Production of volatile metabolites by grape-associated microorganisms.

PubMed

Verginer, Markus; Leitner, Erich; Berg, Gabriele

2010-07-28

Plant-associated microorganisms fulfill important functions for their hosts. Whereas promotion of plant growth and health is well-studied, little is known about the impact of microorganisms on plant or fruit flavor. To analyze the production of volatiles of grape-associated microorganisms, samples of grapes of the red cultivar 'Blaufraenkisch' were taken during harvest time from four different vineyards in Burgenland (Austria). The production of volatiles was analyzed for the total culturable microbial communities (bacteria, yeasts, fungi) found on and in the grapes as well as for single isolates. The microbial communities produced clearly distinct aroma profiles for each vineyard and phylogenetic group. Furthermore, half of the grape-associated microorganisms produced a broad spectrum of volatile organic compounds. Exemplary, the spectrum was analyzed more in detail for three single isolates of Paenibacillus sp., Sporobolomyces roseus , and Aureobasidium pullulans . Well-known and typical flavor components of red wine were detected as being produced by microbes, for example, 2-methylbutanoic acid, 3-methyl-1-butanol, and ethyl octanoate.

Biodiesel production by various oleaginous microorganisms from organic wastes.

PubMed

Cho, Hyun Uk; Park, Jong Moon

2018-05-01

Biodiesel is a biodegradable and renewable fuel. A large amount of research has considered microbial oil production using oleaginous microorganisms, but the commercialization of microbial lipids produced in this way remains uncertain due to the high cost of feedstock or low lipid yield. Microbial lipids can be typically produced by microalgae, yeasts, and bacteria; the lipid yields of these microorganisms can be improved by using sufficient concentrations of organic carbon sources. Therefore, combining low-cost organic compounds contained in organic wastes with cultivation of oleaginous microorganisms can be a promising approach to obtain commercial viability. However, to achieve effective bioconversion of low-cost substrates to microbial lipids, the characteristics of each microorganism and each substrate should be considered simultaneously. This article discusses recent approaches to developing cost-effective microbial lipid production processes that use various oleaginous microorganisms and organic wastes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Diversity of cultivable β-glycosidase-producing micro-organisms isolated from the soil of a ginseng field and their ginsenosides-hydrolysing activity.

PubMed

Fu, Y; Yin, Z; Wu, L; Yin, C

2014-02-01

This research aimed to explore the diversity of cultivable β-glycosidase-producing micro-organisms in ginseng field soil. Fifty-three strains showing β-glucosidase activity were isolated from a ginseng field, using a newly designed Esculin-R2A agar. All the isolated strains belonged to the genus Agrobacterium, Arthrobacter, Burkholderia, Dyella, Edaphobacter, Luteibacter, Mucilaginibacter, Paenibacillus, Phenylobacterium, Pseudomonas, Sphingomonas and Streptomyces. The main β-glucosidase-producing micro-organisms in the ginseng field soil were Sphingomonas, Burkholderia, Luteibacter and Streptomyces, while concentrations of Agrobacterium, Arthrobacter, Paenibacillus and Pseudomonas were relatively low. Of these micro-organisms, the strain GS 09 could hydrolyse major ginsenosides Rb1, Rb2 and Rc to the active metabolite compound K. The strain GS 09 belonged to the genus Sphingomonas, and its 16S rRNA gene sequence showed 100% similarities with that of Sphingomonas asaccharolytica. This is the first study to provide information of cultivable β-glycosidase-producing micro-organisms in ginseng field soil. The strain GS 09 has potential to be applied on the preparation for minor ginsenoside C-K in pharmaceutical industry. © 2013 The Society for Applied Microbiology.

Microorganisms associated with chromosome destruction and reproductive isolation between two insect species.

PubMed

Breeuwer, J A; Werren, J H

1990-08-09

Microorganisms have been implicated in causing cytoplasmic incompatibility in a variety of insect species, including mosquitoes, fruitflies, beetles and wasps. The effect is typically unidirectional: incompatible crosses produce no progeny or sterile males, whereas the reciprocal crosses produce normal progeny. The parasitic wasp Nasonia vitripennis is one of the few species in which the cytogenetic mechanism of incompatibility is known. In this species the paternal chromosome set forms a tangled mass in a fertilized egg and is eventually lost. Here we report that cytoplasmic microorganisms are associated with complete bidirectional incompatibility between N. vitripennis and a closely related sympatric species, N. giraulti. Microorganisms can be seen in the eggs of both species. Hybrid offspring are normally not produced in crosses between the two species, but do occur after elimination of the microorganisms by antibiotic treatment. A cytogenetic and genetic study shows that bidirectional interspecific incompatibility is due to improper condensation of the paternal chromosomes. Microorganism-mediated reproductive isolation is of interest because it could provide a rapid mode of speciation. The mechanism of incompatibility in Nasonia is also of interest as a potential tool for studying chromosome imprinting and chromosome condensation.

Human recombinant lysosomal enzymes produced in microorganisms.

PubMed

Espejo-Mojica, Ángela J; Alméciga-Díaz, Carlos J; Rodríguez, Alexander; Mosquera, Ángela; Díaz, Dennis; Beltrán, Laura; Díaz, Sergio; Pimentel, Natalia; Moreno, Jefferson; Sánchez, Jhonnathan; Sánchez, Oscar F; Córdoba, Henry; Poutou-Piñales, Raúl A; Barrera, Luis A

2015-01-01

Lysosomal storage diseases (LSDs) are caused by accumulation of partially degraded substrates within the lysosome, as a result of a function loss of a lysosomal protein. Recombinant lysosomal proteins are usually produced in mammalian cells, based on their capacity to carry out post-translational modifications similar to those observed in human native proteins. However, during the last years, a growing number of studies have shown the possibility to produce active forms of lysosomal proteins in other expression systems, such as plants and microorganisms. In this paper, we review the production and characterization of human lysosomal proteins, deficient in several LSDs, which have been produced in microorganisms. For this purpose, Escherichia coli, Saccharomyces cerevisiae, Pichia pastoris, Yarrowia lipolytica, and Ogataea minuta have been used as expression systems. The recombinant lysosomal proteins expressed in these hosts have shown similar substrate specificities, and temperature and pH stability profiles to those produced in mammalian cells. In addition, pre-clinical results have shown that recombinant lysosomal enzymes produced in microorganisms can be taken-up by cells and reduce the substrate accumulated within the lysosome. Recently, metabolic engineering in yeasts has allowed the production of lysosomal enzymes with tailored N-glycosylations, while progresses in E. coli N-glycosylations offer a potential platform to improve the production of these recombinant lysosomal enzymes. In summary, microorganisms represent convenient platform for the production of recombinant lysosomal proteins for biochemical and physicochemical characterization, as well as for the development of ERT for LSD. Copyright © 2015 Elsevier Inc. All rights reserved.

Engineering biofuel tolerance in non-native producing microorganisms.

PubMed

Jin, Hu; Chen, Lei; Wang, Jiangxin; Zhang, Weiwen

2014-01-01

Large-scale production of renewable biofuels through microbiological processes has drawn significant attention in recent years, mostly due to the increasing concerns on the petroleum fuel shortages and the environmental consequences of the over-utilization of petroleum-based fuels. In addition to native biofuel-producing microbes that have been employed for biofuel production for decades, recent advances in metabolic engineering and synthetic biology have made it possible to produce biofuels in several non-native biofuel-producing microorganisms. Compared to native producers, these non-native systems carry the advantages of fast growth, simple nutrient requirements, readiness for genetic modifications, and even the capability to assimilate CO2 and solar energy, making them competitive alternative systems to further decrease the biofuel production cost. However, the tolerance of these non-native microorganisms to toxic biofuels is naturally low, which has restricted the potentials of their application for high-efficiency biofuel production. To address the issues, researches have been recently conducted to explore the biofuel tolerance mechanisms and to construct robust high-tolerance strains for non-native biofuel-producing microorganisms. In this review, we critically summarize the recent progress in this area, focusing on three popular non-native biofuel-producing systems, i.e. Escherichia coli, Lactobacillus and photosynthetic cyanobacteria. Copyright © 2014 Elsevier Inc. All rights reserved.

Materials and methods for efficient succinate and malate production

DOEpatents

Jantama, Kaemwich; Haupt, Mark John; Zhang, Xueli; Moore, Jonathan C; Shanmugam, Keelnatham T; Ingram, Lonnie O'Neal

2014-04-08

Genetically engineered microorganisms have been constructed to produce succinate and malate in mineral salt media in pH-controlled batch fermentations without the addition of plasmids or foreign genes. The subject invention also provides methods of producing succinate and malate comprising the culture of genetically modified microorganisms.

Shiga toxin-producing escherichia coli: detection, differentiation, and implications for food safety

USDA-ARS?s Scientific Manuscript database

All unprocessed food products typically harbor microorganisms. Some foods and the components that go into food production may contain pathogenic microorganisms such as Shiga toxin-producing Escherichia coli (STECs). When consumed, these STECs can cause serious illness or even death. In 2011, an out...

Microbial Endocrinology in the Pathogenesis of Infectious Disease.

PubMed

Lyte, Mark

2016-04-01

Microbial endocrinology represents the intersection of two seemingly disparate fields, microbiology and neurobiology, and is based on the shared presence of neurochemicals that are exactly the same in host as well as in the microorganism. The ability of microorganisms to not only respond to, but also produce, many of the same neurochemicals that are produced by the host, such as during periods of stress, has led to the introduction of this evolutionary-based mechanism which has a role in the pathogenesis of infectious disease. The consideration of microbial endocrinology-based mechanisms has demonstrated, for example, that the prevalent use of catecholamine-based synthetic drugs in the clinical setting contributes to the formation of biofilms in indwelling medical devices. Production of neurochemicals by microorganisms most often employs the same biosynthetic pathways as those utilized by the host, indicating that acquisition of host neurochemical-based signaling system in the host may have been acquired due to lateral gene transfer from microorganisms. That both host and microorganism produce and respond to the very same neurochemicals means that there is bidirectionality contained with the theoretical underpinnings of microbial endocrinology. This can be seen in the role of microbial endocrinology in the microbiota-gut-brain axis and its relevance to infectious disease. Such shared pathways argue for a role of microorganism-neurochemical interactions in infectious disease.

Emulsification of hydrocarbons by subsurface bacteria

USGS Publications Warehouse

Francy, D.S.; Thomas, J.M.; Raymond, R.L.; Ward, C.H.

1991-01-01

Biosurfactants have potential for use in enhancement of in situ biorestoration by increasing the bioavailability of contaminants. Microorganisms isolated from biostimulated, contaminated and uncontaminated zones at the site of an aviation fuel spill and hydrocarbon-degrading microorganisms isolated from sites contaminated with unleaded gasoline were examined for their abilities to emulsify petroleum hydrocarbons. Emulsifying ability was quantified by a method involving agitation and visual inspection. Biostimulated-zone microbes and hydrocarbon-degrading microorganisms were the best emulsifiers as compared to contaminated and uncontaminated zone microbes. Biostimulation (nutrient and oxygen addition) may have been the dominant factor which selected for and encouraged growth of emulsifiers; exposure to hydrocarbon was also important. Biostimulated microorganisms were better emulsifiers of aviation fuel (the contaminant hydrocarbon) than of heavier hydrocarbon to which they were not previously exposed. By measuring surface tension changes of culture broths, 11 out of 41 emulsifiers tested were identified as possible biosurfactant producers and two isolates produced large surface tension reductions indicating the high probability of biosurfactant production.Biosurfactants have potential for use in enhancement of in situ biorestoration by increasing the bioavailability of contaminants. Microorganisms isolated from biostimulated, contaminated and uncontaminated zones at the site of an aviation fuel spill and hydrocarbon-degrading microorganisms isolated from sites contaminated with unleaded gasoline were examined for their abilities to emulsify petroleum hydrocarbons. Emulsifying ability was quantified by a method involving agitation and visual inspection. Biostimulated-zone microbes and hydrocarbon-degrading microorganisms were the best emulsifiers as compared to contaminated and uncontaminated zone microbes. Biostimulation (nutrient and oxygen addition) may have been the dominant factor which selected for and encouraged growth of emulsifiers; exposure to hydrocarbon was also important. Biostimulated microorganisms were better emulsifiers of aviation fuel (the contaminant hydrocarbon) than of heavier hydrocarbon to which they were not previously exposed. By measuring surface tension changes of culture broths, 11 out of 41 emulsifiers tested were identified as possible biosurfactant producers and two isolates produced large surface tension reductions, indicating a high probability of biosurfactant production.

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.

Anaerobic thermophilic culture system

DOEpatents

Ljungdahl, Lars G.; Wiegel, Jurgen K. W.

1981-01-01

A mixed culture system of the newly discovered microorganism Thermoanaerobacter ethanolicus ATCC31550 and the microorganism Clostridium thermocellum ATCC31549 is described. In a mixed nutrient culture medium that contains cellulose, these microorganisms have been coupled and cultivated to efficiently ferment cellulose to produce recoverable quantities of ethanol under anaerobic, thermophilic conditions.

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.

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.

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.

A rapid, efficient and sensitive plate assay for detection and screening of l-asparaginase-producing microorganisms.

PubMed

Mahajan, Richi V; Saran, Saurabh; Saxena, Rajendra K; Srivastava, Ayush K

2013-04-01

l-Asparaginase-producing microbes are conventionally screened on phenol red l-asparagine-containing plates. However, sometimes the contrast of the zone obtained (between yellow and pink) is not very sharp and distinct. In the present investigation, an improved method for screening of the microorganisms producing extracellular l-asparaginase is reported wherein bromothymol blue (BTB) is incorporated as pH indicator in l-asparagine-containing medium instead of phenol red. Plates containing BTB at acidic pH are yellow and turn dark blue at alkaline pH. Thus, a dense dark blue zone is formed around microbial colonies producing l-asparaginase, differentiating between enzyme producers and non-producers. The present method is more sensitive and accurate than the conventional method for screening of both fungi and bacteria producing extracellular l-asparaginase. Furthermore, BTB gives a transient green colour at neutral pH (7.0) and dark blue colour at higher pH 8.0-9.0, indicating the potency of the microorganism for l-asparaginase production. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Heat-stable, FE-dependent alcohol dehydrogenase for aldehyde detoxification

DOEpatents

Elkins, James G.; Clarkson, Sonya

2018-04-24

The present invention relates to microorganisms and polypeptides for detoxifying aldehydes associated with industrial fermentations. In particular, a heat-stable, NADPH- and iron-dependent alcohol dehydrogenase was cloned from Thermoanaerobacter pseudethanolicus 39E and displayed activity against a number of aldehydes including inhibitory compounds that are produced during the dilute-acid pretreatment process of lignocellulosic biomass before fermentation to biofuels. Methods to use the microorganisms and polypeptides of the invention for improved conversion of bio mass to biofuel are provided as well as use of the enzyme in metabolic engineering strategies for producing longer-chain alcohols from sugars using thermophilic, fermentative microorganisms.

Recombinant Zymomonas for pentose fermentation

DOEpatents

Picataggio, S.K.; Zhang, M.; Eddy, C.K.; Deanda, K.A.; Finkelstein, M.

1996-05-07

The invention relates to microorganisms which normally do not ferment a pentose sugar and which are genetically altered to ferment this pentose to produce ethanol. A representative example is Zymomonas mobilis which has been transformed with E. coli xylose isomerase, xylulokinase, transaldolase and transketolase genes. Expression of the added genes are under the control of Zymomonas mobilis promoters. This newly created microorganism is useful for fermenting pentoses and glucose, produced by hydrolysis of hemicellulose and cellulose, to produce ethanol. 2 figs.

Recombinant zymomonas for pentose fermentation

DOEpatents

Picataggio, Stephen K.; Zhang, Min; Eddy, Christina K.; Deanda, Kristine A.; Finkelstein, Mark

1996-01-01

The invention relates to microorganisms which normally do not ferment a pentose sugar and which are genetically altered to ferment this pentose to produce ethanol. A representative example is Zymomonas mobilis which has been transformed with E. coli xylose isomerase, xylulokinase, transaldolase and transketolase genes. Expression of the added genes are under the control of Zymomonas mobilis promoters. This newly created microorganism is useful for fermenting pentoses and glucose, produced by hydrolysis of hemicellulose and cellulose, to produce ethanol.

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.

Process for recovering hydrocarbons from hydrocarbon-containing biomass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dzadzic, P.M.; Price, M.C.; Shih, C.J.

1982-07-06

A process is disclosed for enzymatically converting whole plant biomass containing hydrocarbon-containing laticifers to soluble sugars and recovering hydrocarbons in increased yields. The process comprises hydrolyzing whole plant cellulosic material in the presence of enzymes, particularly cellulase, hemicellulase, and pectinase, to produce a hydrocarbon product and recovering from the hydrolysis products a major proportion of the cellulase, hemicellulase and pectinase enzymes for reuse. At least some portion of the required make-up of cellulase, hemicellulase and pectinase enzymes is produced in a two-stage operation wherein, in the first stage, a portion of the output sugar solution is used to grow enzymemore » secreting microorganisms selected from the group consisting of cellulase-secreting microorganisms, hemicellulase-secreting microorganisms, pectinase-secreting microorganisms, and mixtures thereof, and in the second stage, cellulase, hemicellulase and pectinase enzyme formation is induced in the microorganism-containing culture medium by the addition of an appropriate inducer such as biomass. The cellulase, hemicellulase and pectinase enzymes are then recycled for use in the hydrolysis reaction.« less

Identification of key micro-organisms involved in Douchi fermentation by statistical analysis and their use in an experimental fermentation.

PubMed

Chen, C; Xiang, J Y; Hu, W; Xie, Y B; Wang, T J; Cui, J W; Xu, Y; Liu, Z; Xiang, H; Xie, Q

2015-11-01

To screen and identify safe micro-organisms used during Douchi fermentation, and verify the feasibility of producing high-quality Douchi using these identified micro-organisms. PCR-denaturing gradient gel electrophoresis (DGGE) and automatic amino-acid analyser were used to investigate the microbial diversity and free amino acids (FAAs) content of 10 commercial Douchi samples. The correlations between microbial communities and FAAs were analysed by statistical analysis. Ten strains with significant positive correlation were identified. Then an experiment on Douchi fermentation by identified strains was carried out, and the nutritional composition in Douchi was analysed. Results showed that FAAs and relative content of isoflavone aglycones in verification Douchi samples were generally higher than those in commercial Douchi samples. Our study indicated that fungi, yeasts, Bacillus and lactic acid bacteria were the key players in Douchi fermentation, and with identified probiotic micro-organisms participating in fermentation, a higher quality Douchi product was produced. This is the first report to analyse and confirm the key micro-organisms during Douchi fermentation by statistical analysis. This work proves fermentation micro-organisms to be the key influencing factor of Douchi quality, and demonstrates the feasibility of fermenting Douchi using identified starter micro-organisms. © 2015 The Society for Applied Microbiology.

Production of gaba (γ – Aminobutyric acid) by microorganisms: a review

PubMed Central

Dhakal, Radhika; Bajpai, Vivek K.; Baek, Kwang-Hyun

2012-01-01

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. PMID:24031948

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.

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.

Photosynthetic approaches to chemical biotechnology.

PubMed

Desai, Shuchi H; Atsumi, Shota

2013-12-01

National interest and environmental advocates encourage alternatives to petroleum-based products. Besides biofuels, many other valuable chemicals used in every-day life are petroleum derivatives or require petroleum for their production. A plausible alternative to production using petroleum for chemical production is to harvest the abundant carbon dioxide resources in the environment to produce valuable hydrocarbons. Currently, efforts are being made to utilize a natural biological system, photosynthetic microorganisms, to perform this task. Photosynthetic microorganisms are attractive to use for biochemical production because they utilize economical resources for survival: sunlight and carbon dioxide. This review examines the various compounds produced by photosynthetic microorganisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

Microbial acetogenesis as a source of organic acids in ancient Atlantic Coastal Plain sediments

USGS Publications Warehouse

Chapelle, F.H.; Bradley, P.M.

1996-01-01

Field and laboratory evidence shows that deeply buried (90-888 m) fine-grained sediments of the Atlantic Coastal Plain contain viable acetogenic microorganisms, and that these microorganisms actively produce organic acids. Concentrations of formate, acetate, and propionate in pore waters extracted from fine-grained sediments ranged from 50 ??M to 5 mM and were much higher than in adjacent pore waters associated with sandy sediments (<2 ??M). Laboratory studies showed that asceptically cored fine-grained sediments incubated under a H2 atmosphere produced formate and acetate, and that H14CO-3 was converted to 14C-acetate and 14C-formate over time. An enrichment culture of these acetogenic microorganisms was recovered from one long-term incubation that showed the presence of several morphologically distinct gram-positive, rod-shaped bacteria. These microorganisms were capable of growth under autotrophic (H2 + CO2), heterotrophic (syringate), and mixotrophic (H2 + CO2 + syringate) conditions. These results suggest that microbial acetogenesis, rather than abiotic processes, is the most important organic acid-producing mechanism during low-temperature (???30 ??C) diagenesis of Atlantic Coastal Plain sediments.

Isolation, characterization, and diversity of novel radiotolerant carotenoid-producing bacteria.

PubMed

Asker, Dalal; Awad, Tarek S; Beppu, Teruhiko; Ueda, Kenji

2012-01-01

Carotenoids are natural pigments that exhibit many biological functions, such as antioxidants (i.e., promote oxidative stress resistance), membrane stabilizers, and precursors for vitamin A. The link between these biological activities and many health benefits (e.g., anticarcinogenic activity, prevention of chronic diseases, etc.) has raised the interest of several industrial sectors, especially in the cosmetics and pharmaceutical industries. The use of microorganisms in biotechnology to produce carotenoids is favorable by consumer and can help meet the growing demand for these bioactive compounds in the food, feed, and pharmaceutical industries. This methodological chapter details the development of a rapid and selective screening method for isolation and identification of carotenoid-producing microorganisms based on UV treatment, sequencing analysis of 16S rRNA genes, and carotenoids' analysis using rapid and effective High-Performance Liquid Chromatography-Diodearray-MS methods. The results of a comprehensive 16S rRNA gene-based phylogenetic analysis revealed a diversity of carotenoid-producing microorganisms (104 isolates) that were isolated at a high frequency from water samples collected at Misasa (Tottori, Japan), a region known for its high natural radioactivity content. These carotenoid-producing isolates were classified into 38 different species belonging to 7 bacterial classes (Flavobacteria, Sphingobacteria, α-Proteobacteria, γ-Proteobacteria, Deinococci, Actinobacteria, and Bacilli). The carotenoids produced by the isolates were zeaxanthin (6 strains), dihydroxyastaxanthin (24 strains), astaxanthin (27 strains), canthaxanthin (10 strains), and unidentified molecular species that were produced by the isolates related to Deinococcus, Exiguobacterium, and Flectobacillus. Here, we describe the methods used to isolate and classify these microorganisms.

Biological conversion of carbon dioxide and hydrogen into liquid fuels and industrial chemicals.

PubMed

Hawkins, Aaron S; McTernan, Patrick M; Lian, Hong; Kelly, Robert M; Adams, Michael W W

2013-06-01

Non-photosynthetic routes for biological fixation of carbon dioxide into valuable industrial chemical precursors and fuels are moving from concept to reality. The development of 'electrofuel'-producing microorganisms leverages techniques in synthetic biology, genetic and metabolic engineering, as well as systems-level multi-omic analysis, directed evolution, and in silico modeling. Electrofuel processes are being developed for a range of microorganisms and energy sources (e.g. hydrogen, formate, electricity) to produce a variety of target molecules (e.g. alcohols, terpenes, alkenes). This review examines the current landscape of electrofuel projects with a focus on hydrogen-utilizing organisms covering the biochemistry of hydrogenases and carbonic anhydrases, kinetic and energetic analyses of the known carbon fixation pathways, and the state of genetic systems for current and prospective electrofuel-producing microorganisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

Uric acid in plants and microorganisms: Biological applications and genetics - A review.

PubMed

Hafez, Rehab M; Abdel-Rahman, Tahany M; Naguib, Rasha M

2017-09-01

Uric acid increased accumulation and/or reduced excretion in human bodies is closely related to pathogenesis of gout and hyperuricemia. It is highly affected by the high intake of food rich in purine. Uric acid is present in both higher plants and microorganisms with species dependent concentration. Urate-degrading enzymes are found both in plants and microorganisms but the mechanisms by which plant degrade uric acid was found to be different among them. Higher plants produce various metabolites which could inhibit xanthine oxidase and xanthine oxidoreductase, so prohibit the oxidation of hypoxanthine to xanthine then to uric acid in the purine metabolism. However, microorganisms produce group of degrading enzymes uricase, allantoinase, allantoicase and urease, which catalyze the degradation of uric acid to the ammonia. In humans, researchers found that several mutations caused a pseudogenization (silencing) of the uricase gene in ancestral apes which exist as an insoluble crystalloid in peroxisomes. This is in contrast to microorganisms in which uricases are soluble and exist either in cytoplasm or peroxisomes. Moreover, many recombinant uricases with higher activity than the wild type uricases could be induced successfully in many microorganisms. The present review deals with the occurrence of uric acid in plants and other organisms specially microorganisms in addition to the mechanisms by which plant extracts, metabolites and enzymes could reduce uric acid in blood. The genetic and genes encoding for uric acid in plants and microorganisms are also presented.

Consolidated bioprocessing method using thermophilic microorganisms

DOEpatents

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.

Investigation of biosurfactant-producing indigenous microorganisms that enhance residue oil recovery in an oil reservoir after polymer flooding.

PubMed

She, Yue-Hui; Zhang, Fan; Xia, Jing-Jing; Kong, Shu-Qiong; Wang, Zheng-Liang; Shu, Fu-Chang; Hu, Ji-Ming

2011-01-01

Three biosurfactant-producing indigenous microorganisms (XDS1, XDS2, XDS3) were isolated from a petroleum reservoir in the Daqing Oilfield (China) after polymer flooding. Their metabolic, biochemical, and oil-degradation characteristics, as well as their oil displacement in the core were studied. These indigenous microorganisms were identified as short rod bacillus bacteria with white color, round shape, a protruding structure, and a rough surface. Strains have peritrichous flagella, are able to produce endospores, are sporangia, and are clearly swollen and terminal. Bacterial cultures show that the oil-spreading values of the fermentation fluid containing all three strains are more than 4.5 cm (diameter) with an approximate 25 mN/m surface tension. The hydrocarbon degradation rates of each of the three strains exceeded 50%, with the highest achieving 84%. Several oil recovery agents were produced following degradation. At the same time, the heavy components of crude oil were degraded into light components, and their flow characteristics were also improved. The surface tension and viscosity of the crude oil decreased after being treated by the three strains of microorganisms. The core-flooding tests showed that the incremental oil recoveries were 4.89-6.96%. Thus, XDS123 treatment may represent a viable method for microbial-enhanced oil recovery.

Continuing fascination of exploration in natural substances from microorganisms.

PubMed

Takahashi, Yoko

2017-01-01

In the search for novel organic compounds, I think it is of paramount importance not to overlook the pursuit of microorganism diversity and the abilities those microorganisms hold as a resource. In commemoration of Professor Satoshi Ōmura's Nobel Prize in Physiology or Medicine, I will briefly describe the microorganism that produces avermectin and then discuss how innovating isolation methods and pioneering isolation sources have opened the door to numerous new microorganism resources. Furthermore, as exploratory research of substances views the world from many different angles-from biological activity to a compound's physiochemical properties-it is possible to discover a novel compound from a well-known microorganism. Based on this, I will discuss the future prospects of exploratory research.

Bioremediation of Industrial Waste Through Enzyme Producing Marine Microorganisms.

PubMed

Sivaperumal, P; Kamala, K; Rajaram, R

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. © 2017 Elsevier Inc. All rights reserved.

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.

Molecular mechanisms of nematode-nematophagous microbe interactions: basis for biological control of plant-parasitic nematodes.

