of the TGF-β1 promoter. This is achieved through the mitogen activated protein kinases JNK and ERK, as demonstrated by the use of specific blockers and the knockdown of TLR4 with specific small interfering RNAs. The TGF-β1 upregulation increase the expression of the ECM proteins type I collagen and fibronectin. This novel observation may elucidate the mechanisms by which HSP70 contributes in the inflammation and fibrosis present in atherosclerosis and other fibrosis-related diseases. PMID:23084979

  13. Quorum sensing in marine snow and its possible influence on production of extracellular hydrolytic enzymes in marine snow bacterium Pantoea ananatis B9.

    PubMed

    Jatt, Abdul Nabi; Tang, Kaihao; Liu, Jiwen; Zhang, Zenghu; Zhang, Xiao-Hua

    2015-02-01

    Marine snow is a continuous shower of organic and inorganic detritus, and plays a crucial role in transporting materials from the sea surface to the deep ocean. The aims of the current study were to identify N-acyl homoserine lactone (AHL)-based quorum sensing (QS) signaling molecules directly from marine snow particles and to investigate the possible regulatory link between QS signals and extracellular hydrolytic enzymes produced by marine snow bacteria. The marine snow samples were collected from the surface water of China marginal seas. Two AHLs, i.e. 3OC6-HSL and C8-HSL, were identified directly from marine snow particles, while six different AHL signals, i.e. C4-HSL, 3OC6-HSL, C6-HSL, C10-HSL, C12-HSL and C14-HSL were produced by Pantoea ananatis B9 inhabiting natural marine snow particles. Of the extracellular hydrolytic enzymes produced by P. ananatis B9, alkaline phosphatase activity was highly enhanced in growth medium supplemented with exogenous AHL (C10-HSL), while quorum quenching enzyme (AiiA) drastically reduced the enzyme activity. To our knowledge, this is the first report revealing six different AHL signals produced by P. ananatis B9 and AHL-based QS system enhanced the extracellular hydrolytic enzyme in P. ananatis B9. Furthermore, this study first time revealing 3OC6-HSL production by Paracoccus carotinifaciens affiliated with Alphaproteobacteria. PMID:25764555

  14. Involvement of a new enzyme, glyoxal oxidase, in extracellular H/sub 2/O/sub 2/ production by Phanerochaete chrysosporium

    SciTech Connect

    Kersten, P.J.; Kirk, K.

    1987-05-01

    The importance of extracellular H/sub 2/O/sub 2/ in lignin degradation has become increasingly apparent with the recent discovery of H/sub 2/O/sub 2/-requiring ligninases produced by white-rot fungi. Here the authors describe a new H/sub 2/O/sub 2/-producing activity of Phanerochaete chrysosporium that involves extracellular oxidases able to use simple aldehyde, ..cap alpha..-hydroxycarbonyl, or..cap alpha..-dicarbonyl compounds as substrates. The activity is expressed during secondary metabolism, when the ligninases are also expressed. Analytical isoelectric focusing of the extracellular proteins, followed by activity staining, indicated that minor proteins with broad substrate specificities are responsible for the oxidase activity. Two of the oxidase substrates, glyoxal and methylglyoxal, were also identified, as their quinoxaline derivatives, in the culture fluid as secondary metabolites. The significance of these findings is discussed with respect to lignin degradation and other proposed systems for H/sub 2/O/sub 2/ production in P. chrysosporium.

  15. Quorum sensing in marine snow and its possible influence on production of extracellular hydrolytic enzymes in marine snow bacterium Pantoea ananatis B9.

    PubMed

    Jatt, Abdul Nabi; Tang, Kaihao; Liu, Jiwen; Zhang, Zenghu; Zhang, Xiao-Hua

    2015-02-01

    Marine snow is a continuous shower of organic and inorganic detritus, and plays a crucial role in transporting materials from the sea surface to the deep ocean. The aims of the current study were to identify N-acyl homoserine lactone (AHL)-based quorum sensing (QS) signaling molecules directly from marine snow particles and to investigate the possible regulatory link between QS signals and extracellular hydrolytic enzymes produced by marine snow bacteria. The marine snow samples were collected from the surface water of China marginal seas. Two AHLs, i.e. 3OC6-HSL and C8-HSL, were identified directly from marine snow particles, while six different AHL signals, i.e. C4-HSL, 3OC6-HSL, C6-HSL, C10-HSL, C12-HSL and C14-HSL were produced by Pantoea ananatis B9 inhabiting natural marine snow particles. Of the extracellular hydrolytic enzymes produced by P. ananatis B9, alkaline phosphatase activity was highly enhanced in growth medium supplemented with exogenous AHL (C10-HSL), while quorum quenching enzyme (AiiA) drastically reduced the enzyme activity. To our knowledge, this is the first report revealing six different AHL signals produced by P. ananatis B9 and AHL-based QS system enhanced the extracellular hydrolytic enzyme in P. ananatis B9. Furthermore, this study first time revealing 3OC6-HSL production by Paracoccus carotinifaciens affiliated with Alphaproteobacteria.

  16. Extracellular Production of a Novel Endo-β-Agarase AgaA from Pseudomonas vesicularis MA103 that Cleaves Agarose into Neoagarotetraose and Neoagarohexaose

    PubMed Central

    Hsu, Pang-Hung; Wei, Chien-Han; Lu, Wen-Jung; Shen, Fen; Pan, Chorng-Liang; Lin, Hong-Ting Victor

    2015-01-01

    The gene agaA, of the isolated marine bacterium Pseudomonas vesicularis MA103, comprised 2958-bp nucleotides encoding a putative agarase AgaA of 985 amino acids, which was predicted to contain a signal peptide of 29 amino acids in the N-terminus, a catalytic domain of glycoside hydrolase 16 (GH16) family, a bacterial immunoglobulin group 2 (Big 2), and three carbohydrate binding modules 6 (CBM 6). The gene agaA was cloned and overexpressed in Escherichia coli, and the optimum temperatures for AgaA overexpression were 16, 20 and 24 °C. The agaA was cloned without its signal peptide for cytosolic production overexpression, whereas it was cloned with the heterologous signal peptide PelB and its endogenous signal peptide for periplasmic and extracellular productions, respectively. Extracellular and periplasmic rAgaA showed greater activity than that of cytosolic rAgaA, indicating that membrane translocation of AgaA may encourage proper protein folding. Time-course hydrolysis of agarose by rAgaA was accomplished and the products were analyzed using thin layer chromatography and matrix-assisted laser desorption inoization-time of flight mass spectrometry, indicating that AgaA from P. vesicularis was an endo-type β-1,4 agarase that cleaved agarose into neoagarotetraose and neoagarohexaose as the final products. PMID:25768342

  17. Detection of surface algal blooms using the newly developed algorithm surface algal bloom index (SABI)

    NASA Astrophysics Data System (ADS)

    Alawadi, Fahad

    2010-10-01

    Quantifying ocean colour properties has evolved over the past two decades from being able to merely detect their biological activity to the ability to estimate chlorophyll concentration using optical satellite sensors like MODIS and MERIS. The production of chlorophyll spatial distribution maps is a good indicator of plankton biomass (primary production) and is useful for the tracing of oceanographic currents, jets and blooms, including harmful algal blooms (HABs). Depending on the type of HABs involved and the environmental conditions, if their concentration rises above a critical threshold, it can impact the flora and fauna of the aquatic habitat through the introduction of the so called "red tide" phenomenon. The estimation of chlorophyll concentration is derived from quantifying the spectral relationship between the blue and the green bands reflected from the water column. This spectral relationship is employed in the standard ocean colour chlorophyll-a (Chlor-a) product, but is incapable of detecting certain macro-algal species that float near to or at the water surface in the form of dense filaments or mats. The ability to accurately identify algal formations that sometimes appear as oil spill look-alikes in satellite imagery, contributes towards the reduction of false-positive incidents arising from oil spill monitoring operations. Such algal formations that occur in relatively high concentrations may experience, as in land vegetation, what is known as the "red-edge" effect. This phenomena occurs at the highest reflectance slope between the maximum absorption in the red due to the surrounding ocean water and the maximum reflectance in the infra-red due to the photosynthetic pigments present in the surface algae. A new algorithm termed the surface algal bloom index (SABI), has been proposed to delineate the spatial distributions of floating micro-algal species like for example cyanobacteria or exposed inter-tidal vegetation like seagrass. This algorithm was

  18. Carbon and light limitation in mass algal culture

    SciTech Connect

    Brune, D.E.

    1980-01-01

    The carbon limited kinetic responses of various fast growing algal species have been summarized. These results suggest that the growth responses of many algae used in mass culture may best be represented as a Monod fit of the specific growth rate (..mu..) to the free carbon dioxide concentration (CO/sub 2//sub f/). The environmental modifiers of primary importance appear to be light levels, temperature and the ionic strength of the growth media. The various mathematical models describing the algal biological response to limitng CO/sub 2//sub f/ concentration, the carbonate equilibrium chemistry and the physical configration of a flow-through microbial culture are combined to yield equations which predict the pH, total carbon concentration (C/sub T/) and algal cell concentration of a continuous alga culture, given a ..mu../sub max/ and K/sub SCO2/ for the alga of interest. This model is further used to illustrate the under-utilization of inorganic carbon in mass algal cultures in which the pH is uncontrolled. One method of pH control in such cultures involves the utilization of CO/sub 2/ supply from bacterial degradation of waste organics in the influent culture medium. In such a situation both the culture pH and algal cell production will often be governed by either carbon or light limitation depending primarily on the influent BOD loading, detention time and culture depth. In spite of the obvious over-simplification of considering only light and carbon limits in describing the behavior of mass algal culture, comparisons to actual field data suggest that these two parameters will be of paramount importance in controlling net algal cell production rates.

  19. Sterol phylogenesis and algal evolution.

    PubMed Central

    Nes, W D; Norton, R A; Crumley, F G; Madigan, S J; Katz, E R

    1990-01-01

    The stereochemistry of several sterol precursors and end products synthesized by two fungal-like micro-organisms Prototheca wickerhamii (I) and Dictyostelium discoideum (II) have been determined by chromatographic (TLC, GLC, and HPLC) and spectral (UV, MS, and 1H NMR) methods. From I and II the following sterols were isolated from the cells: cycloartenol, cyclolaudenol, 24(28)-methylenecycloartanol, ergosterol, protothecasterol, 4alpha-methylergostanol, 4alpha-methylclionastanol, clionastanol, 24beta-ethylcholesta-8,22-enol, and dictyosterol. In addition, the mechanism of C-24 methylation was investigated in both organisms by feeding to I [2-3H]lanosterol, [2-3H]cycloartenol, [24-3H]lanosterol, and [methyl-2H3]methionine and by feeding to II [methyl-2H3]methionine. The results demonstrate that the 24beta configuration is formed by different alkylation routes in I and II. The Delta25(27) route operates in I while the Delta24(28) route operates in II. Based on what is known in the literature regarding sterol distribution and phylogenesis together with our findings that the stereochemical outcome of squalene oxide cyclization leads to the production of cycloartenol rather than lanosterol (characteristic of the fungal genealogy) and the chirality of the C-24 alkyl group is similar in the two nonphotosynthetic microbes (beta oriented), we conclude that Prototheca is an apoplastic Chlorella (i.e., an alga) and that Dictyostelium as well as the other soil amoebae that synthesize cycloartenol evolved from algal rather than fungal ancestors. PMID:11607106

  20. Luminescent Solar Concentrators in the Algal Industry

    NASA Astrophysics Data System (ADS)

    Hellier, Katie; Corrado, Carley; Carter, Sue; Detweiler, Angela; Bebout, Leslie

    2013-03-01

    Today's industry for renewable energy sources and highly efficient energy management systems is rapidly increasing. Development of increased efficiency Luminescent Solar Concentrators (LSCs) has brought about new applications for commercial interests, including greenhouses for agricultural crops. This project is taking first steps to explore the potential of LSCs to enhance production and reduce costs for algae and cyanobacteria used in biofuels and nutraceuticals. This pilot phase uses LSC filtered light for algal growth trials in greenhouses and laboratory experiments, creating specific wavelength combinations to determine effects of discrete solar light regimes on algal growth and the reduction of heating and water loss in the system. Enhancing the optimal spectra for specific algae will not only increase production, but has the potential to lessen contamination of large scale production due to competition from other algae and bacteria. Providing LSC filtered light will reduce evaporation and heating in regions with limited water supply, while the increased energy output from photovoltaic cells will reduce costs of heating and mixing cultures, thus creating a more efficient and cost effective production system.

  1. Effect of C/N ratio and media optimization through response surface methodology on simultaneous productions of intra- and extracellular inulinase and invertase from Aspergillus niger ATCC 20611.

    PubMed

    Dinarvand, Mojdeh; Rezaee, Malahat; Masomian, Malihe; Jazayeri, Seyed Davoud; Zareian, Mohsen; Abbasi, Sahar; Ariff, Arbakariya B

    2013-01-01

    The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes from Aspergillus niger ATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO₃, Zn⁺², and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R²) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO₃, 1.5 mM (v/v) Zn⁺², and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry.

  2. Effect of C/N Ratio and Media Optimization through Response Surface Methodology on Simultaneous Productions of Intra- and Extracellular Inulinase and Invertase from Aspergillus niger ATCC 20611

    PubMed Central

    Dinarvand, Mojdeh; Rezaee, Malahat; Masomian, Malihe; Jazayeri, Seyed Davoud; Zareian, Mohsen; Abbasi, Sahar; Ariff, Arbakariya B.

    2013-01-01

    The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes from Aspergillus niger ATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO3, Zn+2, and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R2) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO3, 1.5 mM (v/v) Zn+2, and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry. PMID:24151605

  3. High level extracellular production of a recombinant alkaline catalase in E. coli BL21 under ethanol stress and its application in hydrogen peroxide removal after cotton fabrics bleaching.

    PubMed

    Yu, Zhenxiao; Zheng, Hongchen; Zhao, Xingya; Li, Shufang; Xu, Jianyong; Song, Hui

    2016-08-01

    The effects of induction parameters, osmolytes and ethanol stress on the productivity of the recombinant alkaline catalase (KatA) in Escherichia coli BL21 (pET26b-KatA) were investigated. The yield of soluble KatA was significantly enhanced by 2% ethanol stress. And a certain amount of Triton X-100 supplementation could markedly improved extracellular ratio of KatA. A total soluble catalase activity of 78,762U/mL with the extracellular ratio of 92.5% was achieved by fed-batch fermentation in a 10L fermentor, which was the highest yield so far. The purified KatA showed high stability at 50°C and pH 6-10. Application of KatA for elimination of H2O2 after cotton fabrics bleaching led to less consumption of water, steam and electric power by 25%, 12% and 16.7% respectively without productivity and quality losing of cotton fabrics. Thus, the recombinant KatA is a promising candidate for industrial production and applications. PMID:27151682

  4. Effect of C/N ratio and media optimization through response surface methodology on simultaneous productions of intra- and extracellular inulinase and invertase from Aspergillus niger ATCC 20611.

    PubMed

    Dinarvand, Mojdeh; Rezaee, Malahat; Masomian, Malihe; Jazayeri, Seyed Davoud; Zareian, Mohsen; Abbasi, Sahar; Ariff, Arbakariya B

    2013-01-01

    The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes from Aspergillus niger ATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO₃, Zn⁺², and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R²) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO₃, 1.5 mM (v/v) Zn⁺², and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry. PMID:24151605

  5. Algal culture studies related to a Closed Ecological Life Support System (CELSS)

    NASA Technical Reports Server (NTRS)

    Radmer, R. O.; Ollinger, O.; Venables, A.; Fernandez, E.

    1982-01-01

    Studies with algal cultures which relate to closed ecological life support systems (CELSS) are discussed. A description of a constant cell density apparatus for continuous culture of algae is included. Excretion of algal by-products, and nitrogen utilization and excretion are discussed.

  6. Releasing Stored Solar Energy within Pond Scum: Biodiesel from Algal Lipids

    ERIC Educational Resources Information Center

    Blatti, Jillian L.; Burkart, Michael D.

    2012-01-01

    Microalgae have emerged as an attractive feedstock for the mass production of renewable transportation fuels due to their fast growth rate, flexible habitat preferences, and substantial oil yields. As an educational tool, a laboratory was developed that mimics emerging algal biofuel technology, including the extraction of algal lipids and…

  7. Retinoic acid receptor-α signalling antagonizes both intracellular and extracellular amyloid-β production and prevents neuronal cell death caused by amyloid-β.

    PubMed

    Jarvis, C I; Goncalves, M B; Clarke, E; Dogruel, M; Kalindjian, S B; Thomas, S A; Maden, M; Corcoran, J P T

    2010-10-01

    Alzheimer's disease (AD) is characterized by amyloid-β (Aβ) deposition in the brain, neuronal cell loss and cognitive decline. We show here that retinoic acid receptor (RAR)α signalling in vitro can prevent both intracellular and extracellular Aβ accumulation. RARα signalling increases the expression of a disintegrin and metalloprotease 10, an α-secretase that processes the amyloid precursor protein into the non-amyloidic pathway, thus reducing Aβ production. We also show that RARα agonists are neuroprotective, as they prevent Aβ-induced neuronal cell death in cortical cultures. If RARα agonists are given to the Tg2576 mouse, the normal Aβ production in their brains is suppressed. In contrast, neither RARβ nor γ-agonists affect Aβ production or Aβ-mediated neuronal cell death. Therefore, RARα agonists have therapeutic potential for the treatment of AD.

