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Sample records for psychrophilic microorganisms challenges

  1. Cellulases from psychrophilic microorganisms: a review.

    PubMed

    Kasana, Ramesh C; Gulati, Arvind

    2011-12-01

    Cellulases are hydrolytic enzymes that catalyze total hydrolysis of cellulose into sugars. Cellulases are produced by various groups of microorganisms and animals; however, psychrophiles are the ideal candidates for the production of enzymes active at low temperature and stable under alkaline conditions, in the presence of oxidants and detergents, which are in large demand as laundry additives. The cellulases from psychrophiles also find application in environmental bioremediation, food industry and molecular biology. Research work on cellulase has been done over the last six decades, but there is no exclusive review available on the cellulases from psychrophiles. This review is an attempt to fill this gap by providing all the relevant information exclusively for cellulases from psychrophiles, with a focus on the present status of knowledge on their activity, molecular characteristics, gene cloning, statistical experimental designs, crystal structure, and strategies for the improvement of psychrophilic cellulases.

  2. Psychrophiles

    NASA Astrophysics Data System (ADS)

    Siddiqui, Khawar S.; Williams, Timothy J.; Wilkins, David; Yau, Sheree; Allen, Michelle A.; Brown, Mark V.; Lauro, Federico M.; Cavicchioli, Ricardo

    2013-05-01

    Psychrophilic (cold-adapted) microorganisms make a major contribution to Earth's biomass and perform critical roles in global biogeochemical cycles. The vast extent and environmental diversity of Earth's cold biosphere has selected for equally diverse microbial assemblages that can include archaea, bacteria, eucarya, and viruses. Underpinning the important ecological roles of psychrophiles are exquisite mechanisms of physiological adaptation. Evolution has also selected for cold-active traits at the level of molecular adaptation, and enzymes from psychrophiles are characterized by specific structural, functional, and stability properties. These characteristics of enzymes from psychrophiles not only manifest in efficient low-temperature activity, but also result in a flexible protein structure that enables biocatalysis in nonaqueous solvents. In this review, we examine the ecology of Antarctic psychrophiles, physiological adaptation of psychrophiles, and properties of cold-adapted proteins, and we provide a view of how these characteristics inform studies of astrobiology.

  3. Overexpression, purification, and enthalpy of unfolding of ferricytochrome c552 from a psychrophilic microorganism.

    PubMed

    Oswald, Victoria F; Chen, WeiTing; Harvilla, Paul B; Magyar, John S

    2014-02-01

    The psychrophilic, hydrocarbonoclastic microorganism Colwellia psychrerythraea is important in global nutrient cycling and bioremediation. In order to investigate how this organism can live so efficiently at low temperatures (~4°C), thermal denaturation studies of a small electron transfer protein from Colwellia were performed. Colwellia cytochrome c552 was overexpressed in Escherichia coli, isolated, purified, and characterized by UV-visible absorption spectroscopy. The melting temperature (Tm) and the van't Hoff enthalpy (ΔHvH) were determined. These values suggest an unexpectedly high stability for this psychrophilic cytochrome.

  4. [Distribution of psychrophilic microorganisms in terrestrial biotopes of the Antarctic Region].

    PubMed

    Romanovskaia, V A; Tashirev, A B; Shilin, S O; Gladka, G V

    2012-01-01

    It is shown that the total number of chemoorganotrophic aerobic microorganisms in the Antarctic Region revealed at 1 degree C and 5 degrees C made from 10(4) up to 10(6) cells/g of plant-soil sample of biotopes: grass Deschampcia antarctica, grass Colobanthus, green mosses, crustose black lichens and a biofilm of accretion on vertical rocks. From 10(6) up to 10(8) cells/g of samples were revealed in the same Antarctic samples at 30 degrees C. At 42 degrees C thermotolerant bacteria were either absent, or their quantity was less than 10(4) cells/g of samples. Thus the fraction (part) of the Antarctic microorganisms, which grow at different temperatures, varied: at 1-5 degrees C their part made from 5 to 15%, and at 30 degrees C--from 10 to 45%. At 15-20 degrees C the growth of both psychrophilic/psychrotolerant, and mesophilic microorganisms was observed. When comparing the results of plating of samples from different climatic zones (the Antarctic Region and Ukraine), it is shown that in the Antarctic biotopes in comparison with biotopes of the zone with temperate climate: (1) the total number of microorganisms is lower, (2) quantity of psychrophilic/psychrotolerant bacteria is higher, (3) quantity of mesophilic microorganisms is less, (4) as a result the part psychrophilic/psychrotolerant microorganisms in the total number of microorganisms is much higher. It is evident, that low temperatures, and also daily cycles of freezing and thawing are factors which limit microbial colonization ofAntarctic biotopes.

  5. The Characterization of Psychrophilic Microorganisms and their potentially useful Cold-Active Glycosidases Final Progress Report

    SciTech Connect

    Brenchly, Jean E.

    2008-06-30

    Our studies of novel, cold-loving microorganisms have focused on two distinct extreme environments. The first is an ice core sample from a 120,000 year old Greenland glacier. The results of this study are particularly exciting and have been highlighted with press releases and additional coverage. The first press release in 2004 was based on our presentation at the General Meeting of the American Society for Microbiology and was augmented by coverage of our publication (Appl. Environ. Microbiol. 2005. Vol. 71:7806) in the Current Topics section of the ASM news journal, “Microbe.” Of special interest for this report was the isolation of numerous, phylogenetically distinct and potentially novel ultrasmall microorganisms. The detection and isolation of members of the ultrasmall population is significant because these cells pass through 0.2 micron pore filters that are generally used to trap microorganisms from environmental samples. Thus, analyses by other investigators that examined only cells captured on the filters would have missed a significant portion of this population. Only a few ultrasmall isolates had been obtained prior to our examination of the ice core samples. Our development of a filtration enrichment and subsequent cultivation of these organisms has added extensively to the collection of, and knowledge about, this important population in the microbial world.

  6. Biotechnological uses of enzymes from psychrophiles

    PubMed Central

    Cavicchioli, R.; Charlton, T.; Ertan, H.; Omar, S. Mohd; Siddiqui, K. S.; Williams, T. J.

    2011-01-01

    Summary The bulk of the Earth's biosphere is cold (e.g. 90% of the ocean's waters are ≤ 5°C), sustaining a broad diversity of microbial life. The permanently cold environments vary from the deep ocean to alpine reaches and to polar regions. Commensurate with the extent and diversity of the ecosystems that harbour psychrophilic life, the functional capacity of the microorganisms that inhabitat the cold biosphere are equally diverse. As a result, indigenous psychrophilic microorganisms provide an enormous natural resource of enzymes that function effectively in the cold, and these cold‐adapted enzymes have been targeted for their biotechnological potential. In this review we describe the main properties of enzymes from psychrophiles and describe some of their known biotechnological applications and ways to potentially improve their value for biotechnology. The review also covers the use of metagenomics for enzyme screening, the development of psychrophilic gene expression systems and the use of enzymes for cleaning. PMID:21733127

  7. Bioprospection of marine microorganisms: potential and challenges for Argentina.

    PubMed

    Dionisi, Hebe M; Lozada, Mariana; Olivera, Nelda L

    2012-01-01

    The marine environments of Argentina have a remarkable extension, as well as high biological productivity and biodiversity of both macro- and microorganisms. Despite having a great potential for biotechnological applications, the microorganisms inhabiting these ecosystems remain mostly unexplored and unexploited. In this review, we study the research topics and the interactions among Argentinean laboratories, by analyzing current articles published on biotechnology-related marine microbiology by researchers of this country. In addition, we identify the challenges and opportunities for Argentina to take advantage of the genetic potential of its marine microorganisms. Finally, we suggest possible actions that could improve the development of this research field, as well as the utilization of this knowledge to solve societal needs.

  8. Psychrophilic Lipase from Arctic Bacterium

    PubMed Central

    Ramle, Zakiah; Rahim, Rashidah Abdul

    2016-01-01

    A lipase producer psychrophilic microorganism isolated from Arctic sample was studied. The genomic DNA of the isolate was extracted using modified CTAB method. Identification of the isolate by morphological and 16S rRNA sequence analysis revealed that the isolate is closely related to Arthrobacter gangotriensis (97% similarity). A. gangotriensis was determined as positive lipase producer based on the plate screening using specific and sensitive plate assay of Rhodamine B. The PCR result using Arthrobacter sp.’s full lipase gene sequence as the template primers emphasised a possible lipase gene at 900 bp band size. The gene is further cloned in a suitable vector system for expression of lipase. PMID:27965754

  9. Psychrophilic yeasts from worldwide glacial habitats: diversity, adaptation strategies and biotechnological potential.

    PubMed

    Buzzini, Pietro; Branda, Eva; Goretti, Marta; Turchetti, Benedetta

    2012-11-01

    Glacial habitats (cryosphere) include some of the largest unexplored and extreme biospheres on Earth. These habitats harbor a wide diversity of psychrophilic prokaryotic and eukaryotic microorganisms. These highly specialized microorganisms have developed adaptation strategies to overcome the direct and indirect life-endangering influence of low temperatures. For many years Antarctica has been the geographic area preferred by microbiologists for studying the diversity of psychrophilic microorganisms (including yeasts). However, there have been an increasing number of studies on psychrophilic yeasts sharing the non-Antarctic cryosphere. The present paper provides an overview of the distribution and adaptation strategies of psychrophilic yeasts worldwide. Attention is also focused on their biotechnological potential, especially on their exploitation as a source of cold-active enzymes and for bioremediation purposes.

  10. Some like it cold: understanding the survival strategies of psychrophiles

    PubMed Central

    De Maayer, Pieter; Anderson, Dominique; Cary, Craig; Cowan, Don A

    2014-01-01

    Much of the Earth’s surface, both marine and terrestrial, is either periodically or permanently cold. Although habitats that are largely or continuously frozen are generally considered to be inhospitable to life, psychrophilic organisms have managed to survive in these environments. This is attributed to their innate adaptive capacity to cope with cold and its associated stresses. Here, we review the various environmental, physiological and molecular adaptations that psychrophilic microorganisms use to thrive under adverse conditions. We also discuss the impact of modern “omic” technologies in developing an improved understanding of these adaptations, highlighting recent work in this growing field. PMID:24671034

  11. Progress and challenges in the engineering of non-cellulolytic microorganisms for consolidated bioprocessing.

    PubMed

    den Haan, Riaan; van Rensburg, Eugéne; Rose, Shaunita H; Görgens, Johann F; van Zyl, Willem H

    2015-06-01

    Lignocellulosic biomass is an abundant, renewable feedstock for the production of fuels and chemicals, if an efficient and affordable conversion technology can be established to overcome its recalcitrance. Consolidated bioprocessing (CBP) featuring enzyme production, substrate hydrolysis and fermentation in a single step is a biologically mediated conversion approach with outstanding potential if a fit-for-purpose microorganism(s) can be developed. Progress in developing CBP-enabling microorganisms is ongoing by engineering (i) naturally cellulolytic microorganisms for improved product-related properties or (ii) non-cellulolytic organisms exhibiting high product yields to heterologously produce different combinations of cellulase enzymes. We discuss progress on developing yeast and bacteria for the latter strategy and consider further challenges that require attention to bring this technology to market.

  12. Dry-heat resistance of selected psychrophiles.

    PubMed

    Winans, L; Pflug, I J; Foster, T L

    1977-08-01

    The dry-heat resistance characteristics of spores of psychrophilic organisms isolated from soil samples from the Viking spacecraft assembly areas at Cape Kennedy Space Flight Center, Cape Canaveral, Fla., were studied. Spore suspensions were produced, and dry-heat D values were determined for the microorganisms that demonstrated growth or survival under a simulated Martian environment. The dry-heat tests were carried out by using the planchet-boat-hot plate system at 110 and 125 degrees C with an ambient relative humidity of 50% at 22 degrees C. The spores evaluated had a relatively low resistance to dry heat. D(110 degrees C) values ranged from 7.5 to 122 min, whereas the D(123 degrees C) values ranged from less than 1.0 to 9.8 min.

  13. Meeting the challenges of toxic microorganisms and pathogens: Implications for food safety and public health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An interdisciplinary approach is needed to meet the longstanding and emerging challenges for protecting animals and humans from illnesses caused by feed- or food-borne microorganisms and their toxins. The reports in this special issue illustrate some components of a broad-based approach for charact...

  14. The structure of ferricytochrome c552 from the psychrophilic marine bacterium Colwellia psychrerythraea 34H

    PubMed Central

    Harvilla, Paul B.; Wolcott, Holly N.

    2014-01-01

    Approximately 40% of all proteins are metalloproteins, and approximately 80% of Earth’s ecosystems are at temperatures ≤ 5 °C, including 90% of the global ocean. Thus, an essential aspect of marine metallobiochemistry is an understanding of the structure, dynamics, and mechanisms of cold adaptation of metalloproteins from marine microorganisms. Here, the molecular structure of the electron-transfer protein cytochrome c552 from the psychrophilic marine bacterium Colwellia psychrerythraea 34H has been determined by X-ray crystallography (PDB: 4O1W). The structure is highly superimposable with that of the homologous cytochrome from the mesophile Marinobacter hydrocarbonoclasticus. Based on structural analysis and comparison of psychrophilic, psychrotolerant, and mesophilic sequences, a methionine-based ligand-substitution mechanism for psychrophilic protein stabilization is proposed. PMID:24727932

  15. Plasmids of psychrophilic and psychrotolerant bacteria and their role in adaptation to cold environments

    PubMed Central

    Dziewit, Lukasz; Bartosik, Dariusz

    2014-01-01

    Extremely cold environments are a challenge for all organisms. They are mostly inhabited by psychrophilic and psychrotolerant bacteria, which employ various strategies to cope with the cold. Such harsh environments are often highly vulnerable to the influence of external factors and may undergo frequent dynamic changes. The rapid adjustment of bacteria to changing environmental conditions is crucial for their survival. Such “short-term” evolution is often enabled by plasmids—extrachromosomal replicons that represent major players in horizontal gene transfer. The genomic sequences of thousands of microorganisms, including those of many cold-active bacteria have been obtained over the last decade, but the collected data have yet to be thoroughly analyzed. This report describes the results of a meta-analysis of the NCBI sequence databases to identify and characterize plasmids of psychrophilic and psychrotolerant bacteria. We have performed in-depth analyses of 66 plasmids, almost half of which are cryptic replicons not exceeding 10 kb in size. Our analyses of the larger plasmids revealed the presence of numerous genes, which may increase the phenotypic flexibility of their host strains. These genes encode enzymes possibly involved in (i) protection against cold and ultraviolet radiation, (ii) scavenging of reactive oxygen species, (iii) metabolism of amino acids, carbohydrates, nucleotides and lipids, (iv) energy production and conversion, (v) utilization of toxic organic compounds (e.g., naphthalene), and (vi) resistance to heavy metals, metalloids and antibiotics. Some of the plasmids also contain type II restriction-modification systems, which are involved in both plasmid stabilization and protection against foreign DNA. Moreover, approx. 50% of the analyzed plasmids carry genetic modules responsible for conjugal transfer or mobilization for transfer, which may facilitate the spread of these replicons among various bacteria, including across species

  16. A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission

    NASA Technical Reports Server (NTRS)

    Foster, T. L.; Winans, L., Jr.

    1973-01-01

    The sampling of soils from the manufacture and assembly areas of the Viking spacecraft is reported and the methodology employed in the analysis of these samples for psychrophilic microorganisms, and temperature studies on these organisms is outlined. Results showing the major types of organisms and the percentage of obligate psychrophiles in each sample are given and discussed. Emphasis in all areas is toward application of these results to the objectives of the planetary quarantine program.

  17. Isolation and physiological characterization of psychrophilic denitrifying bacteria from permanently cold Arctic fjord sediments (Svalbard, Norway).

    PubMed

    Canion, Andy; Prakash, Om; Green, Stefan J; Jahnke, Linda; Kuypers, Marcel M M; Kostka, Joel E

    2013-05-01

    A large proportion of reactive nitrogen loss from polar sediments is mediated by denitrification, but microorganisms mediating denitrification in polar environments remain poorly characterized. A combined approach of most-probable-number (MPN) enumeration, cultivation and physiological characterization was used to describe psychrophilic denitrifying bacterial communities in sediments of three Arctic fjords in Svalbard (Norway). A MPN assay showed the presence of 10(3) -10(6) cells of psychrophilic nitrate-respiring bacteria g(-1) of sediment. Fifteen strains within the Proteobacteria were isolated using a systematic enrichment approach with organic acids as electron donors and nitrate as an electron acceptor. Isolates belonged to five genera, including Shewanella, Pseudomonas, Psychromonas (Gammaproteobacteria), Arcobacter (Epsilonproteobacteria) and Herminiimonas (Betaproteobacteria). All isolates were denitrifiers, except Shewanella, which exhibited the capacity for dissimilatory nitrate reduction to ammonium (DNRA). Growth from 0 to 40°C demonstrated that all genera except Shewanella were psychrophiles with optimal growth below 15°C, and adaptation to low temperature was demonstrated as a shift from primarily C16:0 saturated fatty acids to C16:1 monounsaturated fatty acids at lower temperatures. This study provides the first targeted enrichment and characterization of psychrophilic denitrifying bacteria from polar sediments, and two genera, Arcobacter and Herminiimonas, are isolated for the first time from permanently cold marine sediments.

  18. Isolation and Physiological Characterization of Psychrophilic Denitrifying Bacteria from Permanently Cold Arctic Fjord Sediments (Svalbard, Norway)

    NASA Technical Reports Server (NTRS)

    Canion, Andy; Prakash, Om; Green, Stefan J.; Jahnke, Linda; Kuypers, Marcel M. M.; Kostka, Joel E.

    2013-01-01

    A large proportion of reactive nitrogen loss from polar sediments is mediated by denitrification, but microorganisms mediating denitrification in polar environments remain poorly characterized. A combined approach of most-probable-number (MPN) enumeration, cultivation and physiological characterization was used to describe psychrophilic denitrifying bacterial communities in sediments of three Arctic fjords in Svalbard (Norway). A MPN assay showed the presence of 10(sup 3)-10(sup 6) cells of psychrophilic nitrate-respiring bacteria g(sup -1) of sediment. Fifteen strains within the Proteobacteria were isolated using a systematic enrichment approach with organic acids as electron donors and nitrate as an electron acceptor. Isolates belonged to five genera, including Shewanella, Pseudomonas, Psychromonas (Gammaproteobacteria), Arcobacter (Epsilonproteobacteria) and Herminiimonas (Betaproteobacteria). All isolates were denitrifiers, except Shewanella, which exhibited the capacity for dissimilatory nitrate reduction to ammonium (DNRA). Growth from 0 to 40 degC demonstrated that all genera except Shewanella were psychrophiles with optimal growth below 15 degC, and adaptation to low temperature was demonstrated as a shift from primarily C16:0 saturated fatty acids to C16:1 monounsaturated fatty acids at lower temperatures. This study provides the first targeted enrichment and characterization of psychrophilic denitrifying bacteria from polar sediments, and two genera, Arcobacter and Herminiimonas, are isolated for the first time from permanently cold marine sediments.

  19. A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission

    NASA Technical Reports Server (NTRS)

    Foster, T. L.; Winans, L., Jr.

    1974-01-01

    The ability of psychrophilic microorganisms to grow in some of the environmental conditions suggested for Mars is studied with particular attention given to the effects of moisture and nutrients on growth. Results of growth with the slide culture technique are presented and indicate that this technique can be a rapid and sensitive technique for demonstration of microbial growth under various environmental conditions. Additional soil samples have been obtained from Cape Kennedy, and results of these assays at various low temperatures for psychrophilic populations are presented. The heat resistance of some of the psychrophilic sporeformers have been determined. Psychrophilic organisms were isolated from the teflon ribbons at Cape Kennedy and characterization of these was begun. In addition, heat survivors from the teflon ribbons are being investigated, and partial characterizations of these are presented.

  20. Psychrophilic and Psychrotolerant Microbial Extremophiles in Polar Environments

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Pikuta, Elena V.

    2010-01-01

    The microbial extremophiles that inhabit the polar regions of our planet are of tremendous significance. The psychrophilic and psychrotolerant microorganisms, which inhabit all of the cold environments on Earth have important applications to Bioremediation, Medicine, Pharmaceuticals, and many other areas of Biotechnology. Until recently, most of the research on polar microorganisms was confined to studies of polar diatoms, yeast, fungi and cyanobacteria. However, within the past three decades, extensive studies have been conducted to understand the bacteria and archaea that inhabit the Arctic and Antarctic sea-ice, glaciers, ice sheets, permafrost and the cryptoendolithic, cryoconite and ice-bubble environments. These investigations have resulted in the discovery of many new genera and species of anaerobic and aerobic microbial extremophiles. Exotic enzymes, cold-shock proteins and pigments produced by some of the extremophiles from polar environments have the potential to be of great benefit to Mankind. Knowledge about microbial life in the polar regions is crucial to understanding the limitations and biodiversity of life on Earth and may provide valuable clues to the Origin of Life on Earth. The discovery of viable microorganisms in ancient ice from the Fox Tunnel, Alaska and the deep Vostok Ice has shown that microorganisms can remain alive while cryopreserved in ancient ice. The psychrophilic lithoautotrophic homoacetogen isolated from the deep anoxic trough of Lake Untersee is an ideal candidate for life that might inhabit comets or the polar caps of Mars. The spontaneous release of gas from within the Anuchin Glacier above Lake Untersee may provide clues to the ice geysers that erupt from the tiger stripe regions of Saturn s moon Enceladus. The methane productivity in the lower regimes of Lake Untersee may also provide insights into possible mechanisms for the recently discovered methane releases on Mars. Since most of the other water bearing bodies of our

  1. A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission, 1 January - 30 June 1973

    NASA Technical Reports Server (NTRS)

    Foster, T. L.; Winans, L., Jr.

    1973-01-01

    Soil samples from the areas associated with the Viking spacecraft were analyzed for major generic groups of microorganisms and the percentage of obligate psychrophiles. Results are presented which show the distribution of organisms isolated at low temperatures and the methods employed for subjecting samples to simulated Martian conditions. Emphasis is placed on application of these results to the objectives of the quarantine program.

  2. Quantitative ecology and dry-heat resistance of psychrophiles. M.S. Thesis; [in soil samples from Viking spacecraft manufacturing areas

    NASA Technical Reports Server (NTRS)

    Winans, L., Jr.

    1974-01-01

    Microorganisms capable of growth at 7 C were enumerated and isolated from soil samples from the manufacture area (Denver, Colorado) and assembly area (Cape Kennedy, Florida) of the Viking spacecraft. Temperature requirements were determined for these isolates, and those growing at 3 C, but not at 32 C were designated as obligate psychrophiles in this investigation. These were identified to major generic groups, and the population density of obligate psychrophiles from the various groups was determined. Dry heat D-values were found for those spores that demonstrated growth or survival under a simulated Martian environment.

  3. Psychrophilic Biomass Producers in the Trophic Chain of the Microbial Community of Lake Untersee, Antarctica

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.

    2010-01-01

    The study of photosynthetic microorganisms from the Lake Untersee samples showed dispersed distribution of phototrophs within 80 m water column. Lake Untersee represents a unique ecosystem that experienced complete isolation: sealed by the Anuchin Glacier for many millennia. Consequently, its biocenosis has evolved over a significant period of time without exchange or external interaction with species from other environments. The major producers of organic matter in Lake Untersee are represented by phototrophic and chemolithotrophic microorganisms. This is the traditional trophic scheme for lacustrine ecosystems on Earth. Among the phototrophs, diatoms were not found, which differentiates this lake from other known ecosystems. The dominant species among phototrophs was Chlamydomonas sp. with typical morphostructure: green chloroplasts, bright red round spot, and two polar flagella near the opening. As expected, the physiology of studied phototrophs was limited by low temperature, which defined them as obligate psychrophilic microorganisms. By the quantity estimation of methanogenesis in this lake, the litho-autotrophic production of organic matter is competitive with phototrophic production. However, pure cultures of methanogens have not yet been obtained. We discuss the primary producers of organic matter and the participation of our novel psychrophilic homoacetogen into the litho-autotrophic link of biomass production in Lake Untersee.

  4. Antimicrobial activity of zinc oxide particles on five micro-organisms of the Challenge Tests related to their physicochemical properties.

    PubMed

    Pasquet, Julia; Chevalier, Yves; Couval, Emmanuelle; Bouvier, Dominique; Noizet, Gaëlle; Morlière, Cécile; Bolzinger, Marie-Alexandrine

    2014-01-02

    Zinc oxide is commonly used in pharmaceutical products to prevent or treat topical or systemic diseases owing to its antimicrobial properties, but it is scarcely used as preservative in topical formulations. The aim of this work was to investigate the antimicrobial activity of zinc oxide (ZnO) powders on the five microbial strains used for Challenge Tests in order to evaluate this inorganic compound as a preservative in topical formulation and assess relationships between the structural parameters of ZnO particles and their antimicrobial activity. For this purpose, the physicochemical characteristics of three ZnO grades were measured and their antimicrobial efficacy against the following micro-organisms - Escherichia coli; Staphylococcus aureus; Pseudomonas aeruginosa; Candida albicans; Aspergillus brasiliensis - was assessed using disc diffusion susceptibility tests and a broth dilution method. The comprehensive dataset of physicochemical characteristics and antimicrobial activities (MIC and MBC) is discussed regarding methodological issues related to the particulate nature of ZnO and structure-activity relationships. Every ZnO grade showed bactericidal and antifungal activity against the five tested micro-organisms in a concentration dependent manner. ZnO particles with smaller size, larger specific area and higher porosity exhibit higher antimicrobial activity. Such trends are related to their mechanisms of antimicrobial activity.

  5. Thermolabile triose phosphate isomerase in a psychrophilic Clostridium.

    NASA Technical Reports Server (NTRS)

    Shing, Y. W.; Akagi, J. M.; Himes, R. H.

    1972-01-01

    It was found that a psychrophilic Clostridium contains a triose phosphate isomerase which is very labile at moderate temperatures. An investigation showed that the optimal growth temperature of the psychrophile was between 15 and 20 deg C. No growth occurred at 25 deg C. The thermostability of the glycolytic enzymes in the cell-free extracts of Clostridium sp. strain 69 was studied. The data obtained show that the triose phosphate isomerase is quite labile at moderate temperatures. The instability of the enzyme is sufficient to explain the low maximum growth temperature of the psychrophile.

  6. Evaluation of engineered nanoparticle toxic effect on wastewater microorganisms: current status and challenges.

    PubMed

    Eduok, S; Martin, B; Villa, R; Nocker, A; Jefferson, B; Coulon, F

    2013-09-01

    The use of engineered nanoparticles (ENPs) in a wide range of products is associated with an increased concern for environmental safety due to their potential toxicological and adverse effects. ENPs exert antimicrobial properties through different mechanisms such as the formation of reactive oxygen species, disruption of physiological and metabolic processes. Although there are little empirical evidences on environmental fate and transport of ENPs, biosolids in wastewater most likely would be a sink for ENPs. However, there are still many uncertainties in relation to ENPs impact on the biological processes during wastewater treatment. This review provides an overview of the available data on the plausible effects of ENPs on AS and AD processes, two key biologically relevant environments for understanding ENPs-microbial interactions. It indicates that the impact of ENPs is not fully understood and few evidences suggest that ENPs could augment microbial-mediated processes such as AS and AD. Further to this, wastewater components can enhance or attenuate ENPs effects. Meanwhile it is still difficult to determine effective doses and establish toxicological guidelines, which is in part due to variable wastewater composition and inadequacy of current analytical procedures. Challenges associated with toxicity evaluation and data interpretation highlight areas in need for further research studies.

  7. Structural investigation and biological activity of the lipooligosaccharide from the psychrophilic bacterium Pseudoalteromonas haloplanktis TAB 23.

    PubMed

    Carillo, Sara; Pieretti, Giuseppina; Parrilli, Ermenegilda; Tutino, Maria L; Gemma, Sabrina; Molteni, Monica; Lanzetta, Rosa; Parrilli, Michelangelo; Corsaro, Maria M

    2011-06-14

    Pseudoalteromonas haloplanktis TAB 23 is a Gram-negative psychrophilic bacterium isolated from the Antarctic coastal sea. To survive in these conditions psychrophilic bacteria have evolved typical membrane lipids and "antifreeze" proteins to protect the inner side of the microorganism. As for Gram-negative bacteria, the outer membrane is mainly constituted by lipopoly- or lipooligosaccharides (LPS or LOS, respectively), which lean towards the external environment. Despite this, very little is known about the peculiarity of LPS from Gram-negative psychrophilic bacteria and what their role is in adaptation to cold temperature. Here we report the complete structure of the LOS from P. haloplanktis TAB 23. The lipid A was characterized by MALDI-TOF MS analysis and was tested in vitro showing a significant inhibitory effect on the LPS-induced pro-inflammatory cytokine production when added in culture with LPS from Escherichia coli. The product obtained after de-O-acylation of the LPS was analyzed by MALDI-TOF MS revealing the presence of several molecular species, differing in phosphorylation degree and oligosaccharide length. The oligosaccharide portion released after strong alkaline hydrolysis was purified by anion-exchange chromatography-pulsed amperometric detection (HPAEC-PAD) to give three main fractions, characterized by means of 2D NMR spectroscopy, which showed a very short highly phosphorylated saccharidic chain with the following general structure. α-Hepp3R,6R,4R'-(1→5)-α-Kdop4P-(2→6)-β-GlcpN4R-(1→6)-α-GlcpN1P (R=-H(2)PO(3) or -H; R'=α-Galp-(1→4)-β-Galp-(1→ or H-).

  8. Genomics of an extreme psychrophile, Psychromonas ingrahamii

    SciTech Connect

    Riley, Monica; Staley, James T.; Danchin, Antoine; Wang, T.; Brettin, Tom; Hauser, Loren John; Land, Miriam L; Thompson, Linda S

    2008-05-01

    Background: The genome sequence of the sea-ice bacterium Psychromonas ingrahamii 37, which grows exponentially at -12C, may reveal features that help to explain how this extreme psychrophile is able to grow at such low temperatures. Determination of the whole genome sequence allows comparison with genes of other psychrophiles and mesophiles. Results: Correspondence analysis of the composition of all P. ingrahamii proteins showed that (1) there are 6 classes of proteins, at least one more than other bacteria, (2) integral inner membrane proteins are not sharply separated from bulk proteins suggesting that, overall, they may have a lower hydrophobic character, and (3) there is strong opposition between asparagine and the oxygen-sensitive amino acids methionine, arginine, cysteine and histidine and (4) one of the previously unseen clusters of proteins has a high proportion of "orphan" hypothetical proteins, raising the possibility these are cold-specific proteins. Based on annotation of proteins by sequence similarity, (1) P. ingrahamii has a large number (61) of regulators of cyclic GDP, suggesting that this bacterium produces an extracellular polysaccharide that may help sequester water or lower the freezing point in the vicinity of the cell. (2) P. ingrahamii has genes for production of the osmolyte, betaine choline, which may balance the osmotic pressure as sea ice freezes. (3) P. ingrahamii has a large number (11) of three-subunit TRAP systems that may play an important role in the transport of nutrients into the cell at low temperatures. (4) Chaperones and stress proteins may play a critical role in transforming nascent polypeptides into 3-dimensional configurations that permit low temperature growth. (5) Metabolic properties of P. ingrahamii were deduced. Finally, a few small sets of proteins of unknown function which may play a role in psychrophily have been singled out as worthy of future study. Conclusion: The results of this genomic analysis provide a

  9. Genomics of an extreme psychrophile, Psychromonas ingrahamii

    PubMed Central

    Riley, Monica; Staley, James T; Danchin, Antoine; Wang, Ting Zhang; Brettin, Thomas S; Hauser, Loren J; Land, Miriam L; Thompson, Linda S

    2008-01-01

    Background The genome sequence of the sea-ice bacterium Psychromonas ingrahamii 37, which grows exponentially at -12C, may reveal features that help to explain how this extreme psychrophile is able to grow at such low temperatures. Determination of the whole genome sequence allows comparison with genes of other psychrophiles and mesophiles. Results Correspondence analysis of the composition of all P. ingrahamii proteins showed that (1) there are 6 classes of proteins, at least one more than other bacteria, (2) integral inner membrane proteins are not sharply separated from bulk proteins suggesting that, overall, they may have a lower hydrophobic character, and (3) there is strong opposition between asparagine and the oxygen-sensitive amino acids methionine, arginine, cysteine and histidine and (4) one of the previously unseen clusters of proteins has a high proportion of "orphan" hypothetical proteins, raising the possibility these are cold-specific proteins. Based on annotation of proteins by sequence similarity, (1) P. ingrahamii has a large number (61) of regulators of cyclic GDP, suggesting that this bacterium produces an extracellular polysaccharide that may help sequester water or lower the freezing point in the vicinity of the cell. (2) P. ingrahamii has genes for production of the osmolyte, betaine choline, which may balance the osmotic pressure as sea ice freezes. (3) P. ingrahamii has a large number (11) of three-subunit TRAP systems that may play an important role in the transport of nutrients into the cell at low temperatures. (4) Chaperones and stress proteins may play a critical role in transforming nascent polypeptides into 3-dimensional configurations that permit low temperature growth. (5) Metabolic properties of P. ingrahamii were deduced. Finally, a few small sets of proteins of unknown function which may play a role in psychrophily have been singled out as worthy of future study. Conclusion The results of this genomic analysis provide a

  10. Dry-heat resistance of selected psychrophiles. [Viking lander in spacecraft sterilization

    NASA Technical Reports Server (NTRS)

    Winans, L.; Pflug, I. J.; Foster, T. L.

    1977-01-01

    The dry-heat resistance characteristics of spores of psychrophilic organisms isolated from soil samples from the Viking spacecraft assembly areas at Cape Kennedy Space Flight Center, Cape Canaveral, Fla., were studied. Spore suspensions were produced, and dry-heat D values were determined for the microorganisms that demonstrated growth or survival under a simulated Martian environment. The dry-heat tests were carried out by using the planchet-boat-hot plate system at 110 and 125 C with an ambient relative humidity of 50% at 22 C. The spores evaluated had a relatively low resistance to dry heat. D (110 C) values ranged from 7.5 to 122 min, whereas the D (125 C) values ranged from less than 1.0 to 9.8 min.

  11. Microorganism immobilization

    DOEpatents

    Compere, Alicia L.; Griffith, William L.

    1981-01-01

    Live metabolically active microorganisms are immobilized on a solid support by contacting particles of aggregate material with a water dispersible polyelectrolyte such as gelatin, crosslinking the polyelectrolyte by reacting it with a crosslinking agent such as glutaraldehyde to provide a crosslinked coating on the particles of aggregate material, contacting the coated particles with live microorganisms and incubating the microorganisms in contact with the crosslinked coating to provide a coating of metabolically active microorganisms. The immobilized microorganisms have continued growth and reproduction functions.

  12. Identity and physiology of a new psychrophilic eukaryotic green alga, Chlorella sp., strain BI, isolated from a transitory pond near Bratina Island, Antarctica

    USGS Publications Warehouse

    Morgan-Kiss, R. M.; Ivanov, A.G.; Modla, S.; Czymmek, K.; Huner, N.P.A.; Priscu, J.C.; Lisle, J.T.; Hanson, T.E.

    2008-01-01

    Permanently low temperature environments are one of the most abundant microbial habitats on earth. As in most ecosystems, photosynthetic organisms drive primary production in low temperature food webs. Many of these phototrophic microorganisms are psychrophilic; however, functioning of the photosynthetic processes of these enigmatic psychrophiles (the 'photopsychrophiles') in cold environments is not well understood. Here we describe a new chlorophyte isolated from a low temperature pond, on the Ross Ice Shelf near Bratina Island, Antarctica. Phylogenetic and morphological analyses place this strain in the Chlorella clade, and we have named this new chlorophyte Chlorella BI. Chlorella BI is a psychrophilic species, exhibiting optimum temperature for growth at around 10??C. However, psychrophily in the Antarctic Chlorella was not linked to high levels of membrane-associated poly-unsaturated fatty acids. Unlike the model Antarctic lake alga, Chlamydomonas raudensis UWO241, Chlorella BI has retained the ability for dynamic short term adjustment of light energy distribution between photosystem II (PS II) and photosystem I (PS I). In addition, Chlorella BI can grow under a variety of trophic modes, including heterotrophic growth in the dark. Thus, this newly isolated photopsychrophile has retained a higher versatility in response to environmental change than other well studied cold-adapted chlorophytes. ?? 2008 Springer.

  13. Global microbial commons: institutional challenges for the global exchange and distribution of microorganisms in the life sciences.

    PubMed

    Dedeurwaerdere, Tom

    2010-01-01

    Exchanges of microorganisms between culture collections, laboratories and researchers worldwide have historically occurred in an informal way. These informal exchanges have facilitated research activities, and, as a consequence, our knowledge and exploitation of microbial resources have advanced rapidly. During the last decades of the twentieth century, the increasing economic importance of biotechnology and the introduction of new legislation concerning the use of and access to biological resources has subjected exchanges of genetic resources to greater controls. Their access and distribution are more strictly regulated and, therefore, exchanges are becoming more and more formalized. This paper analyzes one of the main drivers of the movement toward more formal worldwide exchange regimes, which is increasing global interdependency of access to genetic resources. Its main finding is that formalization of exchange practices as such is not necessarily leading to more restrictive licensing conditions. The goal of further formalization and harmonization of institutional frameworks should therefore be to provide the broadest possible access to essential research materials (within the constraints set by biosecurity and quality management requirements), while maximizing the reciprocity benefits of access and exchange (which motivate the exchange practices to start with).

  14. Anaerobic Psychrophiles from Alaska, Antarctica, and Patagonia: Implications to Possible Life on Mars and Europa

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Pikuta, Elena V.; Marsic, Damien; Ng, Joseph

    2002-01-01

    Microorganisms preserved within the permafrost, glaciers, and polar ice sheets of planet Earth provide analogs for microbial life forms that may be encountered in ice or permafrost of Mars, Europa, Callisto, Ganymede, asteroids, comets or other frozen worlds in the Cosmos. The psychrophilic and psychrotolerant microbes of the terrestrial cryosphere help establish the thermal and temporal limitations of life on Earth and provide clues to where and how we should search for evidence of life elsewhere in the Universe. For this reason, the cold-loving microorganisms are directly relevant to Astrobiology. Cryopreserved microorganisms can remain viable (in deep anabiosis) in permafrost and ice for millions of years. Permafrost, ice wedges, pingos, glaciers, and polar ice sheets may contain intact ancient DNA, lipids, enzymes, proteins, genes, and even frozen and yet viable ancient microbiota. Some microorganisms carry out metabolic processes in water films and brine, acidic, or alkaline channels in permafrost or ice at temperatures far below 0 C. Complex microbial communities live in snow, ice-bubbles, cryoconite holes on glaciers and ancient microbial ecosystems are cryopreserved within the permafrost, glaciers, and polar caps. In the Astrobiology group of the NASA Marshall Space Flight Center and the University of Alabama at Huntsville, we have employed advanced techniques for the isolation, culture, and phylogenetic analysis of many types of microbial extremophiles. We have also used the Environmental Scanning Electron Microscope to study the morphology, ultra-microstructure and chemical composition of microorganisms in ancient permafrost and ice. We discuss several interesting and novel anaerobic microorganisms that we have isolated and cultured from the Pleistocene ice of the Fox Tunnel of Alaska, guano of the Magellanic Penguin, deep-sea sediments from the vicinity of the Rainbow Hydrothermal Vent and enrichment cultures from ice of the Patriot Hills of Antarctica

  15. Anaerobic Psychrophiles from Alaska, Antarctica, and Patagonia: Implications to Possible Life on Mars and Europa

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Pikuta, Elena V.; Marsic, Damien; Ng, Joseph; Six, N. Frank (Technical Monitor)

    2001-01-01

    Microorganisms preserved within the permafrost, glaciers, and polar ice sheets of planet Earth provide analogs for microbial life forms that may be encountered in ice or permafrost of Mars, Europa, Callisto, Ganymede, asteroids, comets or other frozen worlds in the Cosmos. The psychrophilic and psychrotolerant microbes of the terrestrial cryosphere help establish the thermal and temporal limitations of life on Earth and provide clues to where and how we should search for evidence of life elsewhere in the Universe. For this reason, the cold-loving microorganisms are directly relevant to Astrobiology. Cryo-preserved microorganisms can remain viable (in deep anabiosis) in permafrost and ice for millions of years. Permafrost, ice wedges, pingos, glaciers, and polar ice sheets may contain intact ancient DNA, lipids, enzymes, proteins, genes, and even frozen and yet viable ancient microbiota. Some microorganisms carry out metabolic processes in water films and brine, acidic, or alkaline channels in permafrost or ice at temperatures far below 0 T. Complex microbial communities live in snow, ice-bubbles, cryoconite holes on glaciers and ancient microbial ecosystems are cryopreserved within the permafrost, glaciers, and polar caps. In the Astrobiology group of the NASA Marshall Space Flight Center and the University of Alabama at Huntsville, we have employed advanced techniques for the isolation, culture, and phylogenetic analysis of many types of microbial extremophiles. We have also used the Environmental Scanning Electron Microscope to study the morphology, ultra-microstructure and chemical composition of microorganisms in ancient permafrost and ice. We discuss several interesting and novel anaerobic microorganisms that we have isolated and cultured from the Pleistocene ice of the Fox Tunnel of Alaska, guano of the Magellanic Penguin, deep sea sediments from the vicinity of the Rainbow Hydrothermal Vent and enrichment cultures from ice of the Patriot Hills of Antarctica

  16. Anaerobic psychrophiles from Lake Zub and Lake Untersee, Antarctica

    NASA Astrophysics Data System (ADS)

    Townsend, Alisa; Pikuta, Elena V.; Guisler, Melissa; Stahl, Sarah; Hoover, Richard B.

    2009-08-01

    The study of samples from Antarctica 2008 and 2009 expeditions organized and successfully conducted by Richard Hoover led to the isolation of diverse anaerobic strains with psychrotolerant and psychrophilic physiology. Due to the fact that Lake Untersee has never been subject to microbiological study, this work with the samples has significant and pioneering impact to the knowledge about the biology of this unique ecosystem. Also, the astrobiological significance for the study of these ecosystems is based on new findings of ice covered water systems on other bodies of our solar system. Anaerobic psychrotolerant strain LZ-22 was isolated from a frozen sample of green moss with soils around the rhizosphere collected near Lake Zub in Antarctica. Morphology of strain LZ-22 was observed to be motile, rod shaped and spore-forming cells with sizes 1 x 5-10 μm. This new isolate is a mesophile with the maximum temperature of growth at 40°C. Strain LZ-22 is able to live on media without NaCl and in media with up to 7 % (w/v) NaCl. It is catalase negative and grows only on sugars with the best growth rate being on lactose. The strain is a neutrophile and grows between pH 5 and 9.0 with the optimum at 7.8. Another two strains UL7-96mG and LU-96m7P were isolated from deep water samples of Lake Untersee. Proteolytic strain LU-96m7P had a truly psychrophilic nature and refused to grow at room temperature. Sugarlytic strain UL7-96mG was found to be psychrotolerant, but its rate of growth at 3°C was very high compared with other mesophiles. Two homoacetogenic psychrophilic strains A7AC-96m and AC-DS7 were isolated and purified from samples of Lake Untersee; both of them are able to grow chemolithotrophically on H2+CO2. In the presence of lactate, these strains are able to grow only at 0-18 °C, and growth at 22 °C was observed only with yeast extract stimulation. In this paper, physiological and morphological characteristics of novel psychrophilic and psychrotolerant isolates

  17. Anaerobic Psychrophiles from Lake Zub and Lake Untersee, Antarctica

    NASA Technical Reports Server (NTRS)

    Townsend, Alisa; Pikuta, Elena V.; Guisler, Melissa; Stahl, Sarah; Hoover, Richard B.

    2009-01-01

    The study of samples from Antarctica 2008 and 2009 expeditions organized and successfully conducted by Richard Hoover led to the isolation of diverse anaerobic strains with psychrotolerant and psychrophilic physiology. Due to the fact that Lake Untersee has never been subject to microbiological study, this work with the samples has significant and pioneering impact to the knowledge about the biology of this unique ecosystem. Also, the astrobiological significance for the study of these ecosystems is based on new findings of ice covered water systems on other bodies of our solar system. Anaerobic psychrotolerant strain LZ-22 was isolated from a frozen sample of green moss with soils around the rhizosphere collected near Lake Zub in Antarctica. Morphology of strain LZ-22 was observed to be motile, rod shaped and spore-forming cells with sizes 1 x 5-10 micron. This new isolate is a mesophile with the maximum temperature of growth at 40C. Strain LZ-22 is able to live on media without NaCl and in media with up to 7% (w/v) NaCl. It is catalase negative and grows only on sugars with the best growth rate being on lactose. The strain is a neutrophile and grows between pH 5 and 9.0 with the optimum at 7.8. Another two strains UL7-96mG and LU-96m7P were isolated from deep water samples of Lake Untersee. Proteolytic strain LU-96m7P had a truly psychrophilic nature and refused to grow at room temperature. Sugarlytic strain UL7-96mG was found to be psychrotolerant, but its rate of growth at 3C was very high compared with other mesophiles. Two homoacetogenic psychrophilic strains A7AC-96m and AC-DS7 were isolated and purified from samples of Lake Untersee; both of them are able to grow chemolithotrophically on H2+CO2. In the presence of lactate, these strains are able to grow only at 0-18C, and growth at 22C was observed only with yeast extract stimulation. In this paper, physiological and morphological characteristics of novel psychrophilic and psychrotolerant isolates from

  18. Psychrophilic enzymes: from folding to function and biotechnology.

    PubMed

    Feller, Georges

    2013-01-01

    Psychrophiles thriving permanently at near-zero temperatures synthesize cold-active enzymes to sustain their cell cycle. Genome sequences, proteomic, and transcriptomic studies suggest various adaptive features to maintain adequate translation and proper protein folding under cold conditions. Most psychrophilic enzymes optimize a high activity at low temperature at the expense of substrate affinity, therefore reducing the free energy barrier of the transition state. Furthermore, a weak temperature dependence of activity ensures moderate reduction of the catalytic activity in the cold. In these naturally evolved enzymes, the optimization to low temperature activity is reached via destabilization of the structures bearing the active site or by destabilization of the whole molecule. This involves a reduction in the number and strength of all types of weak interactions or the disappearance of stability factors, resulting in improved dynamics of active site residues in the cold. These enzymes are already used in many biotechnological applications requiring high activity at mild temperatures or fast heat-inactivation rate. Several open questions in the field are also highlighted.

  19. Classifying Microorganisms.

    ERIC Educational Resources Information Center

    Baker, William P.; Leyva, Kathryn J.; Lang, Michael; Goodmanis, Ben

    2002-01-01

    Focuses on an activity in which students sample air at school and generate ideas about how to classify the microorganisms they observe. The results are used to compare air quality among schools via the Internet. Supports the development of scientific inquiry and technology skills. (DDR)

  20. Halophilic-Psychrophilic Bacteria from Tirich Mir Glacier, Pakistan, as Potential Candidate for Astrobiological Studies

    NASA Astrophysics Data System (ADS)

    Rafiq, M. R.; Anesio, A. M. A.; Hayat, M. H.; Zada, S. Z.; Sajjad, W. S.; Shah, A. A. S.; Hasan, F. H.

    2016-09-01

    Hindu Kush, Karakoram, and Himalaya region is referred to as 'third pole' and could be suitable as a terrestrial analog of Mars and increased possibility of finding polyextremophiles. Study is focused on halophilic psychrophiles.

  1. Isolation and Identification of Psychrophilic Species of Bacillus from Milk

    PubMed Central

    Shehata, T. E.; Collins, E. B.

    1971-01-01

    Forty isolates from 97 raw milk samples (heated to 80 C for 10 min and stored at 4 to 7 C for 3 to 4 weeks) were sporeforming, aerobic, gram-positive or gram-variable, rod-shaped bacteria. Fifteen isolates that were identified had characteristics similar to species of Bacillus, except that they had lower growth temperature ranges, were gram-variable, and were somewhat different in sugar fermentations. Four isolates grew well within 2 weeks at 0 C, but they grew faster at 20 to 25 C. These psychrophilic sporeforming bacteria, the importance of which is discussed, are considered to be variant strains of mesophilic bacilli adapted to low temperatures. PMID:5108104

  2. Microorganism billiards

    NASA Astrophysics Data System (ADS)

    Spagnolie, Saverio E.; Wahl, Colin; Lukasik, Joseph; Thiffeault, Jean-Luc

    2017-02-01

    Recent experiments and numerical simulations have shown that certain types of microorganisms "reflect" off of a flat surface at a critical angle of departure, independent of the angle of incidence. The nature of the reflection may be active (cell and flagellar contact with the surface) or passive (hydrodynamic) interactions. We explore the billiard-like motion of a body with this empirical reflection law inside a regular polygon and show that the dynamics can settle on a stable periodic orbit or can be chaotic, depending on the swimmer's departure angle and the domain geometry. The dynamics are often found to be robust to the introduction of weak random fluctuations. The Lyapunov exponent of swimmer trajectories can be positive or negative, can have extremal values, and can have discontinuities depending on the degree of the polygon. A passive sorting device is proposed that traps swimmers of different departure angles into separate bins. We also study the external problem of a microorganism swimming in a patterned environment of square obstacles, where the departure angle dictates the possibility of trapping or diffusive trajectories.

  3. Photosynthetic and Respiratory Rates of Two Psychrophilic Diatoms 1

    PubMed Central

    Van Baalen, Chase

    1985-01-01

    The photosynthetic rates in two psychrophilic diatoms, Chaetoceros sp. strain K3-10 and Nitzschia sp. K3-3 for cells grown at 0°C were 8 to 10 microliters O2 evolved per milligram dry weight per hour, and 10-fold higher, about 80 for cells grown at 10°C. The respiration rates followed the same pattern, with a value of around 1 microliter dark uptake per milligram dry weight per hour for both organisms grown at 0°C, and 6 to 10 for cells grown at 10°C. When cells grown at 0°C were immediately shifted to 10°C or cells grown at 10°C were shifted to 0°C, the respiratory rates quickly adapted to values characteristic of cells grown at the shift temperature. On the other hand, the light-saturated rate of O2 evolution showed much less immediate adaptation, especially on the up shift, 0° to 10°C. The chlorophyll a content of 0°C grown cells was about 0.5% of dry weight, in 10°C grown cells 1.3% (strain K3-10) and 2.2% (strain K3-3). In addition to a diminished chlorophyll a content in 0°C grown cells, there seemed proportionally (by absorbance and calculation) less c to a than in 10°C grown cells. The relative fluorescence excitation spectra of 680-nm emission also showed a lower contribution by both chlorophyll c and fucoxanthin in 0°C grown cells of Chaetoceros sp. strain K3-10 as compared to 10°C grown cells. The data at hand suggest that in psychrophilic diatoms continuously growing at 0°C there may be problems associated with synthesis of an effective accessory pigment system, and as a working hypothesis it is suggested this is related to restriction of synthesis of one or several accessory pigment proteins. PMID:16664328

  4. Psychrophilic yeasts in glacial environments of Alpine glaciers.

    PubMed

    Turchetti, Benedetta; Buzzini, Pietro; Goretti, Marta; Branda, Eva; Diolaiuti, Guglielmina; D'Agata, Carlo; Smiraglia, Claudio; Vaughan-Martini, Ann

    2008-01-01

    The presence of psychrophilic yeasts in supra- and subglacial sediments, ice and meltwater collected from two glaciers of the Italian Alps (Forni and Sforzellina-Ortles-Cevedale group) was investigated. After incubation at 4 degrees C, subglacial sediments contained from 1.3 x 10(3) to 9.6 x 10(3) CFU of yeasts g(-1). The number of yeast cells in supraglacial sediments was c. 10-100-fold lower. A significant proportion of isolated yeasts exhibited one or more extracellular enzymatic activities (starch-degrading, lipolytic, esterolytic, proteolytic and pectinolytic activity) at 4 degrees C. Selected isolates were able to grow at 2 degrees C under laboratory-simulated in situ conditions. In all, 106 isolated yeasts were identified by MSP-PCR fingerprinting and 26S rRNA gene sequencing of the D1/D2 region as belonging to 10 species: Aureobasidium pullulans, Cryptococcus gilvescens (over 50% of the total), Cryptococcus terricolus, Mrakia gelida, Naganishia globosa, Rhodotorula glacialis, Rhodotorula psychrophenolica, Rhodotorula bacarum, Rhodotorula creatinivora and Rhodotorula laryngis. Four strains, all belonging to a new yeast species, yet to be described, were also isolated.

  5. Characterization of psychrophilic alanine racemase from Bacillus psychrosaccharolyticus.

    PubMed

    Okubo, Y; Yokoigawa, K; Esaki, N; Soda, K; Kawai, H

    1999-03-16

    A psychrophilic alanine racemase gene from Bacillus psychrosaccharolyticus was cloned and expressed in Escherichia coli SOLR with a plasmid pYOK3. The gene starting with the unusual initiation codon GTG showed higher preference for codons ending in A or T. The enzyme purified to homogeneity showed the high catalytic activity even at 0 degrees C and was extremely labile over 35 degrees C. The enzyme was found to have a markedly large Km value (5.0 microM) for the pyridoxal 5'-phosphate (PLP) cofactor in comparison with other reported alanine racemases, and was stabilized up to 50 degrees C in the presence of excess amounts of PLP. The low affinity of the enzyme for PLP may be related to the thermolability, and may be related to the high catalytic activity, initiated by the transaldimination reaction, at low temperature. The enzyme has a distinguishing hydrophilic region around the residue no. 150 in the deduced amino acid sequence (383 residues), whereas the corresponding regions of other Bacillus alanine racemases are hydrophobic. The position of the region in the three dimensional structure of C atoms of the enzyme was predicted to be in a surface loop surrounding the active site. The region may interact with solvent and reduce the compactness of the active site.

  6. [ATP pool and bioluminescence in psychrophilic bacteria Photobacterium phosphoreum].

    PubMed

    Alekserova, L É; Alenina, K A; Efremenko, E N; Mazhul', M M; Piskunova, N F; Ismailov, A D

    2014-01-01

    Bioluminescence activity and ATP pool were investigated in the culture of psychrophilic bacteria Photobacterium phosphoreum collected-from the exponential and stationary growth phases, as well as immobilized in polyvinyl alcohol (PVA) cryogel. In liquid culture, ATP pool remained at an almost a constant level throughout the luminescence cycle (over 100 h). The ATP pool in the stationary-phase and PVA-immobilizedl cells remained constant throughout their incubation in the medium (over 200 h) and in 3% NaCl solution (over 100 h): Quantitative assessment of integral photon yield and ATP pool indicated that bioluminescence decay in growing or stationary cells was not caused by limitation by the energy substrates of the luciferase reaction. Kinetic and quantitative parameters of emission activity and ATP pool excluded the possibility of formation of the aldehyde substrate for luciferase via reduction of the relevant fatty acids in NADPH and ATP-dependent reductase reaction and its oxidation in the monooxygenase reaction. Our results indicate that the aliphatic aldehyde is not utilized in the process of light emission.

  7. Structural Investigation of the Oligosaccharide Portion Isolated from the Lipooligosaccharide of the Permafrost Psychrophile Psychrobacter arcticus 273-4.

    PubMed

    Casillo, Angela; Parrilli, Ermenegilda; Filomena, Sannino; Lindner, Buko; Lanzetta, Rosa; Parrilli, Michelangelo; Tutino, Maria Luisa; Corsaro, Maria Michela

    2015-07-22

    Psychrophilic microorganisms have successfully colonized all permanently cold environments from the deep sea to mountain and polar regions. The ability of an organism to survive and grow in cryoenviroments depends on a number of adaptive strategies aimed at maintaining vital cellular functions at subzero temperatures, which include the structural modifications of the membrane. To understand the role of the membrane in the adaptation, it is necessary to characterize the cell-wall components, such as the lipopolysaccharides, that represent the major constituent of the outer membrane. The aim of this study was to investigate the structure of the carbohydrate backbone of the lipooligosaccharide (LOS) isolated from the cold-adapted Psychrobacter arcticus 273-4. The strain, isolated from a 20,000-to-30,000-year-old continuously frozen permafrost in Siberia, was cultivated at 4 °C. The LOS was isolated from dry cells and analyzed by means of chemical methods. In particular, it was degraded either by mild acid hydrolysis or by hydrazinolysis and investigated in detail by (1)H and (13)C NMR spectroscopy and by ESI FT-ICR mass spectrometry. The oligosaccharide was characterized by the substitution of the heptose residue, usually linked to Kdo in the inner core, with a glucose, and for the unusual presence of N-acetylmuramic acid.

  8. Structural Investigation of the Oligosaccharide Portion Isolated from the Lipooligosaccharide of the Permafrost Psychrophile Psychrobacter arcticus 273-4

    PubMed Central

    Casillo, Angela; Parrilli, Ermenegilda; Filomena, Sannino; Lindner, Buko; Lanzetta, Rosa; Parrilli, Michelangelo; Tutino, Maria Luisa; Corsaro, Maria Michela

    2015-01-01

    Psychrophilic microorganisms have successfully colonized all permanently cold environments from the deep sea to mountain and polar regions. The ability of an organism to survive and grow in cryoenviroments depends on a number of adaptive strategies aimed at maintaining vital cellular functions at subzero temperatures, which include the structural modifications of the membrane. To understand the role of the membrane in the adaptation, it is necessary to characterize the cell-wall components, such as the lipopolysaccharides, that represent the major constituent of the outer membrane. The aim of this study was to investigate the structure of the carbohydrate backbone of the lipooligosaccharide (LOS) isolated from the cold-adapted Psychrobacter arcticus 273-4. The strain, isolated from a 20,000-to-30,000-year-old continuously frozen permafrost in Siberia, was cultivated at 4 °C. The LOS was isolated from dry cells and analyzed by means of chemical methods. In particular, it was degraded either by mild acid hydrolysis or by hydrazinolysis and investigated in detail by 1H and 13C NMR spectroscopy and by ESI FT-ICR mass spectrometry. The oligosaccharide was characterized by the substitution of the heptose residue, usually linked to Kdo in the inner core, with a glucose, and for the unusual presence of N-acetylmuramic acid. PMID:26204948

  9. Psychrophilic versus psychrotolerant bacteria--occurrence and significance in polar and temperate marine habitats.

    PubMed

    Helmke, E; Weyland, H

    2004-07-01

    The numerical dominance and ecological role of psychrophilic bacteria in bottom sediments, sea ice, surface water and melt pools of the polar oceans were investigated using isolates, colony forming units (CFU) and metabolic activities. All sediment samples of the Southern Ocean studied showed a clear numerical dominance of cold-loving bacteria. In Arctic sediments underlying the influence of cold polar water bodies psychrophiles prevailed also but they were less dominant in sediments influenced by the warm Atlantic Water. A predominance of psychrophiles was further found in consolidated Antarctic sea ice as well as in multiyear Arctic sea ice and in melt pools on top of Arctic ice floes. A less uniform adaptation response was, however, met in polar surface waters. In the very northern part of the Fram Strait (Arctic Ocean) we found bacterial counts and activities at 1 degree C exceeding those at 22 degrees C. In surface water of the Weddell Sea (Southern Ocean) psychrophiles also dominated numerically in early autumn but the dominance declined obviously with the onset of winter-water and a decrease of chlorphyll a. Otherwise in surface water of the Southern Ocean CFUs were higher at 22 degrees C than at 1 degree C while activities were vice versa indicating at least a functional dominance of psychrophiles. Even in the temperate sediments of the German Bight true psychrophiles were present and a clear shift towards cold adapted communities in winter observed. Among the polar bacteria a more pronounced cold adaptation of Antarctic in comparison with Arctic isolates was obtained. The results and literature data indicate that stenothermic cold adapted bacteria play a significant role in the global marine environment. On the basis of the temperature response of our isolates from different habitats it is suggested to expand the definition of Morita in order to meet the cold adaptation strategies of the bacteria in the various cold habitats.