PubMed

Li, Juan; Zou, Chenggang; Xu, Jianping; Ji, Xinglai; Niu, Xuemei; Yang, Jinkui; Huang, Xiaowei; Zhang, Ke-Qin

2015-01-01

Plant-parasitic nematodes cause significant damage to a broad range of vegetables and agricultural crops throughout the world. As the natural enemies of nematodes, nematophagous microorganisms offer a promising approach to control the nematode pests. Some of these microorganisms produce traps to capture and kill the worms from the outside. Others act as internal parasites to produce toxins and virulence factors to kill the nematodes from within. Understanding the molecular basis of microbe-nematode interactions provides crucial insights for developing effective biological control agents against plant-parasitic nematodes. Here, we review recent advances in our understanding of the interactions between nematodes and nematophagous microorganisms, with a focus on the molecular mechanisms by which nematophagous microorganisms infect nematodes and on the nematode defense against pathogenic attacks. We conclude by discussing several key areas for future research and development, including potential approaches to apply our recent understandings to develop effective biocontrol strategies.

Toolbox for Antibiotics Discovery from Microorganisms.

PubMed

Fisch, Katja M; Schäberle, Till F

2016-09-01

Microorganisms produce a vast array of biologically active metabolites. Such compounds are applied by humans to positively influence their health and, therefore, natural products serve as drug leads for pharmaceutical and medicinal chemistry. In this minireview, tools for the discovery and the production of potential drug leads are explained. A snapshot is provided, starting from the isolation of new producer strains, across genomic mining of (meta)genomes to identify biosynthetic gene clusters corresponding to natural products, toward heterologous expression to produce potential drug leads. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recombinant Zymomonas for pentose fermentation

DOEpatents

Picataggio, S.K.; Min Zhang; Eddy, C.K.; Deanda, K.A.

1998-03-10

The invention relates to microorganisms which normally do not ferment pentose sugar and which are genetically altered to ferment pentose sugar to produce ethanol, and fermentation processes utilizing the same. Examples include Zymomonas mobilis which has been transformed with combinations of E. coli genes for xylose isomerase, xylulokinase, transaldolase, transketolase, L-arabinose isomerase, L-ribulokinase, and L-ribulose-5-phosphate 4-epimerase. Expression of the added genes are under the control of Zymomonas mobilis promoters. These newly created microorganisms are useful for fermenting pentoses and glucose, produced by hydrolysis of hemicellulose and cellulose, to produce ethanol. 7 figs.

Pentose fermentation by recombinant Zymomonas

DOEpatents

Picataggio, S.K.; Zhang, M.; Eddy, C.K.; Deanda, K.A.; Finkelstein, M.; Mohagheghi, A.; Newman, M.M.; McMillan, J.D.

1998-01-27

The invention relates to microorganisms which normally do not ferment pentose sugar and which are genetically altered to ferment pentose sugar to produce ethanol, and fermentation processes utilizing the same. Examples include Zymomonas mobilis which has been transformed with combinations of E. coli genes for xylose isomerase, xylulokinase, transaldolase, transketolase, L-arabinose isomerase, L-ribulokinase, and L-ribulose 5-phosphate 4-epimerase. Expression of the added genes are under the control of Zymomonas mobilis promoters. These newly created microorganisms are useful for fermenting pentoses and glucose, produced by hydrolysis of hemicellulose and cellulose, to produce ethanol. 7 figs.

Pentose fermentation by recombinant zymomonas

DOEpatents

Picataggio, Stephen K.; Zhang, Min; Eddy, Christina K.; Deanda, Kristine A.; Finkelstein, Mark; Mohagheghi, Ali; Newman, Mildred M.; McMillan, James D.

1998-01-01

The invention relates to microorganisms which normally do not ferment pentose sugar and which are genetically altered to ferment pentose sugar to produce ethanol, and fermentation processes utilizing the same. Examples include Zymomonas mobilis which has been transformed with combinations of E. coli genes for xylose isomerase, xylulokinase, transaldolase, transketolase, L-arabinose isomerase, L-ribulokinase, and L-ribulose 5-phosphate 4-epimerase. Expression of the added genes are under the control of Zymomonas mobilis promoters. These newly created microorganisms are useful for fermenting pentoses and glucose, produced by hydrolysis of hemicellulose and cellulose, to produce ethanol.

Recombinant Zymomonas for pentose fermentation

DOEpatents

Picataggio, Stephen K.; Zhang, Min; Eddy, Christina K.; Deanda, Kristine A.

1998-01-01

The invention relates to microorganisms which normally do not ferment pentose sugar and which are genetically altered to ferment pentose sugar to produce ethanol, and fermentation processes utilizing the same. Examples include Zymomonas mobilis which has been transformed with combinations of E. coli genes for xylose isomerase, xylulokinase, transaldolase, transketolase, L-arabinose isomerase, L-ribulokinase, and L-ribulose-5-phosphate 4-epimerase. Expression of the added genes are under the control of Zymomonas mobilis promoters. These newly created microorganisms are useful for fermenting pentoses and glucose, produced by hydrolysis of hemicellulose and cellulose, to produce ethanol.

Engineering of thermotolerant Bacillus coagulans for production of D(-)-lactic acid

DOEpatents

Wang, Qingzhao; Shanmugam, Keelnatham T; Ingram, Lonnie O

2014-12-02

Genetically modified microorganisms having the ability to produce D(-)-lactic acid at temperatures between 30.degree. C. and 55.degree. C. are provided. In various embodiments, the microorganisms may have the chromosomal lactate dehydrogenase (ldh) gene and/or the chromosomal acetolactate synthase (alsS) gene inactivated. Exemplary microorganisms for use in the disclosed methods are Bacillus spp., such as Bacillus coagulans.

Novel technologies provide more engineering strategies for amino acid-producing microorganisms.

PubMed

Gu, Pengfei; Su, Tianyuan; Qi, Qingsheng

2016-03-01

Traditionally, amino acid-producing strains were obtained by random mutagenesis and subsequent selection. With the development of genetic and metabolic engineering techniques, various microorganisms with high amino acid production yields are now constructed by rational design of targeted biosynthetic pathways. Recently, novel technologies derived from systems and synthetic biology have emerged and open a new promising avenue towards the engineering of amino acid production microorganisms. In this review, these approaches, including rational engineering of rate-limiting enzymes, real-time sensing of end-products, pathway optimization on the chromosome, transcription factor-mediated strain improvement, and metabolic modeling and flux analysis, were summarized with regard to their application in microbial amino acid production.

Aquatic Plant Control Research Program. Biological Control of Hydrilla verticillata (L.f.) Royle with Lytic Enzyme-Producing Microorganisms.

DTIC Science & Technology

1985-09-01

pectinase . Lytic enzyme-positive isolates were successively subcultured on restrictive media in the laboratory to enhance enzyme production. Twenty-two...candidate microorganisms by testing isolates for produc- tion of cellulase and pectinase . c. Taxonomically characterize candidates. d. Enhance production of...present study, but could become necessary if results of this study indicate that cellulase-enhanced v ,isolates are capable of damaging hydrilla. Pectinase

Effect of Contamination with Perennial Permafrost Microorganisms on the Outcome of Closed Brain Neurotrauma.

PubMed

Malchevskii, V A; Subbotin, A M; Nemkov, A G; Petrov, S A

2016-07-01

We studied the effect of contamination with Bacillus genus microorganisms isolated from perennial permafrost samples on the outcome of closed brain neurotrauma in Wistar rats. It was found that contamination with different Bacillus strains produced different effects on the mortality of experimental animals with closed neurotrauma. The complex of metabolites from strain Ch2/9 - Bacillus spp. (pumilus) produced a protective effect in experimental closed brain neurotrauma.

The relationship between the structures of four beta-lactamases obtained from Bacillus cereus.

PubMed

Cid, H; Carrillo, O; Bunster, M; Martínez, J; Vargas, V

1988-06-01

Bacillus cereus has proved to be one of the most interesting microorganisms in the study of beta-lactamases. It secrets these enzymes very efficiently and, frequently, in multiple forms. Three different forms are produced by strain 569/H; mutant 5/B of the same microorganism is constitutive for the secretion of beta-lactamases I and II. The present study, based on secondary structure prediction by two independent methods, states the relationship among the structures of beta-lactamases I, II and III produced by B. cereus 569/H and beta-lactamase I from the strain 5/B of this microorganism. A strong similarity is also established for the enzyme type III of B. cereus and the enzyme type I produced by B. licheniformis which could have an evolutionary explanation. A structural analysis of the leader peptide regions of these enzymes by the method of Mohana and Argos is also reported.

Production of butanol by fermentation in the presence of cocultures of clostridium

NASA Technical Reports Server (NTRS)

Bergstrom, S. L.; Foutch, G. L. (Inventor)

1985-01-01

Sugars are converted to a mixture of solvents including butanol by a fermentation process employing a coculture of microorganisms of the Clostridium genus, one of said microorganisms favoring the production of butyric acid and the other of which converts the butyric acid so produced to butanol. The use of a coculture substantially increases the yield of butanol over that obtained using a culture employing only one microorganism.

Anti-Candida and anti-Cryptococcus antifungal produced by marine microorganisms.

PubMed

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

2014-12-01

In order to search for antifungal from biological origin, we performed a screening of marine microorganisms isolated from seawater, seaweed, sediment and marine invertebrates collected from different coastal areas of the Moroccan Atlantic Ocean. The antifungal activities of these isolates were investigated against the pathogenic yeasts involved in medical mycology. Whole cultures of 34 marine microorganisms were screened for antifungal activities using the method of agar diffusion against four yeasts. The results showed that among the 34 isolates studied, 13 (38%) strains have antifungal activity against at least one out of four yeast species, 11 isolates have anti-Candida albicans CIP 48.72 activity, 12 isolates have anti-C. albicans CIP 884.65 activity, 13 isolates have anti-Cryptococcus neoformans activity and only 6 isolates are actives against Candida tropicalis R2 resistant to nystatin and amphotericin B. Nine isolates showed strong fungicidal activity. Fourteen microorganisms were identified and 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 could produce more antimicrobials; therefore these marine microorganisms were expected to be potential resources of natural products such as those we research: anti-Candida and anti-Cryptococcus fungicides. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Screening For Alcohol-Producing Microbes

NASA Technical Reports Server (NTRS)

Schubert, Wayne W.

1988-01-01

Dye reaction rapidly identifies alcohol-producing microbial colonies. Method visually detects alcohol-producing micro-organisms, and distinguishes them from other microbial colonies that do not produce alcohol. Method useful for screening mixed microbial populations in environmental samples.

Streptomyces metabolites in divergent microbial interactions.

PubMed

Takano, Hideaki; Nishiyama, Tatsuya; Amano, Sho-ichi; Beppu, Teruhiko; Kobayashi, Michihiko; Ueda, Kenji

2016-03-01

Streptomyces and related bacteria produce a wide variety of secondary metabolites. Of these, many compounds have industrial applications, but the question of why this group of microorganism produces such various kinds of biologically active substances has not yet been clearly answered. Here, we overview the results from our studies on the novel function and role of Streptomyces metabolites. The diverged action of negative and positive influences onto the physiology of various microorganisms infers the occurrence of complex microbial interactions due to the effect of small molecules produced by Streptomyces. The interactions may serve as a basis for the constitution of biological community.

Biosynthesis of human diazepam and clonazepam metabolites.

PubMed

de Paula, Núbia C; Araujo Cordeiro, Kelly C F; de Melo Souza, Paula L; Nogueira, Diogo F; da Silva e Sousa, Diego B; Costa, Maísa B; Noël, François; de Oliveira, Valéria

2015-03-01

A screening of fungal and microbial strains allowed to select the best microorganisms to produce in high yields some of the human metabolites of two benzodiazepine drugs, diazepam and clonazepam, in order to study new pharmacological activities and for chemical standard proposes. Among the microorganisms tested, Cunninghamella echinulata ATCC 9244 and Rhizopus arrhizus ATCC 11145 strains, were the most active producers of the mains metabolites of diazepam which included demethylated, hydroxylated derivatives. Beauveria bassiana ATCC 7159 and Chaetomium indicum LCP 984200 produced the 7 amino-clonazepam metabolite and a product of acid hydrolysis of this benzodiazepine. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthetic extreme environments: overlooked sources of potential biotechnologically relevant microorganisms.

PubMed

Sibanda, Timothy; Selvarajan, Ramganesh; Tekere, Memory

2017-05-01

Synthetic extreme environments like carwash effluent tanks and drains are potential sources of biotechnologically important microorganisms and molecules which have, however, remained unexplored. Using culture- and molecular-based methods, a total of 17 bacterial isolates belonging to the genera Shewanella, Proteus, Paenibacillus, Enterobacter and Citrobacter, Aeromonas, Pseudomonas and Pantoea were identified. Hydrocarbon utilization and enzyme production screening assays showed that Aeromonas sp. CAC11, Paenibacillus sp. CAC12 and Paenibacillus sp. CAC13 and Citrobacter sp. PCW7 were able to degrade benzanthracene, naphthalene and diesel oil, Paenibacillus sp. CAC12 and Paenibacillus sp. CAC13 could produce cellulase enzyme, while Proteus sp. BPS2, Pseudomonas sp. SAS8 and Proteus sp. CAL3 could produce lipase. GC-MS analysis of bacterial secondary metabolites resulted in identification of 107 different compounds produced by Proteus sp. BPS2, Paenibacillus sp. CAC12, Pseudomonas sp. SAS8, Proteus sp. CAL3 and Paenibacillus sp. CAC13. Most of the compounds identified by both GC-MS and LC-MS have previously been determined to have antibacterial, antifungal and/or anticancer properties. Further, microbial metabolites which have previously been known to be produced only by plants or microorganisms found in natural extreme environments were also identified in this study. This research has revealed the immense bioresource potential of microorganisms inhabiting synthetic extreme environments. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Simple, effective protein extraction method and proteomics analysis from polyunsaturated fatty acids-producing micro-organisms.

PubMed

Ling, Xueping; Guo, Jing; Zheng, Chuqiang; Ye, Chiming; Lu, Yinghua; Pan, Xueshan; Chen, Zhengqi; Ng, I-Son

2015-12-01

Polyunsaturated fatty acids (PUFAs) are valuable ingredients in the food and pharmaceutical products due to their beneficial influence on human health. Most studies paid attention on the production of PUFAs from oleaginous micro-organisms but seldom on the comparative proteomics of cells. In the study, three methods (i.e., cold shock, acetone precipitation and ethanol precipitation) for lipid removal from crude protein extracts were applied in different PUFAs-producing micro-organisms. Among the selective strains, Schizochytrium was used as an oleaginous strain with high lipid of 60.3 (w/w%) in biomass. The Mortierella alpina and Cunninghamella echinulata were chosen as the low-lipid-content strains with 25.8 (w/w%) and 21.8 (w/w%) of lipid in biomass, respectively. The cold shock resulted as the most effective method for lipid removed, thus obtained higher protein amount for Schizochytrium. Moreover, from the comparative proteomics for the three PUFAs-producing strains, it showed more significant proteins of up or down-regulation were explored under cold shock treatment. Therefore, the essential proteins (i.e., polyunsaturated fatty acid synthase) and regulating proteins were observed. In conclusion, this study provides a valuable and practical approach for analysis of high PUFAs-producing strains at the proteomics level, and would further accelerate the understanding of the metabolic flux in oleaginous micro-organisms.

Metabolic Engineering for Advanced Biofuels Production and Recent Advances Toward Commercialization

DOE PAGES

Meadows, Corey W.; Kang, Aram; Lee, Taek S.

2017-07-21

Research on renewable biofuels produced by microorganisms has enjoyed considerable advances in academic and industrial settings. As the renewable ethanol market approaches maturity, the demand is rising for the commercialization of more energy-dense fuel targets. Many strategies implemented in recent years have considerably increased the diversity and number of fuel targets that can be produced by microorganisms. Moreover, strain optimization for some of these fuel targets has ultimately led to their production at industrial scale. In this review, we discuss recent metabolic engineering approaches for augmenting biofuel production derived from alcohols, isoprenoids, and fatty acids in several microorganisms. In addition,more » we discuss successful commercialization ventures for each class of biofuel targets.« less

Metabolic Engineering for Advanced Biofuels Production and Recent Advances Toward Commercialization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meadows, Corey W.; Kang, Aram; Lee, Taek S.

Research on renewable biofuels produced by microorganisms has enjoyed considerable advances in academic and industrial settings. As the renewable ethanol market approaches maturity, the demand is rising for the commercialization of more energy-dense fuel targets. Many strategies implemented in recent years have considerably increased the diversity and number of fuel targets that can be produced by microorganisms. Moreover, strain optimization for some of these fuel targets has ultimately led to their production at industrial scale. In this review, we discuss recent metabolic engineering approaches for augmenting biofuel production derived from alcohols, isoprenoids, and fatty acids in several microorganisms. In addition,more » we discuss successful commercialization ventures for each class of biofuel targets.« less

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 environment/organisms for the production of desired sugar and lipid end-products.

Antagonistic potential against pathogenic microorganisms and hydrogen peroxide production of indigenous lactobacilli isolated from vagina of Chinese pregnant women.

PubMed

Xu, Heng-Yi; Tian, Wan-Hong; Wan, Cui-Xiang; Jia, Li-Jun; Wang, Lan-Yin; Yuan, Jing; Liu, Chun-Mei; Zeng, Ming; Wei, Hua

2008-10-01

To investigate the indigenous lactobacilli from the vagina of pregnant women and to screen the isolates with antagonistic potential against pathogenic microorganisms. The strains were isolated from pregnant women's vagina and identified using the API50CH system. The ability of the isolates to produce hydrogen peroxide was analyzed semi-quantitatively using the TMB-HRP-MRS agar. The antagonistic effects of the isolates on pathogenic microorganisms were determined with a double layer agar plate. One hundred and three lactobacilli strains were isolated from 60 samples of vaginal secretion from healthy pregnant women. Among them, 78 strains could produce hydrogen peroxide, in which 68%, 80%, 80%, and 88% had antagonistic effects against Candida albicans CMCC98001, Staphylococcus aureus CMCC26003, Escherichia coli CMCC44113, and Pseudomonas aeruginosa CMCC10110, respectively. The recovery of hydrogen peroxide-producing lactobacilli decreases with the increasing pregnant age and time. The most commonly isolated species from vagina of Chinese pregnant women are Lactobacillus acidophilus and Lactobacillus crispatus. Most of L. acidophilus and L. crispatus produce a high H2O2 level.

21 CFR 173.145 - Alpha-Galactosidase derived from Mortierella vinaceae var. raffinoseutilizer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.145 Alpha-Galactosidase derived from... following conditions: (a) The food additive is the enzyme alpha-galactosidase and the mycelia of the microorganism Mortierella vinaceae var. raffinoseutilizer which produces the enzyme. (b) The nonpathogenic...

Construction Biotechnology: a new area of biotechnological research and applications.

PubMed

Stabnikov, Viktor; Ivanov, Volodymyr; Chu, Jian

2015-09-01

A new scientific and engineering discipline, Construction Biotechnology, is developing exponentially during the last decade. The major directions of this discipline are selection of microorganisms and development of the microbially-mediated construction processes and biotechnologies for the production of construction biomaterials. The products of construction biotechnologies are low cost, sustainable, and environmentally friendly microbial biocements and biogrouts for the construction ground improvement. The microbial polysaccharides are used as admixtures for cement. Microbially produced biodegradable bioplastics can be used for the temporarily constructions. The bioagents that are used in construction biotechnologies are either pure or enrichment cultures of microorganisms or activated indigenous microorganisms of soil. The applications of microorganisms in the construction processes are bioaggregation, biocementation, bioclogging, and biodesaturation of soil. The biotechnologically produced construction materials and the microbially-mediated construction technologies have a lot of advantages in comparison with the conventional construction materials and processes. Proper practical implementations of construction biotechnologies could give significant economic and environmental benefits.

Attempt to simultaneously generate three chiral centers in 4-hydroxyisoleucine with microbial carbonyl reductases.

PubMed

Hibi, Makoto; Takahashi, Koji; Kako, Junko; Wakita, Yuuta; Kodera, Tomohiro; Shimizu, Sakayu; Yokozeki, Kenzo; Ogawa, Jun

2018-04-01

A panel of microorganisms was screened for selective reduction ability towards a racemic mixture of prochiral 2-amino-3-methyl-4-ketopentanoate (rac-AMKP). Several of the microorganisms tested produced greater than 0.5mM 4-hydroxyisoleucine (HIL) from rac-AMKP, and the stereoselectivity of HIL formation was found to depend on the taxonomic category to which the microorganism belonged. The enzymes responsible for the AMKP-reducing activity, ApAR and FsAR, were identified from two of these microorganisms, Aureobasidium pullulans NBRC 4466 and Fusarium solani TG-2, respectively. Three AMKP reducing enzymes, ApAR, FsAR, and the previously reported BtHILDH, were reacted with rac-AMKP, and each enzyme selectively produced a specific composition of HIL stereoisomers. The enzymes appeared to have different characteristics in recognition of the stereostructure of the substrate AMKP and in control of the 4-hydroxyl group configuration in the HIL product. Copyright © 2017 Elsevier Ltd. All rights reserved.

Secondary metabolites from marine microorganisms.

PubMed

Kelecom, Alphonse

2002-03-01

After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

Microbial dynamics in petroleum oilfields and their relationship with physiological properties of petroleum oil reservoirs.

PubMed

Varjani, Sunita J; Gnansounou, Edgard

2017-12-01

Petroleum is produced by thermal decay of buried organic material over millions of years. Petroleum oilfield ecosystems represent resource of reduced carbon which favours microbial growth. Therefore, it is obvious that many microorganisms have adapted to harsh environmental conditions of these ecosystems specifically temperature, oxygen availability and pressure. Knowledge of microorganisms present in ecosystems of petroleum oil reservoirs; their physiological and biological properties help in successful exploration of petroleum. Understanding microbiology of petroleum oilfield(s) can be used to enhance oil recovery, as microorganisms in oil reservoirs produce various metabolites viz. gases, acids, solvents, biopolymers and biosurfactants. The aim of this review is to discuss characteristics of petroleum oil reservoirs. This review also provides an updated literature on microbial ecology of these extreme ecosystems including microbial origin as well as various types of microorganisms such as methanogens; iron, nitrate and sulphate reducing bacteria, and fermentative microbes present in petroleum oilfield ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

A multi-criteria analysis approach for ranking and selection of microorganisms for the production of oils for biodiesel production.

PubMed

Ahmad, Farah B; Zhang, Zhanying; Doherty, William O S; O'Hara, Ian M

2015-08-01

Oleaginous microorganisms have potential to be used to produce oils as alternative feedstock for biodiesel production. Microalgae (Chlorella protothecoides and Chlorella zofingiensis), yeasts (Cryptococcus albidus and Rhodotorula mucilaginosa), and fungi (Aspergillus oryzae and Mucor plumbeus) were investigated for their ability to produce oil from glucose, xylose and glycerol. Multi-criteria analysis (MCA) using analytic hierarchy process (AHP) and preference ranking organization method for the enrichment of evaluations (PROMETHEE) with graphical analysis for interactive aid (GAIA), was used to rank and select the preferred microorganisms for oil production for biodiesel application. This was based on a number of criteria viz., oil concentration, content, production rate and yield, substrate consumption rate, fatty acids composition, biomass harvesting and nutrient costs. PROMETHEE selected A. oryzae, M. plumbeus and R. mucilaginosa as the most prospective species for oil production. However, further analysis by GAIA Webs identified A. oryzae and M. plumbeus as the best performing microorganisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Algicidal microorganisms and secreted algicides: New tools to induce microalgal cell disruption.

PubMed

Demuez, Marie; González-Fernández, Cristina; Ballesteros, Mercedes

2015-12-01

Cell disruption is one of the most critical steps affecting the economy and yields of biotechnological processes for producing biofuels from microalgae. Enzymatic cell disruption has shown competitive results compared to mechanical or chemical methods. However, the addition of enzymes implies an associated cost in the overall production process. Recent studies have employed algicidal microorganisms to perform enzymatic cell disruption and degradation of microalgae biomass in order to reduce this associated cost. Algicidal microorganisms induce microalgae growth inhibition, death and subsequent lysis. Secreted algicidal molecules and enzymes produced by bacteria, cyanobacteria, viruses and the microalga themselves that are capable of inducing algal death are classified, and the known modes of action are described along with insights into cell-to-cell interaction and communication. This review aims to provide information regarding microalgae degradation by microorganisms and secreted algicidal substances that would be useful for microalgae cell breakdown in biofuels production processes. A better understanding of algae-to-algae communication and the specific mechanisms of algal cell lysis is expected to be an important breakthrough for the broader application of algicidal microorganisms in biological cell disruption and the production of biofuels from microalgae biomass. Copyright © 2015 Elsevier Inc. All rights reserved.

Microorganisms having enhanced tolerance to inhibitors and stress

DOEpatents

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.

A FIELD STUDY WITH GENETICALLY ENGINEERED ALFALFA INOCULATED WITH RECOMBINANT SINORHIZOBIUM MELILOTI: EFFECTS ON THE SOIL ECOSYSTEM

EPA Science Inventory

The agricultural use of genetically engineered plants and microorganisms has become increasingly common. Because genetically engineered plants and microorganisms can produce compounds foreign to their environment, there is concern that they may become established outside of thei...

Biologically Active Metabolites Synthesized by Microalgae

PubMed Central

Costa, Jorge Alberto Vieira

2015-01-01

Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences. PMID:26339647

Single Zymomonas mobilis strain for xylose and arabinose fermentation

DOEpatents

Zhang, M.; Chou, Y.C.; Picataggio, S.K.; Finkelstein, M.

1998-12-01

This invention relates to single microorganisms which normally do not ferment pentose sugars which are genetically altered to ferment the pentose sugars, xylose and arabinose, to produce ethanol, and a fermentation process utilizing the same. Examples include Zymomonas mobilis which has been transformed with a combination of E. coli genes for xylose isomerase, xylulokinase, L-arabinose isomerase, L-ribulokinase, L-ribulose 5-phosphate 4-epimerase, transaldolase and transketolase. Expression of added genes are under the control of Z. mobilis promoters. These newly created microorganisms are useful for fermenting glucose, xylose and arabinose, produced by hydrolysis of hemicellulose and cellulose or starch, to produce ethanol. 6 figs.

Single zymomonas mobilis strain for xylose and arabinose fermentation

DOEpatents

Zhang, Min; Chou, Yat-Chen; Picataggio, Stephen K.; Finkelstein, Mark

1998-01-01

This invention relates to single microorganisms which normally do not ferment pentose sugars which are genetically altered to ferment the pentose sugars, xylose and arabinose, to produce ethanol, and a fermentation process utilizing the same. Examples include Zymomonas mobilis which has been transformed with a combination of E. coli genes for xylose isomerase, xylulokinase, L-arabinose isomerase, L-ribulokinase, L-ribulose 5-phosphate 4-epimerase, transaldolase and transketolase. Expression of added genes are under the control of Z. mobilis promoters. These newly created microorganisms are useful for fermenting glucose, xylose and arabinose, produced by hydrolysis of hemicellulose and cellulose or starch, to produce ethanol.