  8. Algal taxonomy forum: Algal Taxonomist, Let Serendipity Reign!

    PubMed

    Druehl, Louis

    2013-04-01

    The publication of a mini-review by Olivier De Clerck et al. in this issue of the Journal of Phycology presented an opportunity to open a dialogue on challenges faced by contemporary algal taxonomists. The Editorial Office solicited the following two additional contributions in response to De Clerck et al.'s paper; the responses were edited solely for clarity, space and format.

  9. Potential of carbon nanotubes in algal biotechnology.

    PubMed

    Lambreva, Maya Dimova; Lavecchia, Teresa; Tyystjärvi, Esa; Antal, Taras Kornelievich; Orlanducci, Silvia; Margonelli, Andrea; Rea, Giuseppina

    2015-09-01

    A critical mass of knowledge is emerging on the interactions between plant cells and engineered nanomaterials, revealing the potential of plant nanobiotechnology to promote and support novel solutions for the development of a competitive bioeconomy. This knowledge can foster the adoption of new methodological strategies to empower the large-scale production of biomass from commercially important microalgae. The present review focuses on the potential of carbon nanotubes (CNTs) to enhance photosynthetic performance of microalgae by (i) widening the spectral region available for the energy conversion reactions and (ii) increasing the tolerance of microalgae towards unfavourable conditions occurring in mass production. To this end, current understanding on the mechanisms of uptake and localization of CNTs in plant cells is discussed. The available ecotoxicological data were used in an attempt to assess the feasibility of CNT-based applications in algal biotechnology, by critically correlating the experimental conditions with the observed adverse effects. Furthermore, main structural and physicochemical properties of single- and multi-walled CNTs and common approaches for the functionalization and characterization of CNTs in biological environment are presented. Here, we explore the potential that nanotechnology can offer to enhance functions of algae, paving the way for a more efficient use of photosynthetic algal systems in the sustainable production of energy, biomass and high-value compounds.

  10. Characterization of the Kootenai River Algae Community and Primary Productivity Before and After Experimental Nutrient Addition, 2004–2007 [Chapter 2, Kootenai River Algal Community Characterization, 2009 KTOI REPORT].

    SciTech Connect

    Holderman, Charlie; Anders, Paul; Shafii, Bahman

    2009-07-01

    The Kootenai River ecosystem (spelled Kootenay in Canada) has experienced numerous ecological changes since the early 1900s. Some of the largest impacts to habitat, biological communities, and ecological function resulted from levee construction along the 120 km of river upstream from Kootenay Lake, completed by the 1950s, and the construction and operation of Libby Dam on the river near Libby Montana, completed in 1972. Levee construction isolated tens of thousands of hectares of historic functioning floodplain habitat from the river channel downstream in Idaho and British Columbia (B.C.) severely reducing natural biological productivity and habitat diversity crucial to large river-floodplain ecosystem function. Libby Dam greatly reduces sediment and nutrient transport to downstream river reaches, and dam operations cause large changes in the timing, duration, and magnitude of river flows. These and other changes have contributed to the ecological collapse of the post-development Kootenai River ecosystem and its native biological communities. In response to large scale loss of nutrients, experimental nutrient addition was initiated in the North Arm of Kootenay Lake in 1992, in the South Arm of Kootenay Lake in 2004, and in the Kootenai River at the Idaho-Montana border during 2005. This report characterizes baseline chlorophyll concentration and accrual (primary productivity) rates and diatom and algal community composition and ecological metrics in the Kootenai River for four years, one (2004) before, and three (2005 through 2007) after nutrient addition. The study area encompassed a 325 km river reach from the upper Kootenay River at Wardner, B.C. (river kilometer (rkm) 445) downstream through Montana and Idaho to Kootenay Lake in B.C. (rkm 120). Sampling reaches included an unimpounded reach furthest upstream and four reaches downstream from Libby Dam affected by impoundment: two in the canyon reach (one with and one without nutrient addition), a braided reach

  11. Algal cell disruption using microbubbles to localize ultrasonic energy

    PubMed Central

    Krehbiel, Joel D.; Schideman, Lance C.; King, Daniel A.; Freund, Jonathan B.

    2015-01-01

    Microbubbles were added to an algal solution with the goal of improving cell disruption efficiency and the net energy balance for algal biofuel production. Experimental results showed that disruption increases with increasing peak rarefaction ultrasound pressure over the range studied: 1.90 to 3.07 MPa. Additionally, ultrasound cell disruption increased by up to 58% by adding microbubbles, with peak disruption occurring in the range of 108 microbubbles/ml. The localization of energy in space and time provided by the bubbles improve efficiency: energy requirements for such a process were estimated to be one-fourth of the available heat of combustion of algal biomass and one-fifth of currently used cell disruption methods. This increase in energy efficiency could make microbubble enhanced ultrasound viable for bioenergy applications and is expected to integrate well with current cell harvesting methods based upon dissolved air flotation. PMID:25311188

  12. Autonomous benthic algal cultivator under feedback control of ecosystem metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An autonomous and internally-controlled techno-ecological hybrid was developed that controls primary production of algae in a laboratory-scale cultivator. The technoecosystem is based on an algal turf scrubber (ATS) system that combines engineered feedback control programming with internal feedback...

  13. First description of French V. tubiashii strains pathogenic to mollusk: II. Characterization of properties of the proteolytic fraction of extracellular products.

    PubMed

    Mersni-Achour, Rachida; Imbert-Auvray, Nathalie; Huet, Valérie; Ben Cheikh, Yosra; Faury, Nicole; Doghri, Ibtissem; Rouatbi, Sonia; Bordenave, Stéphanie; Travers, Marie-Agnès; Saulnier, Denis; Fruitier-Arnaudin, Ingrid

    2014-11-01

    Extracellular products (ECPs) of the French Vibrio tubiashii strain 07/118 T2 were previously reported to be toxic for the Pacific oyster Crassostrea gigas. In this study we now assessed host cellular immune responses and bacterial potential effectors by which these ECPs can be associated with host damages. The adhesion capacity (28% inhibition) and phagocytosis ability (56% inhibition) of oyster hemocytes were the main functions affected following in vitro contact between hemocytes and V. tubiashii ECPs. This may be linked to the demonstration of the capability of ECPs to cleave various cellular substrates as oyster collagen. Moreover, a strong metalloproteolytic activity was recorded with general (azocasein) and specific (ADAM) substrates and characterized by the use of standard inhibitors and metal ions. The addition of 1,10-phenanthroline and Zn2+ decreased proteolytic activity by about 80% and 50% respectively, confirming the presence of zinc metalloproteolytic activity in the ECPs. Mass spectrometry analyses of crude ECPs identified an extracellular zinc metalloprotease encoded by a gene with an open reading frame of 1821 bp (606 aa). Consensus zinc-binding motifs specific to thermolysin family and some glycosylation and phosphorylation sites were located on the deduced protein sequence. Taken together, our results suggest that this (these) zinc metalloprotease(s) might contribute to the impairment of hemocyte immunological functions; however, their direct involvement in ECPs toxicity remains to be demonstrated. PMID:25252078

  14. Secondary Metabolites from the Marine Algal-Derived Endophytic Fungi: Chemical Diversity and Biological Activity.

    PubMed

    Zhang, Peng; Li, Xin; Wang, Bin-Gui

    2016-06-01

    Marine algal-derived endophytic fungi have attracted considerable attention in the most recent two decades due to their prolific production of structurally diverse secondary metabolites with various biological activities. This review summarizes a total of 182 natural products isolated from marine algal-derived endophytic fungi in the past two decades. The emphasis is on the unique chemical diversity of these metabolic products, together with relevant biological activities.

  15. Production and properties of an extracellular bacteriocin from Streptococcus mutans bacteriocidal for group A and other streptococci.

    PubMed Central

    Paul, D; Slade, H D

    1975-01-01

    An extracellular bacteriocidal substance is produced by a serotype c strain of Streptococcus mutans in liquid meduim during the stationary phase of growth. The lethal effect of the substance was demonstrated by the decrease in viable counts of a standardized suspension of group A streptococci in broth. No lysis of affected cells was observed and no changes in appearance of these cells was seen in electron micrographs. The material was effective against certain strains of immmunological groups A, C, D, G, H, L, and O streptococci. It was inactive against strains of S. mutans belonging to the a, b, c, and d serotypes, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The factor was purified 273-fold from the culture fluid by column chromatography. It was sensitive to trysin and Pronase and resistant to catalase. It possessed a molecular weight of more than 20,000 and was not dialyzable. The properties of this substance indicate that it is a bacteriocin. Group A streptococci, which had been treated with antiserum specific for the cell wall group and type antigens, were susceptible to the bacteriocin. Streptococcal strains resistant to the lethal action of the bacteriocin adsorbed the bacteriocin from the solutions, as did the sensitive cells. The bacteriocin was not adsorbed at 0 C. Images PMID:1107225

  16. Toxicity induced enhanced extracellular matrix production in osteoblastic cells cultured on single-walled carbon nanotube networks.

    PubMed

    Tutak, Wojtek; Park, Ki Ho; Vasilov, Anatoly; Starovoytov, Valentin; Fanchini, Giovanni; Cai, Shi-Qing; Partridge, Nicola C; Sesti, Federico; Chhowalla, Manish

    2009-06-24

    A central effort in biomedical research concerns the development of materials for sustaining and controlling cell growth. Carbon nanotube based substrates have been shown to support the growth of different kinds of cells (Hu et al 2004 Nano Lett. 4 507-11; Kalbacova et al 2006 Phys. Status Solidi b 13 243; Zanello et al 2006 Nano Lett. 6 562-7); however the underlying molecular mechanisms remain poorly defined. To address the fundamental question of mechanisms by which nanotubes promote bone mitosis and histogenesis, primary calvariae osteoblastic cells were grown on single-walled carbon nanotube thin film (SWNT) substrates. Using a combination of biochemical and optical techniques we demonstrate here that SWNT networks promote cell development through two distinct steps. Initially, SWNTs are absorbed in a process that resembles endocytosis, inducing acute toxicity. Nanotube-mediated cell destruction, however, induces a release of endogenous factors that act to boost the activity of the surviving cells by stimulating the synthesis of extracellular matrix.

  17. Algal taxonomy forum: Algal Taxonomist, Let Serendipity Reign!

    PubMed

    Druehl, Louis

    2013-04-01

    The publication of a mini-review by Olivier De Clerck et al. in this issue of the Journal of Phycology presented an opportunity to open a dialogue on challenges faced by contemporary algal taxonomists. The Editorial Office solicited the following two additional contributions in response to De Clerck et al.'s paper; the responses were edited solely for clarity, space and format. PMID:27008510

  18. Effects of solar ultraviolet radiation on tropical algal communities

    SciTech Connect

    Santas, R.

    1989-01-01

    This study assessed some of the effects of solar ultraviolet (UV) radiation ion coral reef algal assemblages. The first part of the investigation was carried out under controlled laboratory conditions in the coral reef microcosm at the National Museum of Natural History in Washington, D.C., while a field counterpart was completed at the Smithsonian Institution's marine station on Grand Turk, Turks and Caicos Islands, in the eastern Caribbean. The study attempted to separate the effects of UV-A from those of UV-B. In the laboratory, algal turf assemblages exposed to simulated solar UV radiation produced 55.1% less biomass than assemblages that were not exposed to UV. Assemblages not exposed to UV were dominated by Ectocarpus rhodochondroides, whereas in the assemblage developing under high UV radiation, Enteromorpha prolifera and eventually Schizothrix calcicola dominated. Lower UV-B irradiances caused a proportional reduction in biomass production and had less pronounced effects on species composition. UV-A did not have any significant effects on either algal turf productivity or community structure. In the field, assemblages exposed to naturally occurring solar UV supported a biomass 40% lower than that of assemblages protected from UV-B exposure. Once again, UV-A did not inhibit algal turf productivity.

  19. Melanin production through novel processing of proopiomelanocortin in the extracellular compartment of the auricular skin of C57BL/6 mice after UV-irradiation.

    PubMed

    Yamamoto, Hiroyuki; Yamane, Tomohiro; Iguchi, Kazuaki; Tanaka, Kiyotaka; Iddamalgoda, Arunasiri; Unno, Keiko; Hoshino, Minoru; Takeda, Atsushi

    2015-09-29

    The production of melanin is regulated by α-melanocyte-stimulating hormone (α-MSH), which is produced from proopiomelanocortin (POMC). Keratinocytes release POMC along with lower levels of α-MSH and ACTH. To clarify the mechanism of melanogenesis after ultraviolet (UV)-irradiation, this study focused on the expression of POMC and POMC-derived peptides after UV-irradiation. Western blot analysis and immunoassays indicated that both POMC and α-MSH-like immunoreactivity (α-MSH-LI) increased after UV-irradiation. However, other POMC-derived products were very low. In hypophysectomized mice, α-MSH-LI increased to the same level as in control mice after UV-irradiation. Structural analysis revealed that the major α-MSH-LI product was ACTH(1-8). Furthermore, ACTH(1-8) competed with [(125)I]-α-MSH for receptor binding and increased melanin production via a melanocortin-1 receptor. These results suggested that melanin was produced through ACTH(1-8) after UV-irradiation. Trypsin-like enzymatic activity, which is responsible for POMC activation, increased after UV-irradiation and was identified as tryptase. In mast cell-deficient mice, which do not produce tryptase, α-MSH-LI levels were unchanged after UV-irradiation. The present study demonstrates the production of ACTH(1-8) from POMC by tryptase, which is a novel peptide-processing mechanism in the extracellular compartment of the skin.

  20. Algal Pretreatment Improves Biofuels Yield and Value; Highlights in Science, NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-05-15

    One of the major challenges associated with algal biofuels production in a biorefinery-type setting is improving biomass utilization in its entirety, increasing the process energetic yields and providing economically viable and scalable co-product concepts. We demonstrate the effectiveness of a novel, integrated technology based on moderate temperatures and low pH to convert the carbohydrates in wet algal biomass to soluble sugars for fermentation, while making lipids more accessible for downstream extraction and leaving a protein-enriched fraction behind. This research has been highlighted in the Green Chemistry journal article mentioned above and a milestone report, and is based on the work the researchers are doing for the AOP projects Algal Biomass Conversion and Algal Biofuels Techno-economic Analysis. That work has demonstrated an advanced process for algal biofuel production that captures the value of both the algal lipids and carbohydrates for conversion to biofuels.  With this process, as much as 150 GGE/ton of biomass can be produced, 2-3X more than can be produced by terrestrial feedstocks.  This can also reduce the cost of biofuel production by as much as 40%. This also represents the first ever design case for the algal lipid upgrading pathway.

  1. Algal blooms and public health

    SciTech Connect

    Epstein, P.R. . Harvard Medical School)

    1993-06-01

    Alterations in coastal ecology are expanding the geographic extent, frequency, magnitude, and species complexity'' of algal blooms throughout the world, increasing the threat of fish and shellfish poisonings, anoxia in marine nurseries, and of cholera. The World Health Organization and members of the medical profession have described the potential health effects of global climate change. They warn of the consequences of increased ultraviolet-B (UV-B) rays and of warming: the possible damage to agriculture and nutrition, and the impact on habitats which may alter the distribution of vector-borne and water-based infectious diseases. Algal growth due to increased nitrogen (N) and phosphorus (P) and warming are already affecting marine microflora and aquatic plants; and there is now clear evidence that marine organisms are a reservoir for enteric pathogens. The pattern of cholera in the Western Hemisphere suggests that environmental changes have already begun to influence the epidemiology of this infectious disease. 106 refs.

  2. Effect of linoleic acid sustained-release microspheres on Microcystis aeruginosa antioxidant enzymes activity and microcystins production and release.

    PubMed

    Ni, Lixiao; Jie, Xiaoting; Wang, Peifang; Li, Shiyin; Wang, Guoxiang; Li, Yiping; Li, Yong; Acharya, Kumud

    2015-02-01

    The objective of this work was to identify the optimal dose range for good anti-algal effect of linoleic acid (LA) sustained-release microspheres and investigate their impact on the antioxidant enzymes (super oxide dismutase, Catalase and Peroxidase) activity changes of Microcystis aeruginosa, as well as the production and release of microcystins (MCs). Based on measured changes in algal cell density and inhibitory ratio (IR), the optimal dose of LA microspheres was 0.3 g L(-1) with over 90% of IR in this study. The Chlorophyll a content and antioxidant enzymes activity in the LA microspheres group decreased markedly until beyond the minimal detection limit after 16 d and 9 d, respectively. In addition, LA microspheres demonstrated no significant impact on the extracellular release of MCs during the culturing period. The amount of intracellular microcystin-LR (MC-LR) per 10(6) algal cells in LA microspheres group was highest among all groups during the whole experimental process. Under the sustained stress of LA released from LA microspheres, the LA microspheres could decrease the production and release of algal toxins. There was no increase in the total amount of MC-LR in the algal cell culture medium. These indicated that LA sustained-release microspheres represent a high degree of ecological safety and their practical applications for the treatment of water undergoing algal blooms need further study.