  10. Coliforms, Enterococci, Thermodurics, Thermophiles, and Psychrophiles in Untreated Farm Pond Waters

    PubMed Central

    Malaney, G. W.; Weiser, H. H.; Turner, R. O.; Van Horn, Marilyn

    1962-01-01

    Untreated waters from ten farm ponds located in central, north central, southeastern, and southwestern Ohio were examined for numbers of coliforms, enterococci, thermodurics, thermophiles, and psychrophiles. The median population densities per 100 ml water for all ponds were: coliforms, 23; enterococci, 3.6; thermodurics, 6,000; thermophiles, 450; psychrophiles, 1,000. The results indicate that these farm pond waters were only lightly polluted and suggest that farm ponds, properly maintained, are a source of raw water of high bacteriological quality, requiring a minimum of treatment to be made suitable for domestic and livestock purposes. PMID:14468809

  11. Culture-independent characterization of novel psychrophilic magnetotactic cocci from Antarctic marine sediments.

    PubMed

    Abreu, Fernanda; Carolina, Ana; Araujo, V; Leão, Pedro; Silva, Karen Tavares; Carvalho, Fabíola Marques de; Cunha, Oberdan de Lima; Almeida, Luiz Gonzaga; Geurink, Corey; Farina, Marcos; Rodelli, Daniel; Jovane, Luigi; Pellizari, Vivian H; Vasconcelos, Ana Tereza de; Bazylinski, Dennis A; Lins, Ulysses

    2016-12-01

    Magnetotactic bacteria (MTB) are a heterogeneous group of ubiquitous aquatic microorganisms capable of biomineralizing nano-sized, membrane-bound, magnetic iron-rich mineral particles called magnetosomes. MTB are found in chemically-stratified aquatic sediments and/or water columns with a wide range of salinities, moderate to high temperatures, and pH varying from neutral to strongly alkaline. MTB from very cold environments have not been investigated to any great degree and here we characterize MTB from the low temperature Antarctic maritime region. Sediment samples were collected at nine sampling sites within Admiralty Bay, King George Island (62°23'S 58°27'W) from 2009 to 2013. Samples from five sites contained MTB and those from two of these sites contained large number of magnetotactic cocci that were studied using electron microscopy and molecular techniques. The magnetotactic cocci contained magnetosomes either arranged as two or four chains or as a disorganized cluster. The crystalline habit and composition of all magnetosomes analyzed with high-resolution transmission electron microscopy and energy dispersive X-ray microanalysis were consistent with elongated prismatic crystals of magnetite (Fe3 O4 ). The retrieved 16S rRNA gene sequences from magnetically-enriched magnetotactic cocci clustered into three distinct groups affiliated with the Alphaproteobacteria class of the Proteobacteria. Novel sequences of each phylogenetic cluster were confirmed using fluorescent in situ hybridization. Metagenomic data analysis of magnetically-enriched magnetotactic cocci revealed the presence of mam genes and MTB-specific hypothetical protein coding genes. Sequence homology and phylogenetic analysis indicated that predicted proteins are related to those of cultivated alphaproteobacterial MTB. The consistent and continuous low temperature of the sediment where the magnetotactic cocci are present (always below 1°C) suggests that these MTB from maritime Antarctica are

  12. Genome Sequence of the Antarctic Psychrophile Bacterium Planococcus antarcticus DSM 14505

    PubMed Central

    Margolles, Abelardo; Gueimonde, Miguel

    2012-01-01

    Planococcus antarcticus DSM 14505 is a psychrophile bacterium that was isolated from cyanobacterial mat samples, originally collected from ponds in McMurdo, Antarctica. This orange-pigmented bacterium grows at 4°C and may possess interesting enzymatic activities at low temperatures. Here we report the first genomic sequence of P. antarcticus DSM 14505. PMID:22843594

  13. Metabolic Influence of Psychrophilic Diatoms on Travertines at the Huanglong Natural Scenic District of China

    PubMed Central

    Sun, Shiyong; Dong, Faqin; Ehrlich, Hermann; Zhao, Xueqing; Liu, Mingxue; Dai, Qunwei; Li, Qiongfang; An, Dejun; Dong, Hailiang

    2014-01-01

    Diatoms are a highly diversified group of algae that are widely distributed in aquatic ecosystems, and various species have different nutrient and temperature requirements for optimal growth. Here, we describe unusual psychrophilic diatoms of Cymbella in a travertine deposition environment in southwestern China in winter season. Travertine surfaces are colonized by these psychrophilic diatoms, which form biofilms of extracellular polysaccharide substances (EPS) with active metabolic activities in extremely cold conditions. The travertine in Huanglong, is a typical single crystalline calcite with anisotropic lattice distortions of unit cell parameters along axes of a and c, and this structure is suggestive of some level of metabolic mediation on mineralization. Near-edge X-ray absorption fine structure spectroscopy (NEXAFS) results further confirmed the occurrence of biogenic distortion of the crystal lattice of travertine calcite. Overall, our results imply that the metabolic influence of psychrophilic diatoms may be particularly important for promoting formation and dissolution of travertine in extremely cold environments of Huanglong. The EPS of psychrophilic diatoms will protect travertine from HCO3− etching and provide template for forming travertine when water re-flowing, in warm season. PMID:25522049

  14. Complete Genome Sequence of Psychrobacter alimentarius PAMC 27889, a Psychrophile Isolated from an Antarctic Rock Sample

    PubMed Central

    Lee, Jaejin; Kwon, Miye; Yang, Jae Young; Woo, Jusun; Lee, Hong Kum; Hong, Soon Gyu

    2016-01-01

    Psychrobacter alimentarius PAMC 27889, a Gram-negative, psychrophilic bacterium, was isolated from an Antarctic rock sample. Here, we report the complete genome of P. alimentarius PAMC 27889, which has the nonmevalonate methylerythritol phosphate pathway of terpenoid biosynthesis and a complete gene cluster for benzoate degradation. PMID:27445386

  15. Efficient aspartic acid production by a psychrophile-based simple biocatalyst.

    PubMed

    Tajima, Takahisa; Hamada, Mai; Nakashimada, Yutaka; Kato, Junichi

    2015-10-01

    We previously constructed a Psychrophile-based Simple bioCatalyst (PSCat) reaction system, in which psychrophilic metabolic enzymes are inactivated by heat treatment, and used it here to study the conversion of aspartic acid from fumaric acid mediated by the activity of aspartate ammonia-lyase (aspartase). In Escherichia coli, the biosynthesis of aspartic acid competes with that of L-malic acid produced from fumaric acid by fumarase. In this study, E. coli aspartase was expressed in psychrophilic Shewanella livingstonensis Ac10 heat treated at 50 °C for 15 min. The resultant PSCat could convert fumaric acid to aspartic acid without the formation of L-malic acid because of heat inactivation of psychrophilic fumarase activity. Furthermore, alginate-immobilized PSCat produced high yields of aspartic acid and could be re-used nine times. The results of our study suggest that PSCat can be applied in biotechnological production as a new approach to increase the yield of target compounds.

  16. Screening of microorganisms producing cold-active oxidoreductases to be applied in enantioselective alcohol oxidation. An Antarctic survey.

    PubMed

    Araújo, Lidiane S; Kagohara, Edna; Garcia, Thaís P; Pellizari, Vivian H; Andrade, Leandro H

    2011-01-01

    Several microorganisms were isolated from soil/sediment samples of Antarctic Peninsula. The enrichment technique using (RS)-1-(phenyl)ethanol as a carbon source allowed us to isolate 232 psychrophile/psychrotroph microorganisms. We also evaluated the enzyme activity (oxidoreductases) for enantioselective oxidation reactions, by using derivatives of (RS)-1-(phenyl)ethanol as substrates. Among the studied microorganisms, 15 psychrophile/psychrotroph strains contain oxidoreductases that catalyze the (S)-enantiomer oxidation from racemic alcohols to their corresponding ketones. Among the identified microorganisms, Flavobacterium sp. and Arthrobacter sp. showed excellent enzymatic activity. These new bacteria strains were selected for optimization study, in which the (RS)-1-(4-methyl-phenyl)ethanol oxidation was evaluated in several reaction conditions. From these studies, it was observed that Flavobacterium sp. has an excellent enzymatic activity at 10 °C and Arthrobacter sp. at 15 and 25 °C. We have also determined the growth curves of these bacteria, and both strains showed optimum growth at 25 °C, indicating that these bacteria are psychrotroph.

  17. Drug resistance in eukaryotic microorganisms.

    PubMed

    Fairlamb, Alan H; Gow, Neil A R; Matthews, Keith R; Waters, Andrew P

    2016-06-24

    Eukaryotic microbial pathogens are major contributors to illness and death globally. Although much of their impact can be controlled by drug therapy as with prokaryotic microorganisms, the emergence of drug resistance has threatened these treatment efforts. Here, we discuss the challenges posed by eukaryotic microbial pathogens and how these are similar to, or differ from, the challenges of prokaryotic antibiotic resistance. The therapies used for several major eukaryotic microorganisms are then detailed, and the mechanisms that they have evolved to overcome these therapies are described. The rapid emergence of resistance and the restricted pipeline of new drug therapies pose considerable risks to global health and are particularly acute in the developing world. Nonetheless, we detail how the integration of new technology, biological understanding, epidemiology and evolutionary analysis can help sustain existing therapies, anticipate the emergence of resistance or optimize the deployment of new therapies.

  18. Drug resistance in eukaryotic microorganisms

    PubMed Central

    Fairlamb, Alan H.; Gow, Neil A. R.; Matthews, Keith R.; Waters, Andrew P.

    2016-01-01

    Eukaryotic microbial pathogens are major contributors to illness and death globally. Although much of their impact can be controlled by drug therapy as with prokaryotic microorganisms, the emergence of drug resistance has threatened these treatment efforts. Here, we discuss the challenges posed by eukaryotic microbial pathogens and how these are similar to, or differ from, the challenges of prokaryotic antibiotic resistance. The therapies used for several major eukaryotic microorganisms are then detailed, and the mechanisms that they have evolved to overcome these therapies are described. The rapid emergence of resistance and the restricted pipeline of new drug therapies pose considerable risks to global health and are particularly acute in the developing world. Nonetheless, we detail how the integration of new technology, biological understanding, epidemiology and evolutionary analysis can help sustain existing therapies, anticipate the emergence of resistance or optimize the deployment of new therapies. PMID:27572976

  19. DENATURATION AND RENATURATION OF MALIC DEHYDROGENASE IN A CELL-FREE EXTRACT FROM A MARINE PSYCHROPHILE.

    PubMed

    BURTON, S D; MORITA, R Y

    1963-11-01

    Burton, Sheril D. (Oregon State University, Corvallis), and Richard Y. Morita. Denaturation and renaturation of malic dehydrogenase in a cell-free extract from a marine psychrophile. J. Bacteriol. 86:1019-1024. 1963.-Malic dehydrogenase from a marine psychrophilic vibrio (PS 207) was found to be heat-sensitive at 30 C, the maximal growth temperature for the organism. Initial denaturation was reversible, with maximal renaturation occurring when the denatured enzyme was slowly cooled in the presence of mercaptoethanol, reduced nicotinamide adenine dinucleotide, and malate. No renaturation occurred when these compounds were added after slow cooling, or when the renaturation mixture was rapidly cooled. Mercaptoethylamine, cysteine, glutathione, or mercaptoacetic acid could not replace mercaptoethanol. The kinetics of denaturation and renaturation suggest the presence of several malic isozymes each with different heat labilities, or that these processes are occurring in several distinct steps.

  20. Cloning and expression of phosphoglycerate mutase from the psychrophilic yeast, Glaciozyma antarctica PI12

    NASA Astrophysics Data System (ADS)

    Jaafar, Nardiah Rizwana; Bakar, Farah Diba Abu; Murad, Abdul Munir Abdul; Mahadi, Nor Muhammad

    2015-09-01

    The conversion of 3-phosphoglycerate to 2-phosphoglycerate during glycolysis and gluconeogenesis is catalyzed by phosphoglycerate mutase (PGM). Better understanding of metabolic reactions performed by this enzyme has been studied extensively in prokaryotes and eukaryotes. Here, we report a phosphoglycerate mutase from the psychrophilic yeast, Glaciozyma antarctica. cDNA encoding for PGM from G. antarctica PI12, a psychrophilic yeast isolated from sea ice at Casey Station, Antarctica was amplified. The gene was then cloned into a cloning vector and sequenced, which verified its identity as the gene putatively encoding for PGM. The recombinant protein was expressed in Escherichia coli BL21 (DE3) as inclusion bodies and this was confirmed by SDS-PAGE and Western blot.

  1. Challenges

    ERIC Educational Resources Information Center

    Moore, Thomas R.

    1975-01-01

    Domestic and international challenges facing the National Society for the Prevention of Blindness are discussed; and U.S. and Russian programs in testing and correcting children's vision, developing eye safety programs in agriculture and industry, and disseminating information concerning the detection and treatment of cataracts are compared. (SB)

  2. Challenger

    ERIC Educational Resources Information Center

    Allday, Jonathan

    2002-01-01

    The events that led to the spectacular destruction of the Space Shuttle "Challenger" in 1986 are detailed here. They show how NASA should have heeded engineers' worries over materials problems resulting from a launch in cold weather. Suggestions are made of how pupils could also learn from this tragedy. (Contains 4 figures and 2 footnotes.)

  3. Serine hydroxymethyltransferase from the cold adapted microorganism Psychromonas ingrahamii: a low temperature active enzyme with broad substrate specificity.

    PubMed

    Angelaccio, Sebastiana; Florio, Rita; Consalvi, Valerio; Festa, Guido; Pascarella, Stefano

    2012-01-01

    Serine hydroxymethyltransferase from the psychrophilic microorganism Psychromonas ingrahamii was expressed in Escherichia coli and purified as a His-tag fusion protein. The enzyme was characterized with respect to its spectroscopic, catalytic, and thermodynamic properties. The properties of the psychrophilic enzyme have been contrasted with the characteristics of the homologous counterpart from E. coli, which has been structurally and functionally characterized in depth and with which it shares 75% sequence identity. Spectroscopic measures confirmed that the psychrophilic enzyme displays structural properties almost identical to those of the mesophilic counterpart. At variance, the P. ingrahamii enzyme showed decreased thermostability and high specific activity at low temperature, both of which are typical features of cold adapted enzymes. Furthermore, it was a more efficient biocatalyst compared to E. coli serine hydroxymethyltransferase (SHMT) particularly for side reactions. Many β-hydroxy-α-amino acids are SHMT substrates and represent important compounds in the synthesis of pharmaceuticals, agrochemicals and food additives. Thanks to these attractive properties, this enzyme could have a significant potential for biotechnological applications.

  4. Endotoxin structures in the psychrophiles Psychromonas marina and Psychrobacter cryohalolentis contain distinctive acyl features.

    PubMed

    Sweet, Charles R; Alpuche, Giancarlo M; Landis, Corinne A; Sandman, Benjamin C

    2014-07-09

    Lipid A is the essential component of endotoxin (Gram-negative lipopolysaccharide), a potent immunostimulatory compound. As the outer surface of the outer membrane, the details of lipid A structure are crucial not only to bacterial pathogenesis but also to membrane integrity. This work characterizes the structure of lipid A in two psychrophiles, Psychromonas marina and Psychrobacter cryohalolentis, and also two mesophiles to which they are related using MALDI-TOF MS and fatty acid methyl ester (FAME) GC-MS. P. marina lipid A is strikingly similar to that of Escherichia coli in organization and total acyl size, but incorporates an unusual doubly unsaturated tetradecadienoyl acyl residue. P. cryohalolentis also shows structural organization similar to a closely related mesophile, Acinetobacter baumannii, however it has generally shorter acyl constituents and shows many acyl variants differing by single methylene (-CH2-) units, a characteristic it shares with the one previously reported psychrotolerant lipid A structure. This work is the first detailed structural characterization of lipid A from an obligate psychrophile and the second from a psychrotolerant species. It reveals distinctive structural features of psychrophilic lipid A in comparison to that of related mesophiles which suggest constitutive adaptations to maintain outer membrane fluidity in cold environments.

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

    PubMed

    Jehlička, Jan; Culka, Adam; Nedbalová, Linda

    2016-12-01

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

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

    NASA Astrophysics Data System (ADS)

    Jehlička, Jan; Culka, Adam; Nedbalová, Linda

    2016-12-01

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

  7. Extracellular enzymes produced by microorganisms isolated from maritime Antarctica.

    PubMed

    Loperena, Lyliam; Soria, Verónica; Varela, Hermosinda; Lupo, Sandra; Bergalli, Alejandro; Guigou, Mairan; Pellegrino, Andrés; Bernardo, Angela; Calviño, Ana; Rivas, Federico; Batista, Silvia

    2012-05-01

    Antarctic environments can sustain a great diversity of well-adapted microorganisms known as psychrophiles or psychrotrophs. The potential of these microorganisms as a resource of enzymes able to maintain their activity and stability at low temperature for technological applications has stimulated interest in exploration and isolation of microbes from this extreme environment. Enzymes produced by these organisms have a considerable potential for technological applications because they are known to have higher enzymatic activities at lower temperatures than their mesophilic and thermophilic counterparts. A total of 518 Antarctic microorganisms, were isolated during Antarctic expeditions organized by the Instituto Antártico Uruguayo. Samples of particules suspended in air, ice, sea and freshwater, soil, sediment, bird and marine animal faeces, dead animals, algae, plants, rocks and microbial mats were collected from different sites in maritime Antarctica. We report enzymatic activities present in 161 microorganisms (120 bacteria, 31 yeasts and 10 filamentous fungi) isolated from these locations. Enzymatic performance was evaluated at 4 and 20°C. Most of yeasts and bacteria grew better at 20°C than at 4°C, however the opposite was observed with the fungi. Amylase, lipase and protease activities were frequently found in bacterial strains. Yeasts and fungal isolates typically exhibited lipase, celullase and gelatinase activities. Bacterial isolates with highest enzymatic activities were identified by 16S rDNA sequence analysis as Pseudomonas spp., Psychrobacter sp., Arthrobacter spp., Bacillus sp. and Carnobacterium sp. Yeasts and fungal strains, with multiple enzymatic activities, belonged to Cryptococcus victoriae, Trichosporon pullulans and Geomyces pannorum.

  8. Microorganisms and Chemical Pollution

    ERIC Educational Resources Information Center

    Alexander, M.

    1973-01-01

    Discusses the importance of microorganisms in chemical pollution and pollution abatement. Selected chemical pollutants are chosen to illustrate that microorganisms synthesize hazardous substances from reasonably innocuous precursors, while others act as excellent environmental decontaminating agents by removing undesirable natural and synthetic…

  9. Effect of a cold shock on the activity and composition of the communities of ammonium-oxidizing microorganisms in a chestnut soil

    NASA Astrophysics Data System (ADS)

    Cherobaeva, A. S.; Stepanov, A. L.; Kravchenko, I. K.

    2012-05-01

    The simulation of a cold shock was performed in an incubation experiment with soil microcosms by a sharp decrease of the temperature to negative values and the subsequent analysis of the nitrification rate of the ammonium-oxidizing microorganisms. Three procedures of the cold shock effect were selected: long, short-time, and cyclic. A significant decrease of the nitrifying activity was recorded after the long effect, whereas the 8-, 16-, and 24-hour cold shocks did not affect the intensity of nitrification. A cyclic temperature decrease alternating with periods of incubation under high temperatures also did not affect the nitrifying activity of the microorganisms. We suppose that the domination of mesophilic microorganisms with a resistant enzyme system or of psychrophilic and psychrotolerant microorganisms contributes to the preservation of a high nitrification level in soils with frequent alternations of high and low temperatures.

  10. Vibrio psychroerythrus sp. n.: Classification of the Psychrophilic Marine Bacterium, NRC 1004

    PubMed Central

    D'aoust, J. Y.; Kushner, D. J.

    1972-01-01

    A red-pigmented organism, formerly known as marine psychrophile NRC 1004, has been classified as Vibrio psychroerythrus sp. n. Classification was mainly based on morphology, the ability of the organism to oxidize and ferment glucose, its sensitivity to vibriostat 0/129, and its deoxyribonucleic acid base composition of 40.0 moles% guanine plus cytosine, determined by thermal denaturation. The organism gave positive reactions for catalase, oxidase, and starch hydrolysis and produced acid from maltose and dextrin but not from arabinose. It was indole- and citrate-negative and reduced nitrate to nitrite without producing gas. PMID:5053463

  11. Micro-organ device

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); von Gustedt-Gonda, legal representative, Iris (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

    2013-01-01

    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  12. Micro-Organ Device

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

    2013-01-01

    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  13. Structural thermal adaptation of β-tubulins from the Antarctic psychrophilic protozoan Euplotes focardii.

    PubMed

    Chiappori, Federica; Pucciarelli, Sandra; Merelli, Ivan; Ballarini, Patrizia; Miceli, Cristina; Milanesi, Luciano

    2012-04-01

    Tubulin dimers of psychrophilic eukaryotes can polymerize into microtubules at 4°C, a temperature at which microtubules from mesophiles disassemble. This unique capability requires changes in the primary structure and/or in post-translational modifications of the tubulin subunits. To contribute to the understanding of mechanisms responsible for microtubule cold stability, here we present a computational structural analysis based on molecular dynamics (MD) and experimental data of three β-tubulin isotypes, named EFBT2, EFBT3, and EFBT4, from the Antarctic protozoon Euplotes focardii that optimal temperature for growth and reproduction is 4°C. In comparison to the β-tubulin from E. crassus, a mesophilic Euplotes species, EFBT2, EFBT3, and EFBT4 possess unique amino acid substitutions that confer different flexible properties of the polypeptide, as well as an increased hydrophobicity of the regions involved in microtubule interdimeric contacts that may overcome the microtubule destabilizing effect of cold temperatures. The structural analysis based on MD indicated that all isotypes display different flexibility properties in the regions involved in the formation of longitudinal and lateral contacts during microtubule polymerization. We also investigated the role of E. focardii β-tubulin isotypes during the process of cilia formation. The unique characteristics of the primary and tertiary structures of psychrophilic β-tubulin isotypes seem responsible for the formation of microtubules with distinct dynamic and functional properties.

  14. Antarctomyces pellizariae sp. nov., a new, endemic, blue, snow resident psychrophilic ascomycete fungus from Antarctica.

    PubMed

    de Menezes, Graciéle C A; Godinho, Valéria M; Porto, Bárbara A; Gonçalves, Vívian N; Rosa, Luiz H

    2017-03-01

    In the present study, we have identified and characterised a new snow resident ascomycete blue stain fungus from Antarctica named Antarctomyces pellizariae sp. nov. Menezes, Godinho, Porto, Gonçalves and Rosa, using polyphasic taxonomy techniques. This fungal species was recovered from the seasonal snow of the Antarctic Peninsula. Antarctomyces pellizariae displayed different macro- and micromorphology when compared with A. psychrotrophicus Stchigel and Guarro, the only other Antarctomyces species reported until date. Antarctomyces pellizariae showed psychrophilic behavior and very low growth rate at 22-25 °C, quite different from A. psychrotrophicus that has a higher growth rate at mesophilic temperatures. In addition, micromorphological characteristics and the analysis of the nuclear rDNA internal transcribed spacer, β-tubulin, and RNA polymerase II regions revealed that A. pellizariae is a new species that is related to A. psychrotrophicus and Thelebolus species. Since the Antarctic Peninsula is reported to be one of the main regions of the earth experiencing the effects of global change in climate, species, such as A. pellizariae, might provide information about these effects on the endemic Antarctic biota. In addition, A. pellizariae displayed psychrophilic behavior and might be a source of interesting anti-freeze compounds that might prove useful in biotechnological processes.

  15. Enzyme activity determination on macromolecular substrates by isothermal titration calorimetry: application to mesophilic and psychrophilic chitinases.

    PubMed

    Lonhienne, T; Baise, E; Feller, G; Bouriotis, V; Gerday, C

    2001-02-09

    Isothermal titration calorimetry has been applied to the determination of the kinetic parameters of chitinases (EC 3.2.1.14) by monitoring the heat released during the hydrolysis of chitin glycosidic bonds. Experiments were carried out using two different macromolecular substrates: a soluble polymer of N-acetylglucosamine and the insoluble chitin from crab shells. Different experimental temperatures were used in order to compare the thermodependence of the activity of two chitinases from the psychrophile Arthrobacter sp. TAD20 and of chitinase A from the mesophile Serratia marcescens. The method allowed to determine unequivocally the catalytic rate constant k(cat), the activation energy (E(a)) and the thermodynamic activation parameters (DeltaG(#), DeltaH(#), DeltaS(#)) of the chitinolytic reaction on the soluble substrate. The catalytic activity has also been determined on insoluble chitin, which displays an effect of substrate saturation by chitinases. On both substrates, the thermodependence of the activity of the psychrophilic chitinases was lower than that observed with the mesophilic counterpart.

  16. Purification and characterization of cold-adapted beta-agarase from an Antarctic psychrophilic strain

    PubMed Central

    Li, Jiang; Hu, Qiushi; Li, Yuquan; Xu, Yuan

    2015-01-01

    An extracellular β-agarase was purified from Pseudoalteromonas sp. NJ21, a Psychrophilic agar-degrading bacterium isolated from Antarctic Prydz Bay sediments. The purified agarase (Aga21) revealed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular weight of 80 kDa. The optimum pH and temperature of the agarase were 8.0 and 30 °C, respectively. However, it maintained as much as 85% of the maximum activities at 10 °C. Significant activation of the agarase was observed in the presence of Mg2+, Mn2+, K+; Ca2+, Na+, Ba2+, Zn2+, Cu2+, Co2+, Fe2+, Sr2+ and EDTA inhibited the enzyme activity. The enzymatic hydrolyzed product of agar was characterized as neoagarobiose. Furthermore, this work is the first evidence of cold-adapted agarase in Antarctic psychrophilic bacteria and these results indicate the potential for the Antarctic agarase as a catalyst in medicine, food and cosmetic industries. PMID:26413048

  17. INFLUENCE OF MODERATE TEMPERATURE ON GROWTH AND MALIC DEHYDROGENASE ACTIVITY OF A MARINE PSYCHROPHILE.

    PubMed

    MORITA, R Y; BURTON, S D

    1963-11-01

    Morita, Richard Y. (Oregon State University, Corvallis), and Sheril D. Burton. Influence of moderate temperature on growth and malic dehydrogenase activity of a marine psychrophile. J. Bacteriol. 86:1025-1029. 1963.-The maximal and optimal growth temperatures for a marine psychrophilic vibrio (PS 207) were determined to be 30 and 24.5 C, respectively. Malic dehydrogenase was found to be functioning in whole cells at about 1/20 of its observed maximum. Incubation of the cells, prior to or during the assay, at temperatures above the maximal growth temperature permitted the malic dehydrogenase to operate nearer its maximum, but this also inactivated the intracellular enzyme. The heating of whole cells gave an apparent effect of increasing malic dehydrogenase activity. Lysis of the cells permitted the enzyme to function at its full potential but rendered the enzyme more sensitive to heat denaturation. Lysis of the cells also caused the enzyme to lose approximately one-half of its malic dehydrogenase activity with each 10 C drop in temperature, whereas whole cells only lose approximately 1/5 of their enzyme activity at low temperatures with each 10 C drop.

  18. Temperature-Sensitive Salmonella enterica Serovar Enteritidis PT13a Expressing Essential Proteins of Psychrophilic Bacteria

    PubMed Central

    Duplantis, Barry N.; Puckett, Stephanie M.; Rosey, Everett L.; Ameiss, Keith A.; Hartman, Angela D.; Pearce, Stephanie C.

    2015-01-01

    Synthetic genes based on deduced amino acid sequences of the NAD-dependent DNA ligase (ligA) and CTP synthetase (pyrG) of psychrophilic bacteria were substituted for their native homologues in the genome of Salmonella enterica serovar Enteritidis phage type 13a (PT13a). The resulting strains were rendered temperature sensitive (TS) and did not revert to temperature resistance at a detectable level. At permissive temperatures, TS strains grew like the parental strain in broth medium and in macrophage-like cells, but their growth was slowed or stopped when they were shifted to a restrictive temperature. When injected into BALB/c mice at the base of the tail, representing a cool site of the body, the strains with restrictive temperatures of 37, 38.5, and 39°C persisted for less than 1 day, 4 to 7 days, and 20 to 28 days, respectively. The wild-type strain persisted at the site of inoculation for at least 28 days. The wild-type strain, but not the TS strains, was also found in spleen-plus-liver homogenates within 1 day of inoculation of the tail and was detectable in these organs for at least 28 days. Intramuscular vaccination of White Leghorn chickens with the PT13a strain carrying the psychrophilic pyrG gene provided some protection against colonization of the reproductive tract and induced an anti-S. enterica antibody response. PMID:26187965

  19. [Temperature range for growth of the Antarctic microorganisms].

    PubMed

    Romanovaskaia, V A; Tashirev, A B; Gladka, G B; Tashireva, A A

    2012-01-01

    The assessment of a temperature range for growth of microorganisms isolated at various temperatures (1-5 degrees C or 30 degrees C) from biotopes of the Antarctic region (soil, grass Deschampcia antarctica, grass Colobanthus, a green moss, crustose black lichens and encrustation biofilm on vertical rocks) is made. From 40 to 70% of the investigated Antarctic microorganisms, irrespective of temperature conditions of their isolation, were capable of growing in a wide temperature range (from 1 degrees C to 30 degrees C), i.e. they are psychrotolerant. In selective conditions (1 degrees C or 5 degrees C) the psychrophilic Antarctic bacteria and yeast are isolated which grew in the range from 1 degrees C to 20 degrees C and did not grow at 30 degrees C. At the same time, among the Antarctic microorganisms isolated in nonselective conditions (at 30 degrees C), almost 50% are capable of growing at the lowest temperature (5 degrees C), and a smaller number of strains--at 1 degrees C. However with a decrease of cultivation temperature the growth lag-phase of the Antarctic bacteria increased. Thus the level of the final biomass of the investigated strains did not depend on cultivation temperature. When comparing the temperature range of growth of the mesophilic Antarctic bacteria and collection strains of the same species isolated more than 10 years ago from the region with a temperate climate, the psychrotolerant forms were also revealed among the latter. So, it is shown that the investigated Antarctic bacteria can exist in the temperature range characteristic of terrestrial biotopes of the Antarctic Region (from 1 degrees C to 10 degrees C).

  20. Draft genome of Cryobacterium sp. MLB-32, an obligate psychrophile from glacier cryoconite holes of high Arctic.

    PubMed

    Singh, Purnima; Kapse, Neelam; Arora, Preeti; Singh, Shiv Mohan; Dhakephalkar, Prashant K

    2015-06-01

    Obligate psychrophilic, Cryobacterium sp. MLB-32, was isolated from cryoconite holes of high Arctic glaciers. Here, we report the first draft genome sequence of the putative novel species of the genus Cryobacterium, providing opportunities for biotechnological and agricultural exploitation of its genome features.

  1. Fossil Microorganisms in Archaean

    NASA Technical Reports Server (NTRS)

    Astafleva, Marina; Hoover, Richard; Rozanov, Alexei; Vrevskiy, A.

    2006-01-01

    Ancient Archean and Proterozoic rocks are the model objects for investigation of rocks comprising astromaterials. The first of Archean fossil microorganisms from Baltic shield have been reported at the last SPIE Conference in 2005. Since this confeence biomorphic structures have been revealed in Archean rocks of Karelia. It was determined that there are 3 types of such bion structures: 1. structures found in situ, in other words microorganisms even-aged with rock matrix, that is real Archean fossils biomorphic structures, that is to say forms inhabited early formed rocks, and 3. younger than Archean-Protherozoic minerali microorganisms, that is later contamination. We made attempt to differentiate these 3 types of findings and tried to understand of burial of microorganisms. The structures belongs (from our point of view) to the first type, or real Archean, forms were under examination. Practical investigation of ancient microorganisms from Green-Stone-Belt of Northern Karelia turns to be very perspective. It shows that even in such ancient time as Archean ancient diverse world existed. Moreover probably such relatively highly organized cyanobacteria and perhaps eukaryotic formes existed in Archean world.

  2. Microorganism identification technique

    SciTech Connect

    Sillman, R. E.

    1985-07-02

    An identification technique for micro-organisms in which a dilute solution of a culture medium containing an unknown micro-organism has added thereto an emissive agent such as a radioactive amino acid to produce a mix of emissive products that depends on the metabolic mechanism of the micro-organism. After a predetermined incubation period, the reaction is arrested and the solution layered onto a gel plate where it is subjected to electrophoresis. The plate is then autoradiographed by exposing the gel to a sensitive photographic film for a period sufficient to produce thereon a characteristic band pattern functioning as an identifier for the micro-organism. Identification may be effected by comparing the identifier for the unknown with a collection of identifiers for known micro-organisms to find a match with one of these known identifiers. The comparison is preferably carried out by scanning the unknown identifier to produce a signal which is compared with signals representing known identifiers stored in a computer which, when a match is found, yields identification data. Alternatively, the emissive products, after separation, may be detected by direct scanning to provide an identifier signal for computer processing.

  3. Elastohydrodynamics of flagellated microorganisms

    NASA Astrophysics Data System (ADS)

    Li, Gaojin; Ardekani, Arezoo

    2016-11-01

    The swimming motion of many microorganisms and cells are achieved by the waving deformation of their cilia and flagella. The typical structure of flagella and cilia contains nine doublets of parallel microtubules in a cylindrical arrangement surrounding one pair of microtubules in the center. The dynein molecular motors internally drive the sliding motion between the neighboring microtubules and cause the bending motion of the flagella and cilia and drive the microorganism swimming motion. In this work, we develop a numerical model for a microorganism swimming by an internally self-driven filament. Our numerical method captures the interaction between the elasticity of the flagellum and the surround fluid. The no-slip boundary conditions are satisfied by an iterative distributed Lagrangian multiplier method. We also investigate the effects of the non-Newtonian fluid rheology on the motion of an elastic flagellum near a wall.

  4. Micro-Organ Devices

    NASA Technical Reports Server (NTRS)

    Gonda, Steven R.; Leslie, Julia; Chang, Robert C.; Starly, Binil; Sun, Wei; Culbertson, Christopher; Holtorf, Heidi

    2009-01-01

    Micro-organ devices (MODs) are being developed to satisfy an emerging need for small, lightweight, reproducible, biological-experimentati on apparatuses that are amenable to automated operation and that imp ose minimal demands for resources (principally, power and fluids). I n simplest terms, a MOD is a microfluidic device containing a variety of microstructures and assemblies of cells, all designed to mimic a complex in vivo microenvironment by replicating one or more in vivo micro-organ structures, the architectures and composition of the extr acellular matrices in the organs of interest, and the in vivo fluid flows. In addition to microscopic flow channels, a MOD contains one or more micro-organ wells containing cells residing in microscopic e xtracellular matrices and/or scaffolds, the shapes and compositions o f which enable replication of the corresponding in vivo cell assembl ies and flows.

  5. Microorganisms and Man.

    ERIC Educational Resources Information Center

    Noble, W. C.

    1983-01-01

    Provides information to update Institute of Biology's Studies in Biology No. 111, "Microorganisms and Man," by W. C. Noble and Jay Naidoo (Edward Arnold, 1979). Topics include: (1) food poisoning; (2) airborn infections in man; (3) infection in animals and plants; and (4) biodegradation and biosynthesis. (JN)

  6. [Biotechnology using modified microorganisms].

    PubMed

    Deshayes, A F

    1992-11-01

    Few microorganisms, as compare to their high diversity, are used for human needs. They can produce molecules of interest, process fermentation, protect crops, treat wastes or clean environment. Molecular technics and genetic engineering are new tools offer to geneticists which breed microorganisms for years. Using them, it is now possible, theoretically, to introduce any gene in any organism. Some examples are given concerning genetic modifications in yeasts and lactic acid bacteria to optimize agrofood processes and to improve nutritive and flavour characteristics of fermented products like bread, beer, wine, cheese, meat, vegetable juices... In spite of scientific and industrial interest of the new technologies, limiting factors can explain that genetically modified microorganisms are not routinely used in agrofood yet. First, risks assessment on human health and environment are still in debate, but their is a consensus, within the scientific community, to consider that new characteristics of improved microorganisms are more important than the technics used for their construction. Second, regulations turn out to impose constraints susceptible to discourage technological innovations. At least, the public perception about the new technologies appears, actually, as the major factor to limit their development.

  7. In silico analysis of the thermodynamic stability changes of psychrophilic and mesophilic alpha-amylases upon exhaustive single-site mutations.

    PubMed

    Gilis, Dimitri

    2006-01-01

    Identifying sequence modifications that distinguish psychrophilic from mesophilic proteins is important for designing enzymes with different thermodynamic stabilities and to understand the underlying mechanisms. The PoPMuSiC algorithm is used to introduce, in silico, all the single-site mutations in four mesophilic and one psychrophilic chloride-dependent alpha-amylases and to evaluate the changes in thermodynamic stability. The analysis of the distribution of the sequence positions that could be stabilized upon mutation shows a clear difference between the three domains of psychrophilic and mesophilic alpha-amylases. Most of the mutations stabilizing the psychrophilic enzyme are found in domains B and C, contrary to the mesophilic proteins where they are preferentially situated in the catalytic domain A. Moreover, the calculations show that the environment of some residues responsible for the activity of the psychrophilic protein has evolved to reinforce favorable interactions with these residues. In the second part, these results are exploited to propose rationally designed mutations that are predicted to confer to the psychrophilic enzyme mesophilic-like thermodynamic properties. Interestingly, most of the mutations found in domain C strengthen the interactions with domain A, in agreement with suggestions made on the basis of structural analyses. Although this study focuses on single-site mutations, the thermodynamic effects of the recommended mutations should be additive if the mutated residues are not close in space.

  8. Isolation and characterization of marine psychrophilic phage-host systems from Arctic sea ice.

    PubMed

    Borriss, Michael; Helmke, Elisabeth; Hanschke, Renate; Schweder, Thomas

    2003-10-01

    Phage-host systems from extreme cold environments have rarely been surveyed. This study is concerned with the isolation and characterization of three different phage-host systems from Arctic sea ice and melt pond samples collected north-west of Svalbard (Arctic). On the basis of 16S rDNA sequences, the three bacterial phage hosts exhibited the greatest similarity to the species Shewanella frigidimarina (96.0%), Flavobacterium hibernum (94.0%), and Colwellia psychrerythraea (98.4%), respectively. The host bacteria are psychrophilic with good growth at 0 degrees C, resulting in a rapid formation of visible colonies at this temperature. The phages showed an even more pronounced adaptation to cold temperatures than the bacteria, with growth maxima below 14 degrees C and good plaque formation at 0 degrees C. Transmission electron microscopy (TEM) examinations revealed that the bacteriophages belonged to the tailed, double-stranded DNA phage families Siphoviridae and Myoviridae. All three phages were host-specific.

  9. Evidence for the existence of psychrophilic methanogenic communities in anoxic sediments of deep lakes.

    PubMed

    Nozhevnikova, Alla N; Zepp, Kornelia; Vazquez, Francisco; Zehnder, Alexander J B; Holliger, Christof

    2003-03-01

    In order to obtain evidence for the existence of psychrophilic methanogenic communities in sediments of deep lakes that are low-temperature environments (4 to 5 degrees C), slurries were first incubated at temperatures between 4 and 60 degrees C for several weeks, at which time they were amended, or not, with an additional substrate, such as cellulose, butyrate, propionate, acetate, or hydrogen, and further incubated at 6 degrees C. Initial methane production rates were highest in slurries preincubated at temperatures between 4 and 15 degrees C, with maximal rates in slurries kept at 6 degrees C. Hydrogen-amended cultures were the only exceptions, with the highest methane production rates at 6 degrees C after preincubation at 30 degrees C.

  10. Temperature adaptations in psychrophilic, mesophilic and thermophilic chloride-dependent alpha-amylases.

    PubMed

    Cipolla, Alexandre; Delbrassine, François; Da Lage, Jean-Luc; Feller, Georges

    2012-09-01

    The functional and structural adaptations to temperature have been addressed in homologous chloride-dependent α-amylases from a psychrophilic Antarctic bacterium, the ectothermic fruit fly, the homeothermic pig and from a thermophilic actinomycete. This series covers nearly all temperatures encountered by living organisms. We report a striking continuum in the functional properties of these enzymes coupled to their structural stability and related to the thermal regime of the source organism. In particular, thermal stability recorded by intrinsic fluorescence, circular dichroism and differential scanning calorimetry appears to be a compromise between the requirement for a stable native state and the proper structural dynamics to sustain the function at the environmental/physiological temperatures. The thermodependence of activity, the kinetic parameters, the activations parameters and fluorescence quenching support these activity-stability relationships in the investigated α-amylases.

  11. Identification of miniature plasmids in psychrophilic Arctic bacteria of the genus Variovorax.

    PubMed

    Ciok, Anna; Dziewit, Lukasz; Grzesiak, Jakub; Budzik, Karol; Gorniak, Dorota; Zdanowski, Marek K; Bartosik, Dariusz

    2016-04-01

    The Svalbard archipelago (Spitsbergen Island) is the northernmost landmass in the European Arctic and has a variety of small- and medium-sized glaciers. The plasmidome of eleven psychrophilic strains of Variovorax spp. isolated from the ice surface of Hans and Werenskiold Glaciers of Spitsbergen Island, was defined. This analysis revealed the presence of six plasmids whose nucleotide sequences have been determined. Four of them, exhibiting high reciprocal sequence similarity, possess unique structures, since their genomes lack any recognized genes. These miniature replicons, not exceeding 1 kb in size, include pHW69V1 (746 bp), which is the smallest autonomous replicon so far identified in free-living bacteria. The miniature plasmids share no similarity with known sequences present in the databases. In silico and experimental analyses identified conserved DNA regions essential for the initiation of replication of these replicons.

  12. Paenibacillus tibetensis sp. nov., a psychrophilic bacterium isolated from alpine swamp meadow soil.

    PubMed

    Han, Li-Li; He, Ji-Zheng; Zheng, Yuan-Ming; Zeng, Jun; Zhang, Li-Mei

    2015-05-01

    A novel psychrophilic strain, SSB001(T), was isolated from an alpine swamp meadow soil in Tibet, China, and identified as a representative of a novel phylogenetic subclade in the genus Paenibacillus , with Paenibacillus antarcticus (96.2%), Paenibacillus macquariensis (96.53%) and Paenibacillus glacialis (96.2%) as the most closely related species on the basis of 16S rRNA gene sequence analyses. The strain was distinguished from defined species of the genus Paenibacillus by further study of rpoB gene sequences, phenotypic characterization, cellular fatty acid composition, quinones, polar lipids and meso-diaminopimelic acid in the peptidoglycan. Based upon these results, we propose the strain as a representative of a novel species named Paenibacillus tibetensis sp. nov., with SSB001(T) ( =ACCC 19728(T) =DSM 29321(T)) as the type strain. The DNA G+C content (mol%) of strain SSB001(T) was 40.18 mol% (HPLC).

  13. Toward understanding life under subzero conditions: the significance of exploring psychrophilic "cold-shock" proteins.

    PubMed

    Kuhn, Emanuele

    2012-11-01

    Understanding the behavior of proteins under freezing conditions is vital for detecting and locating extraterrestrial life in cold environments, such as those found on Mars and the icy moons of Jupiter and Saturn. This review highlights the importance of studying psychrophilic "cold-shock" proteins, a topic that has yet to be explored. A strategy for analyzing the psychrophilic RNA helicase protein CsdA (Psyc_1082) from Psychrobacter arcticus 273-4 as a key protein for life under freezing temperatures is proposed. The experimental model presented here was developed based on previous data from investigations of Escherichia coli, P. arcticus 273-4, and RNA helicases. P. arcticus 273-4 is considered a model for life in freezing environments. It is capable of growing in temperatures as cold as -10°C by using physiological strategies to survive not only in freezing temperatures but also under low-water-activity and limited-nutrient-availability conditions. The analyses of its genome, transcriptome, and proteome revealed specific adaptations that allow it to inhabit freezing environments by adopting a slow metabolic strategy rather than a cellular dormancy state. During growth at subzero temperatures, P. arcticus 273-4 genes related to energy metabolism and carbon substrate incorporation are downregulated, and genes for maintenance of membranes, cell walls, and nucleic acid motion are upregulated. At -6°C, P. arcticus 273-4 does not upregulate the expression of either RNA or protein chaperones; however, it upregulates the expression of its cold-shock induced DEAD-box RNA helicase protein A (CsdA - Psyc_1082). CsdA - Psyc_1082 was investigated as a key helper protein for sustaining life in subzero conditions. Proving CsdA - Psyc_1082 to be functional as a key protein for life under freezing temperatures may extend the known minimum growth temperature of a mesophilic cell and provide key information about the mechanisms that underlie cold-induced biological systems in

  14. Psychrophilic dry anaerobic digestion of dairy cow feces: Long-term operation

    SciTech Connect

    Massé, Daniel I. Cata Saady, Noori M.

    2015-02-15

    Highlights: • Psychrophilic dry anaerobic digestion (PDAD) of cow feces (CF) is feasible. • PDAD of CF is as efficient as mesophilic and thermophilic AD at TCL 21 days. • CF (13–16% TS at OLR 5.0 g TCOD{sub fed} kg{sup −1} inoculum d{sup −1}) yielded 222 ± 27 {sub N}L CH{sub 4} kg{sup −1} VS fed. - Abstract: This paper reports experimental results which demonstrate psychrophilic dry anaerobic digestion of cow feces during long-term operation in sequence batch reactor. Cow feces (13–16% total solids) has been anaerobically digested in 12 successive cycles (252 days) at 21 days treatment cycle length (TCL) and temperature of 20 °C using psychrotrophic anaerobic mixed culture. An average specific methane yield (SMY) of 184.9 ± 24.0, 189.9 ± 27.3, and 222 ± 27.7 {sub N}L CH{sub 4} kg{sup −1} of VS fed has been achieved at an organic loading rate of 3.0, 4.0, and 5.0 g TCOD kg{sup −1} inoculum d{sup −1} and TCL of 21 days, respectively. The corresponding substrate to inoculum ratio (SIR) was 0.39 ± 0.06, 0.48 ± .02, 0.53 ± 0.05, respectively. Average methane production rate of 10 ± 1.4 {sub N}L CH{sub 4} kg{sup −1} VS fed d{sup −1} has been obtained. The low concentration of volatile fatty acids indicated that hydrolysis was the reaction limiting step.

  15. Environmentally relevant microorganisms.

    PubMed

    Watanabe, K; Baker, P W

    2000-01-01

    The development of molecular microbial ecology in the 1990s has allowed scientists to realize that microbial populations in the natural environment are much more diverse than microorganisms so far isolated in the laboratory. This finding has exerted a significant impact on environmental biotechnology, since knowledge in this field has been largely dependent on studies with pollutant-degrading bacteria isolated by conventional culture methods. Researchers have thus started to use molecular ecological methods to analyze microbial populations relevant to pollutant degradation in the environment (called environmentally relevant microorganisms, ERMs), although further effort is needed to gain practical benefits from these studies. This review highlights the utility and limitations of molecular ecological methods for understanding and advancing environmental biotechnology processes. The importance of the combined use of molecular ecological and physiological methods for identifying ERMs is stressed.

  16. Microorganisms and psoriasis.

    PubMed Central

    Rosenberg, E. W.; Noah, P. W.; Skinner, R. B.

    1994-01-01

    It has been suggested previously that psoriasis is best explained as a distinctive inflammatory response to a variety of microbial stimuli, all acting primarily through activation of the alternative complement pathway. For the past several years we have conducted a "Problem Psoriasis Clinic" based on that premise. Patients are questioned, examined, and subjected to microbiologic laboratory investigations in an attempt to identify possibly relevant microorganisms, and then are treated with antibiotics. This article lists the most commonly found microorganisms in psoriasis patients and describes the usual treatment for each. Results obtained with this approach compare favorably with those achieved with more usual anti-psoriasis treatments. We recommend that a microbiologic investigation and a trial of antimicrobial treatment should precede any plan to treat psoriasis patients with anything more than the simplest topical agents. PMID:8040907

  17. Inactivation of Microorganisms

    NASA Astrophysics Data System (ADS)

    Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

    Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

  18. Temperature Sensitivity Conferred by ligA Alleles from Psychrophilic Bacteria upon Substitution in Mesophilic Bacteria and a Yeast Species

    PubMed Central

    Pankowski, Jarosław A.; Puckett, Stephanie M.

    2016-01-01

    We have assembled a collection of 13 psychrophilic ligA alleles that can serve as genetic elements for engineering mesophiles to a temperature-sensitive (TS) phenotype. When these ligA alleles were substituted into Francisella novicida, they conferred a TS phenotype with restrictive temperatures between 33 and 39°C. When the F. novicida ligA hybrid strains were plated above their restrictive temperatures, eight of them generated temperature-resistant variants. For two alleles, the mutations that led to temperature resistance clustered near the 5′ end of the gene, and the mutations increased the predicted strength of the ribosome binding site at least 3-fold. Four F. novicida ligA hybrid strains generated no temperature-resistant variants at a detectable level. These results suggest that multiple mutations are needed to create temperature-resistant variants of these ligA gene products. One ligA allele was isolated from a Colwellia species that has a maximal growth temperature of 12°C, and this allele supported growth of F. novicida only as a hybrid between the psychrophilic and the F. novicida ligA genes. However, the full psychrophilic gene alone supported the growth of Salmonella enterica, imparting a restrictive temperature of 27°C. We also tested two ligA alleles from two Pseudoalteromonas strains for their ability to support the viability of a Saccharomyces cerevisiae strain that lacked its essential gene, CDC9, encoding an ATP-dependent DNA ligase. In both cases, the psychrophilic bacterial alleles supported yeast viability and their expression generated TS phenotypes. This collection of ligA alleles should be useful in engineering bacteria, and possibly eukaryotic microbes, to predictable TS phenotypes. PMID:26773080

  19. Detecting the presence of microorganisms

    NASA Technical Reports Server (NTRS)

    Wilkins, Judd R. (Inventor); Stoner, Glenn E. (Inventor)

    1977-01-01

    The presence of microorganisms in a sample is determined by culturing microorganisms in a growth medium which is in contact with a measuring electrode and a reference electrode and detecting a change in potential between the electrodes caused by the presence of the microorganisms in the medium with a high impedance potentiometer.

  20. Detection of psychrophilic and psychrotolerant Clostridium spp. in chilled fresh vacuum-packed meat using different PCR methods.

    PubMed

    Bonke, R; Drees, N; Gareis, M

    2016-01-01

    Since 1989, blown pack spoilage has been recognized as a special form of spoilage in vacuum-packed raw and cooked beef. However, only limited information concerning the occurrences of bacteria causing blown pack spoilage on chilled fresh meat is available. In this study, a total of 63 beef and 33 lamb commercially available samples from different countries and without any signs of spoilage were examined for contamination with psychrophilic and psychrotolerant Clostridium spp. using different PCR systems. In total, 34.4% of the chilled fresh vacuum-packed meats were PCR positive. A higher number of lamb samples were identified as PCR positive compared with beef. A geographical relationship between positive results and the origin of the samples could not be determined. PCR system described by Brightwell and Clemens (Development and validation of a real-time PCR assay specific for Clostridium estertheticum and C. estertheticum-like psychrotolerant bacteria. Meat Sci 2012;92:697-703) gave the highest number of positive detections compared with the Broda, Boerema and Bell PCR system (PCR detection of psychrophilic Clostridium spp. causing 'blown pack' spoilage of vacuum-packed chilled meats. J Appl Microbiol 2003;94:515-22). Eight clostridia isolates from two German beef and four Welsh lamb samples were isolated overall. Three of these clostridia isolates were identified as Clostridium estertheticum whereas five clostridia isolates remain unidentified. The study shows that psychrophilic and psychrotolerant Clostridium spp. are more prevalent in retail samples than previously suspected.

  1. Genomic, Transcriptomic, and Proteomic Analysis Provide Insights Into the Cold Adaptation Mechanism of the Obligate Psychrophilic Fungus Mrakia psychrophila

    PubMed Central

    Su, Yao; Jiang, Xianzhi; Wu, Wenping; Wang, Manman; Hamid, M. Imran; Xiang, Meichun; Liu, Xingzhong

    2016-01-01

    Mrakia psychrophila is an obligate psychrophilic fungus. The cold adaptation mechanism of psychrophilic fungi remains unknown. Comparative genomics analysis indicated that M. psychrophila had a specific codon usage preference, especially for codons of Gly and Arg and its major facilitator superfamily (MFS) transporter gene family was expanded. Transcriptomic analysis revealed that genes involved in ribosome and energy metabolism were upregulated at 4°, while genes involved in unfolded protein binding, protein processing in the endoplasmic reticulum, proteasome, spliceosome, and mRNA surveillance were upregulated at 20°. In addition, genes related to unfolded protein binding were alternatively spliced. Consistent with other psychrophiles, desaturase and glycerol 3-phosphate dehydrogenase, which are involved in biosynthesis of unsaturated fatty acid and glycerol respectively, were upregulated at 4°. Cold adaptation of M. psychrophila is mediated by synthesizing unsaturated fatty acids to maintain membrane fluidity and accumulating glycerol as a cryoprotectant. The proteomic analysis indicated that the correlations between the dynamic patterns between transcript level changes and protein level changes for some pathways were positive at 4°, but negative at 20°. The death of M. psychrophila above 20° might be caused by an unfolded protein response. PMID:27633791

  2. Microorganisms for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  3. Systems biology of industrial microorganisms.

    PubMed

    Papini, Marta; Salazar, Margarita; Nielsen, Jens

    2010-01-01

    The field of industrial biotechnology is expanding rapidly as the chemical industry is looking towards more sustainable production of chemicals that can be used as fuels or building blocks for production of solvents and materials. In connection with the development of sustainable bioprocesses, it is a major challenge to design and develop efficient cell factories that can ensure cost efficient conversion of the raw material into the chemical of interest. This is achieved through metabolic engineering, where the metabolism of the cell factory is engineered such that there is an efficient conversion of sugars, the typical raw materials in the fermentation industry, into the desired product. However, engineering of cellular metabolism is often challenging due to the complex regulation that has evolved in connection with adaptation of the different microorganisms to their ecological niches. In order to map these regulatory structures and further de-regulate them, as well as identify ingenious metabolic engineering strategies that full-fill mass balance constraints, tools from systems biology can be applied. This involves both high-throughput analysis tools like transcriptome, proteome and metabolome analysis, as well as the use of mathematical modeling to simulate the phenotypes resulting from the different metabolic engineering strategies. It is in fact expected that systems biology may substantially improve the process of cell factory development, and we therefore propose the term Industrial Systems Biology for how systems biology will enhance the development of industrial biotechnology for sustainable chemical production.

  4. Systems Biology of Industrial Microorganisms

    NASA Astrophysics Data System (ADS)

    Papini, Marta; Salazar, Margarita; Nielsen, Jens

    The field of industrial biotechnology is expanding rapidly as the chemical industry is looking towards more sustainable production of chemicals that can be used as fuels or building blocks for production of solvents and materials. In connection with the development of sustainable bioprocesses, it is a major challenge to design and develop efficient cell factories that can ensure cost efficient conversion of the raw material into the chemical of interest. This is achieved through metabolic engineering, where the metabolism of the cell factory is engineered such that there is an efficient conversion of sugars, the typical raw materials in the fermentation industry, into the desired product. However, engineering of cellular metabolism is often challenging due to the complex regulation that has evolved in connection with adaptation of the different microorganisms to their ecological niches. In order to map these regulatory structures and further de-regulate them, as well as identify ingenious metabolic engineering strategies that full-fill mass balance constraints, tools from systems biology can be applied. This involves both high-throughput analysis tools like transcriptome, proteome and metabolome analysis, as well as the use of mathematical modeling to simulate the phenotypes resulting from the different metabolic engineering strategies. It is in fact expected that systems biology may substantially improve the process of cell factory development, and we therefore propose the term Industrial Systems Biology for how systems biology will enhance the development of industrial biotechnology for sustainable chemical production.

  5. Structural prediction and comparative docking studies of psychrophilic β- Galactosidase with lactose, ONPG and PNPG against its counter parts of mesophilic and thermophilic enzymes.

    PubMed

    Kumar, Ponnada Suresh; Pulicherla, Kk; Ghosh, Mrinmoy; Kumar, Anmol; Rao, Krs Sambasiva

    2011-01-01

    Enzymes from psychrophiles catalyze the reactions at low temperatures with higher specific activity. Among all the psychrophilic enzymes produced, cold active β-galactosidase from marine psychrophiles revalorizes a new arena in numerous areas at industrial level. The hydrolysis of lactose in to glucose and galactose by cold active β-galactosidase offers a new promising approach in removal of lactose from milk to overcome the problem of lactose intolerance. Herein we propose, a 3D structure of cold active β-galactosidase enzyme sourced from Pseudoalteromonas haloplanktis by using Modeler 9v8 and best model was developed having 88% of favourable region in ramachandran plot. Modelling was followed by docking studies with the help of Auto dock 4.0 against the three substrates lactose, ONPG and PNPG. In addition, comparative docking studies were also performed for the 3D model of psychrophilic β-galactosidase with mesophilic and thermophilic enzymes. Docking studies revealed that binding affinity of enzyme towards the three different substrates is more for psychrophilic enzyme when compared with mesophilic and thermophilic enzymes. It indicates that the enzyme has high specific activity at low temperature when compared with mesophilic and thermophilic enzymes.

  6. Effect of temperature on the shift of Pseudomonas fluorescens from an environmental microorganism to a potential human pathogen.

    PubMed

    Donnarumma, G; Buommino, E; Fusco, A; Paoletti, I; Auricchio, L; Tufano, M A

    2010-01-01

    Pseudomonas fluorescens is a Gram-negative bacterium generally considered of scarce clinical significance. However, in the last few years, the isolation of P. fluorescens as the causative agent of nosocomial infections has rapidly increased. P. fluorescens is a psychrophile microorganism which grows at an optimal temperature of 25-30 degrees Celcius. In spite of this constraint, it has recently been reported that the human physiological temperature does not appear to be a barrier for this microorganism. In this study we examined the ability of P. fluorescens, grown at 28 degrees C or at 37 degrees C, to adhere to cultured human A549 pulmonary cells and to form biofilm. The ability of P. fluorescens to induce expression of proinflammatory cytokines, beta-defensin 2 and the intercellular adhesion molecule-1 was also investigated. Our results clearly indicate that inflammatory mediators are induced when the microorganism is grown at a lower temperature, while biofilm is formed only at 37 degrees C. The results presented are consistent with previous reports indicating P. fluorescens as an opportunistic pathogen and underscore the urgent need for further studies to better characterize the virulence of this microorganism.

  7. Massilia eurypsychrophila sp. nov. a facultatively psychrophilic bacteria isolated from ice core.

    PubMed

    Shen, Liang; Liu, Yongqin; Gu, Zhengquan; Xu, Baiqing; Wang, Ninglian; Jiao, Nianzhi; Liu, Hongcan; Zhou, Yuguang

    2015-07-01

    Strain B528-3(T), a Gram-stain-negative, rod-shaped, aerobic, facultatively psychrophilic bacterium with polar flagella, was isolated from an ice core drilled from Muztagh Glacier, Xinjiang, China. The novel isolate was classified into the genus Massilia. The 16S rRNA gene sequence of the novel isolate shares a pairwise similarity of less than 97% with those of all the type strains of the genus Massilia. The major fatty acids of strain B528-3(T) were summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH) (57.31%), C16:0 (11.46%) and C18:1ω7c (14.72%). The predominant isoprenoid quinone was Q-8. The DNA G + C content was 62.2 mol% (Tm). The major polar lipids of this bacterium were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. From the genotypic and phenotypic data, it is evident that strain B528-3(T) represents a novel species of the genus Massilia, for which the name Massilia eurypsychrophila sp. nov. is proposed. The type strain is B528-3(T) ( = JCM 30074(T) = CGMCC 1.12828(T)).

  8. Marinobacter psychrophilus sp. nov., a psychrophilic bacterium isolated from the Arctic.

    PubMed

    Zhang, De-Chao; Li, Hui-Rong; Xin, Yu-Hua; Chi, Zhen-Ming; Zhou, Pei-Jin; Yu, Yong

    2008-06-01

    Strain 20041(T) was isolated from sea-ice of the Canadian Basin (7 degrees 23' 14'' N 14 degrees 06' 55'' W). Phylogenetic analysis based on 16S rRNA gene homology showed that strain 20041(T) was related to members of the genus Marinobacter and had highest 16S rRNA gene sequence similarity with the type strain of Marinobacter maritimus. Cells were Gram-negative, rod-shaped, psychrophilic and motile. The temperature range for growth was 0-22 degrees C, with optimum growth occurring at 16-18 degrees C and at approximately pH 6.0-9.0. Strain 20041(T) had ubiquinone-9 as the major respiratory quinone and iso-C(15 : 0) 2OH and/or C(16 : 1)omega7c, C(16 : 0), C(18 : 1)omega9c and C(12 : 0) 3OH as major fatty acids. The genomic DNA G+C content was 55.4 mol%. On the basis of the phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain 20041(T) is considered to represent a novel species, for which the name Marinobacter psychrophilus sp. nov. is proposed. The type strain is 20041(T) (=CGMCC 1.6499(T)=JCM 14643(T)).

  9. Moritella dasanensis sp. nov., a psychrophilic bacterium isolated from the Arctic ocean.

    PubMed

    Kim, Hak Jun; Park, Soyoung; Lee, Jung Min; Park, Seungil; Jung, Woongsic; Kang, Jae-Shin; Joo, Hyung Min; Seo, Ki-Won; Kang, Sung-Ho

    2008-04-01

    An aerobic, motile, Gram-negative, ice-active substance-producing, rod-shaped psychrophile, designated strain ArB 0140T, was isolated from seawater collected from near a glacier in Kongsfjorden, Svalbard Archipelago, Norway. Phylogenetic analysis using 16S rRNA gene sequences indicated that strain ArB 0140T showed a distinct phyletic line within the genus Moritella. Characteristic chemotaxonomic data [predominant isoprenoid quinone, Q8; major fatty acids, C14 : 0, C14 : 1, C16 : 0, C16 : 1 and C22 : 6 (docosahexaenoic acid; DHA)] also corroborated the affiliation of strain ArB 0140T to the genus Moritella. The maximal growth rate of the novel strain was observed at 9 degrees C, with a maximum temperature for growth of 18 degrees C. The genomic DNA G+C content was 46.9 mol%. Based on the data obtained from this polyphasic study, including DNA-DNA relatedness, physiological and biochemical tests and ice-controlling activity, strain ArB 0140T was found to be genetically and phenotypically different from other recognized species of the genus Moritella. Therefore strain ArB 0140T represents a novel species, for which the name Moritella dasanensis sp. nov. is proposed. The type strain is ArB 0140T (=KCTC 10814T=KCCM 42845T=JCM 14759T).

  10. An extracellular ice-binding glycoprotein from an Arctic psychrophilic yeast.

    PubMed

    Lee, Jong Kyu; Park, Kyoung Sun; Park, Seungil; Park, Hyun; Song, Young Hwan; Kang, Sung-Ho; Kim, Hak Jun

    2010-04-01

    A psychrophilic yeast was isolated from an Arctic pond and its culture supernatant showed ice-binding activity. This isolate, identified as Leucosporidium sp. based on an analysis of the D1/D2 and ITS regions of its ribosomal DNA, produced a secretory ice-binding protein (IBP). Yeast IBP was purified from the culture medium to near homogeneity by the ice affinity method and appeared to be glycosylated with a molecular mass of approximately 26 kDa. In addition, the yeast IBP was shown to have thermal hysteresis (TH) and recrystallization inhibition (RI) activities. The full-length cDNA for yeast IBP was determined and was found to encode a 261 amino acid protein with molecular weight of 26.8 kDa that includes an N-terminal signal peptide and one potential N-glycosylation site. The deduced protein showed high sequence identity with other IBPs and hypothetical IBPs from fungi, diatoms, and bacteria, clustering with a class of ice-active proteins.

  11. Sporosarcina antarctica sp. nov., a psychrophilic bacterium isolated from the Antarctic.

    PubMed

    Yu, Yong; Xin, Yu-Hua; Liu, Hong-Can; Chen, Bo; Sheng, Jun; Chi, Zhen-Ming; Zhou, Pei-Jin; Zhang, De-Chao

    2008-09-01

    A Gram-positive, psychrophilic, rod-shaped bacterium, designated strain N-05(T), was isolated from soil samples collected off King George Island, west Antarctica (6 degrees 13' 31'' S 5 degrees 57' 08'' W). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain N-05(T) was related to members of the genus Sporosarcina and had highest 16S rRNA gene sequence similarity with the type strain of Sporosarcina macmurdoensis (98.0%). The temperature range for growth of strain N-05(T) was 0-23 degrees C, with optimum growth occurring at 17-18 degrees C and approximately pH 6.0-8.0. Strain N-05(T) had MK-7 as the major menaquinone and anteiso-C(15:0) and C(16:1)omega7c alcohol as major fatty acids. The genomic DNA G+C content was 39.2 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain N-05(T) is considered to represent a novel species of the genus Sporosarcina, for which the name Sporosarcina antarctica is proposed. The type strain is N-05(T) (=CGMCC 1.6503(T)=JCM 14646(T)).