Prevalence of extended-spectrum beta-lactamases-producing microorganisms in nosocomial patients and molecular characterization of the shv type isolates

PubMed Central

de Oliveira, Caio Fernando; Salla, Adenilde; Lara, Valéria Maria; Rieger, Alexandre; Horta, Jorge André; Alves, Sydney Hartz

2010-01-01

The emergence of Extended-Spectrum Beta-Lactamase (ESBL)-producing microorganisms in Brazilian hospitals is a challenge that concerns scientists, clinicians and healthcare institutions due to the serious risk they pose to confined patients. The goal of this study was the detection of ESBL production by clinical strains of Escherichia coli and Klebsiella sp. isolated from pus, urine and blood of patients at Hospital Universitário Santa Maria, Rio Grande Sul, RS, Brazil and the genotyping of the isolates based on bla SHV genes. The ESBL study was carried out using the Combined Disc Method, while Polymerase Chain Reaction (PCR) was used to study the bla SHV genes. Of the 90 tested isolates, 55 (61.1%) were identified as ESBL-producing by the combined disk method. The bla SHV genes were found in 67.8% of these microorganisms. K. pneumoniae predominated in the samples, presenting the highest frequency of positive results from the combined disk and PCR. PMID:24031491

Identification and analysis of the bacterial endosymbiont specialized for production of the chemotherapeutic natural product ET-743

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schofield, Michael M.; Jain, Sunit; Porat, Daphne

Ecteinascidin 743 (ET-743, Yondelis) is a clinically approved chemotherapeutic natural product isolated from the Caribbean mangrove tunicate Ecteinascidia turbinata. Researchers have long suspected that a microorganism may be the true producer of the anti-cancer drug, but its genome has remained elusive due to our inability to culture the bacterium in the laboratory using standard techniques. Here, we sequenced and assembled the complete genome of the ET-743 producer, Candidatus Endoecteinascidia frumentensis, directly from metagenomic DNA isolated from the tunicate. Analysis of the ~631 kb microbial genome revealed strong evidence of an endosymbiotic lifestyle and extreme genome reduction. Phylogenetic analysis suggested thatmore » the producer of the anti-cancer drug is taxonomically distinct from other sequenced microorganisms and could represent a new family of Gammaproteobacteria. The complete genome has also greatly expanded our understanding of ET-743 production and revealed new biosynthetic genes dispersed across more than 173 kb of the small genome. The gene cluster’s architecture and its preservation demonstrate that the drug is likely essential to the interactions of the microorganism with its mangrove tunicate host. In conclusion, taken together, these studies elucidate the lifestyle of a unique, and pharmaceutically-important microorganism and highlight the wide diversity of bacteria capable of making potent natural products.« less

Identification and analysis of the bacterial endosymbiont specialized for production of the chemotherapeutic natural product ET-743

DOE PAGES

Schofield, Michael M.; Jain, Sunit; Porat, Daphne; ...

2015-07-21

Ecteinascidin 743 (ET-743, Yondelis) is a clinically approved chemotherapeutic natural product isolated from the Caribbean mangrove tunicate Ecteinascidia turbinata. Researchers have long suspected that a microorganism may be the true producer of the anti-cancer drug, but its genome has remained elusive due to our inability to culture the bacterium in the laboratory using standard techniques. Here, we sequenced and assembled the complete genome of the ET-743 producer, Candidatus Endoecteinascidia frumentensis, directly from metagenomic DNA isolated from the tunicate. Analysis of the ~631 kb microbial genome revealed strong evidence of an endosymbiotic lifestyle and extreme genome reduction. Phylogenetic analysis suggested thatmore » the producer of the anti-cancer drug is taxonomically distinct from other sequenced microorganisms and could represent a new family of Gammaproteobacteria. The complete genome has also greatly expanded our understanding of ET-743 production and revealed new biosynthetic genes dispersed across more than 173 kb of the small genome. The gene cluster’s architecture and its preservation demonstrate that the drug is likely essential to the interactions of the microorganism with its mangrove tunicate host. In conclusion, taken together, these studies elucidate the lifestyle of a unique, and pharmaceutically-important microorganism and highlight the wide diversity of bacteria capable of making potent natural products.« less

Aspects of tests and assessment of filtering materials used for respiratory protection against bioaerosols. Part I: type of active substance, contact time, microorganism species.

PubMed

Majchrzycka, Katarzyna; Gutarowska, Beata; Brochocka, Agnieszka

2010-01-01

This paper presents the results of a study on antimicrobial activity of polymer filter nonwovens produced by needle-punching or melt-blowing with an addition of disinfecting agents. The first part of the paper discusses how the biocidal activity of nonwovens is a function of the active agent added to the nonwovens, the duration of the contact of microorganisms with nonwovens and the type of microorganisms. The types of fibres and disinfecting agents had a considerable effect on the biocidal activity of nonwovens. The biocidal effect of nonwovens increased with the duration of their contact with microorganisms. Fibre activity differed considerably depending on the species of the microorganism. The microorganisms most sensitive to biocidal activity of the active filter nonwoven were S. aureus, M. flavus and E. coli. There were no biocidal effects on spore-forming bacterium B. subtilis.

In situ antimicrobial behavior of materials with copper-based additives in a hospital environment.

PubMed

Palza, Humberto; Nuñez, Mauricio; Bastías, Roberto; Delgado, Katherine

2018-06-01

Copper and its alloys are effective antimicrobial surface materials in the laboratory and in clinical trials. Copper has been used in the healthcare setting to reduce environmental contamination, and thus prevent healthcare-associated infections, complementing traditional protocols. The addition of copper nanoparticles to polymer/plastic matrices can also produce antimicrobial materials, as confirmed under laboratory conditions. However, there is a lack of studies validating the antimicrobial effects of these nanocomposite materials in clinical trials. To satisfy this issue, plastic waiting room chairs with embedded metal copper nanoparticles, and metal hospital IV pools coated with an organic paint with nanostructured zeolite/copper particles were produced and tested in a hospital environment. These prototypes were sampled once weekly for 10 weeks and the viable microorganisms were analysed and compared with the copper-free materials. In the waiting rooms, chairs with copper reduced by around 73% the total viable microorganisms present, showing activity regardless of the microorganism tested. Although there were only low levels of microorganisms in the IV pools installed in operating rooms because of rigorous hygiene protocols, samples with copper presented lower total viable microorganisms than unfilled materials. Some results did not have statistical significance because of the low load of microorganisms; however, during at least three weeks the IV pools with copper had reduced levels of microorganisms by a statistically significant 50%. These findings show for the first time the feasibility of utilizing the antimicrobial property of copper by adding nanosized fillers to other materials in a hospital environment. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Concentrations of airborne endotoxin and microorganisms at a 10,000 cow open-freestall dairy

USDA-ARS?s Scientific Manuscript database

Confined animal production systems produce elevated bioaerosol concentrations, which are a potential respiratory health risk to individuals on site and downwind. In this study, airborne endotoxin and microorganisms were collected during the spring, summer, and fall at a large open-freestall dairy i...

Bacteria engineered for fuel ethanol production: current status

Treesearch

B.S. Dien; M.A. Cotta; T.W. Jeffries

2003-01-01

The lack of industrially suitable microorganisms for converting biomass into fuel ethanol has traditionally been cited as a major technical roadblock to developing a bioethanol industry. In the last two decades, numerous microorganisms have been engineered to selectively produce ethanol. Lignocellulosic biomass contains complex carbohydrates that necessitate utilizing...

Biohydrogenesis in the Thermotogales

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, Robert M.; Blum, Paul H.; Noll, Kenneth M.

The production and consumption of molecular hydrogen drives the physiology and bioenergetics of many microorganisms in hydrothermal environments. As such, the potential of these microorganisms as model systems to probe fundamental issues related to biohydrogen production merits consideration. It is important to understand how carbon/energy sources relate to the disposition of reducing power and, ultimately, the formation of molecular hydrogen by high temperature microorganisms. This project focused on bacteria in the thermophilic order Thermotogales, fermentative anaerobes that produce H 2 from simple and complex carbohydrates.

Degradation of microbial polyesters.

PubMed

Tokiwa, Yutaka; Calabia, Buenaventurada P

2004-08-01

Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.

21 CFR 186.1275 - Dextrans.

Code of Federal Regulations, 2010 CFR

2010-04-01

... weight polysaccharides produced by bacterial fermentation of sucrose. Commercially available dextrans are... purification of the fermented mixture shall produce a product that is free of viable microorganisms. (b) The...

21 CFR 186.1275 - Dextrans.

Code of Federal Regulations, 2013 CFR

2013-04-01

... weight polysaccharides produced by bacterial fermentation of sucrose. Commercially available dextrans are... purification of the fermented mixture shall produce a product that is free of viable microorganisms. (b) The...

21 CFR 186.1275 - Dextrans.

Code of Federal Regulations, 2012 CFR

2012-04-01

... weight polysaccharides produced by bacterial fermentation of sucrose. Commercially available dextrans are... purification of the fermented mixture shall produce a product that is free of viable microorganisms. (b) The...

21 CFR 186.1275 - Dextrans.

Code of Federal Regulations, 2011 CFR

2011-04-01

... weight polysaccharides produced by bacterial fermentation of sucrose. Commercially available dextrans are... purification of the fermented mixture shall produce a product that is free of viable microorganisms. (b) The...

Nonthermal Biological Treatments Using Discharge Plasma Produced by Pulsed Power 4. Cleaning of Lakes and Marshes by Pulsed Power Produced Streamer Discharges in Water

NASA Astrophysics Data System (ADS)

Akiyama, Hidenori; Katsuki, Sunao; Namihira, Takao; Ishibashi, Kazuo; Kiyosaki, Noriaki

Pulsed power has been used to produce non-thermal plasmas in atmospheric pressure gases that generate a high electric field at the tips of streamer discharges, where high energy electrons, free radicals, ultraviolet rays, and ozone are produced. These manifestations of streamer discharges have been used in the treatment of exhaust gases, removal of volatile and toxic compounds such as dioxin, and the sterilization of microorganisms. Here, large volume streamer discharges in water are described. These streamer discharges in liquids are able to produce a high electric field, high energy electrons, ozone, chemically active species, ultraviolet rays, and shock waves, which readily sterilize microorganisms and decompose molecules and materials. An application of this phenomenon to the cleaning of lakes and marshes is also described.

Chemical screening method for the rapid identification of microbial sources of marine invertebrate-associated metabolites.

PubMed

Berrue, Fabrice; Withers, Sydnor T; Haltli, Brad; Withers, Jo; Kerr, Russell G

2011-03-21

Marine invertebrates have proven to be a rich source of secondary metabolites. The growing recognition that marine microorganisms associated with invertebrate hosts are involved in the biosynthesis of secondary metabolites offers new alternatives for the discovery and development of marine natural products. However, the discovery of microorganisms producing secondary metabolites previously attributed to an invertebrate host poses a significant challenge. This study describes an efficient chemical screening method utilizing a 96-well plate-based bacterial cultivation strategy to identify and isolate microbial producers of marine invertebrate-associated metabolites.

Microbial engineering for the production of advanced biofuels.

PubMed

Peralta-Yahya, Pamela P; Zhang, Fuzhong; del Cardayre, Stephen B; Keasling, Jay D

2012-08-16

Advanced biofuels produced by microorganisms have similar properties to petroleum-based fuels, and can 'drop in' to the existing transportation infrastructure. However, producing these biofuels in yields high enough to be useful requires the engineering of the microorganism's metabolism. Such engineering is not based on just one specific feedstock or host organism. Data-driven and synthetic-biology approaches can be used to optimize both the host and pathways to maximize fuel production. Despite some success, challenges still need to be met to move advanced biofuels towards commercialization, and to compete with more conventional fuels.

High ethanol producing derivatives of Thermoanaerobacter ethanolicus

DOEpatents

Ljungdahl, L.G.; Carriera, L.H.

1983-05-24

Derivatives of the newly discovered microorganism Thermoanaerobacter ethanolicus which under anaerobic and thermophilic conditions continuously ferment substrates such as starch, cellobiose, glucose, xylose and other sugars to produce recoverable amounts of ethanol solving the problem of fermentations yielding low concentrations of ethanol using the parent strain of the microorganism Thermoanaerobacter ethanolicus are disclosed. These new derivatives are ethanol tolerant up to 10% (v/v) ethanol during fermentation. The process includes the use of an aqueous fermentation medium, containing the substrate at a substrate concentration greater than 1% (w/v).

High ethanol producing derivatives of Thermoanaerobacter ethanolicus

DOEpatents

Ljungdahl, Lars G.; Carriera, Laura H.

1983-01-01

Derivatives of the newly discovered microorganism Thermoanaerobacter ethanolicus which under anaerobic and thermophilic conditions continuously ferment substrates such as starch, cellobiose, glucose, xylose and other sugars to produce recoverable amounts of ethanol solving the problem of fermentations yielding low concentrations of ethanol using the parent strain of the microorganism Thermoanaerobacter ethanolicus are disclosed. These new derivatives are ethanol tolerant up to 10% (v/v) ethanol during fermentation. The process includes the use of an aqueous fermentation medium, containing the substrate at a substrate concentration greater than 1% (w/v).

Utilization of inulin-containing waste in industrial fermentations to produce biofuels and bio-based chemicals.

PubMed

Hughes, Stephen R; Qureshi, Nasib; López-Núñez, Juan Carlos; Jones, Marjorie A; Jarodsky, Joshua M; Galindo-Leva, Luz Ángela; Lindquist, Mitchell R

2017-04-01

Inulins are polysaccharides that belong to an important class of carbohydrates known as fructans and are used by many plants as a means of storing energy. Inulins contain 20 to several thousand fructose units joined by β-2,1 glycosidic bonds, typically with a terminal glucose unit. Plants with high concentrations of inulin include: agave, asparagus, coffee, chicory, dahlia, dandelion, garlic, globe artichoke, Jerusalem artichoke, jicama, onion, wild yam, and yacón. To utilize inulin as its carbon and energy source directly, a microorganism requires an extracellular inulinase to hydrolyze the glycosidic bonds to release fermentable monosaccharides. Inulinase is produced by many microorganisms, including species of Aspergillus, Kluyveromyces, Penicillium, and Pseudomonas. We review various inulinase-producing microorganisms and inulin feedstocks with potential for industrial application as well as biotechnological efforts underway to develop sustainable practices for the disposal of residues from processing inulin-containing crops. A multi-stage biorefinery concept is proposed to convert cellulosic and inulin-containing waste produced at crop processing operations to valuable biofuels and bioproducts using Kluyveromyces marxianus, Yarrowia lipolytica, Rhodotorula glutinis, and Saccharomyces cerevisiae as well as thermochemical treatments.

Histamine-producing Lactobacillus parabuchneri strains isolated from grated cheese can form biofilms on stainless steel.

PubMed

Diaz, Maria; Del Rio, Beatriz; Sanchez-Llana, Esther; Ladero, Victor; Redruello, Begoña; Fernández, María; Martin, M Cruz; Alvarez, Miguel A

2016-10-01

The consumption of food containing large amounts of histamine can lead to histamine poisoning. Cheese is one of the most frequently involved foods. Histamine, one of the biogenic amines (BAs) exhibiting the highest safety risk, accumulates in food contaminated by microorganisms with histidine decarboxylase activity. The origin of these microorganisms may be very diverse with contamination likely occurring during post-ripening processing, but the microorganisms involved during this manufacturing step have never been identified. The present work reports the isolation of 21 histamine-producing Lactobacillus parabuchneri strains from a histamine-containing grated cheese. PCR revealed that every isolate carried the histidine decarboxylase gene (hdcA). Eight lineages were identified based on the results of genome PFGE restriction analysis plus endonuclease restriction profile analysis of the carried plasmids. Members of all lineages were able to form biofilms on polystyrene and stainless steel surfaces. L. parabuchneri is therefore an undesirable species in the dairy industry; the biofilms it can produce on food processing equipment represent a reservoir of histamine-producing bacteria and thus a source of contamination of post-ripening-processed cheeses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Indole-3-acetic acid: A widespread physiological code in interactions of fungi with other organisms

PubMed Central

Fu, Shih-Feng; Wei, Jyuan-Yu; Chen, Hung-Wei; Liu, Yen-Yu; Lu, Hsueh-Yu; Chou, Jui-Yu

2015-01-01

Plants as well as microorganisms, including bacteria and fungi, produce indole-3-acetic acid (IAA). IAA is the most common plant hormone of the auxin class and it regulates various aspects of plant growth and development. Thus, research is underway globally to exploit the potential for developing IAA-producing fungi for promoting plant growth and protection for sustainable agriculture. Phylogenetic evidence suggests that IAA biosynthesis evolved independently in bacteria, microalgae, fungi, and plants. Present studies show that IAA regulates the physiological response and gene expression in these microorganisms. The convergent evolution of IAA production leads to the hypothesis that natural selection might have favored IAA as a widespread physiological code in these microorganisms and their interactions. We summarize recent studies of IAA biosynthetic pathways and discuss the role of IAA in fungal ecology. PMID:26179718

Yield and nutrient content of Bell Pepper pods from plants developed from seedlings inoculated, or not, with microorganisms

USDA-ARS?s Scientific Manuscript database

The effectiveness of microorganisms applied in production of vegetable transplants has had mixed results. Bell pepper (Capsicum annuum L.) transplants were produced in a greenhouse using organic methods and the organic certified potting mix was either not inoculated or inoculated with beneficial ba...

40 CFR 180.1011 - Viable spores of the microorganism Bacillus thuringiensis Berliner; exemption from the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1011 Viable spores of the... characteristics of the parent strain or contamination by other microorganisms. (3) Each lot of spore preparation... production is a Bacillus thuringiensis strain which does not produce β-exotoxin under standard manufacturing...

Culture-Dependent and -Independent Methods to Investigate the Predominant Microorganisms Associated with Wet Processed Coffee.

PubMed

Feng, Xiaomin; Dong, Honghong; Yang, Pan; Yang, Ruijuan; Lu, Jun; Lv, Jie; Sheng, Jun

2016-08-01

The fermentation process of Yunnan arabica coffee is a typical wet fermentation. Its excellent quality is closely related to microbes in the process of fermentation. The purpose of this study was to isolate and identify the microorganisms in the wet method of coffee processing in Yunnan Province, China. Microbial community structure and dominant bacterial species were evaluated by traditional cultivated separation method and PCR-DGGE technology, and were further analyzed in combination with the changes of organic acid content, activity of pectinase, and physical parameters (pH and temperature). A large number of microorganisms which can produce pectinase were found. Among them, Enterobacter cowanii, Pantoea agglomerans, Enterobacteriaceae bacterium, and Rahnella aquatilis were the predominant gram-negative bacteria, Bacillus cereus was the predominant gram-positive bacterium, Pichia kluyveri, Hanseniaspora uvarum, and Pichia fermentans were the predominant yeasts, and all those are pectinase-producing microorganisms. As for the contents of organic acids, oxalic was the highest, followed by acetic and lactic acids. Butyrate and propionate, which were unfavorable during the fermentation period, were barely discovered.

Native and heterologous production of bacteriocins from gram-positive microorganisms.

PubMed

Muñoz, Mabel; Jaramillo, Diana; Melendez, Adelina Del Pilar; J Alméciga-Diaz, Carlos; Sánchez, Oscar F

2011-12-01

In nature, microorganisms can present several mechanisms for setting intercommunication and defense. One of these mechanisms is related to the production of bacteriocins, which are peptides with antimicrobial activity. Bacteriocins can be found in Gram-positive and Gram-negative bacteria. Nevertheless, bacteriocins produced by Gram-positive bacteria are of particular interest due to the industrial use of several strains that belong to this group, especially lactic acid bacteria (LAB), which have the status of generally recognized as safe (GRAS) microorganisms. In this work, we will review recent tendencies in the field of invention and state of art related to bacteriocin production by Gram-positive microorganism. Hundred-eight patents related to Gram-positive bacteriocin producers have been disclosed since 1965, from which 57% are related bacteriocins derived from Lactococcus, Lactobacillus, Streptococcus, and Pediococcus strains. Surprisingly, patents regarding heterologous bacteriocins production were mainly presented just in the last decade. Although the major application of bacteriocins is concerned to food industry to control spoilage and foodborne bacteria, during the last years bacteriocin applications have been displacing to the diagnosis and treatment of cancer, and plant disease resistance and growth promotion.

Possibilities for extremophilic microorganisms in microbial electrochemical systems

PubMed Central

Dopson, Mark; Ni, Gaofeng; Sleutels, Tom HJA

2015-01-01

Microbial electrochemical systems exploit the metabolism of microorganisms to generate electrical energy or a useful product. In the past couple of decades, the application of microbial electrochemical systems has increased from the use of wastewaters to produce electricity to a versatile technology that can use numerous sources for the extraction of electrons on the one hand, while on the other hand these electrons can be used to serve an ever increasing number of functions. Extremophilic microorganisms grow in environments that are hostile to most forms of life and their utilization in microbial electrochemical systems has opened new possibilities to oxidize substrates in the anode and produce novel products in the cathode. For example, extremophiles can be used to oxidize sulfur compounds in acidic pH to remediate wastewaters, generate electrical energy from marine sediment microbial fuel cells at low temperatures, desalinate wastewaters and act as biosensors of low amounts of organic carbon. In this review, we will discuss the recent advances that have been made in using microbial catalysts under extreme conditions and show possible new routes that extremophilic microorganisms open for microbial electrochemical systems. PMID:26474966

Defensive properties of pyrrolizidine alkaloids against microorganisms.

PubMed

Joosten, Lotte; van Veen, Johannes A

2011-03-01

The understanding of the selection factors that drive chemical diversification of secondary metabolites of constitutive defence systems in plants, such as pyrrolizidine alkaloids (PAs), is still incomplete. Historically, plants always have been confronted with microorganisms. Long before herbivores existed on this planet, plants had to cope with microbial pathogens. Therefore, plant pathogenic microorganisms may have played an important role in the early evolution of the secondary metabolite diversity. In this review, we discuss the impact that plant-produced PAs have on plant-associated microorganisms. The objective of the review is to present the current knowledge on PAs with respect to anti-microbial activities, adaptation and detoxification by microorganisms, pathogenic fungi, root protection and PA induction. Many in vitro experiments showed effects of PAs on microorganisms. These results point to the potential of microorganisms to be important for the evolution of PAs. However, only a few in vivo studies have been published and support the results of the in vitro studies. In conclusion, the topics pointed out in this review need further exploration by carrying out ecological experiments and field studies.

Oil Production by a Consortium of Oleaginous Microorganisms grown on primary effluent wastewater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, Jacqueline; Hetrick, Mary; French, Todd

Municipal wastewater could be a potential growth medium that has not been considered for cultivating oleaginous microorganisms. This study is designed to determine if a consortium of oleaginous microorganism can successfully compete for carbon and other nutrients with the indigenous microorganisms contained in primary effluent wastewater. RESULTS: The oleaginous consortium inoculated with indigenous microorganisms reached stationary phase within 24 h, reaching a maximum cell concentration of 0.58 g L -1. Water quality post-oleaginous consortium growth reached a maximum chemical oxygen demand (COD) reduction of approximately 81%, supporting the consumption of the glucose within 8 h. The oleaginous consortium increased themore » amount of oil produced per gram by 13% compared with indigenous microorganisms in raw wastewater. Quantitative polymerase chain reaction (qPCR) results show a substantial population increase in bacteria within the first 24 h when the consortium is inoculated into raw wastewater. This result, along with the fatty acid methyl esters (FAMEs) results, suggests that conditions tested were not sufficient for the oleaginous consortium to compete with the indigenous microorganisms.« less

Yeast-like microorganisms in the scale insect Kermes quercus (Insecta, Hemiptera, Coccomorpha: Kermesidae). Newly acquired symbionts?

PubMed

Podsiadło, Elżbieta; Michalik, Katarzyna; Michalik, Anna; Szklarzewicz, Teresa

2018-01-01

Scale insects, like other plant sap-consumers, are host to symbiotic microorganisms which provide them with the substances missing from their diet. In contrast to most scale insects, Kermes quercus (Linnaeus) was regarded as asymbiotic. Our histological and ultrastructural observations show that in the body of the feeding stages of K. quercus collected in two locations (Warsaw and Cracow), numerous yeast-like microorganisms occur. These microorganisms were localized in the cytoplasm of fat body cells. The yeast-like microorganisms were observed neither in other organs of the host insect nor in the eggs. These microorganisms did not cause any damage to the structure of the ovaries and the course of oogenesis of the host insect. The females infected by them produced about 1300 larvae. The lack of these microorganisms in the cytoplasm of eggs indicates that they are not transmitted transovarially from mother to offspring. Molecular analyses indicated that the microorganisms which reside in the body of K. quercus are closely related to the entomopathogenic fungi Cordyceps and Ophiocordyceps, which belong to the Sordariomycetes class within the Ascomycota. The role of yeast-like microorganisms to their host insects remains unknown; however, it has been suggested that they may represent newly acquired symbionts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of novel drugs from marine surface associated microorganisms.

PubMed

Penesyan, Anahit; Kjelleberg, Staffan; Egan, Suhelen

2010-03-01

While the oceans cover more than 70% of the Earth's surface, marine derived microbial natural products have been largely unexplored. The marine environment is a habitat for many unique microorganisms, which produce biologically active compounds ("bioactives") to adapt to particular environmental conditions. For example, marine surface associated microorganisms have proven to be a rich source for novel bioactives because of the necessity to evolve allelochemicals capable of protecting the producer from the fierce competition that exists between microorganisms on the surfaces of marine eukaryotes. Chemically driven interactions are also important for the establishment of cross-relationships between microbes and their eukaryotic hosts, in which organisms producing antimicrobial compounds ("antimicrobials"), may protect the host surface against over colonisation in return for a nutrient rich environment. As is the case for bioactive discovery in general, progress in the detection and characterization of marine microbial bioactives has been limited by a number of obstacles, such as unsuitable culture conditions, laborious purification processes, and a lack of de-replication. However many of these limitations are now being overcome due to improved microbial cultivation techniques, microbial (meta-) genomic analysis and novel sensitive analytical tools for structural elucidation. Here we discuss how these technical advances, together with a better understanding of microbial and chemical ecology, will inevitably translate into an increase in the discovery and development of novel drugs from marine microbial sources in the future.

Plant signalling in symbiosis and immunity.

PubMed

Zipfel, Cyril; Oldroyd, Giles E D

2017-03-15

Plants encounter a myriad of microorganisms, particularly at the root-soil interface, that can invade with detrimental or beneficial outcomes. Prevalent beneficial associations between plants and microorganisms include those that promote plant growth by facilitating the acquisition of limiting nutrients such as nitrogen and phosphorus. But while promoting such symbiotic relationships, plants must restrict the formation of pathogenic associations. Achieving this balance requires the perception of potential invading microorganisms through the signals that they produce, followed by the activation of either symbiotic responses that promote microbial colonization or immune responses that limit it.

Stethoscopes as potential intrahospital carriers of pathogenic microorganisms.

PubMed

Campos-Murguía, Alejandro; León-Lara, Ximena; Muñoz, Juan M; Macías, Alejandro E; Alvarez, José A

2014-01-01

Stethoscopes can take part in the transmission of health care-associated infections. We cultured 112 stethoscopes by direct imprint on blood agar to estimate the prevalence of potentially pathogenic microorganisms. Forty-eight (47%) produced 50 potentially pathogenic microorganisms; from these, 43 (86%) were Staphylococcus aureus, of which 18 (42%) were methicillin-resistant S. aureus. We concluded that stethoscopes should be considered as potential fomites and must be disinfected routinely before and after each patient contact. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Fermentation process using specific oxygen uptake rates as a process control

DOEpatents

Van Hoek, Pim; Aristidou, Aristos; Rush, Brian J.

2016-08-30

Specific oxygen uptake (OUR) is used as a process control parameter in fermentation processes. OUR is determined during at least the production phase of a fermentation process, and process parameters are adjusted to maintain the OUR within desired ranges. The invention is particularly applicable when the fermentation is conducted using a microorganism having a natural PDC pathway that has been disrupted so that it no longer functions. Microorganisms of this sort often produce poorly under strictly anaerobic conditions. Microaeration controlled by monitoring OUR allows the performance of the microorganism to be optimized.

Fermentation process using specific oxygen uptake rates as a process control

DOEpatents

Van Hoek, Pim [Minnetonka, MN; Aristidou, Aristos [Maple Grove, MN; Rush, Brian [Minneapolis, MN

2011-05-10

Specific oxygen uptake (OUR) is used as a process control parameter in fermentation processes. OUR is determined during at least the production phase of a fermentation process, and process parameters are adjusted to maintain the OUR within desired ranges. The invention is particularly applicable when the fermentation is conducted using a microorganism having a natural PDC pathway that has been disrupted so that it no longer functions. Microorganisms of this sort often produce poorly under strictly anaerobic conditions. Microaeration controlled by monitoring OUR allows the performance of the microorganism to be optimized.