  3. Production of extracellular traps against Aspergillus fumigatus in vitro and in infected lung tissue is dependent on invading neutrophils and influenced by hydrophobin RodA.

    PubMed

    Bruns, Sandra; Kniemeyer, Olaf; Hasenberg, Mike; Aimanianda, Vishukumar; Nietzsche, Sandor; Thywissen, Andreas; Jeron, Andreas; Latgé, Jean-Paul; Brakhage, Axel A; Gunzer, Matthias

    2010-04-29

    Aspergillus fumigatus is the most important airborne fungal pathogen causing life-threatening infections in immunocompromised patients. Macrophages and neutrophils are known to kill conidia, whereas hyphae are killed mainly by neutrophils. Since hyphae are too large to be engulfed, neutrophils possess an array of extracellular killing mechanisms including the formation of neutrophil extracellular traps (NETs) consisting of nuclear DNA decorated with fungicidal proteins. However, until now NET formation in response to A. fumigatus has only been demonstrated in vitro, the importance of neutrophils for their production in vivo is unclear and the molecular mechanisms of the fungus to defend against NET formation are unknown. Here, we show that human neutrophils produce NETs in vitro when encountering A. fumigatus. In time-lapse movies NET production was a highly dynamic process which, however, was only exhibited by a sub-population of cells. NETosis was maximal against hyphae, but reduced against resting and swollen conidia. In a newly developed mouse model we could then demonstrate the existence and measure the kinetics of NET formation in vivo by 2-photon microscopy of Aspergillus-infected lungs. We also observed the enormous dynamics of neutrophils within the lung and their ability to interact with and phagocytose fungal elements in situ. Furthermore, systemic neutrophil depletion in mice almost completely inhibited NET formation in lungs, thus directly linking the immigration of neutrophils with NET formation in vivo. By using fungal mutants and purified proteins we demonstrate that hydrophobin RodA, a surface protein making conidia immunologically inert, led to reduced NET formation of neutrophils encountering Aspergillus fungal elements. NET-dependent killing of Aspergillus-hyphae could be demonstrated at later time-points, but was only moderate. Thus, these data establish that NET formation occurs in vivo during host defence against A. fumigatus, but suggest

  4. Improving production of extracellular proteases by random mutagenesis and biochemical characterization of a serine protease in Bacillus subtilis S1-4.

    PubMed

    Wang, X C; Zhao, H Y; Liu, G; Cheng, X J; Feng, H

    2016-01-01

    The feather is a valuable by-product with a huge annual yield produced by the poultry industry. Degradation of feathers by microorganisms is a prerequisite to utilize this insoluble protein resource. To improve the degrading efficiency of feathers, mutagenesis of the bacterium Bacillus subtilis S1-4 was performed. By combining ultraviolet irradiation and N-methyl-N'-nitro-N-nitrosoguanidine treatment for mutagenesis, a high protease-producing mutant (UMU4) of B. subtilis S1-4 was selected, which exhibited 2.5-fold higher extracellular caseinolytic activity than did the wild-type strain. UMU4 degraded chicken feathers more efficiently, particularly for the release of soluble proteins from the feathers, compared to the wild-type strain. Furthermore, an extracellular protease with a molecular weight of 45 kDa, as determined by SDS-PAGE, was purified from UMU4. Biochemical characterization indicated that the caseinolytic activity of the protease was largely inhibited by phenylmethanesulfonyl fluoride, suggesting that the purified enzyme is a serine protease. This protease was highly active over a wide range of pHs (6.0 to 12.0) and temperatures (50° to 75°C) with an optimal pH and temperature of 8.0 and 65°C, respectively. The purified enzyme exhibited good thermostability with a 72.2 min half-life of thermal denaturation at 60°C. In addition, this protease was not sensitive to heavy metal ions, surfactants, or oxidative reagents. In conclusion, strain improvement for protease production can serve as an alternative strategy to promote feather degradation. The UMU4 mutant of B. subtilis and its serine protease could be potentially used in various industries. PMID:27323184

  5. Fumigaclavine C improves concanavalin A-induced liver injury in mice mainly via inhibiting TNF-alpha production and lymphocyte adhesion to extracellular matrices.

    PubMed

    Zhao, Ying; Liu, Junyan; Wang, Jun; Wang, Lei; Yin, Hao; Tan, Renxiang; Xu, Qiang

    2004-06-01

    Fumigaclavine C, an alkaloidal metabolite, was produced by Aspergillus fumigatus (strain No. CY018). This study examined the effect of this compound on concanavalin A (Con A)-induced liver injury in mice, a T cell-dependent model of liver damage. Con A administration resulted in severe liver injury, T lymphocyte activation and a strong increment in spleen cell adhesion, as well as in tumour necrosis factor-alpha (TNF-alpha) production. Against this liver injury, the intraperitoneal administration of fumigaclavine C dose-dependently inhibited the elevation in transaminase activity, TNF-alpha production in serum and the histological changes, including inflammatory infiltration, hepatocyte necrosis and degeneration and Kupffer cell hyperplasia. In addition, this compound in-vitro also inhibited the proliferation of spleen cells induced by Con A, and reduced their IL-2 and TNF-alpha production. Moreover, the intraperitoneal administration of fumigaclavine C inhibited the potential of spleen cells isolated from the liver-injured mice to adhere to fibronectin, laminin and type IV collagen. These results suggest that the improvement of this T cell-mediated liver injury by fumigaclavine C may be related to the inhibition of lymphocyte activation, proliferation and adhesion to extracellular matrices as well as the reduction in TNF-alpha production. PMID:15231043

  6. Algal Biofuels Factsheet: Long-Term Energy Benefits Drive U.S. Research

    SciTech Connect

    2013-03-04

    Algal biofuels are generating considerable interest around the world. In the United States, they represent promising pathways for helping to meet the biofuel production targets set by the Energy Independence and Security Act of 2007.

  7. Mechanism of Algal Aggregation by Bacillus sp. Strain RP1137

    PubMed Central

    Powell, Ryan J.

    2014-01-01

    Alga-derived biofuels are one of the best alternatives for economically replacing liquid fossil fuels with a fungible renewable energy source. Production of fuel from algae is technically feasible but not yet economically viable. Harvest of dilute algal biomass from the surrounding water remains one of the largest barriers to economic production of algal biofuel. We identified Bacillus sp. strain RP1137 in a previous study and showed that this strain can rapidly aggregate several biofuel-producing algae in a pH- and divalent-cation-dependent manner. In this study, we further characterized the mechanism of algal aggregation by RP1137. We show that aggregation of both algae and bacteria is optimal in the exponential phase of growth and that the density of ionizable residues on the RP1137 cell surface changes with growth stage. Aggregation likely occurs via charge neutralization with calcium ions at the cell surface of both algae and bacteria. We show that charge neutralization occurs at least in part through binding of calcium to negatively charged teichoic acid residues. The addition of calcium also renders both algae and bacteria more able to bind to hydrophobic beads, suggesting that aggregation may occur through hydrophobic interactions. Knowledge of the aggregation mechanism may enable engineering of RP1137 to obtain more efficient algal harvesting. PMID:24771029

  8. Harmful algal toxins of the Florida red tide (Karenia brevis): natural chemical stressors in South Florida coastal ecosystems

    PubMed Central

    Henry, M. S.

    2009-01-01

    The Florida red tide is a descriptive name for high concentrations of the harmful marine alga, Karenia brevis. Although most prevalent along the south-west Florida coast, periodic blooms have occurred throughout the entire US and Mexico Gulf coasts and the Atlantic coast to North Carolina. This dinoflagellate produces a suite of polyether neurotoxins, called brevetoxins, that cause severe impacts to natural resources, as well as public health. These naturally produced biotoxins may represent one of the most common chemical stressors impacting South Florida coastal and marine ecosystems. Impacts include massive fish kills, marine mammal, sea turtle and sea bird mortalities, benthic community die-off and public health effects from shellfish contamination and inhalation of air-borne toxins. The primary mode of action is binding to voltage-gated sodium channels causing depolarization of nerve cells, thus interfering with nerve transmission. Other effects include immune depression, bronchial constriction and haemolysis. Parent algal toxins are synthesized within the unicellular organism, others are produced as metabolic products. Recent studies into the composition of brevetoxins in cells, water, air and organisms have shown PbTx-2 to be the primary intracellular brevetoxin that is converted over time to PbTx-3 when the cells are ruptured, releasing extracellular brevetoxins into the environment. Brevetoxins become aerosolized by bubble-mediated transport of extracellular toxins, the composition of which varies depending on the composition in the source water. Bivalved molluscs rapidly accumulate brevetoxins as they filter feed on K. brevis cells. However, the parent algal toxins are rapidly metabolized to other compounds, some of which are responsible for neurotoxic shellfish poisoning (NSP). These results provide new insight into the distribution, persistence and impacts of red tide toxins to south-west Florida ecosystems. PMID:18758951

  9. Comparative genomic analysis of Geobacter sulfurreducens KN400, a strain with enhanced capacity for extracellular electron transfer and electricity production

    PubMed Central

    2012-01-01

    Background A new strain of Geobacter sulfurreducens, strain KN400, produces more electrical current in microbial fuel cells and reduces insoluble Fe(III) oxides much faster than the wildtype strain, PCA. The genome of KN400 was compared to wildtype with the goal of discovering how the network for extracellular electron transfer has changed and how these two strains evolved. Results Both genomes were re-annotated, resulting in 14 fewer genes (net) in the PCA genome; 28 fewer (net) in the KN400 genome; and ca. 400 gene start and stop sites moved. 96% of genes in KN400 had clear orthologs with conserved synteny in PCA. Most of the remaining genes were in regions of genomic mobility and were strain-specific or conserved in other Geobacteraceae, indicating that the changes occurred post-divergence. There were 27,270 single nucleotide polymorphisms (SNP) between the genomes. There was significant enrichment for SNP locations in non-coding or synonymous amino acid sites, indicating significant selective pressure since the divergence. 25% of orthologs had sequence differences, and this set was enriched in phosphorylation and ATP-dependent enzymes. Substantial sequence differences (at least 12 non-synonymous SNP/kb) were found in 3.6% of the orthologs, and this set was enriched in cytochromes and integral membrane proteins. Genes known to be involved in electron transport, those used in the metabolic cell model, and those that exhibit changes in expression during growth in microbial fuel cells were examined in detail. Conclusions The improvement in external electron transfer in the KN400 strain does not appear to be due to novel gene acquisition, but rather to changes in the common metabolic network. The increase in electron transfer rate and yield in KN400 may be due to changes in carbon flux towards oxidation pathways and to changes in ATP metabolism, both of which indicate that the overall energy state of the cell may be different. The electrically conductive pili appear

  10. Extracellular production of a glycolipid biosurfactant, mannosylerythritol lipid, by Candida sp. SY16 using fed-batch fermentation.

    PubMed

    Kim, Hee-Sik; Jeon, Jong-Woon; Kim, Byung-Hyuk; Ahn, Chi-Yong; Oh, Hee-Mock; Yoon, Byung-Dae

    2006-04-01

    Candida sp. strain SY16 produces a glycolipid-type biosurfactant, mannosylerythritol lipid (MEL-SY16), which can reduce the surface tension of a culture broth from 72 to 30 dyne cm(-1) and highly emulsify hydrocarbons when cultured in soybean-oil-containing media. As such, laboratory-scale fermentation for MEL-SY16 production was performed using optimized conditions. In batch fermentation, MEL-SY16 was mainly produced during the stationary phase of growth, and the concentration of MEL-SY16 reached 37 g l(-1) after 200 h. The effect of pH control on the production of MEL-SY16 was also examined in batch fermentation. The highest production yield of MEL-SY16 was when the pH was controlled at 4.0, and the production was significantly improved compared to batch fermentation without pH control. In fed-batch fermentation, glucose and soybean oil (1:1, w/w) were used in combination as the initial carbon sources for cell growth, and soybean oil was used as the feeding carbon source during the MEL production phase. The feeding of soybean oil resulted in the disappearance of any foam and a sharp increase in the MEL production until 200 h, at which point the concentration of MEL-SY16 was 95 g l(-1). Among the investigated culture systems, the highest MEL-SY16 production and volumetric production rate were achieved with fed-batch fermentation. PMID:16133323

  11. Review of the algal biology program within the National Alliance for Advanced Biofuels and Bioproducts

    DOE PAGES

    Unkefer, Clifford Jay; Sayre, Richard Thomas; Magnuson, Jon K.; Anderson, Daniel B.; Baxter, Ivan; Blaby, Ian K.; Brown, Judith K.; Carleton, Michael; Cattolico, Rose Ann; Dale, Taraka T.; et al

    2016-06-21

    In 2010,when the National Alliance for Advanced Biofuels and Bioproducts (NAABB) consortium began, little was known about the molecular basis of algal biomass or oil production. Very few algal genome sequences were available and efforts to identify the best-producing wild species through bioprospecting approaches had largely stalled after the U.S. Department of Energy's Aquatic Species Program. This lack of knowledge included how reduced carbon was partitioned into storage products like triglycerides or starch and the role played by metabolite remodeling in the accumulation of energy-dense storage products. Furthermore, genetic transformation and metabolic engineering approaches to improve algal biomass and oilmore » yields were in their infancy. Genome sequencing and transcriptional profiling were becoming less expensive, however; and the tools to annotate gene expression profiles under various growth and engineered conditions were just starting to be developed for algae. It was in this context that an integrated algal biology program was introduced in the NAABB to address the greatest constraints limiting algal biomass yield. Our review describes the NAABB algal biology program, including hypotheses, research objectives, and strategies to move algal biology research into the twenty-first century and to realize the greatest potential of algae biomass systems to produce biofuels.« less

  12. Identification of naturally isolated southern Louisiana's algal strains and the effect of higher Co2 content on fatty acid profiles for biodiesel production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four naturally isolated microalgae were evaluated for their potential use in the production of biodiesel, and were identified using genomic DNA, and 16S or 18S rRNA gene amplification followed by sequencing. High correlation was found with known nucleotide sequence identities at 98 % with Sellaphora...

  13. Shallow Algal Mass Culture Systems for the Production of Oils: Final Report on Work Carried Out 8/16/84 - 6/15/85

    SciTech Connect

    Laws, E. A.

    1985-01-01

    The objective of this project was to improve the technology of outdoor mass culture of microa1gae for oil production by investigation of species/strains, optimization of culture conditions and development of strategies that increase efficiency and improve yield.

  14. Extracellular beta-glucosidase production by the yeast Debaryomyces pseudopolymorphus UCLM-NS7A: optimization using response surface methodology.

    PubMed

    Barbosa, Aneli M; Giese, Ellen C; Dekker, Robert F H; Borsato, Dionísio; Briones Pérez, Ana I; Ubeda Iranzo, Juan F

    2010-09-30

    beta-Glucosidase production by Debaryomyces pseudopolymorphus UCLM-NS7A using a simple nutrient medium containing cellobiose was evaluated under several biochemical and physiological parameters in submerged fermentation. Enzyme induction was also examined using different carbon and nitrogen sources. Cellobiose and ammonium nitrate were the best C and N sources to enhance beta-glucosidase production. The addition of NaCl, MgSO(4), yeast extract, ethanol and Tween 80 to the nutrient medium before inoculation was also compared. A factorial design to optimize enzyme production was developed using four variables that most influenced beta-glucosidase production and data analyzed by the response surface method. Optimal conditions to produce beta-glucosidase in shake-flasks were 1.25% cellobiose, 0.05% Tween 80, 0.4% NH(4)NO(3) over 72 hours. In another factorial design to further increase enzyme production, a lab fermenter using prior-determined shake-flask optimized conditions resulted in higher beta-glucosidase titres at 72 hours, pH controlled at 6.25 and agitation of 200 rpm. PMID:20493976

  15. Induction of cytokine production in cholesteatoma keratinocytes by extracellular high-mobility group box chromosomal protein 1 combined with DNA released by apoptotic cholesteatoma keratinocytes.