  12. Cryobacterium levicorallinum sp. nov., a psychrophilic bacterium isolated from glacier ice.

    PubMed

    Liu, Qing; Liu, Hongcan; Zhang, Jianli; Zhou, Yuguang; Xin, Yuhua

    2013-08-01

    In this study, two psychrophilic bacterial strains were isolated from the China No. 1 glacier in Xinjiang, north-west China. Cells were Gram-positive rods. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strains belonged to the genus Cryobacterium. Phylogenetic analysis showed that they clustered together and are most closely related to Cryobacterium luteum CGMCC 1.11210(T), Cryobacterium flavum CGMCC 1.11215(T), Cryobacterium psychrophilum CGMCC 1.4292(T), Cryobacterium psychrotolerans CGMCC 1.5382(T) and Cryobacterium roopkundense CGMCC 1.10672(T). The major cellular fatty acids of the novel strains were anteiso-C15 : 0, anteiso-C15 : 1 A, iso-C16 : 0 and iso-C15 : 0. Both strains contained diphosphatidylglycerol, phosphatidylglycerol and one unidentified glycolipid in the cell membrane. The results of DNA-DNA hybridization and physiological tests allowed the genotypic and phenotypic differentiation of strains Hh34(T) and Hh28 from related species. However, their high DNA-DNA relatedness showed that they belong to the same novel species. Strain Hh34(T) (= NBRC 107883(T) = CGMCC 1.11211(T)) was selected as the type strain to represent this novel species, for which the name Cryobacterium levicorallinum sp. nov. is proposed.

  13. Expression, purification, and characterization of cold-adapted inorganic pyrophosphatase from psychrophilic Shewanella sp. AS-11.

    PubMed

    Ginting, Elvy Like; Iwasaki, Syouhei; Maeganeku, Chihiro; Motoshima, Hiroyuki; Watanabe, Keiichi

    2014-01-01

    In the presence of divalent cations, inorganic pyrophosphatase is activated to hydrolyze inorganic pyrophosphate to inorganic phosphate. Here, we clone, express, purify, and characterize inorganic pyrophosphatase from the psychrophilic Shewanella sp. AS-11 (Sh-PPase). The recombinant Sh-PPase was expressed in Escherichia coli BL21 (DE3) at 20°C using pET16b as an expression vector and purified from the cell extracts by a combination of ammonium sulfate fractionation and anion-exchange chromatography. Sh-PPase was found to be a family II PPase with a subunit molecular mass of 34 kD that preferentially utilizes Mn²⁺ over Mg²⁺ ions for activity. The functional characteristics of Sh-PPase, such as activity, temperature dependency, and thermal inactivation, were greatly influenced by manganese ions. Manganese ion activation increased the enzyme's activity at low temperatures; therefore, it was required to gain the cold-adapted characteristics of Sh-PPase.

  14. Survival of a Psychrophilic Marine Vibrio Under Long-Term Nutrient Starvation 1

    PubMed Central

    Novitsky, James A.; Morita, Richard Y.

    1977-01-01

    Ant-300, a psychrophilic marine vibrio isolated from the surface water of the Antarctic convergence, was starved for periods of more than 1 year. During the first week of starvation, cell numbers increased from 100 to 800% of the initial number of cells. Fifty percent of the starved cells remained viable for 6 to 7 weeks while a portion of the population remained viable for more than 1 year. During the first 2 days of starvation, the endogenous respiration of the cells decreased over 80%. After 7 days, respiration had been reduced to 0.0071% total carbon respired per hour and remained constant thereafter. After 6 weeks of starvation, 46% of the cellular deoxyribonucleic acid had been degraded. Observation of the cellular deoxyribonucleic acid with Feulgen staining before starvation showed the average number of nuclear bodies per cell varied from 1.44 to 4.02 depending on the age of the culture. A linear relationship was found between the number of nuclear bodies per cell and the increase in cell numbers upon starvation. Our data suggest that Ant-300 is capable of surviving long periods of time with little or no nutrients and is therefore well adapted for the sparse nutrient conditions of the colder portions of the open ocean. PMID:16345219

  15. Rhodoferax antarcticus sp. nov., a moderately psychrophilic purple nonsulfur bacterium isolated from an Antarctic microbial mat

    NASA Technical Reports Server (NTRS)

    Madigan, M. T.; Jung, D. O.; Woese, C. R.; Achenbach, L. A.

    2000-01-01

    A new species of purple nonsulfur bacteria isolated from an Antarctic microbial mat is described. The organism, designated strain ANT.BR, was mildly psychrophilic, growing optimally at 15-18 degrees C with a growth temperature range of 0-25 degrees C. Cells of strain ANT.BR were highly motile curved rods and spirals, contained bacteriochlorophyll a, and showed a multicomponent in vivo absorption spectrum. A specific phylogenetic relationship was observed between strain ANT.BR and the purple bacterium Rhodoferax fermentans FR2T, and the two organisms shared several physiological and other phenotypic properties, with the notable exception of growth temperature optimum. Tests of genomic DNA hybridization, however, showed Rfx. fermentans FR2T and strain ANT.BR to be genetically distinct bacteria. Because of its unique set of properties, especially its requirement for low growth temperatures, we propose to recognize strain ANT.BR as a new species of the genus Rhodoferax, Rhodoferax antarcticus, named for its known habitat, the Antarctic.

  16. Influence of hydraulic retention time on the psychrophilic hydrolysis/acidogenesis of proteins.

    PubMed

    Poirrier, Paola; Schiappacasse, María Cristina; Carballa, Marta; Lema, Juan M

    2016-11-01

    The influence of the hydraulic retention time (HRT) on the anaerobic hydrolysis of complex substrates has been studied under psychrophilic conditions. For this purpose, a continuous stirred tank reactor was operated at 15 °C and neutral pH and gelatin was considered as a model protein. Three HRTs have been tested: 12, 21 and 36 h. Gelatin hydrolysis was greatly dependent on HRT, increasing from 40% at 12 h-HRT to a maximum of 65% at 36 h-HRT. Molecular size distribution analyses of the effluent showed that hydrolysation of compounds larger than 10 kDa was poor at 12 h-HRT, whereas the fraction of 1-10 kDa was completely transformed into compounds smaller than 1 kDa. Higher HRT (36 h) improved the degradation of the recalcitrant fraction (>10 kDa), obtaining an effluent with around 95% of soluble molecules (<1 kDa). In that way, the use of membrane bioreactors for the treatment of this type of macromolecules could improve the degradation efficiencies by enabling to increase the residence time of the non-hydrolyzed molecules, with what would be possible to achieve higher organic loading rate operation.

  17. Glutathionylation of the iron superoxide dismutase from the psychrophilic eubacterium Pseudoalteromonas haloplanktis.

    PubMed

    Castellano, Immacolata; Ruocco, Maria Rosaria; Cecere, Francesca; Di Maro, Antimo; Chambery, Angela; Michniewicz, Andzelika; Parlato, Giuseppe; Masullo, Mariorosario; De Vendittis, Emmanuele

    2008-05-01

    Our previous work showed that the adduct between beta-mercaptoethanol and the single cysteine residue (Cys57) in superoxide dismutase from the psychrophilic eubacterium Pseudoalteromonas haloplanktis (PhSOD) reduces the enzyme inactivation by peroxynitrite. In this work, immunoblotting experiments prove that peroxynitrite inactivation of PhSOD involves formation of nitrotyrosine residue(s). In order to study the role of Cys57 as a redox-sensor residue modifiable by cellular thiols, a recombinant PhSOD and two Cys57 mutants were produced and characterized. Recombinant and mutant enzymes share similar activity and peroxynitrite inactivation, but different reactivity towards three glutathione forms. Indeed, oxidized glutathione and S-nitrosoglutathione, but reduced glutathione, lead to S-glutathionylation of recombinant PhSOD. This new covalent modification for a Fe-SOD does not occur in both Cys57 mutants, thus indicating that its target is Cys57. Moreover, mass spectrometry analysis confirmed that S-glutathionylation of Cys57 takes place also with endogenous PhSOD. Formation of this mixed disulfide in PhSOD protects the enzyme from tyrosine nitration and peroxynitrite inactivation. PhSOD undergoes S-glutathionylation during its overproduction in E. coli cells and in a growing culture of P. haloplanktis. In both cases the extent of glutathionylated PhSOD is enhanced upon cell exposure to oxidative agents. We suggest that S-glutathionylation of PhSOD could represent a further cold-adaptation strategy to improve the antioxidant cellular defence mechanism.

  18. Proteolysis in hyperthermophilic microorganisms

    DOE PAGES

    Ward, Donald E.; Shockley, Keith R.; Chang, Lara S.; ...

    2002-01-01

    Proteases are found in every cell, where they recognize and break down unneeded or abnormal polypeptides or peptide-based nutrients within or outside the cell. Genome sequence data can be used to compare proteolytic enzyme inventories of different organisms as they relate to physiological needs for protein modification and hydrolysis. In this review, we exploit genome sequence data to compare hyperthermophilic microorganisms from the euryarchaeotal genus Pyrococcus , the crenarchaeote Sulfolobus solfataricus , and the bacterium Thermotoga maritima . An overview of the proteases in these organisms is given based on those proteases that have been characterized and on putativemore » proteases that have been identified from genomic sequences, but have yet to be characterized. The analysis revealed both similarities and differences in the mechanisms utilized for proteolysis by each of these hyperthermophiles and indicated how these mechanisms relate to proteolysis in less thermophilic cells and organisms.« less

  19. Gravitaxis in unicellular microorganisms

    NASA Astrophysics Data System (ADS)

    Häder, D.-P.

    1999-01-01

    Orientation of organisms with respect to the gravitational field of the Earth has been studied for more than 100 years in a number of unicellular microorganisms including flagellates and ciliates. Several hypotheses have been developed how the weak stimulus is perceived. Intracellular statoliths have been found to be involved in gravitaxis of Loxodes, while no specialized organelles have been detected in other ciliates, e.g. Paramecium. Also in the slime mold Physarum no specialized gravireceptors have been identified yet. In the flagellate Euglena gracilis the whole cell body, which is denser than the surrounding medium, seems to act as a statolith pressing onto the lower membrane where it activates mechanosensitive ion channels. Similar results were obtained for the ciliate Paramecium. In contrast to the flagellate Euglena, several ciliates have been found to show gravikinesis, which is defined as a dependence of the swimming velocity on the direction of movement in the gravity field.

  20. Thermophilic microorganisms in biomining.

    PubMed

    Donati, Edgardo Rubén; Castro, Camila; Urbieta, María Sofía

    2016-11-01

    Biomining is an applied biotechnology for mineral processing and metal extraction from ores and concentrates. This alternative technology for recovering metals involves the hydrometallurgical processes known as bioleaching and biooxidation where the metal is directly solubilized or released from the matrix for further solubilization, respectively. Several commercial applications of biomining can be found around the world to recover mainly copper and gold but also other metals; most of them are operating at temperatures below 40-50 °C using mesophilic and moderate thermophilic microorganisms. Although biomining offers an economically viable and cleaner option, its share of the world´s production of metals has not grown as much as it was expected, mainly considering that due to environmental restrictions in many countries smelting and roasting technologies are being eliminated. The slow rate of biomining processes is for sure the main reason of their poor implementation. In this scenario the use of thermophiles could be advantageous because higher operational temperature would increase the rate of the process and in addition it would eliminate the energy input for cooling the system (bioleaching reactions are exothermic causing a serious temperature increase in bioreactors and inside heaps that adversely affects most of the mesophilic microorganisms) and it would decrease the passivation of mineral surfaces. In the last few years many thermophilic bacteria and archaea have been isolated, characterized, and even used for extracting metals. This paper reviews the current status of biomining using thermophiles, describes the main characteristics of thermophilic biominers and discusses the future for this biotechnology.

  1. Extensive gene acquisition in the extremely psychrophilic bacterial species Psychroflexus torquis and the link to sea-ice ecosystem specialism.

    PubMed

    Feng, Shi; Powell, Shane M; Wilson, Richard; Bowman, John P

    2014-01-01

    Sea ice is a highly dynamic and productive environment that includes a diverse array of psychrophilic prokaryotic and eukaryotic taxa distinct from the underlying water column. Because sea ice has only been extensive on Earth since the mid-Eocene, it has been hypothesized that bacteria highly adapted to inhabit sea ice have traits that have been acquired through horizontal gene transfer (HGT). Here we compared the genomes of the psychrophilic bacterium Psychroflexus torquis ATCC 700755(T), associated with both Antarctic and Arctic sea ice, and its closely related nonpsychrophilic sister species, P. gondwanensis ACAM 44(T). Results show that HGT has occurred much more extensively in P. torquis in comparison to P. gondwanensis. Genetic features that can be linked to the psychrophilic and sea ice-specific lifestyle of P. torquis include genes for exopolysaccharide (EPS) and polyunsaturated fatty acid (PUFA) biosynthesis, numerous specific modes of nutrient acquisition, and proteins putatively associated with ice-binding, light-sensing (bacteriophytochromes), and programmed cell death (metacaspases). Proteomic analysis showed that several genes associated with these traits are highly translated, especially those involved with EPS and PUFA production. Because most of the genes relating to the ability of P. torquis to dwell in sea-ice ecosystems occur on genomic islands that are absent in closely related P. gondwanensis, its adaptation to the sea-ice environment appears driven mainly by HGT. The genomic islands are rich in pseudogenes, insertional elements, and addiction modules, suggesting that gene acquisition is being followed by a process of genome reduction potentially indicative of evolving ecosystem specialism.

  2. The genome sequence of the psychrophilic archaeon, Methanococcoides burtonii: the role of genome evolution in cold adaptation

    SciTech Connect

    Allen, Michele A; Lauro, Federico M; Williams, Timothy J; Burg, Dominic; Siddiqui, Khawar S; DeFrancisci, Davide; Chong, Kevin WY; Pilak, Oliver; Chew, Hwee H; DeMaere, Matthew Z; Ting, Lily; Katrib, Marilyn; Ng, Charmaine; Sowers, Kevin R; Galperin, Michael Y.; Anderson, Iain; Ivanova, N; Dalin, Eileen; Martinez, Michele; Lapidus, Alla L.; Hauser, Loren John; Land, Miriam L; Thomas, Torsten; Cavicchioli, Ricardo

    2009-01-01

    Psychrophilic archaea are abundant and perform critical roles throughout the Earth's expansive cold biosphere. Here we report the first complete genome sequence for a psychrophilic methanogenic archaeon, Methanococcoides burtonii. The genome sequence was manually annotated including the use of a five-tiered evidence rating (ER) system that ranked annotations from ER1 (gene product experimentally characterized from the parent organism) to ER5 (hypothetical gene product) to provide a rapid means of assessing the certainty of gene function predictions. The genome is characterized by a higher level of aberrant sequence composition (51%) than any other archaeon. In comparison to hyper/thermophilic archaea, which are subject to selection of synonymous codon usage, M. burtonii has evolved cold adaptation through a genomic capacity to accommodate highly skewed amino-acid content, while retaining codon usage in common with its mesophilic Methanosarcina cousins. Polysaccharide biosynthesis genes comprise at least 3.3% of protein coding genes in the genome, and Cell wall, membrane, envelope biogenesis COG genes are overrepresented. Likewise, signal transduction (COG category T) genes are overrepresented and M. burtonii has a high 'IQ' (a measure of adaptive potential) compared to many methanogens. Numerous genes in these two overrepresented COG categories appear to have been acquired from - and -Proteobacteria, as do specific genes involved in central metabolism such as a novel B form of aconitase. Transposases also distinguish M. burtonii from other archaea, and their genomic characteristics indicate they have an important role in evolving the M. burtonii genome. Our study reveals a capacity for this model psychrophile to evolve through genome plasticity (including nucleotide skew, horizontal gene transfer and transposase activity) that enables adaptation to the cold, and to the biological and physical changes that have occurred over the last several thousand years as it

  3. Cytochrome f from the Antarctic psychrophile, Chlamydomonas raudensis UWO 241: structure, sequence, and complementation in the mesophile, Chlamydomonas reinhardtii.

    PubMed

    Gudynaite-Savitch, Loreta; Gretes, Michael; Morgan-Kiss, Rachael M; Savitch, Leonid V; Simmonds, John; Kohalmi, Susanne E; Hüner, Norman P A

    2006-04-01

    Although cytochrome f from the Antarctic psychrophile, Chlamydomonas raudensis UWO 241, exhibits a lower apparent molecular mass (34 kD) than that of the mesophile C. reinhardtii (41 kD) based on SDS-PAGE, both proteins are comparable in calculated molecular mass and show 79% identity in amino acid sequence. The difference in apparent molecular mass was maintained after expression of petA from both Chlamydomonas species in either E. coli or a C. reinhardtii DeltapetA mutant and after substitution of a unique third cysteine-292 to phenylalanine in the psychrophilic cytochrome f. Moreover, the heme of the psychrophilic form of cytochrome f was less stable upon heating than that of the mesophile. In contrast to C. raudensis, a C. reinhardtii DeltapetA mutant transformed with petA from C. raudensis exhibited the ability to undergo state transitions and a capacity for intersystem electron transport comparable to that of C. reinhardtii wild type. However, the C. reinhardtii petA transformants accumulated lower levels of cytochrome b ( 6 ) /f complexes and exhibited lower light saturated rates of O(2) evolution than C. reinhardtii wild type. We show that the presence of an altered form of cytochrome f in C. raudensis does not account for its inability to undergo state transitions or its impaired capacity for intersystem electron transport as previously suggested. A combined survey of the apparent molecular mass, thermal stability and amino acid sequences of cytochrome f from a broad range of mesophilic species shows unequivocally that the observed differences in cytochrome f structure are not related to psychrophilly. Thus, caution must be exercised in relating differences in amino acid sequence and thermal stability to adaptation to cold environments.

  4. Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus

    PubMed Central

    Miao, Li-Li; Hou, Yan-Jie; Fan, Hong-Xia; Qu, Jie; Qi, Chao; Liu, Ying

    2016-01-01

    Psychrophilic enzymes play crucial roles in cold adaptation of microbes and provide useful models for studies of protein evolution, folding, and dynamic properties. We examined the crystal structure (2.2-Å resolution) of the psychrophilic β-glucosidase BglU, a member of the glycosyl hydrolase 1 (GH1) enzyme family found in the cold-adapted bacterium Micrococcus antarcticus. Structural comparison and sequence alignment between BglU and its mesophilic and thermophilic counterpart enzymes (BglB and GlyTn, respectively) revealed two notable features distinct to BglU: (i) a unique long-loop L3 (35 versus 7 amino acids in others) involved in substrate binding and (ii) a unique amino acid, His299 (Tyr in others), involved in the stabilization of an ordered water molecule chain. Shortening of loop L3 to 25 amino acids reduced low-temperature catalytic activity, substrate-binding ability, the optimal temperature, and the melting temperature (Tm). Mutation of His299 to Tyr increased the optimal temperature, the Tm, and the catalytic activity. Conversely, mutation of Tyr301 to His in BglB caused a reduction in catalytic activity, thermostability, and the optimal temperature (45 to 35°C). Loop L3 shortening and H299Y substitution jointly restored enzyme activity to the level of BglU, but at moderate temperatures. Our findings indicate that loop L3 controls the level of catalytic activity at low temperatures, residue His299 is responsible for thermolability (particularly heat lability of the active center), and long-loop L3 and His299 are jointly responsible for the psychrophilic properties. The described structural basis for the cold adaptedness of BglU will be helpful for structure-based engineering of new cold-adapted enzymes and for the production of mutants useful in a variety of industrial processes at different temperatures. PMID:26801571

  5. The Genome Sequence of the psychrophilic archaeon, Methanococcoides burtonii: the Role of Genome Evolution in Cold-adaptation

    SciTech Connect

    Allen, Michelle A.; Lauro, Federico M.; Williams, Timothy J.; Burg, Dominic; Siddiqui, Khawar S.; De Francisci, David; Chong, Kevin W.Y.; Pilak, Oliver; Chew, Hwee H.; De Maere, Matthew Z.; Ting, Lily; Katrib, Marilyn; Ng, Charmaine; Sowers, Kevin R.; Galperin, Michael Y.; Anderson, Iain J.; Ivanova, Natalia; Dalin, Eileen; Martinez, Michelle; Lapidus, Alla; Hauser, Loren; Land, Miriam; Thomas, Torsten; Cavicchioli, Ricardo

    2009-04-01

    Psychrophilic archaea are abundant and perform critical roles throughout the Earth's expansive cold biosphere. Here we report the first complete genome sequence for a psychrophilic methanogenic archaeon, Methanococcoides burtonii. The genome sequence was manually annotated including the use of a five tiered Evidence Rating system that ranked annotations from Evidence Rating (ER) 1 (gene product experimentally characterized from the parent organism) to ER5 (hypothetical gene product) to provide a rapid means of assessing the certainty of gene function predictions. The genome is characterized by a higher level of aberrant sequence composition (51%) than any other archaeon. In comparison to hyper/thermophilic archaea which are subject to selection of synonymous codon usage, M. burtonii has evolved cold adaptation through a genomic capacity to accommodate highly skewed amino acid content, while retaining codon usage in common with its mesophilic Methanosarcina cousins. Polysaccharide biosynthesis genes comprise at least 3.3% of protein coding genes in the genome, and Cell wall/membrane/envelope biogenesis COG genes are over-represented. Likewise, signal transduction (COG category T) genes are over-represented and M. burtonii has a high 'IQ' (a measure of adaptive potential) compared to many methanogens. Numerous genes in these two over-represented COG categories appear to have been acquired from {var_epsilon}- and {delta}-proteobacteria, as do specific genes involved in central metabolism such as a novel B form of aconitase. Transposases also distinguish M. burtonii from other archaea, and their genomic characteristics indicate they play an important role in evolving the M. burtonii genome. Our study reveals a capacity for this model psychrophile to evolve through genome plasticity (including nucleotide skew, horizontal gene transfer and transposase activity) that enables adaptation to the cold, and to the biological and physical changes that have occurred over the

  6. Microorganisms in honey.

    PubMed

    Snowdon, J A; Cliver, D O

    1996-08-01

    Knowledge of the moisture and temperature conditions influencing growth of microorganisms in honey has long been used to control the spoilage of honey. However, the need for additional microbiological data on honey will increase as new technologies for, and uses of honey develop. Microorganisms in honey may influence quality or safety. Due to the natural properties of honey and control measures in the honey industry, honey is a product with minimal types and levels of microbes. Microbes of concern in post-harvest handling are those that are commonly found in honey (i.e., yeasts and spore-forming bacteria), those that indicate the sanitary or commercial quality of honey (i.e., coliforms and yeasts), and those that under certain conditions could cause human illness. Primary sources of microbial contamination are likely to include pollen, the digestive tracts of honey bees, dust, air, earth and nectar, sources which are very difficult to control. The same secondary (after-harvest) sources that influence any food product are also sources of contamination for honey. These include air, food handlers, cross-contamination, equipment and buildings. Secondary sources of contamination are controlled by good manufacturing practices. The microbes of concern in honey are primarily yeasts and spore-forming bacteria. Total plate counts from honey samples can vary from zero to tens of thousands per gram for no apparent reason. Most samples of honey contain detectable levels of yeasts. Although yeast counts in many honey samples are below 100 colony forming units per gram (cfu/g), yeasts can grow in honey to very high numbers. Standard industry practices control yeast growth. Bacterial spores, particularly those in the Bacillus genus, are regularly found in honey. The spores of C. botulinum are found in a fraction of the honey samples tested-normally at low levels. No vegetative forms of disease-causing bacterial species have been found in honey. Bacteria do not replicate in honey

  7. Phosphate-independent utilization of phosphonoacetic acid as sole phosphorus source by a psychrophilic strain of Geomyces pannorum P15.

    PubMed

    Klimek-Ochab, Magdalena

    2014-09-01

    A psychrophilic fungal strain of Geomyces pannorum P15 was screened for its ability to utilize a range of synthetic and natural organophosphonate compounds as the sole source of phosphorus, nitrogen, or carbon. Only phosphonoacetic acid served as a phosphorus source for microbial growth in phosphate-independent manner. Substrate metabolism did not lead to extracellular release of inorganic phosphate. No phosphonate metabolizing enzyme activity was detectable in cell-free extracts prepared from Geomyces biomass pregrown on 2 mmol/L phosphonoacetic acid.

  8. Complete genome sequence of the Sporosarcina psychrophila DSM 6497, a psychrophilic Bacillus strain that mediates the calcium carbonate precipitation.

    PubMed

    Yan, Wenkai; Xiao, Xiang; Zhang, Yu

    2016-05-20

    Sporosarcina psychrophila DSM 6497 is a gram positive, spore-formation psychrophilic bacterial strain, widely distributed in terrestrial and aquatic environments. Here we report its complete sequence including one circular chromosome of 4674191bp with a GC content of 40.3%. Genes encoding urease are predicted in the genome, which provide insight information on the microbiologically mediated urea hydrolysis process. This urea hydrolysis can further lead to an increase of carbonate anion and alkalinity in the environment, which promotes the microbiologically induced carbonate precipitation with various applications, such as the bioremediation of calcium rich wastewater and bio-reservation of architectural patrimony.

  9. Local entropy difference upon a substrate binding of a psychrophilic α-amylase and a mesophilic homologue

    NASA Astrophysics Data System (ADS)

    Kosugi, Takahiro; Hayashi, Shigehiko

    2011-01-01

    Psychrophilic α-amylase from the antarctic bacterium pseudoalteromonashaloplanktis (AHA) and its mesophilic homologue, porcine pancreatic α-amylase (PPA) are theoretically investigated with molecular dynamics (MD) simulations. We carried out 240-ns MD simulations for four systems, AHA and PPA with/without the bound substrate, and examined protein conformational entropy changes upon the substrate binding. We developed an analysis that decomposes the entropy changes into contributions of individual amino acids, and successfully identified protein regions responsible for the entropy changes. The results provide a molecular insight into the structural flexibilities of those enzymes related to the temperature dependences of the enzymatic activity.

  10. Social evolution theory for microorganisms.

    PubMed

    West, Stuart A; Griffin, Ashleigh S; Gardner, Andy; Diggle, Stephen P

    2006-08-01

    Microorganisms communicate and cooperate to perform a wide range of multicellular behaviours, such as dispersal, nutrient acquisition, biofilm formation and quorum sensing. Microbiologists are rapidly gaining a greater understanding of the molecular mechanisms involved in these behaviours, and the underlying genetic regulation. Such behaviours are also interesting from the perspective of social evolution - why do microorganisms engage in these behaviours given that cooperative individuals can be exploited by selfish cheaters, who gain the benefit of cooperation without paying their share of the cost? There is great potential for interdisciplinary research in this fledgling field of sociomicrobiology, but a limiting factor is the lack of effective communication of social evolution theory to microbiologists. Here, we provide a conceptual overview of the different mechanisms through which cooperative behaviours can be stabilized, emphasizing the aspects most relevant to microorganisms, the novel problems that microorganisms pose and the new insights that can be gained from applying evolutionary theory to microorganisms.

  11. Polysaccharides from Extremophilic Microorganisms

    NASA Astrophysics Data System (ADS)

    Nicolaus, B.; Moriello, V. Schiano; Lama, L.; Poli, A.; Gambacorta, A.

    2004-02-01

    Several marine thermophilic strains were analyzed for exopolysaccharide production. The screening process revealed that a significant number of thermophilic microorganisms were able to produce biopolymers, and some of them also revealed interesting chemical compositions. We have identified four new polysaccharides from thermophilic marine bacteria, with complex primary structures and with different repetitive units: a galacto-mannane type from strain number 4004 and mannane type for the other strains. The thermophilic Bacillus thermantarcticus produces two exocellular polysaccharides (EPS 1, EPS 2) that give the colonies a typical mucous character. The exopolysaccharide fraction was produced with all substrates assayed, although a higher yield 400 mg liter-1 was obtained with mannose as carbon and energy source. NMR spectra confirmed that EPS 1 was a heteropolysaccharide of which the repeating unit was constituted by four different α-D-mannoses and three different β-D-glucoses. It seems to be close to some xantan polymers. EPS 2 was a mannan. Four different α-D-mannoses were found as the repeating unit. Production and chemical studies of biopolymers produced by halophilic archaea, Haloarcula species were also reported.

  12. 40 CFR 725.420 - Recipient microorganisms.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Recipient microorganisms. 725.420... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS General Exemptions for New Microorganisms § 725.420 Recipient microorganisms. The following recipient microorganisms are eligible for...

  13. 40 CFR 725.420 - Recipient microorganisms.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Recipient microorganisms. 725.420... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS General Exemptions for New Microorganisms § 725.420 Recipient microorganisms. The following recipient microorganisms are eligible for...

  14. 40 CFR 725.420 - Recipient microorganisms.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Recipient microorganisms. 725.420... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS General Exemptions for New Microorganisms § 725.420 Recipient microorganisms. The following recipient microorganisms are eligible for...

  15. 40 CFR 725.420 - Recipient microorganisms.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Recipient microorganisms. 725.420... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS General Exemptions for New Microorganisms § 725.420 Recipient microorganisms. The following recipient microorganisms are eligible for...

  16. 40 CFR 725.420 - Recipient microorganisms.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Recipient microorganisms. 725.420... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS General Exemptions for New Microorganisms § 725.420 Recipient microorganisms. The following recipient microorganisms are eligible for...

  17. Biocatalysis and biotransformation of resveratrol in microorganisms.

    PubMed

    Mei, Yan-Zhen; Liu, Ruo-Xue; Wang, Dong-Peng; Wang, Xia; Dai, Chuan-Chao

    2015-01-01

    Resveratrol, a major stilbene phytoalexin, is a valuable polyphenol that has been recognized for its benefits to human health. Resveratrol has antioxidant and antitumor effects and promotes longevity. It is used in medicine, health care products, cosmetics, and other industries. Therefore, a sustainable source for resveratrol production is required. This review describes the metabolic engineering of microorganisms, the biotransformation and biosynthesis of endophytes and the oxidation or degradation of resveratrol. We compare various available methods for resveratrol production, and summarize the practical challenges facing the microbial production of resveratrol. The future research direction for resveratrol is also discussed.

  18. Cloning and in-silico analysis of beta-1,3-xylanase from psychrophilic yeast, Glaciozyma antarctica PI12

    NASA Astrophysics Data System (ADS)

    Nor, Nooraisyah Mohamad; Bakar, Farah Diba Abu; Mahadi, Nor Muhammad; Murad, Abdul Munir Abdul

    2015-09-01

    A beta-1,3-xylanase (EC 3.2.1.32) gene from psychrophilic yeast, Glaciozyma antarctica has been identified via genome data mining. The enzyme was grouped into GH26 family based on Carbohydrate Active Enzyme (CaZY) database. The molecular weight of this protein was predicted to be 42 kDa and is expected to be soluble for expression. The presence of signal peptide suggested that this enzyme may be released extracellularly into the marine environment of the host's habitat. This supports the theory that such enzymatic activity is required for degradation of nutrients of polysaccharide origins into simpler carbohydrates outside the environment before it could be taken up inside the cell. The sequence for this protein showed very little conservation (< 30%) with other beta-1,3-xylanases from available databases. Based on the phylogenetic analysis, this protein also showed distant relationship to other xylanases from eukaryotic origin. The protein may have undergone major substitution in its gene sequence order to adapt to the cold climate. This is the first report of beta-1,3-xylanase gene isolated from a psychrophilic yeast.

  19. Engineering Microorganisms for Energy Production

    DTIC Science & Technology

    2006-06-01

    focus for the Department of Energy. Microorganisms are simpler than plants; they have smaller genomes and proteomes, and are eas- ier to manipulate and...opportunity. The synergy between research into biofuel production by microorgan- isms and the Genomes to Life program is important and should be fully...producing energy: this is an important problem in basic energy science, whose solution will require synergistic interactions with genomics , synthetic and

  20. Sensor arrays for detecting microorganisms

    NASA Technical Reports Server (NTRS)

    Lewis, Nathan S. (Inventor); Freund, Michael S. (Inventor)

    2000-01-01

    A sensor array for detecting a microorganism comprising first and second sensors electrically connected to an electrical measuring apparatus, wherein the sensors comprise a region of nonconducting organic material and a region of conducting material compositionally that is different than the nonconducting organic material and an electrical path through the regions of nonconducting organic material and the conducting material. A system for identifying microorganisms using the sensor array, a computer and a pattern recognition algorithm, such as a neural net are also disclosed.

  1. Textiles for protection against microorganism

    NASA Astrophysics Data System (ADS)

    Sauperl, O.

    2016-04-01

    Concerning micro-organisms such as bacteria, viruses and fungi, there is a huge progress in the development of textile materials and procedures which should effectively protect against these various pathogens. In this sense there is especially problematic hospital environment, where it is necessary to take into account properly designed textile material which, when good selected and composed, act as a good barrier against transfer of micro-organisms through material mainly in its wet state. Respect to this it is necessary to be familiar with the rules regarding selection of the input material, the choice of proper yarn construction, the choice of the proper weaving mode, the rules regarding selection of antimicrobial-active compound suitable for (eco-friendly) treatment, and the choice of the most appropriate test method by which it is possible objectively to conclude on the reduction of selected microorganism. As is well known, fabrics are three-dimensional structures with void and non-void areas. Therefore, the physical-chemical properties of the textile material/fabric, the surface characteristics together with the shape of microorganism, and the carriers' characteristics contribute to control the transfer of microorganism through textile material. Therefore, careful planning of textile materials and treatment procedure with the compound which is able to reduce micro-organism satisfactory is particularly important, especially due to the fact that in hospital environment population with impaired immune system is mainly presented.

  2. Differential cold-adaptation among protein components of the thioredoxin system in the psychrophilic eubacterium Pseudoalteromonas haloplanktis TAC 125.

    PubMed

    Cotugno, Roberta; Rosaria Ruocco, Maria; Marco, Salvatore; Falasca, Patrizia; Evangelista, Giovanna; Raimo, Gennaro; Chambery, Angela; Di Maro, Antimo; Masullo, Mariorosario; De Vendittis, Emmanuele

    2009-05-01

    Thioredoxin and thioredoxin reductase from the psychrophilic eubacterium Pseudoalteromonas haloplanktis were obtained as recombinant His-tagged proteins (rPhTrx and rPhTrxR, respectively). rPhTrxR is organised as a homodimeric flavoenzyme, whereas rPhTrx is a small monomeric protein, both containing a functional disulfide bridge. However, three additional cysteines are present as free thiols in purified rPhTrxR. When individually tested in specific assays, rPhTrxR and rPhTrx display a full activity at low temperatures, an indispensable requirement for cold-adapted proteins. In particular, rPhTrxR catalyses the NADPH dependent reduction of DTNB and rPhTrx provokes the insulin precipitation in the presence of DTT. The analysis of the effect of temperature on these reactions indicates that rPhTrxR is more cold-adapted than rPhTrx, having a higher psychrophilicity. The combined activity of rPhTrxR and rPhTrx, tested in a reconstituted assay containing NADPH as electrons donor and human insulin as the thioredoxin substrate, demonstrates a direct functional interaction between the purified recombinant components of the thioredoxin system of P. haloplanktis. Furthermore, the NADPH-dependent reduction of rPhTrx catalysed by rPhTrxR is fully reversible and allows the determination of its redox potential, whose value is in the range of other bacterial and archaeal thioredoxins. The analysis of the thermostability of rPhTrxR points to its discrete heat resistance. However, rPhTrx is much more heat resistant, with a half inactivation time of about 4 h at 95 degrees C. This exceptional heat resistance for a psychrophilic protein is significantly decreased by the reduction of the disulfide bridge of rPhTrx. Functionality, thermodependence and thermostability of the P. haloplanktis thioredoxin system point to the relevance of this key mechanism for the preservation of the reduced state of cytoplasmic proteins even in a cold-adapted source.

  3. Behavior of microorganisms at lower temperature

    NASA Astrophysics Data System (ADS)

    Ishida, Yuzaburo

    The liquid-crystalline state (fluidity) in the bacterial membrane lipid is essential for the protem in lipid bilayer to mediate the various functions. The transition ternperature in gel to liquid-crystalline phase is mainly dependent on the chain length and geornetry of the fatty acyl chains. That is, the melting points of the saturated fatty bcids decrease as the length of the hydrocarbon chain decreases the monounsaturated fatty acids are the lowest-melting. Fatty acids cornposition of the membrane lipids changes repidly in response to alterations in the environmental temperature, and also there is an appreciable difference in the fatty acids cornposition between psychrophile, mesophile and thermophile.

  4. Dry anaerobic digestion of high solids content dairy manure at high organic loading rates in psychrophilic sequence batch reactor.

    PubMed

    Massé, Daniel I; Saady, Noori M Cata

    2015-05-01

    Cow manure with bedding is renewable organic biomass available around the year on dairy farms. Developing efficient and cost-effective psychrophilic dry anaerobic digestion (PDAD) processes could contribute to solving farm-related environmental, energy, and manure management problems in cold-climate regions. This study was to increase the organic loading rate (OLR), fed to a novel psychrophilic (20 °C) dry anaerobic digestion of 27% total solid dairy manure (cow feces and wheat straw) in sequence batch reactor (PDAD-SBR), by 133 to 160%. The PDAD-SBR process operated at treatment cycle length of 21 days and OLR of 7.0 and 8.0 g total chemical oxygen demand (TCOD) kg(-1) inoculum day(-1) (5.2 ± 0.1 and 5.8 ± 0.0 g volatile solids (VS) kg(-1) inoculum day(-1)) for four successive cycles (84 days) produced average specific methane yields (SMYs) of 147.1 ± 17.2 and 143.2 ± 11.7 normalized liters (NL) CH4 kg(-1) VS fed, respectively. PDAD of cow feces and wheat straw is possible with VS-based inoculum-to-substrate ratio of 1.45 at OLR of 8.0 g TCOD kg(-1) inoculum day(-1). Hydrolysis was the limiting step reaction. The VS removal averaged around 57.4 ± 0.5 and 60.5 ± 5.7% at OLR 7.0 and 8.0 g TCOD kg(-1) inoculum day(-1), respectively.

  5. PCB breakdown by anaerobic microorganisms

    SciTech Connect

    Not Available

    1989-03-01

    Recently, altered PCB cogener distribution patterns observed in anaerobic sediment samples from the upper Hudson River are being attributed to biologically mediated reductive dechlorination. The authors report their successful demonstration of biologically mediated reductive dechlorination of an Aroclor mixture. In their investigation, they assessed the ability of microorganisms from PCB-contaminated Hudson River sediments (60-562 ppm PCBs) to dechlorinate Aroclor 1242 under anaerobic conditions by eluting microorganisms from the PCB- contaminated sediments and transferring them to a slurry of reduced anaerobic mineral medium and PCB-free sediments in tightly stoppered bottles. They observed dechlorination to be the most rapid at the highest PCB concentration tried by them.

  6. Smaller Fleas: Viruses of Microorganisms

    PubMed Central

    Hyman, Paul; Abedon, Stephen T.

    2012-01-01

    Life forms can be roughly differentiated into those that are microscopic versus those that are not as well as those that are multicellular and those that, instead, are unicellular. Cellular organisms seem generally able to host viruses, and this propensity carries over to those that are both microscopic and less than truly multicellular. These viruses of microorganisms, or VoMs, in fact exist as the world's most abundant somewhat autonomous genetic entities and include the viruses of domain Bacteria (bacteriophages), the viruses of domain Archaea (archaeal viruses), the viruses of protists, the viruses of microscopic fungi such as yeasts (mycoviruses), and even the viruses of other viruses (satellite viruses). In this paper we provide an introduction to the concept of viruses of microorganisms, a.k.a., viruses of microbes. We provide broad discussion particularly of VoM diversity. VoM diversity currently spans, in total, at least three-dozen virus families. This is roughly ten families per category—bacterial, archaeal, fungal, and protist—with some virus families infecting more than one of these microorganism major taxa. Such estimations, however, will vary with further discovery and taxon assignment and also are dependent upon what forms of life one includes among microorganisms. PMID:24278736

  7. Venturing into new realms? Microorganisms in space.

    PubMed

    Moissl-Eichinger, Christine; Cockell, Charles; Rettberg, Petra

    2016-09-01

    One of the biggest challenges of science is the determination of whether extraterrestrial life exists. Although potential habitable areas might be available for complex life, it is more likely that microbial life could exist in space. Many extremotolerant and extremophilic microbes have been found to be able to withstand numerous, combined environmental factors, such as high or low temperatures and pressures, high-salt conditions, high doses of radiation, desiccation or nutrient limitations. They may even survive the transit from one planet to another. Terrestrial Mars-analogue sites are one focus of researchers, in order to understand the microbial diversity in preparation for upcoming space missions aimed at the detection of life. However, such missions could also pose a risk with respect to contamination of the extraterrestrial environment by accidentally transferred terrestrial microorganisms. Closer to the Earth, the International Space Station is the most enclosed habitat, where humans work and live-and with them numerous microorganisms. It is still unknown how microbes adapt to this environment, possibly even creating a risk for the crew. Information on the microbiology of the ISS will have an impact on the planning and implementation of long-term human spaceflights in order to ensure a safe, stable and balanced microbiome on board.

  8. A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission

    NASA Technical Reports Server (NTRS)

    Foster, T. L.

    1974-01-01

    The effect of storage of dry heat treated Teflon ribbons under nitrogen gas followed by high vacuum on the recovery of hardy organisms from the ribbons was studied. A similar experiment was performed on spore crops of hardy organisms recovered previously from Cape Canaveral. Hardy organisms have been inoculated onto slides and subjected to an artificial Martian environment in an attempt to demonstrate their growth in this environment. Additional experiments using the artificial Martian environment include response of soil samples from the VAB with both constant temperature and freeze-thaw cycles. These experiments were performed with dried soil and soil containing added water. Other investigations included the effect of heatshock on soil samples, psychrophilic counts of new soil samples from the manufacture area of the Viking spacecraft, effect of pour plate versus spread plate on psychrophilic counts, and preparation of spore crops of hardy organisms from Cape Canaveral.

  9. Crystallization and preliminary X-ray diffraction studies of tetrameric malate dehydrogenase from the novel Antarctic psychrophile Flavobacterium frigidimaris KUC-1

    SciTech Connect

    Fujii, Tomomi; Oikawa, Tadao; Muraoka, Ikuo; Soda, Kenji; Hata, Yasuo

    2007-11-01

    A psychrophilic malate dehydrogenase from the novel Antarctic bacterium F. frigidimaris KUC-1 was crystallized using the hanging-drop vapour-diffusion method. The crystals contained one tetrameric molecule per asymmetric unit. The best crystal diffracted to 1.8 Å resolution. Flavobacterium frigidimaris KUC-1 is a novel psychrotolerant bacterium isolated from Antarctic seawater. Malate dehydrogenase (MDH) is an essential metabolic enzyme in the citric acid cycle and has been cloned, overexpressed and purified from F. frigidimaris KUC-1. In contrast to the already known dimeric form of MDH from the psychrophile Aquaspirillium arcticum, F. frigidimaris MDH exists as a tetramer. It was crystallized at 288 K by the hanging-drop vapour-diffusion method using ammonium sulfate as the precipitating agent. The crystal diffracted to a maximum resolution of 1.80 Å. It contains one tetrameric molecule in the asymmetric unit.

  10. Phylogenetic analysis of anaerobic psychrophilic enrichment cultures obtained from a greenland glacier ice core

    NASA Technical Reports Server (NTRS)

    Sheridan, Peter P.; Miteva, Vanya I.; Brenchley, Jean E.

    2003-01-01

    The examination of microorganisms in glacial ice cores allows the phylogenetic relationships of organisms frozen for thousands of years to be compared with those of current isolates. We developed a method for aseptically sampling a sediment-containing portion of a Greenland ice core that had remained at -9 degrees C for over 100,000 years. Epifluorescence microscopy and flow cytometry results showed that the ice sample contained over 6 x 10(7) cells/ml. Anaerobic enrichment cultures inoculated with melted ice were grown and maintained at -2 degrees C. Genomic DNA extracted from these enrichments was used for the PCR amplification of 16S rRNA genes with bacterial and archaeal primers and the preparation of clone libraries. Approximately 60 bacterial inserts were screened by restriction endonuclease analysis and grouped into 27 unique restriction fragment length polymorphism types, and 24 representative sequences were compared phylogenetically. Diverse sequences representing major phylogenetic groups including alpha, beta, and gamma Proteobacteria as well as relatives of the Thermus, Bacteroides, Eubacterium, and Clostridium groups were found. Sixteen clone sequences were closely related to those from known organisms, with four possibly representing new species. Seven sequences may reflect new genera and were most closely related to sequences obtained only by PCR amplification. One sequence was over 12% distant from its closest relative and may represent a novel order or family. These results show that phylogenetically diverse microorganisms have remained viable within the Greenland ice core for at least 100,000 years.

  11. Phylogenetic Analysis of Anaerobic Psychrophilic Enrichment Cultures Obtained from a Greenland Glacier Ice Core

    PubMed Central

    Sheridan, Peter P.; Miteva, Vanya I.; Brenchley, Jean E.

    2003-01-01

    The examination of microorganisms in glacial ice cores allows the phylogenetic relationships of organisms frozen for thousands of years to be compared with those of current isolates. We developed a method for aseptically sampling a sediment-containing portion of a Greenland ice core that had remained at −9°C for over 100,000 years. Epifluorescence microscopy and flow cytometry results showed that the ice sample contained over 6 × 107 cells/ml. Anaerobic enrichment cultures inoculated with melted ice were grown and maintained at −2°C. Genomic DNA extracted from these enrichments was used for the PCR amplification of 16S rRNA genes with bacterial and archaeal primers and the preparation of clone libraries. Approximately 60 bacterial inserts were screened by restriction endonuclease analysis and grouped into 27 unique restriction fragment length polymorphism types, and 24 representative sequences were compared phylogenetically. Diverse sequences representing major phylogenetic groups including alpha, beta, and gamma Proteobacteria as well as relatives of the Thermus, Bacteroides, Eubacterium, and Clostridium groups were found. Sixteen clone sequences were closely related to those from known organisms, with four possibly representing new species. Seven sequences may reflect new genera and were most closely related to sequences obtained only by PCR amplification. One sequence was over 12% distant from its closest relative and may represent a novel order or family. These results show that phylogenetically diverse microorganisms have remained viable within the Greenland ice core for at least 100,000 years. PMID:12676695

  12. Phosphate Biomineralization of Cambrian Microorganisms

    NASA Technical Reports Server (NTRS)

    McKay, David S.; Rozanov, Alexei Yu.; Hoover, Richard B.; Westall, Frances

    1998-01-01

    As part of a long term study of biological markers (biomarkers), we are documenting a variety of features which reflect the previous presence of living organisms. As we study meteorites and samples returned from Mars, our main clue to recognizing possible microbial material may be the presence of biomarkers rather than the organisms themselves. One class of biomarkers consists of biominerals which have either been precipitated directly by microorganisms, or whose precipitation has been influenced by the organisms. Such microbe-mediated mineral formation may include important clues to the size, shape, and environment of the microorganisms. The process of fossilization or mineralization can cause major changes in morphologies and textures of the original organisms. The study of fossilized terrestrial organisms can help provide insight into the interpretation of mineral biomarkers. This paper describes the results of investigations of microfossils in Cambrian phosphate-rich rocks (phosphorites) that were found in Khubsugul, Northern Mongolia.

  13. Microorganism Utilization for Synthetic Milk

    NASA Technical Reports Server (NTRS)

    Morford, Megan A.; Khodadad, Christina L.; Caro, Janicce I.; Spencer, LaShelle E.; Richards, Jeffery T.; Strayer, Richard F.; Birmele, Michele N.; Wheeler, Raymond M.

    2014-01-01

    A desired architecture for long duration spaceflight, like aboard the International Space Station or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of the Synthetic Biology project, Cow in a Column, was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel-through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) in order to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products. For future work, the production of the casein protein for milk would require the development of a genetically modified organism, which was beyond the scope of the original project. Additional trials would be needed to further refine the required

  14. Biomachining: metal etching via microorganisms.

    PubMed

    Díaz-Tena, Estíbaliz; Barona, Astrid; Gallastegui, Gorka; Rodríguez, Adrián; López de Lacalle, L Norberto; Elías, Ana

    2017-05-01

    The use of microorganisms to remove metal from a workpiece is known as biological machining or biomachining, and it has gained in both importance and scientific relevance over the past decade. Conversely to mechanical methods, the use of readily available microorganisms is low-energy consuming, and no thermal damage is caused during biomachining. The performance of this sustainable process is assessed by the material removal rate, and certain parameters have to be controlled for manufacturing the machined part with the desired surface finish. Although the variety of microorganisms is scarce, cell concentration or density plays an important role in the process. There is a need to control the temperature to maintain microorganism activity at its optimum, and a suitable shaking rate provides an efficient contact between the workpiece and the biological medium. The system's tolerance to the sharp changes in pH is quite limited, and in many cases, an acid medium has to be maintained for effective performance. This process is highly dependent on the type of metal being removed. Consequently, the operating parameters need to be determined on a case-by-case basis. The biomachining time is another variable with a direct impact on the removal rate. This biological technique can be used for machining simple and complex shapes, such as series of linear, circular, and square micropatterns on different metal surfaces. The optimal biomachining process should be fast enough to ensure high production, a smooth and homogenous surface finish and, in sum, a high-quality piece. As a result of the high global demand for micro-components, biomachining provides an effective and sustainable alternative. However, its industrial-scale implementation is still pending.

  15. Studying marine microorganisms from space.

    PubMed

    Pedrós-Alió, C; Simó, R

    2002-12-01

    Microorganisms are but a few micrometers in diameter and are not visible to the naked eye. Yet, the large numbers of microorganisms present in the oceans and the global impact of their activities make it possible to observe them from space. Here a few examples of how microorganisms can be studied from satellites are presented. The first case is the best known: the main pigment used in photosynthesis (chlorophyll a) can be determined from satellites. These kinds of studies have contributed a tremendous amount of understanding about the distribution and dynamics of primary production in the oceans. Two other examples will concern analysis of heterotrophic prokaryotic production and estimates of dimethyl sulfide (DMS) concentration and flux to the atmosphere. These three processes are of fundamental importance for the functioning of the biosphere. Marine microbes carry out about half of the total primary production in the planet. A substantial fraction of the respiration in the oceans is due to the activity of heterotrophic prokaryotes. Finally, the flux of DMS to the atmosphere is believed to constitute one of the mechanisms by which the biota can regulate climate. The global implications of microbial processes in the oceans can only be addressed with the help of satellites.

  16. Microorganisms in closed periapical lesions.

    PubMed

    Abou-Rass, M; Bogen, G

    1998-01-01

    The purpose of this study was to investigate the microorganisms of strictly selected closed periapical lesions associated with both refractory endodontic therapy and pulpal calcification. Definitive criteria were established that assured complete clinical isolation of the periapical lesion from the oral and periodontal environment. A total of 13 criteria-referenced lesions were selected from 70 patients with endodontic surgical indications. A well controlled culturing method was used in all cases and samples were taken by one clinician at three separate sites during each surgery. Samples taken at the surgical window and within the body of the lesion served as controls, whilst a third sample was taken at the apex. In all 13 cases, samples taken from the apex yielded microorganisms comprising 63.6% obligate anaerobes and 36.4% facultative anaerobes. Prevalence of the isolated species was 31.8% for Actinomyces sp., 22.7% Propionibacterium sp., 18.2% Streptococcus sp., 13.6% Staphlyococcus sp., 4.6% Porphyromonas gingivalis, 4.6% Peptostreptococcus micros and 4.6% Gram-negative enterics. The results of this investigation indicate that closed periapical lesions associated with calcified teeth or those resistant to root canal treatment harbour bacteria. The inability to eradicate all root canal microorganisms during root canal treatment, along with anatomical factors, may allow further bacterial colonization of the root apex and surrounding periapical tissues, and consequently prevent healing.

  17. Photosynthetic microorganisms in cold environments

    NASA Astrophysics Data System (ADS)

    Kviderova, Jana; Hajek, Josef; Elster, Josef; Bartak, Milos; Vaczi, Peter; Nedbalova, Linda

    The polar regions are considered as a model of extraterrestrial ecosystems. Depending on the average temperature, temperature variation and water availability, these conditions could be used as a model of Mars or Europa (e.g. (Elster and Benson, 2004). Two cases are presented: 1) Stable temperature and water availability The environment of cryosestic communities, i.e. organisms living in snow, is characterized by very stable temperature; the diurnal variations do not exceed 1 -2 ° C (Kváderová, 2010) and a are not usually exposed to freeze/thaw. Water is not usually limiting since the water content could reach up to 54 % (Nedbalová et al., 2008). The windblown sediments are important a source of nutrient and could provide protection against the excess of radiation. The nutrient concentrations in the snow are low are depleted rapidly when massive algal blooms forms. Such environment could be found near Mars polar caps or in Europa ice cover. The snow algae are the most important primary producers in snow. Their adaptation strategy is dependent on the developmental stages; the motile stages avoid the harsh conditions (e.g. high light) and sessile stages acclimatize to actual conditions. The main genera Chlamydomonas and Chloromonas (both Chlorophyta) are psychrophilic. Their growth optimum temperature is lower than 15 ° C and their growth is inhibited at temperatures above 20 ° C. 2) Unstable temperature and water availability The deglaciated surfaces, inhabited by lichen communities, are typical by variation in temper-ature and moisture. The temperature could range several tens ° C within a short time and the water availability is usually very limited. Due to temperature variation, the lichens are subjected to many freeze/thaw cycles. Such environments could be found in Martian deserts. The lichens are symbotic organisms composed of a mycobiont (heterotrophic fungi) and photo-bionts (algae and/or cyanobacteria). Majority of lichens are dehydrated in the field

  18. 40 CFR 725.85 - Microorganism identity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Microorganism identity. 725.85 Section... ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.85 Microorganism identity. (a) Claims applicable to the period prior...

  19. 40 CFR 725.85 - Microorganism identity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Microorganism identity. 725.85 Section... ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.85 Microorganism identity. (a) Claims applicable to the period prior...

  20. 40 CFR 725.85 - Microorganism identity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Microorganism identity. 725.85 Section... ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.85 Microorganism identity. (a) Claims applicable to the period prior...

  1. 40 CFR 725.85 - Microorganism identity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Microorganism identity. 725.85 Section... ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.85 Microorganism identity. (a) Claims applicable to the period prior...

  2. 40 CFR 725.85 - Microorganism identity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Microorganism identity. 725.85 Section... ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.85 Microorganism identity. (a) Claims applicable to the period prior...

  3. Predatory Microorganisms Would Help Reclaim Water

    NASA Technical Reports Server (NTRS)

    Benjaminson, Morris A.; Lehrer, Stanley

    1995-01-01

    Wastewater-reclamation systems of proposed type use predatory, nonpathogenic microorganisms to consume pathogenic microorganisms. Unlike some other wastewater-reclamation systems, these systems do not require use of toxic chemicals, intense heat, or ionizing radiation (conductivity rays or ultraviolet) to destroy microorganisms.

  4. Presidential Green Chemistry Challenge: 2005 Small Business Award

    EPA Pesticide Factsheets

    Presidential Green Chemistry Challenge 2005 award winner, Metabolix, used biotechnology to develop microorganisms that produce polyhydroxyalkanoates: natural, biodegradable plastics with a range of environmental benefits.

  5. Characterization of a salt-tolerant family 42 beta-galactosidase from a psychrophilic antarctic Planococcus isolate.

    PubMed

    Sheridan, P P; Brenchley, J E

    2000-06-01

    We isolated a gram-positive, halotolerant psychrophile from a hypersaline pond located on the McMurdo Ice Shelf in Antarctica. A phylogenetic analysis of the 16S rRNA gene sequence of this organism showed that it is a member of the genus Planococcus. This assignment is consistent with the morphology and physiological characteristics of the organism. A gene encoding a beta-galactosidase in this isolate was cloned in an Escherichia coli host. Sequence analysis of this gene placed it in glycosidase family 42 most closely related to an enzyme from Bacillus circulans. Even though an increasing number of family 42 glycosidase sequences are appearing in databases, little information about the biochemical features of these enzymes is available. Therefore, we purified and characterized this enzyme. The purified enzyme did not appear to have any metal requirement, had an optimum pH of 6.5 and an optimum temperature of activity at 42 degrees C, and was irreversibly inactivated within 10 min when it was incubated at 55 degrees C. The enzyme had an apparent K(m) of 4.9 micromol of o-nitrophenyl-beta-D-galactopyranoside, and the V(max) was 467 micromol of o-nitrophenol produced/min/mg of protein at 39 degrees C. Of special interest was the finding that the enzyme remained active at high salt concentrations, which makes it a possible reporter enzyme for halotolerant and halophilic organisms.

  6. Structure prediction of Fe(II) 2-oxoglutarate dioxygenase from a psychrophilic yeast Glaciozyma antarctica PI12

    NASA Astrophysics Data System (ADS)

    Yusof, Nik Yusnoraini; Bakar, Farah Diba Abu; Mahadi, Nor Muhammad; Raih, Mohd Firdaus; Murad, Abdul Munir Abdul

    2015-09-01

    A cDNA encoding Fe(II) 2-oxoglutarate (2OG) dependent dioxygenases was isolated from psychrophilic yeast, Glaciozyma antarctica PI12. We have successfully amplified 1,029 bp cDNA sequence that encodes 342 amino acid with predicted molecular weight 38 kDa. The prediction protein was analysed using various bioinformatics tools to explore the properties of the protein. Based on a BLAST search analysis, the Fe2OX amino acid sequence showed 61% identity to the sequence of oxoglutarate/iron-dependent oxygenase from Rhodosporidium toruloides NP11. SignalP prediction showed that the Fe2OX protein contains no putative signal peptide, which suggests that this enzyme most probably localised intracellularly.The structure of Fe2OX was predicted by homology modelling using MODELLER9v11. The model with the lowest objective function was selected from hundred models generated using MODELLER9v11. Analysis of the structure revealed the longer loop at Fe2OX from G.antarctica that might be responsible for the flexibility of the structure, which contributes to its adaptation to low temperatures. Fe2OX hold a highly conserved Fe(II) binding HXD/E…H triad motif. The binding site for 2-oxoglutarate was found conserved for Arg280 among reported studies, however the Phe268 was found to be different in Fe2OX.

  7. Spectroscopic analyses of manganese ions effects on the conformational changes of inorganic pyrophosphatase from psychrophilic Shewanella sp. AS-11.

    PubMed

    Ginting, Elvy Like; Maeganeku, Chihiro; Motoshima, Hiroyuki; Watanabe, Keiichi

    2014-02-01

    Mn²⁺ ions influence the activity, temperature dependence, and thermostability of the psychrophilic Shewanella-PPase (Sh-PPase), and are required to function in cold environments. The functional characteristics of Sh-PPase on activation with Mn²⁺ ions are possibly related to conformational changes in the molecule. In this study, conformational changes of Sh-PPase on activation with Mn²⁺ ions were analyzed in solution by fluorescence spectroscopy analysis of intrinsic tryptophan residues, 1-anilino-8-naphthalene sulfonate fluorescence, and circular dichroism spectroscopy. For Sh-PPase, Mn²⁺ ions did not affect the flexibility of the tryptophan residues and secondary structure of the enzyme. However, the microenvironment of the tryptophan residues and surface area of Sh-PPase were more hydrophilic on activation with Mn²⁺ ions. These results indicate that activation with Mn²⁺ ions causes conformational changes around the aromatic amino acid residues and affects the hydrophobicity of the enzyme surface, which results in conformational changes. Substrate-induced conformational changes reflect that metal-free Sh-PPase in solution indicated an open structure and will be a close structure when binding substrate. In combination of our spectroscopic analyses on Sh-PPase, it can be concluded that activation with Mn²⁺ ions changes some conformation of Sh-PPase molecule in solution.

  8. Desulfuromonas svalbardensis sp. nov. and Desulfuromusa ferrireducens sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard.

    PubMed

    Vandieken, Verona; Mussmann, Marc; Niemann, Helge; Jørgensen, Bo Barker

    2006-05-01

    Two psychrophilic, Gram-negative, rod-shaped, motile bacteria (strains 112T and 102T) that conserved energy from dissimilatory Fe(III) reduction concomitant with acetate oxidation were isolated from permanently cold Arctic marine sediments. Both strains grew at temperatures down to -2 degrees C, with respective temperature optima of 14 degrees C and 14-17 degrees C for strains 112T and 102T. The isolated strains reduced Fe(III) using common fermentation products such as acetate, lactate, propionate, formate or hydrogen as electron donors, and they also grew with fumarate as the sole substrate. As alternatives to Fe(III), they reduced fumarate, S0 and Mn(IV). Based on 16S rRNA gene sequence similarity, strain 112T was most closely related to Desulfuromonas acetoxidans (97.0 %) and Desulfuromonas thiophila NZ27T (95.5 %), and strain 102T to Malonomonas rubra Gra Mal 1T (96.3 %) and Desulfuromusa succinoxidans GylacT (95.9 %) within the Deltaproteobacteria. Strains 112T and 102T therefore represent novel species, for which the names Desulfuromonas svalbardensis sp. nov. (type strain 112T=DSM 16958T=JCM 12927T) and Desulfuromusa ferrireducens sp. nov. (type strain 102T=DSM 16956T=JCM 12926T) are proposed.

  9. Production of cryoprotectant extracellular polysaccharide substances (EPS) by the marine psychrophilic bacterium Colwellia psychrerythraea strain 34H under extreme conditions.

    PubMed

    Marx, Joseph G; Carpenter, Shelly D; Deming, Jody W

    2009-01-01

    Extracellular polysaccharide substances (EPS) play critical roles in microbial ecology, including the colonization of extreme environments in the ocean, from sea ice to the deep sea. After first developing a sugar-free growth medium, we examined the relative effects of temperature, pressure, and salinity on EPS production (on a per cell basis) by the obligately marine and psychrophilic gamma-proteobacterium, Colwellia psychrerythraea strain 34H. Over growth-permissive temperatures of approximately 10 to -4 degrees C, EPS production did not change, but from -8 to -14 degrees C when samples froze, EPS production rose dramatically. Similarly, at growth-permissive hydrostatic pressures of 1-200 atm (1 atm = 101.325 kPa) (at -1 and 8 degrees C), EPS production was unchanged, but at higher pressures of 400 and 600 atm EPS production rose markedly. In salinity tests at 10-100 parts per million (and -1 and 5 degrees C), EPS production increased at the freshest salinity tested. Extreme environmental conditions thus appear to stimulate EPS production by this strain. Furthermore, strain 34H recovered best from deep-freezing to -80 degrees C (not found for Earthly environments) if first supplemented with a preparation of its own EPS, rather than other cryoprotectants like glycerol, suggesting EPS production as both a survival strategy and source of compounds with potentially novel properties for biotechnological and other applications.

  10. In silico analysis of β-1,3-glucanase from a psychrophilic yeast, Glaciozyma antarctica PI12

    NASA Astrophysics Data System (ADS)

    Mohammadi, Salimeh; Bakar, Farah Diba Abu; Rabu, Amir; Murad, Abdul Munir Abdul

    2014-09-01

    1,3-beta-glucanase is an industrially important enzyme having wide range of applications especially in food industry. It is crucial to gain an understanding about the structure and functional aspects of various beta-1,3-glucanase produced from diverse sources. In this, study a cDNA encoding β-1,3-glucanase (GaExg55) was isolated from a psychrophilic yeast, Glaciozyma antarctica PI12. The cDNA sequence has been submitted to Genbank with an accession number (KJ436377). Subsequently, the perdition protein was analyzed using various bioinformatics tools to explore the properties of the protein. GaEXG55 is consisting of 1,440-bp nucleotides encoding 480 amino acid residues. Alignment of the deduced amino acid for GaExg55 with other exo-β-1,3-glucanase available at the NCBI database indicate that deduced amino acids shared a consensus motif NEP, which is signature pattern of GH5 hydrolases. Predicted molecular weight of GaExg55 is 53.66 kDa. GaExg55 sequences possesses signal peptide sequence and it is highly conserved with other fungal exo-beta-1,3 glucanase.