Fermentation process using specific oxygen uptake rates as a process control

DOEpatents

Hoek, Van; Pim, Aristidou [Minnetonka, MN; Aristos, Rush [Maple Grove, MN; Brian, [Minneapolis, MN

2007-06-19

Specific oxygen uptake (OUR) is used as a process control parameter in fermentation processes. OUR is determined during at least the production phase of a fermentation process, and process parameters are adjusted to maintain the OUR within desired ranges. The invention is particularly applicable when the fermentation is conducted using a microorganism having a natural PDC pathway that has been disrupted so that it no longer functions. Microorganisms of this sort often produce poorly under strictly anaerobic conditions. Microaeration controlled by monitoring OUR allows the performance of the microorganism to be optimized.

Fermentation process using specific oxygen uptake rates as a process control

DOEpatents

Van Hoek, Pim; Aristidou, Aristos; Rush, Brian

2014-09-09

Specific oxygen uptake (OUR) is used as a process control parameter in fermentation processes. OUR is determined during at least the production phase of a fermentation process, and process parameters are adjusted to maintain the OUR within desired ranges. The invention is particularly applicable when the fermentation is conducted using a microorganism having a natural PDC pathway that has been disrupted so that it no longer functions. Microorganisms of this sort often produce poorly under strictly anaerobic conditions. Microaeration controlled by monitoring OUR allows the performance of the microorganism to be optimized.

Advances in postharvest technologies to extend the storage life of minimally processed fruits and vegetables.

PubMed

Ali, Asgar; Yeoh, Wei Keat; Forney, Charles; Siddiqui, Mohammed Wasim

2017-10-26

Minimally processed fresh produce is one of the fastest growing segments of the food industry due to consumer demand for fresh, healthy, and convenient foods. However, mechanical operations of cutting and peeling induce the liberation of cellular contents at the site of wounding that can promote the growth of pathogenic and spoilage microorganisms. In addition, rates of tissue senescence can be enhanced resulting in reduced storage life of fresh-cut fruits and vegetables. Chlorine has been widely adopted in the disinfection and washing procedures of fresh-cut produce due to its low cost and efficacy against a broad spectrum of microorganisms. Continuous replenishment of chlorine in high organic wash water can promote the formation of carcinogenic compounds such as trihalomethanes, which threaten human and environmental health. Alternative green and innovative chemical and physical postharvest treatments such as ozone, electrolyzed water, hydrogen peroxide, ultraviolet radiation, high pressure processing, and ultrasound can achieve similar reduction of microorganisms as chlorine without the production of harmful compounds or compromising the quality of fresh-cut produce.

Methods for microbial filtration of fluids

DOEpatents

Carman, Margaret L.; Jackson, Kenneth J.; Knapp, Richard B.; Knezovich, John P.; Shah, Nilesh N.; Taylor, Robert T.

1996-01-01

Novel methods for purifying contaminated subsurface groundwater are disclosed. The method is involves contacting the contaminated subsurface groundwater with methanotrophic or heterotrophic microorganisms which produce contaminant-degrading enzymes. The microorganisms are derived from surface cultures and are injected into the ground so as to act as a biofilter. The contaminants which may be treated include organic or metallic materials and radionuclides.

Cloning of a heavy-metal-binding protein derived from activated-sludge microorganisms.

PubMed

Sano, Daisuke; Myojo, Ken; Omura, Tatsuo

2006-09-01

A gene of the heavy-metal-binding protein (HMBP) was newly isolated from a genetic DNA library of activated-sludge microorganisms. HMBP was produced by transformed Escherichia coli, and the copper-binding ability of HMBP was confirmed. HMBP derived from activated sludge could be available as heavy metal adsorbents in water and wastewater treatments.

Furfural and 5-hydroxymethyl-furfural degradation using recombinant manganese peroxidase.

PubMed

Yee, Kelsey L; Jansen, Lauren E; Lajoie, Curtis A; Penner, Michael H; Morse, Lettie; Kelly, Christine J

2018-01-01

Biomass pretreatment-derived degradation compounds, such as furfural and 5-hydroxymethyl-furfural (HMF), inhibit the growth of fermentation microorganisms that utilize biomass to produce fuels and chemicals. Here we report that recombinant manganese peroxidase (rMnP) produced from the yeast Pichia pastoris can degrade furfural and HMF making them less toxic to microorganisms. Treatment with rMnP or manganese(III) acetate reduced furfural and HMF concentrations in a dose-dependent manner. Furfural disappearance was accompanied by malonate disappearance and accumulation of four distinct degradation products. Furfural was more readily degraded by rMnP and manganese(III) acetate than HMF. Growth assays using Saccharomyces cerevisiae indicated that rMnP treatment reduced the toxicity of furfural and HMF. This work provides an avenue to use rMnP to increase the growth of fermentation microorganisms that are inhibited by toxic compounds derived from pretreatment of biomass. Copyright © 2017 Elsevier Inc. All rights reserved.

Melanins and Resistance of Fungi to Lysis

PubMed Central

Bloomfield, B. J.; Alexander, M.

1967-01-01

Hyphal walls of Aspergillus phoenicis and Sclerotium rolfsii are composed of large amounts of glucose- and N-acetylhexosamine-containing polysaccharides, and the walls are extensively digested by streptomycete culture filtrates or by a mixture of purified chitinase and β-(1 → 3) glucanase preparations with the release of the monomeric units. A. phoenicis conidial walls also contain polymers of glucose and N-acetylhexosamine, but these walls are resistant to digestion by microorganisms or the enzyme combination active on the hyphae. When the melanin-containing spicules were removed from the spore surface, however, the chitinase and glucanase partially digested the underlying structural components. Microorganisms decomposing hyphal walls of S. rolfsii did not attack the melanin-covered sclerotia produced by this fungus. No microorganism capable of lysing two fungi, Rhizoctonia solani and Cladosporium sp., producing hyphae containing abundant melanin was found. The ecological significance of these findings and possible mechanisms for the protective influence associated with melanins are discussed. PMID:6032507

Natural Oil Production from Microorganisms: Bioprocess and Microbe Engineering for Total Carbon Utilization in Biofuel Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-07-15

Electrofuels Project: MIT is using carbon dioxide (CO2) and hydrogen generated from electricity to produce natural oils that can be upgraded to hydrocarbon fuels. MIT has designed a 2-stage biofuel production system. In the first stage, hydrogen and CO2 are fed to a microorganism capable of converting these feedstocks to a 2-carbon compound called acetate. In the second stage, acetate is delivered to a different microorganism that can use the acetate to grow and produce oil. The oil can be removed from the reactor tank and chemically converted to various hydrocarbons. The electricity for the process could be supplied frommore » novel means currently in development, or more proven methods such as the combustion of municipal waste, which would also generate the required CO2 and enhance the overall efficiency of MIT’s biofuel-production system.« less

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.

Environmental Applications of Biosurfactants: Recent Advances

PubMed Central

Pacwa-Płociniczak, Magdalena; Płaza, Grażyna A.; Piotrowska-Seget, Zofia; Cameotra, Swaranjit Singh

2011-01-01

Increasing public awareness of environmental pollution influences the search and development of technologies that help in clean up of organic and inorganic contaminants such as hydrocarbons and metals. An alternative and eco-friendly method of remediation technology of environments contaminated with these pollutants is the use of biosurfactants and biosurfactant-producing microorganisms. The diversity of biosurfactants makes them an attractive group of compounds for potential use in a wide variety of industrial and biotechnological applications. The purpose of this review is to provide a comprehensive overview of advances in the applications of biosurfactants and biosurfactant-producing microorganisms in hydrocarbon and metal remediation technologies. PMID:21340005

Extractive Fermentation of Sugarcane Juice to Produce High Yield and Productivity of Bioethanol

NASA Astrophysics Data System (ADS)

Rofiqah, U.; Widjaja, T.; Altway, A.; Bramantyo, A.

2017-04-01

Ethanol production by batch fermentation requires a simple process and it is widely used. Batch fermentation produces ethanol with low yield and productivity due to the accumulation of ethanol in which poisons microorganisms in the fermenter. Extractive fermentation technique is applied to solve the microorganism inhibition problem by ethanol. Extractive fermentation technique can produce ethanol with high yield and productivity. In this process raffinate still, contains much sugar because conversion in the fermentation process is not perfect. Thus, to enhance ethanol yield and productivity, recycle system is applied by returning the raffinate from the extraction process to the fermentation process. This raffinate also contains ethanol which would inhibit the performance of microorganisms in producing ethanol during the fermentation process. Therefore, this study aims to find the optimum condition for the amount of solvent to broth ratio (S: B) and recycle to fresh feed ratio (R: F) which enter the fermenter to produce high yield and productivity. This research was carried out by experiment. In the experiment, sugarcane juice was fermented using Zymomonasmobilis mutant. The fermentation broth was extracted using amyl alcohol. The process was integrated with the recycle system by varying the recycle ratio. The highest yield and productivity is 22.3901% and 103.115 g / L.h respectively, obtained in a process that uses recycle to fresh feed ratio (R: F) of 50:50 and solvents to both ratio of 1.

Microbial diversity in Paris polyphylla var. yunnanensis rhizomes of varying ages.

PubMed

Yang, Y; Yang, S C; Zhao, J; Udikeri, S; Liu, T

2015-12-21

Endophyte microorganisms live inside plants without causing them any apparent damage. Recently, endophytic microorganisms have attracted attention because they can produce bioactive compounds of biotechnological interest. The endophytic microorganisms in Paris polyphylla var. yunnanensis (Liliaceae) - a species used since antiquity in traditional Chinese medicine - are under scrutiny because they may be responsible for producing the bioactive metabolites associated with the plant. The levels of bioactive metabolites in the rhizomes of P. polyphylla increase with rhizome age. To elucidate the roles played by endophytes in the accumulation of bioactive metabolites, we investigated the community structure and diversity of the endophytic microorganisms in P. polyphylla rhizomes of different ages (4, 6, and 8 years) using 16S rRNA and internal transcribed spacer (ITS) sequence analysis. 16S rDNA amplicon pyrosequencing revealed that the number of operational taxonomic units was lower in the 8-year-old samples than in the other samples. A total of 28 phyla were observed in the P. polyphylla samples and the predominant bacteria were of the Cyanobacteria and Proteobacteria phyla. Moreover, the percentage of Cyanobacteria increased with rhizome age. Similarly, ITS1 amplicon pyrosequencing identified developmental changes in the most abundant fungal classes; some classes were more prevalent in the 8-year-old rhizomes than in younger rhizomes, indicating the importance in secondary metabolism in older rhizomes. Our study showed that endophyte microorganism diversity and prevalence depend on P. polyphylla rhizome age. There was also an indication that some endophyte microorganisms contribute to the higher saponin content in older P. polyphylla specimens.

Production of functional probiotic, prebiotic, and synbiotic ice creams.

PubMed

Di Criscio, T; Fratianni, A; Mignogna, R; Cinquanta, L; Coppola, R; Sorrentino, E; Panfili, G

2010-10-01

In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria after frozen storage that met the minimum required to achieve probiotic effects. Moreover, most of the ice creams showed good nutritional and sensory properties, with the best results obtained with Lb. casei and 2.5% inulin. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Green synthesis of silver nanoparticles combined to calcium glycerophosphate: antimicrobial and antibiofilm activities.

PubMed

Souza, José As; Barbosa, Debora B; Berretta, Andresa A; do Amaral, Jackeline G; Gorup, Luiz F; de Souza Neto, Francisco N; Fernandes, Renan A; Fernandes, Gabriela L; Camargo, Emerson R; Agostinho, Alessandra M; Delbem, Alberto Cb

2018-03-01

To synthesize, characterize and evaluate the antimicrobial and antibiofilm activities of novel nanocomposites containing silver nanoparticles (AgNPs) associated or not to β-calcium glycerophosphate. These nanocomposites were produced through a 'green' route using extracts of different parts of pomegranate. Antimicrobial and antibiofilm properties against Candida albicans and Streptococcus mutans were determined by the minimum bactericidal/fungicidal concentration and biofilm density after treatments. All extracts used were successful in producing AgNPs. Composites made with peel extracts showed the highest antimicrobial and antibiofilm activity against both microorganisms tested and performed similarly or even better than chlorhexidine. AgNPs associated or not to calcium glycerophosphate produced by a 'green' process may be a promising novel antimicrobial agent against oral microorganisms.

Methods for microbial filtration of fluids

DOEpatents

Carman, M.L.; Jackson, K.J.; Knapp, R.B.; Knezovich, J.P.; Shah, N.N.; Taylor, R.T.

1996-01-30

Novel methods for purifying contaminated subsurface groundwater are disclosed. The method is involves contacting the contaminated subsurface groundwater with methanotrophic or heterotrophic microorganisms which produce contaminant-degrading enzymes. The microorganisms are derived from surface cultures and are injected into the ground so as to act as a biofilter. The contaminants which may be treated include organic or metallic materials and radionuclides. 8 figs.

Method of sterilization using ozone

NASA Technical Reports Server (NTRS)

Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

2002-01-01

Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize, organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganism and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.

How to sustainably feed a microbe: Strategies for biological production of carbon-based commodities with renewable electricity

DOE PAGES

Butler, Caitlyn S.; Lovley, Derek R.

2016-11-28

As interest and application of renewable energy grows, strategies are needed to align the asynchronous supply and demand. Microbial metabolisms are a potentially sustainable mechanism for transforming renewable electrical energy into biocommodities that are easily stored and transported. Acetogens and methanogens can reduce carbon dioxide to organic products including methane, acetic acid, and ethanol. The library of biocommodities is expanded when engineered metabolisms of acetogens are included. Typically, electrochemical systems are employed to integrate renewable energy sources with biological systems for production of carbon-based commodities. Within these systems, there are three prevailing mechanisms for delivering electrons to microorganisms for themore » conversion of carbon dioxide to reduce organic compounds: (1) electrons can be delivered to microorganisms via H 2 produced separately in a electrolyzer, (2) H 2 produced at a cathode can convey electrons to microorganisms supported on the cathode surface, and (3) a cathode can directly feed electrons to microorganisms. Each of these strategies has advantages and disadvantages that must be considered in designing full-scale processes. Furthermore, this review considers the evolving understanding of each of these approaches and the state of design for advancing these strategies toward viability.« less

Impact on Human Health of Microorganisms Present in Fermented Dairy Products: An Overview

PubMed Central

Fernández, María; Hudson, John Andrew; de los Reyes-Gavilán, Clara G.

2015-01-01

Fermented dairy products provide nutrients in our diet, some of which are produced by the action of microorganisms during fermentation. These products can be populated by a diverse microbiota that impacts the organoleptic and physicochemical characteristics foods as well as human health. Acidification is carried out by starter lactic acid bacteria (LAB) whereas other LAB, moulds, and yeasts become dominant during ripening and contribute to the development of aroma and texture in dairy products. Probiotics are generally part of the nonstarter microbiota, and their use has been extended in recent years. Fermented dairy products can contain beneficial compounds, which are produced by the metabolic activity of their microbiota (vitamins, conjugated linoleic acid, bioactive peptides, and gamma-aminobutyric acid, among others). Some microorganisms can also release toxic compounds, the most notorious being biogenic amines and aflatoxins. Though generally considered safe, fermented dairy products can be contaminated by pathogens. If proliferation occurs during manufacture or storage, they can cause sporadic cases or outbreaks of disease. This paper provides an overview on the current state of different aspects of the research on microorganisms present in dairy products in the light of their positive or negative impact on human health. PMID:25839033

Impact on human health of microorganisms present in fermented dairy products: an overview.

PubMed

Fernández, María; Hudson, John Andrew; Korpela, Riitta; de los Reyes-Gavilán, Clara G

2015-01-01

Fermented dairy products provide nutrients in our diet, some of which are produced by the action of microorganisms during fermentation. These products can be populated by a diverse microbiota that impacts the organoleptic and physicochemical characteristics foods as well as human health. Acidification is carried out by starter lactic acid bacteria (LAB) whereas other LAB, moulds, and yeasts become dominant during ripening and contribute to the development of aroma and texture in dairy products. Probiotics are generally part of the nonstarter microbiota, and their use has been extended in recent years. Fermented dairy products can contain beneficial compounds, which are produced by the metabolic activity of their microbiota (vitamins, conjugated linoleic acid, bioactive peptides, and gamma-aminobutyric acid, among others). Some microorganisms can also release toxic compounds, the most notorious being biogenic amines and aflatoxins. Though generally considered safe, fermented dairy products can be contaminated by pathogens. If proliferation occurs during manufacture or storage, they can cause sporadic cases or outbreaks of disease. This paper provides an overview on the current state of different aspects of the research on microorganisms present in dairy products in the light of their positive or negative impact on human health.

How to sustainably feed a microbe: Strategies for biological production of carbon-based commodities with renewable electricity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butler, Caitlyn S.; Lovley, Derek R.

As interest and application of renewable energy grows, strategies are needed to align the asynchronous supply and demand. Microbial metabolisms are a potentially sustainable mechanism for transforming renewable electrical energy into biocommodities that are easily stored and transported. Acetogens and methanogens can reduce carbon dioxide to organic products including methane, acetic acid, and ethanol. The library of biocommodities is expanded when engineered metabolisms of acetogens are included. Typically, electrochemical systems are employed to integrate renewable energy sources with biological systems for production of carbon-based commodities. Within these systems, there are three prevailing mechanisms for delivering electrons to microorganisms for themore » conversion of carbon dioxide to reduce organic compounds: (1) electrons can be delivered to microorganisms via H 2 produced separately in a electrolyzer, (2) H 2 produced at a cathode can convey electrons to microorganisms supported on the cathode surface, and (3) a cathode can directly feed electrons to microorganisms. Each of these strategies has advantages and disadvantages that must be considered in designing full-scale processes. Furthermore, this review considers the evolving understanding of each of these approaches and the state of design for advancing these strategies toward viability.« less

How to Sustainably Feed a Microbe: Strategies for Biological Production of Carbon-Based Commodities with Renewable Electricity.

PubMed

Butler, Caitlyn S; Lovley, Derek R

2016-01-01

As interest and application of renewable energy grows, strategies are needed to align the asynchronous supply and demand. Microbial metabolisms are a potentially sustainable mechanism for transforming renewable electrical energy into biocommodities that are easily stored and transported. Acetogens and methanogens can reduce carbon dioxide to organic products including methane, acetic acid, and ethanol. The library of biocommodities is expanded when engineered metabolisms of acetogens are included. Typically, electrochemical systems are employed to integrate renewable energy sources with biological systems for production of carbon-based commodities. Within these systems, there are three prevailing mechanisms for delivering electrons to microorganisms for the conversion of carbon dioxide to reduce organic compounds: (1) electrons can be delivered to microorganisms via H 2 produced separately in a electrolyzer, (2) H 2 produced at a cathode can convey electrons to microorganisms supported on the cathode surface, and (3) a cathode can directly feed electrons to microorganisms. Each of these strategies has advantages and disadvantages that must be considered in designing full-scale processes. This review considers the evolving understanding of each of these approaches and the state of design for advancing these strategies toward viability.

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.

A Simple and Low-Cost Procedure for Growing Geobacter sulfurreducens Cell Cultures and Biofilms in Bioelectrochemical Systems

PubMed Central

O’Brien, J. Patrick; Malvankar, Nikhil S.

2017-01-01

Anaerobic microorganisms play a central role in several environmental processes and regulate global biogeochemical cycling of nutrients and minerals. Many anaerobic microorganisms are important for the production of bioenergy and biofuels. However, the major hurdle in studying anaerobic microorganisms in the laboratory is the requirement for sophisticated and expensive gassing stations and glove boxes to create and maintain the anaerobic environment. This appendix presents a simple design for a gassing station that can be used readily by an inexperienced investigator for cultivation of anaerobic microorganisms. In addition, this appendix also details the low-cost assembly of bioelectrochemical systems and outlines a simplified procedure for cultivating and analyzing bacterial cell cultures and biofilms that produce electric current, using Geobacter sulfurreducens as a model organism. PMID:27858972

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. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Soil microorganisms alleviate the allelochemical effects of a thyme monoterpene on the performance of an associated grass species.

PubMed

Ehlers, Bodil K

2011-01-01

Plant allelochemicals released into the soil can significantly impact the performance of associated plant species thereby affecting their competitive ability. Soil microbes can potentially affect the interaction between plant and plant chemicals by degrading the allelochemicals. However, most often plant-plant chemical interactions are studied using filter paper bioassays examining the pair-wise interaction between a plant and a plant chemical, not taking into account the potential role of soil microorganisms. To explore if the allelopathic effects on a grass by the common thyme monoterpene "carvacrol" are affected by soil microorganisms. Seedlings of the grass Agrostis capillaris originating from 3 different thyme sites were raised in the greenhouse. Seedlings were grown under four different soil treatments in a 2*2 fully factorial experiment. The monoterpene carvacrol was either added to standard greenhouse soil or left out, and soil was either sterilized (no soil microorganisms) or not (soil microorganisms present in soil). The presence of carvacrol in the soil strongly increased mortality of Agrostis plants, and this increase was highest on sterile soil. Plant biomass was reduced on soil amended with carvacrol, but only when the soil was also sterilized. Plants originating from sites where thyme produces essential oils containing mostly carvacrol had higher survival on soil treated with that monoterpene than plants originating from a site where thyme produced different types of terpenes, suggesting an adaptive response to the locally occurring terpene. The study shows that presence of soil microorganisms can alleviate the negative effect of a common thyme monoterpene on the performance of an associated plant species, emphasizing the role of soil microbes in modulating plant-plant chemical interactions.

Soil Microorganisms Alleviate the Allelochemical Effects of a Thyme Monoterpene on the Performance of an Associated Grass Species

PubMed Central

Ehlers, Bodil K.

2011-01-01

Background Plant allelochemicals released into the soil can significantly impact the performance of associated plant species thereby affecting their competitive ability. Soil microbes can potentially affect the interaction between plant and plant chemicals by degrading the allelochemicals. However, most often plant-plant chemical interactions are studied using filter paper bioassays examining the pair-wise interaction between a plant and a plant chemical, not taking into account the potential role of soil microorganisms. Methodology/Principal findings To explore if the allelopathic effects on a grass by the common thyme monoterpene “carvacrol” are affected by soil microorganisms. Seedlings of the grass Agrostis capillaris originating from 3 different thyme sites were raised in the greenhouse. Seedlings were grown under four different soil treatments in a 2*2 fully factorial experiment. The monoterpene carvacrol was either added to standard greenhouse soil or left out, and soil was either sterilized (no soil microorganisms) or not (soil microorganisms present in soil). The presence of carvacrol in the soil strongly increased mortality of Agrostis plants, and this increase was highest on sterile soil. Plant biomass was reduced on soil amended with carvacrol, but only when the soil was also sterilized. Plants originating from sites where thyme produces essential oils containing mostly carvacrol had higher survival on soil treated with that monoterpene than plants originating from a site where thyme produced different types of terpenes, suggesting an adaptive response to the locally occurring terpene. Conclusions/Significance The study shows that presence of soil microorganisms can alleviate the negative effect of a common thyme monoterpene on the performance of an associated plant species, emphasizing the role of soil microbes in modulating plant-plant chemical interactions. PMID:22125596

Surface Disinfectants for Burn Units Evaluated by a New Double Method, Using Microorganisms Recently Isolated From Patients, on a Surface Germ-Carrier Model.

PubMed

Herruzo, Rafael; Vizcaino, Maria Jose; Herruzo, Irene; Sanchez, Manuel

Assessment methods of surface disinfection based on international standards (Environmental Protection Agency, European Norms, etc) do not correspond to hospital reality. New evaluation methods of surfaces disinfection are proposed to choose the most suitable disinfectant to act against clinically relevant microorganisms detected on the surfaces of burn units. 1) "Immediate effect": 6 products were compared using a glass germ-carrier and 20 recently isolated microorganisms from different patients in the intensive care units. Disinfectants were applied with microfiber cloths. Log10 reductions were calculated for colony forming units produced after 15 minutes of disinfectant application. 2) "Residual effect": the glass germ-carriers were previously impregnated with one of the studied disinfectants. After a 30-minute wait period, they were then contaminated with 1 microorganism (from the 20 above-mentioned). After 15 minutes, the disinfectant was inhibited and the log10 reduction of colony forming units was assessed. The immediate effect (disinfection and microorganism dragging and transferring from the surface to the cloth) produced complete elimination of the inoculums for all products used except one (a diluted quaternary ammonium). The average residual effect found on the 20 microorganisms was moderate: 2 to 3 log10 colony forming unit reduction with chlorine dioxide or 0.5% chlorhexidine (and lower with the other products), obtaining surfaces refractory to recontamination, at least, during 30 minutes. Two tests should be performed before advising surface disinfectant: 1) direct effect and 2) residual efficacy. These characteristics should be considered when a new surface disinfectant is chosen. Chlorine dioxide has a similar or better direct effect than sodium hypochlorite and a similar residual effect than chlorhexidine.

Studies on the Mechanisms of Microbial Adaptation to the Physical Environment

NASA Technical Reports Server (NTRS)

Heinrich, M. R.; Tromp, S. W. (Editor); Bouma, J. J. (Editor)

1979-01-01

The environmental factors which affect humans and other animals also influence the microorganisms which are such an important part of our ecology. Some of the microorganisms are very closely associated with animals, living in the digestive tract and synthesizing essential nutrients for the host. For these microbes, most external physical changes are of little consequence, because they are well shielded by the animals' homeostatic systems. The vast majority of microorganisms, however, live free in nature, especially in the soil and oceans. It has been estimated that the upper 15 cm of a fertile soil may contain over 4000 kg of bacteria and fungi per hectare. These organisms are responsible for degrading the complex molecules of plants and animals when they die, eventually producing simple organics, carbon dioxide, and inorganics, which are then used for the next cycle of plant growth. It is believed that over 90 % of the biologically produced carbon dioxide results from the metabolic activity of bacteria and fungi. In addition to recycling plant nutrients, soil bacteria also provide new nutrients through 'fixation' of atmospheric nitrogen into ammonia and nitrate, the forms which can be used by plants. Microorganisms so have an enormous capacity for detoxifying both natural and man-made poisons. All of these functions of microorganisms are essential to the operation of the material cycles on Earth. This is true of all locations on the planet, regardless of the climate or other environmental factors. In fact, one of the most impressive attributes of microorganisms is their ability to adapt to every stable environment on Earth. These include such extremes as polar regions, hot springs, water saturated with salt, mountain tops, ocean depths, acid and alkaline waters, deserts, intense radioactivity, soil and water contaminated with toxic chemicals or petroleum, and areas devoid of oxygen.

Carbon Dioxide Corrosion and Acetate: A Hypothesis on the Influence of Microorganisms

DTIC Science & Technology

2008-11-01

thermocatalytic degradation of kero- gen,5 oxidation of suitable acid precursors," "and the pyrolytic destruction of kerogen or oil components.*IS... oil industry. Both chemical compounds can be produced and consumed by microorganisms during the anaerobic biodegradation of organic matter- including...hydrocarbons. We contend that the principles governing anaerobic biodegration activity can be extrapolated to above ground oil production facilities

Electrochemical production of ozone and hydrogen peroxide

NASA Technical Reports Server (NTRS)

Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

1999-01-01

Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganisms and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.

Low oxygen levels contribute to improve photohydrogen production in mixotrophic non-stressed Chlamydomonas cultures

DOE PAGES

Jurado-Oller, Jose Luis; Dubini, Alexandra; Galvan, Aurora; ...

2015-09-17

Currently, hydrogen fuel is derived mainly from fossil fuels, but there is an increasing interest in clean and sustainable technologies for hydrogen production. In this context, the ability of some photosynthetic microorganisms, particularly cyanobacteria and microalgae, to produce hydrogen is a promising alternative for renewable, clean-energy production. Among a diverse array of photosynthetic microorganisms able to produce hydrogen, the green algae Chlamydomonas reinhardtii is the model organism widely used to study hydrogen production. Furthermore, the well-known fact that acetate-containing medium enhances hydrogen production in this algae, little is known about the precise role of acetate during this process.