    PubMed

    Chi, Zhangcai; Wang, Zhengmin; Liang, Qiong; Zhu, Yaying; du, Qiang

    2015-02-01

    High-mobility group box chromosomal protein 1 (HMGB-1), a nuclear DNA binding protein, was recently rediscovered as a new proinflammatory cytokine. The purpose of this study was to determine HMGB-1 expression in vivo and to identify the effect of extracellular HMGB-1 in inflammatory process associated with bone destruction in cholesteatoma. We investigated the expression and location of HMGB-1 in the cholesteatoma and healthy skin using an immunofluorescence assay. We also detected apoptosis and DNA fragments in the cholesteatoma by TUNEL staining. HMGB-1 concentration in apoptotic supernatants from UV light-treated cells, culture supernatants and its translocation in cholesteatoma keratinocytes stimulated by supernatants from UV light-treated cells were measured by immunoblot analysis and immunofluorescence assay. Cultures of human cholesteatoma keratinocytes were exposed to CpG-DNA, HMGB-1, or CpG-DNA complexed to HMGB-1 for 24 h. Cytokines in the culture supernatant were measured by ELISA. In addition, levels of proinflammatory cytokines released by cholesteatoma keratinocytes stimulated by supernatants from UV light-treated cells with or without anti-HMGB-1 antibodies and supernatants from UV light-treated cells with DNase 1 were measured by enzyme-linked immunosorbent assay. The expression of HMGB-1 in cholesteatoma increased and it translocated both to the cytoplasm and extracellular space. Furthermore, the HMGB-1 concentration in supernatants increased significantly after addition of supernatants from UV light-treated cells. TNF-α and IL-1β can be induced by purified HMGB-1 combined with CpG-DNA in the cholesteatoma keratinocytes. In addition, supernatants of apoptotic cells containing HMGB-1-DNA were effective in inducing TNF-α and IL-1β secretion. This study suggested that persistent expression of extracellular HMGB-1 and DNA fragments in cholesteatoma leads to TNF-α and IL-1β production, causing bone resorption and destruction. Thus, we have

  16. Proteins of novel lactic acid bacteria from Apis mellifera mellifera: an insight into the production of known extra-cellular proteins during microbial stress

    PubMed Central

    2013-01-01

    Background Lactic acid bacteria (LAB) has been considered a beneficial bacterial group, found as part of the microbiota of diverse hosts, including humans and various animals. However, the mechanisms of how hosts and LAB interact are still poorly understood. Previous work demonstrates that 13 species of Lactobacillus and Bifidobacterium from the honey crop in bees function symbiotically with the honeybee. They protect each other, their hosts, and the surrounding environment against severe bee pathogens, bacteria, and yeasts. Therefore, we hypothesized that these LAB under stress, i.e. in their natural niche in the honey crop, are likely to produce bioactive substances with antimicrobial activity. Results The genomic analysis of the LAB demonstrated varying genome sizes ranging from 1.5 to 2.2 mega-base pairs (Mbps) which points out a clear difference within the protein gene content, as well as specialized functions in the honeybee microbiota and their adaptation to their host. We demonstrate a clear variation between the secreted proteins of the symbiotic LAB when subjected to microbial stressors. We have identified that 10 of the 13 LAB produced extra-cellular proteins of known or unknown function in which some are arranged in interesting putative operons that may be involved in antimicrobial action, host interaction, or biofilm formation. The most common known extra-cellular proteins secreted were enzymes, DNA chaperones, S-layer proteins, bacteriocins, and lysozymes. A new bacteriocin may have been identified in one of the LAB symbionts while many proteins with unknown functions were produced which must be investigated further. Conclusions The 13 LAB symbionts likely play different roles in their natural environment defending their niche and their host and participating in the honeybee’s food production. These roles are partly played through producing extracellular proteins on exposure to microbial stressors widely found in natural occurring flowers. Many of

  17. Screening of Coprinus species for the production of extracellular peroxidase and evaluation of the enzyme for the treatment of aqueous phenol.

    PubMed

    Ikehata, K; Buchanan, I D

    2002-12-01

    The production of extracellular peroxidase by twenty-five strains of Coprinus species was investigated for the purpose of its application to the removal of phenolic and other aromatic compounds from industrial waste streams. After initial screening experiments, the production of peroxidase by three superior strains of C cinererus UAMH 4103, UAMH 7907 and IFO 30116 was monitored over a 15-day period. Peroxidase activity was detected after 3 days of growth and had reached itspeak another 6 days later. The peroxidase activity appeared to increase with a corresponding depletion of glucose concentration and rapidly declined immediately after the exhaustion of glucose. The effectiveness of the cultivated C. cinereus peroxidase (CIP) for the removal of aqueous phenol was evaluated in the presence and in the absence of additives including polyethylene glycol (PEG) and chitosan, and compared with those of purified horseradish peroxidase (HRP) and Arthromyces ramosus peroxidase (ARP). The addition of PEG and chitosan enhanced the efficiency of phenol transformation catalyzed by CIP by the factor of 1.5 and 1.3, respectively. Although the efficiency of phenol transformation was higher with CIP than those with purified HRP and ARP in the absence of addtives, its superiority diminished in the presence of PEG. This suggests that the by-products of fungal culture in the crude CIP solution, presumably polycarbohydrates and proteins, have protective effects on the enzyme against inactivation during catalytic transformation of phenol, and the addition of PEG provides small effects on further protection.

  18. Tris-sucrose buffer system: a new specially designed medium for extracellular invertase production by immobilized cells of isolated yeast Cryptococcus laurentii MT-61.

    PubMed

    Aydogan, Mehmet Nuri; Taskin, Mesut; Canli, Ozden; Arslan, Nazli Pinar; Ortucu, Serkan

    2014-01-01

    The aims of the present study were to isolate new yeasts with high extracellular (exo) invertase activity and to investigate the usability of buffer systems as invertase production media by immobilized yeast cells. Among 70 yeast isolates, Cryptococcus laurentii MT-61 had the highest exo-invertase activity. Immobilization of yeast cells was performed using sodium alginate. Higher exo-invertase activity for immobilized cells was achieved in tris-sucrose buffer system (TSBS) compared to sodium acetate buffer system and potassium phosphate buffer system. TSBS was prepared by dissolving 30 g of sucrose in 1 L of tris buffer solution. The optimum pH, temperature, and incubation time for invertase production with immobilized cells were determined as 8.0, 35 °C and 36 h in TSBS, respectively. Under optimized conditions, maximum exo-invertase activity was found to be 28.4 U/mL in sterile and nonsterile TSBS. Immobilized cells could be reused in 14 and 12 successive cycles in sterile and nonsterile TSBS without any loss in the maximum invertase activity, respectively. This is the first report which showed that immobilized microbial cells could be used as a biocatalyst for exo-invertase production in buffer system. As an additional contribution, a new yeast strain with high invertase activity was isolated.

  19. Production of extra-cellular slime by Staphylococcus epidermidis during stationary phase of growth: its association with adherence to implantable devices.

    PubMed

    Bayston, R; Rodgers, J

    1990-10-01

    A method of optimising slime production produced by Staphylococcus epidermis and its quantitative assay was developed, which gave a preliminary indication of its identity and an assessment of the correlation between slime production and adherence of the organism to implants. After inducing vigorous growth in brain heart infusion broth to stationary phase, all nutrients were removed by washing and the organisms resuspended in sterile deionised water with added magnesium. After further incubation the culture was centrifuged and the supernatant reacted with alcian blue in 50 mM magnesium chloride/sodium acetate solution, and the amount of bound dye was measured spectrophotometrically at 620 nm after its resolubilisation using sodium dodecyl sulphate. Large quantities of slime were produced by some, but not all, strains. Preliminary electrophoresis of the slime showed mobility and staining similar to that of the glycosaminoglycans. Adherence was tested by growing strains in wells of tissue culture plates and aspirating the supernatant after incubation. After fixation and staining of adherent growth the amount of bound stain was determined spectrophotometrically after its elution with ethanol. In this series of organisms there was no correlation between the result of tests for adherence or production of extracellular slime, and no correlation between either of these and the clinical source of the organisms. PMID:2229437

  20. Partial characterization and optimization of production of extracellular alpha-amylase from Bacillus subtilis isolated from culturable cow dung microflora.

    PubMed

    Swain, Manas R; Kar, Shaktimay; Padmaja, Gourikutti; Ray, Ramesh C

    2006-01-01

    Studies of alpha-amylase production by Bacillus subtilis (CM3) isolated earlier from cow dung microflora, were carried out. The optimum temperature, pH and incubation period for amylase production were 50-70 degrees C, 5.0-9.0 and 36 h, respectively. Enzyme secretion was very similar in the presence of any of the carbon sources tested (soluble starch, potato starch, cassava starch, wheat flour, glucose, fructose, etc.). Yeast extract and ammonium acetate (1%) as nitrogen sources gave higher yield compared to other nitrogen sources (peptone, malt extract, casein, asparagine, glycine, beef extract), whereas ammonium chloride, ammonium sulphate and urea inhibited the enzyme activity. Addition of Ca+2 (10-40 mM) to the culture medium did not result in further improvement of enzyme production, whereas the addition of surfactants (Tween 20, Tween 40, Tween 80, and sodium lauryl sulphate) at 0.02% resulted in 2-15% increase in enzyme production. There were no significant variations in enzyme yield between shaked-flask and laboratory fermentor cultures. The purified enzyme is in two forms with molecular mass of 18.0 +/- 1 and 43.0 +/- 1 kDa in native SDS-PAGE.

  1. Mechanical algal disruption for efficient biodiesel extraction

    NASA Astrophysics Data System (ADS)

    Krehbiel, Joel David

    sensitivity to the viscosity of the interior fluid than the average areal strain. Overall, the dissertation lays the groundwork for more efficient algal disruption through the judicious use of microbubbles. Separation of bubble generation and bubble growth provides the ability to improve the efficiency of each process and localize energy. Results suggest that effective disruption can occur by pulsing high-pressure ultrasound waves to a solution of cells co-suspended with microbubbles. The models are thought to represent basic phenomenological mechanisms of disruption that could be exploited to improve the overall energy efficiency of schemes. Analysis suggests that extensional flow alone cannot be the cause of cell disruption near an expanding microbubble. Additionally, this work provides an estimate of the areal strain required disrupt an algal cell membrane. This research suggests a couple routes toward reducing the energy required for production of algal biodiesel.

  2. Growth and fatty acid characterization of microalgae isolated from municipal waste-treatment systems and the potential role of algal-associated bacteria in feedstock production.

    PubMed

    Stemmler, Kevin; Massimi, Rebecca; Kirkwood, Andrea E

    2016-01-01

    Much research has focused on growing microalgae for biofuel feedstock, yet there remain concerns about the feasibility of freshwater feedstock systems. To reduce cost and improve environmental sustainability, an ideal microalgal feedstock system would be fed by municipal, agricultural or industrial wastewater as a main source of water and nutrients. Nonetheless, the microalgae must also be tolerant of fluctuating wastewater quality, while still producing adequate biomass and lipid yields. To address this problem, our study focused on isolating and characterizing microalgal strains from three municipal wastewater treatment systems (two activated sludge and one aerated-stabilization basin systems) for their potential use in biofuel feedstock production. Most of the 19 isolates from wastewater grew faster than two culture collection strains under mixotrophic conditions, particularly with glucose. The fastest growing wastewater strains included the genera Chlorella and Dictyochloris. The fastest growing microalgal strains were not necessarily the best lipid producers. Under photoautotrophic and mixotrophic growth conditions, single strains of Chlorella and Scenedesmus each produced the highest lipid yields, including those most relevant to biodiesel production. A comparison of axenic and non-axenic versions of wastewater strains showed a notable effect of commensal bacteria on fatty acid composition. Strains grown with bacteria tended to produce relatively equal proportions of saturated and unsaturated fatty acids, which is an ideal lipid blend for biodiesel production. These results not only show the potential for using microalgae isolated from wastewater for growth in wastewater-fed feedstock systems, but also the important role that commensal bacteria may have in impacting the fatty acid profiles of microalgal feedstock. PMID:26989618

  3. Growth and fatty acid characterization of microalgae isolated from municipal waste-treatment systems and the potential role of algal-associated bacteria in feedstock production

    PubMed Central

    Stemmler, Kevin; Massimi, Rebecca

    2016-01-01

    Much research has focused on growing microalgae for biofuel feedstock, yet there remain concerns about the feasibility of freshwater feedstock systems. To reduce cost and improve environmental sustainability, an ideal microalgal feedstock system would be fed by municipal, agricultural or industrial wastewater as a main source of water and nutrients. Nonetheless, the microalgae must also be tolerant of fluctuating wastewater quality, while still producing adequate biomass and lipid yields. To address this problem, our study focused on isolating and characterizing microalgal strains from three municipal wastewater treatment systems (two activated sludge and one aerated-stabilization basin systems) for their potential use in biofuel feedstock production. Most of the 19 isolates from wastewater grew faster than two culture collection strains under mixotrophic conditions, particularly with glucose. The fastest growing wastewater strains included the genera Chlorella and Dictyochloris. The fastest growing microalgal strains were not necessarily the best lipid producers. Under photoautotrophic and mixotrophic growth conditions, single strains of Chlorella and Scenedesmus each produced the highest lipid yields, including those most relevant to biodiesel production. A comparison of axenic and non-axenic versions of wastewater strains showed a notable effect of commensal bacteria on fatty acid composition. Strains grown with bacteria tended to produce relatively equal proportions of saturated and unsaturated fatty acids, which is an ideal lipid blend for biodiesel production. These results not only show the potential for using microalgae isolated from wastewater for growth in wastewater-fed feedstock systems, but also the important role that commensal bacteria may have in impacting the fatty acid profiles of microalgal feedstock. PMID:26989618

  4. Harmful Algal Blooms and Public Health

    PubMed Central

    Grattan, Lynn M.; Holobaugh, Sailor; Morris, J. Glenn

    2015-01-01

    The five most commonly recognized Harmful Algal Bloom related illnesses include Ciguatera poisoning, Paralytic Shellfish poisoning, Neurotoxin Shellfish poisoning, Diarrheic Shellfish Poisoning and Amnesic Shellfish poisoning. Although they are each the product of different toxins, toxin assemblages or HAB precursors these clinical syndromes have much in common. Exposure occurs through the consumption of fish or shellfish; routine clinical tests are not available for diagnosis; there is no known antidote for exposure; and the risk of these illnesses can negatively impact local fishing and tourism industries. Thus, illness prevention is of paramount importance to minimize human and public health risks. To accomplish this, close communication and collaboration is needed among HAB scientists, public health researchers and local, state and tribal health departments at academic, community outreach, and policy levels. PMID:27616971

  5. Harmful Algal Blooms and Public Health

    PubMed Central

    Grattan, Lynn M.; Holobaugh, Sailor; Morris, J. Glenn

    2015-01-01

    The five most commonly recognized Harmful Algal Bloom related illnesses include Ciguatera poisoning, Paralytic Shellfish poisoning, Neurotoxin Shellfish poisoning, Diarrheic Shellfish Poisoning and Amnesic Shellfish poisoning. Although they are each the product of different toxins, toxin assemblages or HAB precursors these clinical syndromes have much in common. Exposure occurs through the consumption of fish or shellfish; routine clinical tests are not available for diagnosis; there is no known antidote for exposure; and the risk of these illnesses can negatively impact local fishing and tourism industries. Thus, illness prevention is of paramount importance to minimize human and public health risks. To accomplish this, close communication and collaboration is needed among HAB scientists, public health researchers and local, state and tribal health departments at academic, community outreach, and policy levels.

  6. Methods for removing contaminants from algal oil

    DOEpatents

    Lupton, Francis Stephen

    2016-09-27

    Methods for removing contaminants from algal oil are provided. In an embodiment, a method comprises the steps of combining a sulfuric acid-aqueous solution that has a pH of about 1 or less with a contaminant-containing algal oil at treatment conditions effective to form an effluent. The effluent comprises a treated algal oil phase and contaminants in an acidic aqueous phase. The contaminants comprise metals, phosphorus, or combinations thereof. The acidic aqueous phase is removed from the effluent to form a contaminant-depleted algal oil.

  7. Urban wastewater treatment by seven species of microalgae and an algal bloom: Biomass production, N and P removal kinetics and harvestability.

    PubMed

    Mennaa, Fatima Zahra; Arbib, Zouhayr; Perales, José Antonio

    2015-10-15

    This study evaluates the capacity of seven species and a Bloom of microalgae to grow in urban wastewater. Nutrient removal kinetics and biomass harvesting by means of centrifugation and coagulation-flocculation-sedimentation have been also tested. Results show that the best biomass productivities ranged from between 118 and 108 mgSS L(-1) d(-1) for the Bloom (Bl) and Scenedesmus obliquus (Sco). Regarding nutrient removal, microalgae were able to remove the total dissolved phosphorus and nitrogen concentrations by more than 80% and 87% respectively, depending on the species tested. The final total dissolved concentration of nitrogen and phosphorus in the culture media complies with the European Commission Directive 98/15/CE on urban wastewater treatment. Regarding harvesting, the results of coagulation-flocculation sedimentation using a 60 mg L(-1) dose of Ferric chloride were similar between species, exceeding the biomass removal efficiency by more than 90%. The results of centrifugation (time required to remove 90% of solids at 1000 rpm) were not similar between species, with the shortest time being 2.9 min for Sco, followed by the bloom (7.25 min). An overall analysis suggested that the natural bloom and Scenedesmus obliquus seem to be the best candidates to grow in pre-treated wastewater, according to their biomass production, nutrient removal capability and harvestability.

  8. Microtubule integrity regulates src-like and extracellular signal-regulated kinase activities in human pro-monocytic cells. Importance for interleukin-1 production.