  11. Cytoplasmic and Periplasmic Proteomic Signatures of Exponentially Growing Cells of the Psychrophilic Bacterium Pseudoalteromonas haloplanktis TAC125 ▿ †

    PubMed Central

    Wilmes, Boris; Kock, Holger; Glagla, Susanne; Albrecht, Dirk; Voigt, Birgit; Markert, Stephanie; Gardebrecht, Antje; Bode, Rüdiger; Danchin, Antoine; Feller, Georges; Hecker, Michael; Schweder, Thomas

    2011-01-01

    The psychrophilic model bacterium Pseudoalteromonas haloplanktis is characterized by remarkably fast growth rates under low-temperature conditions in a range from 5°C to 20°C. In this study the proteome of cellular compartments, the cytoplasm and periplasm, of P. haloplanktis strain TAC125 was analyzed under exponential growth conditions at a permissive temperature of 16°C. By means of two-dimensional protein gel electrophoresis and mass spectrometry, a first inventory of the most abundant cytoplasmic and periplasmic proteins expressed in a peptone-supplemented minimal medium was established. By this approach major enzymes of the amino acid catabolism of this marine bacterium could be functionally deduced. The cytoplasmic proteome showed a predominance of amino acid degradation pathways and tricarboxylic acid (TCA) cycle enzymes but also the protein synthesis machinery. Furthermore, high levels of cold acclimation and oxidative stress proteins could be detected at this moderate growth temperature. The periplasmic proteome was characterized by a significant abundance of transporters, especially of highly expressed putative TonB-dependent receptors. This high capacity for protein synthesis, efficient amino acid utilization, and substrate transport may contribute to the fast growth rates of the copiotrophic bacterium P. haloplanktis in its natural environments. PMID:21183643

  12. Dioszegia antarctica sp. nov. and Dioszegia cryoxerica sp. nov., psychrophilic basidiomycetous yeasts from polar desert soils in Antarctica

    USGS Publications Warehouse

    Rodriguez, Russell J.; Connell, L.; Redman, R.; Barrett, A.; Iszard, M.; Fonseca, A.

    2010-01-01

    During a survey of the culturable soil fungal population in samples collected in Taylor Valley, South Victoria Land, Antarctica, 13 basidiomycetous yeast strains with orange-coloured colonies were isolated. Phylogenetic analyses of internal transcribed spacer (ITS) and partial LSU rRNA gene sequences showed that the strains belong to the Dioszegia clade of the Tremellales (Tremellomycetes, Agaricomycotina), but did not correspond to any of the hitherto recognized species. Two novel species, Dioszegia antarctica sp. nov. (type strain ANT-03-116T =CBS 10920T =PYCC 5970T) and Dioszegia cryoxerica sp. nov. (type strain ANT-03-071T =CBS 10919T =PYCC 5967T), are described to accommodate ten and three of these strains, respectively. Analysis of ITS sequences demonstrated intrastrain sequence heterogeneity in D. cryoxerica. The latter species is also notable for producing true hyphae with clamp connections and haustoria. However, no sexual structures were observed. The two novel species can be considered obligate psychrophiles, since they failed to grow above 20 °C and grew best between 10 and 15 °C.

  13. Rapid Detection of Microorganisms--State of Art and Future Directions

    NASA Astrophysics Data System (ADS)

    Hong, George

    2008-03-01

    For the last several decades, nutrient-based culture growth methods have been accepted as the standard for microorganism detection and identification. However, since the discovery of nucleic acids and molecular breakthrough technologies such as restriction enzymes and polymerase chain reactions, the detection and identification of microorganisms have advanced to culture-independent methods that fall under the category of rapid microbial detections. Here, we present an overview of major rapid microbial detection technologies. These technologies will include both amplification and non-amplification based methods for the detection and identification of target microorganisms. The technologies described can be applied to detecting a wide variety of microorganisms, including bacteria, viruses, mycoplasma, and fungi and have the potential sensitivity to detect a single microorganism. Also in this presentation, we will present examples of real-life applications as well as future challenges for the advancement of the field of rapid microbiology.

  14. Cellulolytic Microorganisms from Thermal Environments

    SciTech Connect

    Vishnivetskaya, Tatiana A; Raman, Babu; Phelps, Tommy Joe; Podar, Mircea; Elkins, James G

    2012-01-01

    Thermal, anaerobic environments rich in decaying plant material are a potential source of novel cellulolytic bacteria. Samples collected from geothermal aquifers in the Yellowstone National Park (YNP) were used to select for cellulolytic thermophiles. Laboratory enrichments on dilute-acid pretreated plant biomass (switchgrass, Populus), and crystalline cellulose (Avicel) resulted in the isolation of 247 environmental clones. The majority of individual clones were affiliated with the cellulolytic bacteria of phylum Firmicutes, followed by xylanolytic and saccharolytic members of the phylum Dictyoglomi. Among the Firmicutes, the clones were affiliated with the genera Caldicellulosiruptor (54.4%), Caloramator (11.5%), Thermoanaerobacter (8.8%), Thermovenabulum (4.1%), and Clostridium (2.0%). From established anaerobic thermophilic enrichments a total of 81 single strains of the genera Caldicellulosiruptor (57%) and Thermoanaerobacter (43%) were isolated. With continuous flow enrichment on Avicel, increases in the relative abundance of Caloramator sp. was observed over clones detected from the Caldicellulosiruptor. Complex communities of interacting microorganisms bring about cellulose decomposition in nature, therefore using up-to-date approaches may yield novel cellulolytic microorganisms with high activity and a rapid rate of biomass conversion to biofuels.

  15. The impact of permafrost-associated microorganisms on hydrate formation kinetics

    NASA Astrophysics Data System (ADS)

    Luzi-Helbing, Manja; Liebner, Susanne; Spangenberg, Erik; Wagner, Dirk; Schicks, Judith M.

    2016-04-01

    The relationship between gas hydrates, microorganisms and the surrounding sediment is extremely complex: On the one hand, microorganisms producing methane provide the prerequisite for gas hydrate formation. As it is known most of the gas incorporated into natural gas hydrates originates from biogenic sources. On the other hand, as a result of microbial activity gas hydrates are surrounded by a great variety of organic compounds which are not incorporated into the hydrate structure but may influence the formation or degradation process. For gas hydrate samples from marine environments such as the Gulf of Mexico a direct association between microbes and gas hydrates was shown by Lanoil et al. 2001. It is further assumed that microorganisms living within the gas hydrate stability zone produce biosurfactants which were found to enhance the hydrate formation process significantly and act as nucleation centres (Roger et al. 2007). Another source of organic compounds is sediment organic matter (SOM) originating from plant material or animal remains which may also enhance hydrate growth. So far, the studies regarding this relationship were focused on a marine environment. The scope of this work is to extend the investigations to microbes originating from permafrost areas. To understand the influence of microbial activity in a permafrost environment on the methane hydrate formation process and the stability conditions of the resulting hydrate phase we will perform laboratory studies. Thereby, we mimic gas hydrate formation in the presence and absence of methanogenic archaea (e.g. Methanosarcina soligelidi) and other psychrophilic bacteria isolated from permafrost environments of the Arctic and Antarctic to investigate their impact on hydrate induction time and formation rates. Our results may contribute to understand and predict the occurrences and behaviour of potential gas hydrates within or adjacent to the permafrost. Lanoil BD, Sassen R, La Duc MT, Sweet ST, Nealson KH

  16. Tarnish of dental alloys by oral microorganisms.

    PubMed

    Vaidyanathan, T K; Vaidyanathan, J; Linke, H A; Schulman, A

    1991-11-01

    Five dental alloys, on exposure to blood and chocolate media with and without inoculated microorganisms, showed varying degrees of tarnish. The results indicated a composition-dependent tarnish behavior of alloys in microorganism-inoculated media, indicating a potential role for the oral microorganisms in inducing clinically observed tarnish of dental alloys. Actinomyces viscosus and periodontal pocket specimens show a similarity in their activity to induce tarnish in base metal-containing dental alloys.

  17. Functional Basis of Microorganism Classification.

    PubMed

    Zhu, Chengsheng; Delmont, Tom O; Vogel, Timothy M; Bromberg, Yana

    2015-08-01

    Correctly identifying nearest "neighbors" of a given microorganism is important in industrial and clinical applications where close relationships imply similar treatment. Microbial classification based on similarity of physiological and genetic organism traits (polyphasic similarity) is experimentally difficult and, arguably, subjective. Evolutionary relatedness, inferred from phylogenetic markers, facilitates classification but does not guarantee functional identity between members of the same taxon or lack of similarity between different taxa. Using over thirteen hundred sequenced bacterial genomes, we built a novel function-based microorganism classification scheme, functional-repertoire similarity-based organism network (FuSiON; flattened to fusion). Our scheme is phenetic, based on a network of quantitatively defined organism relationships across the known prokaryotic space. It correlates significantly with the current taxonomy, but the observed discrepancies reveal both (1) the inconsistency of functional diversity levels among different taxa and (2) an (unsurprising) bias towards prioritizing, for classification purposes, relatively minor traits of particular interest to humans. Our dynamic network-based organism classification is independent of the arbitrary pairwise organism similarity cut-offs traditionally applied to establish taxonomic identity. Instead, it reveals natural, functionally defined organism groupings and is thus robust in handling organism diversity. Additionally, fusion can use organism meta-data to highlight the specific environmental factors that drive microbial diversification. Our approach provides a complementary view to cladistic assignments and holds important clues for further exploration of microbial lifestyles. Fusion is a more practical fit for biomedical, industrial, and ecological applications, as many of these rely on understanding the functional capabilities of the microbes in their environment and are less concerned with

  18. Biocorrosion produced by Thiobacillus-like microorganisms.

    PubMed

    López, A I; Marín, I; Amils, R

    1994-01-01

    Biocorrosion can be produced by many different microorganisms through diverse mechanisms. The biocorrosion produced by acidophilic microorganisms of the genus Thiobacillus is based on the production of sulfuric acid and ferric ion from pyrites or related mineral structures, as a result of the chemolithotrophic metabolism of these microorganisms. The products of this aerobic respiration are also powerful oxidant elements, which can produce chemical oxidations of other metallic structures. The Tinto River, a very unusual extremophilic habitat (pH around 2, and high concentration of ferric ion), product of the growth of strict chemolithotrophic microorganisms, is discussed as a model case.

  19. Plants and microorganisms as drivers of mineral weathering

    NASA Astrophysics Data System (ADS)

    Dontsova, K.; Chorover, J.; Maier, R.; Hunt, E.; Zaharescu, D. G.

    2011-12-01

    Plants and microorganisms play important role in mineral weathering and soil formation modifying their environment to make it more hospitable for life. This presentation summarizes several collaborative studies that focused on understanding how interactions between plants and microorganisms, where plants provide the energy through photosynthesis, drive mineral weathering and result in soil formation. Plants influence weathering through multiple mechanisms that have been previously established, such as increase in CO2 concentration in the soil through root respiration and degradation of plant residues and exudates by heterotrophic microorganisms, release of organic acids that promote mineral dissolution, removal of weathering products from soil solution through uptake, and water redistribution. Weathering processes result in nutrient release that satisfies immediate needs of the plants and microorganisms, as well as precipitation of secondary phases, that provide surfaces for retention of nutrients and organic carbon accumulation. What makes understanding contribution of plants and microorganisms, such as bacteria and fungi, to mineral weathering challenging is the fact that they closely interact, enhancing and amplifying each other's contribution. In order to address multiple processes that contribute to and result from biological weathering a combination of chemical, biological, mineralogical, and computational techniques and methodologies is needed. This complex array of methodologies includes bulk techniques, such as determination of total dissolved organic and inorganic carbon and nitrogen, ion chromatography and high performance liquid chromatography to characterize amount and composition of exuded organic acids, inductively coupled plasma mass spectrometry to determine concentrations of lithogenic elements in solution, X-ray diffraction to characterize changes in mineral composition of the material, DNA extraction to characterize community structure, as well

  20. Rapidly evolving microorganisms with high biofuel tolerance

    NASA Astrophysics Data System (ADS)

    Vyawahare, Saurabh; Zhang, Qiucen; Lang, Wendy; Austin, Robert

    2012-02-01

    Replacing non-renewable energy sources is one of the biggest and most exciting challenges of our generation. Algae and bacteria are poised to become major renewable biofuels if strains can be developed that provide a high,consistent and robust yield of oil. One major stumbling block towards this goal is the lack of tolerance to high concentrations of biofuels like isobutanol. Using traditional bioengineering techniques to remedy this face the hurdle of identifying the correct pathway or gene to modify. But the multiplicity of interactions inside a cell makes it very hard to determine what to modify a priori. Instead, we propose a technology that does not require prior knowledge of the genes or pathways to modify. In our approach that marries microfabrication and ecology, spatial heterogeneity is used as a knob to speed up evolution in the desired direction. Recently, we have successfully used this approach to demonstrate the rapid emergence of bacterial antibiotic resistance in as little as ten hours. Here, we describe our experimental results in developing new strains of micro-organisms with high oil tolerance. Besides biofuel production, our work is also relevant to oil spill clean-ups.

  1. New subgroup of Bacteroidetes and diverse microorganisms in Tibetan plateau glacial ice provide a biological record of environmental conditions.

    PubMed

    Zhang, Xiaojun; Ma, Xiaojun; Wang, Ninglian; Yao, Tandong

    2009-01-01

    We recovered microorganisms from five ice core samples from three glaciers (Puruogangri, Malan, and Dunde) located in the Tibetan Plateau in China and analyzed their small subunit rRNA gene sequences. Most of the bacterial sequences were unknown previously; the most closely related known sequences were from bacteria of the Proteobacteria, Bacteroidetes, and Actinobacteria phyla. Chlorophyta, Streptophyta, Ciliophora, and fungal groups were represented among the 18S rRNA gene sequences that we obtained. The most abundantly represented glacial bacteria were Bacteroidetes, and Chlamydomonas was the predominant eukaryote. Comparative analysis showed that the Bacteroidetes sequences obtained from this study were highly similar to one another but most were only distantly related to previously characterized Bacteroidetes (<92% identity). We propose that our Bacteroidetes sequences represent two novel subgroups: one at the family level and one at the genus level. The unique ice environment and the high abundance of Bacteroidetes, combined with the coexistence of a high abundance of psychrophilic Chlamydomonas, strongly suggests that there is a viable ecosystem on the surface of Tibetan glaciers. Comparisons of microbial community structures in the five ice samples showed distinct differences, likely due to environmental differences in the locations in which the samples were obtained.

  2. Expression and characterization of a recombinant psychrophilic Cu/Zn superoxide dismutase from Deschampsia antarctica E. Desv. [Poaceae].

    PubMed

    Rojas-Contreras, Juan A; de la Rosa, Ana P Barba; De León-Rodríguez, Antonio

    2015-04-01

    We present here the structural modeling and biochemical characterization of a recombinant superoxide dismutase (SOD) from Deschampsia antarctica E. Desv. [Poaceae] produced in Escherichia coli. The recombinant protein was purified by affinity chromatography nickel-nitrilotriacetic acid (Ni-NTA), and its identity was demonstrated by immunoblotting and inhibition by H2O2 and KCN. Inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis confirmed the presence of Cu and Zn. Modeling of the D. antarctica Cu/Zn-SOD (DaSOD) amino acid sequence using the SWISS-MODEL and 2Q2L_B monomer of the psychrophilic Cu/Zu-SOD from Potentilla atrosanguinea (PaSOD) as template produced a structure similar to that of the typical eukaryotic Cu/Zn-SODs. Activity assays using the p-nitro blue tetrazolium chloride (NBT) solution method showed that the purified DaSOD had a specific activity of 5818 U/mg at 25 °C and pH 7.2 and that it was active in a pH interval of 5-8 and a temperature interval of 0-40 °C. Furthermore, DaSOD was still active at -20 °C as observed by a zymogram assay. We found 100 % activity when it was heated at 80 °C for 60 min, indicating a high thermostability. DaSOD properties suggest that this enzyme could be useful for preventing the oxidation of refrigerated or frozen foods, as well as in the preparation of cosmetic and pharmaceutical products.

  3. UV Radiation and Visible Light Induce hsp70 Gene Expression in the Antarctic Psychrophilic Ciliate Euplotes focardii.

    PubMed

    Fulgentini, Lorenzo; Passini, Valerio; Colombetti, Giuliano; Miceli, Cristina; La Terza, Antonietta; Marangoni, Roberto

    2015-08-01

    The psychrophilic ciliate Euplotes focardii inhabits the shallow marine coastal sediments of Antarctica, where, over millions of years of evolution, it has reached a strict molecular adaptation to such a constant-temperature environment (about -2 °C). This long evolution at sub-zero temperatures has made E. focardii unable to respond to heat stress with the activation of its heat shock protein (hsp) 70 genes. These genes can, however, be expressed in response to other stresses, like the oxidative one, thus indicating that the molecular adaptation has exclusively altered the heat stress signaling pathways, while it has preserved hsp70 gene activation in response to other environmental stressors. Since radiative stress has proved to be affine to oxidative stress in several organisms, we investigated the capability of UV radiation to induce hsp70 transcription. E. focardii cell cultures were exposed to several different irradiation regimes, ranging from visible only to a mixture of visible, UV-A and UV-B. The irradiation values of each spectral band have been set to be comparable with those recorded in a typical Antarctic spring. Using Northern blot analysis, we measured the expression level of hsp70 immediately after irradiation (0-h-labeled samples), 1 h, and 2 h from the end of the irradiation. Surprisingly, our results showed that besides UV radiation, the visible light was also able to induce hsp70 expression in E. focardii. Moreover, spectrophotometric measurements have revealed no detectable endogenous pigments in E. focardii, making it difficult to propose a possible explanation for the visible light induction of its hsp70 genes. Further research is needed to conclusively clarify this point.

  4. Desulfoconvexum algidum gen. nov., sp. nov., a psychrophilic sulfate-reducing bacterium isolated from a permanently cold marine sediment.

    PubMed

    Könneke, Martin; Kuever, Jan; Galushko, Alexander; Jørgensen, Bo Barker

    2013-03-01

    A sulfate-reducing bacterium, designated JHA1(T), was isolated from a permanently cold marine sediment sampled in an Artic fjord on the north-west coast of Svalbard. The isolate was originally enriched at 4 °C in a highly diluted liquid culture amended with hydrogen and sulfate. Strain JHA1(T) was a psychrophile, growing fastest between 14 and 16 °C and not growing above 20 °C. Fastest growth was found at neutral pH (pH 7.2-7.4) and at marine concentrations of NaCl (20-30 g l(-1)). Phylogenetic analysis of 16S rRNA gene sequences revealed that strain JHA1(T) was a member of the family Desulfobacteraceae in the Deltaproteobacteria. The isolate shared 99 % 16S rRNA gene sequence similarity with an environmental sequence obtained from permanently cold Antarctic sediment. The closest recognized relatives were Desulfobacula phenolica DSM 3384(T) and Desulfobacula toluolica DSM 7467(T) (both <95 % sequence similarity). In contrast to its closest phylogenetic relatives, strain JHA1(T) grew chemolithoautotrophically with hydrogen as an electron donor. CO dehydrogenase activity indicated the operation of the reductive acetyl-CoA pathway for inorganic carbon assimilation. Beside differences in physiology and morphology, strain JHA1(T) could be distinguished chemotaxonomically from the genus Desulfobacula by the absence of the cellular fatty acid C16 : 0 10-methyl. Phylogenetic differentiation from other genera was further supported by DsrAB and AprBA sequence analysis. Based on the described phylogenetic and phenotypic differences between strain JHA1(T) and its closest relatives, the establishment of a novel genus and a novel species, Desulfoconvexum algidum gen. nov., sp. nov. is proposed. The type strain is JHA1(T) ( = DSM 21856(T)  = JCM 16085(T)).

  5. The Antarctic Psychrophile Chlamydomonas sp. UWO 241 Preferentially Phosphorylates a Photosystem I-Cytochrome b6/f Supercomplex.

    PubMed

    Szyszka-Mroz, Beth; Pittock, Paula; Ivanov, Alexander G; Lajoie, Gilles; Hüner, Norman P A

    2015-09-01

    Chlamydomonas sp. UWO 241 (UWO 241) is a psychrophilic green alga isolated from Antarctica. A unique characteristic of this algal strain is its inability to undergo state transitions coupled with the absence of photosystem II (PSII) light-harvesting complex protein phosphorylation. We show that UWO 241 preferentially phosphorylates specific polypeptides associated with an approximately 1,000-kD pigment-protein supercomplex that contains components of both photosystem I (PSI) and the cytochrome b₆/f (Cyt b₆/f) complex. Liquid chromatography nano-tandem mass spectrometry was used to identify three major phosphorylated proteins associated with this PSI-Cyt b₆/f supercomplex, two 17-kD PSII subunit P-like proteins and a 70-kD ATP-dependent zinc metalloprotease, FtsH. The PSII subunit P-like protein sequence exhibited 70.6% similarity to the authentic PSII subunit P protein associated with the oxygen-evolving complex of PSII in Chlamydomonas reinhardtii. Tyrosine-146 was identified as a unique phosphorylation site on the UWO 241 PSII subunit P-like polypeptide. Assessment of PSI cyclic electron transport by in vivo P700 photooxidation and the dark relaxation kinetics of P700(+) indicated that UWO 241 exhibited PSI cyclic electron transport rates that were 3 times faster and more sensitive to antimycin A than the mesophile control, Chlamydomonas raudensis SAG 49.72. The stability of the PSI-Cyt b₆/f supercomplex was dependent upon the phosphorylation status of the PsbP-like protein and the zinc metalloprotease FtsH as well as the presence of high salt. We suggest that adaptation of UWO 241 to its unique low-temperature and high-salt environment favors the phosphorylation of a PSI-Cyt b₆/f supercomplex to regulate PSI cyclic electron transport rather than the regulation of state transitions through the phosphorylation of PSII light-harvesting complex proteins.

  6. Genome Sequence of Rhodoferax antarcticus ANT.BRT; A Psychrophilic Purple Nonsulfur Bacterium from an Antarctic Microbial Mat

    PubMed Central

    Baker, Jennifer M.; Riester, Carli J.; Skinner, Blair M.; Newell, Austin W.; Swingley, Wesley D.; Madigan, Michael T.; Jung, Deborah O.; Asao, Marie; Chen, Min; Loughlin, Patrick C.; Pan, Hao; Lin, Yuankui; Li, Yaqiong; Shaw, Jacob; Prado, Mindy; Sherman, Chris; Tang, Joseph Kuo-Hsiang; Blankenship, Robert E.; Zhao, Tingting; Touchman, Jeffrey W.; Sattley, W. Matthew

    2017-01-01

    Rhodoferax antarcticus is an Antarctic purple nonsulfur bacterium and the only characterized anoxygenic phototroph that grows best below 20 °C. We present here a high-quality draft genome of Rfx. antarcticus strain ANT.BRT, isolated from an Antarctic microbial mat. The circular chromosome (3.8 Mbp) of Rfx. antarcticus has a 59.1% guanine + cytosine (GC) content and contains 4036 open reading frames. In addition, the bacterium contains a sizable plasmid (198.6 kbp, 48.4% GC with 226 open reading frames) that comprises about 5% of the total genetic content. Surprisingly, genes encoding light-harvesting complexes 1 and 3 (LH1 and LH3), but not light-harvesting complex 2 (LH2), were identified in the photosynthesis gene cluster of the Rfx. antarcticus genome, a feature that is unique among purple phototrophs. Consistent with physiological studies that showed a strong capacity for nitrogen fixation in Rfx. antarcticus, a nitrogen fixation gene cluster encoding a molybdenum-type nitrogenase was present, but no alternative nitrogenases were identified despite the cold-active phenotype of this phototroph. Genes encoding two forms of ribulose 1,5-bisphosphate carboxylase/oxygenase were present in the Rfx. antarcticus genome, a feature that likely provides autotrophic flexibility under varying environmental conditions. Lastly, genes for assembly of both type IV pili and flagella are present, with the latter showing an unusual degree of clustering. This report represents the first genomic analysis of a psychrophilic anoxygenic phototroph and provides a glimpse of the genetic basis for maintaining a phototrophic lifestyle in a permanently cold, yet highly variable, environment. PMID:28230808

  7. [Granulomatous diseases and pathogenic microorganism].

    PubMed

    Inoue, Yoshikazu; Suga, Moritaka

    2008-02-01

    Granuloma formation is a chronic inflammatory reaction where macrophage system and other inflammatory cells are involved. After some antigen exposure and processing, T cells, macrophages, epithelioid cells, and giant cell are activated, and granulomas are formed. Granuloma is considered as a defense mechanism against antigens, which stay in the organs without inactivation. Granulomas including fibroblasts extra-cellular matrix surround and isolate the antigens. Granulomas are classified to noninfectious granulomas and infectious granulomas. However recent studies revealed pathogenic microorganism are suspected to be a cause of granuloma in non-inflammatory diseases. Balance between pathogenic microorganisms and defense mechanisms of the host might be important in the special immunologic reaction. In some cases, it is hard to clearly classify infectious and noninfectious granulomas. Recently, Eishi et al. reported that latent infection of Propionibacterium acnes might be cause of sarcoidosis. Several hypersensitivity pneumonias are considered to be caused by exogenous microorganisms. The symposium was organized to know and clarify the new mechanisms of non-infectious granulomatous lung diseases and pathogenic microorganisms. This report is a summary of a symposium entitled "Granulomatous Diseases and Pathogenic Microorganism", organized in the 82nd Japanese Society for Tuberculosis (president Dr. Mitsunori Sakatani, M.D.). 1. Imaging of Granulomatous Lung Diseases: Masanori AKIRA (Department of Radiology, National Hospital Organization Kinki-chuo Chest Medical Center) High-resolution computed tomography (HRCT) is a useful tool in the evaluation of parenchymal changes in patients with a granulomatous lung disease. In sarcoidosis, the HRCT findings include small, well-defined nodules in relation to lymphatic roots, lymph node enlargement, and middle or upper lobe predominance. The appearances of subacute hypersensitivity pneumonitis include ill-defined centrilobular

  8. Defining the response of a microorganism to temperatures that span its complete growth temperature range (-2°C to 28°C) using multiplex quantitative proteomics.

    PubMed

    Williams, Timothy J; Lauro, Federico M; Ertan, Haluk; Burg, Dominic W; Poljak, Anne; Raftery, Mark J; Cavicchioli, Ricardo

    2011-08-01

    The growth of all microorganisms is limited to a specific temperature range. However, it has not previously been determined to what extent global protein profiles change in response to temperatures that incrementally span the complete growth temperature range of a microorganism. As a result it has remained unclear to what extent cellular processes (inferred from protein abundance profiles) are affected by growth temperature and which, in particular, constrain growth at upper and lower temperature limits. To evaluate this, 8-plex iTRAQ proteomics was performed on the Antarctic microorganism, Methanococcoides burtonii. Methanococcoides burtonii was chosen due to its importance as a model psychrophilic (cold-adapted) member of the Archaea, and the fact that proteomic methods, including subcellular fractionation procedures, have been well developed. Differential abundance patterns were obtained for cells grown at seven different growth temperatures (-2°C, 1°C, 4°C, 10°C, 16°C, 23°C, 28°C) and a principal component analysis (PCA) was performed to identify trends in protein abundances. The multiplex analysis enabled three largely distinct physiological states to be described: cold stress (-2°C), cold adaptation (1°C, 4°C, 10°C and 16°C), and heat stress (23°C and 28°C). A particular feature of the thermal extremes was the synthesis of heat- and cold-specific stress proteins, reflecting the important, yet distinct ways in which temperature-induced stress manifests in the cell. This is the first quantitative proteomic investigation to simultaneously assess the response of a microorganism to numerous growth temperatures, including the upper and lower growth temperatures limits, and has revealed a new level of understanding about cellular adaptive responses.

  9. Microorganisms detected by enzyme-catalyzed reaction

    NASA Technical Reports Server (NTRS)

    Vango, S. P.; Weetall, H. H.; Weliky, N.

    1966-01-01

    Enzymes detect the presence of microorganisms in soils. The enzyme lysozymi is used to release the enzyme catalase from the microorganisms in a soil sample. The catalase catalyzes the decomposition of added hydrogen peroxide to produce oxygen which is detected manometrically. The partial pressure of the oxygen serves as an index of the samples bacteria content.

  10. Degradation of polychlorinated biphenyls by microorganisms

    SciTech Connect

    Yagi, O.; Sudo, R.

    1980-05-01

    The biodegradation of PCB's by microorganisms and the degradation pathway of PCB's are investigated. Experimental methods and materials are described. Only several strains of bacteria, Achromobacter sp., Alcaligenes sp., Acinetobacter sp., Pseudomonas sp., and soil microorganisms were able to decompose PCB's. A possible relationships between the structure and biodegradability of related biphenyl compounds was examined. (5 diagrams, 11 graphs, 18 references, 1 table)

  11. Biofouling of marbles by oxygenic photosynthetic microorganisms.

    PubMed

    Karaca, Zeki; Öztürk, Ayten; Çolak, Emel

    2015-08-01

    Phototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.

  12. [Genome editing of industrial microorganism].

    PubMed

    Zhu, Linjiang; Li, Qi

    2015-03-01

    Genome editing is defined as highly-effective and precise modification of cellular genome in a large scale. In recent years, such genome-editing methods have been rapidly developed in the field of industrial strain improvement. The quickly-updating methods thoroughly change the old mode of inefficient genetic modification, which is "one modification, one selection marker, and one target site". Highly-effective modification mode in genome editing have been developed including simultaneous modification of multiplex genes, highly-effective insertion, replacement, and deletion of target genes in the genome scale, cut-paste of a large DNA fragment. These new tools for microbial genome editing will certainly be applied widely, and increase the efficiency of industrial strain improvement, and promote the revolution of traditional fermentation industry and rapid development of novel industrial biotechnology like production of biofuel and biomaterial. The technological principle of these genome-editing methods and their applications were summarized in this review, which can benefit engineering and construction of industrial microorganism.

  13. Psychrophilic and psychrotolerant fungi on bats and the presence of Geomyces spp. on bat wings prior to the arrival of white nose syndrome.

    PubMed

    Johnson, Lynnaun J A N; Miller, Andrew N; McCleery, Robert A; McClanahan, Rod; Kath, Joseph A; Lueschow, Shiloh; Porras-Alfaro, Andrea

    2013-09-01

    Since 2006, Geomyces destructans, the causative agent of white nose syndrome (WNS), has killed over 5.7 million bats in North America. The current hypothesis suggests that this novel fungus is an invasive species from Europe, but little is known about the diversity within the genus Geomyces and its distribution on bats in the United States. We documented the psychrophilic and psychrotolerant fungal flora of hibernating bats prior to the arrival of WNS using culture-based techniques. A total of 149 cultures, which were obtained from 30 bats in five bat hibernacula located in four caves and one mine, were sequenced for the entire internal transcribed spacer (ITS) nuclear ribosomal DNA (nrDNA) region. Approximately 53 operational taxonomic units (OTUs) at 97% similarity were recovered from bat wings, with the community dominated by fungi within the genera Cladosporium, Fusarium, Geomyces, Mortierella, Penicillium, and Trichosporon. Eleven Geomyces isolates were obtained and placed in at least seven distinct Geomyces clades based on maximum-likelihood phylogenetic analyses. Temperature experiments revealed that all Geomyces strains isolated are psychrotolerant, unlike G. destructans, which is a true psychrophile. Our results confirm that a large diversity of fungi, including several Geomyces isolates, occurs on bats prior to the arrival of WNS. Most of these isolates were obtained from damaged wings. Additional studies need to be conducted to determine potential ecological roles of these abundant Geomyces strains isolated from bats.

  14. Evolution of Arginine Biosynthesis in the Bacterial Domain: Novel Gene-Enzyme Relationships from Psychrophilic Moritella Strains (Vibrionaceae) and Evolutionary Significance of N-α-Acetyl Ornithinase

    PubMed Central

    Xu, Ying; Liang, Ziyuan; Legrain, Christianne; Rüger, Hans J.; Glansdorff, Nicolas

    2000-01-01

    In the arginine biosynthetic pathway of the vast majority of prokaryotes, the formation of ornithine is catalyzed by an enzyme transferring the acetyl group of N-α-acetylornithine to glutamate (ornithine acetyltransferase [OATase]) (argJ encoded). Only two exceptions had been reported—the Enterobacteriaceae and Myxococcus xanthus (members of the γ and δ groups of the class Proteobacteria, respectively)—in which ornithine is produced from N-α-acetylornithine by a deacylase, acetylornithinase (AOase) (argE encoded). We have investigated the gene-enzyme relationship in the arginine regulons of two psychrophilic Moritella strains belonging to the Vibrionaceae, a family phylogenetically related to the Enterobacteriaceae. Most of the arg genes were found to be clustered in one continuous sequence divergently transcribed in two wings, argE and argCBFGH(A) [“H(A)” indicates that the argininosuccinase gene consists of a part homologous to known argH sequences and of a 3′ extension able to complement an Escherichia coli mutant deficient in the argA gene, encoding N-α-acetylglutamate synthetase, the first enzyme committed to the pathway]. Phylogenetic evidence suggests that this new clustering pattern arose in an ancestor common to Vibrionaceae and Enterobacteriaceae, where OATase was lost and replaced by a deacylase. The AOase and ornithine carbamoyltransferase of these psychrophilic strains both display distinctly cold-adapted activity profiles, providing the first cold-active examples of such enzymes. PMID:10692366

  15. Draft genome sequence of Paenisporosarcina sp. strain TG-14, a psychrophilic bacterium isolated from sediment-laden stratified basal ice from Taylor Glacier, McMurdo Dry Valleys, Antarctica.

    PubMed

    Koh, Hye Yeon; Lee, Sung Gu; Lee, Jun Hyuck; Doyle, Shawn; Christner, Brent C; Kim, Hak Jun

    2012-12-01

    The psychrophilic bacterium Paenisporosarcina sp. TG-14 was isolated from sediment-laden stratified basal ice from Taylor Glacier, McMurdo Dry Valleys, Antarctica. Here we report the draft genome sequence of this strain, which may provide useful information on the cold adaptation mechanism in extremely variable environments.

  16. Draft Genome Sequence of Paenisporosarcina sp. Strain TG-14, a Psychrophilic Bacterium Isolated from Sediment-Laden Stratified Basal Ice from Taylor Glacier, McMurdo Dry Valleys, Antarctica

    PubMed Central

    Koh, Hye Yeon; Lee, Sung Gu; Lee, Jun Hyuck; Doyle, Shawn; Christner, Brent C.

    2012-01-01

    The psychrophilic bacterium Paenisporosarcina sp. TG-14 was isolated from sediment-laden stratified basal ice from Taylor Glacier, McMurdo Dry Valleys, Antarctica. Here we report the draft genome sequence of this strain, which may provide useful information on the cold adaptation mechanism in extremely variable environments. PMID:23144403

  17. Applications of Electromigration Techniques: Electromigration Techniques in Detection of Microorganisms

    NASA Astrophysics Data System (ADS)

    Dziubakiewicz, Ewelina; Buszewski, Bogusław

    The detection and identification of microbes is a challenge and an important aspect in many fields of our lives from medicine to bioterrorism defense. However, the analysis of such complex molecules brings a lot of questions mainly about their behavior. Bacteria are biocolloid, whose surface charge originates from the ionization of carboxyl, phosphate, or amino groups and the adsorption of ions from solution. Consequently, the charged cell wall groups determine the spontaneous formation of the electrical double layer. In this chapter application of electromigration techniques for microorganism's identification and separation are described. This approach represents the possibility to apply electromigration techniques in medical diagnosis, detection of food contamination, and sterility testing.

  18. Application of flow cytometry to wine microorganisms.

    PubMed

    Longin, Cédric; Petitgonnet, Clément; Guilloux-Benatier, Michèle; Rousseaux, Sandrine; Alexandre, Hervé

    2017-04-01

    Flow cytometry (FCM) is a powerful technique allowing detection and enumeration of microbial populations in food and during food process. Thanks to the fluorescent dyes used and specific probes, FCM provides information about cell physiological state and allows enumeration of a microorganism in a mixed culture. Thus, this technique is increasingly used to quantify pathogen, spoilage microorganisms and microorganisms of interest. Since one decade, FCM applications to the wine field increase greatly to determine population and physiological state of microorganisms performing alcoholic and malolactic fermentations. Wine spoilage microorganisms were also studied. In this review we briefly describe FCM principles. Next, a deep revision concerning enumeration of wine microorganisms by FCM is presented including the fluorescent dyes used and techniques allowing a yeast and bacteria species specific enumeration. Then, the last chapter is dedicated to fluorescent dyes which are used to date in fluorescent microscopy but applicable in FCM. This chapter also describes other interesting "future" techniques which could be applied to study the wine microorganisms. Thus, this review seeks to highlight the main advantages of the flow cytometry applied to wine microbiology.

  19. Marine Microorganism: An Underexplored Source of l-Asparaginase.

    PubMed

    Prihanto, A A; Wakayama, M

    2016-01-01

    l-Asparaginase (EC 3.5.1.1) is an enzyme that catalyzes the hydrolysis of l-asparagine to l-aspartic acid. This enzyme has an important role in medicine and food. l-Asparaginase is a potential drug in cancer therapy. Furthermore, it is also applied for reducing acrylamide, a carcinogenic compound in baked and fried foods. Until now, approved l-asparaginases for both applications are few due to their lack of appropriate properties. As a result, researchers have been enthusiastically seeking new sources of enzyme with better performance. A great number of terrestrial l-asparaginase-producing microorganisms have been reported but unfortunately, almost all failed to meet criteria for cancer therapy and acrylamide reducing agent. As a largest area than Earth, marine environment, by contrast, has not been optimally explored yet. So far, a great challenge facing an exploration of marine microorganisms is mainly due to their harsh, mysterious, and dangerous environment. It is clear that marine environment, a gigantic potential source for marine natural products is scantily revealed, although several approaches and technologies have been developed. This chapter presents the historical of l-asparaginase discovery and applications. It is also discussed, how the marine environment, even though offering a great potency but is still one of the less explored area for l-asparaginase-producing microorganisms.

  20. Bio-syncretic tweezers actuated by microorganisms: modeling and analysis.

    PubMed

    Zhang, C; Xie, S X; Wang, W X; Xi, N; Wang, Y C; Liu, L Q

    2016-09-28

    Advancements in micro-/nano-technology have led to the development of micro-manipulators. However, some challenges remain; for instance, the efficiency, precision and flexibility of micro-manipulators restrain their applications. This paper proposes a bio-tweezer system to flexibly manipulate micro-objects with bio-actuation via local light-induced high-concentration microorganisms in two different manipulation modes: light-spot induced mode and geometric shape-induced mode. Depending on the shape of micro-objects, either 2-dimensional translation or 1-dimensional rotation can be achieved. Based on the Langevin equation, a mathematical model considering both hydrodynamics and mimicked Brownian motion is proposed to analyze the bio-manipulation performance of the microorganisms; the model was validated by experiments to translate micro-particles in a two-dimensional plane and to rotate a micro-gear structure around its axis. This paper will aid in the development of micro-manipulators and the quantitative understanding of micro-/nano-manipulation actuated by microorganisms.

  1. Lacinutrix himadriensis sp. nov., a psychrophilic bacterium isolated from a marine sediment, and emended description of the genus Lacinutrix.

    PubMed

    Srinivas, T N R; Prasad, S; Manasa, P; Sailaja, B; Begum, Z; Shivaji, S

    2013-02-01

    A novel gram-negative, rod-shaped, non-motile, psychrophilic bacterium, designated strain E4-9a(T), was isolated from a marine sediment sample collected at a depth of 276 m from Kongsfjorden, Svalbard, in the Arctic Ocean. The colony colour was golden yellow. Strain E4-9a(T) was positive for amylase activity at 5 °C. The predominant fatty acids were iso-C(15 : 1) G (21.8 %), anteiso-C(15 : 0) (19.1 %), anteiso-C(15 : 1) A (18.6 %), iso-C(15 : 0) (13.8 %) and iso-C(16 : 1) H (6.4 %). Strain E4-9a(T) contained MK-6 as the major respiratory quinone. The polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids (AL1, AL4 and AL5), an unidentified phospholipid and four unidentified lipids (L1, L4 to L6). Based on 16S rRNA gene sequence similarity, it was ascertained that the closest related species to E4-9a(T) were Lacinutrix copepodicola, L. algicola and L. mariniflava, with sequence similarity to the respective type strains of 98.5, 96.5 and 95.8 %. Phylogenetic analysis showed that strain E4-9a(T) clustered with the type strain of L. copepodicola and with those of L. algicola and L. mariniflava at distances of 1.5 and 4.8 % (98.5 and 95.2 % similarity), respectively. However, DNA-DNA hybridization with L. copepodicola DJ3(T) showed 59 % relatedness with respect to strain E4-9a(T). The DNA G+C content of strain E4-9a(T) was 29 mol%. Based on the results of DNA-DNA hybridization and phenotypic data, it appears that strain E4-9a(T) represents a novel species of the genus Lacinutrix, for which the name Lacinutrix himadriensis sp. nov. is proposed. The type strain is E4-9a(T) ( = CIP 110310(T)  = KCTC 23612(T)).

  2. The quest for industrial enzymes from microorganisms.

    PubMed

    Yamaguchi, Shotaro

    2017-01-01

    Satoshi Ōmura, Professor Emeritus at Kitasato University, was awarded the Nobel Prize for his discovery of a substance of tremendous value to mankind from a microorganism. As a researcher who regularly deals with enzymes produced by microorganisms and a person engaged in microorganism-based business, Professor Ōmura's Nobel Prize fills me with great pride and joy. It is perhaps not surprising that this Nobel Prize-winning research would emerge from Asia, specifically Japan, where people live in harmony with nature rather than try to conquer it. At Amano Enzyme Inc., we devote ourselves to searching for novel enzymes from microorganisms. While incorporating my own experiences, I will recount the stories of a few discoveries of valuable enzyme-producing microbes in soil and bacterial strain libraries. I will also briefly introduce microbial strain library construction as a tool for facilitating the identification of the desired producing bacteria.

  3. PARTICLE-ASSOCIATED MICROORGANISMS IN STORMWATER RUNOFF

    EPA Science Inventory

    This research investigated the effects of blending and chemical addition before analysis of the concentration of microorganisms in stormwater runoff to determine whether clumped or particle-associated organisms play a significant role. All organisms, except for Escherichia coli, ...

  4. Mass Spectrometry for Rapid Characterization of Microorganisms

    NASA Astrophysics Data System (ADS)

    Demirev, Plamen A.; Fenselau, Catherine

    2008-07-01

    Advances in instrumentation, proteomics, and bioinformatics have contributed to the successful applications of mass spectrometry (MS) for detection, identification, and classification of microorganisms. These MS applications are based on the detection of organism-specific biomarker molecules, which allow differentiation between organisms to be made. Intact proteins, their proteolytic peptides, and nonribosomal peptides have been successfully utilized as biomarkers. Sequence-specific fragments for biomarkers are generated by tandem MS of intact proteins or proteolytic peptides, obtained after, for instance, microwave-assisted acid hydrolysis. In combination with proteome database searching, individual biomarker proteins are unambiguously identified from their tandem mass spectra, and from there the source microorganism is also identified. Such top-down or bottom-up proteomics approaches permit rapid, sensitive, and confident characterization of individual microorganisms in mixtures and are reviewed here. Examples of MS-based functional assays for detection of targeted microorganisms, e.g., Bacillus anthracis, in environmental or clinically relevant backgrounds are also reviewed.

  5. Functional Properties of Microorganisms in Fermented Foods.

    PubMed

    Tamang, Jyoti P; Shin, Dong-Hwa; Jung, Su-Jin; Chae, Soo-Wan

    2016-01-01

    Fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. Health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. The present paper is aimed to review the information on some functional properties of the microorganisms associated with fermented foods and beverages, and their health-promoting benefits to consumers.

  6. Automated systems for identification of microorganisms.

    PubMed Central

    Stager, C E; Davis, J R

    1992-01-01

    Automated instruments for the identification of microorganisms were introduced into clinical microbiology laboratories in the 1970s. During the past two decades, the capabilities and performance characteristics of automated identification systems have steadily progressed and improved. This article explores the development of the various automated identification systems available in the United States and reviews their performance for identification of microorganisms. Observations regarding deficiencies and suggested improvements for these systems are provided. PMID:1498768

  7. [Phylogenetic diversity and cold-adaptive hydrolytic enzymes of culturable psychrophilic bacteria associated with sea ice from high latitude ocean, Artic].

    PubMed

    Yu, Yong; Li, Hui-Rong; Chen, Bo; Zeng, Yin-Xin; He, Jian-Feng

    2006-04-01

    The phylogenetic diversity of culturable psychrophilic bacteria associated with sea ice from high latitude sea (77 degrees 30'N - 81 degrees 12'N), Canadian Basin and Greenland sea Arctic, was investigated. A total of 37 psychrophilic strains were isolated using three different methods of ( i ) spread plate method: 100 microL of each dilution ice-melt sample was spreaded onto the surface of Marine 2216 agar (DIFCO laboratories, Detroit, MI) and incubated for 2 to 6 weeks at 4 degrees C; ( ii ) bath culture and spread plate method: 1 mL of sample was added to 9mL of NSW (unamended natural seawater, 0.2 microm prefiltered and autoclaved) and incubated for 1 months at - 1 degrees C, then spread plate method was used to isolate bacterial strains from the pre-cultured samples; ( iii ) cold shock, bath culture and spread plate method: samples were exposed to - 20 degrees C for 24h, then bacterial strains isolated by bath culture and spread plate method under aerobic conditions. Nearly half of psychrophilic strains are isolated by using method iii . 16S rDNA nearly full-length sequence analysis reveal that psychrophilic strains fall in two phylogenetic divisions, gamma-proteobacteria (in the genera Colwellia, Marinobacter, Shewanella, Thalassomonas, Glaciecola, Marinomonas and Pseudoalteromonas) and Cytophaga-Flexibacter-Bacteroides (in the genera Flavobacterium and Psychroflexus). Nine of bacterial isolates (BSi20007, BSi20497, BSi20517, BSi20537, BSi20170, BSi20001, BSi20002, BSi20675 and BSi20101) quite likely represent novel species (16S rDNA sequence similarity below 97%). One of strains (BSi20002) from Canadian Basin shows 100% sequence similarity to the Antarctic Weddell sea ice isolate Marinobacter sp. ANT8277, suggesting bacteria may have a bipolar distribution at the species level. AF283859 sequences were submitted to the BLAST search program of the National Center for Biotechnology Information website (NCBI, http://www. ncbi. nlm.nih. gov). Twenty sequences

  8. Crystallization and preliminary X-ray crystallographic studies of a psychrophilic subtilisin-like protease Apa1 from Antarctic Pseudoalteromonas sp. strain AS-11.

    PubMed

    Dong, Danghong; Ihara, Tokuo; Motoshima, Hiroyuki; Watanabe, Keiichi

    2005-03-01

    The psychrophilic alkaline serine protease Apa1 secreted by the Antarctic psychrotroph Pseudoalteromonas sp. strain AS-11 consists of a subtilisin-like region (293 residues) and an additional insert region (148 residues) that does not show a sequence homology to any proteins in the RCSB Protein Data Bank. Apa1 inhibited with phenylmethanesulfonyl fluoride has been crystallized and X-ray diffraction data have been collected to 1.78 A resolution. The crystals belong to space group C2, with unit-cell parameters a = 122.94, b = 138.48, c = 64.77 A, alpha = gamma = 90, beta = 97.5 degrees. A molecular-replacement solution has been found using the structure of the mesophilic counterpart subtilisin DY with 38% sequence identity to the catalytic domain of Apa1 as a search model. This is the first crystallographic study of a cold-adapted subtilisin-like protease.

  9. Characterization and comparative analysis of psychrophilic and mesophilic alpha-amylases from Euplotes species: a contribution to the understanding of enzyme thermal adaptation.

    PubMed

    Yang, Guang; Yang, Guang; Aprile, Lino; Turturo, Vincenzo; Pucciarelli, Sandra; Pucciarelli, Stefania; Miceli, Cristina

    2013-09-06

    The eukaryotic α-amylase isolated from the psychrophilic ciliated protozoon Euplotes focardii (EfAmy) was expressed in Escherichia coli and biochemically characterized. Its enzymatic activity was compared to that of the homologous protein from the mesophilic congeneric species Euplotes crassus (EcAmy). The comparison of the amino acid composition and the surface residue composition of the two enzymes indicated a preference for tiny residues and the avoidance of charged, aromatic and hydrophobic residues in EfAmy. Our comparative homology modeling study reveals a lack of surface salt bridges, a decreased number of the surface charged residues, decreased hydrogen bonds and bound ions, and a reduction of aromatic-sulfur interactions, cationic-π interactions and disulfide interactions in EfAmy. In contrast, sequence alignment and homology modeling showed five unconserved prolines located on the surface loops of EcAmy. By analyzing amylolytic activity towards soluble starch as the substrate, we determined the temperature and pH dependence, thermostability and kinetic parameters of these two enzymes. We demonstrated that EfAmy shows the characteristics of a psychrophilic α-amylase, such as the highest hydrolytic activity at low temperatures and high thermolability. In contrast, the EcAmy showed mesophilic characteristics with the highest activity at moderate temperatures and a more than 2-fold increased half-life at 50°C compared to EfAmy. The kcat and KM values of EfAmy were higher than those of the mesophilic EcAmy at all tested temperatures. Furthermore, both EfAmy and EcAmy showed maximum activities at pH 9 and maintained high activities in the presence of surfactants. These results suggest the potential applications of EfAmy and EcAmy as ingredients in detergents for industrial applications.

  10. Identification of in vivo HSP90-interacting proteins reveals modularity of HSP90 complexes is dependent on the environment in psychrophilic bacteria

    PubMed Central

    García-Descalzo, Laura; Alcazar, Alberto; Baquero, Fernando

    2010-01-01

    Heat shock protein 90 (HSP90) is a conserved molecular chaperone that functions as part of complexes in which different client proteins target it to diverse sets of substrates. In this paper, HSP90 complexes were investigated in γ-proteobacteria from mild (Shewanella oneidensis) and cold environments (Shewanella frigidimarina and Psychrobacter frigidicola), to determine changes in HSP90 interactions with client proteins in response to the adaptation to cold environments. HSP90 participation in cold adaptation was determined using the specific inhibitor 17-allylamino-geldanamycin. Then, HSP90 was immunoprecipitated from bacterial cultures, and the proteins in HSP90 complexes were analyzed by two-dimensional gel electrophoresis and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. According to HSP90-associated protein analysis, only 15 common proteins were found in both species from the same genus, S. oneidensis and S. frigidimarina, whereas a significant higher number of common proteins were found in both psychrophilic species S. frigidimarina and P. frigidicola 21 (p < 0.001). Only two HSP90-interacting proteins, the chaperone proteins DnaK and GroEL, were common to the three species. Interestingly, some proteins related to energy metabolism (isocitrate lyase, succinyl-CoA synthetase, alcohol dehydrogenase, NAD(+) synthase, and malate dehydrogenase) and some translation factors only interacted with HSP90 in psychrophilic bacteria. We can conclude that HSP90 and HSP90-associated proteins might take part in the mechanism of adaptation to cold environments, and interestingly, organisms living in similar environments conserve similar potential HSP90 interactors in opposition to phylogenetically closely related organisms of the same genus but from different environments. PMID:20890740

  11. Identification of Microorganisms by High Resolution Tandem Mass Spectrometry with Accurate Statistical Significance

    NASA Astrophysics Data System (ADS)

    Alves, Gelio; Wang, Guanghui; Ogurtsov, Aleksey Y.; Drake, Steven K.; Gucek, Marjan; Suffredini, Anthony F.; Sacks, David B.; Yu, Yi-Kuo

    2016-02-01

    Correct and rapid identification of microorganisms is the key to the success of many important applications in health and safety, including, but not limited to, infection treatment, food safety, and biodefense. With the advance of mass spectrometry (MS) technology, the speed of identification can be greatly improved. However, the increasing number of microbes sequenced is challenging correct microbial identification because of the large number of choices present. To properly disentangle candidate microbes, one needs to go beyond apparent morphology or simple `fingerprinting'; to correctly prioritize the candidate microbes, one needs to have accurate statistical significance in microbial identification. We meet these challenges by using peptidome profiles of microbes to better separate them and by designing an analysis method that yields accurate statistical significance. Here, we present an analysis pipeline that uses tandem MS (MS/MS) spectra for microbial identification or classification. We have demonstrated, using MS/MS data of 81 samples, each composed of a single known microorganism, that the proposed pipeline can correctly identify microorganisms at least at the genus and species levels. We have also shown that the proposed pipeline computes accurate statistical significances, i.e., E-values for identified peptides and unified E-values for identified microorganisms. The proposed analysis pipeline has been implemented in MiCId, a freely available software for Microorganism Classification and Identification. MiCId is available for download at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/downloads.html.

  12. Functional microorganisms for functional food quality.

    PubMed

    Gobbetti, M; Cagno, R Di; De Angelis, M

    2010-09-01

    Functional microorganisms and health benefits represent a binomial with great potential for fermented functional foods. The health benefits of fermented functional foods are expressed either directly through the interactions of ingested live microorganisms with the host (probiotic effect) or indirectly as the result of the ingestion of microbial metabolites synthesized during fermentation (biogenic effect). Since the importance of high viability for probiotic effect, two major options are currently pursued for improving it--to enhance bacterial stress response and to use alternative products for incorporating probiotics (e.g., ice cream, cheeses, cereals, fruit juices, vegetables, and soy beans). Further, it seems that quorum sensing signal molecules released by probiotics may interact with human epithelial cells from intestine thus modulating several physiological functions. Under optimal processing conditions, functional microorganisms contribute to food functionality through their enzyme portfolio and the release of metabolites. Overproduction of free amino acids and vitamins are two classical examples. Besides, bioactive compounds (e.g., peptides, γ-amino butyric acid, and conjugated linoleic acid) may be released during food processing above the physiological threshold and they may exert various in vivo health benefits. Functional microorganisms are even more used in novel strategies for decreasing phenomenon of food intolerance (e.g., gluten intolerance) and allergy. By a critical approach, this review will aim at showing the potential of functional microorganisms for the quality of functional foods.

  13. Antifungal and antibacterial activity of marine microorganisms.

    PubMed

    El Amraoui, B; El Amraoui, M; Cohen, N; Fassouane, A

    2014-03-01

    In order to explore marine microorganisms with pharmaceutical potential, marine bacteria, collected from different coastal areas of the Moroccan Atlantic Ocean, were previously isolated from seawater, sediment, marine invertebrates and seaweeds. The antimicrobial activities of these microorganisms were investigated against the pathogens involved in human pathologies. Whole cultures of 34 marine microorganisms were screened for antimicrobial activities using the method of agar diffusion against three Gram-positive bacteria, two Gram-negative bacteria, and against yeast. The results showed that among the 34 isolates studied, 28 (82%) strains have antimicrobial activity against at least one pathogen studied, 11 (32%) strains have antifungal activity and 24 (76%) strains are active against Gram-positive bacteria, while 21 (62%) strains are active against Gram-negative bacteria. Among isolates having antimicrobial activity, 14 were identified and were assigned to the genera Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Enterococcus, Pantoea and Pseudomonas. Due to a competitive role for space and nutrient, the marine microorganisms can produce antibiotic substance; therefore, these marine microorganisms were expected to be potential resources of natural antibiotic products.

  14. Viability of Selected Microorganisms in Hydrocarbon Fuels.

    PubMed

    Hedrick, H G; Carroll, M T; Owen, H P; Pritchard, D J

    1963-11-01

    A laboratory study of the viability of selected microorganisms in a hydrocarbon fuel medium was carried out on 19 species of microorganisms, representative of the types found as natural contaminants in aircraft fuels. More species remained viable when inoculated in pure cultures than when inoculated in mixed (composite) cultures. Of the 19 species selected, 10 were still viable after 3 months and 5 were viable after 4 months in the pure culture inoculants. In the complete composite culture inoculant, the bacterial species which were viable at the end of 4 months were the same as those found in the pure culture inoculant. No fungi remained viable in the complete composite cultures after a 3-week period. The microorganisms which remain viable in a hydrocarbon fuel medium are considered indicative of a satisfactory inoculum to be used as a test culture in laboratory analysis of mechanical control techniques.

  15. Selective enumeration of probiotic microorganisms in cheese.

    PubMed

    Karimi, Reza; Mortazavian, Amir M; Amiri-Rigi, Atefeh

    2012-02-01

    Cheese is a dairy product which has a good potential for delivery of probiotic microorganisms into the human intestine. To be considered to offer probiotic health benefits, probiotics must remain viable in food products above a threshold level (e.g., 10(6) cfu g(-1)) until the time of consumption. In order to ensure that a minimal number of probiotic bacteria is present in the cheese, reliable methods for enumeration are required. The choice of culture medium for selective enumeration of probiotic strains in combination with starters depends on the product matrix, the target group and the taxonomic diversity of the bacterial background flora in the product. Enumeration protocol should be designed as a function of the target microorganism(s) to be quantified in the cheese. An overview of some series of culture media for selective enumeration of commercial probiotic cultures is presented in this review.

  16. Biosurfactants, bioemulsifiers and exopolysaccharides from marine microorganisms.

    PubMed

    Satpute, Surekha K; Banat, Ibrahim M; Dhakephalkar, Prashant K; Banpurkar, Arun G; Chopade, Balu A

    2010-01-01

    Marine biosphere offers wealthy flora and fauna, which represents a vast natural resource of imperative functional commercial grade products. Among the various bioactive compounds, biosurfactant (BS)/bioemulsifiers (BE) are attracting major interest and attention due to their structural and functional diversity. The versatile properties of surface active molecules find numerous applications in various industries. Marine microorganisms such as Acinetobacter, Arthrobacter, Pseudomonas, Halomonas, Myroides, Corynebacteria, Bacillus, Alteromonas sp. have been studied for production of BS/BE and exopolysaccharides (EPS). Due to the enormity of marine biosphere, most of the marine microbial world remains unexplored. The discovery of potent BS/BE producing marine microorganism would enhance the use of environmental biodegradable surface active molecule and hopefully reduce total dependence or number of new application oriented towards the chemical synthetic surfactant industry. Our present review gives comprehensive information on BS/BE which has been reported to be produced by marine microorganisms and their possible potential future applications.

  17. Microorganism Utilization for Synthetic Milk Production

    NASA Technical Reports Server (NTRS)

    Birmele, Michele; Morford, Megan; Khodadad, Christina; Spencer, Lashelle; Richards, Jeffrey; Strayer, Richard; Caro, Janicce; Hummerick, Mary; Wheeler, Ray

    2014-01-01

    A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms.

  18. Combating Antimicrobial Resistance in Foodborne Microorganisms.

    PubMed

    Lai, Edward P C; Iqbal, Zafar; Avis, Tyler J

    2016-02-01

    This review addresses an important public health hazard affecting food safety. Antimicrobial agents are used in foods to reduce or eliminate microorganisms that cause disease. Many traditional organic compounds, novel synthetic organic agents, natural products, peptides, and proteins have been extensively studied for their effectiveness as antimicrobial agents against foodborne Campylobacter spp., Escherichia coli, Listeria spp. and Salmonella. However, antimicrobial resistance can develop in microorganisms, enhancing their ability to withstand the inhibiting or killing action of antimicrobial agents. Knowledge gaps still exist with regard to the actual chemical and microbiological mechanisms that must be identified to facilitate the search for new antimicrobial agents. Technical implementation of antimicrobial active packing films and coatings against target microorganisms must also be improved for extended product shelf life. Recent advances in antimicrobial susceptibility testing can provide researchers with new momentum to pursue their quest for a resistance panacea.

  19. Metabolic activity of microorganisms in evaporites

    NASA Technical Reports Server (NTRS)

    Rothschild, L. J.; Giver, L. J.; White, M. R.; Mancinelli, R. L.

    1994-01-01

    Crystalline salt is generally considered so hostile to most forms of life that it has been used for centuries as a preservative. Here, we present evidence that prokaryotes inhabiting a natural evaporite crust of halite and gypsum are metabolically active while inside the evaporite for at least 10 months. In situ measurements demonstrated that some of these "endoevaporitic" microorganisms (probably the cyanobacterium Synechococcus Nageli) fixed carbon and nitrogen. Denitrification was not observed. Our results quantified the slow microbial activity that can occur in salt crystals. Implications of this study include the possibility that microorganisms found in ancient evaporite deposits may have been part of an evaporite community.

  20. Metabolic activity of microorganisms in evaporites.

    PubMed

    Rothschild, L J; Giver, L J; White, M R; Mancinelli, R L

    1994-06-01

    Crystalline salt is generally considered so hostile to most forms of life that it has been used for centuries as a preservative. Here, we present evidence that prokaryotes inhabiting a natural evaporite crust of halite and gypsum are metabolically active while inside the evaporite for at least 10 months. In situ measurements demonstrated that some of these "endoevaporitic" microorganisms (probably the cyanobacterium Synechococcus Nageli) fixed carbon and nitrogen. Denitrification was not observed. Our results quantified the slow microbial activity that can occur in salt crystals. Implications of this study include the possibility that microorganisms found in ancient evaporite deposits may have been part of an evaporite community.

  1. Functional Properties of Microorganisms in Fermented Foods

    PubMed Central

    Tamang, Jyoti P.; Shin, Dong-Hwa; Jung, Su-Jin; Chae, Soo-Wan

    2016-01-01

    Fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. Health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. The present paper is aimed to review the information on some functional properties of the microorganisms associated with fermented foods and beverages, and their health-promoting benefits to consumers. PMID:27199913

  2. Physiologically anaerobic microorganisms of the deep subsurface

    SciTech Connect

    Stevens, S.E. Jr.; Chung, K.T.

    1991-06-01

    This study seeks to determine numbers, diversity, and morphology of anaerobic microorganisms in 15 samples of subsurface material from the Idaho National Engineering Laboratory, in 18 samples from the Hanford Reservation and in 1 rock sample from the Nevada Test Site; set up long term experiments on the chemical activities of anaerobic microorganisms based on these same samples; work to improve methods for the micro-scale determination of in situ anaerobic microbial activity;and to begin to isolate anaerobes from these samples into axenic culture with identification of the axenic isolates.