Importance of lactic acid bacteria in Asian fermented foods

PubMed Central

2011-01-01

Lactic acid bacteria play important roles in various fermented foods in Asia. Besides being the main component in kimchi and other fermented foods, they are used to preserve edible food materials through fermentation of other raw-materials such as rice wine/beer, rice cakes, and fish by producing organic acids to control putrefactive microorganisms and pathogens. These bacteria also provide a selective environment favoring fermentative microorganisms and produce desirable flavors in various fermented foods. This paper discusses the role of lactic acid bacteria in various non-dairy fermented food products in Asia and their nutritional and physiological functions in the Asian diet. PMID:21995342

Functional Characterization of Bacteria Isolated from Ancient Arctic Soil Exposes Diverse Resistance Mechanisms to Modern Antibiotics

PubMed Central

Perron, Gabriel G.; Whyte, Lyle; Turnbaugh, Peter J.; Goordial, Jacqueline; Hanage, William P.; Dantas, Gautam; Desai, Michael M.

2015-01-01

Using functional metagenomics to study the resistomes of bacterial communities isolated from different layers of the Canadian high Arctic permafrost, we show that microbial communities harbored diverse resistance mechanisms at least 5,000 years ago. Among bacteria sampled from the ancient layers of a permafrost core, we isolated eight genes conferring clinical levels of resistance against aminoglycoside, β-lactam and tetracycline antibiotics that are naturally produced by microorganisms. Among these resistance genes, four also conferred resistance against amikacin, a modern semi-synthetic antibiotic that does not naturally occur in microorganisms. In bacteria sampled from the overlaying active layer, we isolated ten different genes conferring resistance to all six antibiotics tested in this study, including aminoglycoside, β-lactam and tetracycline variants that are naturally produced by microorganisms as well as semi-synthetic variants produced in the laboratory. On average, we found that resistance genes found in permafrost bacteria conferred lower levels of resistance against clinically relevant antibiotics than resistance genes sampled from the active layer. Our results demonstrate that antibiotic resistance genes were functionally diverse prior to the anthropogenic use of antibiotics, contributing to the evolution of natural reservoirs of resistance genes. PMID:25807523

The effect of anaerobic fermentation processing of cattle waste for biogas as a renewable energy resources on the number of contaminant microorganism

NASA Astrophysics Data System (ADS)

Kurnani, Tb. Benito A.; Hidayati, Yuli Astuti; Marlina, Eulis Tanti; Harlia, Ellin

2016-02-01

Beef cattle waste has a positive potential that can be exploited, as well as a negative potential that must be controlled so as not to pollute the environment. Beef cattle waste can be processed into an alternative energy, namely biogas. Anaerobic treatment of livestock waste to produce gas can be a solution in providing optional energy, while the resulted sludge as the fermentation residue can be used as organic fertilizer for crops. However, this sludge may containt patogenic microorganism that will damage human and environmet healt. Therefor, this study was aimed to know the potency of beef cattle waste to produce biogas and the decrease of the microorganism's number by using fixed dome digester. Beef cattle waste was processed into biogas using fixed dome digester with a capacity of 12 m3. Biogas composition was measured using Gas Cromatografi, will microorganism species was identified using Total plate Count Methode. The result of this study shows that the produced biogas contains of 75.77% Mol (CH4), 13.28% Mol (N), and 6.96% Mol (CO2). Furthermor, this study show that the anaerobic fermrntation process is capable of reducing microorganisms that could potentially pollute the environment. The number of Escherichia coli and Samonella sp. were <30 MPN/ml respectively save for environment. This process can reduce 84.70% the amount of molds. The only molds still existed after fermentation was A.fumigatus. The number of protozoa can be reduced in order of 94.73%. Protozoa that can be identified in cattle waste before, and after anaerobic fermentation was merely Eimeria sp.. The process also reduced the yeast of 86.11%. The remaining yeast after fermentation was Candida sp. Finally, about 93.7% of endoparasites was reduced by this process. In this case, every trematode and cestoda were 100% reduced, while the nematode only 75%. Reducing some microorganisms that have the potential to pollute the environment signifies sludge anaerobic fermentation residue is safe to be applied as organic fertilizer for crops.

Microbiology of organic and conventionally grown fresh produce.

PubMed

Maffei, Daniele F; Batalha, Erika Y; Landgraf, Mariza; Schaffner, Donald W; Franco, Bernadette D G M

2016-12-01

Fresh produce is a generalized term for a group of farm-produced crops, including fruits and vegetables. Organic agriculture has been on the rise and attracting the attention of the food production sector, since it uses eco-agricultural principles that are ostensibly environmentally-friendly and provides products potentially free from the residues of agrochemicals. Organic farming practices such as the use of animal manure can however increase the risk of contamination by enteric pathogenic microorganisms and may consequently pose health risks. A number of scientific studies conducted in different countries have compared the microbiological quality of produce samples from organic and conventional production and results are contradictory. While some have reported greater microbial counts in fresh produce from organic production, other studies do not. This manuscript provides a brief review of the current knowledge and summarizes data on the occurrence of pathogenic microorganisms in vegetables from organic production. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Direct and Indirect Effects of Animal Detritus on Growth, Survival, and Mass of Invasive Container Mosquito Aedes albopictus (Diptera: Culicidae)

PubMed Central

YEE, DONALD A.; KESAVARAJU, BANUGOPAN; JULIANO, STEVEN A.

2007-01-01

Compared with plant detritus, animal detritus yields higher growth rates, survival, adult mass, and population growth of container-dwelling mosquitoes. It is unclear whether the benefit from animal detritus to larvae results from greater microorganism growth, direct ingestion of animal detritus by larvae, or some other mechanism. We tested alternative mechanisms by which animal detritus may benefit the invasive container-dwelling mosquito Aedesalbopictus (Skuse) (Diptera: Culicidae). In the laboratory, larvae were reared under three conditions with access to 1) detritus, but where microorganisms in the water column were reduced through periodic flushing; 2) water column microorganisms, but larvae had no direct access to detritus; or 3) both water column microorganisms and detritus. Access treatments were conducted for three masses of animal detritus: 0.005, 0.010, and 0.020 g. Water column bacterial productivity (measured via incorporation of [3H]leucine) decreased significantly with flushing and with larval presence. Removing microorganisms through flushing significantly reduced mass of adult mosquitoes (both sexes), and it significantly prolonged developmental times of females compared with treatments where water column microorganisms or microorganisms and detritus were available. Survival to adulthood was greatest when larvae had access to both water column microorganisms and 0.020 g of detritus, but it declined when only water column microorganisms were available or when 0.005 g of detritus was used. These findings indicate both direct (as a food source) and indirect (assisting with decomposition of detritus) roles of microorganisms in producing the benefit of animal detritus to container mosquito larvae. PMID:17695011

Improved Method for Determination of Respiring Individual Microorganisms in Natural Waters

PubMed Central

Tabor, Paul S.; Neihof, Rex A.

1982-01-01

A method is reported that combines the microscopic determinations of specific, individual, respiring microorganisms by the detection of electron transport system activity and the total number of organisms of an estuarine population by epifluorescence microscopy. An active cellular electron transport system specifically reduces 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT) to INT-formazan, which is recognized as opaque intracellular deposits in microorganisms stained with acridine orange. In a comparison of previously described sample preparation techniques, a loss of >70% of the counts of INT-reducing microorganisms was shown to be due to the dissolution of INT-formazan deposits by immersion oil (used in microscopy). In addition, significantly fewer fluorescing microorganisms and INT-formazan deposits, both ≤0.2 μm in size, were found for sample preparations that included a Nuclepore filter. Visual clarity was enhanced, and significantly greater direct counts and counts of INT-reducing microorganisms were recognized by transferring microorganisms from a filter to a gelatin film on a cover glass, followed by coating the sample with additional gelatin to produce a transparent matrix. With this method, the number of INT-reducing microorganisms determined for a Chesapeake Bay water sample was 2-to 10-fold greater than the number of respiring organisms reported previously for marine or freshwater samples. INT-reducing microorganisms constituted 61% of the total direct counts determined for a Chesapeake Bay water sample. This is the highest percentage of metabolically active microorganisms of any aquatic population reported using a method which determines both total counts and specific activity. PMID:16346025

Improved method for determination of respiring individual microorganisms in natural waters.

PubMed

Tabor, P S; Neihof, R A

1982-06-01

A method is reported that combines the microscopic determinations of specific, individual, respiring microorganisms by the detection of electron transport system activity and the total number of organisms of an estuarine population by epifluorescence microscopy. An active cellular electron transport system specifically reduces 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT) to INT-formazan, which is recognized as opaque intracellular deposits in microorganisms stained with acridine orange. In a comparison of previously described sample preparation techniques, a loss of >70% of the counts of INT-reducing microorganisms was shown to be due to the dissolution of INT-formazan deposits by immersion oil (used in microscopy). In addition, significantly fewer fluorescing microorganisms and INT-formazan deposits, both

Mixed convection flow of a nanofluid containing gyrotactic microorganisms over a stretching/shrinking sheet in the presence of magnetic field

NASA Astrophysics Data System (ADS)

Aman, Fazlina; Mohamad Khazim, Wan Nor Hafizah Wan; Mansur, Syahira

2017-09-01

Interaction of motile microorganisms and nanoparticles along with buoyancy forces will produce nanofluid bioconvection. Bioconvection happened because of the microorganisms are imposed into the nanofluid to stabilize the nanoparticles to suspend. In this paper, we investigated the problem of mixed convection flow of a nanofluid combined with gyrotactic microorganisms over a stretching/shrinking sheet under the influence of magnetic field. The nonlinear partial differential equations are transformed into a set of five similarities nonlinear ordinary differential equations by using similarity transformation, before being solved numerically. Some of the governing parameters involve in this problem are magnetic parameter, stretching/shrinking parameter, Brownian motion parameter, thermophoresis parameter and Prandtl number. Using tables and graphs, the consequences of numerous parameters on the flow and heat transfer features are examined and discussed. The results indicate that the skin friction coefficient, local Nusselt number, local Sherwood number and local density of the motile microorganisms are strongly affected by the governing parameters.

[Ants as carriers of microorganisms in hospital environments].

PubMed

Pereira, Rogério Dos Santos; Ueno, Mariko

2008-01-01

Concern exists regarding the real possibility of public health threats caused by pathogenic agents that are carried by urban ants. The present study had the objective of isolating and identifying the microorganisms that are associated with ants in hospital environments. One hundred and twenty-five ants of the same species were collected from different units of a university hospital. Each ant was collected using a swab soaked with physiological solution and was transferred to a tube containing brain heart infusion broth and incubated at 35 degrees C for 24 hours. From each tube, with growth, inoculations were made into specific culturing media, to isolate any microorganisms. The ants presented a high capacity for carrying microorganism groups: spore-producing Gram-positive bacilli 63.5%, Gram-negative bacilli 6.3%, Gram-positive cocci 23.1%, filamentous fungi 6.7% and yeast 0.5%. Thus, it can be inferred that ants may be one of the agents responsible for disseminating microorganisms in hospital environments.

Vermicomposting of industrially produced woodchips and sewage sludge utilizing Eisenia fetida.

PubMed

Maboeta, M S; van Rensburg, L

2003-10-01

Adult Eisenia fetida were used to vermicompost woodchips (WC) and sewage sludge (SS) that are produced as waste product by platinum mines. The aims of the study were to examine the growth and reproductive success of the worms over 84 days to determine long-term feasibility of large-scale implementation and monitor the bioconcentration of heavy metals and the effects of microorganisms inoculation to quantify possible environmental implications. Results revealed that there were no effects on growth (P>0.05), reproductive success decreased (P<0.05), and aluminum (Al), copper (Cu), and nickel (Ni) were bioconcentrated (P<0.05) in the treatment groups without an inoculate. Earthworms in the treatment group with the microorganism inoculate manifested no effects on growth or reproductive success and did not accumulate Al, Cu, and Ni. It is concluded that the only economically feasible way to bioconvert WC and SS to a potential ameliorant of platinum mine tailings would be with the addition of a microorganism inoculate.

Production of poly-beta-hydroxybutyric acid by microorganisms accumulated from river water using a two-stage perfusion culture system.

PubMed

Morimoto, T; Tashiro, F; Nagashima, H; Nishizawa, K; Nagata, F; Yokogawa, Y; Suzuki, T

2000-01-01

The perfusion culture system using a shaken ceramic membrane flask (SCMF) was employed to accumulate microorganisms separated from river water and to produce poly-beta-hydroxybutyric acid (PHB). Using a two-step culture method with a single SCMF, river microorganisms were cultured by separately feeding four representative carbon sources, n-propanol, lactic acid, methanol, and formic acid. After 140 h culture, the cell concentration and PHB content respectively reached 43 g/l and 35% when a propanol medium was fed. Using a two-stage perfusion culture with twin SCMFs, the seed cell mass was increased in the first SCMF and then supplied to the second flask for PHB production. As a consequence, the cellular PHB content rose to 51% in the second SCMF, while the cell concentration gradually increased to 25 g/l after 175 h perfusion culture. These results demonstrated the utility of the two-stage perfusion culture system for developing a cheap means of producing PHB coincident with wastewater treatment.

Use of highly alkaline conditions to improve cost-effectiveness of algal biotechnology.

PubMed

Canon-Rubio, Karen A; Sharp, Christine E; Bergerson, Joule; Strous, Marc; De la Hoz Siegler, Hector

2016-02-01

Phototrophic microorganisms have been proposed as an alternative to capture carbon dioxide (CO2) and to produce biofuels and other valuable products. Low CO2 absorption rates, low volumetric productivities, and inefficient downstream processing, however, currently make algal biotechnology highly energy intensive, expensive, and not economically competitive to produce biofuels. This mini-review summarizes advances made regarding the cultivation of phototrophic microorganisms at highly alkaline conditions, as well as other innovations oriented toward reducing the energy input into the cultivation and processing stages. An evaluation, in terms of energy requirements and energy return on energy invested, is performed for an integrated high-pH, high-alkalinity growth process that uses biofilms. Performance in terms of productivity and expected energy return on energy invested is presented for this process and is compared to previously reported life cycle assessments (LCAs) for systems at near-neutral pH. The cultivation of alkaliphilic phototrophic microorganisms in biofilms is shown to have a significant potential to reduce both energy requirements and capital costs.

Polyesters from microorganisms.

PubMed

Kim, Y B; Lenz, R W

2001-01-01

Bacterial polyesters have been found to have useful properties for applications as thermoplastics, elastomers, and adhesives and are biodegradable and biocompatible. Poly(3-hydroxyalkanoates) (PHAs) and poly(beta-malate) are the most representative polyesters synthesized by microorganisms. PHAs containing a wide variety of repeating units can be produced by bacteria, including those containing many types of pendant functional groups which can be synthesized by microorganisms that are grown on unnatural organic substrates. Poly(beta-malate) is of interest primarily for medical applications, especially for drug delivery systems. In this chapter, the bacterial production and properties of poly(3-hydroxyalkanoates) and poly(beta-malate) are described with emphasis on the former.

Rediscovering Acetate Metabolism: Its Potential Sources and Utilization for Biobased Transformation into Value-Added Chemicals.

PubMed

Lim, Hyun Gyu; Lee, Ji Hoon; Noh, Myung Hyun; Jung, Gyoo Yeol

2018-04-25

One of the great advantages of microbial fermentation is the capacity to convert various carbon compounds into value-added chemicals. In this regard, there have been many efforts to engineer microorganisms to facilitate utilization of abundant carbon sources. Recently, the potential of acetate as a feedstock has been discovered; efforts have been made to produce various biochemicals from acetate based on understanding of its metabolism. In this review, we discuss the potential sources of acetate and summarized the recent progress to improve acetate utilization with microorganisms. Furthermore, we also describe representative studies that engineered microorganisms for the production of biochemicals from acetate.

Compositions containing amino acids, phosphate and manganese and their uses

DOEpatents

Daly, Michael J.; Gaidamakova, Elena K.

2016-01-12

The invention provides methods of producing vaccines directed against microorganisms, with the methods comprising culturing, harvesting and/or suspending the microorganism in the presence of a radiation-protective composition and irradiating the bacteria or viruses with a dose of radiation sufficient to render the microorganism replication-deficient and/or non-infective. The radiation-protective compositions used in the methods of the present invention comprise at least one nucleoside, at least one antioxidant and at least one small peptide. The invention also provides methods of rendering bacteria in culture resistant to ionizing radiation (IR), with these methods comprising culturing the bacteria in the presence of a radiation-protective composition.

Compositions containing amino acids, phosphate and manganese and their uses

DOEpatents

Daly, Michael J.; Gaidamakova, Elena K.

2017-09-12

The invention provides methods of producing vaccines directed against microorganisms, with the methods comprising culturing, harvesting and/or suspending the microorganism in the presence of a radiation-protective composition and irradiating the bacteria or viruses with a dose of radiation sufficient to render the microorganism replication-deficient and/or non-infective. The radiation-protective compositions used in the methods of the present invention comprise at least one nucleoside, at least one antioxidant and at least one small peptide. The invention also provides methods of rendering bacteria in culture resistant to ionizing radiation (IR), with these methods comprising culturing the bacteria in the presence of a radiation-protective composition.

Biomediated continuous release phosphate fertilizer

DOEpatents

Goldstein, Alan H.; Rogers, Robert D.

1999-01-01

A composition is disclosed for providing phosphate fertilizer to the root zone of plants. The composition comprises a microorganism capable of producing and secreting a solubilization agent, a carbon source for providing raw material for the microorganism to convert into the solubilization agent, and rock phosphate ore for providing a source of insoluble phosphate that is solubilized by the solubilization agent and released as soluble phosphate. The composition is provided in a physical form, such as a granule, that retains the microorganism, carbon source, and rock phosphate ore, but permits water and soluble phosphate to diffuse into the soil. A method of using the composition for providing phosphate fertilizer to plants is also disclosed.

Quaternary ammonium compounds: an alternative disinfection method for fresh produce wash water.

PubMed

Chaidez, Cristobal; Lopez, Javier; Castro-del Campo, Nohelia

2007-06-01

Irrigation water can serve as a vehicle for transporting pathogenic microorganisms, and numerous cases of bacterial infections from consumption of irrigated fresh produce have been reported in recent years. Chlorine-based disinfectants applied when produce is packed are widely used to control microorganisms. When applied properly, the chlorine products are effective. However, hazardous disinfection breakdown products can be formed, and chlorine disinfectants have high oxidant activity that can affect produce quality and pose a risk to food handlers. Quaternary Ammonium Compounds (QACs) are a disinfectant alternative for the washing of fruits and vegetables. They can control a great number of microorganisms, have low toxicity when used at recommended doses, and are stable in storage. The purpose of this work was to assess the disinfectant activity of QACs against Escherichia coli and Staphylococcus aureus under worst-case and average-case turbidity conditions, (2 and 100 nephelometric units); two disinfectant concentrations (100 and 200 mg/L; and two contact times (30 and 120 seconds). Our research showed that QACs were effective against both bacteria. The percentage reduction of Escherichia coli was significantly higher in the less turbid solution (P = 0.027), while turbidity did not affect the reduction of Staphylococcus aureus (P > 0.05). E. coli was more resistant to QAC treatment than S. aureus. Based on the data obtained we can conclude that QACs could be an alternative in washing processes of fruits and vegetables.

Detoxification of biomass derived acetate via metabolic conversion to ethanol, acetone, isopropanol, or ethyl acetate

DOEpatents

Sillers, William Ryan; Van Dijken, Hans; Licht, Steve; Shaw, IV, Arthur J.; Gilbert, Alan Benjamin; Argyros, Aaron; Froehlich, Allan C.; McBride, John E.; Xu, Haowen; Hogsett, David A.; Rajgarhia, Vineet B.

2017-03-28

One aspect of the invention relates to a genetically modified thermophilic or mesophilic microorganism, wherein a first native gene is partially, substantially, or completely deleted, silenced, inactivated, or down-regulated, which first native gene encodes a first native enzyme involved in the metabolic production of an organic acid or a salt thereof, thereby increasing the native ability of said thermophilic or mesophilic microorganism to produce lactate or acetate as a fermentation product. In certain embodiments, the aforementioned microorganism further comprises a first non-native gene, which first non-native gene encodes a first non-native enzyme involved in the metabolic production of lactate or acetate. Another aspect of the invention relates to a process for converting lignocellulosic biomass to lactate or acetate, comprising contacting lignocellulosic biomass with a genetically modified thermophilic or mesophilic microorganism.

Diverse antimicrobial interactions of halophilic archaea and bacteria extend over geographical distances and cross the domain barrier

PubMed Central

Atanasova, Nina S; Pietilä, Maija K; Oksanen, Hanna M

2013-01-01

The significance of antimicrobial substances, halocins, produced by halophilic archaea and bacteria thriving in hypersaline environments is relatively unknown. It is suggested that their production might increase species diversity and give transient competitive advances to the producer strain. Halocin production is considered to be common among halophilic archaea, but there is a lack of information about halocins produced by bacteria in highly saline environments. We studied the antimicrobial activity of 68 halophilic archaea and 22 bacteria isolated from numerous geographically distant hypersaline environments. Altogether 144 antimicrobial interactions were found between the strains and aside haloarchaea, halophilic bacteria from various genera were identified as halocin producers. Close to 80% of the interactions were detected between microorganisms from different genera and in few cases, even across the domain boundary. Several of the strains produced halocins with a wide inhibitory spectrum as has been observed before. Most of the antimicrobial interactions were found between strains from distant sampling sites indicating that hypersaline environments around the world have similar microorganisms with the potential to produce wide activity range antimicrobials. PMID:23929527

Multifunctional properties of phosphate-solubilizing microorganisms grown on agro-industrial wastes in fermentation and soil conditions.

PubMed

Vassileva, Maria; Serrano, Mercedes; Bravo, Vicente; Jurado, Encarnación; Nikolaeva, Iana; Martos, Vanessa; Vassilev, Nikolay

2010-02-01

One of the most studied approaches in solubilization of insoluble phosphates is the biological treatment of rock phosphates. In recent years, various techniques for rock phosphate solubilization have been proposed, with increasing emphasis on application of P-solubilizing microorganisms. The P-solubilizing activity is determined by the microbial biochemical ability to produce and release metabolites with metal-chelating functions. In a number of studies, we have shown that agro-industrial wastes can be efficiently used as substrates in solubilization of phosphate rocks. These processes were carried out employing various technologies including solid-state and submerged fermentations including immobilized cells. The review paper deals critically with several novel trends in exploring various properties of the above microbial/agro-wastes/rock phosphate systems. The major idea is to describe how a single P-solubilizing microorganism manifests wide range of metabolic abilities in different environments. In fermentation conditions, P-solubilizing microorganisms were found to produce various enzymes, siderophores, and plant hormones. Further introduction of the resulting biotechnological products into soil-plant systems resulted in significantly higher plant growth, enhanced soil properties, and biological (including biocontrol) activity. Application of these bio-products in bioremediation of disturbed (heavy metal contaminated and desertified) soils is based on another important part of their multifunctional properties.

House hold unit for the treatment of fluoride, iron, arsenic and microorganism contaminated drinking water.

PubMed

Dhadge, Vijaykumar L; Medhi, Chitta Ranjan; Changmai, Murchana; Purkait, Mihir Kumar

2018-05-01

A first of its kind hybrid electrocoagulation-filtration prototype unit was fabricated for the removal of fluoride, iron, arsenic and microorganisms contaminated drinking water. The unit comprised of 3 chambers, chamber A consisting of an inlet for the water to be treated and an outlet for the treated water along with one block of aluminum electrodes. Chamber B consisted of ceramic membrane filtration assembly at the bottom over a metallic support which filters the flocs so produced in chamber A and chamber C consisting of space to collect the treated water. Operating parameters were maintained as current density of 625 A m -2 and an electrode distance of 0.005 m. Contaminated drinking water containing mixture of fluoride (10 mg L -1 ), iron (25 mg L -1 ), arsenic (200 μg L -1 ) and microorganisms (35 CFU ml -1 ) was used for the experiment. A removal of 98.74%, 95.65%, 93.2% and 100% were obtained for iron, arsenic, fluoride and microorganisms, respectively. The apparatus and method made it possible to efficiently treat contaminated drinking water to produce drinkable water as per WHO specification. By-products obtained from the electrocoagulation bath were analyzed using SEM, EDX and XRD and explained. Copyright © 2018 Elsevier Ltd. All rights reserved.

Marine Microorganism: An Underexplored Source of l-Asparaginase.

PubMed

Prihanto, A A; Wakayama, M

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. © 2016 Elsevier Inc. All rights reserved.

Exopolysaccharides from extremophiles: from fundamentals to biotechnology.

PubMed

Nicolaus, Barbara; Kambourova, Margarita; Oner, Ebru Toksoy

2010-09-01

Exopolysaccharides (EPSs) make up a substantial component of the extracellular polymers surrounding most microbial cells in extreme environments like Antarctic ecosystems, saline lakes, geothermal springs or deep sea hydrothermal vents. The extremophiles have developed various adaptations, enabling them to compensate for the deleterious effects of extreme conditions, e.g. high temperatures, salt, low pH or temperature, high radiation. Among these adaptation strategies, EPS biosynthesis is one of the most common protective mechanisms. The unusual metabolic pathways revealed in some extremophiles raised interest in extremophilic microorganisms as potential producers of EPSs with novel and unusual characteristics and functional activities under extreme conditions. Even though the accumulated knowledge on the structural and theological properties of EPSs from extremophiles is still very limited, it reveals a variety in properties, which may not be found in more traditional polymers. Both extremophilic microorganisms and their EPSs suggest several biotechnological advantages, like short fermentation processes for thermophiles and easily formed and stable emulsions of EPSs from psychrophiles. Unlike mesophilic producers of EPSs, many of them being pathogenic, extremophilic microorganisms provide non-pathogenic products, appropriate for applications in the food, pharmaceutical and cosmetics industries as emulsifiers, stabilizers, gel agents, coagulants, thickeners and suspending agents. The commercial value of EPSs synthesized by microorganisms from extreme habitats has been established recently.

Emergence of antibiotic-resistant extremophiles (AREs).

PubMed

Gabani, Prashant; Prakash, Dhan; Singh, Om V

2012-09-01

Excessive use of antibiotics in recent years has produced bacteria that are resistant to a wide array of antibiotics. Several genetic and non-genetic elements allow microorganisms to adapt and thrive under harsh environmental conditions such as lethal doses of antibiotics. We attempt to classify these microorganisms as antibiotic-resistant extremophiles (AREs). AREs develop strategies to gain greater resistance to antibiotics via accumulation of multiple genes or plasmids that harbor genes for multiple drug resistance (MDR). In addition to their altered expression of multiple genes, AREs also survive by producing enzymes such as penicillinase that inactivate antibiotics. It is of interest to identify the underlying molecular mechanisms by which the AREs are able to survive in the presence of wide arrays of high-dosage antibiotics. Technologically, "omics"-based approaches such as genomics have revealed a wide array of genes differentially expressed in AREs. Proteomics studies with 2DE, MALDI-TOF, and MS/MS have identified specific proteins, enzymes, and pumps that function in the adaptation mechanisms of AREs. This article discusses the molecular mechanisms by which microorganisms develop into AREs and how "omics" approaches can identify the genetic elements of these adaptation mechanisms. These objectives will assist the development of strategies and potential therapeutics to treat outbreaks of pathogenic microorganisms in the future.

Isolation and characterization of new facultative alkaliphilic Bacillus flexus strains from maize processing waste water (nejayote).

PubMed

Sanchez-Gonzalez, M; Blanco-Gamez, A; Escalante, A; Valladares, A G; Olvera, C; Parra, R

2011-04-01

This work describes the isolation and characterization of two new alkaliphilic micro-organisms present in nejayote. Samples of fresh industrial nejayote were plated on nejayote medium and incubated for 4 days at 37 °C. Isolates were identified based on morphological and physiological characteristics, as well as 16S rDNA sequence analysis. Two gram-positive strains, NJY2 and NJY4, able to hydrolyse starch, xylan, and gelatin were isolated from nejayote. Comparative sequence analysis of 16S rDNA and phylogenetic studies indicate that the micro-organisms studied were closely related to members of the Bacillus flexus species. The strains were identified as facultative alkaliphilic salt tolerant bacteria. Isolate NJY2 produced cell associated phenolic acid esterases, able to release ferulic acid from nixtamalised corn bran and ethyl and methyl esters. The isolated strains of B. flexus NJY2 and NJY4 showed important physiological properties to produce high-value molecules from agroindustrial by-products. This is the first report about the isolation of alkaliphilic micro-organisms from nejayote and the first report of phenolic acid esterases synthesised by alkaliphiles. The new alkaliphilic micro-organisms have potential application in the treatment and transformation of tortilla industry residues. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

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.