    PubMed

    Schmid-Alliana, A; Menou, L; Manié, S; Schmid-Antomarchi, H; Millet, M A; Giuriato, S; Ferrua, B; Rossi, B

    1998-02-01

    We have demonstrated previously that microtubule depolymerization by colchicine in human monocytes induces selective production of interleukin-1 (IL-1) (Manié, S., Schmid-Alliana, A., Kubar, J., Ferrua, B., and Rossi, B. (1993) J. Biol. Chem. 268, 13675-13681). Here, we provide evidence that disruption of the microtubule structure rapidly triggers extracellular signal-regulated kinase (ERK) activation, whereas it was without effect on SAPK2 activity, which is commonly acknowledged to control pro-inflammatory cytokine production. This process involves the activation of the entire cascade including Ras, Raf-1, MEK1/2, ERK1, and ERK2. Activation of ERKs is followed by their nuclear translocation. Although other SAPK congeners might be activated upon microtubule depolymerization, the activation of ERK1 and ERK2 is mandatory for IL-1 production as shown by the blocking effect of PD 98059, a specific MEK1/2 inhibitor. Additionally, we provide evidence that microtubule disruption also induces the activation of c-Src and Hck activities. The importance of Src kinases in the mediation of the colchicine effect is underscored by the fact that CP 118556, a specific inhibitor of Src-like kinase, abrogates both the colchicine-induced ERK activation and IL-1 production. This is the first evidence that ERK activation is an absolute prerequisite for induction of this cytokine. Altogether, our data lend support to a model where the status of microtubule integrity controls the level of Src activities that subsequently activate the ERK kinase cascade, thus leading to IL-1 production.

  9. Antidepressants increase glial cell line-derived neurotrophic factor production through monoamine-independent activation of protein tyrosine kinase and extracellular signal-regulated kinase in glial cells.

    PubMed

    Hisaoka, Kazue; Takebayashi, Minoru; Tsuchioka, Mami; Maeda, Natsuko; Nakata, Yoshihiro; Yamawaki, Shigeto

    2007-04-01

    Recent studies show that neuronal and glial plasticity are important for therapeutic action of antidepressants. We previously reported that antidepressants increase glial cell line-derived neurotrophic factor (GDNF) production in rat C6 glioma cells (C6 cells). Here, we found that amitriptyline, a tricyclic antidepressant, increased both GDNF mRNA expression and release, which were selectively and completely inhibited by mitogen-activated protein kinase kinase inhibitors. Indeed, treatment of amitriptyline rapidly increased extracellular signal-regulated kinase (ERK) activity, as well as p38 mitogen-activated protein kinase and c-Jun NH2-terminal kinase activities. Furthermore, different classes of antidepressants also rapidly increased ERK activity. The extent of acute ERK activation and GDNF release were significantly correlated to each other in individual antidepressants, suggesting an important role of acute ERK activation in GDNF production. Furthermore, antidepressants increased the acute ERK activation and GDNF mRNA expression in normal human astrocytes as well as C6 cells. Although 5-hydroxytryptamine (serotonin) (5-HT), but not noradrenaline or dopamine, increased ERK activation and GDNF release via 5-HT2A receptors, ketanserin, a 5-HT2A receptor antagonist, did not have any effect on the amitriptyline-induced ERK activation. Thus, GDNF production by amitriptyline was independent of monoamine. Both of the amitriptyline-induced ERK activation and GDNF mRNA expression were blocked by genistein, a general protein tyrosine kinase (PTK) inhibitor. Actually, we found that amitriptyline acutely increased phosphorylation levels of several phosphotyrosine-containing proteins. Taken together, these findings indicate that ERK activation through PTK regulates antidepressant-induced GDNF production and that the GDNF production in glial cells may be a novel action of the antidepressant, which is independent of monoamine. PMID:17210798

  10. Effects of Surfactants and Microwave-assisted Pretreatment of Orange Peel on Extracellular Enzymes Production by Aspergillus japonicus PJ01.

    PubMed

    Li, Pei-jun; Xia, Jin-lan; Shan, Yang; Nie, Zhen-yuan; Wang, Fei-ran

    2015-06-01

    The effects of surfactants and microwave pretreatment of orange peel powder (OPP) on the production of pectinase, cellulase, and xylanase by Aspergillus japonicus PJ01 in submerged fermentation were investigated. The results showed that when OPP was pretreated only by microwave (630 W, 9 min, and liquid/solid ratio 5), the activities of exo-pectinase, carboxymethyl cellulase (CMCase), xylanase, and filter paper cellulase (FPase) were increased by 11.8, 20.6, 16.2, and 24.0 %, respectively, and when OPP was pretreated by microwave at the same conditions cited above plus PEG 4000 at the concentration of 3 g/L, the activities of the above four enzymes were enhanced by 40.2, 30.3, 40.4, and 40.0 % after 84-h cultivation, respectively. It is suggested a synergistic effect between microwave and surfactant treatment in enhancing the multiextracellular enzymes production by OPP fermentation of A. japonicus PJ01. Chemical composition and Fourier transform infrared spectroscopy (FTIR) analysis displayed that the microwave pretreatment of OPP led to the decrease of hemicellulose and essential oil contents. Scanning electron microscope (SEM) showed that OPP surface after microwave pretreatment became porous and more susceptible to be invaded by A. japonicus. The results demonstrated that pretreatment of OPP by surfactant PEG 4000 and microwave irradiation as environment-friendly way was cost-effective in enhancing the multienzyme production from agricultural waste orange peel.

  11. Production and characterization of a novel extracellular metalloproteinase by a newly isolated moderate halophile, Halobacillus sp. LY6.

    PubMed

    Xin, Li; Hui-Ying, Yu; Xiao-Xue, Liu; Xiao, Sun

    2011-07-01

    A moderately halophilic bacterium LY6 with high proteolytic activity was isolated. Biochemical and physiological characterization, along with 16S rDNA sequence analysis placed the isolate in the genus Halobacillus. The salinity of the culture medium strongly influenced the proteinase production of LY6. Maximum enzyme production was observed in the medium containing 5% Na(2)SO(4) or 10% NaCl. Proteinase production was synchronized with bacterial growth and reached a maximum level during the mid-stationary phase. Enzyme purification was carried out by a simple approach including a combination of ammonium sulfate precipitation and Sephacryl S-100 gel filtration chromatography. SDS-PAGE and gelatin zymography analysis revealed it was a monomer with high molecular weight of 69 kDa. Optimal proteinase activity was obtained at pH 10.0, 40°C, and 10% NaCl. It was high active over broad temperature (30-80°C), pH (6.0-12.0), and NaCl concentration (0-25%) ranges, indicating its thermostable, alkali-stable, and halotolerant nature. Moreover, the enzyme activity was markedly enhanced by Ca(2+) and Cu(2+), but strongly inhibited by EDTA, PAO, and DEPC, indicating that it probably was a metalloproteinase with cysteine and histidine residues located in its active site.

  12. Effects of Surfactants and Microwave-assisted Pretreatment of Orange Peel on Extracellular Enzymes Production by Aspergillus japonicus PJ01.

    PubMed

    Li, Pei-jun; Xia, Jin-lan; Shan, Yang; Nie, Zhen-yuan; Wang, Fei-ran

    2015-06-01

    The effects of surfactants and microwave pretreatment of orange peel powder (OPP) on the production of pectinase, cellulase, and xylanase by Aspergillus japonicus PJ01 in submerged fermentation were investigated. The results showed that when OPP was pretreated only by microwave (630 W, 9 min, and liquid/solid ratio 5), the activities of exo-pectinase, carboxymethyl cellulase (CMCase), xylanase, and filter paper cellulase (FPase) were increased by 11.8, 20.6, 16.2, and 24.0 %, respectively, and when OPP was pretreated by microwave at the same conditions cited above plus PEG 4000 at the concentration of 3 g/L, the activities of the above four enzymes were enhanced by 40.2, 30.3, 40.4, and 40.0 % after 84-h cultivation, respectively. It is suggested a synergistic effect between microwave and surfactant treatment in enhancing the multiextracellular enzymes production by OPP fermentation of A. japonicus PJ01. Chemical composition and Fourier transform infrared spectroscopy (FTIR) analysis displayed that the microwave pretreatment of OPP led to the decrease of hemicellulose and essential oil contents. Scanning electron microscope (SEM) showed that OPP surface after microwave pretreatment became porous and more susceptible to be invaded by A. japonicus. The results demonstrated that pretreatment of OPP by surfactant PEG 4000 and microwave irradiation as environment-friendly way was cost-effective in enhancing the multienzyme production from agricultural waste orange peel. PMID:25920331

  13. Effects of ozone and peroxone on algal separation via dispersed air flotation.

    PubMed

    Nguyen, Truc Linh; Lee, D J; Chang, J S; Liu, J C

    2013-05-01

    Effects of pre-oxidation on algal separation by dispersed air flotation were examined. Ozone (O3) and peroxone (O3 and H2O2) could induce cell lysis, release of intracellular organic matter (IOM), and mineralization of organic substances. Separation efficiency of algal cells improved when pre-oxidized. Total of 76.4% algal cells was separated at 40 mg/L of N-cetyl-N-N-N-trimethylammonium bromide (CTAB), while 95% were separated after 30-min ozonation. Pre-oxidation by ozone and peroxone also enhanced flotation separation efficiency of dissolved organic carbon (DOC), polysaccharide, and protein, in which peroxone process exerted more significantly than O3. Two main mechanisms were involved in flotation separation of unoxidized algal suspension, namely hydrophobic cell surface and cell flocculation resulting from CTAB adsorption. However, flocculation by CTAB was hindered for pre-oxidized algal suspensions. It implied that the compositional changes in extracellular organic matter (EOM) by pre-oxidation were more determined for flotation separation of pre-oxidized cells.

  14. Algal Biomass Analysis by Laser-Based Analytical Techniques—A Review

    PubMed Central

    Pořízka, Pavel; Prochazková, Petra; Prochazka, David; Sládková, Lucia; Novotný, Jan; Petrilak, Michal; Brada, Michal; Samek, Ota; Pilát, Zdeněk; Zemánek, Pavel; Adam, Vojtěch; Kizek, René; Novotný, Karel; Kaiser, Jozef

    2014-01-01

    Algal biomass that is represented mainly by commercially grown algal strains has recently found many potential applications in various fields of interest. Its utilization has been found advantageous in the fields of bioremediation, biofuel production and the food industry. This paper reviews recent developments in the analysis of algal biomass with the main focus on the Laser-Induced Breakdown Spectroscopy, Raman spectroscopy, and partly Laser-Ablation Inductively Coupled Plasma techniques. The advantages of the selected laser-based analytical techniques are revealed and their fields of use are discussed in detail. PMID:25251409

  15. Extracellular matrix production by nucleus pulposus and bone marrow stem cells in response to altered oxygen and glucose microenvironments.

    PubMed

    Naqvi, Syeda M; Buckley, Conor T

    2015-12-01

    Bone marrow (BM) stem cells may be an ideal source of cells for intervertebral disc (IVD) regeneration. However, the harsh biochemical microenvironment of the IVD may significantly influence the biological and metabolic vitality of injected stem cells and impair their repair potential. This study investigated the viability and production of key matrix proteins by nucleus pulposus (NP) and BM stem cells cultured in the typical biochemical microenvironment of the IVD consisting of altered oxygen and glucose concentrations. Culture-expanded NP cells and BM stem cells were encapsulated in 1.5% alginate and ionically crosslinked to form cylindrical hydrogel constructs. Hydrogel constructs were maintained under different glucose concentrations (1, 5 and 25 mM) and external oxygen concentrations (5 and 20%). Cell viability was measured using the Live/Dead® assay and the production of sulphated glycosaminoglycans (sGAG), and collagen was quantified biochemically and histologically. For BM stem cells, IVD-like micro-environmental conditions (5 mM glucose and 5% oxygen) increased the accumulation of sGAG and collagen. In contrast, low glucose conditions (1 mM glucose) combined with 5% external oxygen concentration promoted cell death, inhibiting proliferation and the accumulation of sGAG and collagen. NP-encapsulated alginate constructs were relatively insensitive to oxygen concentration or glucose condition in that they accumulated similar amounts of sGAG under all conditions. Under IVD-like microenvironmental conditions, NP cells were found to have a lower glucose consumption rate compared with BM cells and may in fact be more suitable to adapt and sustain the harsh microenvironmental conditions. Considering the highly specialised microenvironment of the central NP, these results indicate that IVD-like concentrations of low glucose and low oxygen are critical and influential for the survival and biological behaviour of stem cells. Such findings may promote and accelerate

  16. Review of Water Consumption and Water Conservation Technologies in the Algal Biofuel Process.

    PubMed

    Tu, Qingshi; Lu, Mingming; Thiansathit, Worrarat; Keener, Tim C

    2016-01-01

    Although water is one of the most critical factors affecting the sustainable development of algal biofuels, it is much less studied as compared to the extensive research on algal biofuel production technologies. This paper provides a review of the recent studies on water consumption of the algae biofuel process and presents the water conservation technologies applicable at different stages of the algal biofuel process. Open ponds tend to have much higher water consumption (216 to 2000 gal/gal) than photobioreactors (25 to 72 gal/gal). Algae growth accounts for the highest water consumption (165 to 2000 gal/gal) in the open pond system. Water consumption during harvesting, oil extraction, and biofuel conversion are much less compared with the growth stage. Potential water conservation opportunities include technology innovations and better management practices at different stages of algal biofuel production.

  17. Review of Water Consumption and Water Conservation Technologies in the Algal Biofuel Process.

    PubMed

    Tu, Qingshi; Lu, Mingming; Thiansathit, Worrarat; Keener, Tim C

    2016-01-01

    Although water is one of the most critical factors affecting the sustainable development of algal biofuels, it is much less studied as compared to the extensive research on algal biofuel production technologies. This paper provides a review of the recent studies on water consumption of the algae biofuel process and presents the water conservation technologies applicable at different stages of the algal biofuel process. Open ponds tend to have much higher water consumption (216 to 2000 gal/gal) than photobioreactors (25 to 72 gal/gal). Algae growth accounts for the highest water consumption (165 to 2000 gal/gal) in the open pond system. Water consumption during harvesting, oil extraction, and biofuel conversion are much less compared with the growth stage. Potential water conservation opportunities include technology innovations and better management practices at different stages of algal biofuel production. PMID:26803023

  18. From benchtop to raceway : spectroscopic signatures of dynamic biological processes in algal communities.

    SciTech Connect

    Trahan, Christine Alexandra; Garcia, Omar Fidel; Martino, Anthony A.; Raymer, Michelle; Collins, Aaron M.; Hanson, David T.; Turner, Tom; Powell, Amy Jo; James, Scott Carlton; Timlin, Jerilyn Ann; Scholle, Steven; Dwyer, Brian P.; Ruffing, Anne; Jones, Howland D. T.; Ricken, James Bryce; Reichardt, Thomas A.

    2010-08-01

    The search is on for new renewable energy and algal-derived biofuel is a critical piece in the multi-faceted renewable energy puzzle. It has 30x more oil than any terrestrial oilseed crop, ideal composition for biodiesel, no competition with food crops, can be grown in waste water, and is cleaner than petroleum based fuels. This project discusses these three goals: (1) Conduct fundamental research into the effects that dynamic biotic and abiotic stressors have on algal growth and lipid production - Genomics/Transcriptomics, Bioanalytical spectroscopy/Chemical imaging; (2) Discover spectral signatures for algal health at the benchtop and greenhouse scale - Remote sensing, Bioanalytical spectroscopy; and (3) Develop computational model for algal growth and productivity at the raceway scale - Computational modeling.

  19. Spatial variation in the effects of grazing on epilithic algal turfs on the Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    Bonaldo, R. M.; Bellwood, D. R.

    2011-06-01

    Of all benthic components on tropical reefs, algal turfs are the most widespread and the main source of primary productivity. We compared the importance of grazing by herbivores on algal turfs on two zones with marked differences in terms of benthic composition, herbivore biomass and grazing pressure, the inner flat and crest, of an inshore reef on the Great Barrier Reef, Australia. A combination of herbivore exclusion cages and transplants of coral rubble covered by algal turfs between reef zones was used to examine changes in algal turfs over a 4-day experimental period. In situ crest turfs had lower algal height, sediment loads and particulate content than reef flat turfs. Caged samples on the crest exhibited an increase in all three variables. In contrast, in situ and caged treatments on the flat presented algal turfs with similar values for the three analysed variables, with high algal height and heavy particulate and sediment loads. In the absence of cages, reef flat turfs transplanted to the crest had decreased algal height, total particulate material and particulate inorganic content, while the opposite was found in crest turf samples transplanted to the flat. Our results highlight the dynamic nature of algal turfs and the clear differences in the relative importance of herbivory in shaping turf length and sediment load between the reef crest and inner flat.

  20. Algal communities attached to free-drifting, Antarctic icebergs

    NASA Astrophysics Data System (ADS)

    Robison, Bruce H.; Vernet, Maria; Smith, Kenneth L., Jr.

    2011-06-01

    Disintegration of the Antarctic Peninsula's eastern ice shelves has increased the population of icebergs traversing the Weddell Sea, but until recently little was known about their ecological impact on the pelagic environment. Here we describe a class of algal communities that occur on the submerged flanks of large, free-drifting, glacially-derived tabular icebergs. We used remotely operated vehicles to examine these icebergs directly for the first time, to survey the algal communities and collect material for shipboard laboratory studies. The communities, principally diatoms, were associated with a characteristic cupped configuration of the ice surface, and they served as feeding sites for aggregations of Antarctic krill. Production rate measurements indicate that these communities are providing a substantial contribution to regional primary production in summer. As the number of icebergs grows, the number of algae communities may also be increasing, along with their cumulative contribution to organic carbon flux.