  3. Microorganisms in the aetiology of atherosclerosis

    PubMed Central

    Morre, S; Stooker, W; Lagrand, W; van den Brule, A J C; Niessen, H

    2000-01-01

    Recent publications have suggested that infective pathogens might play an important role in the pathogenesis of atherosclerosis. This review focuses on these microorganisms in the process of atherosclerosis. The results of in vitro studies, animal studies, tissue studies, and serological studies will be summarised, followed by an overall conclusion concerning the strength of the association of the microorganism with the pathogenesis of atherosclerosis. The role of the bacteria Chlamydia pneumoniae and Helicobacter pylori, and the viruses human immunodeficiency virus, coxsackie B virus, cytomegalovirus, Epstein-Barr virus, herpes simplex virus, and measles virus will be discussed. Key Words: atherosclerosis • Chlamydia pneumoniae • Helicobacter pylori PMID:11041053

  4. Radiation sensitivity of hyperthermal composting microorganisms

    NASA Astrophysics Data System (ADS)

    Choi, Jong-Il; Yoon, Min-Chul; Kim, Jae-Hun; Yamashita, Masamichi; Kim, Geun Joong; Lee, Ju-Woon

    In the space station and vehicles designed for long human mission, high-temperature compost is a promising technology for decomposing organic waste and producing the fertilizers. In space, the microorganisms could have the changed biological activities or even be mutated by ionizing irradiation. Therefore, in this study, the effect of gamma irradiation on the sensitivity of bacteria in hyperthermal composting was investigated. The sequence analysis of the amplified 16s rDNA genes and amoA gene were used for the identification of composting microorganisms. Viability of microorganisms in compost soil after gamma irradiation was directly visualized with LIVE/DEAD Baclight viability kit. The dominant bacterial genera are Weissella cibaria and Leuconostoc sp. and fungus genera are Metschnikowia bicuspidate and Pichia guilliermondii, respectively. By the gamma irradiation up to the dose of 1 kGy, the microbial population was not changed. Also, the enzyme activities of amylase and cellulose were sustained by the gamma irradiation. These results show that these hyperthermia microorganisms might have the high resistance to gamma radiation and could be used for agriculture in the Space Station.

  5. Microorganism lipid droplets and biofuel development.

    PubMed

    Liu, Yingmei; Zhang, Congyan; Shen, Xipeng; Zhang, Xuelin; Cichello, Simon; Guan, Hongbin; Liu, Pingsheng

    2013-12-01

    Lipid droplet (LD) is a cellular organelle that stores neutral lipids as a source of energy and carbon. However, recent research has emerged that the organelle is involved in lipid synthesis, transportation, and metabolism, as well as mediating cellular protein storage and degradation. With the exception of multi-cellular organisms, some unicellular microorganisms have been observed to contain LDs. The organelle has been isolated and characterized from numerous organisms. Triacylglycerol (TAG) accumulation in LDs can be in excess of 50% of the dry weight in some microorganisms, and a maximum of 87% in some instances. These microorganisms include eukaryotes such as yeast and green algae as well as prokaryotes such as bacteria. Some organisms obtain carbon from CO2 via photosynthesis, while the majority utilizes carbon from various types of biomass. Therefore, high TAG content generated by utilizing waste or cheap biomass, coupled with an efficient conversion rate, present these organisms as bio-tech 'factories' to produce biodiesel. This review summarizes LD research in these organisms and provides useful information for further LD biological research and microorganism biodiesel development.

  6. The genomics of probiotic intestinal microorganisms

    PubMed Central

    Salminen, Seppo; Nurmi, Jussi; Gueimonde, Miguel

    2005-01-01

    An intestinal population of beneficial commensal microorganisms helps maintain human health, and some of these bacteria have been found to significantly reduce the risk of gut-associated disease and to alleviate disease symptoms. The genomic characterization of probiotic bacteria and other commensal intestinal bacteria that is now under way will help to deepen our understanding of their beneficial effects. PMID:15998456

  7. Measuring micro-organism gas production

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Pearson, A. O.; Mills, S. M.

    1973-01-01

    Transducer, which senses pressure buildup, is easy to assemble and use, and rate of gas produced can be measured automatically and accurately. Method can be used in research, in clinical laboratories, and for environmental pollution studies because of its ability to detect and quantify rapidly the number of gas-producing microorganisms in water, beverages, and clinical samples.

  8. Metagenomics: Application of Genomics to Uncultured Microorganisms

    PubMed Central

    Handelsman, Jo

    2004-01-01

    Metagenomics (also referred to as environmental and community genomics) is the genomic analysis of microorganisms by direct extraction and cloning of DNA from an assemblage of microorganisms. The development of metagenomics stemmed from the ineluctable evidence that as-yet-uncultured microorganisms represent the vast majority of organisms in most environments on earth. This evidence was derived from analyses of 16S rRNA gene sequences amplified directly from the environment, an approach that avoided the bias imposed by culturing and led to the discovery of vast new lineages of microbial life. Although the portrait of the microbial world was revolutionized by analysis of 16S rRNA genes, such studies yielded only a phylogenetic description of community membership, providing little insight into the genetics, physiology, and biochemistry of the members. Metagenomics provides a second tier of technical innovation that facilitates study of the physiology and ecology of environmental microorganisms. Novel genes and gene products discovered through metagenomics include the first bacteriorhodopsin of bacterial origin; novel small molecules with antimicrobial activity; and new members of families of known proteins, such as an Na+(Li+)/H+ antiporter, RecA, DNA polymerase, and antibiotic resistance determinants. Reassembly of multiple genomes has provided insight into energy and nutrient cycling within the community, genome structure, gene function, population genetics and microheterogeneity, and lateral gene transfer among members of an uncultured community. The application of metagenomic sequence information will facilitate the design of better culturing strategies to link genomic analysis with pure culture studies. PMID:15590779

  9. Polar Marine Microorganisms and Climate Change.

    PubMed

    Verde, C; Giordano, D; Bellas, C M; di Prisco, G; Anesio, A M

    2016-01-01

    The large diversity of marine microorganisms harboured by oceans plays an important role in planet sustainability by driving globally important biogeochemical cycles; all primary and most secondary production in the oceans is performed by microorganisms. The largest part of the planet is covered by cold environments; consequently, cold-adapted microorganisms have crucial functional roles in globally important environmental processes and biogeochemical cycles cold-adapted extremophiles are a remarkable model to shed light on the molecular basis of survival at low temperature. The indigenous populations of Antarctic and Arctic microorganisms are endowed with genetic and physiological traits that allow them to live and effectively compete at the temperatures prevailing in polar regions. Some genes, e.g. glycosyltransferases and glycosylsynthetases involved in the architecture of the cell wall, may have been acquired/retained during evolution of polar strains or lost in tropical strains. This present work focusses on temperature and its role in shaping microbial adaptations; however, in assessing the impacts of climate changes on microbial diversity and biogeochemical cycles in polar oceans, it should not be forgotten that physiological studies need to include the interaction of temperature with other abiotic and biotic factors.

  10. Engineered microorganisms having resistance to ionic liquids

    SciTech Connect

    Ruegg, Thomas Lawrence; Thelen, Michael P.

    2016-03-22

    The present invention provides for a method of genetically modifying microorganisms to enhance resistance to ionic liquids, host cells genetically modified in accordance with the methods, and methods of using the host cells in a reaction comprising biomass that has been pretreated with ionic liquids.

  11. Biodegradation of Guanidinium By Aquatic Microorganisms.

    DTIC Science & Technology

    1985-12-01

    almost 300 ( malathion ) times higher than the upper value of the estimate.2 1 ,2 5 From the estimated yields and kinetic data for Hansen Creek...6 Most Probable Number Estimations ......................................... 8 Kinetics of...16 4. Kinetic Parameters for Hansen Creek Enrichment Microorganisms ........... 18 5. Most Probable Numbers (MPN) of Guanidinium Degrading

  12. Metabolism of Peptides by Rumen Microorganisms

    PubMed Central

    Wright, D. E.

    1967-01-01

    Rumen microorganisms utilize tryptic peptides from Chlorella protein, forming carbon dioxide, volatile fatty acids, and bacterial protein. Peptide carbon is more efficiently converted into bacterial protein than is amino acid carbon. A progressive degradation of the peptides was demonstrated by use of columns of Sephadex G-25. PMID:6035045

  13. The future of starch bioengineering: GM microorganisms or GM plants?

    PubMed

    Hebelstrup, Kim H; Sagnelli, Domenico; Blennow, Andreas

    2015-01-01

    Plant starches regularly require extensive modification to permit subsequent applications. Such processing is usually done by the use of chemical and/or physical treatments. The use of recombinant enzymes produced by large-scale fermentation of GM microorganisms is increasingly used in starch processing and modification, sometimes as an alternative to chemical or physical treatments. However, as a means to impart the modifications as early as possible in the starch production chain, similar recombinant enzymes may also be expressed in planta in the developing starch storage organ such as in roots, tubers and cereal grains to provide a GM crop as an alternative to the use of enzymes from GM microorganisms. We here discuss these techniques in relation to important structural features and modifications of starches such as: starch phosphorylation, starch hydrolysis, chain transfer/branching and novel concepts of hybrid starch-based polysaccharides. In planta starch bioengineering is generally challenged by yield penalties and inefficient production of the desired product. However, in some situations, GM crops for starch bioengineering without deleterious effects have been achieved.

  14. Opportunities for renewable bioenergy using microorganisms.

    PubMed

    Rittmann, Bruce E

    2008-06-01

    Global warming can be slowed, and perhaps reversed, only when society replaces fossil fuels with renewable, carbon-neutral alternatives. The best option is bioenergy: the sun's energy is captured in biomass and converted to energy forms useful to modern society. To make a dent in global warming, bioenergy must be generated at a very high rate, since the world today uses approximately 10 TW of fossil-fuel energy. And, it must do so without inflicting serious damage on the environment or disrupting our food supply. While most bioenergy options fail on both counts, several microorganism-based options have the potential to produce large amounts of renewable energy without disruptions. In one approach, microbial communities convert the energy value of various biomass residuals to socially useful energy. Biomass residuals come from agricultural, animal, and a variety of industrial operations, as well as from human wastes. Microorganisms can convert almost all of the energy in these wastes to methane, hydrogen, and electricity. In a second approach, photosynthetic microorganisms convert sunlight into biodiesel. Certain algae (eukaryotes) or cyanobacteria (prokaryotes) have high lipid contents. Under proper conditions, these photosynthetic microorganisms can produce lipids for biodiesel with yields per unit area 100 times or more than possible with any plant system. In addition, the non-lipid biomass can be converted to methane, hydrogen, or electricity. Photosynthetic microorganisms do not require arable land, an advantage because our arable land must be used to produce food. Algae or cyanobacteria may be the best option to produce bioenergy at rates high enough to replace a substantial fraction of our society's use of fossil fuels.

  15. Recent trends in ionic liquid (IL) tolerant enzymes and microorganisms for biomass conversion.

    PubMed

    Portillo, Maria Del Carmen; Saadeddin, Anas

    2015-01-01

    Second generation biofuel production depends on lignocellulosic (LC) biomass transformation into simple sugars and their subsequent fermentation into alcohols. However, the main obstacle in this process is the efficient breakdown of the recalcitrant cellulose to sugar monomers. Hence, efficient feedstock pretreatment and hydrolysis are necessary to produce a cost effective biofuel. Recently, ionic liquids (ILs) have been recognized as a promising solvent able to dissolve different biomass feedstocks, providing higher sugar yields. However, most of the hydrolytic enzymes and microorganisms are inactivated, completely or partially, in the presence of even low concentrations of IL, making necessary the discovery of novel hydrolytic enzymes and fermentative microorganisms that are tolerant to ILs. In this review, the current state and the challenges of using ILs as a pretreatment of LC biomass was evaluated, underlining the advances in the discovery and identification of new IL-tolerant enzymes and microorganisms that could improve the bioprocessing of biomass to fuels and chemicals.

  16. Experimental study on biological mixing by micro-organism

    NASA Astrophysics Data System (ADS)

    Kim, Jihoon; Jang, Yonghee; Byun, Doyoung; Nam, Sungwon; Park, Sungsu; Kim, Minjun

    2010-11-01

    Recently, the most challenge in a microfluidic device remains in acting on the device without external source such as syringe pump, magnetic driven force, and electrohydrodynamic force. Instead of the artificial external force, biological propelled mechanism has been paid much attention. Most of micro-organisms have shown to generate straight motion, vibration, and rolling motion. Those motions can be applied to numerous part of micro-actuator or biological robot. In this paper, we investigated the flow field induced by swimming Tetrahymena and suggest this for mixing mechanism. Using micro-particle image velocimetry system, we visualized dynamic motions by DC, AC, and AC+DC galvanotaxis. Due to the periodic signal of AC voltage, Tetrahymena swimming is easily controlled on any desired direction. AC galvanotaxis also allows it to stop at a position only by changing the applied frequency and voltage. Therefore, this galvanotactic motion control can be applied to biological micro-mixer in the microfluidic device.

  17. Sea Ice Microorganisms: Environmental Constraints and Extracellular Responses

    PubMed Central

    Ewert, Marcela; Deming, Jody W.

    2013-01-01

    Inherent to sea ice, like other high latitude environments, is the strong seasonality driven by changes in insolation throughout the year. Sea-ice organisms are exposed to shifting, sometimes limiting, conditions of temperature and salinity. An array of adaptations to survive these and other challenges has been acquired by those organisms that inhabit the ice. One key adaptive response is the production of extracellular polymeric substances (EPS), which play multiple roles in the entrapment, retention and survival of microorganisms in sea ice. In this concept paper we consider two main areas of sea-ice microbiology: the physico-chemical properties that define sea ice as a microbial habitat, imparting particular advantages and limits; and extracellular responses elicited in microbial inhabitants as they exploit or survive these conditions. Emphasis is placed on protective strategies used in the face of fluctuating and extreme environmental conditions in sea ice. Gaps in knowledge and testable hypotheses are identified for future research. PMID:24832800

  18. Recombinant microorganisms for increased production of organic acids

    DOEpatents

    Yi, Jian; Kleff, Susanne; Guettler, Michael V

    2013-04-30

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  19. Recombinant microorganisms for increased production of organic acids

    DOEpatents

    Yi, Jian [East Lansing, MI; Kleff, Susanne [East Lansing, MI; Guettler, Michael V [Holt, MI

    2012-02-21

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  20. Presidential Green Chemistry Challenge: 1999 Designing Greener Chemicals Award

    EPA Pesticide Factsheets

    Presidential Green Chemistry Challenge 1999 award winner, Dow AgroSciences, developed spinosad, a highly selective, low-toxicity, nonpersistant insecticide made by a soil microorganism. It controls many chewing insect pests.

  1. Presidential Green Chemistry Challenge: 2003 Greener Reaction Conditions Award

    EPA Pesticide Factsheets

    Presidential Green Chemistry Challenge 2003 award winner, DuPont, developed a genetically engineered microorganism jointly with Genencor International to manufacture 1,3-propanediol, a building block for Sorona polyester.

  2. Presidential Green Chemistry Challenge: 2010 Small Business Award

    EPA Pesticide Factsheets

    Presidential Green Chemistry Challenge 2010 award winner, LS9, engineered microorganisms to convert fermentable sugars selectively to alkanes, olefins, fatty alcohols, or fatty esters, each in a single-unit biorefinery.

  3. Structural and chemical modification of Fe-rich smectite associated with microbial Fe-respiration by psychrophilic bacteria in King George Island, West Antarctica

    NASA Astrophysics Data System (ADS)

    Jung, J.; Kim, J. Y.; Lim, H. S.; Lee, Y. K.; Kim, O. S.; Park, K.; Lee, J.; Yoon, H.; Kim, J. W.

    2015-12-01

    Biotic/abiotic redox reaction is a ubiquitous process in a mineral alteration and an elemental cycling in the sediments/ocean. The role of psychrophiles in clay mineral alteration was tested in the soil for the seven sites from the coast to the inland at Barton Peninsula. Batch experiments of microbe-mineral interaction under the various temperatures (4 ℃, 15 ℃) that mimics the Antarctic condition were performed to understand the mechanism of biogeochemical alteration of clay minerals. After 12 months incubation of the bulk surface soil samples in the M1 minimal medium, the extent of Fe reduction was reached up to 49 and 42 % at 4 ℃ and 15 ℃. The increase in CEC corresponds to the extent of Fe reduction. Moreover, precipitations of secondary phase mineral such as vivianite were observed only in 12 months enrichment samples at 4 ℃ and 15 ℃. Sulfate reducing bacteria and Fe-reducing bacteria capable of reducing Fe were identified by 16S rRNA pyrosequencing. The Fe reduction coupled to oxidation of organic matter might be enhanced by cooperation of a consortium of Sulfate reducing bacteria and Fe-reducing bacteria. Moreover, Nitrate reducing bacteria which have an ability to oxidize ferrous iron anaerobically with nitrate reduction were identified at 15 ℃. The lower values observed in the extent of Fe reduction at 15 ℃ may be associated with Fe-oxidation induced by nitrate reduction.In order to verify the mechanism of microbial Fe reduction in clay minerals at low temperatures (4 and 15 ℃), Fe-rich Nontronite (NAu-1) and Psychrophilic bacteria were incubated for 4 months in anaerobic condition. Total structural Fe in NAu-1 is 16.4 % and 99.6 % of the total Fe is ferric. The extent of Fe reduction in nontronite was reached up to 11.5 % and 11 % at 4 ℃ and 15 ℃, respectively. The structural modification of biologically Fe-reduced nontronite was observed in the (001) peak shift to the lower 2 theta indicating the layer collapse associated with K

  4. Host-microorganism interactions in lung diseases.

    PubMed

    Marsland, Benjamin J; Gollwitzer, Eva S

    2014-12-01

    Until recently, the airways were thought to be sterile unless infected; however, a shift towards molecular methods for the quantification and sequencing of bacterial DNA has revealed that the airways harbour a unique steady-state microbiota. This paradigm shift is changing the way that respiratory research is approached, with a clear need now to consider the effects of host-microorganism interactions in both healthy and diseased lungs. We propose that akin to recent discoveries in intestinal research, dysbiosis of the airway microbiota could underlie susceptibility to, and progression and chronicity of lung disease. In this Opinion article, we summarize current knowledge of the airway microbiota and outline how host-microorganism interactions in the lungs and other tissues might influence respiratory health and disease.

  5. Characterization of Microorganisms by MALDI Mass Spectrometry

    SciTech Connect

    Petersen, Catherine E.; Valentine, Nancy B.; Wahl, Karen L.

    2008-10-02

    Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for characterization and analysis of microorganisms, specifically bacteria, is described here as a rapid screening tool. The objective of this technique is not comprehensive protein analysis of a microorganism but rather a rapid screening of the organism and the accessible protein pattern for characterization and distinction. This method is based on the ionization of the readily accessible and easily ionizable portion of the protein profile of an organism that is often characteristic of different bacterial species. The utility of this screening approach is yet to reach its full potential but could be applied to food safety, disease outbreak monitoring in hospitals, culture stock integrity and verification, microbial forensics or homeland security applications.

  6. Local climatic adaptation in a widespread microorganism.

    PubMed

    Leducq, Jean-Baptiste; Charron, Guillaume; Samani, Pedram; Dubé, Alexandre K; Sylvester, Kayla; James, Brielle; Almeida, Pedro; Sampaio, José Paulo; Hittinger, Chris Todd; Bell, Graham; Landry, Christian R

    2014-02-22

    Exploring the ability of organisms to locally adapt is critical for determining the outcome of rapid climate changes, yet few studies have addressed this question in microorganisms. We investigated the role of a heterogeneous climate on adaptation of North American populations of the wild yeast Saccharomyces paradoxus. We found abundant among-strain variation for fitness components across a range of temperatures, but this variation was only partially explained by climatic variation in the distribution area. Most of fitness variation was explained by the divergence of genetically distinct groups, distributed along a north-south cline, suggesting that these groups have adapted to distinct climatic conditions. Within-group fitness components were correlated with climatic conditions, illustrating that even ubiquitous microorganisms locally adapt and harbour standing genetic variation for climate-related traits. Our results suggest that global climatic changes could lead to adaptation to new conditions within groups, or changes in their geographical distributions.

  7. [Mixotrophy in microorganisms: ecological and cytophysiological aspects].

    PubMed

    Matantseva, O V; Skarlato, S O

    2013-01-01

    Mixotrophy is the ability to combine autotrophic and heterotrophic modes of nutrition. It is widely spread in various microorganisms, particularly in such important plankton groups as dinoflagellates and cyanobacteria. Mixotrophy has a significant impact on our comprehension of the matter and energy flows in marine ecosystems, and therefore, it is an object of much attention for several recent decades. Nevertheless, the precise data on the balance of auto- and heterotrophy during the mixotrophic growth have been absent so far, which is due, first of all, to insufficient understanding of physiological and molecular ground of this phenomenon. In this review we discuss some ecological and cytophysiological aspects of investigation of mixotrophy in microorganisms as well as possible reasons for relatively slow progress in this area.

  8. UV inactivation of pathogenic and indicator microorganisms

    SciTech Connect

    Chang, J.C.; Ossoff, S.F.; Lobe, D.C.; Dorfman, M.H.; Dumais, C.M.; Qualls, R.G.; Johnson, J.D.

    1985-06-01

    Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.

  9. Microorganisms detection on substrates using QCL spectroscopy

    NASA Astrophysics Data System (ADS)

    Padilla-Jiménez, Amira C.; Ortiz-Rivera, William; Castro-Suarez, John R.; Ríos-Velázquez, Carlos; Vázquez-Ayala, Iris; Hernández-Rivera, Samuel P.

    2013-05-01

    Recent investigations have focused on the improvement of rapid and accurate methods to develop spectroscopic markers of compounds constituting microorganisms that are considered biological threats. Quantum cascade lasers (QCL) systems have revolutionized many areas of research and development in defense and security applications, including his area of research. Infrared spectroscopy detection based on QCL was employed to acquire mid infrared (MIR) spectral signatures of Bacillus thuringiensis (Bt), Escherichia coli (Ec) and Staphylococcus epidermidis (Se), which were used as biological agent simulants of biothreats. The experiments were carried out in reflection mode on various substrates such as cardboard, glass, travel baggage, wood and stainless steel. Chemometrics statistical routines such as principal component analysis (PCA) regression and partial least squares-discriminant analysis (PLS-DA) were applied to the recorded MIR spectra. The results show that the infrared vibrational techniques investigated are useful for classification/detection of the target microorganisms on the types of substrates studied.

  10. Desferrioxamine as immunomodulatory agent during microorganism infection.

    PubMed

    Williams, A; Meyer, D

    2009-01-01

    Southern Africa is burdened with Human Immunodeficiency Virus (HIV) and Mycobacterium tuberculosis (M.tuberculosis) infections as well as conditions of iron (Fe) overload. Highly Active Antiretroviral Therapy (HAART) is used to treat HIV-infection, many drugs exist for the treatment of tuberculosis (new solutions are also being sought because of the existence of multi drug resistant strains of M.tuberculosis) and Fe chelators are commonly used to treat Fe overload. Chelators have also been shown to inhibit the multiplication of numerous microorganisms and hence there are publications suggesting a role for chelators like desferrioxamine (DFO) in the dual treatment of microorganism infection and excess iron. Excess iron fuels pathogen survival which in turn lowers host cell functionality (manifested as altered proliferation, cytokine secretion, etc); withholding iron (via a chelator) reverses the process, even more so when the cells are chelated for longer periods of time. Chelation with DFO is reviewed here by commenting on its immunomodulatory effect.

  11. [Advances in gene engineering of microorganisms].

    PubMed

    Debabov, V G

    1987-10-01

    A novel branch of national economy--biotechnology is being developed, based on genetic engineering. The construction of strains using the methods of molecular cloning has led to-date to creation of new biotechnological processes. Further advance in biotechnology would be mainly promoted by the possibilities of application of gene engineering to reorganization of industrially important microorganisms. These are bacilli employed for production of vitamins, enzymes, insecticides; streptomycetes--the producers of antibiotics; yeasts applied in bakery industry, in production of fodder proteins; pseudomonads which will be helpful in development of effective biological means for protection of environment, etc. So, vector molecules based on plasmids and phages have been constructed for best-studied representatives of industrial microorganisms, the methods of introduction into the cell of hybrid DNA molecules worked out, the problems of optimization of foreign gene expression being currently solved.

  12. Solubilization of Australian lignites by microorganisms

    SciTech Connect

    Catcheside, D.E.A.; Mallett, K.J.; Cox, R.E.

    1988-01-01

    Australia has substantial lignite deposits, particularly in the Latrobe Valley in Victoria where 4.10/sup 10/ tons are accessible with available technologies. The authors have investigated the susceptibility of these coal to solubilization by microorganisms, including species additional to those already identified as active on North American lignites. The data presented here show that acid oxidized lignites from the Latrobe Valley are solubilized by each of seven species of microorganisms previously found to be active on Leonardite and oxidized North American lignites. These are the wood rot fungi: Trametes versicolor, Poria placenta and Phanerochaete chrysosporium, the lignin degrading prokaryote Streptomyces viridosporus and three fungi isolated from lignite in Mississippi: Candida ML-13, Cunninghamelia YML-1 and Penicillium waksmanii.

  13. Assessment of microorganisms from Indonesian Oil Fields

    SciTech Connect

    Kadarwati, S.; Udiharto, M.; Rahman, M.; Jasjfi, E.; Legowo, E.H.

    1995-12-31

    Petroleum resources have been the mainstay of the national development in Indonesia. However, resources are being depleted after over a century of exploitation, while the demand continues to grow with the rapid economic development of the country. In facing the problem, EOR has been applied in Indonesia, such as the steamflooding project in Duri field, but a more energy efficient technology would be preferable. Therefore, MEOR has been recommended as a promising solution. Our study, aimed at finding indigenous microorganisms which can be developed for application in MEOR, has isolated microbes from some oil fields of Indonesia. These microorganisms have been identified, their activities studied, and the effects of their metabolisms examined. This paper describes the research carried out by LEMIGAS in this respect, giving details on the methods of sampling, incubation, identification, and activation of the microbes as well as tests on the effects of their metabolites, with particular attention to those with potential for application in MEOR.

  14. MICROORGANISMS DIE-OFF RATES IN URBAN STORMWATER RUNOFF 2007

    EPA Science Inventory

    Stormwater best management practices (BMPs) are often considered effective tools to mitigate the effects of stormwater pollutants before they are discharged to receiving waters. However, BMP performance for microorganisms removal is not well documented. Microorganisms die-off in...

  15. MICROORGANISMS DIE-OFF RATES IN URBAN STORMWATER RUNOFF 2007

    EPA Science Inventory

    Stormwater best management practices (BMPs) are often considered effective tools to mitigate the effects of stormwater pollutants before they are discharged to receiving waters. However, BMP performance for microorganisms removal is not well documented. Microorganisms die-off in ...

  16. Investigation to identify paint coatings resistive to microorganism growth

    NASA Technical Reports Server (NTRS)

    Cooper, C. W.; Kemp, H. T.

    1971-01-01

    All selected coatings contain nutrients that support microbial growth and survival. Incorporation of microbiocidal agents into coatings more susceptible to attack is recommended for improved inhibition of microorganism growth and for increased protection against deterioration of coatings by microorganisms.

  17. MODELING THE FATE OF MICROORGANISMS IN WATER, WASTEWATER, AND SOIL

    EPA Science Inventory

    The natural environment is filled with microorganisms, most of which are natural residents and colonize various ecological niches. These microorganisms either live independently within the environment, or live in association with various host organisms. There also are places and ...

  18. Microorganism Utilization for Synthetic Milk Production

    NASA Technical Reports Server (NTRS)

    Morford, Megan A.; Khodadad, Christina Louise; Spencer, LaShelle E.; Richards, Jeffrey T.; Strayer, Richard F.; Caro, Janicce; Hummerick, Mary; Birmele, Michele N.; Wheeler, Raymond M.

    2014-01-01

    A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products.

  19. Ecological role of energy taxis in microorganisms.

    PubMed

    Alexandre, Gladys; Greer-Phillips, Suzanne; Zhulin, Igor B

    2004-02-01

    Motile microorganisms rapidly respond to changes in various physico-chemical gradients by directing their motility to more favorable surroundings. Energy generation is one of the most important parameters for the survival of microorganisms in their environment. Therefore it is not surprising that microorganisms are able to monitor changes in the cellular energy generating processes. The signal for this behavioral response, which is called energy taxis, originates within the electron transport system. By coupling energy metabolism and behavior, energy taxis is fine-tuned to the environment a cell finds itself in and allows efficient adaptation to changing conditions that affect cellular energy levels. Thus, energy taxis provides cells with a versatile sensory system that enables them to navigate to niches where energy generation is optimized. This behavior is likely to govern vertical species stratification and the active migration of motile cells in response to shifting gradients of electron donors and/or acceptors which are observed within microbial mats, sediments and soil pores. Energy taxis has been characterized in several species and might be widespread in the microbial world. Genome sequencing revealed that many microorganisms from aquatic and soil environments possess large numbers of chemoreceptors and are likely to be capable of energy taxis. In contrast, species that have a fewer number of chemoreceptors are often found in specific, confined environments, where relatively constant environmental conditions are expected. Future studies focusing on characterizing behavioral responses in species that are adapted to diverse environmental conditions should unravel the molecular mechanisms underlying sensory behavior in general and energy taxis in particular. Such knowledge is critical to a better understanding of the ecological role of energy taxis.

  20. Consolidated bioprocessing method using thermophilic microorganisms

    SciTech Connect

    Mielenz, Jonathan Richard

    2016-02-02

    The present invention is directed to a method of converting biomass to biofuel, and particularly to a consolidated bioprocessing method using a co-culture of thermophilic and extremely thermophilic microorganisms which collectively can ferment the hexose and pentose sugars produced by degradation of cellulose and hemicelluloses at high substrate conversion rates. A culture medium therefor is also provided as well as use of the methods to produce and recover cellulosic ethanol.

  1. Mass Spectrometer for Airborne Micro-Organisms

    NASA Technical Reports Server (NTRS)

    Sinha, M. P.; Friedlander, S. K.

    1986-01-01

    Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

  2. Control of microorganisms in flowing nutrient solutions

    NASA Astrophysics Data System (ADS)

    Evans, R. D.

    1994-11-01

    Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone. This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment. Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.

  3. Control of microorganisms in flowing nutrient solutions.

    PubMed

    Evans, R D

    1994-11-01

    Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone. This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment. Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.

  4. Protein languages differ depending on microorganism lifestyle.

    PubMed

    Grzymski, Joseph J; Marsh, Adam G

    2014-01-01

    Few quantitative measures of genome architecture or organization exist to support assumptions of differences between microorganisms that are broadly defined as being free-living or pathogenic. General principles about complete proteomes exist for codon usage, amino acid biases and essential or core genes. Genome-wide shifts in amino acid usage between free-living and pathogenic microorganisms result in fundamental differences in the complexity of their respective proteomes that are size and gene content independent. These differences are evident across broad phylogenetic groups-a result of environmental factors and population genetic forces rather than phylogenetic distance. A novel comparative analysis of amino acid usage-utilizing linguistic analyses of word frequency in language and text-identified a global pattern of higher peptide word repetition in 376 free-living versus 421 pathogen genomes across broad ranges of genome size, G+C content and phylogenetic ancestry. This imprint of repetitive word usage indicates free-living microorganisms have a bias for repetitive sequence usage compared to pathogens. These findings quantify fundamental differences in microbial genomes relative to life-history function.

  5. Fibrinogenolytic and fibrinolytic activity in oral microorganisms.

    PubMed Central

    Wikström, M B; Dahlén, G; Linde, A

    1983-01-01

    Samples were taken from blood accumulated in dental alveoli after surgical removal of mandibular third molars, from subgingival plaque of teeth with advanced periodontal destructions, from teeth with infected necrotic pulps, and from subjects suffering from angular cheilitis. Of the microorganisms subcultured from these samples, 116 strains were assayed for enzymes degrading fibrinogen and fibrin. Enzymes degrading fibrinogen were assayed with the thin-layer enzyme assay cultivation technique. This assay involves the cultivation of microorganisms on culture agars applied over fibrinogen-coated polystyrene surfaces. Enzymes degrading fibrin were assayed with both a plate assay and a tube assay, in which fibrin was mixed with a microbial culture medium. Microorganisms degrading fibrinogen or fibrin or both were isolated from all sampling sites. Activity was mainly detected in strains of Actinomyces, Bacteroides, Fusobacterium, Peptococcus, Propionibacterium, and Staphylococcus aureus. Most Fusobacterium strains degraded fibrinogen only. Enzymes degrading fibrinogen as well as enzymes degrading fibrin via activation of plasminogen were revealed in strains of Clostridium, S. aureus, and Streptococcus pyogenes. It was generally found that fibrinogen was degraded by more strains than was fibrin, which indicates that different proteases may be involved. PMID:6345573

  6. Stress-tolerant P-solubilizing microorganisms.

    PubMed

    Vassilev, N; Eichler-Löbermann, B; Vassileva, M

    2012-08-01

    Drought, high/low temperature, and salinity are abiotic stress factors accepted as the main reason for crop yield losses in a world with growing population and food price increases. Additional problems create nutrient limitations and particularly low P soil status. The problem of phosphate fertilizers, P plant nutrition, and existing phosphate bearing resources can also be related to the scarcity of rock phosphate. The modern agricultural systems are highly dependent on the existing fertilizer industry based exclusively of this natural, finite, non-renewable resource. Biotechnology offers a number of sustainable solutions that can mitigate these problems by using plant beneficial, including P-solubilizing, microorganisms. This short review paper summarizes the current and future trends in isolation, development, and application of P-solubilizing microorganisms in stress environmental conditions bearing also in mind the imbalanced cycling and unsustainable management of P. Special attention is devoted to the efforts on development of biotechnological strategies for formulation of P-solubilizing microorganisms in order to increase their protection against adverse abiotic factors.

  7. Prokaryotic silicon utilizing microorganisms in the biosphere

    NASA Astrophysics Data System (ADS)

    Gupta, D.; Das, S.

    2012-12-01

    Although a little study has been done to determine the silicon utilizing prokaryotes, our previous experiments indicated that almost all Gram-positive bacteria are silicon utilizing; one of them, Streptococci survived exposure on the lunar surface for a long period in experiment done by others. Our initial experiments with these Gram positive microorganisms showed that there were limited growths of these microorganisms on carbon free silicate medium probably with the help of some carry over carbon and nitrogen during cultivation procedures. However, increase in growth rate after repeated subcultures could not be explained at present. The main groups of prokaryotes which were found silicon utilizing microorganisms were Mycobacterium, Bacillus, Nocardia, Streptomyces, Staphylococcus, Streptococcus, Lactobacillus, and Clostridium. In a another previous study by us when silicon level was studied in such grown up cells on carbon "free" silicate medium by electron prove microanalyser, it was found that silicon in cells grown on carbon "free" silicate medium was much higher (24.9%) than those grown on conventional carbon based medium (0.84%). However, these initial findings are encouraging for our future application of this group of organisms on extraterrestrial surfaces for artificial micro-ecosystem formation. It was found that when electropositive elements are less in extraterrestrial situation, then polymerization of silicon-oxygen profusion may occur easily, particularly in carbon and nitrogen paucity in the rocky worlds of the Universe.

  8. Protein Languages Differ Depending on Microorganism Lifestyle

    PubMed Central

    Grzymski, Joseph J.; Marsh, Adam G.

    2014-01-01

    Few quantitative measures of genome architecture or organization exist to support assumptions of differences between microorganisms that are broadly defined as being free-living or pathogenic. General principles about complete proteomes exist for codon usage, amino acid biases and essential or core genes. Genome-wide shifts in amino acid usage between free-living and pathogenic microorganisms result in fundamental differences in the complexity of their respective proteomes that are size and gene content independent. These differences are evident across broad phylogenetic groups–a result of environmental factors and population genetic forces rather than phylogenetic distance. A novel comparative analysis of amino acid usage–utilizing linguistic analyses of word frequency in language and text–identified a global pattern of higher peptide word repetition in 376 free-living versus 421 pathogen genomes across broad ranges of genome size, G+C content and phylogenetic ancestry. This imprint of repetitive word usage indicates free-living microorganisms have a bias for repetitive sequence usage compared to pathogens. These findings quantify fundamental differences in microbial genomes relative to life-history function. PMID:24828817

  9. Food fermentations: microorganisms with technological beneficial use.

    PubMed

    Bourdichon, François; Casaregola, Serge; Farrokh, Choreh; Frisvad, Jens C; Gerds, Monica L; Hammes, Walter P; Harnett, James; Huys, Geert; Laulund, Svend; Ouwehand, Arthur; Powell, Ian B; Prajapati, Jashbhai B; Seto, Yasuyuki; Ter Schure, Eelko; Van Boven, Aart; Vankerckhoven, Vanessa; Zgoda, Annabelle; Tuijtelaars, Sandra; Hansen, Egon Bech

    2012-03-15

    Microbial food cultures have directly or indirectly come under various regulatory frameworks in the course of the last decades. Several of those regulatory frameworks put emphasis on "the history of use", "traditional food", or "general recognition of safety". Authoritative lists of microorganisms with a documented use in food have therefore come into high demand. One such list was published in 2002 as a result of a joint project between the International Dairy Federation (IDF) and the European Food and Feed Cultures Association (EFFCA). The "2002 IDF inventory" has become a de facto reference for food cultures in practical use. However, as the focus mainly was on commercially available dairy cultures, there was an unmet need for a list with a wider scope. We present an updated inventory of microorganisms used in food fermentations covering a wide range of food matrices (dairy, meat, fish, vegetables, legumes, cereals, beverages, and vinegar). We have also reviewed and updated the taxonomy of the microorganisms used in food fermentations in order to bring the taxonomy in agreement with the current standing in nomenclature.

  10. Biomining: metal recovery from ores with microorganisms.

    PubMed

    Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

    2014-01-01

    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms.

  11. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  12. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  13. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  14. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  15. 40 CFR 725.88 - Uses of a microorganism.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Uses of a microorganism. 725.88... CONTROL ACT REPORTING REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.88 Uses of a microorganism. (a) Assertion of claim. A person who...

  16. Sequence determination and analysis of three plasmids of Pseudomonas sp. GLE121, a psychrophile isolated from surface ice of Ecology Glacier (Antarctica).

    PubMed

    Dziewit, Lukasz; Grzesiak, Jakub; Ciok, Anna; Nieckarz, Marta; Zdanowski, Marek K; Bartosik, Dariusz

    2013-09-01

    Pseudomonas sp. GLE121 (a psychrophilic Antarctic strain) carries three plasmids: pGLE121P1 (6899 bp), pGLE121P2 (8330 bp) and pGLE121P3 (39,583 bp). Plasmids pGLE121P1 and pGLE121P2 show significant sequence similarity to members of the IncP-9 and IncP-7 incompatibility groups, respectively, while the largest replicon, pGLE121P3, is highly related to plasmid pNCPPB880-40 of Pseudomonas syringae pathovar tomato NCPPB880. All three plasmids have a narrow host range, limited to members of the genus Pseudomonas. Plasmid pGLE121P3 encodes a conjugal transfer system, while pGLE121P1 carries only a putative MOB module, conserved in many mobilizable plasmids. Plasmid pGLE121P3 contains an additional load of genetic information, including a pair of genes with homology to the rulAB operon, responsible for ultraviolet radiation (UVR) tolerance. Given the increasing UV exposure in Antarctic regions, the expression of these genes is likely to be an important adaptive response.

  17. Transcriptome-wide analysis of DEAD-box RNA helicase gene family in an Antarctic psychrophilic alga Chlamydomonas sp. ICE-L.

    PubMed

    Liu, Chenlin; Huang, Xiaohang

    2015-09-01

    DEAD-box RNA helicase family proteins have been identified in almost all living organisms. Some of them play a crucial role in adaptation to environmental changes and stress response, especially in the low-temperature acclimation in different kinds of organisms. Compared with the full swing study in plants and bacteria, the characters and functions of DEAD-box family proteins had not been surveyed in algae. To identify genes critical for freezing acclimation in algae, we screened DEAD-box RNA helicase genes from the transcriptome sequences of a psychrophilic microalga Chlamydomonas sp. ICE-L which was isolated from Antarctic sea ice. Totally 39 DEAD-box RNA helicase genes had been identified. Most of the DEAD-box RNA helicase have 1:1 homologous relationships in Chlamydomonas reinhardtii and Chlamydomonas sp. ICE-L with several exceptions. The homologous proteins in ICE-L to the helicases critical for cold or freezing tolerance in Arabidopsis thaliana had been identified based on phylogenetic comparison studies. The response of these helicase genes is not always identical in the Chlamydomonas sp. ICE-L and Arabidopsis under the same low-temperature treatment. The expression of several DEAD-box RNA helicase genes including CiRH5, CiRH25, CiRH28, and CiRH55 were significantly up-regulated under freezing treatment of ICE-L and their function in freezing acclimation of ICE-L deserved further investigation.

  18. Impact of organic loading rate on the performance of psychrophilic dry anaerobic digestion of dairy manure and wheat straw: long-term operation.

    PubMed

    Saady, Noori M Cata; Massé, Daniel I

    2015-04-01

    Development of efficient processes for valorising animal wastes would be a major advancement in cold-climate regions. This paper reports the results of long term (315 days experiment) of novel psychrophilic (20°C) dry anaerobic digestion (PDAD) of cow feces and wheat straw in laboratory scale sequence batch reactor operated at increasing organic loading rate. The PDAD process fed with a mixture of feces and straw (TS of 27%) over a treatment cycle length of 21 days at organic loading rate (OLR) 4.0, 5.0 and 6.0 g TCOD kg(-1) inoculum d(-1) (of 2.9 ± 0.1, 3.7 ± 0.1, and 4.4 ± 0.1g VS kg(-1) inoculum d(-1), respectively) resulted in average specific methane yield (SMY) of 187.3 ± 18.1, 163.6 ± 39.5, 150.8 ± 32.9 N L CH4 kg(-1)VS fed, respectively. PDAD of cow feces and wheat straw is possible with VS-based inoculum-to-substrate ratio of 1.4 at OLR of 6.0 g TCOD kg(-1) inoculum d(-1). Hydrolysis was the limiting step reaction.

  19. Cow, sheep and llama manure at psychrophilic anaerobic co-digestion with low cost tubular digesters in cold climate and high altitude.

    PubMed

    Martí-Herrero, J; Alvarez, R; Cespedes, R; Rojas, M R; Conde, V; Aliaga, L; Balboa, M; Danov, S

    2015-04-01

    The aim of this research is to evaluate the co-digestion of cow and llama manure combined with sheep manure, in psychrophilic conditions and real field low cost tubular digesters adapted to cold climate. Four digesters were monitored in cold climate conditions; one fed with cow manure, a second one with llama manure, the third one with co-digestion of cow-sheep manure and the fourth one was fed with llama-sheep manure. The slurry had a mean temperature of 16.6 °C, the organic load rate was 0.44 kgvs m(-3) d(-1) and the hydraulic retention time was 80 days. After one hundred days biogas production was stable, as was the methane content and the pH of the effluent. The co-digestion of cow-sheep manure results in a biogas production increase of 100% compared to the mono-digestion of cow manure, while co-digestion of llama-sheep manure results in a decrease of 50% in biogas production with respect to mono-digestion of llama manure.

  20. Purification, characterization and preliminary X-ray diffraction analysis of a cold-active lipase (CpsLip) from the psychrophilic bacterium Colwellia psychrerythraea 34H.

    PubMed

    Do, Hackwon; Lee, Jun Hyuck; Kwon, Mi Hyun; Song, Hye Eun; An, Jun Yop; Eom, Soo Hyun; Lee, Sung Gu; Kim, Hak Jun

    2013-08-01

    The putative lipase CpsLip from the psychrophilic bacterium Colwellia psychrerythraea 34H encodes a 34,538 Da, 308-amino-acid protein. In this study, CpsLip (UniProtKB code Q486T5) was expressed as an N-terminal hexahistidine fusion protein in Escherichia coli and purified by affinity and size-exclusion chromatography. The expression and purification of CpsLip enabled characterization of the lipase enzymatic properties of the protein. The optimal activity temperature and pH of the recombinant protein were 298 K and pH 7, respectively. CpsLip maintained over 80% activity in the low-temperature range (278-288 K), thereby suggesting that CpsLip is a cold-active lipase. Substrate-specificity analysis demonstrated that CpsLip exhibits maximum activity towards the C12 acyl group. In addition, sequence-alignment results revealed that CpsLip has a highly conserved catalytic triad in the active site consisting of residues Ser111, Asp135 and His283. Moreover, purified CpsLip was successfully crystallized using the hanging-drop vapour-diffusion method and a complete diffraction data set was collected to 4.0 Å resolution using synchrotron radiation on the BL-5A beamline of the Photon Factory.

  1. Elucidation of stability determinants of cold-adapted monomeric isocitrate dehydrogenase from a psychrophilic bacterium, Colwellia maris, by construction of chimeric enzymes.

    PubMed

    Watanabe, Seiya; Yasutake, Yoshiaki; Tanaka, Isao; Takada, Yasuhiro

    2005-04-01

    To elucidate determinants of differences in thermostability between mesophilic and psychrophilic monomeric isocitrate dehydrogenases (IDHs) from Azotobacter vinelandii (AvIDH) and Colwellia maris (CmIDH), respectively, chimeric enzymes derived from the two IDHs were constructed based on the recently resolved three-dimensional structure of AvIDH, and several characteristics of the two wild-type and six chimeric IDHs were examined. These characteristics were then compared with those of dimeric IDH from Escherichia coli (EcIDH). All recombinant enzymes with a (His)(6)-tag attached to the N-terminal were overexpressed in the E. coli cells and purified by Ni(2+)-affinity chromatography. The catalytic activity (k(cat)) and catalytic efficiency (k(cat)/K(m)) of the wild-type AvIDH and CmIDH were higher than those of EcIDH, implying that an improved catalytic rate more than compensates for the loss of a catalytic site in the former two IDHs due to monomerization. Analyses of the thermostability and kinetic parameters of the chimeric enzymes indicated that region 2, corresponding to domain II, and particularly region 3 located in the C-terminal part of domain I, are involved in the thermolability of CmIDH, and that the corresponding two regions of AvIDH are important for exhibiting higher catalytic activity and affinity for isocitrate than CmIDH. The relationships between the stability, catalytic activity and structural characteristics of AvIDH and CmIDH are discussed.

  2. Sequence and structural investigation of a novel psychrophilic α-amylase from Glaciozyma antarctica PI12 for cold-adaptation analysis.

    PubMed

    Ramli, Aizi Nor Mazila; Azhar, Mohd Akmal; Shamsir, Mohd Shahir; Rabu, Amir; Murad, Abdul Munir Abdul; Mahadi, Nor Muhammad; Illias, Rosli Md

    2013-08-01

    A novel α-amylase was isolated successfully from Glaciozyma antarctica PI12 using DNA walking and reverse transcription-polymerase chain reaction (RT-PCR) methods. The structure of this psychrophilic α-amylase (AmyPI12) from G. antarctica PI12 has yet to be studied in detail. A 3D model of AmyPI12 was built using a homology modelling approach to search for a suitable template and to generate an optimum target-template alignment, followed by model building using MODELLER9.9. Analysis of the AmyPI12 model revealed the presence of binding sites for a conserved calcium ion (CaI), non-conserved calcium ions (CaII and CaIII) and a sodium ion (Na). Compared with its template-the thermostable α-amylase from Bacillus stearothermophilus (BSTA)-the binding of CaII, CaIII and Na ions in AmyPI12 was observed to be looser, which suggests that the low stability of AmyPI12 allows the protein to work at different temperature scales. The AmyPI12 amino acid sequence and model were compared with thermophilic α-amylases from Bacillus species that provided the highest structural similarities with AmyPI12. These comparative studies will enable identification of possible determinants of cold adaptation.

  3. Anaerobic submerged membrane bioreactor (AnSMBR) for municipal wastewater treatment under mesophilic and psychrophilic temperature conditions.

    PubMed

    Martinez-Sosa, David; Helmreich, Brigitte; Netter, Thomas; Paris, Stefania; Bischof, Franz; Horn, Harald

    2011-11-01

    A pilot scale anaerobic submerged membrane bioreactor (AnSMBR) with an external filtration unit for municipal wastewater treatment was operated for 100 days. Besides gas sparging, additional shear was created by circulating sludge to control membrane fouling. During the first 69 days, the reactor was operated under mesophilic temperature conditions. Afterwards, the temperature was gradually reduced to 20 °C. A slow and linear increase in the filtration resistance was observed under critical flux conditions (7 L/(m2 h)) at 35 °C. However, an increase in the fouling rate probably linked to an accumulation of solids, a higher viscosity and soluble COD concentrations in the reactor was observed at 20 °C. The COD removal efficiency was close to 90% under both temperature ranges. Effluent COD and BOD5 concentrations were lower than 80 and 25 mg/L, respectively. Pathogen indicator microorganisms (fecal coliforms bacteria) were reduced by log(10)5. Hence, the effluent could be used for irrigation purposes in agriculture.

  4. Extracellular electron transfer mechanisms between microorganisms and minerals

    SciTech Connect

    Shi, Liang; Dong, Hailiang; Reguera, Gemma; Beyenal, Haluk; Lu, Anhuai; Liu, Juan; Yu, Han-Qing; Fredrickson, James K.

    2016-08-30

    Electrons can be transferred from microorganisms to multivalent metal ions that are associated with minerals and vice versa. As the microbial cell envelope is neither physically permeable to minerals nor electrically conductive, microorganisms have evolved strategies to exchange electrons with extracellular minerals. In this Review, we discuss the molecular mechanisms that underlie the ability of microorganisms to exchange electrons, such as c-type cytochromes and microbial nanowires, with extracellular minerals and with microorganisms of the same or different species. Microorganisms that have extracellular electron transfer capability can be used for biotechnological applications, including bioremediation, biomining and the production of biofuels and nanomaterials.

  5. Nature's Helpers: Using Microorganisms to Remove Trichloroethene (TCE) from Groundwater

    NASA Astrophysics Data System (ADS)

    Delgado, A. G.; Krajmlanik-Brown, R.; Fajardo-Williams, D.; Halloum, I.

    2015-12-01

    Organic chlorinated solvents, such as perchloroethene (PCE) and trichloroethene (TCE), are toxic pollutants threatening ground water quality worldwide and present at many superfund sites. Bioremediation using microorganisms is a promising, green, efficient, and sustainable approach to remove PCE and TCE contamination from soil and groundwater. Under anaerobic conditions, specialized microorganisms (dechlorinators) can reduce these chlorinated ethenes to ethene, an innocuous product, and gain energy for growth by a process known as reductive dechlorination. Dechlorinators are most often present in the environment and in dechlorinating cultures alongside other microbes such as fermenters, methanogens, and acetogens. Fermenters, methanogens, and acetogens syntrophically provide essential nutrients and growth factors to dechlorinators, most specifically to the only members able to reduce TCE all the way to ethene: Dehalococcoides; unfortunately, they also compete with dechlorinators for electron donors. My laboratory devises reductive chlorination platforms to study competition and syntrophy among Dehalococcoides, and other microbes to optimize remediation reactions and transport in the subsurface. We look at competing processes present as part of the natural soil chemistry and microbiology and address these challenges through a combination of enrichment techniques, molecular microbial ecology (deep sequencing), water chemistry, and electron balances. We have applied knowledge gathered in my laboratory to: 1) enrich microbial dechlorinating cultures capable of some of the fastest rates of TCE to ethene dechlorination ever reported, and 2) successfully design and operate three different continuous dechlorinating reactor types. We attribute our successful reactor operations to our multidisciplinary approach which links microbiology and engineering. Our reactors produce robust dechlorinating cultures used for in-situ bioaugmentation of PCE and TCE at contaminated sites

  6. SLIMM: species level identification of microorganisms from metagenomes

    PubMed Central

    Renard, Bernhard Y.; Wieler, Lothar H.; Semmler, Torsten; Reinert, Knut

    2017-01-01

    Identification and quantification of microorganisms is a significant step in studying the alpha and beta diversities within and between microbial communities respectively. Both identification and quantification of a given microbial community can be carried out using whole genome shotgun sequences with less bias than when using 16S-rDNA sequences. However, shared regions of DNA among reference genomes and taxonomic units pose a significant challenge in assigning reads correctly to their true origins. The existing microbial community profiling tools commonly deal with this problem by either preparing signature-based unique references or assigning an ambiguous read to its least common ancestor in a taxonomic tree. The former method is limited to making use of the reads which can be mapped to the curated regions, while the latter suffer from the lack of uniquely mapped reads at lower (more specific) taxonomic ranks. Moreover, even if the tools exhibited good performance in calling the organisms present in a sample, there is still room for improvement in determining the correct relative abundance of the organisms. We present a new method Species Level Identification of Microorganisms from Metagenomes (SLIMM) which addresses the above issues by using coverage information of reference genomes to remove unlikely genomes from the analysis and subsequently gain more uniquely mapped reads to assign at lower ranks of a taxonomic tree. SLIMM is based on a few, seemingly easy steps which when combined create a tool that outperforms state-of-the-art tools in run-time and memory usage while being on par or better in computing quantitative and qualitative information at species-level. PMID:28367376

  7. Quartz crystal microbalance biosensor for rapid detection of aerosolized microorganisms

    NASA Astrophysics Data System (ADS)

    Farka, Zdenĕk.; Kovár, David; Skládal, Petr

    2015-05-01

    Biological warfare agents (BWAs) represent the current menace of the asymmetric war. The early detection of BWAs, especially in the form of bioaerosol, is a challenging task for governments all around the world. Label-free quartz crystal microbalance (QCM) immunosensor and electrochemical immunosensor were developed and tested for rapid detection of BWA surrogate (E. coli) in the form of bioaerosol. Two immobilization strategies for the attachment of antibody were tested; the gold sensor surface was activated by cysteamine and then antibody was covalently linked either using glutaraldehyde, or the reduced antibodies were attached via Sulfo-SMCC. A portable bioaerosol chamber was constructed and used for safe manipulation with aerosolized microorganisms. The dissemination was done using a piezoelectric humidifier, distribution of bioaerosol inside the chamber was ensured using three 12-cm fans. The whole system was controlled remotely using LAN network. The disseminated microbial cells were collected and preconcentrated using the wetted-wall cyclone SASS 2300, the analysis was done using the on-line linked immunosensors. The QCM immunosensor had limit of detection 1×104 CFU·L-1 of air with analysis time 16 min, the whole experiment including dissemination and sensor surface regeneration took 40 min. In case of blank (disseminated sterile buffer), no signal change was observed. The electrochemical immunosensor was able to detect 150 CFU·L-1 of air in 20 min; also in this case, no interferences were observed. Reference measurements were done using particle counter Met One 3400 and by cultivation method on agar plates. The sensors have proved to be applicable for rapid screening of microorganisms in air.

  8. Complete nitrification by a single microorganism

    PubMed Central

    van Kessel, Maartje A.H.J.; Speth, Daan R.; Albertsen, Mads; Nielsen, Per H.; Op den Camp, Huub J.M.; Kartal, Boran; Jetten, Mike S.M.; Lücker, Sebastian

    2016-01-01

    Summary Nitrification is a two-step process where ammonia is considered to first be oxidized to nitrite by ammonia-oxidizing bacteria (AOB) and/or archaea (AOA), and subsequently to nitrate by nitrite-oxidizing bacteria (NOB). Described by Winogradsky already in 18901, this division of labour between the two functional groups is a generally accepted characteristic of the biogeochemical nitrogen cycle2. Complete oxidation of ammonia to nitrate in one organism (complete ammonia oxidation; comammox) is energetically feasible and it was postulated that this process could occur under conditions selecting for species with lower growth-rates but higher growth-yields than canonical ammonia-oxidizing microorganisms3. Still, organisms catalysing this process have not yet been discovered. Here, we report the enrichment and initial characterization of two Nitrospira species that encode all enzymes necessary for ammonia oxidation via nitrite to nitrate in their genomes, and indeed completely oxidize ammonium to nitrate to conserve energy. Their ammonia monooxygenase (AMO) enzymes are phylogenetically distinct from currently identified AMOs, rendering recent acquisition by horizontal gene transfer from known ammonia-oxidizing microorganisms unlikely. We also found highly similar amoA sequences (encoding the AMO subunit A) in public sequence databases, which were apparently misclassified as methane monooxygenases. This recognition of a novel amoA sequence group will lead to an improved understanding on the environmental abundance and distribution of ammonia-oxidizing microorganisms. Furthermore, the discovery of the long-sought-after comammox process will change our perception of the nitrogen cycle. PMID:26610025

  9. Exposure to airborne microorganisms in furniture factories.

    PubMed

    Krysińska-Traczyk, Ewa; Skórska, Czesława; Cholewa, Grazyna; Sitkowska, Jolanta; Milanowski, Janusz; Dutkiewicz, Jacek

    2002-01-01

    Microbiological air sampling was performed in 2 furniture factories located in eastern Poland. In one factory furniture were made from fibreboards and chipboards while in the other from beech wood. It was found that the concentration of total microorganisms (bacteria + fungi) in the air of the facility using beech wood for furniture production (mean 10.7 x (3) cfu/m(3), range 3.3 27.5 x (3) cfu/m(3)) was significantly higher (p < 0.01) compared to microbial concentration in the facility using fibre- and chipboards (mean 3.6 x (3) cfu/m(3), range 1.9-6.2 x (3) cfu/m(3)). On average, the commonest microorganisms in the air of the furniture factories were corynebacteria (Corynebacterium spp., Arthrobacter spp., Brevibacterium spp.) which formed 18.1-50.0% of the total airborne microflora, and fungi (mostly Aspergillus spp., Penicillium spp., Absidia spp. and yeasts) which formed 6.2-54.4% of the total count. The values of the respirable fraction of airborne microflora in the furniture factories varied within fairly wide limits and were between 15.0-62.4%. Altogether, 28 species or genera of bacteria and 12 species or genera of fungi were identified in the air of examined factories, of which respectively 8 and 7 species or genera were reported as having allergenic and/or immunotoxic properties. In conclusion, the workers of furniture factories are exposed to relatively low concentrations of airborne microorganisms which do not exceed the suggested occupational exposure limits. Nevertheless, the presence of allergenic and/or immunotoxic microbial species in the air of factories poses a potential risk of respiratory disease, in particular in sensitive workers.

  10. Extremophilic microorganisms as candidates for extraterrestrial life

    NASA Astrophysics Data System (ADS)

    Seckbach, Joseph; Oren, Aharon

    2000-12-01

    Microbial life is found all over the globe. Diverse communities are even found in such places in which extreme conditions with respect of temperature, salinity, pH, and pressure prevail. Many of these environments were until recently considered too harsh to harbor microbial life. The micro-organisms adapted to an existence at the edge of life are termed extremophiles. They include members of the Prokaryotes (domains Archaea and Bacteria) and the Eukarya, including algae and protozoa. Extremophilic microbes thrive at low and high temperatures -- from subzero levels to above the boiling point of water, at both sides of the pH scale -- in acidic as well as in alkaline media, in hypersaline environments with salt concentrations of up to saturation, at high pressure, both in the deep sea and in the terrestrial deep subsurface where they are exposed to pressures of hundreds of atmospheres, and in other extreme conditions. In many cases they tolerate combinations of more than one environmental stress factor. Some of the extremophiles may be considered as 'living fossils' since their environment resembles the conditions that may have existed during the time life arose on Earth, more than 3.5 billion years ago. In view of these properties the extremophilic micro-organisms may be considered as model organisms when exploring the possibilities of the existence of extraterrestrial life. For example, the microbes discovered in ice cores recovered from the depth of the Lake Vostok in Antarctica may serve as a model simulating conditions prevailing in the permafrost subsurface of Mars or Jupiter's moon Europa. Microbial life in the Dead Sea or in Great Salt Lake may resemble halophilic life forms that may exist elsewhere in the universe, adapted to life at low water activities. Likewise, hyperthermophilic micro-organisms present on Earth in hot springs, hydrothermal vents and other sites heated by volcanic activity in terrestrial or marine areas, may resemble life forms that may

  11. Screening of biosurfactants from cloud microorganisms

    NASA Astrophysics Data System (ADS)

    Sancelme, Martine; Canet, Isabelle; Traikia, Mounir; Uhliarikova, Yveta; Capek, Peter; Matulova, Maria; Delort, Anne-Marie; Amato, Pierre

    2015-04-01

    The formation of cloud droplets from aerosol particles in the atmosphere is still not well understood and a main source of uncertainties in the climate budget today. One of the principal parameters in these processes is the surface tension of atmospheric particles, which can be strongly affected by trace compounds called surfactants. Within a project devoted to bring information on atmospheric surfactants and their effects on cloud droplet formation, we focused on surfactants produced by microorganisms present in atmospheric waters. From our unique collection of microorganisms, isolated from cloud water collected at the Puy-de-Dôme (France),1 we undertook a screening of this bank for biosurfactant producers. After extraction of the supernatants of the pure cultures, surface tension of crude extracts was determined by the hanging drop technique. Results showed that a wide variety of microorganisms are able to produce biosurfactants, some of them exhibiting strong surfactant properties as the resulting tension surface decreases to values less then 35 mN.m-1. Preliminary analytical characterization of biosurfactants, obtained after isolation from overproducing cultures of Rhodococcus sp. and Pseudomonas sp., allowed us to identify them as belonging to two main classes, namely glycolipids and glycopeptides. 1. Vaïtilingom, M.; Attard, E.; Gaiani, N.; Sancelme, M.; Deguillaume, L.; Flossmann, A. I.; Amato, P.; Delort, A. M. Long-term features of cloud microbiology at the puy de Dôme (France). Atmos. Environ. 2012, 56, 88-100. Acknowledgements: This work is supported by the French-USA ANR SONATA program and the French-Slovakia programs Stefanik and CNRS exchange.

  12. Biofilms: Survival Mechanisms of Clinically Relevant Microorganisms

    PubMed Central

    Donlan, Rodney M.; Costerton, J. William

    2002-01-01

    Though biofilms were first described by Antonie van Leeuwenhoek, the theory describing the biofilm process was not developed until 1978. We now understand that biofilms are universal, occurring in aquatic and industrial water systems as well as a large number of environments and medical devices relevant for public health. Using tools such as the scanning electron microscope and, more recently, the confocal laser scanning microscope, biofilm researchers now understand that biofilms are not unstructured, homogeneous deposits of cells and accumulated slime, but complex communities of surface-associated cells enclosed in a polymer matrix containing open water channels. Further studies have shown that the biofilm phenotype can be described in terms of the genes expressed by biofilm-associated cells. Microorganisms growing in a biofilm are highly resistant to antimicrobial agents by one or more mechanisms. Biofilm-associated microorganisms have been shown to be associated with several human diseases, such as native valve endocarditis and cystic fibrosis, and to colonize a wide variety of medical devices. Though epidemiologic evidence points to biofilms as a source of several infectious diseases, the exact mechanisms by which biofilm-associated microorganisms elicit disease are poorly understood. Detachment of cells or cell aggregates, production of endotoxin, increased resistance to the host immune system, and provision of a niche for the generation of resistant organisms are all biofilm processes which could initiate the disease process. Effective strategies to prevent or control biofilms on medical devices must take into consideration the unique and tenacious nature of biofilms. Current intervention strategies are designed to prevent initial device colonization, minimize microbial cell attachment to the device, penetrate the biofilm matrix and kill the associated cells, or remove the device from the patient. In the future, treatments may be based on inhibition of genes

  13. Microorganisms and biomolecules in space hard environment

    NASA Technical Reports Server (NTRS)

    Horneck, G.