Microbial Profile of Soil-Free versus In-Soil Grown Lettuce and Intervention Methodologies to Combat Pathogen Surrogates and Spoilage Microorganisms on Lettuce

PubMed Central

Sirsat, Sujata A.; Neal, Jack A.

2013-01-01

Aquaponics is an effective method to practice sustainable agriculture and is gaining popularity in the US; however, the microbial safety of aquaponically grown produce needs to be ascertained. Aquaponics is a unique marriage of fish production and soil-free produce (e.g., leafy greens) production. Fish are raised in fresh water tanks that are connected to water filled beds where fruits and vegetables are grown. The fish bi-products create nutrient-rich water that provides the key elements for the growth of plants and vegetables. The objective of this study was to perform a comparative analysis of the microbial safety and quality of aquaponic lettuce and soil grown lettuce (conventional, bagged, certified organic, and field lettuce). Following this, an intervention study was performed to combat foodborne pathogen surrogates (Salmonella and E. coli), spoilage, and fecal microorganisms using 2.5% acetic acid. The results of the comparative analysis study showed that aquaponically grown lettuce had significantly lower concentration of spoilage and fecal microorganisms compared to in-soil grown lettuce. The intervention study showed that diluted vinegar (2.5% acetic acid) significantly reduced Salmonella, E. coli, coliforms, and spoilage microorganisms on fresh lettuce by 2 to 3 log CFU/g. Irrespective of growing methods (in-soil or soilless), it is crucial to incorporate good agricultural practices to reduce microbial contamination on fresh produce. The intervention employed in this study can be proposed to small farmers and consumers to improve quality and safety of leafy greens. PMID:28239132

Microbial Profile of Soil-Free versus In-Soil Grown Lettuce and Intervention Methodologies to Combat Pathogen Surrogates and Spoilage Microorganisms on Lettuce.

PubMed

Sirsat, Sujata A; Neal, Jack A

2013-11-11

Aquaponics is an effective method to practice sustainable agriculture and is gaining popularity in the US; however, the microbial safety of aquaponically grown produce needs to be ascertained. Aquaponics is a unique marriage of fish production and soil-free produce (e.g., leafy greens) production. Fish are raised in fresh water tanks that are connected to water filled beds where fruits and vegetables are grown. The fish bi-products create nutrient-rich water that provides the key elements for the growth of plants and vegetables. The objective of this study was to perform a comparative analysis of the microbial safety and quality of aquaponic lettuce and soil grown lettuce (conventional, bagged, certified organic, and field lettuce). Following this, an intervention study was performed to combat foodborne pathogen surrogates ( Salmonella and E. coli ), spoilage, and fecal microorganisms using 2.5% acetic acid. The results of the comparative analysis study showed that aquaponically grown lettuce had significantly lower concentration of spoilage and fecal microorganisms compared to in-soil grown lettuce. The intervention study showed that diluted vinegar (2.5% acetic acid) significantly reduced Salmonella , E. coli , coliforms, and spoilage microorganisms on fresh lettuce by 2 to 3 log CFU/g. Irrespective of growing methods (in-soil or soilless), it is crucial to incorporate good agricultural practices to reduce microbial contamination on fresh produce. The intervention employed in this study can be proposed to small farmers and consumers to improve quality and safety of leafy greens.

Screening of cloud microorganisms isolated at the Puy de Dôme (France) station for the production of biosurfactants

NASA Astrophysics Data System (ADS)

Renard, Pascal; Canet, Isabelle; Sancelme, Martine; Wirgot, Nolwenn; Deguillaume, Laurent; Delort, Anne-Marie

2016-09-01

A total of 480 microorganisms collected from 39 clouds sampled at the Puy de Dôme station (alt. 1465 m; 45°46'19'' N, 2°57'52'' E; Massif Central, France) were isolated and identified. This unique collection was screened for biosurfactant (surfactants of microbial origin) production by measuring the surface tension (σ) of the crude extracts, comprising the supernatants of the pure cultures, using the pendant drop technique. The results showed that 41 % of the tested strains were active producers (σ < 55 mN m-1), with 7 % being extremely active (σ < 30 mN m-1). The most efficient biosurfactant producers (σ < 45 mN m-1) belong to a few bacterial genera (Pseudomonas and Xanthomonas) from the Υ-Proteobacteria class (78 %) and a yeast genus (Udeniomyces) from the Basidiomycota phylum (11 %). Some Bacillus strains from the Firmicutes phylum were also active but represented a small fraction of the collected population. Strains from the Actinobacteria phylum in the collection examined in the present study showed moderate biosurfactant production (45<σ < 55 mN m-1). Pseudomonas (Υ-Proteobacteria), the most frequently detected genus in clouds, with some species issued from the phyllosphere, was the dominant group for the production of biosurfactants. We observed some correlations between the chemical composition of cloud water and the presence of biosurfactant-producing microorganisms, suggesting the "biogeography" of this production. Moreover, the potential impact of the production of biosurfactants by cloud microorganisms on atmospheric processes is discussed.

Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels.

PubMed

Lee, Sung Kuk; Chou, Howard; Ham, Timothy S; Lee, Taek Soon; Keasling, Jay D

2008-12-01

The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels. Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity (e.g. maximum butanol production is around 20 g/L). For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology will provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.

Pathway Design, Engineering, and Optimization.

PubMed

Garcia-Ruiz, Eva; HamediRad, Mohammad; Zhao, Huimin

The microbial metabolic versatility found in nature has inspired scientists to create microorganisms capable of producing value-added compounds. Many endeavors have been made to transfer and/or combine pathways, existing or even engineered enzymes with new function to tractable microorganisms to generate new metabolic routes for drug, biofuel, and specialty chemical production. However, the success of these pathways can be impeded by different complications from an inherent failure of the pathway to cell perturbations. Pursuing ways to overcome these shortcomings, a wide variety of strategies have been developed. This chapter will review the computational algorithms and experimental tools used to design efficient metabolic routes, and construct and optimize biochemical pathways to produce chemicals of high interest.

Towards systems metabolic engineering of microorganisms for amino acid production.

PubMed

Park, Jin Hwan; Lee, Sang Yup

2008-10-01

Microorganisms capable of efficient production of amino acids have traditionally been developed by random mutation and selection method, which might cause unwanted physiological changes in cellular metabolism. Rational genome-wide metabolic engineering based on systems and synthetic biology tools, which is termed 'systems metabolic engineering', is rising as an alternative to overcome these problems. Recently, several amino acid producers have been successfully developed by systems metabolic engineering, where the metabolic engineering procedures were performed within a systems biology framework, and entire metabolic networks, including complex regulatory circuits, were engineered in an integrated manner. Here we review the current status of systems metabolic engineering successfully applied for developing amino acid producing strains and discuss future prospects.

Effects of beneficial microorganisms on lowland rice development.

PubMed

Nascente, Adriano Stephan; de Filippi, Marta Cristina Corsi; Lanna, Anna Cristina; de Sousa, Thatyane Pereira; de Souza, Alan Carlos Alves; da Silva Lobo, Valácia Lemes; da Silva, Gisele Barata

2017-11-01

Microorganisms can promote plant growth by increasing phytomass production, nutrient uptake, photosynthesis rates, and grain yield, which can result in higher profits for farmers. However, there is limited information available about the physiological characteristics of lowland rice after treatment with beneficial microorganisms in the tropical region. This study aimed to determine the effects of different beneficial microorganisms and various application forms on phytomass production, gas exchange, and nutrient contents in the lowland rice cultivar 'BRS Catiana' in a tropical region. The experiment was performed under greenhouse conditions utilizing a completely randomized design and a 7 × 3 + 1 factorial scheme with four replications. The treatments consisted of seven microorganisms, including the rhizobacterial isolates BRM 32113, BRM 32111, BRM 32114, BRM 32112, BRM 32109, and BRM 32110 and Trichoderma asperellum pooled isolates UFRA-06, UFRA-09, UFRA-12, and UFRA-52, which were applied using three different methods (microbiolized seed, microbiolized seed + soil drenched with a microorganism suspension at 7 and 15 days after sowing (DAS), and microbiolized seed + plant spraying with a microorganism suspension at 7 and 15 DAS) with a control (water). The use of microorganisms can provide numerous benefits for rice in terms of crop growth and development. The microorganism types and methods of application positively and differentially affected the physiological characteristics evaluated in the experimental lowland rice plants. Notably, the plants treated with the bioagent BRM 32109 on the seeds and on seeds + soil produced plants with the highest dry matter biomass, gas exchange rate, and N, P, Fe, and Mg uptake. Therefore, our findings indicate strong potential for the use of microorganisms in lowland rice cultivation systems in tropical regions. Currently, an additional field experiment is in its second year to validate the beneficial result reported here and the novel input sustainability.

Generation of PHB from Spent Sulfite Liquor Using Halophilic Microorganisms.

PubMed

Weissgram, Michaela; Gstöttner, Janina; Lorantfy, Bettina; Tenhaken, Raimund; Herwig, Christoph; Weber, Hedda K

2015-06-08

Halophilic microorganisms thrive at elevated concentrations of sodium chloride up to saturation and are capable of growing on a wide variety of carbon sources like various organic acids, hexose and also pentose sugars. Hence, the biotechnological application of these microorganisms can cover many aspects, such as the treatment of hypersaline waste streams of different origin. Due to the fact that the high osmotic pressure of hypersaline environments reduces the risk of contamination, the capacity for cost-effective non-sterile cultivation can make extreme halophilic microorganisms potentially valuable organisms for biotechnological applications. In this contribution, the stepwise use of screening approaches, employing design of experiment (DoE) on model media and subsequently using industrial waste as substrate have been implemented to investigate the applicability of halophiles to generate PHB from the industrial waste stream spent sulfite liquor (SSL). The production of PHB on model media as well as dilutions of industrial substrate in a complex medium has been screened for by fluorescence microscopy using Nile Blue staining. Screening was used to investigate the ability of halophilic microorganisms to withstand the inhibiting substances of the waste stream without negatively affecting PHB production. It could be shown that neither single inhibiting substances nor a mixture thereof inhibited growth in the investigated range, hence, leaving the question on the inhibiting mechanisms open. However, it could be demonstrated that some haloarchaea and halophilic bacteria are able to produce PHB when cultivated on 3.3% w/w dry matter spent sulfite liquor, whereas H. halophila was even able to thrive on 6.6% w/w dry matter spent sulfite liquor and still produce PHB.

Activation of inoculum microorganism from dairy cattle feces

NASA Astrophysics Data System (ADS)

Ayuningtyas, Widya D.; Ridwan, Roni; Joni, I. M.; Marlina, E. T.; Harlia, Ellin

2018-02-01

Coal produces Coal Bed Methane (CBM) which is formed both biogenically and thermogenically. Lignite is not utilized optimally because it has low heat content and productivity time limit that decreases CBM production. In order to utilize lignite waste, adding inoculum consortium microorganism from dairy cattle waste as starter for biogas process can be a solution. This study aimed to produce inoculum consortium microorganism as biogas starter from dairy cattle feces through in vitro activation process by Theoudorou modification method. The research used complete randomized design with 3 replications. The treatments were blank (R0), 100% concentrate (R1), 70% concentrate+30% grass (R2), 70% grass+30% concentrate (R3) and 100% grass (R4). All treatments were added by buffer solution and feces with ratio of 2:1 into 100 ml serum injection bottle with anaerobic conditions. The parameters observed were gas production, pH and gas kinetics (orskov's equation) for 2, 4, 6, 8, 10, 12, 24 and 48 hours. The results showed that the treatment had significant effect (P <0.05) on the observed parameters. The highest total gas production was for R2 and R3 treatments with total production of 91.17 ml and 101.17 ml, pH (6.62 and 6.57), maximum gas production (94.03 and 97.62 ml), speed of gas production (0.066 and 0.084 ml/hour). There is not a significant difference for both the treatments. The source of inoculum consortium microorganisms for biogas starter selected based on the observed parameters and potential availability of proteolytic and fibrocytic microorganisms is R2 (70% concentrate +30% grass).

Isolation of amylolytic, xylanolytic, and cellulolytic microorganisms extracted from the gut of the termite Reticulitermes santonensis by means of a micro-aerobic atmosphere.

PubMed

Tarayre, Cédric; Brognaux, Alison; Bauwens, Julien; Brasseur, Catherine; Mattéotti, Christel; Millet, Catherine; Destain, Jacqueline; Vandenbol, Micheline; Portetelle, Daniel; De Pauw, Edwin; Eric, Haubruge; Francis, Frédéric; Thonart, Philippe

2014-05-01

The aim of this work was to isolate enzyme-producing microorganisms from the tract of the termite Reticulitermes santonensis. The microorganisms were extracted from the guts and anaerobic (CO₂ or CO₂/H₂) and micro-aerobic atmospheres were used to stimulate growth. Three different strategies were tried out. First, the sample was spread on Petri dishes containing solid media with carboxymethylcellulose, microcrystalline cellulose or cellobiose. This technique allowed us to isolate two bacteria: Streptomyces sp. strain ABGxAviA1 and Pseudomonas sp. strain ABGxCellA. The second strategy consisted in inoculating a specific liquid medium containing carboxymethylcellulose, microcrystalline cellulose, or cellobiose. The samples were then spread on Petri dishes with the same specific medium containing carboxymethylcellulose, microcrystalline cellulose, or cellobiose. This led to the isolation of the mold Aspergillus sp. strain ABGxAviA2. Finally, the third strategy consisted in heating the first culture and spreading samples on agar plates containing rich medium. This led to the isolation of the bacterium Bacillus subtilis strain ABGx. All those steps were achieved in controlled atmospheres. The four enzyme-producing strains which were isolated were obtained by using a micro-aerobic atmosphere. Later, enzymatic assays were performed on the four strains. Streptomyces sp. strain ABGxAviA1 was found to produce only amylase, while Pseudomonas sp. strain ABGxCellA was found to produce β-glucosidase as well. Aspergillus sp. strain ABGxAviA2 showed β-glucosidase, amylase, cellulase, and xylanase activities. Finally, B. subtilis strain ABGx produced xylanase and amylase.

The use of controlled microbial cenoses in producers' link to increase steady functioning of artificial ecosystems

NASA Astrophysics Data System (ADS)

Somova, Lydia; Mikheeva, Galina; Somova, Lydia

The life support systems (LSS) for long-term missions are to use cycling-recycling systems, including biological recycling. Simple ecosystems include 3 links: producers (plants), consumers (man, animals) and reducers (microorganisms). Microorganisms are substantial component of every link of LSS. Higher plants are the traditional regenerator of air and producer of food. They should be used in many successive generations of their reproduction in LSS. Controlled microbiocenoses can increase productivity of producer's link and protect plants from infections. The goal of this work was development of methodological bases of formation of stable, controlled microbiocenoses, intended for increase of productivity of plants and for obtaining ecologically pure production of plants. Main results of our investigations: 1. Experimental microbiocenoses, has been produced in view of the developed methodology on the basis of natural association of microorganisms by long cultivation on specially developed medium. Dominating groups are bacteria of genera: Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Rhodopseudomonas and yeast of genera: Kluyveromyces, Saccharomyces, Torulopsis. 2. Optimal parameters of microbiocenosis cultivation (t, pH, light exposure, biogenic elements concentrations) were experimentally established. Conditions of cultivation on which domination of different groups of microbiocenosis have been found. 3. It was shown, that processing of seeds of wheat, oats, bulbs and plants Allium cepa L. (an onions) with microbial association raised energy of germination of seeds and bulbs and promoted the increase (on 20-30 %) of growth green biomass and root system of plants in comparison with the control. This work is supported by grant, Yenissey , 07-04-96806

A step towards on-chip biochemical energy cascade of microorganisms: carbon dioxide generation induced by ethanol fermentation in 3D printed modular lab-on-a-chip

NASA Astrophysics Data System (ADS)

Podwin, A.; Kubicki, W.; Adamski, K.; Walczak, R.; Dziuban, J. A.

2016-11-01

The concept of biochemical energy cascade of microorganisms towards oxygen generation in 3D printed lab-on-a-chip has been presented. In this work, carbon dioxide - a product of ethanol fermentation of yeasts has been utilized to enable light-initialized photosynthesis of euglenas and as a result of their metabolic transitions produce pure oxygen.

Metabolic engineering of the shikimate pathway

DOEpatents

Juminaga, Darmawi; Keasling, Jay D.

2017-01-10

The present disclosure relates to engineered microorganisms that produce amino acids and amino acid intermediates. In particular, the disclosure relates to recombinant nucleic acids encoding operons that increase production of aromatic amino acids and the aromatic amino acid intermediate shikimate; microorganisms with increased production of aromatic amino acids and the aromatic amino acid intermediate shikimate; and methods related to the production of aromatic amino acids, the aromatic amino acid intermediate shikimate, and commodity chemicals derived therefrom.

Halotolerant bacteria in the São Paulo Zoo composting process and their hydrolases and bioproducts

PubMed Central

Oliveira, Lilian C.G.; Ramos, Patricia Locosque; Marem, Alyne; Kondo, Marcia Y.; Rocha, Rafael C.S.; Bertolini, Thiago; Silveira, Marghuel A.V.; da Cruz, João Batista; de Vasconcellos, Suzan Pantaroto; Juliano, Luiz; Okamoto, Debora N.

2015-01-01

Halophilic microorganisms are able to grow in the presence of salt and are also excellent source of enzymes and biotechnological products, such as exopolysaccharides (EPSs) and polyhydroxyalkanoates (PHAs). Salt-tolerant bacteria were screened in the Organic Composting Production Unit (OCPU) of São Paulo Zoological Park Foundation, which processes 4 ton/day of organic residues including plant matter from the Atlantic Rain Forest, animal manure and carcasses and mud from water treatment. Among the screened microorganisms, eight halotolerant bacteria grew at NaCl concentrations up to 4 M. These cultures were classified based on phylogenetic characteristics and comparative partial 16S rRNA gene sequence analysis as belonging to the genera Staphylococcus, Bacillus and Brevibacterium. The results of this study describe the ability of these halotolerant bacteria to produce some classes of hydrolases, namely, lipases, proteases, amylases and cellulases, and biopolymers. The strain characterized as of Brevibacterium avium presented cellulase and amylase activities up to 4 M NaCl and also produced EPSs and PHAs. These results indicate the biotechnological potential of certain microorganisms recovered from the composting process, including halotolerant species, which have the ability to produce enzymes and biopolymers, offering new perspectives for environmental and industrial applications. PMID:26273248

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.

Co-culture-inducible bacteriocin production in lactic acid bacteria.

PubMed

Chanos, Panagiotis; Mygind, Tina

2016-05-01

It is common knowledge that microorganisms have capabilities, like the production of antimicrobial compounds, which do not normally appear in ideal laboratory conditions. Common antimicrobial discovery techniques require the isolation of monocultures and their individual screening against target microorganisms. One strategy to achieve expression of otherwise hidden antimicrobials is induction by co-cultures. In the area of bacteriocin-producing lactic acid bacteria, there has been some research focusing into the characteristics of co-culture-inducible bacteriocin production and particularly the molecular mechanism(s) of such interactions. No clear relationship has been seen between bacteriocin-inducing and bacteriocin-producing microorganisms. The three-component regulatory system seems to be playing a central role in the induction, but inducing compounds have not been identified or characterized. However, the presence of the universal messenger molecule autoinducer-2 has been associated in some cases with the co-culture-inducible bacteriocin phenotype and it may play the role in the additional regulation of the three-component regulatory system. Understanding the mechanisms of induction would facilitate the development of strategies for screening and development of co-culture bacteriocin-producing systems and novel products as well as the perseverance of such systems in food and down to the intestinal tract, possibly conferring a probiotic effect on the host.

Evaluation of the Influence That Was Produced by Phytoremediation of Soil Microorganisms at Oil Showings

NASA Astrophysics Data System (ADS)

Kaimi, Etsuko; Kawakita, Morikazu; Mukaidani, Tsukasa; Fujiwara, Kazuhiro; Okada, Shin-Ichi; Yasuda, Yoshio

Phytoremediation has been identified as a potentially environmentally friendly and cost effective technique for the treatment of contaminated soil. However, phytoremediation has an unknown mechanism. In this study, we focus on the effects of the cultivation of Italian ryegrass on the soil microbes collected at oil showings, which were expected to have a variety of crude oil degradable microorganisms. We evaluated the number of crude oil degradable microorganism, microbial activity, microflora using the PCR-DGGE method and the change in the concentration of crude oil in the soil. The results indicated that the microflora was affected by the cultivation of Itarian ryegrass, and that the microbial activity and the number of crude oil degradable microorganisms were also improved by the cultivation. Moreover, the concentration of crude oil in the rhizosphere soil decreased significantly when compared to the uncultivated soil. These results suggested that cultivation could regulate microflora selectively, which degraded crude oil.

Bioethanol production from tuber crops using fermentation technology: a review

NASA Astrophysics Data System (ADS)

Thatoi, Hrudayanath; Dash, Preeti Krishna; Mohapatra, Sonali; Swain, Manas Ranjan

2016-05-01

Bioethanol, an alcohol produced by fermentation of plant biomass containing starch and sugars by micro-organisms, considered as a dominant form of fuel for future. Production of this renewable fuel, especially from starchy materials such as tuber crops, holds a remarkable potential to meet the future energy demand because of its high production and comparitively less demand for use as food and fodder. This review focuses on the world bioethanol production scenario from various tuber crops, namely cassava, sweet potato, potato, yam, aroids, sugar beet, etc., fermentation techniques and micro-organisms used in fermentation process along with its future prospects. The advances in metabolic pathway engineering and genetic engineering techniques have led to the development of micro-organisms capable of efficiently converting biomass sugars into ethanol. Several biotechnological tools that are also available for the improvement of microorganisms to meet the harsh environments typically met with certain industrial fermentation process are also discussed.

Flavor evaluation of yak butter in Tsinghai-Tibet Plateau and isolation of microorganisms contributing flavor.

PubMed

Hu, SongQing; Wei, HaiLiu; Guo, ShaSha; Li, Lin; Hou, Yi

2011-02-01

Yak butter in Tsinghai-Tibet Plateau possesses the characters of high energy, abundant alimentation and a special flavor with certain medical and health care functions. In this paper the organoleptic flavor of yak butter was estimated, and 28 kinds of substance with different flavors were identified with the technique of coupling gas chromatography to mass spectroscopy (GC-MS). The results showed that there are many microorganisms in yak butter with natural inoculation, which contribute to the formation of its special flavors. It was found that three of these 15 microorganisms, identified as Saccharomycetaceae, Penicillium and Asperillus separately, contributed the most to flavors. The microorganisms are expected to be applied in the food industry, especially to produce dairy food with the unique flavor of yak butter. © 2010 The Authors. Journal compilation © 2010 Japanese Society of Animal Science.

Contamination revealed by indicator microorganism levels during veal processing

USDA-ARS?s Scientific Manuscript database

The United States Department of Agriculture (USDA) Food Safety Inspection Service (FSIS) has identified a higher percentage of non-O157 Shiga toxin-producing Escherichia coli positive samples collected from veal trimmings than from products produced from other cattle slaughter classes. During site ...

Production of Ethylene and Carbon Monoxide by Microorganisms

Treesearch

T. H. Filer; L. R. Brown; S. Brown-Sarobot; S. Martin

1984-01-01

Various quantities of ethylene and carbon monoxide were produced on PDA by Fusicladium effusum, Pestilotia nucicola, Alternaria tenuis, and Fusarium oxysporum subcultured from diseased pecan shucks. Repeated subculturing of these fungi on potato dextrose broth supplemented with iron powder produced ethylene. The production of...

A SAFE consortium position paper: Update on microbial safety of fresh produce

USDA-ARS?s Scientific Manuscript database

Surveys of fresh produce demonstrate potential to become contaminated with pathogenic microorganisms. The analysis of microbiological risk is generally divided into three categories: Risk Assessment identifies the factors that contribute to a problem; Risk Management identifies ways to solve a probl...

Biomediated continuous release phosphate fertilizer

DOEpatents

Goldstein, A.H.; Rogers, R.D.

1999-06-15

A composition is disclosed for providing phosphate fertilizer to the root zone of plants. The composition comprises a microorganism capable of producing and secreting a solubilization agent, a carbon source for providing raw material for the microorganism to convert into the solubilization agent, and rock phosphate ore for providing a source of insoluble phosphate that is solubilized by the solubilization agent and released as soluble phosphate. The composition is provided in a physical form, such as a granule, that retains the microorganism, carbon source, and rock phosphate ore, but permits water and soluble phosphate to diffuse into the soil. A method of using the composition for providing phosphate fertilizer to plants is also disclosed. 13 figs.

Comparison of biotransformation of inorganic selenium by Lactobacillus and Saccharomyces in lactic fermentation process of yogurt and kefir.

PubMed

Alzate, A; Fernández-Fernández, A; Pérez-Conde, M C; Gutiérrez, A M; Cámara, C

2008-09-24

The aim of the present study was to characterize, quantify, and compare the different selenium species that are produced when lactic fermentation with two different types of microorganisms, bacteria (Lactobacillus) and yeast (Saccharomyces), take place to produce yogurt and kefir, respectively, and to study the transformation process of these species as a function of time. These two dairy products were chosen for the study because they are highly consumed in different cultures. Moreover, the microorganisms present in the fermentation processes are different. While the bacteria Lactobacillus is the one responsible for yogurt fermentation, a partnership between bacteria and the yeast Saccharomyces causes kefir fermentation. A comparative study has been carried out by fermenting Se(IV) enriched milk in the presence of both types of microorganisms, where the concentration range studied was from 0.5 to 20 microg g (-1). Enzymatic extraction enabled selenium speciation profiles, obtained by anionic exchange and ion-pairing reversed phase high performance liquid chromatography (IP-RP-HPLC) with inductively coupled plasma mass spectrometry (ICP-MS) detection. Scanning electron microscopy (SEM) applied to the enriched samples showed segregated Se (0), at added concentrations higher than 5 microg g (-1). The main Se species formed depended on the type of microorganism involved in the fermentation process, SeCys 2 and MeSeCys being the main species generated in yogurt and SeMet in kefir. The results obtained are different for both kinds of samples. Lactic fermentation for yogurt produced an increment in selenocystine (SeCys 2) and Se-methylselenocysteine (MeSeCys), while fermentation to produce kefir also incremented the selenomethionine (SeMet) concentration. The Se species are stable for at least 10 and 15 days for kefir and yogurt, respectively. After this period, selenocystine concentration decreased, and the concentration of Se-methylselenocysteine was found to significantly increase.

Yeasts Diversity in Fermented Foods and Beverages

NASA Astrophysics Data System (ADS)

Tamang, Jyoti Prakash; Fleet, Graham H.

People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuk Lee, Sung; Chou, Howard; Ham, Timothy S.

2009-12-02

The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels. Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity (e.g. maximum butanol production is around 20 g/L). For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology willmore » provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.« less

Rhamnolipid biosurfactants: evolutionary implications, applications and future prospects from untapped marine resource.