  1. Export of algal biomass from the melting Arctic sea ice.

    PubMed

    Boetius, Antje; Albrecht, Sebastian; Bakker, Karel; Bienhold, Christina; Felden, Janine; Fernández-Méndez, Mar; Hendricks, Stefan; Katlein, Christian; Lalande, Catherine; Krumpen, Thomas; Nicolaus, Marcel; Peeken, Ilka; Rabe, Benjamin; Rogacheva, Antonina; Rybakova, Elena; Somavilla, Raquel; Wenzhöfer, Frank

    2013-03-22

    In the Arctic, under-ice primary production is limited to summer months and is restricted not only by ice thickness and snow cover but also by the stratification of the water column, which constrains nutrient supply for algal growth. Research Vessel Polarstern visited the ice-covered eastern-central basins between 82° to 89°N and 30° to 130°E in summer 2012, when Arctic sea ice declined to a record minimum. During this cruise, we observed a widespread deposition of ice algal biomass of on average 9 grams of carbon per square meter to the deep-sea floor of the central Arctic basins. Data from this cruise will contribute to assessing the effect of current climate change on Arctic productivity, biodiversity, and ecological function.

  2. Extracellular matrix-derived products modulate endothelial and progenitor cell migration and proliferation in vitro and stimulate regenerative healing in vivo.

    PubMed

    Vorotnikova, Ekaterina; McIntosh, Donna; Dewilde, Abiche; Zhang, Jianping; Reing, Janet E; Zhang, Li; Cordero, Kevin; Bedelbaeva, Khamilia; Gourevitch, Dimitri; Heber-Katz, Ellen; Badylak, Stephen F; Braunhut, Susan J

    2010-10-01

    Most adult mammals heal without restorative replacement of lost tissue and instead form scar tissue at an injury site. One exception is the adult MRL/MpJ mouse that can regenerate ear and cardiac tissue after wounding with little evidence of scar tissue formation. Following production of a MRL mouse ear hole, 2mm in diameter, a structure rapidly forms at the injury site that resembles the amphibian blastema at a limb amputation site during limb regeneration. We have isolated MRL blastemal cells (MRL-B) from this structure and adapted them to culture. We demonstrate by RT-PCR that even after continuous culturing of these cells they maintain expression of several progenitor cell markers, including DLK (Pref-1), and Msx-1. We have isolated the underlying extracellular matrix (ECM) produced by these MRL-B cells using a new non-proteolytic method and studied the biological activities of this cell-free ECM. Multiplex microELISA analysis of MRL-B cell-free ECM vs. cells revealed selective enrichment of growth factors such as bFGF, HGF and KGF in the matrix compartment. The cell-free ECM, degraded by mild enzyme treatment, was active in promoting migration and proliferation of progenitor cells in vitro and accelerating wound closure in a mouse full thickness cutaneous wound assay in vivo. In vivo, a single application of MRL-B cell matrix-derived products to full thickness cutaneous wounds in non-regenerative mice, B6, induced re-growth of pigmented hair, dermis and epidermis at the wound site whereas scar tissue replaced these tissues at wound sites in mice treated with vehicle alone. These studies suggest that matrix-derived products can stimulate regenerative healing and avert scar tissue formation in adult mammals. PMID:20797438

  3. Beneficial Effects of Marine Algal Compounds in Cosmeceuticals

    PubMed Central

    Thomas, Noel Vinay; Kim, Se-Kwon

    2013-01-01

    The name “cosmeceuticals” is derived from “cosmetics and pharmaceuticals”, indicating that a specific product contains active ingredients. Marine algae have gained much importance in cosmeceutical product development due to their rich bioactive compounds. In the present review, marine algal compounds (phlorotannins, sulfated polysaccharides and tyrosinase inhibitors) have been discussed toward cosmeceutical application. In addition, atopic dermatitis and the possible role of matrix metalloproteinase (MMP) in skin-related diseases have been explored extensively for cosmeceutical products. The proper development of marine algae compounds will be helpful in cosmeceutical product development and in the development of the cosmeceutical industry. PMID:23344156

  4. Development of a rotating algal biofilm growth system for attached microalgae growth with in situ biomass harvest.

    PubMed

    Gross, Martin; Henry, Wesley; Michael, Clayton; Wen, Zhiyou

    2013-12-01

    This work aimed to develop a rotating algal biofilm (RAB) cultivation system that can be widely adopted by microalgae producers for easy biomass harvest. Algal cells were grown on the surface of a material rotating between nutrient-rich liquid and CO2-rich gaseous phase. Scrapping biomass from the attached surface avoided the expensive harvest operations such as centrifugation. Among various attachment materials, cotton sheet resulted in best algal growth, durability, and cost effectiveness. A lab-scale RAB system was further optimized with harvest frequency, rotation speed, and CO2 levels. The algal biomass from the RAB system had a similar water content as that in centrifuged biomass. An open pond raceway retrofitted with a pilot-scale RAB system resulted in a much higher biomass productivity when compared to a control open pond. Collectively, the research shows that the RAB system is an efficient algal culture system for easy biomass harvest with enhanced biomass productivity.

  5. Virulence testing and extracellular subtilisin-like (Pr1) and trypsin-like (Pr2) activity during propagule production of Paecilomyces fumosoroseus isolates from whiteflies (Homoptera: Aleyrodidae).

    PubMed

    Castellanos-Moguel, Judith; González-Barajas, Margarita; Mier, Teresa; Reyes-Montes, María Del Rocío; Aranda, Eduardo; Toriello, Conchita

    2007-03-01

    To properly characterize several isolates of Paecilomyces fumosoroseus, a fungal entomopathogen of whiteflies (Homoptera: Aleyrodidae) and other insect pests for biocontrol purposes, virulence towards Trialeurodes vaporariorum, and subtilisin-like (Pr1) and trypsin-like (Pr2) protease activity during propagule production were investigated in monospore cultures (MCs). The virulence of three MCs towards second instar whiteflies was measured and expressed as lethal median concentration (LC50). Number and widthlength ratio of propagules (blastospores, hyphal bodies, short hyphae, submerged conidia) and extracellular proteolytic activity was determined simultaneously in liquid medium. Total protease activity was assayed with azocasein, Pr1 and Pr2 activity was determined with the substrates N-Succinyl-Ala-Ala-Pro-Phe-p-nitroanilide and N-Benzoyl-Phe-Val-Arg-pnitroanilide, respectively. Natural variability in virulence, propagule production and cuticle-degrading proteases among isolates was observed. Bioassays showed a LC50 of 1.1 x 1,000, 2.5 x 10,000 and 7.6 x 10,000 conidia/ml for MCs EH-506/3, EH-503/3 and EH-520/3, respectively, EH-506/3 being the most virulent isolate. Isolate EH-503/3 produced the highest yield of propagules (7.7 x 10000000 propagules/ml), followed by EH-520/3 with 6.4 x 10000000 and EH-506/3 with 1.0 x 10000000 propagules/ml. Subtilisin-like (Pr1) and trypsin-like (Pr2) activity was present in the three MCs. Subtilisin-like (Pr1) activity was highest (745.7 UPr1/ml at 120 h) in the most virulent isolate, EH-506/3, pointing at Pr1 as a phenotypic marker of virulence for P. fumosoroseus. EH-506/3 appears to be a good candidate for whitefly biocontrol due to its high virulence, Pr1 concentration and rapid transition to blastospores in submerged liquid medium.

  6. Production and Characterization of the Intra- and Extracellular Carbohydrates and Polymeric Substances (EPS) of Three Sea-Ice Diatom Species, and Evidence for a Cryoprotective Role for EPS.

    PubMed

    Aslam, Shazia N; Cresswell-Maynard, Tania; Thomas, David N; Underwood, Graham J C

    2012-12-01

    Diatoms and their associated extracellular polymeric substances (EPS) are major constituents of the microalgal assemblages present within sea ice. Yields and chemical composition of soluble and cell-associated polysaccharides produced by three sea-ice diatoms, Synedropsis sp., Fragilariopsis curta, and F. cylindrus, were compared. Colloidal carbohydrates (CC) contained heteropolysaccharides rich in mannose, xylose, galactose, and glucose. Synedropsis sp. CC consisted mainly of carbohydrates <8 kDa size, with relatively soluble EPS, compared to high proportions of less-soluble EPS produced by both Fragilariopsis spp. F. curta colloidal EPS contained high concentrations of amino sugars (AS). Both Fragilariopsis species had high yields of hot bicarbonate (HB) soluble EPS, rich in xylose, mannose, galactose, and fucose (and AS in F. cylindrus). All species had frustule-associated EPS rich in glucose-mannose. Nutrient limitation resulted in declines in EPS yields and in glucose content of all EPS fractions. Significant similarities between EPS fractions from cultures and different components of natural EPS from Antarctic sea ice were found. Increased salinity (52) reduced growth, but increased yields of EPS in Fragilariopsis cylindrus. Ice formation was inhibited byF. cylindrus, EPS, and by enhanced EPS content (additional xanthan gum) down to -12°C, with growth rate reduced in the presence of xanthan. Differences in the production and composition of EPS between Synedropsis sp. and Fragilariopsis spp., and the association between EPS, freezing and cell survival, supports the hypothesis that EPS production is a strategy to assist polar ice diatoms to survive the cold and saline conditions present in sea ice. PMID:27009999

  7. Fatty acid and stable isotope characteristics of sea ice and pelagic particulate organic matter in the Bering Sea: tools for estimating sea ice algal contribution to Arctic food web production.

    PubMed

    Wang, Shiway W; Budge, Suzanne M; Gradinger, Rolf R; Iken, Katrin; Wooller, Matthew J

    2014-03-01

    We determined fatty acid (FA) profiles and carbon stable isotopic composition of individual FAs (δ(13)CFA values) from sea ice particulate organic matter (i-POM) and pelagic POM (p-POM) in the Bering Sea during maximum ice extent, ice melt, and ice-free conditions in 2010. Based on FA biomarkers, differences in relative composition of diatoms, dinoflagellates, and bacteria were inferred for i-POM versus p-POM and for seasonal succession stages in p-POM. Proportions of diatom markers were higher in i-POM (16:4n-1, 6.6-8.7%; 20:5n-3, 19.6-25.9%) than in p-POM (16:4n-1, 1.2-4.0%; 20:5n-3, 5.5-14.0%). The dinoflagellate marker 22:6n-3/20:5n-3 was highest in p-POM. Bacterial FA concentration was higher in the bottom 1 cm of sea ice (14-245 μg L(-1)) than in the water column (0.6-1.7 μg L(-1)). Many i-POM δ(13)C(FA) values were higher (up to ~10‰) than those of p-POM, and i-POM δ(13)C(FA) values increased with day length. The higher i-POM δ(13)C(FA) values are most likely related to the reduced dissolved inorganic carbon (DIC) availability within the semi-closed sea ice brine channel system. Based on a modified Rayleigh equation, the fraction of sea ice DIC fixed in i-POM ranged from 12 to 73%, implying that carbon was not limiting for primary productivity in the sympagic habitat. These differences in FA composition and δ(13)C(FA) values between i-POM and p-POM will aid efforts to track the proportional contribution of sea ice algal carbon to higher trophic levels in the Bering Sea and likely other Arctic seas.

  8. Didymosphenia geminata: Algal blooms in oligotrophic streams and rivers

    NASA Astrophysics Data System (ADS)

    Sundareshwar, P. V.; Upadhayay, S.; Abessa, M.; Honomichl, S.; Berdanier, B.; Spaulding, S. A.; Sandvik, C.; Trennepohl, A.

    2011-05-01

    In recent decades, the diatom Didymosphenia geminata has emerged as nuisance species in river systems around the world. This periphytic alga forms large “blooms” in temperate streams, presenting a counterintuitive result: the blooms occur primarily in oligotrophic streams and rivers, where phosphorus (P) availability typically limits primary production. The goal of this study is to examine how high algal biomass is formed under low P conditions. We reveal a biogeochemical process by which D. geminata mats concentrate P from flowing waters. First, the mucopolysaccaride stalks of D. geminata adsorb both iron (Fe) and P. Second, enzymatic and bacterial processes interact with Fe to increase the biological availability of P. We propose that a positive feedback between total stalk biomass and high growth rate is created, which results in abundant P for cell division. The affinity of stalks for Fe in association with iron-phosphorus biogeochemistry suggest a resolution to the paradox of algal blooms in oliogotrophic streams and rivers.

  9. Determination of the cyanobacterial toxin cylindrospermopsin in algal food supplements

    PubMed Central

    Liu, H.; Scott, P.M.

    2011-01-01

    For the analysis of blue–green algal food supplements for cylindrospermopsin (CYN), a C18 solid-phase extraction column and a polygraphitized carbon solid-phase extraction column in series was an effective procedure for the clean-up of extracts. Determination of CYN was by liquid chromatography with ultraviolet light detection. At extract spiking levels of CYN equivalent to 25–500 μg g−1, blue–green algal supplement recoveries were in the range 70–90%. CYN was not detected in ten samples of food supplements and one chocolate product, all containing blue–green algae. The limit of detection for the method was 16 μg g−1, and the limit of quantification was 52 μg g−1. PMID:21623503

  10. The engine of the reef: photobiology of the coral-algal symbiosis.

    PubMed

    Roth, Melissa S

    2014-01-01

    Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology, and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs, Symbiodinium must safely harvest sunlight for photosynthesis and dissipate excess energy to prevent oxidative stress. Oxidative stress is caused by environmental stressors such as those associated with global climate change, and ultimately leads to breakdown of the coral-algal symbiosis known as coral bleaching. Recently, large-scale coral bleaching events have become pervasive and frequent threatening and endangering coral reefs. Because the coral-algal symbiosis is the biological engine producing the reef, the future of coral reef ecosystems depends on the ecophysiology of the symbiosis. This review examines the photobiology of the coral-algal symbiosis with particular focus on the photophysiological responses and timescales of corals and Symbiodinium. Additionally, this review summarizes the light environment and its dynamics, the vulnerability of the symbiosis to oxidative stress, the abiotic and biotic factors influencing photosynthesis, the diversity of the coral-algal symbiosis, and recent advances in the field. Studies integrating physiology with the developing "omics" fields will provide new insights into the coral-algal symbiosis. Greater physiological and ecological understanding of the coral-algal symbiosis is needed for protection and conservation of coral reefs.

  11. Algal pigments in Southern Ocean abyssal foraminiferans indicate pelagobenthic coupling

    NASA Astrophysics Data System (ADS)

    Cedhagen, Tomas; Cheah, Wee; Bracher, Astrid; Lejzerowicz, Franck

    2014-10-01

    The cytoplasm of four species of abyssal benthic foraminiferans from the Southern Ocean (around 51°S; 12°W and 50°S; 39°W) was analysed by High Performance Liquid Chromatography (HPLC) and found to contain large concentrations of algal pigments and their degradation products. The composition of the algal pigments in the foraminiferan cytoplasm reflected the plankton community at the surface. Some foraminiferans contained high ratios of chlorophyll a/degraded pigments because they were feeding on fresher phytodetritus. Other foraminiferans contained only degraded pigments which shows that they utilized degraded phytodetritus. The concentration of algal pigment and corresponding degradation products in the foraminiferan cytoplasm is much higher than in the surrounding sediment. It shows that the foraminiferans collect a diluted and sparse food resource and concentrate it as they build up their cytoplasm. This ability contributes to the understanding of the great quantitative success of foraminiferans in the deep sea. Benthic foraminiferans are a food source for many abyssal metazoans. They form a link between the degraded food resources, phytodetritus, back to the active metazoan food chains.

  12. Remote Sensing Marine Ecology: Wind-driven algal blooms in the open oceans and their ecological impacts

    NASA Astrophysics Data System (ADS)

    Tang, DanLing

    2016-07-01

    Algal bloom not only can increase the primary production but also could result in negative ecological consequence, e.g., Harmful Algal Blooms (HABs). According to the classic theory for the formation of algal blooms "critical depth" and "eutrophication", oligotrophic sea area is usually difficult to form a large area of algal blooms, and actually the traditional observation is only sporadic capture to the existence of algal blooms. Taking full advantage of multiple data of satellite remote sensing, this study: 1), introduces "Wind-driven algal blooms in open oceans: observation and mechanisms" It explained except classic coastal Ekman transport, the wind through a variety of mechanisms affecting the formation of algal blooms. Proposed a conceptual model of "Strong wind -upwelling-nutrient-phytoplankton blooms" in Western South China Sea (SCS) to assess role of wind-induced advection transport in phytoplankton bloom formation. It illustrates the nutrient resources that support long-term offshore phytoplankton blooms in the western SCS; 2), Proposal of the theory that "typhoons cause vertical mixing, induce phytoplankton blooms", and quantify their important contribution to marine primary production; Proposal a new ecological index for typhoon. Proposed remote sensing inversion models. 3), Finding of the spatial and temporaldistributions pattern of harmful algal bloom (HAB)and species variations of HAB in the South Yellow Sea and East China Sea, and in the Pearl River estuary, and their oceanic dynamic mechanisms related with monsoon; The project developed new techniques and generated new knowledge, which significantly improved understanding of the formation mechanisms of algal blooms. 1), It proposed "wind-pump" mechanism integrates theoretical system combing "ocean dynamics, development of algal blooms, and impact on primary production", which will benefit fisheries management. 2), A new interdisciplinary subject "Remote Sensing Marine Ecology"(RSME) has been

  13. Rosuvastatin Attenuates CD40L-Induced Downregulation of Extracellular Matrix Production in Human Aortic Smooth Muscle Cells via TRAF6-JNK-NF-κB Pathway

    PubMed Central

    Wang, Xiao-Lin; Zhou, Yuan-Li; Sun, Wei; Li, Li

    2016-01-01

    CD40L and statins exhibit pro-inflammatory and anti-inflammatory effects, respectively. They are both pleiotropic and can regulate extracellular matrix (ECM) degeneration in an atherosclerotic plaque. Statins can decrease both the CD40 expression and the resulting inflammation. However, the effects of CD40L and stains on atherosclerotic plaque ECM production and the underlying mechanisms are not well established. Moreover, prolyl-4-hydroxylase α1 (P4Hα1) is involved in collagen synthesis but its correlations with CD40L and statins are unknown. In the present study, CD40L suppressed P4Hα1 expression in human aortic smooth muscle cells (HASMCs) in a dose- and time-dependent manner, with insignificant changes in MMP2 expression and negative enzymatic activity of MMP9. CD40L increased TRAF6 expression, JNK phosphorylation, NF-κB nuclear translocation as well as DNA binding. Furthermore, silencing TRAF6, JNK or NF-κB genes abolished CD40L-induced suppression of P4Hα1. Lower NF-κB nuclear import rates were observed when JNK or TRAF6 silenced HASMCs were stimulated with CD40L compared to HASMCs with active JNK or TRAF6. Together, these results indicate that CD40L suppresses P4Hα1 expression in HASMCs by activating the TRAF6-JNK- NF-κB pathway. We also found that rosuvastatin inhibits CD40L-induced activation of the TRAF6-JNK- NF-κB pathway, thereby significantly rescuing the CD40L stimulated P4Hα1 inhibition. The results from this study will help find potential targets for stabilizing vulnerable atherosclerotic plaques. PMID:27120457

  14. Production of extracellular polymeric substances (EPS) by Serratia sp.1 using wastewater sludge as raw material and flocculation activity of the EPS produced.