    1981-01-01

    Microorganisms and biomolecules exposed to space vacuum and to different intensities of selected wavelengths of solar ultraviolet radiation is studied. The influence of these factors, applied singly or simultaneously, on the integrity of microbial systems and biomolecules is measured. Specifically, this experiment will study in Bacillus subtilis spores (1) disturbances in subsequent germination, outgrowth, and colony formation; (2) photochemical reactions of the DNA and protein in vivo and in vitro and their role in biological injury; and (3) the efficiency of repair processes in these events.

  14. Temperature response of Antarctic cryptoendolithic photosynthetic microorganisms

    NASA Technical Reports Server (NTRS)

    Ocampo-Friedmann, R.; Meyer, M. A.; Chen, M.; Friedmann, E. I.

    1988-01-01

    Growth responses to temperatures between 12.5 [degrees] C and 25 degrees C were determined for five photosynthetic microorganisms isolated from the Ross Desert cryptoendolithic community. Among eukaryotic algae, two strains of Trebouxia sp. have an upper temperature limit of 20 degrees C, and two strains of Hemichloris antarctica of 25 degrees C. The cyanobacterium Chroococcidiopsis sp., in contrast, grows at temperatures above 25 degrees C. These and earlier studies suggest that the eukaryotic algae of the Antarctic cryptoendolithic community have an upper temperature limit near 25 degrees C.

  15. Resistance of soil microorganisms to starvation.

    NASA Technical Reports Server (NTRS)

    Chen, M.; Alexander, M.

    1972-01-01

    Most groups of soil microorganisms died when exposed to prolonged starvation in a carbon-free solution, but the relative abundance of Bacillus and actinomycetes increased with time. Certain nonspore-forming bacteria also persisted. The ability of individual soil isolates to endure starvation in solution was not correlated with their glycogen content or rate of endogenous respiration. However, cells of the resistant populations were rich in poly-beta-hydroxybutyrate, whereas the starvation-susceptible bacteria generally contained little of this substance. Poly-beta-hydroxybutyrate was used rapidly in cells deprived of exogenous sources of carbon.

  16. Green biosynthesis of floxuridine by immobilized microorganisms.

    PubMed

    Rivero, Cintia W; Britos, Claudia N; Lozano, Mario E; Sinisterra, Jose V; Trelles, Jorge A

    2012-06-01

    This work describes an efficient, simple, and green bioprocess for obtaining 5-halogenated pyrimidine nucleosides from thymidine by transglycosylation using whole cells. Biosynthesis of 5-fluoro-2'-deoxyuridine (floxuridine) was achieved by free and immobilized Aeromonas salmonicida ATCC 27013 with an 80% and 65% conversion occurring in 1 h, respectively. The immobilized biocatalyst was stable for more than 4 months in storage conditions (4 °C) and could be reused at least 30 times without loss of its activity. This microorganism was able to biosynthesize 2.0 mg L(-1) min(-1) (60%) of 5-chloro-2'-deoxyuridine in 3 h. These halogenated pyrimidine 2'-deoxynucleosides are used as antitumoral agents.

  17. Sterilization of Microorganisms by Ozone and Ultrasound

    NASA Astrophysics Data System (ADS)

    Krasnyj, V. V.; Klosovskij, A. V.; Panasko, T. A.; Shvets, O. M.; Semenova, O. T.; Taran, V. S.; Tereshin, V. I.

    2008-03-01

    The results of recent experimental methods of sterilization of microorganisms with the use of ozone and ultrasound are presented. The main aim was to optimize the process of sterilization in water solution taking into account the ozone concentration, the power of ultrasonic emitter and the temperature of water. In the present work, the ultrasonic cavitation with simultaneous ozone generation has been used. The high ozone concentration in water solution was achieved by two-barrier glow discharge generated at atmospheric pressure and a cooling thermo-electric module. Such a sterilizer consists of ozone generator in a shape of flat electrodes covered with dielectric material and a high-voltage pulsed power supply of 250 W. The sterilization camera was equipped with ultrasonic source operated at 100 W. The experiments on the inactivation of bacteria of the Bacillus Cereus type were carried out in the distilled water saturated by ozone. The ozone concentration in the aqueous solution was 10 mg/1, whereas the ozone concentration at the output of ozone generator was 30 mg/1. The complete inactivation of spores took 15 min. Selection of the temperature of water, the ozone concentrations and ultrasonic power allowed to determine the time necessary for destroying the row of microorganisms.

  18. Evolution of microorganism locomotion induced by starvation

    NASA Astrophysics Data System (ADS)

    Sibona, G. J.

    2007-07-01

    The search strategies of many organisms play a fundamental role in their competition to survive in a given environment. In this context, the propulsion systems of microorganisms have evolved during life history, to optimize the suitable use of energy they take from nutrients. Starting from a model for the motion of Brownian objects with internal energy depot, we show that the propulsion system of microorganisms has an optimal regimen while searching for new sources of food. Bacteria with a too low or too high energy expenditure in propulsion, moving in a nutrient-depleted environment, do not reach remote distances. In this sense, the mean square displacement has a maximum for a finite value of the propulsion rate. Species using the most efficient locomotion system have a considerable advantage for survival in hostile environments, a common situation in the ocean. Moreover, we found the existence of a lower size limit for useful locomotion. This suggests that, for organisms whose linear dimensions are below a certain threshold, it is advantageous not to use any propulsion mechanism at all, a result that is in agreement with what is observed in nature.

  19. Nonenzymatic microorganism identification based on ribosomal RNA

    NASA Astrophysics Data System (ADS)

    Ives, Jeffrey T.; Pierini, Alicia M.; Stokes, Jeffrey A.; Wahlund, Thomas M.; Read, Betsy; Bechtel, James H.; Bronk, Burt V.

    1999-11-01

    Effective defense against biological warfare (BW) agents requires rapid, fieldable and accurate systems. For micro- organisms like bacteria and viruses, ribosomal RNA (rRNA) provides a valuable target with multiple advantages of species specificity and intrinsic target amplification. Vegetative and spore forms of bacteria contain approximately 104 copies of rRNA. Direct detection of rRNA copies can eliminate some of the interference and preparation difficulties involved in enzymatic amplification methods. In order to apply the advantages of rRNA to BW defense, we are developing a fieldable system based on 16S rRNA, physical disruption of the micro-organism, solid phase hybridization, and fluorescence detection. Our goals include species-specific identification, complete operation from raw sample to identification in 15 minutes or less, and compact, fieldable instrumentation. Initial work on this project has investigated the lysis and hybridization steps, the species-specificity of oligonucleotides probes, and the development of a novel electromagnetic method to physically disrupt the micro- organisms. Target bacteria have been Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis). Continuing work includes further development of methods to rapidly disrupt the micro-organisms and release the rRNA, improved integration and processing, and extension to bacterial and mammalian viruses like MS2 and vesicular stomatitis virus.

  20. Microorganisms resistant to free-living amoebae.

    PubMed

    Greub, Gilbert; Raoult, Didier

    2004-04-01

    Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human "Troy," and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens.

  1. The cellular slime mold: eukaryotic model microorganism.

    PubMed

    Urushihara, Hideko

    2009-04-01

    Cellular slime molds are eukaryotic microorganisms in the soil. They feed on bacteria as solitary amoebae but conditionally construct multicellular forms in which cell differentiation takes place. Therefore, they are attractive for the study of fundamental biological phenomena such as phagocytosis, cell division, chemotactic movements, intercellular communication, cell differentiation, and morphogenesis. The most widely used species, Dictyostelium discoideum, is highly amenable to experimental manipulation and can be used with most recent molecular biological techniques. Its genome and cDNA analyses have been completed and well-annotated data are publicly available. A larger number of orthologues of human disease-related genes were found in D. discoideum than in yeast. Moreover, some pathogenic bacteria infect Dictyostelium amoebae. Thus, this microorganism can also offer a good experimental system for biomedical research. The resources of cellular slime molds, standard strains, mutants, and genes are maintained and distributed upon request by the core center of the National BioResource Project (NBRP-nenkin) to support Dictyostelium community users as well as new users interested in new platforms for research and/or phylogenic consideration.

  2. Bioremediation of trinitrotolulene by a ruminal microorganism

    SciTech Connect

    Lee, Taejin; Williamson, K.J.; Craig, A.M.

    1995-10-01

    2,4,6-trinitrotoluene (TNT) has been widely used for the production of explosives because of its low boiling point, high stability, low impact sensitivity, and safe manufacture. More than 1,100 military facilities, each potentially contaminated with munitions waste, are expected to require treatment of more than one million cubic yards of contaminated soils. The cost associated with remediation of these sites has been estimated to be in excess of $1.5 billion. Recently, researchers have studied ruminal microorganisms in relation to their ability to degrade xenobiotic compounds. Many of these organisms are strict anaerobes with optimal redox potentials as low as -420 mV. Ruminal organisms have been shown capable of destroying some pesticides, such as parathion, p-nitrophenol, and biphenyl-type compounds; thiono isomers, and nitrogen-containing heterocyclic plant toxins such as the pyrrolizidine alkaloids. Many of these compounds have structures similar to TNT. A TNT-degrading ruminal microorganism has been isolated from goat rumen fluid with successive enrichments on triaminotoluene (TAT) and TNT. The isolate, designated G.8, utilizes nitrate and lactate as the primary energy source. G.8 was able to tolerate and metabolite levels of TNT up to the saturation point of 125 mg/l.

  3. Microorganisms Resistant to Free-Living Amoebae

    PubMed Central

    Greub, Gilbert; Raoult, Didier

    2004-01-01

    Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human “Troy,” and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens. PMID:15084508

  4. Medical Significance of Microorganisms in Spacecraft Environment

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Ott, C. Mark

    2007-01-01

    Microorganisms can spoil food supplies, contaminate drinking water, release noxious volatile compounds, initiate allergic responses, contaminate the environment, and cause infectious diseases. International acceptability limits have been established for bacterial and fungal contaminants in air and on surfaces, and environmental monitoring is conducted to ensure compliance. Allowable levels of microorganism in water and food have also been established. Environmental monitoring of the space shuttle, the Mir, and the ISS have allowed for some general conclusions. Generally, the bacteria found in air and on interior surfaces are largely of human origin such as Staphylococcus spp., Micrococcus spp. Common environmental genera such as Bacillus spp. are the most commonly isolated bacteria from all spacecraft. Yeast species associated with humans such as Candida spp. are commonly found. Aspergillus spp., Penicillium spp., and Cladosporium spp. are the most commonly isolated filamentous fungi. Microbial levels in the environment differ significantly depending upon humidity levels, condensate accumulation, and availability of carbon sources. However, human "normal flora" of bacteria and fungi can result in serious, life-threatening diseases if human immunity is compromised. Disease incidence is expected to increase as mission duration increases.

  5. Large-scale production of diesel-like biofuels - process design as an inherent part of microorganism development.

    PubMed

    Cuellar, Maria C; Heijnen, Joseph J; van der Wielen, Luuk A M

    2013-06-01

    Industrial biotechnology is playing an important role in the transition to a bio-based economy. Currently, however, industrial implementation is still modest, despite the advances made in microorganism development. Given that the fuels and commodity chemicals sectors are characterized by tight economic margins, we propose to address overall process design and efficiency at the start of bioprocess development. While current microorganism development is targeted at product formation and product yield, addressing process design at the start of bioprocess development means that microorganism selection can also be extended to other critical targets for process technology and process scale implementation, such as enhancing cell separation or increasing cell robustness at operating conditions that favor the overall process. In this paper we follow this approach for the microbial production of diesel-like biofuels. We review current microbial routes with both oleaginous and engineered microorganisms. For the routes leading to extracellular production, we identify the process conditions for large scale operation. The process conditions identified are finally translated to microorganism development targets. We show that microorganism development should be directed at anaerobic production, increasing robustness at extreme process conditions and tailoring cell surface properties. All the same time, novel process configurations integrating fermentation and product recovery, cell reuse and low-cost technologies for product separation are mandatory. This review provides a state-of-the-art summary of the latest challenges in large-scale production of diesel-like biofuels.

  6. Psychrophilic (6--15 {degree}C) high-rate anaerobic treatment of malting wastewater in a two-module expanded granular sludge bed system

    SciTech Connect

    Rebac, S.; Lier, J.B. van; Lens, P.; Cappellen, J. van; Vermeulen, M.; Stams, A.J.M.; Lettinga, G.; Dekkers, F.; Swinkels, K.T.M.

    1998-11-01

    Psychrophilic (6--15 C) anaerobic treatment of malting wastewater was investigated. A two-module expanded granular sludge bed reactor system with a total volume of 140 dm{sup 3} was used to treat malting wastewater having a soluble and total chemical oxygen demand (COD) between 233 and 1778 mg dm{sup {minus}3} and between 317 and 4422 mg dm{sup {minus}3}, respectively. The removal efficiencies at 6 C were 47 and 71% of the soluble and volatile fatty acids (VFA) COD, at organic loading rates (OLR) ranging between 3.3 and 5.8 kg of COD m{sup {minus}3} day{sup {minus}1}. The removal efficiencies at 10--15 C were 67--78 and 90--96% of the soluble and VFA COD at an OLR between 2.8 and 12.3 kg of COD m{sup {minus}3} day{sup {minus}1}. The specific methanogenic activity of the sludge present in each module increased 2--3-fold during system operation for 400 days. The relatively high concentration of suspended solids in the influent (25% of the total COD) caused a deterioration of the sludge bed in the first reactor module. This was aggravated by excessive growth of acidifying biomass, which persisted in the first module sludge bed and resulted in granular sludge flotation. However, the second module could accommodate the increased OLR, this providing a very high effluent quality (soluble COD < 200 mg dm{sup {minus}3}) of the total system. The stability of module 1 concerning suspended solids could be restored by presettling the wastewater.

  7. Structural and Chemical Modification of Fe-Rich Smectite Associated with Microbial Fe-Respiration By Psychrophilic Bacteria in King George Island, West Antarctica

    NASA Astrophysics Data System (ADS)

    Jung, J.; Kim, J.; Lim, H. S.; Yoon, H.; Lee, Y. K.; Park, K.; Lee, J.; Kim, J. W.

    2014-12-01

    Surface soil samples were collected from Antarctic exploration (2010/2011, 2011/2012) at Barton Peninsula, King George Island, West Antarctica to determine the feasible biological alteration of clay minerals in Antarctica where the physical weathering is considered to be a major process. Seven areas (1226-1, 1226-2, 0101-4, 0105-1, 0105-2, 0107-2, 0107-3) from the coast toward the inland were investigated. The duration of exposure of soil samples to the air depending on the retraction of ice to the inland may affect the microbial activity resulting in the biogeochemical mineral alteration. The multiline of techniques for example, X-ray diffraction (XRD), Scanning Electron Microscope (SEM), wet chemistry analysis including the extent of Fe(III) reduction, and batch experiments of microbe-mineral interaction under the low temperature that mimics the Antarctic condition to understand the mechanism of biogeochemical alteration of clay minerals. Clay minerals of smectite, mica, chlorite and kaolinite were detected in the XRD profiles. The variation of relative amount of clay minerals in the regions indicated that the physical/biological alteration might be different depending on the duration of ice retraction. From the batch experiment using Nontronite (NAu-1), moreover, we confirm that Psychrophilic bacteria (Shewanella sp. isolated from King George Island) reduce structural Fe(III) of clay mineral, and occur structural change of smectite at low temperature (4℃ and 15℃). The present study, therefore, would present the feasibility of biological effects on chemical modification through the structural changes in clay mineral in cold environment and suggest a new pathway of Fe-supply into the Antarctic Ocean.

  8. Minerals and Microorganisms in Evaporite Environments

    NASA Astrophysics Data System (ADS)

    Morris, P. A.; Brigmon, R. L.

    2010-12-01

    Traditional analysis of evaporite environments have either focused on the geology or the halophilic organisms. It is relatively rare that the two have been combined and even rarer that both disciplines have been incorporated in comparing evaporite sites. The variation in evaporite environments does influence microbial ecology and fossilization processes as each site varies in pH, temperature, presence or absence springs, and spring chemistry. Understanding the evaporite environments is important for planetary scientists as they serve as analogs for evaluating extraterrestrial materials, including the potential for water and ultimately life. For example Mars lander, rover and orbital missions have identified the evaporite signatures of gypsum, carbonates and chlorides, all indicating that water existed at sometime in the planets geological history. Terrestrial evaporite sites all possess halophilic tolerant life. In some instances such as the Dead Sea, Israel, it is restricted to microbial life, but in other sites there are higher life forms. The microbes associated with these evaporite sites can produce biofilms as a method to develop their own microenvironments. Microorganisms can be observed colonizing specific ecological niches or gradients can be created by these environments. These gradients occur due the localized drying and weathering patterns that create different soil chemistry. The microorganisms in turn colonize specific areas more suitable to their specific metabolic needs. For example, under anaerobic conditions with sulfur and methane prevalent methanogenic and/or sulfur reducing microbial species may be observed. However, under similar chemistry environments with the exception of aerobic conditions sulfur oxidizer and/or methanotrophic microorganism may occur. Because of their conspicuous colored pigments purple sulfur bacteria are frequently observed in anoxic zones of lakes, sulfur springs, and stratified evaporite crusts. Some of these bacteria

  9. Genetic engineering of microorganisms for biodiesel production

    PubMed Central

    Lin, Hui; Wang, Qun; Shen, Qi; Zhan, Jumei; Zhao, Yuhua

    2013-01-01

    Biodiesel, as one type of renewable energy, is an ideal substitute for petroleum-based diesel fuel and is usually made from triacylglycerides by transesterification with alcohols. Biodiesel production based on microbial fermentation aiming to establish more efficient, less-cost and sustainable biodiesel production strategies is under current investigation by various start-up biotechnology companies and research centers. Genetic engineering plays a key role in the transformation of microbes into the desired cell factories with high efficiency of biodiesel production. Here, we present an overview of principal microorganisms used in the microbial biodiesel production and recent advances in metabolic engineering for the modification required. Overexpression or deletion of the related enzymes for de novo synthesis of biodiesel is highlighted with relevant examples. PMID:23222170

  10. Feeding, Swimming and Navigation of Colonial Microorganisms

    NASA Astrophysics Data System (ADS)

    Kirkegaard, Julius; Bouillant, Ambre; Marron, Alan; Leptos, Kyriacos; Goldstein, Raymond

    2016-11-01

    Animals are multicellular in nature, but evolved from unicellular organisms. In the closest relatives of animals, the choanoflagellates, the unicellular species Salpincgoeca rosetta has the ability to form colonies, resembling true multicellularity. In this work we use a combination of experiments, theory, and simulations to understand the physical differences that arise from feeding, swimming and navigating as colonies instead of as single cells. We show that the feeding efficiency decreases with colony size for distinct reasons in the small and large Péclet number limits, and we find that swimming as a colony changes the conventional active random walks of microorganism to stochastic helices, but that this does not hinder effective navigation towards chemoattractants.

  11. Early photosynthetic microorganisms and environmental evolution

    NASA Technical Reports Server (NTRS)

    Golubic, S.

    1980-01-01

    Microfossils which are preserved as shrivelled kerogenous residues provide little information about cellular organization and almost none about the metabolic properties of the organisms. The distinction between prokaryotic vs eukaryotic, and phototrophic vs chemo- and organotrophic fossil microorganisms rests entirely on morphological comparisons with recent counterparts. The residual nature of the microbial fossil record promotes the conclusion that it must be biased toward (a) most abundant organisms, (b) those most resistant to degradation, and (c) those inhabiting environments with high preservation potential e.g., stromatolites. These criteria support the cyanophyte identity of most Precambrian microbial fossils on the following grounds: (1) as primary producers they dominate prokaryotic communities in modern extreme environments, e.g., intertidal zone; (2) several morphological counterparts of modern cyanophytes and microbial fossils have been established based on structure, cell division patterns and degradation sequences. The impact of anaerobic and oxygenic microbial photosynthesis on the evolution of Precambrian environments is discussed.

  12. Microorganism billiards in closed plane curves.

    PubMed

    Krieger, Madison S

    2016-12-01

    Recent experiments have shown that many species of microorganisms leave a solid surface at a fixed angle determined by steric interactions and near-field hydrodynamics. This angle is completely independent of the incoming angle. For several collisions in a closed body this determines a unique type of billiard system, an aspecular billiard in which the outgoing angle is fixed for all collisions. We analyze such a system using numerical simulation of this billiard for varying tables and outgoing angles, and also utilize the theory of one-dimensional maps and wavefront dynamics. When applicable we cite results from and compare our system to similar billiard systems in the literature. We focus on examples from three broad classes: the ellipse, the Bunimovich billiards, and the Sinai billiards. The effect of a noisy outgoing angle is also discussed.

  13. Catabolism of dimethylsulphoniopropionate: microorganisms, enzymes and genes.

    PubMed

    Curson, Andrew R J; Todd, Jonathan D; Sullivan, Matthew J; Johnston, Andrew W B

    2011-10-11

    The compatible solute dimethylsulphoniopropionate (DMSP) has important roles in marine environments. It is an anti-stress compound made by many single-celled plankton, some seaweeds and a few land plants that live by the shore. Furthermore, in the oceans it is a major source of carbon and sulphur for marine bacteria that break it down to products such as dimethyl sulphide, which are important in their own right and have wide-ranging effects, from altering animal behaviour to seeding cloud formation. In this Review, we describe how recent genetic and genomic work on the ways in which several different bacteria, and some fungi, catabolize DMSP has provided new and surprising insights into the mechanisms, regulation and possible evolution of DMSP catabolism in microorganisms.

  14. On micro-organisms of the stratosphere.

    PubMed

    Imshenetsky, A A; Lysenko, S V; Kazakov, G A; Ramkova, N V

    1976-01-01

    The lower parts of the biosphere are well studied since various live beings are found in oceans and at the bottom of large hollows. Contrary to this, we have no data about the upper boundaries of the biosphere. Samples were obtained with the help of specially constructed analysers which were installed in meteorological rockets and reached an altitude of 100 km. With the help of methods completely excluding the possibility of contamination of analysers with outside microflora it became possible to prove that earth microbes carried by air currents are present in the stratosphere. At an altitude of 48-77 km Circinella muscae, Asp. niger, Penicillium notatum were found as well as mycobacterium and micrococcus. The correlation of these cultures with external factors is studied and the weight of one conidium or one cell in isolated micro-organisms is estimated. These investigations will continue.

  15. Breakdown of plastics and polymers by microorganisms.

    PubMed

    Kawai, F

    1995-01-01

    The interest in environmental issues is still growing and there are increasing demands to develop materials which do not burden the environment significantly. Awareness of the waste problem and its impact on the environment has awakened new interest in the area of degradable polymers. Biodegradation is necessary for water-soluble or water-miscible polymers because they eventually enter streams which can neither be recycled nor incinerated. It is important to consider the microbial degradation of natural and synthetic polymers in order to understand what is necessary for biodegradation and the mechanisms involved. This requires both biochemical insight and understanding of the interactions between materials and microorganisms. It is now widely requested that polymeric materials come from renewable resources instead of petrochemical sources. The microbial production of polymeric and oligomeric materials is also described.

  16. Laboratory studies of ocean mixing by microorganisms

    NASA Astrophysics Data System (ADS)

    Martinez-Ortiz, Monica; Dabiri, John O.

    2011-11-01

    Ocean mixing plays a major role in nutrient and energy transport and is an important input to climate models. Recent studies suggest that the contribution of fluid transport by swimming microorganisms to ocean mixing may be of the same order of magnitude as winds and tides. An experimental setup has been designed in order to study the mixing efficiency of vertical migration of plankton. To this end, a stratified water column is created to model the ocean's density gradient. The vertical migration of Artemia Salina (brine shrimp) within the water column is controlled via luminescent signals on the top and bottom of the column. By fluorescently labelling portions of the water column, the stirring of the density gradient by the animals is visualized and quantified. Preliminary results show that the vertical movement of these organisms produces enhanced mixing relative to control cases in which only buoyancy forces and diffusion are present.

  17. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    SciTech Connect

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  18. Genetic engineering of microorganisms for biodiesel production.

    PubMed

    Lin, Hui; Wang, Qun; Shen, Qi; Zhan, Jumei; Zhao, Yuhua

    2013-01-01

    Biodiesel, as one type of renewable energy, is an ideal substitute for petroleum-based diesel fuel and is usually made from triacylglycerides by transesterification with alcohols. Biodiesel production based on microbial fermentation aiming to establish more efficient, less-cost and sustainable biodiesel production strategies is under current investigation by various start-up biotechnology companies and research centers. Genetic engineering plays a key role in the transformation of microbes into the desired cell factories with high efficiency of biodiesel production. Here, we present an overview of principal microorganisms used in the microbial biodiesel production and recent advances in metabolic engineering for the modification required. Overexpression or deletion of the related enzymes for de novo synthesis of biodiesel is highlighted with relevant examples.

  19. Micro-organism extraction from biological samples using DEP forces enhanced by osmotic shock.

    PubMed

    Bisceglia, Emilie; Cubizolles, Myriam; Mallard, Frédéric; Vinet, Françoise; Français, Olivier; Le Pioufle, Bruno

    2013-03-07

    On the road towards efficient diagnostics of infectious diseases, sample preparation is considered as the key step and remains a real technical challenge. Finding new methods for extraction of micro-organisms from a complex biological sample remains a major challenge prior to pathogen detection and analysis. This paper reports a new technique for capturing and isolating micro-organisms from a complex sample. To achieve the segregation of pathogens and blood cells, dielectrophoretic forces applied to bioparticles previously subjected to an osmotic shock are successfully implemented within a dedicated microfluidic device. Our device involves an electrode array of interdigitated electrodes, coated with an insulating layer, to minimize electrochemical reactions with the electrolyte and to enable long-time use. The electric field intensity inside the device is optimized, considering the insulating layer, for a given frequency bandwidth, enabling the separation of bioparticles by dielectrophoretic forces. Our predictions are based on analytical models, consistent with numerical simulations (using COMSOL Multiphysics) and correlated to experimental results. The method and device have been shown to extract different types of micro-organisms spiked in a blood cell sample. We strongly believe that this new separation approach may open the way towards a simple device for pathogen extraction from blood and more generally complex samples, with potential advantages of genericness and simplicity.

  20. Practical aspects of sampling for organic dusts and microorganisms.

    PubMed

    Morey, P R

    1990-01-01

    Air sampling for organic dusts and microorganisms was carried out in silos when moldy silage was discarded through the discharge chute. Concentrations of respirable dust and airborne viable microorganisms exceeded 20 mg/m3 and 1 x 10(9)/m3, respectively, when dry silage was removed from silos. Much lower concentrations of dust and microorganisms were present when wet silage was discarded. Impinger and filter cassette samplers were equally effective in collecting the hardy spores present in silage dusts.

  1. The ecology of micro-organisms in a closed environment

    NASA Technical Reports Server (NTRS)

    Fox, L.

    1971-01-01

    Microorganisms under closed environmental ecological conditions with reference to astronauts infectious diseases, discussing bacteria growth in Biosatellite 2 and earth based closed chamber experiments

  2. Engineered microorganisms capable of producing target compounds under anaerobic conditions

    DOEpatents

    Buelter, Thomas [Denver, CO; Meinhold, Peter [Denver, CO; Feldman, Reid M. Renny [San Francisco, CA; Hawkins, Andrew C [Parker, CO; Urano, Jun [Irvine, CA; Bastian, Sabine [Pasadena, CA; Arnold, Frances [La Canada, CA

    2012-01-17

    The present invention is generally provides recombinant microorganisms comprising engineered metabolic pathways capable of producing C3-C5 alcohols under aerobic and anaerobic conditions. The invention further provides ketol-acid reductoisomerase enzymes which have been mutated or modified to increase their NADH-dependent activity or to switch the cofactor preference from NADPH to NADH and are expressed in the modified microorganisms. In addition, the invention provides isobutyraldehyde dehydrogenase enzymes expressed in modified microorganisms. Also provided are methods of producing beneficial metabolites under aerobic and anaerobic conditions by contacting a suitable substrate with the modified microorganisms of the present invention.

  3. Ultrasonic manipulation of locomotive microorganisms and evaluation of their activity

    NASA Astrophysics Data System (ADS)

    Saito, Mitsunori; Kitamura, Norio; Terauchi, Masaki

    2002-12-01

    Acoustic manipulation of locomotive microorganisms, i.e., euglena and paramecia, was conducted by using ultrasonic standing waves of ˜3 MHz. Microorganisms were trapped at the intersections of the nodes in the two orthogonal standing waves and were transferred horizontally and vertically by the suitable ultrasonic frequency change. Aggregation of microorganisms was also observed in the process of the cyclic frequency change. The trapping efficiency depended on both ultrasonic power density and the activity of microorganisms. The effects of water temperature and illumination on their activity were evaluated by measuring the ultrasonic trapping efficiency.

  4. Analysis of Membrane Lipids of Airborne Micro-Organisms

    NASA Technical Reports Server (NTRS)

    MacNaughton, Sarah

    2006-01-01

    A method of characterization of airborne micro-organisms in a given location involves (1) large-volume filtration of air onto glass-fiber filters; (2) accelerated extraction of membrane lipids of the collected micro-organisms by use of pressurized hot liquid; and (3) identification and quantitation of the lipids by use of gas chromatography and mass spectrometry. This method is suitable for use in both outdoor and indoor environments; for example, it can be used to measure airborne microbial contamination in buildings ("sick-building syndrome"). The classical approach to analysis of airborne micro-organisms is based on the growth of cultureable micro-organisms and does not provide an account of viable but noncultureable micro-organisms, which typically amount to more than 90 percent of the micro-organisms present. In contrast, the present method provides an account of all micro-organisms, including cultureable, noncultureable, aerobic, and anaerobic ones. The analysis of lipids according to this method makes it possible to estimate the number of viable airborne micro-organisms present in the sampled air and to obtain a quantitative profile of the general types of micro-organisms present along with some information about their physiological statuses.

  5. Bioremediation of Industrial Waste Through Enzyme Producing Marine Microorganisms.

    PubMed

    Sivaperumal, P; Kamala, K; Rajaram, R

    2017-01-01

    Bioremediation process using microorganisms is a kind of nature-friendly and cost-effective clean green technology. Recently, biodegradation of industrial wastes using enzymes from marine microorganisms has been reported worldwide. The prospectus research activity in remediation area would contribute toward the development of advanced bioprocess technology. To minimize industrial wastes, marine enzymes could constitute a novel alternative in terms of waste treatment. Nowadays, the evidence on the mechanisms of bioremediation-related enzymes from marine microorganisms has been extensively studied. This review also will provide information about enzymes from various marine microorganisms and their complexity in the biodegradation of comprehensive range of industrial wastes.

  6. Marine microorganisms as a promising and sustainable source of bioactive molecules.

    PubMed

    Romano, G; Costantini, M; Sansone, C; Lauritano, C; Ruocco, N; Ianora, A

    2016-05-03

    There is an urgent need to discover new drug entities due to the increased incidence of severe diseases as cancer and neurodegenerative pathologies, and reducing efficacy of existing antibiotics. Recently, there is a renewed interest in exploring the marine habitat for new pharmaceuticals also thanks to the advancement in cultivation technologies and in molecular biology techniques. Microorganisms represent a still poorly explored resource for drug discovery. The possibility of obtaining a continuous source of bioactives from marine microorganisms, more amenable to culturing compared to macro-organisms, may be able to meet the challenging demands of pharmaceutical industries. This would enable a more environmentally-friendly approach to drug discovery and overcome the over-utilization of marine resources and the use of destructive collection practices. The importance of the topic is underlined by the number of EU projects funded aimed at improving the exploitation of marine organisms for drug discovery.

  7. MALDI-TOF MS: an upcoming tool for rapid detection of antibiotic resistance in microorganisms.

    PubMed

    Kostrzewa, Markus; Sparbier, Katrin; Maier, Thomas; Schubert, Sören

    2013-12-01

    MALDI-TOF MS profiling for microorganism detection has already been demonstrated in the 1990s, but has evolved to the first-line identification method in many laboratories just during the past five years. While this application of MALDI-TOF MS has proven its broad applicability, accuracy, robustness, and cost-effectiveness it is of particular interest to expand the capabilities of the mass spectrometric platform. Resistance detection is the most desirable further application of MALDI-TOF MS in microbiology, but maybe also the most challenging. Different approaches have been published regarding diverse antibiotic drugs and distinct microorganism classes. The current review shall give an overview about the developments of the recent years and their potential to get transformed in clinical useful assays in the future.

  8. Isotopes in geobiochemistry: tracing metabolic pathways in microorganisms of environmental relevance with stable isotopes.

    PubMed

    Adrian, Lorenz; Marco-Urrea, Ernest

    2016-10-01

    Stable isotopes are flexibly used as tracers to investigate environmental processes, microorganisms responsible for environmental transformations, syntrophic relationships in consortia, and metabolic pathways. With the advent of widely accessible high-resolution, highly accurate and sensitive mass spectrometers connected to liquid chromatography (LC-MS/MS) and the explosion of microbial genome sequence information the options to apply stable isotope tracers to geobiochemical topics have multiplied. With methods at hand to analyze biochemical pathways and enzymatic functions of yet-uncultivated microorganisms even in mixed cultures, a wide field of new discoveries can be expected. Applications rely both on the high sensitivity to detect trace amounts of biological material in slow or non-growing cultures and on the high multi-dimensional resolution of LC-MS/MS to allow the separation of complex samples and to retrieve phylogenetic information. Challenges and examples of stable isotope applications to describe geobiochemical processes are reviewed. Overall, the potential is not yet sufficiently deployed.

  9. The small domain of cytochrome f from the psychrophile Chlamydomonas raudensis UWO 241 modulates the apparent molecular mass and decreases the accumulation of cytochrome f in the mesophile Chlamydomonas reinhardtii.

    PubMed

    Gudynaite-Savitch, Loreta; Loiselay, Christelle; Savitch, Leonid V; Simmonds, John; Kohalmi, Susanne E; Choquet, Yves; Hüner, Norman P A

    2007-10-01

    Cytochrome f from the psychrophile Chlamydomonas raudensis UWO 241 has a lower thermostability of its c-type heme and an apparent molecular mass that is 7 kDa lower than that of the model mesophilic green alga Chlamydomonas reinhardtii. We combined chloroplast transformation, site-directed mutagensis, and the creation of chimeric fusion constructs to assess the contribution of specific domains and (or) amino acids residues to the structure, stability, and accumulation of cytochrome f, as well as its function in photosynthetic intersystem electron transport. We demonstrate that differences in the amino acid sequence of the small domain and specific charged amino acids in the large domain of cytochrome f alter the physical properties of this protein but do not affect either the thermostability of the c-type heme, the apparent half-life of cytochrome f in the presence of the chloroplastic protein synthesis inhibitor chloramphenicol, or the capacity for photosynthetic intersystem electron transport, measured as e-/P700. However, pulse-labeling with [14C]acetate, combined with immunoblotting, indicated that the negative autoregulation of cytochrome f accumulation observed in mesophilic C. reinhardtii transformed with chimeric constructs from the psychrophile was likely the result of the defective association of the chimeric forms of cytochrome f with the other subunits of the cytochrome b6/f complex native to the C. reinhardtii wild type. These results are discussed in terms of the unique fatty acid composition of the thylakoid membranes of C. raudensis UWO 241 adapted to cold environments.

  10. Nitrogen utilization pathways of soil microorganisms

    NASA Astrophysics Data System (ADS)

    Pinggera, J.; Geisseler, D.; Merbach, I.; Ludwig, B.

    2012-04-01

    Nitrogen (N) is an essential nutrient for all organisms. In terrestrial ecosystems N occurs predominantly in the form of organic matter. Here, soil microorganisms can use two possible mechanisms for the uptake of organic N: the direct route and the mobilization-immobilization-turnover (MIT) route. In the direct route simple organic molecules are taken up directly into the cell. The deamination occurs inside the cell and only the surplus N is released into the soil solution. In the second route, the deamination occurs outside the cell and all N is mineralized before assimilation. To determine the importance of the different N uptake pathways of soil microorganisms an incubation experiment (21 days, 20°C) is currently being carried out. Corn leaves with different C to N ratios (20, 40) and (NH4)2SO4 have been added to three soils (Haplic Chernozem, FAO) with different fertilization histories (300dt/ha farmyard manure every second year, mineral NPK fertilizer, no fertilization) from the long-term experiment at Bad Lauchstädt. Contents of NH4+, NO3- and microbial biomass C (Cmic) and N (Nmic), CO2 production, potential protease activity, gross N mineralization and mineralization of added amino acids will be determined after 3, 7 and 21 days. Preliminary results show that the protease activity (without addition of corn residues) decreased in the order manure-fertilized soil (18.26 mg tyrosine kg-1 soil h-1) > Soil with mineral NPK fertilizer (17.45 mg tyrosine kg-1 soil h-1) > unfertilized soil (11.34 mg tyrosine kg-1 oven dry soil h-1). The turnover of amino acids after 24h was higher for the manure-fertilized soil (99.5% of the added amino acids were consumed) than for the NPK- fertilized and unfertilized soils (76%). The effects of the fertilization histories on the temporal dynamics of the different biological properties (Cmic, Nmic), CO2 production, protease activity and N mineralization rates will be presented.

  11. Featherweight Challenge

    ERIC Educational Resources Information Center

    Love, Tyler S.; Ryan, Larry

    2012-01-01

    As science, technology education, and engineering programs suffer budget cuts, educators continue to seek cost-effective activities that engage students and reinforce standards. The featherweight challenge is a hands-on activity that challenges students to continually refine their design while not breaking the budget. This activity uses one of the…

  12. Microorganisms in Food--Their Significance and Methods of Enumeration.

    ERIC Educational Resources Information Center

    Andrews, S.

    1980-01-01

    Described are laboratory methods for enumerating microorganisms in food. These methods are utilized to determine if foods are potentially hazardous to the consumer due to high concentrations of microorganisms. Discussed are indicator organisms, including coliforms, interococci, yeasts, and molds; food poisoning organisms (staphylococci and…

  13. Climate change effects on beneficial plant-microorganism interactions.

    PubMed

    Compant, Stéphane; van der Heijden, Marcel G A; Sessitsch, Angela

    2010-08-01

    It is well known that beneficial plant-associated microorganisms may stimulate plant growth and enhance resistance to disease and abiotic stresses. The effects of climate change factors such as elevated CO(2), drought and warming on beneficial plant-microorganism interactions are increasingly being explored. This now makes it possible to test whether some general patterns occur and whether different groups of plant-associated microorganisms respond differently or in the same way to climate change. Here, we review the results of 135 studies investigating the effects of climate change factors on beneficial microorganisms and their interaction with host plants. The majority of studies showed that elevated CO(2) had a positive influence on the abundance of arbuscular and ectomycorrhizal fungi, whereas the effects on plant growth-promoting bacteria and endophytic fungi were more variable. In most cases, plant-associated microorganisms had a beneficial effect on plants under elevated CO(2). The effects of increased temperature on beneficial plant-associated microorganisms were more variable, positive and neutral, and negative effects were equally common and varied considerably with the study system and the temperature range investigated. Moreover, numerous studies indicated that plant growth-promoting microorganisms (both bacteria and fungi) positively affected plants subjected to drought stress. Overall, this review shows that plant-associated microorganisms are an important factor influencing the response of plants to climate change.

  14. Genome-based microorganism classification using coalition formulation game.

    PubMed

    Chung, Byung Chang; Han, Gyu-Bum; Cho, Dong-Ho

    2015-01-01

    Genome-based microorganism classification is the one of interesting issues in microorganism taxonomy. However, the advance in sequencing technology requires a low-complex algorithm to process a great amount of bio sequence data. In this paper, we suggest a coalition formation game for microorganism classification, which can be implemented in distributed manner. We extract word frequency feature from microorganism sequences and formulate the coalition game model that considers the distance among word frequency features. Then, we propose a coalition formation algorithm for clustering microorganisms with feature similarity. The performance of proposed algorithm is compared with that of conventional schemes by means of an experiment. According to the result, we showed that the correctness of proposed distributed algorithm is similar to that of conventional centralized schemes.

  15. Dynamic size spectrometry of airborne microorganisms: Laboratory evaluation and calibration

    NASA Astrophysics Data System (ADS)

    Qian, Yinge; Willeke, Klaus; Ulevicius, Vidmantas; Grinshpun, Sergey A.; Donnelly, Jean

    Bioaerosol samplers need to be calibrated for the microorganisms of interest. The Aerosizer, a relatively new aerodynamic size spectrometer, is shown to be a suitable dynamic instrument for the evaluation and calibration of such samplers in the laboratory, prior to their use in the field. It provides the necessary reference count against which the microbiological response of the sampler can be compared. It measures the health-significant aerodynamic diameters of microorganisms down to 0.5 μm, thus including most of the bacteria, fungi and pollen found in outdoor and indoor air environments. Comparison tests with a laser size spectrometer indicate that the suspension of microorganisms needs to be washed several times before aerosolization to avoid coating of the airborne microorganisms with nutrients and microbial slime from the suspension, and to reduce the residue particles to sizes below the lowest size of the aerosolized microorganisms.

  16. Polyhydroxybutyrate: plastic made and degraded by microorganisms.

    PubMed

    Hankermeyer, C R; Tjeerdema, R S

    1999-01-01

    Polyhydroxybutyrate (PHB) offers many advantages over traditional petrochemically derived plastics. In addition to its complete biodegradability, PHB is formed from renewable resources. It possesses better physical properties than polypropylene for food packaging applications and is completely nontoxic. The poor low-impact strength of PHB is solved by incorporation of hydroxyvalerate monomers into the polymer to produce polyhydroxybutyrate-co-valerate (PHBV), which is commercially marketed under the trade name Biopol. Like PHB, PHBV completely degrades into carbon dioxide and water under aerobic conditions. Microbial synthesis of PHB is the best method for industrial production because it ensures the proper stereochemistry for biodegradation. Microorganisms synthesize and store PHB under nutrient-limited conditions and degrade and metabolize it when the limitation is removed. Current production employs Alcaligenes eutrophus because it grows efficiently on glucose as a carbon source, accumulates PHB up to 80% of its dry weight, and is able to synthesize PHBV when propionic acid is added to the feedstock. PHBV is currently 16 times the price of polypropylene. However, the development of transgenic PHA-producing organisms is expected to greatly reduce its cost. Benefits of using transgenic systems include lack of a depolymerase system, ability to use faster-growing organisms, production of highly purified polymers, and ability to utilize inexpensive carbon sources. Because transgenic plants may someday result in the evolution of plastic crops that could lower the price of PHA to a competitive level, future research will surely focus on such recombinant DNA techniques.

  17. Snow as a habitat for microorganisms

    NASA Technical Reports Server (NTRS)

    Hoham, Ronald W.

    1989-01-01

    There are three major habitats involving ice and snow, and the microorganisms studied from these habitats are most eukaryotic. Sea ice is inhabited by algae called diatoms, glacial ice has sparse populations of green algai cal desmids, and the temporary and permanent snows in mountainous regions and high latitudes are inhabited mostly by green algal flagellates. The life cycle of green algal flagellates is summarized by discussing the effects of light, temperature, nutrients, and snow melts. Specific examples of optimal conditions and environmental effects for various snow algae are given. It is not likely that the eukaryotic snow algae presented are candidated for life on the planet Mars. Evolutionally, eukaryotic cells as know on Earth may not have had the opportunity to develop on Mars (if life evolved at all on Mars) since eukaryotes did not appear on Earth until almost two billion years after the first prokaryotic organisms. However, the snow/ice ecosystems on Earth present themselves as extreme habitats were there is evidence of prokaryotic life (eubacteria and cyanbacteria) of which literally nothing is known. Any future surveillances of extant and/or extinct life on Mars should include probes (if not landing sites) to investigate sites of concentrations of ice water. The possibility of signs of life in Martian polar regions should not be overlooked.

  18. Evaluation of actinide biosorption by microorganisms

    SciTech Connect

    Happel, A.M.

    1996-06-01

    Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated ground waters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams may preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by non-living, non-metabolizing microbial biomass thus avoiding the problems associated with living systems. We are investigating biosorption with the long term goal of developing microbial technologies for the remediation of actinides.

  19. Effectiveness of ozone against periodontal pathogenic microorganisms.

    PubMed

    Huth, Karin C; Quirling, Martina; Lenzke, Stefanie; Paschos, Ekaterini; Kamereck, Klaus; Brand, Korbinian; Hickel, Reinhard; Ilie, Nicoleta

    2011-06-01

    Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 μg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.

  20. Heavy metal removal and recovery using microorganisms

    SciTech Connect

    Wilde, E.W. ); Benemann, J.R. , Pinole, CA )

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

  1. Autonomous support for microorganism research in space

    NASA Technical Reports Server (NTRS)

    Fleet, Mary L.; Miller, Mark S.; Shipley, Derek, E.; Smith, Jeff D.

    1992-01-01

    A preliminary design for performing on orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the Commercial Experiment Transporter (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with in-flight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibrations, and radiation are provided for environmental regulation and experimental data collection. Additional experimental data acquisition includes optical density measurement, microscopy, video, and film photography. On-board full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing.

  2. Autonomous support for microorganism research in space

    NASA Technical Reports Server (NTRS)

    Luttges, M. W.; Klaus, D. M.; Fleet, M. L.; Miller, M. S.; Shipley, D. E.; Smith, J. D.

    1992-01-01

    A preliminary design for performing on-orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the COMmercial Experiment Transported (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with inflight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibration, and radiation are provided for environmental regulation and experimental data collection. Additional experiment data acquisition includes optical density measurement, microscopy, video, and file photography. Onboard full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing.

  3. RNA polymerase gene, microorganism having said gene and the production of RNA polymerase by the use of said microorganism

    DOEpatents

    Kotani, Hirokazu; Hiraoka, Nobutsugu; Obayashi, Akira

    1991-01-01

    SP6 bacteriophage RNA polymerase is produced by cultivating a new microorganism (particularly new strains of Escherichia coli) harboring a plasmid that carries SP6 bacteriophage RNA polymerase gene and recovering SP6 bacteriophage RNA polymerase from the culture broth. SP6 bacteriophage RNA polymerase gene is provided as are new microorganisms harboring a plasmid that carries SP6 bacteriophage RNA polymerase gene.

  4. Challenges and opportunities of airborne metagenomics.

    PubMed

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-05-06

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles.

  5. Challenges and Opportunities of Airborne Metagenomics

    PubMed Central

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-01-01

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles. PMID:25953766

  6. From the Lab to the Farm: An Industrial Perspective of Plant Beneficial Microorganisms.

    PubMed

    Parnell, J Jacob; Berka, Randy; Young, Hugh A; Sturino, Joseph M; Kang, Yaowei; Barnhart, D M; DiLeo, Matthew V

    2016-01-01

    Any successful strategy aimed at enhancing crop productivity with microbial products ultimately relies on the ability to scale at regional to global levels. Microorganisms that show promise in the lab may lack key characteristics for widespread adoption in sustainable and productive agricultural systems. This paper provides an overview of critical considerations involved with taking a strain from discovery to the farmer's field. In addition, we review some of the most effective microbial products on the market today, explore the reasons for their success and outline some of the major challenges involved in industrial production and commercialization of beneficial strains for widespread agricultural application. General processes associated with commercializing viable microbial products are discussed in two broad categories, biofertility inoculants and biocontrol products. Specifically, we address what farmers desire in potential microbial products, how mode of action informs decisions on product applications, the influence of variation in laboratory and field study data, challenges with scaling for mass production, and the importance of consistent efficacy, product stability and quality. In order to make a significant impact on global sustainable agriculture, the implementation of plant beneficial microorganisms will require a more seamless transition between laboratory and farm application. Early attention to the challenges presented here will improve the likelihood of developing effective microbial products to improve crop yields, decrease disease severity, and help to feed an increasingly hungry planet.

  7. From the Lab to the Farm: An Industrial Perspective of Plant Beneficial Microorganisms

    PubMed Central

    Parnell, J. Jacob; Berka, Randy; Young, Hugh A.; Sturino, Joseph M.; Kang, Yaowei; Barnhart, D. M.; DiLeo, Matthew V.

    2016-01-01

    Any successful strategy aimed at enhancing crop productivity with microbial products ultimately relies on the ability to scale at regional to global levels. Microorganisms that show promise in the lab may lack key characteristics for widespread adoption in sustainable and productive agricultural systems. This paper provides an overview of critical considerations involved with taking a strain from discovery to the farmer’s field. In addition, we review some of the most effective microbial products on the market today, explore the reasons for their success and outline some of the major challenges involved in industrial production and commercialization of beneficial strains for widespread agricultural application. General processes associated with commercializing viable microbial products are discussed in two broad categories, biofertility inoculants and biocontrol products. Specifically, we address what farmers desire in potential microbial products, how mode of action informs decisions on product applications, the influence of variation in laboratory and field study data, challenges with scaling for mass production, and the importance of consistent efficacy, product stability and quality. In order to make a significant impact on global sustainable agriculture, the implementation of plant beneficial microorganisms will require a more seamless transition between laboratory and farm application. Early attention to the challenges presented here will improve the likelihood of developing effective microbial products to improve crop yields, decrease disease severity, and help to feed an increasingly hungry planet. PMID:27540383

  8. Immune signaling pathways activated in response to different pathogenic micro-organisms in Bombyx mori.

    PubMed

    Liu, Wei; Liu, Jiabin; Lu, Yahong; Gong, Yongchang; Zhu, Min; Chen, Fei; Liang, Zi; Zhu, Liyuan; Kuang, Sulan; Hu, Xiaolong; Cao, Guangli; Xue, Renyu; Gong, Chengliang

    2015-06-01

    The JAK/STAT, Toll, Imd, and RNAi pathways are the major signaling pathways associated with insect innate immunity. To explore the different immune signaling pathways triggered in response to pathogenic micro-organism infections in the silkworm, Bombyx mori, the expression levels of the signal transducer and activator of transcription (BmSTAT), spatzle-1 (Bmspz-1), peptidoglycan-recognition protein LB (BmPGRP-LB), peptidoglycan-recognition protein LE (BmPGRP-LE), argonaute 2 (Bmago2), and dicer-2 (Bmdcr2) genes after challenge with Escherichia coli (E. coli), Serratiamarcescens (Sm), Bacillus bombyseptieus (Bab), Beauveriabassiana (Beb), nucleopolyhedrovirus (BmNPV), cypovirus (BmCPV), bidensovirus (BmBDV), or Nosemabombycis (Nb) were determined using real-time PCR. We found that the JAK/STAT pathway could be activated by challenge with BmNPV and BmBDV, the Toll pathway could be most robustly induced by challenge with Beb, the Imd pathway was mainly activated in response to infection by E. coli and Sm, and the RNAi pathway was not activated by viral infection, but could be triggered by some bacterial infections. These findings yield insights into the immune signaling pathways activated in response to different pathogenic micro-organisms in the silkworm.

  9. Isolation of porphyran-degrading marine microorganisms from the surface of red alga, Porphyra yezoensis.

    PubMed

    Yoshimura, Takashi; Tsuge, Keisuke; Sumi, Toshihisa; Yoshiki, Masahiro; Tsuruta, Yumi; Abe, Shin-ichi; Nishino, Shiduo; Sanematsu, Seigo; Koganemaru, Kazuyoshi

    2006-04-01

    Marine microorganisms degrading porphyran (POR) were found on the surface of thalli of Porphyra yezoensis. Fifteen crude microorganism groups softened and liquefied the surface of agar-rich plate medium. Among these, 11 microorganism groups degraded porphyran that consisted of sulfated polysaccharide in Porphyra yezoensis. Following isolation, 7 POR-degradable microorganisms were isolated from the 11 POR-degradable microorganism groups.

  10. Screening of microorganisms from Antarctic surface water and cytotoxicity metabolites from Antarctic microorganisms.

    PubMed

    Zheng, Lanhong; Yang, Kangli; Liu, Jia; Sun, Mi; Zhu, Jiancheng; Lv, Mei; Kang, Daole; Wang, Wei; Xing, Mengxin; Li, Zhao

    2016-03-01

    The Antarctic is a potentially important library of microbial resources and new bioactive substances. In this study, microorganisms were isolated from surface water samples collected from different sites of the Antarctic. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay-based cytotoxicity-tracking method was used to identify Antarctic marine microorganism resources for antitumor lead compounds. The results showed that a total of 129 Antarctic microorganism strains were isolated. Twelve strains showed potent cytotoxic activities, among which a Gram-negative, rod-shaped bacterium, designated as N11-8 was further studied. Phylogenetic analysis based on 16S rRNA gene sequence showed that N11-8 belongs to the genus Bacillus. Fermented active products of N11-8 with molecular weights of 1-30 kDa had higher inhibitory effects on different cancaer cells, such as BEL-7402 human hepatocellular carcinoma cells, U251 human glioma cells, RKO human colon carcinoma cells, A549 human lung carcinoma cells, and MCF-7 human breast carcinoma cells. However, they displayed lower cytotoxicity against HFL1 human normal fibroblast lung cells. However, they displayed lower cytotoxicity against HFL1 human normal fibroblast lung cells. Microscopic observations showed that the fermented active products have inhibitory activity on BEL-7402 cells similar to that of mitomycin C. Further studies indicated that the fermented active products have high pH and high thermal stability. In conclusion, most strains isolated in this study may be developed as promising sources for the discovery of antitumor bioactive substances. The fermented active products of Antarctic marine Bacillus sp. N11- 8 are expected to be applied in the prevention and treatment of cancer.

  11. Autecology of microorganisms of typical Ecuador biotopes.

    PubMed

    Tashyrev, O B; Pidgorskyi, V S; Toro, Miguel Naranjo; Gualoto, Miguel; Gladka, G V; Tashyreva, H O; Rokitko, P V; Romanovskaya, V A

    2014-01-01

    34 strains of aerobic chemoorganotrophic microorganisms were isolated from 23 soil and plant samples selected from highland biotopes of Ecuador-Andes massif (Papallacta, 4020 m), ash at the foot of the volcano Tungurahua, mountainous jungle (La Favorita, 1600 m), as well as in humid tropic botanical garden (state Puyo, 950 m). In mountain jungle samples the high number of bacteria--10(5)-10(7) CFU/g of sample were represented by 2-5 morphotypes. In highland (4020 m) samples the bacterial counts made from 10(2) to 10(7) CFU/g of sample. The current study describes resistance of isolated strains to high salinity, UV radiation and toxic metal ions. The majority of isolated strains were halotolerant. Isolates from volcanic ash showed high resistance level to UV radiation--LD99,99 made 1000-1440 J/m2; resistance level for isolates from the soil of Puyo Botanical Garden and isolates from rock lichen (Papallacta) LD99,99 made 1160 and 800 J/m2 respectively. Strains isolated from mountain jungle (La Favorita) showed lower UV-resistance. In highland biotopes of Ecuador occurred bacteria resistant to toxic metal ions. The highest resistance to Hg2+ was shown by isolate of lichen from mountain jungle, the maximal growth concentration was 0.025 g/L; to Cr(VI)--by isolate from lichen rock massif--3,0 g/L. Correlation between metal-resistance, halotolerace and UV resistance for studied strains was not detected, probably because of different microbial cell damage/repair mechanisms under the action of these factors.

  12. Biodegradation of hexachlorocyclohexane (HCH) by microorganisms.

    PubMed

    Phillips, Theresa M; Seech, Alan G; Lee, Hung; Trevors, Jack T

    2005-08-01

    The organochlorine pesticide Lindane is the gamma-isomer of hexachlorocyclohexane (HCH). Technical grade Lindane contains a mixture of HCH isomers which include not only gamma-HCH, but also large amounts of predominantly alpha-, beta- and delta-HCH. The physical properties and persistence of each isomer differ because of the different chlorine atom orientations on each molecule (axial or equatorial). However, all four isomers are considered toxic and recalcitrant worldwide pollutants. Biodegradation of HCH has been studied in soil, slurry and culture media but very little information exists on in situ bioremediation of the different isomers including Lindane itself, at full scale. Several soil microorganisms capable of degrading, and utilizing HCH as a carbon source, have been reported. In selected bacterial strains, the genes encoding the enzymes involved in the initial degradation of Lindane have been cloned, sequenced, expressed and the gene products characterized. HCH is biodegradable under both oxic and anoxic conditions, although mineralization is generally observed only in oxic systems. As is found for most organic compounds, HCH degradation in soil occurs at moderate temperatures and at near neutral pH. HCH biodegradation in soil has been reported at both low and high (saturated) moisture contents. Soil texture and organic matter appear to influence degradation presumably by sorption mechanisms and impact on moisture retention, bacterial growth and pH. Most studies report on the biodegradation of relatively low (< 500 mg/kg) concentrations of HCH in soil. Information on the effects of inorganic nutrients, organic carbon sources or other soil amendments is scattered and inconclusive. More in-depth assessments of amendment effects and evaluation of bioremediation protocols, on a large scale, using soil with high HCH concentrations, are needed.

  13. Nitrogen acquisition by plants and microorganisms in a temperate grassland

    NASA Astrophysics Data System (ADS)

    Liu, Qianyuan; Qiao, Na; Xu, Xingliang; Xin, Xiaoping; Han, Jessie Yc; Tian, Yuqiang; Ouyang, Hua; Kuzyakov, Yakov

    2016-03-01

    Nitrogen (N) limitation is common in most terrestrial ecosystems, often leading to strong competition between microorganisms and plants. The mechanisms of niche differentiation to reduce this competition remain unclear. Short-term 15N experiments with NH4+, NO3‑, and glycine were conducted in July, August and September in a temperate grassland to evaluate the chemical, spatial and temporal niche differentiation by competition between plants and microorganisms for N. Microorganisms preferred NH4+ and NO3‑, while plants preferred NO3‑. Both plants and microorganisms acquired more N in August and September than in July. The soil depth had no significant effects on microbial uptake, but significantly affected plant N uptake. Plants acquired 67% of their N from the 0–5 cm soil layer and 33% from the 5–15 cm layer. The amount of N taken up by microorganisms was at least seven times than plants. Although microorganisms efficiently compete for N with plants, the competition is alleviated through chemical partitioning mainly in deeper soil layer. In the upper soil layer, neither chemical nor temporal niche separation is realized leading to strong competition between plants and microorganisms that modifies N dynamics in grasslands.

  14. Nitrogen acquisition by plants and microorganisms in a temperate grassland.

    PubMed

    Liu, Qianyuan; Qiao, Na; Xu, Xingliang; Xin, Xiaoping; Han, Jessie Yc; Tian, Yuqiang; Ouyang, Hua; Kuzyakov, Yakov

    2016-03-10

    Nitrogen (N) limitation is common in most terrestrial ecosystems, often leading to strong competition between microorganisms and plants. The mechanisms of niche differentiation to reduce this competition remain unclear. Short-term (15)N experiments with NH4(+), NO3(-), and glycine were conducted in July, August and September in a temperate grassland to evaluate the chemical, spatial and temporal niche differentiation by competition between plants and microorganisms for N. Microorganisms preferred NH4(+) and NO3(-), while plants preferred NO3(-). Both plants and microorganisms acquired more N in August and September than in July. The soil depth had no significant effects on microbial uptake, but significantly affected plant N uptake. Plants acquired 67% of their N from the 0-5 cm soil layer and 33% from the 5-15 cm layer. The amount of N taken up by microorganisms was at least seven times than plants. Although microorganisms efficiently compete for N with plants, the competition is alleviated through chemical partitioning mainly in deeper soil layer. In the upper soil layer, neither chemical nor temporal niche separation is realized leading to strong competition between plants and microorganisms that modifies N dynamics in grasslands.

  15. Nitrogen acquisition by plants and microorganisms in a temperate grassland

    PubMed Central

    Liu, Qianyuan; Qiao, Na; Xu, Xingliang; Xin, Xiaoping; Han, Jessie Yc; Tian, Yuqiang; Ouyang, Hua; Kuzyakov, Yakov

    2016-01-01

    Nitrogen (N) limitation is common in most terrestrial ecosystems, often leading to strong competition between microorganisms and plants. The mechanisms of niche differentiation to reduce this competition remain unclear. Short-term 15N experiments with NH4+, NO3−, and glycine were conducted in July, August and September in a temperate grassland to evaluate the chemical, spatial and temporal niche differentiation by competition between plants and microorganisms for N. Microorganisms preferred NH4+ and NO3−, while plants preferred NO3−. Both plants and microorganisms acquired more N in August and September than in July. The soil depth had no significant effects on microbial uptake, but significantly affected plant N uptake. Plants acquired 67% of their N from the 0–5 cm soil layer and 33% from the 5–15 cm layer. The amount of N taken up by microorganisms was at least seven times than plants. Although microorganisms efficiently compete for N with plants, the competition is alleviated through chemical partitioning mainly in deeper soil layer. In the upper soil layer, neither chemical nor temporal niche separation is realized leading to strong competition between plants and microorganisms that modifies N dynamics in grasslands. PMID:26961252

  16. Vibrational spectroscopy as a probe to rapidly detect, identify, and characterize micro-organisms

    NASA Astrophysics Data System (ADS)

    Sockalingum, Ganesh D.; Lamfarraj, Hasnae; Beljebbar, Abdelilah; Pina, Patrick; Delavenne, Marc; Witthuhn, Fabienne; Allouch, Pierre; Manfait, Michel

    1999-04-01

    Fast and exact identification of a great number of microorganisms is becoming a serious challenge. Differentiation and identification of microorganisms is today mainly achieved by the use of a variety of distinct techniques based on morphological, serological aspects and a set of biochemical test. Vibrational spectroscopic techniques can be complementary and useful methods in this field due to their rapidity, 'fingerprinting' capabilities, and the molecular information that they can provide. Using SERS at Ag colloids, we have conducted pilot studies to rapidly detect and identify bacterial clinical strains. Using a Raman microspectrometer equipped with a He/Ne laser, a first attempt to record SERS spectra was made on colloidal solutions. Spectra were of good quality but not very reproducible due to the movement of the microorganisms. Strains were then put in presence of Ag colloids and direct on-plate analysis was performed. Spectra were more reproducible, with diminished fluorescence, and reveal characteristic cellular-level information. Different growth conditions and colloid preparations have been tested. Pseudomonas aeruginosa and Escherichia coli clinical strains, responsible for nosocomial infections, have been our first test samples. An attempt has also been made to record SERS data from gold colloids in view of future measurement in the near-IR. Spectroscopic data are compared with ATR-FTIR results.