PubMed

Kiran, George Seghal; Ninawe, Arun Shivanth; Lipton, Anuj Nishanth; Pandian, Vijayalakshmi; Selvin, Joseph

2016-01-01

Rhamnolipid-biosurfactants are known to be produced by the genus Pseudomonas, however recent literature reported that rhamnolipids (RLs) are distributed among diverse microbial genera. To integrate the evolutionary implications of rhamnosyl transferase among various groups of microorganisms, a comprehensive comparative motif analysis was performed amongst bacterial producers. Findings on new RL-producing microorganism is helpful from a biotechnological perspective and to replace infective P. aeruginosa strains which ultimately ensure industrially safe production of RLs. Halotolerant biosurfactants are required for efficient bioremediation of marine oil spills. An insight on the exploitation of marine microbes as the potential source of RL biosurfactants is highlighted in the present review. An economic production process, solid-state fermentation using agro-industrial and industrial waste would increase the scope of biosurfactants commercialization. Potential and prospective applications of RL-biosurfactants including hydrocarbon bioremediation, heavy metal removal, antibiofilm activity/biofilm disruption and greener synthesis of nanoparticles are highlighted in this review.

Urinary Infections in Patients with Catheters in the Upper Urinary Tract: Microbiological Study.

PubMed

Lara-Isla, Alba; Medina-Polo, José; Alonso-Isa, Manuel; Benítez-Sala, Raúl; Sopeña-Sutil, Raquel; Justo-Quintas, Juan; Gil-Moradillo, Javier; González-Padilla, Daniel A; García-Rojo, Esther; Passas-Martínez, Juan Bautista; Tejido-Sánchez, Ángel

2017-01-01

Infections related to catheters in the upper urinary tract (CUUT) are associated with specific characteristics. A prospective observational study was carried out from 2012 to 2015 to evaluate infections in patients with CUUT. A total of 209 infections were included (99 with double-J, 81 with nephrostomy, and 29 with internal/external nephroureteral stents). Among nephrostomy tube carriers, the most frequently isolated microorganisms were Pseudomonas and Enterococcus. In those with an internal/external nephroureteral stent, Klebsiella was the most common, and 57.1% were extended-spectrum beta-lactamase-producing Klebsiella. In double-J carriers, Escherichia coli and Enterococcus were the most common microorganisms. Multiple-drug resistance (MDR) microorganisms were isolated in 28.6, 47.1, and 58.3% of patients with double-J, nephrostomy, and internal-external nephroureteral stents. A percutaneous CUUT (p = 0.005) and immunosuppression (p = 0.034) were risk factors for MDR microorganisms. Non-E. coli bacteria are commonly isolated in patients with CUUT. MDR microorganisms are frequent, mainly in percutaneous approach or immunosuppression. © 2017 S. Karger AG, Basel.

Airborne microorganisms from waste containers.

PubMed

Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

2012-01-01

In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste.

Screening of Microorganisms Producing Cold-Active Oxidoreductases to Be Applied in Enantioselective Alcohol Oxidation. An Antarctic Survey

PubMed Central

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. PMID:21673897

Irrigation waters as a source of pathogenic microorganisms in produce: a review

USDA-ARS?s Scientific Manuscript database

There is increasing evidence that consumption of raw fresh produce is a major factor contributing to human gastrointestinal illness. A wide variety of pathogens contribute to food-borne illnesses, including bacteria (e.g., Salmonella, pathogenic E. coli), protozoa (e.g., Cryptosporidium, Giardia), ...

Metabolic regulation and overproduction of primary metabolites

PubMed Central

Sanchez, Sergio; Demain, Arnold L.

2008-01-01

Summary Overproduction of microbial metabolites is related to developmental phases of microorganisms. Inducers, effectors, inhibitors and various signal molecules play a role in different types of overproduction. Biosynthesis of enzymes catalysing metabolic reactions in microbial cells is controlled by well‐known positive and negative mechanisms, e.g. induction, nutritional regulation (carbon or nitrogen source regulation), feedback regulation, etc. The microbial production of primary metabolites contributes significantly to the quality of life. Fermentative production of these compounds is still an important goal of modern biotechnology. Through fermentation, microorganisms growing on inexpensive carbon and nitrogen sources produce valuable products such as amino acids, nucleotides, organic acids and vitamins which can be added to food to enhance its flavour, or increase its nutritive values. The contribution of microorganisms goes well beyond the food and health industries with the renewed interest in solvent fermentations. Microorganisms have the potential to provide many petroleum‐derived products as well as the ethanol necessary for liquid fuel. Additional applications of primary metabolites lie in their impact as precursors of many pharmaceutical compounds. The roles of primary metabolites and the microbes which produce them will certainly increase in importance as time goes on. In the early years of fermentation processes, development of producing strains initially depended on classical strain breeding involving repeated random mutations, each followed by screening or selection. More recently, methods of molecular genetics have been used for the overproduction of primary metabolic products. The development of modern tools of molecular biology enabled more rational approaches for strain improvement. Techniques of transcriptome, proteome and metabolome analysis, as well as metabolic flux analysis. have recently been introduced in order to identify new and important target genes and to quantify metabolic activities necessary for further strain improvement. PMID:21261849

Isolation, characterization, and metabolism of microorganisms indigenous to subterranean oil-bearing formations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azadpour, A.

This research develops information on the microflora indigenous to subterranean oil reservoirs, with special emphasis on its potential role in microbial enhanced oil recovery (MEOR). The following studies were performed: (a) to quantify and characterize the microbial species indigenous to several different oil-bearing formations, (b) to determine the ability of microbial isolates to utilize various carbons and nitrogen sources and identify by-products that may be useful in MEOR processes, (c) to determine whether sulfate-reducing bacteria are indigenous to petroleum reservoirs, (d) to determine whether ultramicrobacteria are indigenous to petroleum reservoirs, and (e) to determine the ability of indigenous microorganisms inmore » intact cores to grow with the addition of supplemental nutrients. Reservoir depth from which the 7 sample cores were obtained ranged from 805 ft to 14,596 ft., all seven cores containing viable microorganisms with ultramicrobacteria in two of the seven cores. No sulfate-reducing isolates were obtained. Results showed that the indigenous microflora of the oil reservoirs either as a pure or as a mixed microbial cultures can and will grow under anaerobic conditions and will produce substances useful in recovering oil. The cultures also colonized stratal materials to produce by-products of importance in MEOR. The addition of supplemental nitrate ions and orthophosphate ions to the injection water resulted in an increase in microbial numbers, the production of gases, and the production of acids in the effluent from the cores. These events were synchronized with release of the fine particles and the release of oil from the core. The results support the concept that microorganisms indigenous to oil-bearing formations valuable in enhancing oil recovery if properly supplied with supplemental nutrients. No adverse environmental effects will results from either using the supplemental nutrients or producing the microbial by-products.« less

Metabolic engineering of industrial platform microorganisms for biorefinery applications--optimization of substrate spectrum and process robustness by rational and evolutive strategies.

PubMed

Buschke, Nele; Schäfer, Rudolf; Becker, Judith; Wittmann, Christoph

2013-05-01

Bio-based production promises a sustainable route to myriads of chemicals, materials and fuels. With regard to eco-efficiency, its future success strongly depends on a next level of bio-processes using raw materials beyond glucose. Such renewables, i.e., polymers, complex substrate mixtures and diluted waste streams, often cannot be metabolized naturally by the producing organisms. This particularly holds for well-known microorganisms from the traditional sugar-based biotechnology, including Escherichia coli, Corynebacterium glutamicum and Saccharomyces cerevisiae which have been engineered successfully to produce a broad range of products from glucose. In order to make full use of their production potential within the bio-refinery value chain, they have to be adapted to various feed-stocks of interest. This review focuses on the strategies to be applied for this purpose which combine rational and evolutive approaches. Hereby, the three industrial platform microorganisms, E. coli, C. glutamicum and S. cerevisiae are highlighted due to their particular importance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Axenic culture of free-living conchocelis of Porphyra yezoensis and Porphyra haitanensis

NASA Astrophysics Data System (ADS)

Liu, Hui-Lian; Shuai, Li; Duan, De-Lin; Xu, Huai-Shu

2002-03-01

After discarding marine microorganisms from conchocelis of Porphyra yezoensis and Porphyra haitanensis, their axenic cultures were obtained through treatment with antibiotics. Antibiotic disc tests were carried out to determine the effectiveness of each antibiotic in eliminating contaminating microorganisms. Five of 12 antibiotics tested were selected and used to produce the axenic cultures in this study, which showed that 200 μg/mL streptomycin, 250 μg/mL penicillin, 252 μg/mL kanamycin, 30 μg/mL chloramphenicol were effective concentrations for eliminating microorganisms from conchocelis when antibiotics were added singly step by step; whereas simultaneous combination of 150 μg/mL streptomycin, 250 (or 350) μg/mL penicillin, 150 (or 250) μg/mL kanamycin, 70 μg/mL neomycin and 200 μg/mL chloramphenicol was also effective for producing the axenic cultures. However, it seemed that the treatments with antibiotics applied individually were more feasible than those will all antibiotics added at the same time. This may be due to the combined inhibiting effect of antibiotics on the growth and development of conchocelis.

Bioprospecting of lipolytic microorganisms obtained from industrial effluents.

PubMed

Peil, Greice H S; Kuss, Anelise V; Rave, Andrés F G; Villarreal, José P V; Hernandes, Yohana M L; Nascente, Patrícia S

2016-01-01

The lipases have ability to catalyze diverse reactions and are important in different biotechnological applications. The aim of this work was to isolate and characterize microorganisms that produce lipases, from different food industry effluents localized in Pelotas, RS/Brazil. Bacteria were identified using Gram stain and biochemical tests (Vitek 2(r)). Fungi were identified according to macro and micromorphology characteristics. The extracellular lipase production was evaluated using the Rhodamine B test and the enzymatic activity by titration. Twenty-one bacteria were isolated and identified as Klebsiella pneumoniae ssp. pneumoniae, Serratia marcescens, Enterobacter aerogenes, Raoultella ornithinolytica and Raoultella planticola. Were characterized isolated filamentous fungi by the following genera: Alternaria sp., Fusarium sp., Geotrichum sp., Gliocladium sp., Mucor sp., Paecilomyces sp. and Trichoderma sp. Extracellular lipase production was observed in 71.43% of the bacteria and 57.14% of the fungi. The bacterium that presented better promising enzymatic activity was E. aerogenes (1.54 U/ml) however between fungi there was not significant difference between the four isolates. This study indicated that microorganisms lipase producers are present in the industrial effluents, as well as these enzymes have potential of biodegradation of lipid compounds.

Screen of micro-organisms for inducing the production of dragon's blood by leaf of Dracaena cochinchinensis.

PubMed

Wang, X H; Zhang, C H; Wang, Y; Gomes-Laranjo, J

2010-11-01

To screen micro-organisms for inducing the production of dragon's blood, which is normally produced by stem xylem and by leaf of Dracaena cochinchinensis, and to evaluate the product by comparing with the standard. Thirty microbial strains were isolated from D. cochinchinensis leaves. Three of them were confirmed to elicit the leaf of D. cochinchinensis producing dragon's blood after inoculation. Upon elicitation, all of the 6-month-old leaves of the inducible trees produced dragon's blood; 60-70% of the 1-year-old leaves elicited produced the resin. All the three strains were identified as Colletotrichum gloeosporioide by morphological and molecular methods. The leaf resin had a similar TLC profile and antioxidant activities to the standard resin. In particular, it had a higher total flavonol content and antimicrobial activity than the standard. Upon the induction of the screened C. gloeosporioide mycelia, D. cochinchinensis leaf produced dragon's blood with higher total flavone content and antimicrobial activity than the standard dragon's blood. This work has provided a strategy for producing dragon's blood in a sustainable way using leaves of C. gloeosporioides by fungal elicitation. © 2010 The Authors. © 2010 The Society for Applied Microbiology.

Diverse antimicrobial interactions of halophilic archaea and bacteria extend over geographical distances and cross the domain barrier.

PubMed

Atanasova, Nina S; Pietilä, Maija K; Oksanen, Hanna M

2013-10-01

The significance of antimicrobial substances, halocins, produced by halophilic archaea and bacteria thriving in hypersaline environments is relatively unknown. It is suggested that their production might increase species diversity and give transient competitive advances to the producer strain. Halocin production is considered to be common among halophilic archaea, but there is a lack of information about halocins produced by bacteria in highly saline environments. We studied the antimicrobial activity of 68 halophilic archaea and 22 bacteria isolated from numerous geographically distant hypersaline environments. Altogether 144 antimicrobial interactions were found between the strains and aside haloarchaea, halophilic bacteria from various genera were identified as halocin producers. Close to 80% of the interactions were detected between microorganisms from different genera and in few cases, even across the domain boundary. Several of the strains produced halocins with a wide inhibitory spectrum as has been observed before. Most of the antimicrobial interactions were found between strains from distant sampling sites indicating that hypersaline environments around the world have similar microorganisms with the potential to produce wide activity range antimicrobials. © 2013 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Culture medium optimization for acetic acid production by a persimmon vinegar-derived bacterium.

PubMed

Kim, Jin-Nam; Choo, Jong-Sok; Wee, Young-Jung; Yun, Jong-Sun; Ryu, Hwa-Won

2005-01-01

A new acetic acid-producing microorganism, Acetobacter sp. RKY4, was isolated from Korean traditional persimmon vinegar, and we optimized the culture medium for acetic acid production from ethanol using the newly isolated Acetobacter sp. RKY4. The optimized culture medium for acetic acid production using this microorganism was found to be 40 g/L ethanol, 10 g/L glycerol, 10 g/L corn steep liquor, 0.5 g/L MgSO4.7H2O, and 1.0 g/L (NH4)H2PO4. Acetobacter sp. RKY4 produced 47.1 g/L of acetic acid after 48 h of fermentation in a 250 mL Erlenmeyer flask containing 50 mL of the optimized medium.

Purification Techniques of Bacteriocins from Lactic Acid Bacteria and Other Gram-Positive Bacteria

NASA Astrophysics Data System (ADS)

Saavedra, Lucila; Sesma, Fernando

The search for new antimicrobial peptides produced by lactic acid ­bacteria and other Gram-positive microorganisms has become an interesting field of research in the past decades. The fact that bacteriocins are active against numerous foodborne and human pathogens, are produced by generally regarded as safe (GRAS) microorganisms, and are readily degraded by proteolytic host systems makes them attractive candidates for biotechnological applications. However, before suggesting or choosing a new bacteriocin for future technology developments, it is necessary to elucidate its biochemical structure and its mode of action, which may be carried out once the bacteriocin is purified to homogeneity. This chapter focuses on describing the main strategies used for the purification of numerous bacteriocins.

Natural products discovery from micro-organisms in the post-genome era.

PubMed

Ikeda, Haruo

2017-01-01

With the decision to award the Nobel Prize in Physiology or Medicine to Drs. S. Ōmura, W.C. Campbell, and Y. Tu, the importance and usefulness of natural drug discovery and development have been revalidated. Since the end of the twentieth century, many genome analyses of organisms have been conducted, and accordingly, numerous microbial genomes have been decoded. In particular, genomic studies of actinomycetes, micro-organisms that readily produce natural products, led to the discovery of biosynthetic gene clusters responsible for producing natural products. New explorations for natural products through a comprehensive approach combining genomic information with conventional methods show great promise for the discovery of new natural products and even systematic generation of unnaturally occurring compounds.

Strain improvement of industrially important microorganisms based on resistance to toxic metabolites and abiotic stress.

PubMed

Fiedurek, Jan; Trytek, Mariusz; Szczodrak, Janusz

2017-06-01

Improvement of the biosynthetic capabilities of industrially relevant microbes to produce desired metabolites in higher quantities is one of the important topics of modern biotechnology. In this article, different strategies of improvement of mutated microbial strains are briefly described. This is followed by the first comprehensive review of the literature on obtaining high yielding microorganisms, that is, mutants exhibiting resistance to antimetabolites, nutritional repression, and abiotic stresses as well as tolerance to solvents and toxic substrates or products. Furthermore, the efficiency of the microbial metabolites produced by improved microbial strains, advantages, and limitations, as well as future prospects for strategies of strain development are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Direct Ethanol Production from Lignocellulosic Sugars and Sugarcane Bagasse by a Recombinant Trichoderma reesei Strain HJ48

PubMed Central

Huang, Jun; Chen, Dong; Wei, Yutuo; Wang, Qingyan; Li, Zhenchong; Chen, Ying; Huang, Ribo

2014-01-01

Trichoderma reesei can be considered as a candidate for consolidated bioprocessing (CBP) microorganism. However, its ethanol yield needs to be improved significantly. Here the ethanol production of T. reesei CICC 40360 was improved by genome shuffling while simultaneously enhancing the ethanol resistance. The initial mutant population was generated by nitrosoguanidine treatment of the spores, and an improved population producing more than fivefold ethanol than wild type was obtained by genome shuffling. The results show that the shuffled strain HJ48 can efficiently convert lignocellulosic sugars to ethanol under aerobic conditions. Furthermore, it was able to produce ethanol directly from sugarcane bagasse, demonstrating that the shuffled strain HJ48 is a suitable microorganism for consolidated bioprocessing. PMID:24995362

Direct ethanol production from lignocellulosic sugars and sugarcane bagasse by a recombinant Trichoderma reesei strain HJ48.

PubMed

Huang, Jun; Chen, Dong; Wei, Yutuo; Wang, Qingyan; Li, Zhenchong; Chen, Ying; Huang, Ribo

2014-01-01

Trichoderma reesei can be considered as a candidate for consolidated bioprocessing (CBP) microorganism. However, its ethanol yield needs to be improved significantly. Here the ethanol production of T. reesei CICC 40360 was improved by genome shuffling while simultaneously enhancing the ethanol resistance. The initial mutant population was generated by nitrosoguanidine treatment of the spores, and an improved population producing more than fivefold ethanol than wild type was obtained by genome shuffling. The results show that the shuffled strain HJ48 can efficiently convert lignocellulosic sugars to ethanol under aerobic conditions. Furthermore, it was able to produce ethanol directly from sugarcane bagasse, demonstrating that the shuffled strain HJ48 is a suitable microorganism for consolidated bioprocessing.

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.

Necromass as a source of energy to microorganisms in marine sediments.

NASA Astrophysics Data System (ADS)

Bradley, J.; Amend, J.; LaRowe, D.

2017-12-01

Marine sediments constitute one of the largest, most energy-limited biospheres on Earth. Despite increasing exploration and interest characterizing microbial communities in marine sediments, the production and role of microbial dead-matter (necromass) has largely been overlooked. Necromass is produced on a global scale, yet its significance as a power source to heterotrophic microorganisms remains unknown. We developed a physical, bio-energetic and geochemical model to quantify the total power supply from necromass oxidation and the total power demand of living microorganisms in marine sediments. This model is first applied to sediments from the oligotrophic South Pacific Gyre (SPG), where organic carbon and biomass concentrations are extremely low, yet microorganisms persist for millions of years in some of the lowest energy states on Earth. We show that necromass does not supply sufficient power to support the total demands of the living community (<39%) at SPG. Application of our model on a global scale, however, shows that necromass produced and subsequently oxidized can provide sufficient power to satisfy the maintenance demands of microorganisms in marine sediments for up to 60,000 years following burial. Our model assumes that all counted cells are viable. Yet, if only a fraction of counted cells are alive, the role of necromass as an electron donor in fueling microbial metabolisms is even greater. This new insight requires a reassessment of carbon fluxes in the deep biosphere. By extension, we also demonstrate a mechanism for microbial communities to persist by oxidizing necromass over geological timescales, and thereby endure unfavorable, low-energy settings that might be analogous to conditions on early Earth and on other planetary bodies.

A diagnosis of the microbiological quality of dehydrated bee-pollen produced in Brazil.

PubMed

De-Melo, A A M; Estevinho, M L M F; Almeida-Muradian, L B

2015-11-01

Bee-pollen is an apicultural product with potential for medical and nutritional applications; therefore, its microbiology quality should be monitored. In this context, the objective of this study was to diagnose the microbiological quality of 45 dehydrated bee-pollen samples collected from November 2011 to December 2013 in nine Brazilian States. All the samples were negative for sulphite-reducing Clostridium spores, Salmonella, coagulase-positive Staphylococcus and Escherichia coli, which are micro-organisms of public health concern. Total aerobic mesophilic micro-organism counts ranged from <10 to 1·10 × 10(4) CFU g(-1) , with psychrotroph counts ranging from <10 to 1·12 × 10(3) CFU g(-1) and total coliforms from <10 to 2·80 × 10(3) CFU g(-1) , while the values for yeasts and moulds were between <10 to 7·67 × 10(3) CFU g(-1) . According to the literature, the microbiota observed in this study were typical; however, it is important to consider that these micro-organisms may cause spoilage and diminish shelf life, reason by which quality control programs should be implemented. Contamination of bee-pollen can occur during production, collection and processing, but there are few studies of the microbiological quality of this product. Brazil is an important producer of dehydrated bee-pollen, therefore, a diagnosis of the microbiological status is important to ensure the safety of many consumers. Salmonella sp., genus Clostridium, coagulase-positive Staphylococcus, Escherichia coli and even some yeast species are micro-organisms of public health concern and their presence must be monitored. Furthermore, the determination of spoilage micro-organisms indicates whether the production and the processing practices carried out by beekeepers and warehouses were adequate. © 2015 The Society for Applied Microbiology.

Generation of PHB from Spent Sulfite Liquor Using Halophilic Microorganisms

PubMed Central

Weissgram, Michaela; Gstöttner, Janina; Lorantfy, Bettina; Tenhaken, Raimund; Herwig, Christoph; Weber, Hedda K.

2015-01-01

Halophilic microorganisms thrive at elevated concentrations of sodium chloride up to saturation and are capable of growing on a wide variety of carbon sources like various organic acids, hexose and also pentose sugars. Hence, the biotechnological application of these microorganisms can cover many aspects, such as the treatment of hypersaline waste streams of different origin. Due to the fact that the high osmotic pressure of hypersaline environments reduces the risk of contamination, the capacity for cost-effective non-sterile cultivation can make extreme halophilic microorganisms potentially valuable organisms for biotechnological applications. In this contribution, the stepwise use of screening approaches, employing design of experiment (DoE) on model media and subsequently using industrial waste as substrate have been implemented to investigate the applicability of halophiles to generate PHB from the industrial waste stream spent sulfite liquor (SSL). The production of PHB on model media as well as dilutions of industrial substrate in a complex medium has been screened for by fluorescence microscopy using Nile Blue staining. Screening was used to investigate the ability of halophilic microorganisms to withstand the inhibiting substances of the waste stream without negatively affecting PHB production. It could be shown that neither single inhibiting substances nor a mixture thereof inhibited growth in the investigated range, hence, leaving the question on the inhibiting mechanisms open. However, it could be demonstrated that some haloarchaea and halophilic bacteria are able to produce PHB when cultivated on 3.3% w/w dry matter spent sulfite liquor, whereas H. halophila was even able to thrive on 6.6% w/w dry matter spent sulfite liquor and still produce PHB. PMID:27682089

[Promoting efficiency of microbial extracellular electron transfer by synthetic biology].

PubMed

Li, Feng; Song, Hao

2017-03-25

Electroactive bacteria, including electrigenic bacteria (exoelectrogens) and electroautotrophic bacteria, implement microbial bioelectrocatalysis processes via bi-directional exchange of electrons and energy with environments, enabling a wide array of applications in environmental and energy fields, including microbial fuel cells (MFC), microbial electrolysis cells (MEC), microbial electrosynthesis (MES) to produce electricity and bulk fine chemicals. However, the low efficiency in the extracellular electron transfer (EET) of exoelectrogens and electrotrophic microbes limited their industrial applications. Here, we reviewed synthetic biology approaches to engineer electroactive microorganisms to break the bottleneck of their EET pathways, to achieve higher efficiency of EET of a number of electroactive microorganisms. Such efforts will lead to a breakthrough in the applications of these electroactive microorganisms and microbial electrocatalysis systems.

Biological Synthesis of Nanoparticles from Plants and Microorganisms.

PubMed

Singh, Priyanka; Kim, Yu-Jin; Zhang, Dabing; Yang, Deok-Chun

2016-07-01

Nanotechnology has become one of the most promising technologies applied in all areas of science. Metal nanoparticles produced by nanotechnology have received global attention due to their extensive applications in the biomedical and physiochemical fields. Recently, synthesizing metal nanoparticles using microorganisms and plants has been extensively studied and has been recognized as a green and efficient way for further exploiting microorganisms as convenient nanofactories. Here, we explore and detail the potential uses of various biological sources for nanoparticle synthesis and the application of those nanoparticles. Furthermore, we highlight recent milestones achieved for the biogenic synthesis of nanoparticles by controlling critical parameters, including the choice of biological source, incubation period, pH, and temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Types of microbial contaminants in pharmaceutical raw materials].

PubMed

Martínez-Bermúdez, A; Rodríguez-de Lecea, J; Soto-Esteras, T; Vázquez-Estévez, C; Chena-Cañete, C

1991-01-01

In order to analyze the significance of the microbial content of pharmaceutical raw materials contributed to the finished pharmaceutical products, we have carried out a study of contamination taking into account aerobic bacteria, anaerobic bacteria and fungi. None or only low numbers of pathogenic microorganisms was found in most analyzed products but in some materials, specially those of natural origin, we have detected high bacterial and fungal contamination. Microorganisms of the genus Bacillus have been the aerobic bacteria most frequently isolated; Bifidobacterium and Clostridium were the most common anaerobic bacteria and with respect to the fungi, Penicillium and Aspergillus have been found with the highest frequency. These microorganisms can produce problems in pharmaceutical finished products, due to their enzymatic or toxigenic activities.

Synthesis, Production, and Biotechnological Applications of Exopolysaccharides and Polyhydroxyalkanoates by Archaea

PubMed Central

Poli, Annarita; Di Donato, Paola; Abbamondi, Gennaro Roberto; Nicolaus, Barbara

2011-01-01

Extreme environments, generally characterized by atypical temperatures, pH, pressure, salinity, toxicity, and radiation levels, are inhabited by various microorganisms specifically adapted to these particular conditions, called extremophiles. Among these, the microorganisms belonging to the Archaea domain are of significant biotechnological importance as their biopolymers possess unique properties that offer insights into their biology and evolution. Particular attention has been devoted to two main types of biopolymers produced by such peculiar microorganisms, that is, the extracellular polysaccharides (EPSs), considered as a protection against desiccation and predation, and the endocellular polyhydroxyalkanoates (PHAs) that provide an internal reserve of carbon and energy. Here, we report the composition, biosynthesis, and production of EPSs and PHAs by different archaeal species. PMID:22007151

Chemosensory cues alter earthworm (Eisenia fetida) avoidance of lead-contaminated soil.

PubMed

Syed, Zuby; Alexander, Dana; Ali, Jasmine; Unrine, Jason; Shoults-Wilson, W Aaron

2017-04-01

Earthworms were shown to significantly avoid soils spiked with Pb at concentrations lower than or comparable to concentrations that demonstrate significant effects for other endpoints. It was also shown that inclusion of a microorganism-produced volatile compound that attracts earthworms, ethyl valerate, decreased avoidance of spiked soils. These findings suggest that care should be taken when analyzing earthworm avoidance of soils in which microorganism communities are not controlled. Environ Toxicol Chem 2017;36:999-1004. © 2016 SETAC. © 2016 SETAC.

COMPLETE REDUCTION OF TELLURITE TO PURE TELLURIUM METAL BY MICROORGANISMS

PubMed Central

Tucker, Fayne L.; Walper, John F.; Appleman, Milo Don; Donohue, Jerry

1962-01-01

Tucker, Fayne L. (University of Southern California, Los Angeles), John F. Walper, Milo Don Appleman, and Jerry Donohue. Complete reduction of tellurite to pure tellurium metal by microorganisms. J. Bacteriol. 83:1313–1314. 1962—The black precipitate produced in the presence of potassium tellurite by growing cells of Streptococcus faecalis N83 and Corynebacterium diphtheriae was shown, by X-ray diffraction analysis, to consist of metallic tellurium. The metal was not complexed, to any significant degree, with any organic material. PMID:13922991

The production of coenzyme Q10 in microorganisms.