    PubMed

    Bezawada, J; Hoang, N V; More, T T; Yan, S; Tyagi, N; Tyagi, R D; Surampalli, R Y

    2013-10-15

    Growth profile and extracellular polymeric substances (EPS) production of Serratia sp.1 was studied in shake flask fermentation for 72 h using wastewater sludge as raw material. Maximum cell concentration of 6.7 × 10(9) cfu/mL was obtained at 48 h fermentation time. EPS dry weight, flocculation activity and dewaterability of different EPS (tightly bound or TB-EPS, loosely bound or LB-EPS and broth-EPS or B-EPS) were also measured. The highest concentration of LB-EPS (2.45 g/L) and TB-EPS (0.99 g/L) were attained at 48 h of fermentation. Maximum flocculation activity and dewaterability (ΔCST) of TB-EPS (76.4%, 14.5s and 76.5%, 15.5s), LB-EPS (67.8%, 8.1s and 64.7%, 7.6s) and broth EPS (61%, 6.1s and 70.4%, 6.8s) were obtained at 36 and 48 h of growth. Higher flocculation activity and dewaterability were achieved with TB-EPS than with the two other EPS. Characterization of TB-EPS and LB-EPS was done in terms of their protein and carbohydrate content. Protein content was much higher in TB-EPS where as carbohydrate content was only slightly higher in TB-EPS than LB-EPS. Morphology of the Serratia strain after fermentation in sludge and TSB was observed under a scanning electron microscope and the cell size was found to be bigger in the sludge medium than the TSB medium.

  15. Stem Cell-Derived, microRNA-Carrying Extracellular Vesicles: A Novel Approach to Interfering with Mesangial Cell Collagen Production in a Hyperglycaemic Setting

    PubMed Central

    Lombardo, Giusy; Rossetti, Alberto; Rosso, Arturo; Dentelli, Patrizia; Togliatto, Gabriele; Deregibus, Maria Chiara; Taverna, Daniela; Camussi, Giovanni; Brizzi, Maria Felice

    2016-01-01

    Extracellular vesicles (EVs) that are derived from stem cells are proving to be promising therapeutic options. We herein investigate the therapeutic potential of EVs that have been derived from different stem cell sources, bone-marrow (MSC) and human liver (HLSC), on mesangial cells (MCs) exposed to hyperglycaemia. By expressing a dominant negative STAT5 construct (ΔNSTAT5) in HG-cultured MCs, we have demonstrated that miR-21 expression is under the control of STAT5, which translates into Transforming Growth Factor beta (TGFβ) expression and collagen production. A number of approaches have been used to show that both MSC- and HLSC-derived EVs protect MCs from HG-induced damage via the transfer of miR-222. This resulted in STAT5 down-regulation and a decrease in miR-21 content, TGFβ expression and matrix protein synthesis within MCs. Moreover, we demonstrate that changes in the balance between miR-21 and miR-100 in the recipient cell, which are caused by the transfer of EV cargo, further contribute to providing beneficial effects. Interestingly, these effects were only detected in HG-cultured cells. Finally, it was found that HG reduced the expression of the nuclear encoded mitochondrial electron transport chain (ETC) components, CoxIV. It is worth noting that EV administration can rescue CoxIV expression in HG-cultured MCs. These results thus demonstrate that both MSC- and HLSC-derived EVs transfer the machinery needed to preserve MCs from HG-mediated damage. This occurs via the horizontal transfer of functional miR-222 which directly interferes with damaging cues. Moreover, our data indicate that the release of EV cargo into recipient cells provides additional therapeutic advantages against harmful mitochondrial signals. PMID:27611075

  16. Stem Cell-Derived, microRNA-Carrying Extracellular Vesicles: A Novel Approach to Interfering with Mesangial Cell Collagen Production in a Hyperglycaemic Setting.

    PubMed

    Gallo, Sara; Gili, Maddalena; Lombardo, Giusy; Rossetti, Alberto; Rosso, Arturo; Dentelli, Patrizia; Togliatto, Gabriele; Deregibus, Maria Chiara; Taverna, Daniela; Camussi, Giovanni; Brizzi, Maria Felice

    2016-01-01

    Extracellular vesicles (EVs) that are derived from stem cells are proving to be promising therapeutic options. We herein investigate the therapeutic potential of EVs that have been derived from different stem cell sources, bone-marrow (MSC) and human liver (HLSC), on mesangial cells (MCs) exposed to hyperglycaemia. By expressing a dominant negative STAT5 construct (ΔNSTAT5) in HG-cultured MCs, we have demonstrated that miR-21 expression is under the control of STAT5, which translates into Transforming Growth Factor beta (TGFβ) expression and collagen production. A number of approaches have been used to show that both MSC- and HLSC-derived EVs protect MCs from HG-induced damage via the transfer of miR-222. This resulted in STAT5 down-regulation and a decrease in miR-21 content, TGFβ expression and matrix protein synthesis within MCs. Moreover, we demonstrate that changes in the balance between miR-21 and miR-100 in the recipient cell, which are caused by the transfer of EV cargo, further contribute to providing beneficial effects. Interestingly, these effects were only detected in HG-cultured cells. Finally, it was found that HG reduced the expression of the nuclear encoded mitochondrial electron transport chain (ETC) components, CoxIV. It is worth noting that EV administration can rescue CoxIV expression in HG-cultured MCs. These results thus demonstrate that both MSC- and HLSC-derived EVs transfer the machinery needed to preserve MCs from HG-mediated damage. This occurs via the horizontal transfer of functional miR-222 which directly interferes with damaging cues. Moreover, our data indicate that the release of EV cargo into recipient cells provides additional therapeutic advantages against harmful mitochondrial signals. PMID:27611075

  17. Assessment of Algal Farm Designs using a Dynamic Modular Approach

    SciTech Connect

    Abodeely, Jared M.; Stevens, Daniel M.; Ray, Allison E.; Newby, Deborah T.; Coleman, Andre M.; Cafferty, Kara G.

    2014-07-01

    The notion of renewable energy provides an importantmechanism for diversifying an energy portfolio,which ultimately would have numerous benefits including increased energy resilience, reduced reliance on foreign energysupplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth,and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associatedwith algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the development and application of the Algae Logistics Model (ALM) which is tailored to help address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments ofmultiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tierwere sub-selected and assessed using daily site-specific algaebiomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary

  18. Assessment of Algal Farm Designs Using a Dynamic Modular Approach

    SciTech Connect

    Abodeely, Jared; Coleman, Andre M.; Stevens, Daniel M.; Ray, Allison E.; Cafferty, Kara G.; Newby, Deborah T.

    2014-07-01

    The notion of renewable energy provides an important mechanism for diversifying an energy portfolio, which ultimately would have numerous benefits including increased energy resilience, reduction of foreign energy supplies, reduced GHG emissions, development of a green energy sector that contributes to economic growth, and providing a sustainable energy supply. The conversion of autotrophic algae to liquid transportation fuels is the basis of several decades of research to competitively bring energy-scale production into reality; however, many challenges still remain for making algal biofuels economically viable. Addressing current challenges associated with algal production systems, in part, requires the ability to assess spatial and temporal variability, rapidly evaluate alternative algal production system designs, and perform large-scale assessments considering multiple scenarios for thousands of potential sites. We introduce the Algae Logistics Model (ALM) which helps to address these challenges. The flexible nature of the ALM architecture allows the model to: 1) interface with external biomass production and resource assessment models, as well as other relevant datasets including those with spatiotemporal granularity; 2) interchange design processes to enable operational and economic assessments of multiple design configurations, including the integration of current and new innovative technologies; and 3) conduct trade-off analysis to help understand the site-specific techno-economic trade-offs and inform technology decisions. This study uses the ALM to investigate a baseline open-pond production system determined by model harmonization efforts conducted by the U.S. Department of Energy. Six sites in the U.S. southern-tier were sub-selected and assessed using daily site-specific algae biomass productivity data to determine the economic viability of large-scale open-pond systems. Results show that costs can vary significantly depending on location and biomass

  19. Effect of nitrogen/phosphorus concentration on algal organic matter generation of the diatom Nitzschia palea: Total indicators and spectroscopic characterization.

    PubMed

    Han, Linlin; Xu, Bingbing; Qi, Fei; Chen, Zhonglin

    2016-09-01

    Critical algal blooms in great lakes increase the level of algal organic matters (AOMs), significantly altering the composition of natural organic matters (NOMs) in freshwater of lake. This study examined the AOM's characteristics of Nitzschia palea (N. palea), one kind of the predominant diatom and an important biomarker of water quality in the great lakes of China, to investigate the effect of AOMs on the variation of NOMs in lakes and the process of algal energy. Excitation-emission matrix fluorescence (EEM) spectroscopy, synchronous fluorescence (SF) spectroscopy and deconvolution UV-vis (D-UV) spectroscopy were utilized to characterize AOMs to study the effects of nutrient loading on the composition change of AOMs. From results, it was revealed that the phosphorus is the limiting factor for N. palea's growth and the generation of both total organic carbon and amino acids but the nitrogen is more important for the generation of carbohydrates and proteins. EEM spectra revealed differences in the composition of extracellular organic matter and intracellular organic matter. Regardless of the nitrogen and phosphorus concentrations, aromatic proteins and soluble microbial products were the main components, but the nitrogen concentration had a significant impact on their composition. The SF spectra were used to study the AOMs for the first time and identified that the protein-like substances were the major component of AOMs, creating as a result of aromatic group condensation. The D-UV spectra showed carboxylic acid and esters were the main functional groups in the EOMs, with -OCH3, -SO2NH2, -CN, -NH2, -O- and -COCH3 functional groups substituting into benzene rings. PMID:27593280

  20. Eukaryotic algal phytochromes span the visible spectrum.

    PubMed

    Rockwell, Nathan C; Duanmu, Deqiang; Martin, Shelley S; Bachy, Charles; Price, Dana C; Bhattacharya, Debashish; Worden, Alexandra Z; Lagarias, J Clark

    2014-03-11

    Plant phytochromes are photoswitchable red/far-red photoreceptors that allow competition with neighboring plants for photosynthetically active red light. In aquatic environments, red and far-red light are rapidly attenuated with depth; therefore, photosynthetic species must use shorter wavelengths of light. Nevertheless, phytochrome-related proteins are found in recently sequenced genomes of many eukaryotic algae from aquatic environments. We examined the photosensory properties of seven phytochromes from diverse algae: four prasinophyte (green algal) species, the heterokont (brown algal) Ectocarpus siliculosus, and two glaucophyte species. We demonstrate that algal phytochromes are not limited to red and far-red responses. Instead, different algal phytochromes can sense orange, green, and even blue light. Characterization of these previously undescribed photosensors using CD spectroscopy supports a structurally heterogeneous chromophore in the far-red-absorbing photostate. Our study thus demonstrates that extensive spectral tuning of phytochromes has evolved in phylogenetically distinct lineages of aquatic photosynthetic eukaryotes.

  1. High Frequency Monitoring for Harmful Algal Blooms

    EPA Science Inventory

    Harmful algal blooms (HABs) are increasingly becoming a significant ecologic, economic, and social driver in the use of water resources. Cyanobacteria and their toxins play an important role in management decisions for drinking water utilities and public health officials. Online ...

  2. Direct conversion of algal biomass to biofuel

    DOEpatents

    Deng, Shuguang; Patil, Prafulla D; Gude, Veera Gnaneswar

    2014-10-14

    A method and system for providing direct conversion of algal biomass. Optionally, the method and system can be used to directly convert dry algal biomass to biodiesels under microwave irradiation by combining the reaction and combining steps. Alternatively, wet algae can be directly processed and converted to fatty acid methyl esters, which have the major components of biodiesels, by reacting with methanol at predetermined pressure and temperature ranges.

  3. Comparative analysis of two classes of quorum-sensing signaling systems that control production of extracellular proteins and secondary metabolites in Erwinia carotovora subspecies.

    PubMed

    Chatterjee, Asita; Cui, Yaya; Hasegawa, Hiroaki; Leigh, Nathan; Dixit, Vaishali; Chatterjee, Arun K

    2005-12-01

    In Erwinia carotovora subspecies, N-acyl homoserine lactone (AHL) controls the expression of various traits, including extracellular enzyme/protein production and pathogenicity. We report here that E. carotovora subspecies possess two classes of quorum-sensing signaling systems defined by the nature of the major AHL analog produced as well as structural and functional characteristics of AHL synthase (AhlI) and AHL receptor (ExpR). Class I strains represented by E. carotovora subsp. atroseptica strain Eca12 and E. carotovora subsp. carotovora strains EC153 and SCC3193 produce 3-oxo-C8-HL (N-3-oxooctanoyl-l-homoserine lactone) as the major AHL analog as well as low but detectable levels of 3-oxo-C6-HL (N-3-oxohexanoyl-l-homoserine lactone). In contrast, the members of class II (i.e., E. carotovora subsp. betavasculorum strain Ecb168 and E. carotovora subsp. carotovora strains Ecc71 and SCRI193) produce 3-oxo-C6-HL as the major analog. ExpR species of both classes activate rsmA (Rsm, repressor of secondary metabolites) transcription and bind rsmA DNA. Gel mobility shift assays with maltose-binding protein (MBP)-ExpR(71) and MBP-ExpR(153) fusion proteins show that both bind a 20-mer sequence present in rsmA. The two ExpR functions (i.e., expR-mediated activation of rsmA expression and ExpR binding with rsmA DNA) are inhibited by AHL. The AHL effects are remarkably specific in that expR effect of EC153, a strain belonging to class I, is counteracted by 3-oxo-C8-HL but not by 3-oxo-C6-HL. Conversely, the expR effect of Ecc71, a strain belonging to class II, is neutralized by 3-oxo-C6-HL but not by 3-oxo-C8-HL. The AHL responses correlated with expR-mediated inhibition of exoprotein and secondary metabolite production.

  4. Algal and fungal diversity in Antarctic lichens.

    PubMed

    Park, Chae Haeng; Kim, Kyung Mo; Elvebakk, Arve; Kim, Ok-Sun; Jeong, Gajin; Hong, Soon Gyu

    2015-01-01

    The composition of lichen ecosystems except mycobiont and photobiont has not been evaluated intensively. In addition, recent studies to identify algal genotypes have raised questions about the specific relationship between mycobiont and photobiont. In the current study, we analyzed algal and fungal community structures in lichen species from King George Island, Antarctica, by pyrosequencing of eukaryotic large subunit (LSU) and algal internal transcribed spacer (ITS) domains of the nuclear rRNA gene. The sequencing results of LSU and ITS regions indicated that each lichen thallus contained diverse algal species. The major algal operational taxonomic unit (OTU) defined at a 99% similarity cutoff of LSU sequences accounted for 78.7-100% of the total algal community in each sample. In several cases, the major OTUs defined by LSU sequences were represented by two closely related OTUs defined by 98% sequence similarity of ITS domain. The results of LSU sequences indicated that lichen-associated fungi belonged to the Arthoniomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, and Sordariomycetes of the Ascomycota, and Tremellomycetes and Cystobasidiomycetes of the Basidiomycota. The composition of major photobiont species and lichen-associated fungal community were mostly related to the mycobiont species. The contribution of growth forms or substrates on composition of photobiont and lichen-associated fungi was not evident. PMID:25105247

  5. Algal and fungal diversity in Antarctic lichens.

    PubMed

    Park, Chae Haeng; Kim, Kyung Mo; Elvebakk, Arve; Kim, Ok-Sun; Jeong, Gajin; Hong, Soon Gyu

    2015-01-01

    The composition of lichen ecosystems except mycobiont and photobiont has not been evaluated intensively. In addition, recent studies to identify algal genotypes have raised questions about the specific relationship between mycobiont and photobiont. In the current study, we analyzed algal and fungal community structures in lichen species from King George Island, Antarctica, by pyrosequencing of eukaryotic large subunit (LSU) and algal internal transcribed spacer (ITS) domains of the nuclear rRNA gene. The sequencing results of LSU and ITS regions indicated that each lichen thallus contained diverse algal species. The major algal operational taxonomic unit (OTU) defined at a 99% similarity cutoff of LSU sequences accounted for 78.7-100% of the total algal community in each sample. In several cases, the major OTUs defined by LSU sequences were represented by two closely related OTUs defined by 98% sequence similarity of ITS domain. The results of LSU sequences indicated that lichen-associated fungi belonged to the Arthoniomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, and Sordariomycetes of the Ascomycota, and Tremellomycetes and Cystobasidiomycetes of the Basidiomycota. The composition of major photobiont species and lichen-associated fungal community were mostly related to the mycobiont species. The contribution of growth forms or substrates on composition of photobiont and lichen-associated fungi was not evident.