  17. Presidential Green Chemistry Challenge: 2010 Academic Award - James C. Liao and Easel Biotechnologies, LLC

    EPA Pesticide Factsheets

    Presidential Green Chemistry Challenge 2010 award winner, Dr. James C. Liao, genetically engineered microorganisms to make higher alcohols (with 3 to 8 carbon atoms) from glucose or directly from carbon dioxide (CO2).

  18. Antimicrobial Compounds from Marine Invertebrates-Derived Microorganisms.

    PubMed

    Liu, Juan; Jung, Jee H; Liu, Yonghong

    2016-01-01

    It is known that marine invertebrates, including sponges, tunicates, cnidaria or mollusks, host affluent and various communities of symbiotic microorganisms. The microorganisms associated with the invertebrates metabolized various biologically active compounds, which could be an important resource for the discovery and development of potentially novel drugs. In this review, the new compounds with antimicrobial activity isolated from marine invertebrate-derived microorganisms in the last decade (2004-2014) will be presented, with focus on the relevant antimicrobial activities, origin of isolation, and information of strain species. New compounds without antimicrobial activity were not revealed.

  19. Clostridiumm ljungdahlii, an anaerobic ethanol and acetate producing microorganism

    DOEpatents

    Gaddy, James L.; Clausen, Edgar C.

    1992-01-01

    A newly discovered microorganism was isolated in a biologically pure culture and designated Clostridium ljungdahlii, having the identifying characteristics of ATCC No. 49587. Cultured in an aqueous nutrient medium under anaerobic conditions, this microorganism is capable of producing ethanol and acetate from CO and H.sub.2 O and/or CO.sub.2 and H.sub.2 in synthesis gas. Under optimal growth conditions, the microorganism produces acetate in preference to ethanol. Conversely, under non-growth conditions, ethanol production is favored over acetate.

  20. Clostridiumm ljungdahlii, an anaerobic ethanol and acetate producing microorganism

    DOEpatents

    Gaddy, J.L.; Clausen, E.C.

    1992-12-22

    A newly discovered microorganism was isolated in a biologically pure culture and designated Clostridium ljungdahlii, having the identifying characteristics of ATCC No. 49587. Cultured in an aqueous nutrient medium under anaerobic conditions, this microorganism is capable of producing ethanol and acetate from CO and H[sub 2]O and/or CO[sub 2] and H[sub 2] in synthesis gas. Under optimal growth conditions, the microorganism produces acetate in preference to ethanol. Conversely, under non-growth conditions, ethanol production is favored over acetate. 3 figs.

  1. Modeling microorganism transport and survival in the subsurface.

    PubMed

    Bradford, Scott A; Wang, Yusong; Kim, Hyunjung; Torkzaban, Saeed; Šimůnek, Jiri

    2014-03-01

    An understanding of microbial transport and survival in the subsurface is needed for public health, environmental applications, and industrial processes. Much research has therefore been directed to quantify mechanisms influencing microbial fate, and the results demonstrate a complex coupling among many physical, chemical, and biological factors. Mathematical models can be used to help understand and predict the complexities of microbial transport and survival in the subsurface under given assumptions and conditions. This review highlights existing model formulations that can be used for this purpose. In particular, we discuss models based on the advection-dispersion equation, with terms for kinetic retention to solid-water and/or air-water interfaces; blocking and ripening; release that is dependent on the resident time, diffusion, and transients in solution chemistry, water velocity, and water saturation; and microbial decay (first-order and Weibull) and growth (logistic and Monod) that is dependent on temperature, nutrient concentration, and/or microbial concentration. We highlight a two-region model to account for microbe migration in the vicinity of a solid phase and use it to simulate the coupled transport and survival of species under a variety of environmentally relevant scenarios. This review identifies challenges and limitations of models to describe and predict microbial transport and survival. In particular, many model parameters have to be optimized to simulate a diversity of observed transport, retention, and survival behavior at the laboratory scale. Improved theory and models are needed to predict the fate of microorganisms in natural subsurface systems that are highly dynamic and heterogeneous.

  2. The radiocarbon signature of microorganisms in the mesopelagic ocean

    PubMed Central

    Hansman, Roberta L.; Griffin, Sheila; Watson, Jordan T.; Druffel, Ellen R. M.; Ingalls, Anitra E.; Pearson, Ann; Aluwihare, Lihini I.

    2009-01-01

    Several lines of evidence indicate that microorganisms in the meso- and bathypelagic ocean are metabolically active and respiring carbon. In addition, growing evidence suggests that archaea are fixing inorganic carbon in this environment. However, direct quantification of the contribution from deep ocean carbon sources to community production in the dark ocean remains a challenge. In this study, carbon flow through the microbial community at 2 depths in the mesopelagic zone of the North Pacific Subtropical Gyre was examined by exploiting the unique radiocarbon signatures (Δ14C) of the 3 major carbon sources in this environment. The radiocarbon content of nucleic acids, a biomarker for viable cells, isolated from size-fractionated particles (0.2–0.5 μm and >0.5 μm) showed the direct incorporation of carbon delivered by rapidly sinking particles. Most significantly, at the 2 mesopelagic depths examined (670 m and 915 m), carbon derived from in situ autotrophic fixation supported a significant fraction of the free-living microbial community (0.2–0.5 μm size fraction), but the contribution of chemoautotrophy varied markedly between the 2 depths. Results further showed that utilization of the ocean's largest reduced carbon reservoir, 14C-depleted, dissolved organic carbon, was negligible in this environment. This isotopic portrait of carbon assimilation by the in situ, free-living microbial community, integrated over >50,000 L of seawater, implies that recent, photosynthetic carbon is not always the major carbon source supporting microbial community production in the mesopelagic realm. PMID:19366673

  3. Anaerobic digestion of lignocellulosic biomass: challenges and opportunities.

    PubMed

    Sawatdeenarunat, Chayanon; Surendra, K C; Takara, Devin; Oechsner, Hans; Khanal, Samir Kumar

    2015-02-01

    Anaerobic digestion (AD) of lignocellulosic biomass provides an excellent opportunity to convert abundant bioresources into renewable energy. Rumen microorganisms, in contrast to conventional microorganisms, are an effective inoculum for digesting lignocellulosic biomass due to their intrinsic ability to degrade substrate rich in cellulosic fiber. However, there are still several challenges that must be overcome for the efficient digestion of lignocellulosic biomass. Anaerobic biorefinery is an emerging concept that not only generates bioenergy, but also high-value biochemical/products from the same feedstock. This review paper highlights the current status of lignocellulosic biomass digestion and discusses its challenges. The paper also discusses the future research needs of lignocellulosic biomass digestion.

  4. Toxicological impacts of antibiotics on aquatic micro-organisms: A mini-review.

    PubMed

    Välitalo, Pia; Kruglova, Antonina; Mikola, Anna; Vahala, Riku

    2017-02-22

    Antibiotics are found globally in the environment at trace levels due to their extensive consumption, which raises concerns about the effects they can have on non-target organisms, especially environmental micro-organisms. So far the majority of studies have focused on different aspects of antibiotic resistance or on analyzing the occurrence, fate, and removal of antibiotics from hospital and municipal wastewaters. Little attention has been paid to ecotoxicological effects of antibiotics on aquatic micro-organisms although they play a critical role in most ecosystems and they are potentially sensitive to these substances. Here we review the current state of research on the toxicological impacts of antibiotics to aquatic micro-organisms, including proteobacteria, cyanobacteria, algae and bacteria commonly present in biological wastewater treatment processes. We focus on antibiotics that are poorly removed during wastewater treatment and thus end up in surface waters. We critically discuss and compare the available analytical methods and test organisms based on effect concentrations and identify the knowledge gaps and future challenges. We conclude that, in general, cyanobacteria and ammonium oxidizing bacteria are the most sensitive micro-organisms to antibiotics. It is important to include chronic tests in ecotoxicological assessment, because acute tests are not always appropriate in case of low sensitivity (for example for proteobacteria). However, the issue of rapid development of antibiotic resistance should be regarded in chronic testing. Furthermore, the application of other species of bacteria and endpoints should be considered in the future, not forgetting the mixture effect and bacterial community studies. Due to differences in the sensitivity of different test organisms to individual antibiotic substances, the application of several bioassays with varying test organisms would provide more comprehensive data for the risk assessment of antibiotics

  5. Marine microorganisms as potential biofactories for synthesis of metallic nanoparticles.

    PubMed

    Manivasagan, Panchanathan; Nam, Seung Yun; Oh, Junghwan

    2016-11-01

    The use of marine microorganisms as potential biofactories for green synthesis of metallic nanoparticles is a relatively new field of research with considerable prospects. This method is eco-friendly, time saving, and inexpensive and can be easily scaled up for large-scale synthesis. The increasing need to develop simple, nontoxic, clean, and environmentally safe production methods for nanoparticles and to decrease environmental impact, minimize waste, and increase energy productivity has become important in this field. Marine microorganisms are tiny organisms that live in marine ecosystems and account for >98% of biomass of the world's ocean. Marine microorganisms synthesize metallic nanoparticles either intracellularly or extracellularly. Marine microbially-produced metallic nanoparticles have received considerable attention in recent years because of their expected impact on various applications such as medicine, energy, electronic, and space industries. The present review discusses marine microorganisms as potential biofactories for the green synthesis of metallic nanoparticles and their potential applications.

  6. Multiorganismal Insects: Diversity and Function of Resident Microorganisms

    PubMed Central

    Douglas, Angela E.

    2015-01-01

    All insects are colonized by microorganisms on the insect exoskeleton, in the gut and hemocoel, and within insect cells. The insect microbiota is generally different from microorganisms in the external environment, including ingested food. Specifically, certain microbial taxa are favored by the conditions and resources in the insect habitat, by their tolerance of insect immunity, and by specific mechanisms for their transmission. The resident microorganisms can promote insect fitness by contributing to nutrition, especially by providing essential amino acids, B vitamins, and, for fungal partners, sterols. Some microorganisms protect their insect hosts against pathogens, parasitoids, and other parasites by synthesizing specific toxins or modifying the insect immune system. Priorities for future research include elucidation of microbial contributions to detoxification, especially of plant allelochemicals in phytophagous insects, and resistance to pathogens; as well as their role in among-insect communication; and the potential value of manipulation of the microbiota to control insect pests. PMID:25341109

  7. [Bio-active substances derived from marine microorganisms].

    PubMed

    Liu, Quanyong; Hu, Jiangchun; Xue, Delin; Ma, Chengxin; Wang, Shujin

    2002-07-01

    Marine microorganisms, which are taxonomically diverse and genetically special, have powerful potential in producing novel bio-active substances. This article summarized research progress in this respect. The results showed that marine bacteria which are main marine microorganism flora can produce rich kinds of bio-active substances and that even though marine actinomycetes and marine fungi are not as many as marine bacteria in species and quantity, they should be paid no less attention about their bio-active substances. Besides, present research are limited to those marine microorganisms which are easily cultured. One of the future research trends will be focused on bio-active substances derived from non-culturable marine microorganisms.

  8. Recovery of microorganisms from potentially lethal radiation damage

    NASA Astrophysics Data System (ADS)

    Borsa, Joseph; Lucht, Lisa; Blank, Greg

    1995-02-01

    Dose response curves for inactivation of microorganisms are central in the design of any process intending to use irradiation for the improvement of the microbiological quality of any treated materials, be it food or medical supplies. Under some conditions a fraction of irradiated microorganisms is able to recover from a potentially lethal dose. This recovery phenomenon must be considered in determining the efficacy of irradiation in microbial inactivation. In this work the recovery phenomenon was examined in eleven species of microorganisms. Variables examined included dose, radiation type, post-irradiation holding temperature, and nutritient medium used to culture the organism. Kinetics of damage repair and fixation were also examined. Results indicate that, for certain species of microorganisms, recovery can significantly lower the killing efficacy of irradiation.

  9. MICROORGANISMS IN BIOSOLIDS: ANALYTICAL METHODS DEVELOPMENT, STANDARDIZATION, AND VALIDATION

    EPA Science Inventory

    The objective of this presentation is to discuss pathogens of concern in biosolids, the analytical techniques used to evaluate microorganisms in biosolids, and to discuss standardization and validation of analytical protocols for microbes within such a complex matrix. Implicatio...

  10. Effective Dynamics of Microorganisms That Interact with Their Own Trail

    NASA Astrophysics Data System (ADS)

    Kranz, W. Till; Gelimson, Anatolij; Zhao, Kun; Wong, Gerard C. L.; Golestanian, Ramin

    2016-07-01

    Like ants, some microorganisms are known to leave trails on surfaces to communicate. We explore how trail-mediated self-interaction could affect the behavior of individual microorganisms when diffusive spreading of the trail is negligible on the time scale of the microorganism using a simple phenomenological model for an actively moving particle and a finite-width trail. The effective dynamics of each microorganism takes on the form of a stochastic integral equation with the trail interaction appearing in the form of short-term memory. For a moderate coupling strength below an emergent critical value, the dynamics exhibits effective diffusion in both orientation and position after a phase of superdiffusive reorientation. We report experimental verification of a seemingly counterintuitive perpendicular alignment mechanism that emerges from the model.

  11. Microorganisms meet solid minerals: interactions and biotechnological applications.

    PubMed

    Ng, Daphne H P; Kumar, Amit; Cao, Bin

    2016-08-01

    In natural and engineered environments, microorganisms often co-exist and interact with various minerals or mineral-containing solids. Microorganism-mineral interactions contribute significantly to environmental processes, including biogeochemical cycles in natural ecosystems and biodeterioration of materials in engineered environments. In this mini-review, we provide a summary of several key mechanisms involved in microorganism-mineral interactions, including the following: (i) solid minerals serve as substrata for biofilm development; (ii) solid minerals serve as an electron source or sink for microbial respiration; (iii) solid minerals provide microorganisms with macro or micronutrients for cell growth; and (iv) (semi)conductive solid minerals serve as extracellular electron conduits facilitating cell-to-cell interactions. We also highlight recent developments in harnessing microbe-mineral interactions for biotechnological applications.

  12. Multiorganismal insects: diversity and function of resident microorganisms.

    PubMed

    Douglas, Angela E

    2015-01-07

    All insects are colonized by microorganisms on the insect exoskeleton, in the gut and hemocoel, and within insect cells. The insect microbiota is generally different from microorganisms in the external environment, including ingested food. Specifically, certain microbial taxa are favored by the conditions and resources in the insect habitat, by their tolerance of insect immunity, and by specific mechanisms for their transmission. The resident microorganisms can promote insect fitness by contributing to nutrition, especially by providing essential amino acids, B vitamins, and, for fungal partners, sterols. Some microorganisms protect their insect hosts against pathogens, parasitoids, and other parasites by synthesizing specific toxins or modifying the insect immune system. Priorities for future research include elucidation of microbial contributions to detoxification, especially of plant allelochemicals in phytophagous insects, and resistance to pathogens; as well as their role in among-insect communication; and the potential value of manipulation of the microbiota to control insect pests.

  13. Indigenous microorganisms production and the effect on composting process

    NASA Astrophysics Data System (ADS)

    Abu-Bakar, Nurul-Ain; Ibrahim, Nazlina

    2013-11-01

    In this study, production of indigenous microorganisms (IMO) and effect on addition of IMO in composting process were done. Production of IMO was done in a series of steps to allow propagation of beneficial microorganisms. Effect of IMO addition in composting process was investigated by having 4 treatments; 1) rice straw without IMO nor manure and rice bran, 2) rice straw with IMO only, 3) rice straw with manure and rice bran, 4) rice straw with IMO, manure and rice bran. Production of IMO using cooked rice yields white molds. Addition of IMO during composting did not affect temperature increment. However, there were differences in numbers of microorganisms found during each stages of composting. Initial composting stage was dominated by mesophilic bacteria and actinomycetes, followed by thermophilic bacteria and later by actinomycetes upon composting completion. In conclusion, this study showed that IMO addition in composting increased microorganisms which are responsible in organic decomposition.

  14. Establishing Drug Resistance in Microorganisms by Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Demirev, Plamen A.; Hagan, Nathan S.; Antoine, Miquel D.; Lin, Jeffrey S.; Feldman, Andrew B.

    2013-08-01

    A rapid method to determine drug resistance in bacteria based on mass spectrometry is presented. In it, a mass spectrum of an intact microorganism grown in drug-containing stable isotope-labeled media is compared with a mass spectrum of the intact microorganism grown in non-labeled media without the drug present. Drug resistance is determined by predicting characteristic mass shifts of one or more microorganism biomarkers using bioinformatics algorithms. Observing such characteristic mass shifts indicates that the microorganism is viable even in the presence of the drug, thus incorporating the isotopic label into characteristic biomarker molecules. The performance of the method is illustrated on the example of intact E. coli, grown in control (unlabeled) and 13C-labeled media, and analyzed by MALDI TOF MS. Algorithms for data analysis are presented as well.

  15. Establishing drug resistance in microorganisms by mass spectrometry.

    PubMed

    Demirev, Plamen A; Hagan, Nathan S; Antoine, Miquel D; Lin, Jeffrey S; Feldman, Andrew B

    2013-08-01

    A rapid method to determine drug resistance in bacteria based on mass spectrometry is presented. In it, a mass spectrum of an intact microorganism grown in drug-containing stable isotope-labeled media is compared with a mass spectrum of the intact microorganism grown in non-labeled media without the drug present. Drug resistance is determined by predicting characteristic mass shifts of one or more microorganism biomarkers using bioinformatics algorithms. Observing such characteristic mass shifts indicates that the microorganism is viable even in the presence of the drug, thus incorporating the isotopic label into characteristic biomarker molecules. The performance of the method is illustrated on the example of intact E. coli, grown in control (unlabeled) and (13)C-labeled media, and analyzed by MALDI TOF MS. Algorithms for data analysis are presented as well.

  16. Technologies for Beneficial Microorganisms Inocula Used as Biofertilizers

    PubMed Central

    Malusá, E.; Sas-Paszt, L.; Ciesielska, J.

    2012-01-01

    The increasing need for environmentaly friendly agricultural practices is driving the use of fertilizers based on beneficial microorganisms. The latter belong to a wide array of genera, classes, and phyla, ranging from bacteria to yeasts and fungi, which can support plant nutrition with different mechanisms. Moreover, studies on the interactions between plant, soil, and the different microorganisms are shedding light on their interrelationships thus providing new possible ways to exploit them for agricultural purposes. However, even though the inoculation of plants with these microorganisms is a well-known practice, the formulation of inocula with a reliable and consistent effect under field conditions is still a bottleneck for their wider use. The choice of the technology for inocula production and of the carrier for the formulation is key to their successful application. This paper focuses on how inoculation issues can be approached to improve the performance of beneficial microorganisms used as a tool for enhancing plant growth and yield. PMID:22547984

  17. Microorganisms having enhanced resistance to acetate and methods of use

    DOEpatents

    Brown, Steven D; Yang, Shihui

    2014-10-21

    The present invention provides isolated or genetically modified strains of microorganisms that display enhanced resistance to acetate as a result of increased expression of a sodium proton antiporter. The present invention also provides methods for producing such microbial strains, as well as related promoter sequences and expression vectors. Further, the present invention provides methods of producing alcohol from biomass materials by using microorganisms with enhanced resistance to acetate.

  18. Marine Microorganisms: perspectives for getting involved in cellulosic ethanol.

    PubMed

    Intriago, Pablo

    2012-08-29

    The production of ethanol has been considered as an alternative to replace part of the petroleum derivate. Brazil and the US are the leading producers, but more environmentally friendly alternatives are needed. Lignocellulose has an enormous potential but technology has to be still improve in order to economically produce ethanol. The present paper reviews the potential and problems of this technology and proposes the study of a group of microorganisms with the largest genetic pool, marine microorganism.

  19. Rotary Apparatus Concentrates And Separates Micro-Organisms

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1992-01-01

    Apparatus concentrates and separates swimming micro-organisms of different species into concentric rings in fluid. Fluid containing high concentration of desired species removed by use of small scoop placed into fluid at radius of one of rings formed by that species. Micro-organisms concentrated into concentric rings by combined dynamic effects of upward and horizontal components of swimming, rotation of dish, gravitation, and viscosity.

  20. Marine Microorganisms: perspectives for getting involved in cellulosic ethanol

    PubMed Central

    2012-01-01

    The production of ethanol has been considered as an alternative to replace part of the petroleum derivate. Brazil and the US are the leading producers, but more environmentally friendly alternatives are needed. Lignocellulose has an enormous potential but technology has to be still improve in order to economically produce ethanol. The present paper reviews the potential and problems of this technology and proposes the study of a group of microorganisms with the largest genetic pool, marine microorganism. PMID:22931793

  1. Microorganisms having enhanced tolerance to inhibitors and stress

    SciTech Connect

    Brown, Steven D.; Yang, Shihui

    2014-07-29

    The present invention provides genetically modified strains of microorganisms that display enhanced tolerance to stress and/or inhibitors such as sodium acetate and vanillin. The enhanced tolerance can be achieved by increasing the expression of a protein of the Sm-like superfamily such as a bacterial Hfq protein and a fungal Sm or Lsm protein. Further, the present invention provides methods of producing alcohol from biomass materials by using the genetically modified microorganisms of the present invention.

  2. Method for treating wastewater using microorganisms and vascular aquatic plants

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C. (Inventor)

    1983-01-01

    A method for treating wastewater compresses subjecting the wastewater to an anaerobic setting step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner. There the effluent is subjected first to the action of anaerobic and facultative microorganisms, and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.

  3. New therapeutic approaches by using microorganism-derived compounds.

    PubMed

    Amedei, A; D'Elios, M M

    2012-01-01

    The role of natural products as a source for remedies has been recognized since ancient times. Despite major scientific and technological progress in combinatorial chemistry, drugs derived from natural product still make an enormous contribution to drug discovery today. Nature is an attractive source of new therapeutic candidate compounds since a tremendous chemical diversity is found in millions of species of plants, animals, marine organisms and microorganisms. Microorganisms such as bacteria and fungi have been invaluable to discover drugs and lead compounds. These microorganisms produce a large variety of antimicrobial agents which have evolved to give their hosts an advantage over their competitors in the microbiological world. The screening of microorganisms became highly popular after the discovery of penicillin but in recent years the list of antibacterial agents (bacteria- or fungi-derived) has increased considerably with the arrival of cephalosporins, tetracyclines, aminoglycosides, rifamycins, and chloramphenicol. Although most of the drugs derived from microorganisms are used in antibacterial therapy, some microbial metabolites have provided lead compounds in other fields of medicine. For example: the fungal metabolite lovastatin, which was the lead compound for a series of drugs that lower cholesterol levels, the ciclosporin (fungal metabolite) currently used to suppress the immune response after transplantation operations and sirolimus- a bacterium-derived macrolide- used in the treatment of some cancers. The aim of this review is to analyze the current uses and the future applications in therapeutic treatments of microorganism-derived products (MdPs) and discuss the results obtained in the some clinical trials.

  4. Quantity analysis of micro-organisms in bottled water

    NASA Astrophysics Data System (ADS)

    Li, Juan; Li, Xiangyong

    2008-12-01

    Water is necessary to human being and all kinds of animals and plants. In recently years, Bottled Water become the main drinking water whatever for families or for institutions. But most of them have no conception of the water's safety or quality. To have conceptions of the count and distributing of the microorganisms in bucket pure water, we use fluorescent microscope counting stained with SYBR Green I to research the microorganisms (including virus) quantity in Bottled Water for six samples produced in different place. Analyzing shows that the quantity of the microorganisms in these water are different. Some up to 11.912×106 virus/ m L. The quality of Bottled Water needs to be improved. And the quantity of microorganisms in the water is different with different ways to keep the water. At the same time, it shows that fluorescent microscope counting stained with SYBR Green I method is simple and high sensitive to such low microorganisms quantity water sample. It can be used in the microorganisms dynamic quantity research in drinking water.

  5. Evaluation of the ecotoxicity of pollutants with bioluminescent microorganisms.

    PubMed

    Fernández-Piñas, Francisca; Rodea-Palomares, Ismael; Leganés, Francisco; González-Pleiter, Miguel; Angeles Muñoz-Martín, M

    2014-01-01

    This chapter deals with the use of bioluminescent microorganisms in environmental monitoring, particularly in the assessment of the ecotoxicity of pollutants. Toxicity bioassays based on bioluminescent microorganisms are an interesting complement to classical toxicity assays, providing easiness of use, rapid response, mass production, and cost effectiveness. A description of the characteristics and main environmental applications in ecotoxicity testing of naturally bioluminescent microorganisms, covering bacteria and eukaryotes such as fungi and dinoglagellates, is reported in this chapter. The main features and applications of a wide variety of recombinant bioluminescent microorganisms, both prokaryotic and eukaryotic, are also summarized and critically considered. Quantitative structure-activity relationship models and hormesis are two important concepts in ecotoxicology; bioluminescent microorganisms have played a pivotal role in their development. As pollutants usually occur in complex mixtures in the environment, the use of both natural and recombinant bioluminescent microorganisms to assess mixture toxicity has been discussed. The main information has been summarized in tables, allowing quick consultation of the variety of luminescent organisms, bioluminescence gene systems, commercially available bioluminescent tests, environmental applications, and relevant references.

  6. Environmental challenge

    SciTech Connect

    Conable, B.; Warford, J.; Partow, Z.; Lutz, E.; Munasinghe, M.

    1991-09-01

    The contents include the following: Development and the Environment: A Global Balance; Evolution of the World Bank's Environmental Policy; Accounting for the Environment; Public Policy and the Environment; Managing Drylands; Environmental Action Plans in Africa; Agroforestry in Sub-Saharan Africa; Irrigation and the Environmental Challenge; Curbing Pollution in Developing Countries; Global Warming and the Developing World; and The Global Environment Facility.

  7. Challenging Behavior.

    ERIC Educational Resources Information Center

    Reichle, Joe, Ed.; DePaepe, Paris, Ed.

    1991-01-01

    The articles in this feature or theme issue describe successful approaches to positive, community-based management of severe challenging behavior. Programs include: a train-the-trainer strategy for inservice training used across the country; the use of student volunteers as community integration facilitators; a school-based intervention project…

  8. Quill Challenge

    ERIC Educational Resources Information Center

    Stevens, Lori

    2006-01-01

    Teaching high school students the "grammar" of art--the principles and elements of art and design--while also teaching them about creativity and concept can be difficult. This author has found that combining beginning lessons in line, shape, value, texture, form, and color with projects requiring innovation and inspiration, though challenging, is…

  9. Fluid flow enhances the effectiveness of toxin export by aquatic microorganisms: a first-passage perspective

    NASA Astrophysics Data System (ADS)

    Licata, Nicholas; Clark, Aaron

    2014-03-01

    Aquatic microorganisms face a variety of challenges in the course of development. One central challenge is efficiently regulating the export of toxic molecules inside the developing embryo. The strategies employed should be robust with respect to the variable ocean environment and limit the chances that exported toxins are reabsorbed. In this talk we consider the first-passage problem for the uptake of exported toxins by a spherical embryo. A perturbative solution of the advection-diffusion equation reveals that a concentration boundary layer forms in the vicinity of the embryo, and that fluid flow enhances the effectiveness of toxin export. We highlight connections between the model results and recent experiments on the development of sea urchin embryos. We acknowledge financial support from the University of Michigan-Dearobrn CASL Faculty Summer Research Grant.

  10. Plasma and salivary amoxicillin concentrations and effect against oral microorganisms.

    PubMed

    Baglie, S; Del Ruenis, A P Bortolo; Motta, R H Lopes; Baglie, R C Catelli; Franco, G C Nobre; Franco, L M; Rosalen, P L; Silva, P; Groppo, F C

    2007-10-01

    Plasma and salivary amoxicillin (AMO) concentrations were quantified following a single oral dose (875 mg) of two formulations of AMO (Amoxicillin-EMS Sigma Pharma and Amoxil BD 875 mg). In addition, the effect of amoxicillin against oral microorganisms was accessed. The open, randomized, two-period crossover study was carried out in 20 volunteers. Saliva and blood samples were collected at 0, 0.5, 1, 2, 4, 8 and 12 h after drug administration, and quantified using HPLC-ESI-MS and HPLC, respectively. Streptococci counts, anaerobe counts and total microorganism counts were obtained. No differences were observed between formulations (p > 0.05) in the plasma and salivary AMO concentrations and the pharmacokinetic parameters (C(max), t(max), AUC(0-8), and AUC(0-infinity)) also showed no statistically significant differences between formulations (p > 0.05). Microorganism counts for the two formulations at all sampling times did not differ (p > 0.05) but all microorganism counts at 60 min post-dose showed a significant decrease (p < 0.05). Amoxicillin was effective in reducing oral microorganism levels up to 12 h post-dose.

  11. Response of microorganisms to a simulated Martian environment.

    PubMed

    Hawrylewicz, E J; Hagen, C A; Ehrlich, R

    1965-01-01

    A study was undertaken to determine whether terrestrial microorganisms can survive in a simulated Martian environment. The ultimate objective is to establish whether earth organisms can contaminate Mars. In addition, any demonstration of survival and growth in a simulated Martian environment will provide information relating to the biology of Mars. In the experimental design, exhaustive consideration was given to the duplication of the known and the theoretical environmental parameters of Mars. These included composition of the soil and the atmosphere, barometric pressure, moisture content, solar radiation, and diurnal temperature extremes. Based upon these considerations, a simulated Martian summer environment was defined and used in the experiments. One group of microorganisms was selected from culture collections on the basis of their known characteristics. The other group was made of microorganisms isolated from soils. The soil samples were obtained from the Antarctic, from New Mexico, and California deserts, and from the Colorado tundra. The studies showed that a number of microorganisms can survive the simulated Martian environment. However, no substantial growth under such conditions could be demonstrated. The ability of microorganisms to form spores as a mechanism for survival will be discussed. Also, experiments utilizing augmented environments to establish minimum environmental conditions which will permit growth will be described.

  12. [Effects of transgenic crops on soil microorganisms: a review].

    PubMed

    Zhang, Yan-Jun; Xie, Ming; Peng, De-Liang

    2013-09-01

    The worldwide cultivation of transgenic crops not only provides tremendous economic benefits, but also induces the concern about the potential risks of transgenic crops on soil ecosystem in which microorganisms are involved. The potential effects of transgenic crops on soil microorganisms include the direct effects of the transgenic proteins on non-target soil microorganisms, and the indirect effects of the unintentional changes in the chemical compositions of root exudates induced by the introduction of the exogenous transgenic proteins. Most of the studies on transgenic crops suggested that transgenic crops could affect the quantity and structure of soil microbial populations. However, the perceivable effects on the soil microorganisms are inconsistent, with some in significant and others in non-significant, or some with persistent and others with non-persistent. This paper summarized the effects of different transgenic crops on soil microorganisms, and discussed the factors affecting the assessment reliability, including the species of transgenic crops and the experimental technologies and principles. Some issues needed to be paid special attention to in the future studies were put forward.

  13. Interplay between microorganisms and geochemistry in geological carbon storage

    SciTech Connect

    Altman, Susan J.; Kirk, Matthew Fletcher; Santillan, Eugenio-Felipe U.; Bennett, Philip C.

    2016-02-28

    Researchers at the Center for Frontiers of Subsurface Energy Security (CFSES) have conducted laboratory and modeling studies to better understand the interplay between microorganisms and geochemistry for geological carbon storage (GCS). We provide evidence of microorganisms adapting to high pressure CO2 conditions and identify factors that may influence survival of cells to CO2 stress. Factors that influenced the ability of cells to survive exposure to high-pressure CO2 in our experiments include mineralogy, the permeability of cell walls and/or membranes, intracellular buffering capacity, and whether cells live planktonically or within biofilm. Column experiments show that, following exposure to acidic water, biomass can remain intact in porous media and continue to alter hydraulic conductivity. Our research also shows that geochemical changes triggered by CO2 injection can alter energy available to populations of subsurface anaerobes and that microbial feedbacks on this effect can influence carbon storage. Our research documents the impact of CO2 on microorganisms and in turn, how subsurface microorganisms can influence GCS. Furthermore, we conclude that microbial presence and activities can have important implications for carbon storage and that microorganisms should not be overlooked in further GCS research.

  14. Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia

    PubMed Central

    Avellaneda-Torres, Lizeth Manuela; Pulido, Claudia Patricia Guevara; Rojas, Esperanza Torres

    2014-01-01

    A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP), Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS) of ribosomal DNA for fungi. Multivariate statistical analysis (MVA) was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment. PMID:25763024

  15. Interplay between microorganisms and geochemistry in geological carbon storage

    DOE PAGES

    Altman, Susan J.; Kirk, Matthew Fletcher; Santillan, Eugenio-Felipe U.; ...

    2016-02-28

    Researchers at the Center for Frontiers of Subsurface Energy Security (CFSES) have conducted laboratory and modeling studies to better understand the interplay between microorganisms and geochemistry for geological carbon storage (GCS). We provide evidence of microorganisms adapting to high pressure CO2 conditions and identify factors that may influence survival of cells to CO2 stress. Factors that influenced the ability of cells to survive exposure to high-pressure CO2 in our experiments include mineralogy, the permeability of cell walls and/or membranes, intracellular buffering capacity, and whether cells live planktonically or within biofilm. Column experiments show that, following exposure to acidic water, biomassmore » can remain intact in porous media and continue to alter hydraulic conductivity. Our research also shows that geochemical changes triggered by CO2 injection can alter energy available to populations of subsurface anaerobes and that microbial feedbacks on this effect can influence carbon storage. Our research documents the impact of CO2 on microorganisms and in turn, how subsurface microorganisms can influence GCS. Furthermore, we conclude that microbial presence and activities can have important implications for carbon storage and that microorganisms should not be overlooked in further GCS research.« less

  16. Biosurfactants Produced by Marine Microorganisms with Therapeutic Applications

    PubMed Central

    Gudiña, Eduardo J.; Teixeira, José A.; Rodrigues, Lígia R.

    2016-01-01

    Marine microorganisms possess unique metabolic and physiological features and are an important source of new biomolecules, such as biosurfactants. Some of these surface-active compounds synthesized by marine microorganisms exhibit antimicrobial, anti-adhesive and anti-biofilm activity against a broad spectrum of human pathogens (including multi-drug resistant pathogens), and could be used instead of existing drugs to treat infections caused by them. In other cases, these biosurfactants show anti-cancer activity, which could be envisaged as an alternative to conventional therapies. However, marine biosurfactants have not been widely explored, mainly due to the difficulties associated with the isolation and growth of their producing microorganisms. Culture-independent techniques (metagenomics) constitute a promising approach to study the genetic resources of otherwise inaccessible marine microorganisms without the requirement of culturing them, and can contribute to the discovery of novel biosurfactants with significant biological activities. This paper reviews the most relevant biosurfactants produced by marine microorganisms with potential therapeutic applications and discusses future perspectives and opportunities to discover novel molecules from marine environments. PMID:26901207

  17. Biosurfactants Produced by Marine Microorganisms with Therapeutic Applications.

    PubMed

    Gudiña, Eduardo J; Teixeira, José A; Rodrigues, Lígia R

    2016-02-18

    Marine microorganisms possess unique metabolic and physiological features and are an important source of new biomolecules, such as biosurfactants. Some of these surface-active compounds synthesized by marine microorganisms exhibit antimicrobial, anti-adhesive and anti-biofilm activity against a broad spectrum of human pathogens (including multi-drug resistant pathogens), and could be used instead of existing drugs to treat infections caused by them. In other cases, these biosurfactants show anti-cancer activity, which could be envisaged as an alternative to conventional therapies. However, marine biosurfactants have not been widely explored, mainly due to the difficulties associated with the isolation and growth of their producing microorganisms. Culture-independent techniques (metagenomics) constitute a promising approach to study the genetic resources of otherwise inaccessible marine microorganisms without the requirement of culturing them, and can contribute to the discovery of novel biosurfactants with significant biological activities. This paper reviews the most relevant biosurfactants produced by marine microorganisms with potential therapeutic applications and discusses future perspectives and opportunities to discover novel molecules from marine environments.

  18. Identification and Characterization of Extremophile Microorganisms with Significance to Astrobiology

    NASA Technical Reports Server (NTRS)

    Bej, Asim K.

    2003-01-01

    It is now well recognized that microorganisms thrive in extreme ecological conditions such as geothermal vents, polar region, acid and alkaline lakes, and the cold pressurized depth of the ocean floor of this planet. Morphological, physiological, biochemical and genetic adaptations to extreme environments by these extremophile microorganisms have generated immense interest amongst astrobiologists who increasingly believe in the existence of extraterrestrial life. The evidence collected by NASA's space probe Galileo suggested the presence of liquid water and volcanic activity on Mars and Jupiter's satellite Europa. Volcanic activity provides some of the heat necessary to keep the water on Europa from freezing that could provide important dissolved chemicals needed by living organisms. The possibility of the existence of hypersaline alkaline lakes and evaporites confined within closed volcanic basins and impact craters on Mars, and a layer of liquid water under the ice on Europa provide sufficient 'raison d'etre' to study microorganisms in similar extreme environments on Earth, which could provide us with a model that would help establish the existence of extraterrestrial life on other planetary bodies. The objectives of the summer research project were as follows: (1) application of molecular approaches to help establish new species of extremophile microorganisms isolated from a hypersaline alkaline lake; and (2) identification of a major cold-shock gene (cspA) homolog from a psychrotolerant microorganism, PmagG1.

  19. 40 CFR 725.12 - Identification of microorganisms for Inventory and other listing purposes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Identification of microorganisms for... MICROORGANISMS General Provisions and Applicability § 725.12 Identification of microorganisms for Inventory and other listing purposes. To identify and list microorganisms on the Inventory, both...

  20. 40 CFR 725.12 - Identification of microorganisms for Inventory and other listing purposes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Identification of microorganisms for... MICROORGANISMS General Provisions and Applicability § 725.12 Identification of microorganisms for Inventory and other listing purposes. To identify and list microorganisms on the Inventory, both...

  1. 40 CFR 725.12 - Identification of microorganisms for Inventory and other listing purposes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Identification of microorganisms for... MICROORGANISMS General Provisions and Applicability § 725.12 Identification of microorganisms for Inventory and other listing purposes. To identify and list microorganisms on the Inventory, both...

  2. 40 CFR 725.12 - Identification of microorganisms for Inventory and other listing purposes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Identification of microorganisms for... MICROORGANISMS General Provisions and Applicability § 725.12 Identification of microorganisms for Inventory and other listing purposes. To identify and list microorganisms on the Inventory, both...

  3. 9 CFR 114.5 - Micro-organisms used as seed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Micro-organisms used as seed. 114.5... BIOLOGICAL PRODUCTS § 114.5 Micro-organisms used as seed. Micro-organisms used in the preparation of... conditions. A complete record of such micro-organisms shall be kept currently correct and a list submitted...

  4. 9 CFR 114.5 - Micro-organisms used as seed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Micro-organisms used as seed. 114.5... BIOLOGICAL PRODUCTS § 114.5 Micro-organisms used as seed. Micro-organisms used in the preparation of... conditions. A complete record of such micro-organisms shall be kept currently correct and a list submitted...

  5. 9 CFR 114.5 - Micro-organisms used as seed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Micro-organisms used as seed. 114.5... BIOLOGICAL PRODUCTS § 114.5 Micro-organisms used as seed. Micro-organisms used in the preparation of... conditions. A complete record of such micro-organisms shall be kept currently correct and a list submitted...

  6. Review: Diversity of Microorganisms in Global Fermented Foods and Beverages

    PubMed Central

    Tamang, Jyoti P.; Watanabe, Koichi; Holzapfel, Wilhelm H.

    2016-01-01

    Culturalable and non-culturable microorganisms naturally ferment majority of global fermented foods and beverages. Traditional food fermentation represents an extremely valuable cultural heritage in most regions, and harbors a huge genetic potential of valuable but hitherto undiscovered strains. Holistic approaches for identification and complete profiling of both culturalable and non-culturable microorganisms in global fermented foods are of interest to food microbiologists. The application of culture-independent technique has thrown new light on the diversity of a number of hitherto unknown and non-cultural microorganisms in naturally fermented foods. Functional bacterial groups (“phylotypes”) may be reflected by their mRNA expression in a particular substrate and not by mere DNA-level detection. An attempt has been made to review the microbiology of some fermented foods and alcoholic beverages of the world. PMID:27047484

  7. The role of microorganisms in coral health, disease and evolution.

    PubMed

    Rosenberg, Eugene; Koren, Omry; Reshef, Leah; Efrony, Rotem; Zilber-Rosenberg, Ilana

    2007-05-01

    Coral microbiology is an emerging field, driven largely by a desire to understand, and ultimately prevent, the worldwide destruction of coral reefs. The mucus layer, skeleton and tissues of healthy corals all contain large populations of eukaryotic algae, bacteria and archaea. These microorganisms confer benefits to their host by various mechanisms, including photosynthesis, nitrogen fixation, the provision of nutrients and infection prevention. Conversely, in conditions of environmental stress, certain microorganisms cause coral bleaching and other diseases. Recent research indicates that corals can develop resistance to specific pathogens and adapt to higher environmental temperatures. To explain these findings the coral probiotic hypothesis proposes the occurrence of a dynamic relationship between symbiotic microorganisms and corals that selects for the coral holobiont that is best suited for the prevailing environmental conditions. Generalization of the coral probiotic hypothesis has led us to propose the hologenome theory of evolution.

  8. Multispecies Swarms of Social Microorganisms as Moving Ecosystems.

    PubMed

    Ben-Jacob, Eshel; Finkelshtein, Alin; Ariel, Gil; Ingham, Colin

    2016-04-01

    Microorganisms use collective migration to cross barriers and reach new habitats, and the ability to form motile swarms offers a competitive advantage. Traditionally, dispersal by microbial swarm propagation has been studied in monoculture. Microorganisms can facilitate other species' dispersal by forming multispecies swarms, with mutual benefits. One party (the transporter) moves a sessile partner (the cargo). This results in asymmetric associations ranging from temporary marriages of convenience to long-term fellow travellers. In the context of the 'microbial market', the parties offer very different services in exchange. We discuss bacteria transporting bacteria, eukaryotic microorganisms moving bacteria, and bacteria facilitating the spread of eukaryotes - and ask what the benefits are, the methods of study, and the consequences of multispecies, swarming logistics networks.

  9. Limitations to growth of microorganisms on Uranus, Neptune, and Titan

    NASA Technical Reports Server (NTRS)

    Margulis, L.; Halvorson, H. O.; Lewis, J.; Cameron, A. G. W.

    1977-01-01

    Reappraisal of the probabilistic policy toward planetary contamination by terrestrial microorganisms carried aboard space probes is suggested on the grounds that assignment of numerical probabilities to qualitatively unknown phenomena, as expressed in Phillips's (1974) formulation of the probability of contamination, is inappropriate. As an alternative, it is proposed that fundamental knowledge of the interacting nature of life on earth, interrelations between terrestrial organisms, and continuing effects of these organisms on earth's atmosphere and surface should guide the formulation of a sounder scientific quarantine policy. Simple conservative atmospheric models most favorable for life on Uranus and Neptune are examined. It is concluded that terrestrial microorganisms will not grow on either planet due to limitations of liquid water, atmospheric convection to lethal depths, the absence of energy sources and nutrients, the presence of ammonia and hydrogen, insufficient concentrations of biologically necessary ions, and the lack of a surface. The likelihood of terrestrial microorganism growth on Titan is found to be vanishingly small.

  10. Fluorescent antibody detection of microorganisms in terrestrial environments

    NASA Technical Reports Server (NTRS)

    Schmidt, E. L.

    1972-01-01

    The fluorescent antibody technique and its use in direct microscopic examination of the soil is discussed. Feasibility analyses were made to determine if the method could be used to simultaneously observe and recognize microorganisms in the soil. Some data indicate this may be possible. Data are also given on two related problems involving the interaction of soil microorganisms with plant roots to form symbiotic structures. One was concerned with the developmental ecology and biology of the root nodule of alder and the second was concerned with the ectotrophic mycorrhizal structure on forest trees, especially pines. In both, the fluorescent antibody detection of the microbial symbiont both as a free living form in soil, and as a root inhabiting form in the higher plant was emphasized. A third aspect of the research involved the detection of autotrophic ammonia oxidizing microorganisms in soil.

  11. Plant development in the absence of epiphytic microorganisms

    NASA Astrophysics Data System (ADS)

    Kutschera, U.; Koopmann, V.; Grotha, R.

    2002-05-01

    Microorganisms (bacteria, fungi) are common residents of the roots, stems and leaves of higher plants. In order to explore the dependency of plant development on the presence of epiphytic microorganisms, the achenes (seeds) of sunflower (Helianthus annuus L.) were sterilized and germinated under aseptic conditions. The sterility of the seedlings was determined with the agar impression method. In seedlings from non-sterile seeds (control) that were likewise raised in a germ-free environment, all plant organs investigated (stem, cotyledons and primary leaves) were contaminated with bacteria. Hypocotyl elongation was not affected by epiphytic microorganisms. However, the growth rates of the cotyledons and primary leaves were higher in sterile seedlings compared with the control. The implications of this differential inhibition of organ development by epiphytic bacteria that are transmitted via the outer surface of the seed coat are discussed. We conclude that epiphytes in the above-ground phytosphere are not necessary for the development of the sunflower seedling.

  12. Modelling of microorganisms capture on magnetic carrier particles

    NASA Astrophysics Data System (ADS)

    Rotariu, O.; Strachan, N. J. C.; Bădescu, V.

    2002-11-01

    Immunomagnetic separation (IMS) is a technique used in the detection of pathogenic microorganisms from food and environmental samples. Current IMS methods are insensitive due to the small sample sizes analysed. A stochastic model is described which estimates the time of collision between a small number of pathogenic microorganisms and superparamagnetic carrier microparticles within an aqueous suspension. The IMS system parameters which are varied in the model include: the diameter of the carrier particles, their volume concentration in suspension, the fraction of magnetic phase within the composite material of the particles and the magnetic field intensity and gradient. The data obtained will be used to help design magnetic separation systems to capture pathogenic microorganisms from large volume samples (approx. 250 ml).

  13. Workshop on Spaceflight Alterations in Host-Microorganism Interactions

    NASA Technical Reports Server (NTRS)

    Ott, C. Mark

    2010-01-01

    On June 11, 2009, a workshop that included internal and external experts was convened to determine the risk of changes in microorganisms that could alter host-microorganism interactions during a mission. The evidence is based in part on multiple flight experiments which indicate altered virulence in Salmonella typhimurium when cultured in flight. The workshop participants were tasked to determine if adequate information was available to initiate changes in NASA's current approach to infectious disease risk assessment and medical operations. The consensus of the participants is that the current evidence was not adequate to provide direction for operational changes; however, the evidence is compelling and clearly indicates that changes to microorganisms were occurring during spaceflight and further research is required.

  14. Opportunistic microorganisms in individuals with lesions of denture stomatitis.

    PubMed

    Pereira, Cristiane Aparecida; Toledo, Bruna Costa; Santos, Camila Teles; Pereira Costa, Anna Carolina Borges; Back-Brito, Graziella Nuernberg; Kaminagakura, Estela; Jorge, Antonio Olavo Cardoso

    2013-08-01

    The aim of this study was to isolate, quantify, identify, and compare opportunistic microorganisms (Candida and Staphylococcus genera and Enterobacteriaceae/Pseudomonadaceae families) from prosthesis-fitting surfaces, the hard palate, and mouth rinses of individuals wearing removable maxillary prosthesis with (50) and without (50) lesions of denture stomatitis (DS). The strains were collected and identified using phenotypic, biochemical and molecular tests. The counts of microorganisms were significantly higher in the group of individuals with DS (P < 0.05). C. albicans was the most frequently isolated yeast species in both groups, following by C. tropicalis and C. glabrata. Six isolates were identified as C. dubliniensis. S. aureus and S. epidermidis were the most frequent Staphylococcus species in both groups. Klebsiella pneumoniae was the predominant species in both groups. The association between Candida spp. and bacteria isolated in this study with DS suggests that these microorganisms may play important roles in the establishment and persistence of this disease.

  15. [Microorganisms surviving in drinking water systems and related problems].

    PubMed

    Aulicino, F A; Pastoni, F

    2004-01-01

    Drinking water in distribution systems may show abnormal values of some parameters, such as turbidity, and may support particular phenomena, such as bacterial regrowth or presence of Viable Not Culturable (VNC) bacteria. Turbidity can provide shelter for opportunistic microorganisms and pathogens. The Milwaukee outbreak (400,000 people) is one example of waterborne disease caused by the presence of pathogens (Cryptosporidium) in drinking water characterized by high and intermittent levels of turbidity. Bacterial regrowth in drinking water distribution systems may cause high increments of microorganisms such as heterotrophic bacteria, coliforms and pathogens. Microorganisms isolated from biofilm including Pseudomonas, Aeromonas, Legionella may have a significant health hazard especially in hospital areas. The presence of VNC bacteria in drinking water may represent a problem for their discussed role in infectious diseases, but also for the possibility of a considerable underestimation of true microbial concentrations in drinking waters. To study this kind of problems is necessary to apply suitable methods for drinking water analyses.

  16. Symbiotic microorganisms: untapped resources for insect pest control.

    PubMed

    Douglas, Angela E

    2007-08-01

    Symbiotic microorganisms offer one route to meet the anticipated heightened demand for novel insect pest management strategies created by growing human populations and global climate change. Two approaches have particular potential: the disruption of microbial symbionts required by insect pests, and manipulation of microorganisms with major impacts on insect traits contributing to their pest status (e.g. capacity to vector diseases, natural enemy resistance). Specific research priorities addressed in this article include identification of molecular targets against which highly specific antagonists can be designed or discovered, and management strategies to manipulate the incidence and properties of facultative microorganisms that influence insect pest traits. Collaboration with practitioners in pest management will ensure that the research agenda is married to agricultural and public health needs.

  17. Heavy metals and adsorbents effects on activated sludge microorganisms.

    PubMed

    Ong, S A; Lim, P E; Seng, C E

    2004-01-01

    The sorption of Cu(II) and Cd(II) from synthetic solution by powdered activated carbon (PAC), biomass, rice husk (RH) and activated rice husk (ARH) were investigate under batch conditions. After activated by concentrated nitric acid for 15 hours at 60-65 degrees C, the adsorption capacity for RH was increased. The adsorbents arranged in the increasing order of adsorption capacities to the Langmuir Q degree parameter were biomass > PAC > ARH > RH. The addition of adsorbents in base mix solution had increased the specific oxygen uptake rate (SOUR) activated sludge microorganisms with and without the presence of metals. The increased of SOUR were due to the ability of PAC and RH in reducing the inhibitory effect of metals on microorganisms and provide a reaction site between activated sludge microorganisms and substrates.

  18. Potential role of microorganisms in the pathogenesis of rosacea.

    PubMed

    Holmes, Anna D

    2013-12-01

    Rosacea is a skin condition of abnormal inflammation and vascular dysfunction. The active contribution of a microbial agent in the development or progression of rosacea continues to be debated. Research supports the presence of commensal Demodex folliculorum mites at increased density in the skin and associates Helicobacter pylori infection of the gut with rosacea. Fewer studies implicate Staphylococcus epidermidis, Chlamydophila pneumoniae, and the Demodex-associated bacteria Bacillus oleronius. No research, however, provides a mechanism by which colonization by a microorganism translates to manifestation of the condition. Prevailing and emerging principles in the biology of the microbiome and the pathophysiology of rosacea may help to reconcile these lingering questions. Here the microorganisms implicated in rosacea are reviewed and the reaction of the microbiome to inflammation and to changes in microenvironments and macroenvironments are discussed to explain potential roles for microorganisms in rosacea pathophysiology.

  19. A new ultrasound based method for rapid microorganism detection

    NASA Astrophysics Data System (ADS)

    Shukla, Shiva Kant; Segura, Luis Elvira; Sánchez, Carlos José Sierra; López, Pablo Resa

    2012-05-01

    A new method for rapid detection of catalase positive microorganisms by using an ultrasonic measuring method is proposed in this work. The developed technique is based on the detection of oxygen bubbles produced by the hydrolysis of hydrogen peroxide induced by the enzyme catalase which is present in many microorganisms. The bubbles are trapped in a media based on agar gel which was especially developed for microbiological evaluation. It is found that microorganism concentrations of the order of 105 c.f.u./ml can be detected by using this method. The results obtained show up that the proposed method is competitive with other modern commercial methods like luminescence by ATP system. The method can also be used for characterization of enzyme activity.

  20. Systems biology for understanding and engineering of heterotrophic oleaginous microorganisms.

    PubMed

    Park, Beom Gi; Kim, Minsuk; Kim, Joonwon; Yoo, Heewang; Kim, Byung-Gee

    2017-01-01

    Heterotrophic oleaginous microorganisms continue to draw interest as they can accumulate a large amount of lipids which is a promising feedstock for the production of biofuels and oleochemicals. Nutrient limitation, especially nitrogen limitation, is known to effectively trigger the lipid production in these microorganisms. For the aim of developing improved strains, the mechanisms behind the lipid production have been studied for a long time. Nowadays, system-level understanding of their metabolism and associated metabolic switches is attainable with modern systems biology tools. This work reviews the systems biology studies, based on (i) top-down, large-scale 'omics' tools, and (ii) bottom-up, mathematical modeling methods, on the heterotrophic oleaginous microorganisms with an emphasis on further application to metabolic engineering.

  1. Microorganisms From a Depth of 1350 m in Hawaii

    NASA Astrophysics Data System (ADS)

    Fisk, M. R.; Storrie-Lombardi, M. C.; Douglas, S.; Popa, R.

    2001-12-01

    The Hawaii Scientific Drilling Program recovered cores of igneous rock from the surface to a depth of 3109 m near Hilo, Hawaii. After examining most lithologic units from this site with a petrographic microscope, we concentrated on a single unit of hyaloclastite at 1335 to 1415 m below sea level. For this study we used deep ultraviolet laser-induced native fluorescence imaging, ultraviolet Raman spectroscopy, scanning environmental electron microscopy, DNA-staining, electron microprobe chemical analysis, and microscopic petrographic observation. Each technique revealed a signature consistent with biological activity associated with alteration of glass to clay. Vesicles were surrounded by dark zones of alteration from which smooth, rounded channels extended into the glass similar to those attributed to microorganisms in deep sea basalt glass. Enrichments of phosphorus and carbon were associated with these same regions of the basalt. The rims of vesicles produced laser-induced fluorescence and Raman spectra that indicate the presence of amino acids and nucleic acids. These same rims were examined with an environmental electron microscope and were found to contain microorganisms. This result was confirmed with DNA staining of vesicle rims. These results taken together confirm the presence of microorganisms at the boundary between primary volcanic glass and secondary clays. This boundary is the site of chemical transformations that can provide metabolic energy for microorganisms. The glass can also be a source of nutrients such as phosphorus, however, at this time the physiology of the microorganisms is not known. Although we examined only one lithologic unit in detail, petrographic examination of other samples suggests that microorganisms are, or were, present in over 700 m of the hole.

  2. Biological warfare: Microorganisms as drivers of host-parasite interactions.

    PubMed

    Dheilly, Nolwenn M; Poulin, Robert; Thomas, Frédéric

    2015-08-01

    Understanding parasite strategies for evasion, manipulation or exploitation of hosts is crucial for many fields, from ecology to medical sciences. Generally, research has focused on either the host response to parasitic infection, or the parasite virulence mechanisms. More recently, integrated studies of host-parasite interactions have allowed significant advances in theoretical and applied biology. However, these studies still provide a simplistic view of these as mere two-player interactions. Host and parasite are associated with a myriad of microorganisms that could benefit from the improved fitness of their partner. Illustrations of such complex multi-player interactions have emerged recently from studies performed in various taxa. In this conceptual article, we propose how these associated microorganisms may participate in the phenotypic alterations induced by parasites and hence in host-parasite interactions, from an ecological and evolutionary perspective. Host- and parasite-associated microorganisms may participate in the host-parasite interaction by interacting directly or indirectly with the other partner. As a result, parasites may develop (i) the disruptive strategy in which the parasite alters the host microbiota to its advantage, and (ii) the biological weapon strategy where the parasite-associated microorganism contributes to or modulates the parasite's virulence. Some phenotypic alterations induced by parasite may also arise from conflicts of interests between the host or parasite and its associated microorganism. For each situation, we review the literature and propose new directions for future research. Specifically, investigating the role of host- and parasite-associated microorganisms in host-parasite interactions at the individual, local and regional level will lead to a holistic understanding of how the co-evolution of the different partners influences how the other ones respond, both ecologically and evolutionary. The conceptual framework we

  3. Identification of beer spoilage microorganisms using the MALDI Biotyper platform.

    PubMed

    Turvey, Michelle Elizabeth; Weiland, Florian; Meneses, Jon; Sterenberg, Nick; Hoffmann, Peter

    2016-03-01

    Beer spoilage microorganisms present a major risk for the brewing industry and can lead to cost-intensive recall of contaminated products and damage to brand reputation. The applicability of molecular profiling using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) in combination with Biotyper software was investigated for the identification of beer spoilage microorganisms from routine brewery quality control samples. Reference mass spectrum profiles for three of the most common bacterial beer spoilage microorganisms (Lactobacillus lindneri, Lactobacillus brevis and Pediococcus damnosus), four commercially available brewing yeast strains (top- and bottom-fermenting) and Dekkera/Brettanomyces bruxellensis wild yeast were established, incorporated into the Biotyper reference library and validated by successful identification after inoculation into beer. Each bacterial species could be accurately identified and distinguished from one another and from over 5600 other microorganisms present in the Biotyper database. In addition, wild yeast contaminations were rapidly detected and distinguished from top- and bottom-fermenting brewing strains. The applicability and integration of mass spectrometry profiling using the Biotyper platform into existing brewery quality assurance practices within industry were assessed by analysing routine microbiology control samples from a local brewery, where contaminating microorganisms could be reliably identified. Brewery-isolated microorganisms not present in the Biotyper database were further analysed for identification using LC-MS/MS methods. This renders the Biotyper platform a promising candidate for biological quality control testing within the brewing industry as a more rapid, high-throughput and cost-effective technology that can be tailored for the detection of brewery-specific spoilage organisms from the local environment.

  4. Microbial biosensors: engineered microorganisms as the sensing machinery.

    PubMed

    Park, Miso; Tsai, Shen-Long; Chen, Wilfred

    2013-05-06

    Whole-cell biosensors are a good alternative to enzyme-based biosensors since they offer the benefits of low cost and improved stability. In recent years, live cells have been employed as biosensors for a wide range of targets. In this review, we will focus on the use of microorganisms that are genetically modified with the desirable outputs in order to improve the biosensor performance. Different methodologies based on genetic/protein engineering and synthetic biology to construct microorganisms with the required signal outputs, sensitivity, and selectivity will be discussed.

  5. Trapping of Swimming Microorganisms at Lower Surfaces by Increasing Buoyancy

    NASA Astrophysics Data System (ADS)

    Jung, Ilyong; Guevorkian, Karine; Valles, James M.

    2014-11-01

    Models suggest that mechanical interactions alone can trap swimming microorganisms at surfaces. Testing them requires a method for varying the mechanical interactions. We tuned contact forces between Paramecia and surfaces in situ by varying their buoyancy with nonuniform magnetic fields. Remarkably, increasing their buoyancy can lead to ˜100 % trapping at lower surfaces. A model of Paramecia in surface contact passively responding to external torques quantitatively accounts for the data implying that interactions with a planar surface do not engage their mechanosensing network and illuminating how their trapping differs from other smaller microorganisms.

  6. Microbial Biosensors: Engineered Microorganisms as the Sensing Machinery

    PubMed Central

    Park, Miso; Tsai, Shen-Long; Chen, Wilfred

    2013-01-01

    Whole-cell biosensors are a good alternative to enzyme-based biosensors since they offer the benefits of low cost and improved stability. In recent years, live cells have been employed as biosensors for a wide range of targets. In this review, we will focus on the use of microorganisms that are genetically modified with the desirable outputs in order to improve the biosensor performance. Different methodologies based on genetic/protein engineering and synthetic biology to construct microorganisms with the required signal outputs, sensitivity, and selectivity will be discussed. PMID:23648649

  7. Gut Microorganisms Found Necessary for Successful Cancer Therapy | Poster

    Cancer.gov

    By Nancy Parrish, Staff Writer Humans play host to trillions of microorganisms that help our bodies perform basic functions, like digestion, growth, and fighting disease. In fact, bacterial cells outnumber the human cells in our bodies by 10 to 1.1 The tens of trillions of microorganisms thriving in our intestines are known as gut microbiota, and those that are not harmful to us are referred to as commensal microbiota. In a recent paper in Science, NCI scientists described their discovery that, in mice, the presence of commensal microbiota is needed for successful response to cancer therapy.

  8. [Epidemiology of the infection by resistant Gram-positive microorganisms].

    PubMed

    Cercenado, E

    2016-09-01

    Resistance among Gram-positive microorganisms to classical and new antimicrobials is a therapeutic threat. In Spain, methicillin resistance among Staphylococcus aureus (25-30%) and coagulase-negative staphylococci (50-60%) seems to have stabilized in the last decade. Among enterococci, vancomycin resistance is less than 5%. Both linezolid and daptomycin, in general, show good activity against these microorganisms. However, the resistance rates of Staphylococcus epidermidis to linezolid (20.9%), and of Enterococcus faecium to daptomycin (10.5%) in isolates from intensive care units are a worrying.

  9. Biosynthesis of anti-HCV compounds using thermophilic microorganisms.

    PubMed

    Rivero, Cintia W; De Benedetti, Eliana C; Sambeth, Jorge E; Lozano, Mario E; Trelles, Jorge A

    2012-10-01

    This work describes the application of thermophilic microorganisms for obtaining 6-halogenated purine nucleosides. Biosynthesis of 6-chloropurine-2'-deoxyriboside and 6-chloropurine riboside was achieved by Geobacillus stearothermophilus CECT 43 with a conversion of 90% and 68%, respectively. Furthermore, the selected microorganism was satisfactorily stabilized by immobilization in an agarose matrix. This biocatalyst can be reused at least 70 times without significant loss of activity, obtaining 379mg/L of 6-chloropurine-2'-deoxyriboside. The obtained compounds can be used as antiviral agents.

  10. Identifying microorganisms responsible for ecologically significant biogeochemical processes.

    PubMed

    Madsen, Eugene L

    2005-05-01

    Throughout evolutionary time, and each day in every habitat throughout the globe, microorganisms have been responsible for maintaining the biosphere. Despite the crucial part that they play in the cycling of nutrients in habitats such as soils, sediments and waters, only rarely have the microorganisms actually responsible for key processes been identified. Obstacles that have traditionally impeded fundamental microbial ecology inquiries are now yielding to technical advancements that have important parallels in medical microbiology. The pace of new discoveries that document ecological processes and their causative agents will no doubt accelerate in the near future, and might assist in ecosystem management.