  6. A Geospatial Analysis of Harmful Algal Blooms along the California Coast

    NASA Astrophysics Data System (ADS)

    Jensen, C.; Rothwell, R.; Johnson, E.; Condamoor, M.; Patil, M.; Largier, J. L.; Schmidt, C.

    2012-12-01

    Algal blooms are natural phenomena consisting of the rapid growth of phytoplankton populations. Some blooms have negative ecological or public health effects due to toxin production and removal of oxygen from the water column. In recent years, such "harmful algal blooms" (HABs) have been linked to human illness, economic loss from decreased fishing, and ecological damage related to marine life mortality as well as eutrophication. A notable HAB event occurred along the coast of northern California in August 2011, resulting in economic and ecological impacts of approximately $82 million. This was one of several algal blooms that occurred in fall 2011, with similar northward propagating algal blooms occurring in autumn of other years. Although the scale of the bloom impact is well-known, the spatial and temporal extent of the bloom boundary is still unclear. This study tracked the space-time pattern of numerous blooms during August-October 2011 using multiple NASA Earth observing systems in an effort to quantify and understand the structure of these recurrent bloom events. Aqua MODIS images were used to quantify surface chlorophyll-α levels, and thus to map the extent and development of all autumn algal blooms. The relation between sea surface temperature, ocean surface topography, and algal blooms was further explored with AVHRR and Jason-2 satellite data. A Generalized Additive Model (GAM) was used to identify the environmental factors most statistically influential in algal blooms and specifically in HAB events. Results from this study will assist California's Departments of Public Health and Fish & Game in mitigating and managing the impact of future harmful algal blooms.

  7. Raman microspectroscopy based sensor of algal lipid unsaturation

    NASA Astrophysics Data System (ADS)

    Samek, Ota; Pilát, Zdeněk; Jonáš, Alexandr; Zemánek, Pavel; Šerý, Mojmír; Ježek, Jan; Bernatová, Silvie; Nedbal, Ladislav; Trtílek, Martin

    2011-05-01

    Raman spectroscopy is a powerful tool for chemical analysis. This technique can elucidate fundamental questions about the metabolic processes and intercellular variability on a single cell level. Therefore, Raman spectroscopy can significantly contribute to the study and use of microalgae in systems biology and biofuel technology. Raman spectroscopy can be combined with optical tweezers. We have employed microfluidic system to deliver the sampled microalgae to the Raman-tweezers. This instrument is able to measure chemical composition of cells and to track metabolic processes in vivo, in real-time and label-free making it possible to detect population variability in a wide array of traits. Moreover, employing an active sorting switch, cells can be separated depending on input parameters obtained from Raman spectra. We focus on algal lipids which are promising potential products for biofuel as well as for nutrition. Important parameter characterizing the algal lipids is the degree of unsaturation of the constituent fatty acids. We demonstrate the capacity of our Raman tweezers based sensor to sort cells according to the degree of unsaturation in lipid storage bodies of individual living algal cells.

  8. Variations of algal communities cause darkening of a Greenland glacier.

    PubMed

    Lutz, Stefanie; Anesio, Alexandre M; Jorge Villar, Susana E; Benning, Liane G

    2014-08-01

    We have assessed the microbial ecology on the surface of Mittivakkat glacier in SE-Greenland during the exceptional high melting season in July 2012 when the so far most extreme melting rate for the Greenland Ice Sheet has been recorded. By employing a complementary and multi-disciplinary field sampling and analytical approach, we quantified the dramatic changes in the different microbial surface habitats (green snow, red snow, biofilms, grey ice, cryoconite holes). The observed clear change in dominant algal community and their rapidly changing cryo-organic adaptation inventory was linked to the high melting rate. The changes in carbon and nutrient fluxes between different microbial pools (from snow to ice, cryoconite holes and glacial forefronts) revealed that snow and ice algae dominate the net primary production at the onset of melting, and that they have the potential to support the cryoconite hole communities as carbon and nutrient sources. A large proportion of algal cells is retained on the glacial surface and temporal and spatial changes in pigmentation contribute to the darkening of the snow and ice surfaces. This implies that the fast, melt-induced algal growth has a high albedo reduction potential, and this may lead to a positive feedback speeding up melting processes.

  9. Micro-structured surfaces for algal biofilm growth

    NASA Astrophysics Data System (ADS)

    Sathananthan, Suthamathy; Genin, Scott N.; Aitchison, J. Stewart; Allen, D. Grant

    2013-12-01

    It is well known that cells respond to structured surface cues that are on the micro/nanometer scale. Tissue engineering and bio-fouling fields have utilized the semiconductor device fabrication processes to make micro- and nanometer patterned surfaces to study animal cell tissue formation and to prevent algae attachment on marine surfaces respectively. In this paper we describe the use of micro-structured surfaces to study the attachment and growth of algal films. This paper gives an overview of how micro-structured surfaces are made for this purpose, how they are incorporated into a photo bioreactor and how this patterning influences the growth of an algal biofilm. Our results suggest that surface patterning with deeper V-groove patterns that are of the same size scale as the algal species has resulted in higher biomass productivity giving them a chance to embed and attach on the slope and flat surfaces whereas shallower size grooves and completely flat surfaces did not show this trend.

  10. Floating Ice-Algal Aggregates below Melting Arctic Sea Ice

    PubMed Central

    Assmy, Philipp; Ehn, Jens K.; Fernández-Méndez, Mar; Hop, Haakon; Katlein, Christian; Sundfjord, Arild; Bluhm, Katrin; Daase, Malin; Engel, Anja; Fransson, Agneta; Granskog, Mats A.; Hudson, Stephen R.; Kristiansen, Svein; Nicolaus, Marcel; Peeken, Ilka; Renner, Angelika H. H.; Spreen, Gunnar; Tatarek, Agnieszka; Wiktor, Jozef

    2013-01-01

    During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layers. We were able, for the first time, to obtain quantitative abundance and biomass estimates of these aggregates. Although their biomass and production on a square metre basis was small compared to ice-algal blooms, the floating ice-algal aggregates supported high levels of biological activity on the scale of the individual aggregate. In addition they constituted a food source for the ice-associated fauna as revealed by pigments indicative of zooplankton grazing, high abundance of naked ciliates, and ice amphipods associated with them. During the Arctic melt season, these floating aggregates likely play an important ecological role in an otherwise impoverished near-surface sea ice environment. Our findings provide important observations and measurements of a unique aggregate-based habitat during the 2012 record sea ice minimum year. PMID:24204642

  11. Floating ice-algal aggregates below melting arctic sea ice.

    PubMed

    Assmy, Philipp; Ehn, Jens K; Fernández-Méndez, Mar; Hop, Haakon; Katlein, Christian; Sundfjord, Arild; Bluhm, Katrin; Daase, Malin; Engel, Anja; Fransson, Agneta; Granskog, Mats A; Hudson, Stephen R; Kristiansen, Svein; Nicolaus, Marcel; Peeken, Ilka; Renner, Angelika H H; Spreen, Gunnar; Tatarek, Agnieszka; Wiktor, Jozef

    2013-01-01

    During two consecutive cruises to the Eastern Central Arctic in late summer 2012, we observed floating algal aggregates in the melt-water layer below and between melting ice floes of first-year pack ice. The macroscopic (1-15 cm in diameter) aggregates had a mucous consistency and were dominated by typical ice-associated pennate diatoms embedded within the mucous matrix. Aggregates maintained buoyancy and accumulated just above a strong pycnocline that separated meltwater and seawater layers. We were able, for the first time, to obtain quantitative abundance and biomass estimates of these aggregates. Although their biomass and production on a square metre basis was small compared to ice-algal blooms, the floating ice-algal aggregates supported high levels of biological activity on the scale of the individual aggregate. In addition they constituted a food source for the ice-associated fauna as revealed by pigments indicative of zooplankton grazing, high abundance of naked ciliates, and ice amphipods associated with them. During the Arctic melt season, these floating aggregates likely play an important ecological role in an otherwise impoverished near-surface sea ice environment. Our findings provide important observations and measurements of a unique aggregate-based habitat during the 2012 record sea ice minimum year.

  12. An algal solution to large scale wastewater amelioration

    SciTech Connect

    Adey, W.H.

    1995-06-01

    Wastewater nutrients can be lowered to oligotrophic levels through uptake by algal biomass, while photosynthetic oxygen removes bacterial BOD, and oxygen-based ions, with UV application, can break down xenobiotic organic compounds. Algae also uptake heavy metals in cell walls, and the high pH from CO{sub 25} removal precipitates metals, earth metals and phosphorus. Algal biomass produced from many wastewaters has valuable commercial applications. Algal Turf Scrubbing (ATS) was developed as a tool to control water quality in ecosystem models, often at oligotrophic levels. ATS has routinely achieved biomass production (and water amelioration capability) of over 50 g (dry mass) m{sup -2} day{sup -1} in secondary sewage. Engineering innovations, with mechanized harvest, have brought ATS to large scale with a pilot sewage plant in central California. This is a low cost, modular unit, at 1000 cubic meters per day, and plans are underway to expand to city capacity for Tertiary-Quinary water recovery. A wide variety of wastewater applications, from agricultural, to aquacultural to industrial will be discussed.

  13. Study of cnidarian-algal symbiosis in the "omics" age.

    PubMed

    Meyer, Eli; Weis, Virginia M

    2012-08-01

    The symbiotic associations between cnidarians and dinoflagellate algae (Symbiodinium) support productive and diverse ecosystems in coral reefs. Many aspects of this association, including the mechanistic basis of host-symbiont recognition and metabolic interaction, remain poorly understood. The first completed genome sequence for a symbiotic anthozoan is now available (the coral Acropora digitifera), and extensive expressed sequence tag resources are available for a variety of other symbiotic corals and anemones. These resources make it possible to profile gene expression, protein abundance, and protein localization associated with the symbiotic state. Here we review the history of "omics" studies of cnidarian-algal symbiosis and the current availability of sequence resources for corals and anemones, identifying genes putatively involved in symbiosis across 10 anthozoan species. The public availability of candidate symbiosis-associated genes leaves the field of cnidarian-algal symbiosis poised for in-depth comparative studies of sequence diversity and gene expression and for targeted functional studies of genes associated with symbiosis. Reviewing the progress to date suggests directions for future investigations of cnidarian-algal symbiosis that include (i) sequencing of Symbiodinium, (ii) proteomic analysis of the symbiosome membrane complex, (iii) glycomic analysis of Symbiodinium cell surfaces, and (iv) expression profiling of the gastrodermal cells hosting Symbiodinium. PMID:22983032

  14. Towards developing algal synthetic biology.

    PubMed

    Scaife, Mark Aden; Smith, Alison Gail

    2016-06-15

    The genetic, physiological and metabolic diversity of microalgae has driven fundamental research into photosynthesis, flagella structure and function, and eukaryotic evolution. Within the last 10 years these organisms have also been investigated as potential biotechnology platforms, for example to produce high value compounds such as long chain polyunsaturated fatty acids, pigments and antioxidants, and for biodiesel precursors, in particular triacylglycerols (TAGs). Transformation protocols, molecular tools and genome sequences are available for a number of model species including the green alga Chlamydomonas reinhardtii and the diatom Phaeodactylum tricornutum, although for both species there are bottlenecks to be overcome to allow rapid and predictable genetic manipulation. One approach to do this would be to apply the principles of synthetic biology to microalgae, namely the cycle of Design-Build-Test, which requires more robust, predictable and high throughput methods. In this mini-review we highlight recent progress in the areas of improving transgene expression, genome editing, identification and design of standard genetic elements (parts), and the use of microfluidics to increase throughput. We suggest that combining these approaches will provide the means to establish algal synthetic biology, and that application of standard parts and workflows will avoid parallel development and capitalize on lessons learned from other systems. PMID:27284033

  15. Microflotation performance for algal separation.

    PubMed

    Hanotu, James; Bandulasena, H C Hemaka; Zimmerman, William B

    2012-07-01

    The performance of microflotation, dispersed air flotation with microbubble clouds with bubble size about 50 µm, for algae separation using fluidic oscillation for microbubble generation is investigated. This fluidic oscillator converts continuous air supply into oscillatory flow with a regular frequency to generate bubbles of the scale of the exit pore. Bubble characterization results showed that average bubble size generated under oscillatory air flow state was 86 µm, approximately twice the size of the diffuser pore size of 38 µm. In contrast, continuous air flow at the same rate through the same diffusers yielded an average bubble size of 1,059 µm, 28 times larger than the pore size. Following microbubble generation, the separation of algal cells under fluidic oscillator generated microbubbles was investigated by varying metallic coagulant types, concentration and pH. Best performances were recorded at the highest coagulant dose (150 mg/L) applied under acidic conditions (pH 5). Amongst the three metallic coagulants studied, ferric chloride yielded the overall best result of 99.2% under the optimum conditions followed closely by ferric sulfate (98.1%) and aluminum sulfate with 95.2%. This compares well with conventional dissolved air flotation (DAF) benchmarks, but has a highly turbulent flow, whereas microflotation is laminar with several orders of magnitude lower energy density.

  16. Towards developing algal synthetic biology.

    PubMed

    Scaife, Mark Aden; Smith, Alison Gail

    2016-06-15

    The genetic, physiological and metabolic diversity of microalgae has driven fundamental research into photosynthesis, flagella structure and function, and eukaryotic evolution. Within the last 10 years these organisms have also been investigated as potential biotechnology platforms, for example to produce high value compounds such as long chain polyunsaturated fatty acids, pigments and antioxidants, and for biodiesel precursors, in particular triacylglycerols (TAGs). Transformation protocols, molecular tools and genome sequences are available for a number of model species including the green alga Chlamydomonas reinhardtii and the diatom Phaeodactylum tricornutum, although for both species there are bottlenecks to be overcome to allow rapid and predictable genetic manipulation. One approach to do this would be to apply the principles of synthetic biology to microalgae, namely the cycle of Design-Build-Test, which requires more robust, predictable and high throughput methods. In this mini-review we highlight recent progress in the areas of improving transgene expression, genome editing, identification and design of standard genetic elements (parts), and the use of microfluidics to increase throughput. We suggest that combining these approaches will provide the means to establish algal synthetic biology, and that application of standard parts and workflows will avoid parallel development and capitalize on lessons learned from other systems.

  17. Microbial dynamics of an epilithic algal-bacterial mat community in an oligotrophic, high alpine stream

    SciTech Connect

    McFeters, G.A.; Haack, T.K.

    1982-04-01

    Previous studies of an epilithic algal-bacterial community in a pristine mountain stream suggested that heterotrophic bacteria were responding to the metabolic activities of the photorophic population. Subsequent studies were performed to follow the flow of labeled carbon, from its initial inorganic form, through the trophic levels of the mat community. A majority of primary production metabolites were excreted by the algal population during active growth; this shifted to an incorporation into cellular material as phototrophic activity declined. Results suggest that there was a direct flux of soluble algal products to the bacterial population, with little heterotrophic utilization of dissolved organics from the overlying stream water. Both phototrophic productivity and bacterial utilization of algal products peaked at approximately the same time of year. Activity of the diatom-dominated algal population declined as silica concentrations in the stream water dropped, leading to a situation in which the sessile bacteria were substrate limited. These events resulted in an almost complete disappearance of the community in early September.

  18. An extracellular material elaborated by Micrococcus sodonensis.

    PubMed

    CAMPBELL, J N; EVANS, J B; PERRY, J J; NIVEN, C F

    1961-12-01

    Campbell, J. N. (American Meat Institute Foundation, Chicago, Ill.), James B. Evans Jerome J. Perry, and C. F. Niven, Jr. An extracellular material elaborated by Micrococcus sodonensis. J. Bacteriol. 82:828-837. 1961.-When actively growing in a yeast extract-tryptone broth, Micrococcus sodonensis produced rather large quantities of an extracellular material. On a dry weight basis, this material consisted of approximately 80% deoxyribonucleic acid (DNA), 6% ribonucleic acid, 13% protein, and a small quantity of a cell pigment which contained an associated i