  11. Trapping of swimming microorganisms at lower surfaces by increasing buoyancy.

    PubMed

    Jung, Ilyong; Guevorkian, Karine; Valles, James M

    2014-11-21

    Models suggest that mechanical interactions alone can trap swimming microorganisms at surfaces. Testing them requires a method for varying the mechanical interactions. We tuned contact forces between Paramecia and surfaces in situ by varying their buoyancy with nonuniform magnetic fields. Remarkably, increasing their buoyancy can lead to ∼100% trapping at lower surfaces. A model of Paramecia in surface contact passively responding to external torques quantitatively accounts for the data implying that interactions with a planar surface do not engage their mechanosensing network and illuminating how their trapping differs from other smaller microorganisms.

  12. Plasma inactivation of microorganisms on sprout seeds in a dielectric barrier discharge.

    PubMed

    Butscher, Denis; Van Loon, Hanne; Waskow, Alexandra; Rudolf von Rohr, Philipp; Schuppler, Markus

    2016-12-05

    Fresh produce is frequently contaminated by microorganisms, which may lead to spoilage or even pose a threat to human health. In particular sprouts are considered to be among the most risky foods sold at retail since they are grown in an environment practically ideal for growth of bacteria and usually consumed raw. Because heat treatment has a detrimental effect on the germination abilities of sprout seeds, alternative treatment technologies need to be developed for microbial inactivation purposes. In this study, non-thermal plasma decontamination of sprout seeds is evaluated as a promising option to enhance food safety while maintaining the seed germination capabilities. In detail, investigations focus on understanding the efficiency of non-thermal plasma inactivation of microorganisms as influenced by the type of microbial contamination, substrate surface properties and moisture content, as well as variations in the power input to the plasma device. To evaluate the impact of these parameters, we studied the reduction of native microbiota or artificially applied E. coli on alfalfa, onion, radish and cress seeds exposed to non-thermal plasma in an atmospheric pressure pulsed dielectric barrier discharge streamed with argon. Plasma treatment resulted in a maximum reduction of 3.4 logarithmic units for E. coli on cress seeds. A major challenge in plasma decontamination of granular food products turned out to be the complex surface topology, where the rough surface with cracks and crevices can shield microorganisms from plasma-generated reactive species, thus reducing the treatment efficiency. However, improvement of the inactivation efficiency was possible by optimizing substrate characteristics such as the moisture level and by tuning the power supply settings (voltage, frequency) to increase the production of reactive species. While the germination ability of alfalfa seeds was considerably decreased by harsh plasma treatment, enhanced germination was observed under

  13. Extremely thermophilic microorganisms as metabolic engineering platforms for production of fuels and industrial chemicals.

    PubMed

    Zeldes, Benjamin M; Keller, Matthew W; Loder, Andrew J; Straub, Christopher T; Adams, Michael W W; Kelly, Robert M

    2015-01-01

    Enzymes from extremely thermophilic microorganisms have been of technological interest for some time because of their ability to catalyze reactions of industrial significance at elevated temperatures. Thermophilic enzymes are now routinely produced in recombinant mesophilic hosts for use as discrete biocatalysts. Genome and metagenome sequence data for extreme thermophiles provide useful information for putative biocatalysts for a wide range of biotransformations, albeit involving at most a few enzymatic steps. However, in the past several years, unprecedented progress has been made in establishing molecular genetics tools for extreme thermophiles to the point that the use of these microorganisms as metabolic engineering platforms has become possible. While in its early days, complex metabolic pathways have been altered or engineered into recombinant extreme thermophiles, such that the production of fuels and chemicals at elevated temperatures has become possible. Not only does this expand the thermal range for industrial biotechnology, it also potentially provides biodiverse options for specific biotransformations unique to these microorganisms. The list of extreme thermophiles growing optimally between 70 and 100°C with genetic toolkits currently available includes archaea and bacteria, aerobes and anaerobes, coming from genera such as Caldicellulosiruptor, Sulfolobus, Thermotoga, Thermococcus, and Pyrococcus. These organisms exhibit unusual and potentially useful native metabolic capabilities, including cellulose degradation, metal solubilization, and RuBisCO-free carbon fixation. Those looking to design a thermal bioprocess now have a host of potential candidates to choose from, each with its own advantages and challenges that will influence its appropriateness for specific applications. Here, the issues and opportunities for extremely thermophilic metabolic engineering platforms are considered with an eye toward potential technological advantages for high

  14. Role of microorganisms for cycling of atmospheric constituents, emphasizing the greenhouse gas methane (Invited)

    NASA Astrophysics Data System (ADS)

    Conrad, R.

    2013-12-01

    Microorganisms have contributed significantly to the formation of the atmosphere and the habitability of Earth. Microbial methanogenesis probably helped overcoming the faint sun problem on young Earth. Later on, cyanobacterial photosynthesis produced oxygen and thus restricted the life zone of methanogenic microbial communities, which nowadays contribute only about 1% to total carbon cycle. Nevertheless, methanogenesis still dominates the budget of atmospheric methane and contributes significantly to the greenhouse effect. There are numerous habitats, which exchange methane with the atmosphere, and even more in which methane is intensively cycled albeit little emitted. Methane can be a byproduct of chemical reactions in plant leaves, or of aerobic methyl phosphonate consumption in ocean water. Most commonly, however, methane is a stoichiometric catabolic product in the degradation of organic matter by anaerobic microorganisms. The degradation is achieved by a complex microbial community consisting of various species of hydrolytic and fermentative Bacteria that produce hydrogen, carbon dioxide and acetate as major end products, and of methanogenic Archaea that eventually convert these compounds to methane and carbon dioxide. The composition of such methanogenic microbial communities, the rates and paths of methane formation, and the isotopic composition of the produced methane all exhibit quite some variability across the different habitats in which methane is produced from organic matter decomposition, such as flooded soils, lake sediments, peatlands, animal gut systems. The structure of the microbial communities often strongly affects their function. It is a challenging task to understand the environmental and biochemical basis of the interactions of abiotic factors and microorganisms shaping the structure and function of the microbial communities in the different methanogenic habitats.

  15. Extremely thermophilic microorganisms as metabolic engineering platforms for production of fuels and industrial chemicals

    PubMed Central

    Zeldes, Benjamin M.; Keller, Matthew W.; Loder, Andrew J.; Straub, Christopher T.; Adams, Michael W. W.; Kelly, Robert M.

    2015-01-01

    Enzymes from extremely thermophilic microorganisms have been of technological interest for some time because of their ability to catalyze reactions of industrial significance at elevated temperatures. Thermophilic enzymes are now routinely produced in recombinant mesophilic hosts for use as discrete biocatalysts. Genome and metagenome sequence data for extreme thermophiles provide useful information for putative biocatalysts for a wide range of biotransformations, albeit involving at most a few enzymatic steps. However, in the past several years, unprecedented progress has been made in establishing molecular genetics tools for extreme thermophiles to the point that the use of these microorganisms as metabolic engineering platforms has become possible. While in its early days, complex metabolic pathways have been altered or engineered into recombinant extreme thermophiles, such that the production of fuels and chemicals at elevated temperatures has become possible. Not only does this expand the thermal range for industrial biotechnology, it also potentially provides biodiverse options for specific biotransformations unique to these microorganisms. The list of extreme thermophiles growing optimally between 70 and 100°C with genetic toolkits currently available includes archaea and bacteria, aerobes and anaerobes, coming from genera such as Caldicellulosiruptor, Sulfolobus, Thermotoga, Thermococcus, and Pyrococcus. These organisms exhibit unusual and potentially useful native metabolic capabilities, including cellulose degradation, metal solubilization, and RuBisCO-free carbon fixation. Those looking to design a thermal bioprocess now have a host of potential candidates to choose from, each with its own advantages and challenges that will influence its appropriateness for specific applications. Here, the issues and opportunities for extremely thermophilic metabolic engineering platforms are considered with an eye toward potential technological advantages for high

  16. 21 CFR 866.2660 - Microorganism differentiation and identification device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Microorganism differentiation and identification device. 866.2660 Section 866.2660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology...

  17. 21 CFR 866.2660 - Microorganism differentiation and identification device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microorganism differentiation and identification device. 866.2660 Section 866.2660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology...

  18. 21 CFR 866.2660 - Microorganism differentiation and identification device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Microorganism differentiation and identification device. 866.2660 Section 866.2660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology...

  19. 21 CFR 866.2660 - Microorganism differentiation and identification device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Microorganism differentiation and identification device. 866.2660 Section 866.2660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology...

  20. 21 CFR 866.2660 - Microorganism differentiation and identification device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Microorganism differentiation and identification device. 866.2660 Section 866.2660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology...

  1. Alum affects ammonia-producing microorganisms in poultry litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scientists at the USDA-ARS in Bowling Green, KY and in Fayetteville, AR are working to uncover the microbiology of ammonia production in poultry litter. Poultry litter is a valuable nutrient source for plants and microorganisms that contains high levels of protein, nitrogen, and other minerals. Howe...

  2. Comment on "Early Archaean microorganisms preferred elemental sulfur, not sulfate".

    PubMed

    Bao, Huiming; Sun, Tao; Kohl, Issaku; Peng, Yongbo

    2008-03-07

    Philippot et al. (Reports, 14 September 2007, p. 1534) interpreted multiple-sulfur isotopic compositions of approximately 3.5-billion-year-old marine sulfide deposits as evidence that early Archaean microorganisms were not sulfate reducers but instead metabolized elemental sulfur. However, their data can be better explained by a scenario involving poor mixing of photochemical and surface sulfide sources.

  3. Advancing oleaginous microorganisms to produce lipid via metabolic engineering technology.

    PubMed

    Liang, Ming-Hua; Jiang, Jian-Guo

    2013-10-01

    With the depletion of global petroleum and its increasing price, biodiesel has been becoming one of the most promising biofuels for global fuels market. Researchers exploit oleaginous microorganisms for biodiesel production due to their short life cycle, less labor required, less affection by venue, and easier to scale up. Many oleaginous microorganisms can accumulate lipids, especially triacylglycerols (TAGs), which are the main materials for biodiesel production. This review is covering the related researches on different oleaginous microorganisms, such as yeast, mold, bacteria and microalgae, which might become the potential oil feedstocks for biodiesel production in the future, showing that biodiesel from oleaginous microorganisms has a great prospect in the development of biomass energy. Microbial oils biosynthesis process includes fatty acid synthesis approach and TAG synthesis approach. In addition, the strategies to increase lipids accumulation via metabolic engineering technology, involving the enhancement of fatty acid synthesis approach, the enhancement of TAG synthesis approach, the regulation of related TAG biosynthesis bypass approaches, the blocking of competing pathways and the multi-gene approach, are discussed in detail. It is suggested that DGAT and ME are the most promising targets for gene transformation, and reducing PEPC activity is observed to be beneficial for lipid production.

  4. Alkalizing Reactions Streamline Cellular Metabolism in Acidogenic Microorganisms

    PubMed Central

    Arioli, Stefania; Ragg, Enzio; Scaglioni, Leonardo; Fessas, Dimitrios; Signorelli, Marco; Karp, Matti; Daffonchio, Daniele; De Noni, Ivano; Mulas, Laura; Oggioni, Marco; Guglielmetti, Simone; Mora, Diego

    2010-01-01

    An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms. PMID:21152088

  5. [Informatics in food microbiology: applications for the identification of microorganisms].

    PubMed

    Prieto Maradona, M

    1993-02-01

    Recent progress in analytical procedures (chemotaxonomy, molecular biology) and its contribution to the development of microbial Systematics and Identification have been examined. The benefit that these techniques have gained from the technological progression experienced by computer hardware and software (artificial intelligence and numerical taxonomy) and the improvement in tools for the study of characteristics and interrelationships between microorganism are also reported.

  6. Is arsenic biotransformation a detoxification mechanism for microorganisms?

    PubMed

    Rahman, M Azizur; Hassler, Christel

    2014-01-01

    Arsenic (As) is extremely toxic to living organisms at high concentration. In aquatic systems, As exists in different chemical forms. The two major inorganic As (iAs) species are As(V), which is thermodynamically stable in oxic waters, and As(III), which is predominant in anoxic conditions. Photosynthetic microorganisms (e.g., phytoplankton and cyanobacteria) take up As(V), biotransform it to As(III), then biomethylate it to methylarsenic (MetAs) forms. Although As(III) is more toxic than As(V), As(III) is much more easily excreted from the cells than As(V). Therefore, majority of researchers consider the reduction of As(V) to As(III) as a detoxification process. The biomethylation process results in the conversion of toxic iAs to the less toxic pentavalent MetAs forms (monomethylarsonate; MMA(V), dimethylarsonate; DMA(V), and trimethylarsenic oxide; TMAO(V)) and trimethylarsine (TMAO(III)). However, biomethylation by microorganisms also produces monomethylarsenite (MMA(III)) and dimethylarsenite (DMA(III)), which are more toxic than iAs, as a result of biomethylation by the microorganisms, demonstrates the need to reconsider to what extent As biomethylation contributes to a detoxification process. In this review, we focused on the discussion of whether the biotransformation of As species in microorganisms is really a detoxification process with recent data.

  7. Fossil Microorganisms in Archaean deposits of Northern Karelia

    NASA Technical Reports Server (NTRS)

    Astafieva, M. M.; Hoover, R. B.; Rozanov, A. Y.; Vrevskiy, A. B.

    2005-01-01

    Newly found biomorphic microstructures from the Upper Archaean (lopian) rocks from Northern Karelia are described. The presence of various microorganisms of bacterial nature and even cyanobacteria (and possibly eukaryotic forms) is suggested. The necessity of employing methods of electron microscopy, as well as traditional methods, while studying the very early manifestations of life in Archaean and Early Proterozoic is noted.

  8. Causes and implications of colloid and microorganism retention hysteresis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were designed to better understand the causes and implications of colloid and microorganism retention hysteresis with transients in solution ionic strength (IS). Saturated packed column experiments were conducted using two sizes of carboxyl modified latex (CML) microspheres (0.1 and 1.1...

  9. Children's Anthropomorphic and Anthropocentric Ideas about Micro-Organisms

    ERIC Educational Resources Information Center

    Byrne, Jenny; Grace, Marcus; Hanley, Pam

    2009-01-01

    Different views exist about whether anthropomorphic ideas assist or hinder learning in biology. This paper discusses the anthropomorphic and anthropocentric ideas children have about micro-organisms, and whether they affect their understanding. The research was carried out in primary and secondary schools in the South of England and involved 414…

  10. A spectrophotometric screening method for avermectin oxidizing microorganisms.

    PubMed

    Wang, Yuan-Shan; Hu, Qi-Wei; Zheng, Xing-Chang; Zhang, Jian-Fen; Zheng, Yu-Guo

    2017-04-01

    A spectrophotometric screening method for avermectin oxidizing microbes by determination of 4″-oxo-avermectin was established based on the reaction between 4″-oxo-avermectin and 2,4-dinitrophenylhydrazine. Combined with a gradient HPLC assay, microorganisms capable of regioselectively oxidizing avermectin to 4″-oxo-avermectin were successfully obtained by this method.

  11. Microorganisms as Analytical Indicators. Experimental Methods and Techniques,

    DTIC Science & Technology

    1980-01-01

    analytic indicators: gram- negative and gram-positive sporiferous and nonsporiferous bacteria, yeasts, mycelial fungi, and actinomycetes (Refs. 4, 6-8...growing species of microorganisms, the cultivation period is appropriately increased. This factor is less important for actinomycetes , fungi and sporiferous

  12. RIVERBANK FILTRATION: FATE OF DBP PRECURSORS AND SELECTED MICROORGANISMS

    EPA Science Inventory

    The fate of disinfection by-product (DBP) precursors and selected microorganisms during riverbank filtration (RBF) was monitored at three different mid-Western drinking water utilities. At all three sites, filtration (RBF) was monitored at three different mid-Western drinking wa...

  13. DETECTION AND ENUMERATION OF PATHOGENS AND INDICATOR MICROORGANISMS

    EPA Science Inventory

    Pathogenic microorganisms are routinely discharged to collection systems throughout the world along with a myriad of commensal organisms, organic and inorganic wastes. It is not surprising then that the density of any given pathogen is relatively small in relationship to the popu...

  14. Dispersion of flagellated swimming microorganisms in planar Poiseuille flow

    NASA Astrophysics Data System (ADS)

    Chilukuri, Sandeep; Collins, Cynthia H.; Underhill, Patrick T.

    2015-03-01

    The presence of an external fluid flow significantly impacts the properties of swimming microorganisms between two surfaces. By performing computer simulations of dilute populations of flagellated swimming microorganisms, we calculate the dispersivity of the microorganisms at different flow rates by tracking each individual organism in the direction of the flow. Our results show how the dispersion of swimming microorganisms is different from passive particles. For low flow rates, the dispersivity is higher than that of non-motile organisms because of their swimming motion. As the flow rate increases, the dispersivity drops, reaching a minimum before increasing at high flow rates. The minimum occurs approximately when the swimming speed of the organism equals the mean velocity of the external flow. A scaling analysis is used to qualitatively capture the dispersion at both low and high flow rates. Closed-form expressions for the dispersivity were derived at low and high flow rates using an analytical theory. This analysis showed that at low flow rates, the alignment of the organisms by the flow is responsible for the reduction of the dispersion in comparison to the dispersion without any external flow. At high flow rates, the distribution and dynamics across the channel produce a dispersivity that is lower than that of passive particles.

  15. Effects of temperature on biological activity of permafrost microorganisms.

    PubMed

    Kalyonova, L F; Novikova, M A; Subbotin, A M; Bazhin, A S

    2015-04-01

    The number and viability of microorganism specimens Bacillus spp. isolated from permafrost soil remained unchanged after incubation at temperatures of -16-37°C. Experiments on F1 CBA/Black-6 mice showed that incubation of bacteria at -5°C for 72 h promotes a decrease in their toxicity and an increase in their immunostimulating effect.

  16. Fossil Microorganisms and Formation of Early Precambrian Weathering Profiles

    NASA Technical Reports Server (NTRS)

    Rozanov, A. Yu; Astafieva, M. M.; Vrevsky, A. B.; Alfimova, N. A.; Matrenichev, V. A.; Hoover, R. B.

    2009-01-01

    Weathering crusts are the only reliable evidences of the existence of continental conditions. Often they are the only source of information about exogenous processes and subsequently about conditions under which the development of the biosphere occurred. A complex of diverse fossil microorganisms was discovered as a result of Scanning Electron Microscope investigations. The chemical composition of the discovered fossils is identical to that of the host rocks and is represented by Si, Al, Fe, Ca and Mg. Probably, the microorganisms fixed in rocks played the role of catalyst. The decomposition of minerals comprising the rocks and their transformation into clayey (argillaceous) minerals, most likely occurred under the influence of microorganisms. And may be unique weathering crusts of Early Precambrian were formed due to interaction between specific composition of microorganism assemblage and conditions of hypergene transformations. So it is possible to speak about colonization of land by microbes already at that time and about existence of single raw from weathering crusts (Primitive soils) to real soils.

  17. Degradation of hazardous organic wastes by microorganisms. Preliminary report

    SciTech Connect

    Kenis, P.

    1988-05-01

    This report addresses the microbiological detoxification of hazardous organic compounds before and after they have contaminated soil, ground water, and other areas. The in-situ degradation of toxic organic compounds is often the most cost-effective cleanup approach. Companies that use or provide microorganisms and other products and services for hazardous organic waste detoxification are listed in the appendices of this report.

  18. [Advances in researches of molluscicidal microorganisms against Oncomelania hupensis].

    PubMed

    Cheng, Wan-ting; Zhou, Yi-biao; Pan, Xiang; Song, Xiu-xia; Jiang, Qing-wu

    2016-02-01

    The elimination of Oncomelania hupensis snails is important to schistosomiasis control. Recently, the application of molluscicidal organisms is considered as a safe and efficient method for snail elimination. In order to provide scientific evidences for effective control of O. hupensis and schistosomiasis, this paper summarizes the researches of molluscicidal microorganisms against O. hupensis.

  19. Production of gaba (γ - Aminobutyric acid) by microorganisms: a review.

    PubMed

    Dhakal, Radhika; Bajpai, Vivek K; Baek, Kwang-Hyun

    2012-10-01

    GABA (γ-aminobutyric acid) is a four carbon non-protein amino acid that is widely distributed in plants, animals and microorganisms. As a metabolic product of plants and microorganisms produced by the decarboxylation of glutamic acid, GABA functions as an inhibitory neurotransmitter in the brain that directly affects the personality and the stress management. A wide range of traditional foods produced by microbial fermentation contain GABA, in which GABA is safe and eco-friendly, and also has the possibility of providing new health-benefited products enriched with GABA. Synthesis of GABA is catalyzed by glutamate decarboxylase, therefore, the optimal fermentation condition is mainly based on the biochemical properties of the enzyme. Major GABA producing microorganisms are lactic acid bacteria (LAB), which make food spoilage pathogens unable to grow and act as probiotics in the gastrointestinal tract. The major factors affecting the production of GABA by microbial fermentation are temperature, pH, fermentation time and different media additives, therefore, these factors are summarized to provide the most up-dated information for effective GABA synthesis. There has been a huge accumulation of knowledge on GABA application for human health accompanying with a demand on natural GABA supply. Only the GABA production by microorganisms can fulfill the demand with GABA-enriched health beneficial foods.

  20. The metabolism and biotechnological application of betaine in microorganism.

    PubMed

    Zou, Huibin; Chen, Ningning; Shi, Mengxun; Xian, Mo; Song, Yimin; Liu, Junhong

    2016-05-01

    Glycine betaine (betaine) is widely distributed in nature and can be found in many microorganisms, including bacteria, archaea, and fungi. Due to its particular functions, many microorganisms utilize betaine as a functional chemical and have evolved different metabolic pathways for the biosynthesis and catabolism of betaine. As in animals and plants, the principle role of betaine is to protect microbial cells against drought, osmotic stress, and temperature stress. In addition, the role of betaine in methyl group metabolism has been observed in a variety of microorganisms. Recent studies have shown that betaine supplementation can improve the performance of microbial strains used for the fermentation of lactate, ethanol, lysine, pyruvate, and vitamin B12, during which betaine can act as stress protectant or methyl donor for the biosynthesis of structurally complex compounds. In this review, we summarize the transport, synthesis, catabolism, and functions of betaine in microorganisms and discuss potential engineering strategies that employ betaine as a methyl donor for the biosynthesis of complex secondary metabolites such as a variety of vitamins, coenzymes, and antibiotics. In conclusion, the biocompatibility, C/N ratio, abundance, and comprehensive metabolic information of betaine collectively indicate that this molecule has great potential for broad applications in microbial biotechnology.

  1. Risk of Adverse Health Effects Due to Host-Microorganism Interactions

    NASA Technical Reports Server (NTRS)

    Ott, C. Mark; Oubre, Cherie; Castro, Sarah; Mehta, Satish; Pierson, Duane

    2015-01-01

    While preventive measures limit the presence of many medically significant microorganisms during spaceflight missions, microbial infection of crewmembers cannot be completely prevented. Spaceflight experiments over the past 50 years have demonstrated a unique microbial response to spaceflight culture, although the mechanisms behind those responses and their operational relevance were unclear. In 2007, the operational importance of these microbial responses was emphasized as the results of an experiment aboard STS-115 demonstrated that the enteric pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) increased in virulence in a murine model of infection. The experiment was reproduced in 2008 aboard STS-123 confirming this finding. In response to these findings, the Institute of Medicine of the National Academies recommended that NASA investigate this risk and its potential impact on the health of the crew during spaceflight. NASA assigned this risk to the Human Research Program. To better understand this risk, evidence has been collected and reported from both spaceflight analog systems and actual spaceflight. Although the performance of virulence studies during spaceflight are challenging and often impractical, additional information has been and continues to be collected to better understand the risk to crew health. Still, the uncertainty concerning the extent and severity of these alterations in host-microorganism interactions is very large and requires more investigation.

  2. Effect of microorganism on Greenland ice sheet surface temperature change

    NASA Astrophysics Data System (ADS)

    Shimada, R.; Takeuchi, N.; Aoki, T.

    2012-12-01

    Greenland ice sheet holds approximately 10% of the fresh water on earth. If it melts all, sea level rises about 7.2meter. It is reported that mass of Greenland ice sheet is decreasing with temperature rising of climate change. Melting of the coastal area is particularly noticeable. It is established that 4 to 23% of the sea level rising from 1993 to 2005 is caused by the melting of Greenland ice sheet. In 2010, amount of melting per year became the largest than the past. However many climate models aren't able to simulate the recent melting of snow and ice in the Arctic including Greenland. One of the possible causes is albedo reduction of snow and ice surface by light absorbing snow impurities such as black carbon and dust and by glacial microorganisms. But there are few researches for effect of glacial microorganism in wide area. So it is important to clarify the impact of glacial microorganisms in wide area. The purpose of this study is to clarify the effect of microorganism on Greenland ice sheet surface temperature change using satellite images of visible, near infrared and thermal infrared wavelength range and observation carried out in northwestern Greenland. We use MODIS Land Surface Temperature Product as ice sheet surface temperature. It estimates land surface temperature based on split window method using thermal infrared bands. MODIS data is bound to cover the whole of Greenland, and calculated the ratio of the temperature change per year. Analysis period is from December 2002 to November 2010. Results of calculating Greenland ice sheet surface temperature change using the MODIS data, our analysis shows that it is upward trend in the whole region. We find a striking upward trend in northern and western part of Greenland. The rate is 0.33±0.03 degree Celsius per a year from 47.5°W to 49°W. While in the coastal area from 49°W to 50.7°W, the rate is 0.26±0.06 degree Celsius per a year. This large upward trend area is the same area as dark region

  3. Efficacy of Specific Plant Products on Microorganisms Causing Dental Caries

    PubMed Central

    Kanth, M Rajini; Prakash, A Ravi; Sreenath, G; Reddy, Vikram Simha

    2016-01-01

    Introduction Dental caries and periodontal diseases are the most common oral diseases seen globally, both in developed and developing countries. Oral microorganisms that is gram positive and gram negative bacteria are known to be involved in causation of these diseases. Nowadays commercially available dentrifices and mouth rinses are known to contain ingredients that can alter the oral microbial flora and have undesirable side effects such as vomiting, diarrhoea, disarrangement of oral, intestinal flora and tooth staining. Naturally available plant products are known to be less harmful with fewer side effects and also economical for the patient. Aim The aim of this study was to determine the antimicrobial properties of 10 naturally available plant products against oral microorganisms causing caries and to check the efficacy of these products in-vitro and to use these in mouth washes and dentrifices. Materials and Methods Sample of caries material was scrapped out from the extracted teeth and transferred to liquid broth, streaked over the agar media to allow for the growth of microorganisms. Plant products like clove oil, neem, ginger-garlic paste, tea tree oil, ginger, garlic, cinnamon oil, green tea, eucalyptus oil and turmeric were used. Antimicrobial efficacy of these products, was estimated by measuring zones of inhibition in the nutrient agar media. Results Clove oil was the most effective of all products against microorganisms causing caries with zone of inhibition - 30mm followed by ginger-garlic paste - 25mm, Neem - 15mm, tea tree oil - 15mm. Conclusion Based on the above results, it can be inferred that these natural products have the maximum efficacy against microorganisms and can be recommended in dentifrices, mouth rinses, topical gels, etc. PMID:28209019

  4. L-methionine degradation potentialities of cheese-ripening microorganisms.

    PubMed

    Bonnarme, P; Lapadatescu, C; Yvon, M; Spinnler, H E

    2001-11-01

    Volatile sulphur compounds are major flavouring compounds in many traditional fermented foods including cheeses. These compounds are products of the catabolism of L-methionine by cheese-ripening microorganisms. The diversity of L-methionine degradation by such microorganisms, however, remains to be characterized. The objective of this work was to compare the capacities to produce volatile sulphur compounds by five yeasts, Geotrichum candidum, Yarrowia lipolytica, Kluyveromyces lactis, Debaryomyces hansenii, Saccharomyces cerevisiae and five bacteria, Brevibacterium linens, Corynebacterium glutamicum, Arthrobacter sp., Micrococcus lutens and Staphylococcus equorum of technological interest for cheese-ripening. The ability of whole cells of these microorganisms to generate volatile sulphur compounds from L-methionine was compared. The microorganisms produced a wide spectrum of sulphur compounds including methanethiol, dimethylsulfide, dimethyldisulfide, dimethyltrisulfide and also S-methylthioesters, which varied in amount and type according to strain. Most of the yeasts produced methanethiol, dimethylsulfide, dimethyldisulfide and dimethyltrisulfide but did not produce S-methylthioesters, apart from G. candidum that produced S-methyl thioacetate. Bacteria, especially Arth. sp. and Brevi. linens, produced the highest amounts and the greatest variety of volatile sulphur compounds includling methanethiol, sulfides and S-methylthioesters, e.g. S-methyl thioacetate, S-methyl thiobutyrate, S-methyl thiopropionate and S-methyl thioisovalerate. Cell-free extracts of all the yeasts and bacteria were examined for the activity of enzymes possibly involved in L-methionine catabolism, i.e. L-methionine demethiolase, L-methionine aminotransferase and L-methionine deaminase. They all possessed L-methionine demethiolase activity, while some (K. lactis, Deb. hansenii, Arth. sp., Staph. equorum) were deficient in L-methionine aminotransferase, and none produced L-methionine deaminase

  5. Process for producing modified microorganisms for oil treatment at high temperatures, pressures and salinity

    DOEpatents

    Premuzic, Eugene T.; Lin, Mow

    1996-02-20

    This invention relates to the preparation of new, modified organisms, through challenge growth processes, that are viable in the extreme temperature, pressure and pH conditions and salt concentrations of an oil reservoir and that are suitable for use in microbial enhanced oil recovery. The modified microorganisms of the present invention are used to enhance oil recovery and remove sulfur compounds and metals from the crude oil. The processes are comprised of steps which successively limit the carbon sources and increase the temperature, pressure and salinity of the media. This is done until microbial strains are obtained that are capable of growing in essentially crude oil as a carbon source and at a temperature range from about 70.degree. C. to 90.degree. C., at a pressure range from about 2,000 to 2,500 psi and at a salinity range from about 1.3 to 35%.

  6. Process for producing modified microorganisms for oil treatment at high temperatures, pressures and salinity

    DOEpatents

    Premuzic, E.T.; Lin, M.

    1996-02-20

    This invention relates to the preparation of new, modified organisms, through challenge growth processes, that are viable in the extreme temperature, pressure and pH conditions and salt concentrations of an oil reservoir and that are suitable for use in microbial enhanced oil recovery. The modified microorganisms of the present invention are used to enhance oil recovery and remove sulfur compounds and metals from the crude oil. The processes are comprised of steps which successively limit the carbon sources and increase the temperature, pressure and salinity of the media. This is done until microbial strains are obtained that are capable of growing in essentially crude oil as a carbon source and at a temperature range from about 70 C to 90 C, at a pressure range from about 2,000 to 2,500 psi and at a salinity range from about 1.3 to 35%. 68 figs.

  7. Advanced Materials for the Recognition and Capture of Whole Cells and Microorganisms.

    PubMed

    Bole, Amanda L; Manesiotis, Panagiotis

    2016-07-01

    Selective cell recognition and capture has recently attracted significant interest due to its potential importance for clinical, diagnostic, environmental, and security applications. Current methods for cell isolation from complex samples are largely dependent on cell size and density, with limited application scope as many of the target cells do not exhibit appreciable differences in this respect. The most recent and forthcoming developments in the area of selective recognition and capture of whole cells, based on natural receptors, as well as synthetic materials utilising physical and chemical properties of the target cell or microorganism, are highlighted. Particular focus is given to the development of cell complementary surfaces using the cells themselves as templating agents, by means of molecular imprinting, and their combination with sensing platforms for rapid cell detection in complex media. The benefits and challenges of each approach are discussed and a perspective of the future of this research area is given.

  8. Supramolecular Cationic Assemblies against Multidrug-Resistant Microorganisms: Activity and Mechanism of Action

    PubMed Central

    de Melo Carrasco, Letícia Dias; Sampaio, Jorge Luiz Mello; Carmona-Ribeiro, Ana Maria

    2015-01-01

    The growing challenge of antimicrobial resistance to antibiotics requires novel synthetic drugs or new formulations for old drugs. Here, cationic nanostructured particles (NPs) self-assembled from cationic bilayer fragments and polyelectrolytes are tested against four multidrug-resistant (MDR) strains of clinical importance. The non-hemolytic poly(diallyldimethylammonium) chloride (PDDA) polymer as the outer NP layer shows a remarkable activity against these organisms. The mechanism of cell death involves bacterial membrane lysis as determined from the leakage of inner phosphorylated compounds and possibly disassembly of the NP with the appearance of multilayered fibers made of the NP components and the biopolymers withdrawn from the cell wall. The NPs display broad-spectrum activity against MDR microorganisms, including Gram-negative and Gram-positive bacteria and yeast. PMID:25809608

  9. Models of Micro-Organisms: Children's Knowledge and Understanding of Micro-Organisms from 7 to 14 Years Old

    ERIC Educational Resources Information Center

    Byrne, Jenny

    2011-01-01

    This paper describes the expressed models that children aged 7, 11, and 14 years have about micro-organisms and microbial activity. These were elicited using a variety of data collection techniques that complemented each other, resulting in a rich dataset, and provided information about the level of knowledge and progression of ideas across the…

  10. How Rheumatoid Arthritis Can Result from Provocation of the Immune System by Microorganisms and Viruses

    PubMed Central

    Arleevskaya, Marina I.; Kravtsova, Olga A.; Lemerle, Julie; Renaudineau, Yves; Tsibulkin, Anatoly P.

    2016-01-01

    The pathogenesis of rheumatoid arthritis (RA), similar to development of a majority of inflammatory and autoimmune disorders, is largely due to an inappropriate or inadequate immune response to environmental challenges. Among these challenges, infectious agents are the undisputed leaders. Since the 1870s, an impressive list of microorganisms suspected of provoking RA has formed, and the list is still growing. Although a definite causative link between a specific infectious agent and the disease has not been established, several arguments support such a possibility. First, in the absence of a defined pathogen, the spectrum of triggering agents may include polymicrobial communities or the cumulative effect of several bacterial/viral factors. Second, the range of infectious episodes (i.e., clinical manifestations caused by pathogens) may vary in the process of RA development from preclinical to late-stage disease. Third, infectious agents might not trigger RA in all cases, but trigger it in a certain subset of the cases, or the disease onset may arise from an unfortunate combination of infections along with, for example, psychological stress and/or chronic joint tissue microtrauma. Fourth, genetic differences may have a role in the disease onset. In this review, two aspects of the problem of “microorganisms and RA” are debated. First, is there an acquired immune deficiency and, in turn, susceptibility to infections in RA patients due to the too frequent and too lengthy infections, which at last break the tolerance of self antigens? Or, second, is there a congenital deficiency in tolerance and inflammation control, which may occur even with ordinary infection frequency and duration? PMID:27582741

  11. Six Siderophore-Producing Microorganisms Identified in Biological Soil Crusts

    NASA Astrophysics Data System (ADS)

    Noonan, K.; Anbar, A. D.; Garcia-Pichel, F.; Poret-peterson, A. T.; Hartnett, H. E.

    2011-12-01

    Biological soil crusts (BSCs) are diverse microbial communities that colonize soils in arid and semi-arid environments. Cyanobacteria in BSCs are pioneer organisms that increase ecosystem habitability by providing fixed carbon (C) and nitrogen (N) as well as by reducing water run-off and increasing infiltration. Photosynthesis and N fixation, in particular, require a variety of metals in large quantities, and yet, metals are predominantly insoluble in the environments where BSCs thrive. Therefore, BSC organisms must have efficient strategies for extracting metals from soil minerals. We hypothesized that BSC microbes, particularly the cyanobacteria, produce siderophores to serve their metal-acquisition needs. Siderophores are small organic compounds that bind Fe with high affinity and are produced by a variety of microorganisms, including cyanobacteria. Most siderophores bind Fe, primarily; however, some can also bind Mo, V, and Cu. Soil siderophores are released by microbes to increase the solubility of metals from minerals and to facilitate microbial uptake. Thus, siderophores serve as chemical weathering agents and provide a direct link between soil microbes and minerals. Studying siderophore production in BSCs provides insight into how BSCs tackle the challenge of acquiring insoluble metals, and may help conservationists determine useful fertilizers for BSC growth by facilitating metal acquisition. Biological soil crusts were collected near Moab, UT. Soil slurries were prepared in deionized water and transferred to modified BG-11 agar plates. The O-CAS agar plate assay was used to screen organisms for siderophore production. Siderophore producing microbes were isolated and identified by16S rRNA gene sequencing. Cultures were then grown in 3 L batch cultures under metal limitation, and siderophore presence was monitored using the traditional liquid CAS assay. After siderophore detection, cells were removed by centrifugation, organic compounds were separated using

  12. Calculation of the radiative properties of photosynthetic microorganisms

    NASA Astrophysics Data System (ADS)

    Dauchet, Jérémi; Blanco, Stéphane; Cornet, Jean-François; Fournier, Richard

    2015-08-01

    A generic methodological chain for the predictive calculation of the light-scattering and absorption properties of photosynthetic microorganisms within the visible spectrum is presented here. This methodology has been developed in order to provide the radiative properties needed for the analysis of radiative transfer within photobioreactor processes, with a view to enable their optimization for large-scale sustainable production of chemicals for energy and chemistry. It gathers an electromagnetic model of light-particle interaction along with detailed and validated protocols for the determination of input parameters: morphological and structural characteristics of the studied microorganisms as well as their photosynthetic-pigment content. The microorganisms are described as homogeneous equivalent-particles whose shape and size distribution is characterized by image analysis. The imaginary part of their refractive index is obtained thanks to a new and quite extended database of the in vivo absorption spectra of photosynthetic pigments (that is made available to the reader). The real part of the refractive index is then calculated by using the singly subtractive Kramers-Krönig approximation, for which the anchor point is determined with the Bruggeman mixing rule, based on the volume fraction of the microorganism internal-structures and their refractive indices (extracted from a database). Afterwards, the radiative properties are estimated using the Schiff approximation for spheroidal or cylindrical particles, as a first step toward the description of the complexity and diversity of the shapes encountered within the microbial world. Finally, these predictive results are confronted to experimental normal-hemispherical transmittance spectra for validation. This entire procedure is implemented for Rhodospirillum rubrum, Arthrospira platensis and Chlamydomonas reinhardtii, each representative of the main three kinds of photosynthetic microorganisms, i.e. respectively

  13. The plastic-associated microorganisms of the North Pacific Gyre.

    PubMed

    Carson, Henry S; Nerheim, Magnus S; Carroll, Katherine A; Eriksen, Marcus

    2013-10-15

    Microorganisms likely mediate processes affecting the fate and impacts of marine plastic pollution, including degradation, chemical adsorption, and colonization or ingestion by macroorganisms. We investigated the relationship between plastic-associated microorganism communities and factors such as location, temperature, salinity, plankton abundance, plastic concentration, item size, surface roughness, and polymer type. Small plastic items from the surface of the North Pacific Gyre in 2011 were examined using scanning electron microscopy. Bacillus bacteria (mean 1664 ± 247 individuals mm(-2)) and pennate diatoms (1097 ± 154 mm(-2)) were most abundant, with coccoid bacteria, centric diatoms, dinoflagellates, coccolithophores, and radiolarians present. Bacterial abundance was patchy, but increased on foamed polystyrene. Diatom abundance increased on items with rough surfaces and at sites with high plastic concentrations. Morphotype richness increased slightly on larger fragments, and a biogeographic transition occurred between pennate diatom groups. Better characterizing this community will aid in understanding how it interacts with plastic pollution.

  14. Metabolic Engineering of Microorganisms for the Production of Higher Alcohols

    PubMed Central

    Choi, Yong Jun; Lee, Joungmin; Jang, Yu-Sin

    2014-01-01

    ABSTRACT Due to the increasing concerns about limited fossil resources and environmental problems, there has been much interest in developing biofuels from renewable biomass. Ethanol is currently used as a major biofuel, as it can be easily produced by existing fermentation technology, but it is not the best biofuel due to its low energy density, high vapor pressure, hygroscopy, and incompatibility with current infrastructure. Higher alcohols, including 1-propanol, 1-butanol, isobutanol, 2-methyl-1-butanol, and 3-methyl-1-butanol, which possess fuel properties more similar to those of petroleum-based fuel, have attracted particular interest as alternatives to ethanol. Since microorganisms isolated from nature do not allow production of these alcohols at high enough efficiencies, metabolic engineering has been employed to enhance their production. Here, we review recent advances in metabolic engineering of microorganisms for the production of higher alcohols. PMID:25182323

  15. Probiotic fermented sausage: viability of probiotic microorganisms and sensory characteristics.

    PubMed

    Rouhi, M; Sohrabvandi, S; Mortazavian, A M

    2013-01-01

    Probiotics are from functional foods that bring health benefits for humans. Nowadays, a major development in functional foods is related to food containing probiotic cultures, mainly lactic acid bacteria or bifidobacteria. Probiotics must be alive and ingested in sufficient amounts to exert the positive effects on the health and the well-being of the host. Therefore, viability of probiotic products (the minimum viable probiotic cells in each gram or milliliter of product till the time of consumption) is their most important characteristic. However, these organisms often show poor viability in fermented products due to their detrimental conditions. Today, the variety of fermented meat products available around the world is nearly equal to that of cheese. With meat products, raw fermented sausages could constitute an appropriate vehicle for such microorganisms into the human gastrointestinal tract. In present article, the viability of probiotic microorganisms in fermented sausage, the main factors affect their viability, and the sensorial characteristics of final product are discussed.

  16. Locomotion of a microorganism in weakly viscoelastic liquids.

    PubMed

    De Corato, M; Greco, F; Maffettone, P L

    2015-11-01

    In the present work we study the motion of microorganisms swimming by an axisymmetric distribution of surface tangential velocity in a weakly viscoelastic fluid. The second-order fluid constitutive equation is used to model the suspending fluid, while the well-known "squirmer model" [M. J. Lighthill, Comm. Pure Appl. Math. 5, 109 (1952); J. R. Blake, J. Fluid Mech. 46, 199 (1971)] is employed to describe the organism propulsion mechanism. A regular perturbation expansion up to first order in the Deborah number is performed, and the generalized reciprocity theorem from Stokes flow theory is then used, to derive analytical formulas for the squirmer velocity. Results show that "neutral" squirmers are unaffected by viscoelasticity, whereas "pullers" and "pushers" are slowed down and hastened, respectively. The power dissipated by the swimming microorganism and the "swimming efficiency" are also analytically quantified.

  17. Use of microorganism to improve the strength of cement mortar

    SciTech Connect

    Ghosh, P.; Mandal, S. . E-mail: sarojmandal2001@yahoo.co.in; Chattopadhyay, B.D.; Pal, S.

    2005-10-01

    This study describes a method of strength improvement of cement-sand mortar by the microbiologically induced mineral precipitation. A thermophilic anaerobic microorganism is incorporated at different cell concentrations with the mixing water. The study showed that a 25% increase in 28 day compressive strength of cement mortar was achieved with the addition of about 10{sup 5} cell/ml of mixing water. The strength improvement is due to growth of filler material within the pores of the cement-sand matrix as shown by the scanning electron microscopy. The modification in pore size distribution and total pore volume of cement-sand mortar due to such growth is also noted. E. coli microorganisms were also used in the cement mortar for comparison, but no improvement in strength was observed.

  18. Strategies of preserving lipids in microorganism after fermentation.

    PubMed

    Zhang, Xiaolei; Yan, Song; Tyagi, Rajeshwar Dayal

    2015-09-01

    Microbial oil is accumulated by microorganisms as stored energy during cultivation, and will be degraded to generate energy when they are not able to obtain external energy source. As the lipid is the desired production, the in situ degradation of oil by microorganisms after fermentation or during downstream processing has to be prevented. This study investigated the effect of pH, thermal, salinity, bead milling, ultrasonication, and microwave treatment on the viability of Trichosporon oleaginosus when it was used for lipid production. The cells in broth were completely inactivated with the treatment of pH 1 and 2 for 1h, temperature 80 °C for 10 min, ultrasonication for 8 min, and microwave for 6 min, respectively. It was observed that these treatments had no impact on final product (biodiesel) composition and were considered as safe and efficient methods to preserve lipid in cells.

  19. Direct measurement of the flow field around swimming microorganisms

    NASA Astrophysics Data System (ADS)

    Polin, Marco; Drescher, Knut; Goldstein, Raymond E.; Michel, Nicolas; Tuval, Idan

    2010-11-01

    Swimming microorganisms create flows that influence their mutual interactions and modify the rheology of their suspensions. While extensively studied theoretically, these flows have not been measured in detail around any freely-swimming microorganism. We report such measurements for the microphytes Volvox carteri and Chlamydomonas reinhardtii. The minute (˜0.3%) density excess of V. carteri over water leads to a strongly dominant Stokeslet contribution, with the widely-assumed stresslet flow only a correction to the subleading source dipole term. This implies that suspensions of V. carteri have features similar to suspensions of sedimenting particles. The flow in the region around C. reinhardtii where significant hydrodynamic interaction is likely to occur differs qualitatively from a "puller" stresslet, and can be described by a simple three-Stokeslet model.

  20. Direct Measurement of the Flow Field around Swimming Microorganisms

    NASA Astrophysics Data System (ADS)

    Drescher, Knut; Goldstein, Raymond E.; Michel, Nicolas; Polin, Marco; Tuval, Idan

    2010-10-01

    Swimming microorganisms create flows that influence their mutual interactions and modify the rheology of their suspensions. While extensively studied theoretically, these flows have not been measured in detail around any freely-swimming microorganism. We report such measurements for the microphytes Volvox carteri and Chlamydomonas reinhardtii. The minute (˜0.3%) density excess of V. carteri over water leads to a strongly dominant Stokeslet contribution, with the widely-assumed stresslet flow only a correction to the subleading source dipole term. This implies that suspensions of V. carteri have features similar to suspensions of sedimenting particles. The flow in the region around C. reinhardtii where significant hydrodynamic interaction is likely to occur differs qualitatively from a puller stresslet, and can be described by a simple three-Stokeslet model.

  1. Ecological aspects of microorganisms inhabiting uranium mill tailings

    USGS Publications Warehouse

    Miller, C.L.; Landa, E.R.; Updegraff, D.M.

    1987-01-01

    Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques. Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereas Bacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth. ?? 1987 Springer-Verlag New York Inc.

  2. Ecological aspects of microorganisms inhabiting uranium mill tailings.

    PubMed

    Miller, C L; Landa, E R; Updegraff, D M

    1987-09-01

    Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques.Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereasBacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth.

  3. [Instrumental technics for the detection of microorganisms in brewing].

    PubMed

    Orive, M

    1995-03-01

    Although modern production techniques keep microorganism levels very low in both finished beer and in beer process, there is still concern about early detection and prevention of accidental proliferation of brewery spoilage microorganisms. Traditional microbiological techniques can detect such low levels, but no results are obtained before 3 to 6 days of incubation. That is why rapid or even "instant" techniques are a main objective of research in the brewing industry. In this work, some instrumental techniques (DEFT, MMCF, impedance, pH, immunology and PCR based techniques, bioluminometry) are described and considered from the point of view of their regular use in brewery Microbiological Quality Assurance Laboratories. Real case experiences are brought forward.

  4. Microorganism and filamentous fungi drive evolution of plant synapses

    PubMed Central

    Baluška, František; Mancuso, Stefano

    2013-01-01

    In the course of plant evolution, there is an obvious trend toward an increased complexity of plant bodies, as well as an increased sophistication of plant behavior and communication. Phenotypic plasticity of plants is based on the polar auxin transport machinery that is directly linked with plant sensory systems impinging on plant behavior and adaptive responses. Similar to the emergence and evolution of eukaryotic cells, evolution of land plants was also shaped and driven by infective and symbiotic microorganisms. These microorganisms are the driving force behind the evolution of plant synapses and other neuronal aspects of higher plants; this is especially pronounced in the root apices. Plant synapses allow synaptic cell–cell communication and coordination in plants, as well as sensory-motor integration in root apices searching for water and mineral nutrition. These neuronal aspects of higher plants are closely linked with their unique ability to adapt to environmental changes. PMID:23967407

  5. Newly designed, simple relief phase contrast for microscopy of microorganisms.

    PubMed

    Zižka, Z

    2010-11-01

    A new method providing a relief phase contrast for investigation of microorganisms by optical microscopy used a neutral filter Zeiss NG 10/1 that could be controllably slid at a certain azimuthal angle below the aperture condenser diaphragm of the microscope phase contrast. Two ways of application are described depending on the type of the microscope: (1) in a special holder, and (2) fixed on a rubber ring. The device enabled us to obtain excellent results in the area of both optical microscopy and microphotography. With the microorganisms visualized, a better resolution, higher contrast and a significant 3D effect were obtained; outer morphology and organelles (chloroplasts, nuclei, granules, oil reserve vacuoles, etc.) could also be investigated.

  6. Microorganism and filamentous fungi drive evolution of plant synapses.

    PubMed

    Baluška, František; Mancuso, Stefano

    2013-01-01

    In the course of plant evolution, there is an obvious trend toward an increased complexity of plant bodies, as well as an increased sophistication of plant behavior and communication. Phenotypic plasticity of plants is based on the polar auxin transport machinery that is directly linked with plant sensory systems impinging on plant behavior and adaptive responses. Similar to the emergence and evolution of eukaryotic cells, evolution of land plants was also shaped and driven by infective and symbiotic microorganisms. These microorganisms are the driving force behind the evolution of plant synapses and other neuronal aspects of higher plants; this is especially pronounced in the root apices. Plant synapses allow synaptic cell-cell communication and coordination in plants, as well as sensory-motor integration in root apices searching for water and mineral nutrition. These neuronal aspects of higher plants are closely linked with their unique ability to adapt to environmental changes.

  7. Survival strategies of microorganisms in extreme saline environments

    NASA Astrophysics Data System (ADS)

    Imhoff, J. F.

    Halophilic representatives are found in all main lines of evolutionary descendence of microbes: in archaebacteria, Gram-negative and Gram-positive eubacteria, and also in eucaryotes. In principe all halophilic microorganisms have to adapt their surface and membrane structures to their highly ionic environments. Concerning their intracellular compartment two different strategies have been developed: Inorganic ions are largely excluded in some microorganisms while such ions are actively accumulated in others. In particular the second group of organisms has to adapt the whole metabolic machinery to the highly ionic conditions of several molar salts, whereas in the first group only the outer surface of the cytoplasmic membrane and the extracytoplasmic structures are in contact with high concentrations of inorganic ions. In this latter group, a variety of organic solutes is accumulated in response to increases of the salinity of the environment.

  8. Optimization of industrial microorganisms: recent advances in synthetic dynamic regulators.

    PubMed

    Min, Byung Eun; Hwang, Hyun Gyu; Lim, Hyun Gyu; Jung, Gyoo Yeol

    2017-01-01

    Production of biochemicals by industrial fermentation using microorganisms requires maintaining cellular production capacity, because maximal productivity is economically important. High-productivity microbial strains can be developed using static engineering, but these may not maintain maximal productivity throughout the culture period as culture conditions and cell states change dynamically. Additionally, economic reasons limit heterologous protein expression using inducible promoters to prevent metabolic burden for commodity chemical and biofuel production. Recently, synthetic and systems biology has been used to design genetic circuits, precisely controlling gene expression or influencing genetic behavior toward a desired phenotype. Development of dynamic regulators can maintain cellular phenotype in a maximum production state in response to factors including cell concentration, oxygen, temperature, pH, and metabolites. Herein, we introduce dynamic regulators of industrial microorganism optimization and discuss metabolic flux fine control by dynamic regulators in response to metabolites or extracellular stimuli, robust production systems, and auto-induction systems using quorum sensing.

  9. Metabolic engineering of microorganisms for the production of higher alcohols.

    PubMed

    Choi, Yong Jun; Lee, Joungmin; Jang, Yu-Sin; Lee, Sang Yup

    2014-09-02

    Due to the increasing concerns about limited fossil resources and environmental problems, there has been much interest in developing biofuels from renewable biomass. Ethanol is currently used as a major biofuel, as it can be easily produced by existing fermentation technology, but it is not the best biofuel due to its low energy density, high vapor pressure, hygroscopy, and incompatibility with current infrastructure. Higher alcohols, including 1-propanol, 1-butanol, isobutanol, 2-methyl-1-butanol, and 3-methyl-1-butanol, which possess fuel properties more similar to those of petroleum-based fuel, have attracted particular interest as alternatives to ethanol. Since microorganisms isolated from nature do not allow production of these alcohols at high enough efficiencies, metabolic engineering has been employed to enhance their production. Here, we review recent advances in metabolic engineering of microorganisms for the production of higher alcohols.

  10. [Update of antimicrobial resistance in Gram-positive microorganisms].

    PubMed

    Cercenado, Emilia

    2010-12-01

    In the last few decades, resistance among Gram-positive microorganisms to classical antimicrobials as well as the emergence of resistance to new antimicrobials has been observed in our environment. Methicillin resistance among Staphylococcus aureus and coagulase-negative staphylococci seems to have stabilized at around 30% and 70%, respectively, however, multiresistance of these species to other antimicrobials, emergence of linezolid resistance, and decreased susceptibility to glycopeptides is a cause of concern. Daptomycin has good antimicrobial activity, although some strains with slightly increased MICs have been detected. Among enterococci, vancomycin resistance is less than 5%, but multiresistance among these microorganisms, emerging linezolid resistance and reports of some isolates with decreased susceptibility to daptomycin are worrying. Adequate use of antimicrobials could help to prevent the increase in resistance and dissemination of these pathogens and will allow their efficacy to be guaranteed in the future.

  11. Raft-like membrane domains in pathogenic microorganisms.

    PubMed

    Farnoud, Amir M; Toledo, Alvaro M; Konopka, James B; Del Poeta, Maurizio; London, Erwin

    2015-01-01

    The lipid bilayer of the plasma membrane is thought to be compartmentalized by the presence of lipid-protein microdomains. In eukaryotic cells, microdomains composed of sterols and sphingolipids, commonly known as lipid rafts, are believed to exist, and reports on the presence of sterol- or protein-mediated microdomains in bacterial cell membranes are also appearing. Despite increasing attention, little is known about microdomains in the plasma membrane of pathogenic microorganisms. This review attempts to provide an overview of the current state of knowledge of lipid rafts in pathogenic fungi and bacteria. The current literature on characterization of microdomains in pathogens is reviewed, and their potential role in growth, pathogenesis, and drug resistance is discussed. Better insight into the structure and function of membrane microdomains in pathogenic microorganisms might lead to a better understanding of their pathogenesis and development of raft-mediated approaches for therapy.

  12. Metabolic engineering towards biotechnological production of carotenoids in microorganisms.

    PubMed

    Lee, P C; Schmidt-Dannert, C

    2002-10-01

    Carotenoids are important natural pigments produced by many microorganisms and plants. Traditionally, carotenoids have been used in the feed, food and nutraceutical industries. The recent discoveries of health-related beneficial properties attributed to carotenoids have spurred great interest in the production of structurally diverse carotenoids for pharmaceutical applications. The availability of a considerable number of microbial and plant carotenoid genes that can be functionally expressed in heterologous hosts has opened ways for the production of diverse carotenoid compounds in heterologous systems. In this review, we will describe the recent progress made in metabolic engineering of non-carotenogenic microorganisms for improved carotenoid productivity. In addition, we will discuss the application of combinatorial and evolutionary strategies to carotenoid pathway engineering to broaden the diversity of carotenoid structures synthesized in recombinant hosts.

  13. Food environments select microorganisms based on selfish energetic behavior.

    PubMed

    Mora, Diego; Arioli, Stefania; Compagno, Concetta

    2013-01-01

    Nutrient richness, and specifically the abundance of mono- and disaccharides that characterize several food matrixes, such as milk and grape juice, has allowed the speciation of lactic acid bacteria and yeasts with a high fermentation capacity instead of energetically favorable respiratory metabolism. In these environmental contexts, rapid sugar consumption and lactic acid or ethanol production, accumulation, and tolerance, together with the ability to propagate in the absence of oxygen, are several of the "winning" traits that have apparently evolved and become specialized to perfection in these fermenting microorganisms. Here, we summarize and discuss the evolutionary context that has driven energetic metabolism in food-associated microorganisms, using the dairy species Lactococcus lactis and Streptococcus thermophilus among prokaryotes and the bakers' yeast Saccharomyces cerevisiae among eukaryotes as model organisms.

  14. Synthesis of biosurfactants and their advantages to microorganisms and mankind.

    PubMed

    Cameotra, Swaranjit Singh; Makkar, Randhir S; Kaur, Jasminder; Mehta, S K

    2010-01-01

    Biosurfactants are surface-active compounds synthesized by a wide variety of microorganisms. They are molecules that have both hydrophobic and hydrophilic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures--lipopeptides, glycolipids, neutral lipids and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. The low water solubility of these hydrophobic compounds limits their availability to microorganisms, which is a potential problem for bioremediation of contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of pollutants has potential applications in bioremediation. Not only are the biosurfactants useful in a variety of industrial processes, they are also of vital importance to the microbes in adhesion, emulsification, bioavailability, desorption and defense strategy. These interesting facts are discussed in this chapter.

  15. Locomotion of a microorganism in weakly viscoelastic liquids

    NASA Astrophysics Data System (ADS)

    De Corato, M.; Greco, F.; Maffettone, P. L.

    2015-11-01

    In the present work we study the motion of microorganisms swimming by an axisymmetric distribution of surface tangential velocity in a weakly viscoelastic fluid. The second-order fluid constitutive equation is used to model the suspending fluid, while the well-known "squirmer model" [M. J. Lighthill, Comm. Pure Appl. Math. 5, 109 (1952), 10.1002/cpa.3160050201; J. R. Blake, J. Fluid Mech. 46, 199 (1971), 10.1017/S002211207100048X] is employed to describe the organism propulsion mechanism. A regular perturbation expansion up to first order in the Deborah number is performed, and the generalized reciprocity theorem from Stokes flow theory is then used, to derive analytical formulas for the squirmer velocity. Results show that "neutral" squirmers are unaffected by viscoelasticity, whereas "pullers" and "pushers" are slowed down and hastened, respectively. The power dissipated by the swimming microorganism and the "swimming efficiency" are also analytically quantified.

  16. [Effect of microorganism for polycyclic aromatic hydrocarbons (PAHs) sorption on surface sediments and soils].

    PubMed

    Luo, Xue-Mei; He, Meng-Chang; Liu, Chang-Ming

    2007-02-01

    Influence of microorganism for polycyclic aromatic hydrocarbons (PAHs) sorption on surface sediments and soils in Yellow River Delta was studied. The results indicated that phenanthrene and benzo[a]pyrene could be adsorbed or biodegraded by Bacillus subtilis, and 98% phenanthrene and 85% benzo[a]pyrene was eliminated by microorganism in adsorption process. Sorption isotherms of soils and sediments with and without microorganism were described by linear isotherm equation. Adsorption capacity of samples with microorganism increased about 35 times than that of without microorganism, but benzo[a] pyrene adsorption capacity decreased about 2/3. In desorption process, samples with microorganism desorbed less phenanthrene than without microorganism, but more benzo[a]pyrene. Microorganism plays an important role in adsorption process.

  17. A SYSTEMATIC COMPARISON OF THE ELECTROKINETIC PROPERTIES OF ENVIRONMENTALLY IMPORTANT MICROORGANISMS IN WATER

    EPA Science Inventory

    The surface charge of microorganisms is an important factor controlling their stability in aqueous environments and removal during water tretment practices. The electrophoretic mobility (EPM) of a number of environmentally important microorganisms in phosphate buffers was measur...

  18. Recovery of medically important microorganisms from Apollo astronauts

    NASA Technical Reports Server (NTRS)

    Taylor, G. R.

    1974-01-01

    Microbiological samples were obtained from the crewmembers of the Apollo 13, 14, 15, 16, and 17 spaceflights. These specimens were analyzed for the presence of medically important microorganisms with Staphylococcus aureus, Pseudomonas aeruginosa, Tricophyton mentagrophytes, Tricophyton rubrum, and Candida albicans being discussed in detail. Preflight isolation of crewmembers was found to coincide with a complete absence of inflight disease events and is recommended for future spaceflights. No autoinfection response (microbial shock) occurred after any of the reported spaceflights.

  19. Survey, purification, and properties of sugar phosphate phosphohydrolase among microorganisms.

    PubMed

    Choy, F Y; Lee, Y P

    1983-12-01

    Sugar phosphate phosphohydrolase was purified approximately 500- to 600-fold to apparent homogeneity from Escherichia coli B, Escherichia coli C, Escherichia coli var. communior, Escherichia acidilactici, Enterobacter aerogenes, Neisseria meningitidis, and Saccharomyces cereviseae. The molecular weights of the enzyme as estimated by gel filtration ranged from 97 X 10(3) to 101 X 10(3). The enzyme was composed of two subunits with the same molecular weight which ranged from 50 X 10(3) to 52 X 10(3), as determined by sodium dodecyl sulfate gel electrophoresis. Homogeneous enzyme preparations hydrolyse all the tested alpha-D-aldohexose 1-phosphate, D-(keto or aldo)hexose 6-phosphate, and pentose phosphate substrates significantly. When the microorganisms were transferred from growth medium with 1% glucose to that without glucose, there were dramatic increases in both the specific and total enzyme activities. At least three isozymes appeared to be present in S. cereviseae, and two appeared to be present in E. coli B, E. coli var. communior, and N. meningitidis. Rabbit antiserum immunized against sugar phosphate phosphohydrolase purified from E. coli B cross-reacted with both the crude extracts and purified preparations of the enzyme from the other microorganisms. The presence of neither sugar phosphate phosphohydrolase activity nor immunocrossreacting material was detected in the following microorganisms: Aspergillus niger, Azotobacter chroococcum, Bacillus subtilis, Bacillus pumilis, Citrobacter freundii, Clostridium butyricum, Corynebacterium xerosis, Flavobacterium aquatile, Flavobacterium synxanthum, Lactobacillus bulgaricus, Micrococcus coralinus, Neisseria perflava, Neurospora crassa, Penicilium expansum, Penicilium notatum, Proteus mirabilis, Proteus vulgaris, Pseudomonas fluorescens, Saccharomyces fermenti, Sarcina lutea, and Streptomyces antibioticus. At present, no conclusive relationship can be established between the phosphoenolpyruvate phosphotransferase

  20. Electrical impedance measurements: rapid method for detecting and monitoring microorganisms.

    PubMed Central

    Cady, P; Dufour, S W; Shaw, J; Kraeger, S J

    1978-01-01

    A conceptually simple and east-to-use technique is described that uses continuous impedance measurements for automated monitoring of microbial growth and metabolism. The method has been applied to a wide range of microorganisms. Optical clarity is not required. The sensitivity and reproducibility of the method are demonstrated. The mechanism whereby microbial growth alters the impedance of the medium is discussed, as well as potential applications of the method to clinical microbiology. Images PMID:348718