PubMed

Cluis, Corinne P; Pinel, Dominic; Martin, Vincent J

2012-01-01

Coenzyme Q10 has emerged as a valuable molecule for pharmaceutical and cosmetic applications. Therefore, research into producing and optimizing coenzyme Q10 via microbial fermentation is ongoing. There are two major paths being explored for maximizing production of this molecule to commercially advantageous levels. The first entails using microbes that naturally produce coenzyme Q10 as fermentation biocatalysts and optimizing the fermentation parameters in order to reach industrial levels of production. However, the natural coenzyme Q10-producing microbes tend to be intractable for industrial fermentation settings. The second path to coenzyme Q10 production being explored is to engineer Escherichia coli with the ability to biosynthesize this molecule in order to take advantage of its more favourable fermentation characteristics and the well-understood array of genetic tools available for this bacteria. Although many studies have attempted to over-produce coenzyme Q10 in E. coli through genetic engineering, production titres still remain below those of the natural coenzyme Q10-producing microorganisms. Current research is providing the knowledge needed to alleviate the bottlenecks involved in producing coenzyme Q10 from an E. coli strain platform and the fermentation parameters that could dramatically increase production titres from natural microbial producers. Synthesizing the lessons learned from both approaches may be the key towards a more cost-effective coenzyme Q10 industry.

Sulfide Generation by Dominant Halanaerobium Microorganisms in Hydraulically Fractured Shales

PubMed Central

Booker, Anne E.; Borton, Mikayla A.; Daly, Rebecca A.; Welch, Susan A.; Nicora, Carrie D.; Hoyt, David W.; Wilson, Travis; Purvine, Samuel O.; Wolfe, Richard A.; Sharma, Shikha; Mouser, Paula J.; Cole, David R.; Lipton, Mary S.; Wrighton, Kelly C.

2017-01-01

ABSTRACT Hydraulic fracturing of black shale formations has greatly increased United States oil and natural gas recovery. However, the accumulation of biomass in subsurface reservoirs and pipelines is detrimental because of possible well souring, microbially induced corrosion, and pore clogging. Temporal sampling of produced fluids from a well in the Utica Shale revealed the dominance of Halanaerobium strains within the in situ microbial community and the potential for these microorganisms to catalyze thiosulfate-dependent sulfidogenesis. From these field data, we investigated biogenic sulfide production catalyzed by a Halanaerobium strain isolated from the produced fluids using proteogenomics and laboratory growth experiments. Analysis of Halanaerobium isolate genomes and reconstructed genomes from metagenomic data sets revealed the conserved presence of rhodanese-like proteins and anaerobic sulfite reductase complexes capable of converting thiosulfate to sulfide. Shotgun proteomics measurements using a Halanaerobium isolate verified that these proteins were more abundant when thiosulfate was present in the growth medium, and culture-based assays identified thiosulfate-dependent sulfide production by the same isolate. Increased production of sulfide and organic acids during the stationary growth phase suggests that fermentative Halanaerobium uses thiosulfate to remove excess reductant. These findings emphasize the potential detrimental effects that could arise from thiosulfate-reducing microorganisms in hydraulically fractured shales, which are undetected by current industry-wide corrosion diagnostics. IMPORTANCE Although thousands of wells in deep shale formations across the United States have been hydraulically fractured for oil and gas recovery, the impact of microbial metabolism within these environments is poorly understood. Our research demonstrates that dominant microbial populations in these subsurface ecosystems contain the conserved capacity for the reduction of thiosulfate to sulfide and that this process is likely occurring in the environment. Sulfide generation (also known as “souring”) is considered deleterious in the oil and gas industry because of both toxicity issues and impacts on corrosion of the subsurface infrastructure. Critically, the capacity for sulfide generation via reduction of sulfate was not detected in our data sets. Given that current industry wellhead tests for sulfidogenesis target canonical sulfate-reducing microorganisms, these data suggest that new approaches to the detection of sulfide-producing microorganisms may be necessary. PMID:28685163

Sulfide Generation by Dominant Halanaerobium Microorganisms in Hydraulically Fractured Shales

DOE Office of Scientific and Technical Information (OSTI.GOV)

Booker, Anne E.; Borton, Mikayla A.; Daly, Rebecca A.

ABSTRACT Hydraulic fracturing of black shale formations has greatly increased United States oil and natural gas recovery. However, the accumulation of biomass in subsurface reservoirs and pipelines is detrimental because of possible well souring, microbially induced corrosion, and pore clogging. Temporal sampling of produced fluids from a well in the Utica Shale revealed the dominance ofHalanaerobiumstrains within thein situmicrobial community and the potential for these microorganisms to catalyze thiosulfate-dependent sulfidogenesis. From these field data, we investigated biogenic sulfide production catalyzed by aHalanaerobiumstrain isolated from the produced fluids using proteogenomics and laboratory growth experiments. Analysis ofHalanaerobiumisolate genomes and reconstructed genomes frommore » metagenomic data sets revealed the conserved presence of rhodanese-like proteins and anaerobic sulfite reductase complexes capable of converting thiosulfate to sulfide. Shotgun proteomics measurements using aHalanaerobiumisolate verified that these proteins were more abundant when thiosulfate was present in the growth medium, and culture-based assays identified thiosulfate-dependent sulfide production by the same isolate. Increased production of sulfide and organic acids during the stationary growth phase suggests that fermentativeHalanaerobiumuses thiosulfate to remove excess reductant. These findings emphasize the potential detrimental effects that could arise from thiosulfate-reducing microorganisms in hydraulically fractured shales, which are undetected by current industry-wide corrosion diagnostics. IMPORTANCEAlthough thousands of wells in deep shale formations across the United States have been hydraulically fractured for oil and gas recovery, the impact of microbial metabolism within these environments is poorly understood. Our research demonstrates that dominant microbial populations in these subsurface ecosystems contain the conserved capacity for the reduction of thiosulfate to sulfide and that this process is likely occurring in the environment. Sulfide generation (also known as “souring”) is considered deleterious in the oil and gas industry because of both toxicity issues and impacts on corrosion of the subsurface infrastructure. Critically, the capacity for sulfide generation via reduction of sulfate was not detected in our data sets. Given that current industry wellhead tests for sulfidogenesis target canonical sulfate-reducing microorganisms, these data suggest that new approaches to the detection of sulfide-producing microorganisms may be necessary.« less

Biogas production from pineapple core - A preliminary study

NASA Astrophysics Data System (ADS)

Jehan, O. S.; Sanusi, S. N. A.; Sukor, M. Z.; Noraini, M.; Buddin, M. M. H. S.; Hamid, K. H. K.

2017-09-01

Anaerobic digestion of pineapple waste was investigated by using pineapple core as the sole substrate. Pineapple core was chosen due to its high total sugar content thus, indicating high amount of fermentable sugar. As digestion process requires the involvement of microorganisms, wastewater from the same industry was added in the current study at ratio of 1:1 by weight. Two different sources of wastewater (Point 1 and Point 2) were used in this study to distinguish the performance of microorganism consortia in both samples. The experiment was conducted by using a lab scale batch anaerobic digester made up from 5L container with separate gas collecting system. The biogas produced was collected by using water displacement method. The experiment was conducted for 30 days and the biogas produced was collected and its volume was recorded at 3 days interval. Based on the data available, wastewater from the first point recorded higher volume of biogas with the total accumulated biogas volume is 216.1 mL. Meanwhile, wastewater sample from Point 2 produced a total of 140.5 mL of biogas, by volume. The data shows that the origin and type of microorganism undeniably play significant role in biogas production. In fact, other factors; pH of wastewater and temperature were also known to affect biogas production. The anaerobic digestion is seen as the promising and sustainable alternatives to current disposal method.

In vivo induction of neutrophil extracellular traps by Mycobacterium tuberculosis in a guinea pig model.

PubMed

Filio-Rodríguez, Georgina; Estrada-García, Iris; Arce-Paredes, Patricia; Moreno-Altamirano, María M; Islas-Trujillo, Sergio; Ponce-Regalado, M Dolores; Rojas-Espinosa, Oscar

2017-10-01

In 2004, a novel mechanism of cellular death, called 'NETosis', was described in neutrophils. This mechanism, different from necrosis and apoptosis, is characterized by the release of chromatin webs admixed with microbicidal granular proteins and peptides (NETs). NETs trap and kill a variety of microorganisms. Diverse microorganisms, including Mycobacterium tuberculosis, are NET inducers in vitro. The aim of this study was to examine whether M. tuberculosis can also induce NETs in vivo and if the NETs are bactericidal to the microorganism. Guinea pigs were intradermally inoculated with M. tuberculosis H37Rv, and the production of NETs was investigated at several time points thereafter. NETs were detected as early as 30 min post-inoculation and were clearly evident by 4 h post-inoculation. NETs produced in vivo contained DNA, myeloperoxidase, elastase, histones, ROS and acid-fast bacilli. Viable and heat-killed M. tuberculosis, as well as Mycobacterium bovis BCG were efficient NET inducers, as were unilamellar liposomes prepared with lipids from M. tuberculosis. In vitro, guinea pig neutrophils also produced NETs in response to M. tuberculosis. However, neither the in vivo nor the in vitro-produced NETs were able to kill M. tuberculosis. Nevertheless, in vivo, neutrophils might propitiate recruitment and activation of more efficient microbicidal cells.

Brachybacterium sp. CH-KOV3 isolated from an oil-polluted environment-a new producer of levan.

PubMed

Djurić, Aleksandra; Gojgić-Cvijović, Gordana; Jakovljević, Dragica; Kekez, Branka; Kojić, Jovana Stefanović; Mattinen, Maija-Liisa; Harju, Inka Elina; Vrvić, Miroslav M; Beškoski, Vladimir P

2017-11-01

Various microorganisms isolated from polluted environments, such as Pseudomonas sp. and Micrococcus sp. can synthesize exopolysaccharides (EPSs) which are natural, non-toxic and biodegradable polymers. EPSs play a key role in protection of microbial cells under various external influences. For humans, these substances have potential use in many industries. EPSs can be applied as a flavor or a fragrance carrier, an emulsifier, a stabilizer, a prebiotic, an antioxidant or an antitumor agent. In this study, we characterized an environmental microorganism that produces EPS, optimized EPS production by this strain and characterized the EPS produced. Isolate CH-KOV3 was identified as Brachybacterium paraconglomeratum. The sucrose level in the growth medium greatly influenced EPS production, and the highest yield was when the microorganism was incubated in media with 500g/L of sucrose. The optimal temperature and pH were 28°C and 7.0, respectively. The nuclear magnetic resonance (NMR) results and GC-MS analysis confirmed that the residues were d-fructofuranosyl residues with β-configuration, where fructose units are linked by β-2,6-glycosidic bonds, with β-2,1-linked branches. All these data indicate that the investigated EPS is a levan-type polysaccharide. Thus, it was concluded that Brachybacterium sp. CH-KOV3 could constitute a new source for production of the bioactive polysaccharide, levan. Copyright © 2017 Elsevier B.V. All rights reserved.

Toxin producing micromycetes on fruit, berries, and vegetables.

PubMed

Lugauskas, Albinas; Stakeniene, Jurgita

2002-01-01

In 1999-2001 the investigations on mycological state of stored and sold fruit, berries, and vegetables grown in Lithuania and imported from other countries were performed. The samples of foodstuff were taken from storehouses, various supermarkets, and market places. Such ecological conditions lead to a rapid spreading of micromycetes and contamination of other articles of food stored and sold nearby. On fresh fruit and berries the development of microorganisms is slow. However, microorganisms penetrate into internal tissues of berries and fruit, thus becoming difficult to notice visually. Some microorganisms, especially micromycetes of some species belonging to the Penicillium Link, Aspergillus Mich. ex Fr., and other genera, are able to produce secondary metabolites (mycotoxins) of various compositions that are toxic to plants, animals, and humans. Therefore, the ability of micromycetes to synthesise and excrete toxic secondary metabolites was examined. Considering this issue, 393 micromycete strains ascribed to 54 genera and 176 species were tested. 46 strains were identified as active producers of toxic substances and were selected for further examinations. Most of them belonged to the Penicillium, Aspergillus and Fusarium genera. Their detection frequency on the investigated berries, fruit, and vegetables was determined, and the impact upon warm-blooded animals (BALB/c mice) was tested. Significant changes of the internal organs and blood composition were found in mice infected with toxic micromycetes. In conclusion, it was evidenced that more than 10% of micromycete strains developing on incorrectly-preserved fruit, berries and vegetables, produce toxic secondary metabolites that pose a potential health hazard for people eating or handling the foodstuff.

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.

Evaluation of sessile microorganisms in pipelines and cooling towers of some Iranian industries

NASA Astrophysics Data System (ADS)

Setareh, M.; Javaherdashti, R.

2006-02-01

Microbiologically influenced corrosion (MIC) is a kind of electrochemical corrosion that is enhanced by the effect of certain microorganisms including sessile bacteria. In this investigation, more than 200 samples collected from different systems of Iranian refineries have been examined (by culturing methods and observations) for corrosion-enhancing, biofilm-producing microorganisms such as sulfate-reducing bacteria (SRB), iron-oxidizing bacteria (IOB), heterotrophic biofilm-forming bacteria (HBB), and some eukaryotes such as fungi. This study showed the presence of microorganisms, such as SRB, HBB, thermophillic HBB, and yeasts, except for IOB. It was also revealed that biocides are used to reduce the number of planktonic (floating) bacteria, instead of the number of sessile bacteria, that form biofilms. Using surfactants, or washing with chemicals like chlorine or organic acids in overhauls, may destroy the biofilm and free the residential bacteria into the bulk solution, thus exposing them to the biocide. For thick biofilms, a chlorine or acid wash may also yield the same results.

Biotechnological approaches for the production of polyhydroxyalkanoates in microorganisms and plants - a review.

PubMed

Suriyamongkol, Pornpa; Weselake, Randall; Narine, Suresh; Moloney, Maurice; Shah, Saleh

2007-01-01

The increasing effect of non-degradable plastic wastes is a growing concern. Polyhydroxyalkanoates (PHAs), macromolecule-polyesters naturally produced by many species of microorganisms, are being considered as a replacement for conventional plastics. Unlike petroleum-derived plastics that take several decades to degrade, PHAs can be completely bio-degraded within a year by a variety of microorganisms. This biodegradation results in carbon dioxide and water, which return to the environment. Attempts based on various methods have been undertaken for mass production of PHAs. Promising strategies involve genetic engineering of microorganisms and plants to introduce production pathways. This challenge requires the expression of several genes along with optimization of PHA synthesis in the host. Although excellent progress has been made in recombinant hosts, the barriers to obtaining high quantities of PHA at low cost still remain to be solved. The commercially viable production of PHA in crops, however, appears to be a realistic goal for the future.

Alternaria sp. MG1, a resveratrol-producing fungus: isolation, identification, and optimal cultivation conditions for resveratrol production

USDA-ARS?s Scientific Manuscript database

Due to its potential in preventing or slowing the occurrence of many diseases, resveratrol (3,5,4-trihydroxystilbene) has attracted great research interest. The objective of this study was to identify the microorganisms that possess resveratrol producing capability from selected plants and optimize ...

Lymph nodes

MedlinePlus Videos and Cool Tools

... and conveying lymph and by producing various blood cells. Lymph nodes play an important part in the ... the microorganisms being trapped inside collections of lymph cells or nodes. Eventually, these organisms are destroyed and ...

H2 and acetate transfers during xylan fermentation between a butyrate-producing xylanolytic species and hydrogenotrophic microorganisms from the human gut.

PubMed

Chassard, Christophe; Bernalier-Donadille, Annick

2006-01-01

The aim of this work was to investigate in vitro interrelationships during xylan fermentation between an H2 and butyrate-producing xylanolytic species recently isolated in our laboratory from human faeces and identified as Roseburia intestinalis and the H2-utilizing acetogen Ruminococcus hydrogenotrophicus or the methanogen Methanobrevibacter smithii. H2 transfer between M. smithii or Ru. hydrogenotrophicus and the xylanolytic species was evidenced, confirming the great potential of these H2-consuming microorganisms to reutilize fermentative H2 during fibre fermentation in the gut. In addition, acetate transfer was demonstrated between the xylanolytic Roseburia sp. and the acetogenic species, both metabolites transfers leading to butyric fermentation of oat xylan without production of H2.

Isolation of antimicrobial producing Actinobacteria from soil samples.

PubMed

Elbendary, Afaf Ahmed; Hessain, Ashgan Mohamed; El-Hariri, Mahmoud Darderi; Seida, Ahmed Adel; Moussa, Ihab Mohamed; Mubarak, Ayman Salem; Kabli, Saleh A; Hemeg, Hassan A; El Jakee, Jakeen Kamal

2018-01-01

Emergence of multidrug resistant bacteria has made the search for novel bioactive compounds from natural and unexplored habitats a necessity. Actinobacteria have important bioactive substances. The present study investigated antimicrobial activity of Actinobacteria isolated from soil samples of Egypt. One hundred samples were collected from agricultural farming soil of different governorates. Twelve isolates have produced activity against the tested microorganisms ( S. aureus , Bacillus cereus , E. coli , K. pneumoniae , P. aeruginosa , S. Typhi, C. albicans , A. niger and A. flavus ). By VITEK 2 system version: 07.01 the 12 isolates were identified as Kocuria kristinae , Kocuria rosea , Streptomyces griseus , Streptomyces flaveolus and Actinobacteria . Using ethyl acetate extraction method the isolates culture's supernatants were tested by diffusion method against indicator microorganisms. These results indicate that Actinobacteria isolated from Egypt farms could be sources of antimicrobial bioactive substances.

Advancing metabolic engineering through systems biology of industrial microorganisms.

PubMed

Dai, Zongjie; Nielsen, Jens

2015-12-01

Development of sustainable processes to produce bio-based compounds is necessary due to the severe environmental problems caused by the use of fossil resources. Metabolic engineering can facilitate the development of highly efficient cell factories to produce these compounds from renewable resources. The objective of systems biology is to gain a comprehensive and quantitative understanding of living cells and can hereby enhance our ability to characterize and predict cellular behavior. Systems biology of industrial microorganisms is therefore valuable for metabolic engineering. Here we review the application of systems biology tools for the identification of metabolic engineering targets which may lead to reduced development time for efficient cell factories. Finally, we present some perspectives of systems biology for advancing metabolic engineering further. Copyright © 2015 Elsevier Ltd. All rights reserved.

The medically important aerobic actinomycetes: epidemiology and microbiology.

PubMed Central

McNeil, M M; Brown, J M

1994-01-01

The aerobic actinomycetes are soil-inhabiting microorganisms that occur worldwide. In 1888, Nocard first recognized the pathogenic potential of this group of microorganisms. Since then, several aerobic actinomycetes have been a major source of interest for the commercial drug industry and have proved to be extremely useful microorganisms for producing novel antimicrobial agents. They have also been well known as potential veterinary pathogens affecting many different animal species. The medically important aerobic actinomycetes may cause significant morbidity and mortality, in particular in highly susceptible severely immunocompromised patients, including transplant recipients and patients infected with human immunodeficiency virus. However, the diagnosis of these infections may be difficult, and effective antimicrobial therapy may be complicated by antimicrobial resistance. The taxonomy of these microorganisms has been problematic. In recent revisions of their classification, new pathogenic species have been recognized. The development of additional and more reliable diagnostic tests and of a standardized method for antimicrobial susceptibility testing and the application of molecular techniques for the diagnosis and subtyping of these microorganisms are needed to better diagnose and treat infected patients and to identify effective control measures for these unusual pathogens. We review the epidemiology and microbiology of the major medically important aerobic actinomycetes. Images PMID:7923055

Butyric acid production from red algae by a newly isolated Clostridium sp. S1.

PubMed

Lee, Kyung Min; Choi, Okkyoung; Kim, Ki-Yeon; Woo, Han Min; Kim, Yunje; Han, Sung Ok; Sang, Byoung-In; Um, Youngsoon

2015-09-01

To produce butyric acid from red algae such as Gelidium amansii in which galactose is a main carbohydrate, microorganisms utilizing galactose and tolerating inhibitors in hydrolysis including levulinic acid and 5-hydroxymethylfurfural (HMF) are required. A newly isolated bacterium, Clostridium sp. S1 produced butyric acid not only from galactose as the sole carbon source but also from a mixture of galactose and glucose through simultaneous utilization. Notably, Clostridium sp. S1 produced butyric acid and a small amount of acetic acid with the butyrate:acetate ratio of 45.4:1 and it even converted acetate to butyric acid. Clostridium sp. S1 tolerated 0.5-2 g levulinic acid/l and recovered from HMF inhibition at 0.6-2.5 g/l, resulting in 85-92% butyric acid concentration of the control culture. When acid-pretreated G. amansii hydrolysate was used, Clostridium sp. S1 produced 4.83 g butyric acid/l from 10 g galactose/l and 1 g glucose/l. Clostridium sp. S1 produces butyric acid from red algae due to its characteristics in sugar utilization and tolerance to inhibitors, demonstrating its advantage as a red algae-utilizing microorganism.

Microbial endocrinology and the microbiota-gut-brain axis.

PubMed

Lyte, Mark

2014-01-01

Microbial endocrinology is defined as the study of the ability of microorganisms to both produce and recognize neurochemicals that originate either within the microorganisms themselves or within the host they inhabit. As such, microbial endocrinology represents the intersection of the fields of microbiology and neurobiology. The acquisition of neurochemical-based cell-to-cell signaling mechanisms in eukaryotic organisms is believed to have been acquired due to late horizontal gene transfer from prokaryotic microorganisms. When considered in the context of the microbiota's ability to influence host behavior, microbial endocrinology with its theoretical basis rooted in shared neuroendocrine signaling mechanisms provides for testable experiments with which to understand the role of the microbiota in host behavior and as importantly the ability of the host to influence the microbiota through neuroendocrine-based mechanisms.

Mini-review: Inhibition of biofouling by marine microorganisms.

PubMed

Dobretsov, Sergey; Abed, Raeid M M; Teplitski, Max

2013-01-01

Any natural or artificial substratum exposed to seawater is quickly fouled by marine microorganisms and later by macrofouling species. Microfouling organisms on the surface of a substratum form heterogenic biofilms, which are composed of multiple species of heterotrophic bacteria, cyanobacteria, diatoms, protozoa and fungi. Biofilms on artificial structures create serious problems for industries worldwide, with effects including an increase in drag force and metal corrosion as well as a reduction in heat transfer efficiency. Additionally, microorganisms produce chemical compounds that may induce or inhibit settlement and growth of other fouling organisms. Since the last review by the first author on inhibition of biofouling by marine microbes in 2006, significant progress has been made in the field. Several antimicrobial, antialgal and antilarval compounds have been isolated from heterotrophic marine bacteria, cyanobacteria and fungi. Some of these compounds have multiple bioactivities. Microorganisms are able to disrupt biofilms by inhibition of bacterial signalling and production of enzymes that degrade bacterial signals and polymers. Epibiotic microorganisms associated with marine algae and invertebrates have a high antifouling (AF) potential, which can be used to solve biofouling problems in industry. However, more information about the production of AF compounds by marine microorganisms in situ and their mechanisms of action needs to be obtained. This review focuses on the AF activity of marine heterotrophic bacteria, cyanobacteria and fungi and covers publications from 2006 up to the end of 2012.

Effects of Sterilizing Agents on Microorganisms

DTIC Science & Technology

1963-03-01

light increases with the incubation of Escherichia coli at 15, but the rate of in- 85. ESTUDIO DE LOS EFECTOS QUE PRODUCE duction of mutations...between the deoxyribonucleic acid content of a cell and its response to irradiation: 5-fluor- 86. ESTUDIO DE LOS EFECTOS QUE PRODUCE ouracil treated...EFFECTS OF ULTRAVIOLET LIGHT ON 84. ESTUDIO DE LOS EFECTOS QUE PRODUCE BACTERIA. III. ALTERATIONS IN THE LA LUZ ULTRAVIOLETA SOBRE LAS PHYSIOLOGICAL

Biosurfactant Produced by Salmonella Enteritidis SE86 Can Increase Adherence and Resistance to Sanitizers on Lettuce Leaves (Lactuca sativa L., cichoraceae)

PubMed Central

Rossi, Eliandra M.; Beilke, Luniele; Kochhann, Marília; Sarzi, Diana H.; Tondo, Eduardo C.

2016-01-01

Salmonella Enteritidis SE86 is an important foodborne pathogen in Southern Brazil and it is able to produce a biosurfactant. However, the importance of this compound for the microorganism is still unknown. This study aimed to investigate the influence of the biosurfactant produced by S. Enteritidis SE86 on adherence to slices of lettuce leaves and on resistance to sanitizers. First, lettuce leaves were inoculated with S. Enteritidis SE86 in order to determine the amount of biosurfactant produced. Subsequently, lettuce leaves were inoculated with S. Enteritidis SE86 with and without the biosurfactant, and the adherence and bacterial resistance to different sanitization methods were evaluated. S. Enteritidis SE86 produced biosurfactant after 16 h (emulsification index of 11 to 52.15 percent, P < 0.05) and showed greater adherence capability and resistance to sanitization methods when the compound was present. The scanning electron microscopy demonstrated that S. Enteritidis was able to adhere, form lumps, and invade the lettuce leaves’ stomata in the presence of the biosurfactant. Results indicated that the biosurfactant produced by S. Enteritidis SE86 contributed to adherence and increased resistance to sanitizers when the microorganism was present on lettuce leaves. PMID:26834727

Protection of Nitrate-Reducing Fe(II)-Oxidizing Bacteria from UV Radiation by Biogenic Fe(III) Minerals

NASA Astrophysics Data System (ADS)

Gauger, Tina; Konhauser, Kurt; Kappler, Andreas

2016-04-01

Due to the lack of an ozone layer in the Archean, ultraviolet radiation (UVR) reached early Earth's surface almost unattenuated; as a consequence, a terrestrial biosphere in the form of biological soil crusts would have been highly susceptible to lethal doses of irradiation. However, a self-produced external screen in the form of nanoparticular Fe(III) minerals could have effectively protected those early microorganisms. In this study, we use viability studies by quantifying colony-forming units (CFUs), as well as Fe(II) oxidation and nitrate reduction rates, to show that encrustation in biogenic and abiogenic Fe(III) minerals can protect a common soil bacteria such as the nitrate-reducing Fe(II)-oxidizing microorganisms Acidovorax sp. strain BoFeN1 and strain 2AN from harmful UVC radiation. Analysis of DNA damage by quantifying cyclobutane pyrimidine dimers (CPD) confirmed the protecting effect by Fe(III) minerals. This study suggests that Fe(II)-oxidizing microorganisms, as would have grown in association with mafic and ultramafic soils/outcrops, would have been able to produce their own UV screen, enabling them to live in terrestrial habitats on early Earth.

Protection of Nitrate-Reducing Fe(II)-Oxidizing Bacteria from UV Radiation by Biogenic Fe(III) Minerals.

PubMed

Gauger, Tina; Konhauser, Kurt; Kappler, Andreas

2016-04-01

Due to the lack of an ozone layer in the Archean, ultraviolet radiation (UVR) reached early Earth's surface almost unattenuated; as a consequence, a terrestrial biosphere in the form of biological soil crusts would have been highly susceptible to lethal doses of irradiation. However, a self-produced external screen in the form of nanoparticular Fe(III) minerals could have effectively protected those early microorganisms. In this study, we use viability studies by quantifying colony-forming units (CFUs), as well as Fe(II) oxidation and nitrate reduction rates, to show that encrustation in biogenic and abiogenic Fe(III) minerals can protect a common soil bacteria such as the nitrate-reducing Fe(II)-oxidizing microorganisms Acidovorax sp. strain BoFeN1 and strain 2AN from harmful UVC radiation. Analysis of DNA damage by quantifying cyclobutane pyrimidine dimers (CPD) confirmed the protecting effect by Fe(III) minerals. This study suggests that Fe(II)-oxidizing microorganisms, as would have grown in association with mafic and ultramafic soils/outcrops, would have been able to produce their own UV screen, enabling them to live in terrestrial habitats on early Earth.

Biofuel and chemical production by recombinant microorganisms via fermentation of proteinaceous biomass

DOEpatents

Liao, James C.; Cho, Kwang Myung; Yan, Yajun; Huo, Yixin

2016-03-15

Provided herein are metabolically modified microorganisms characterized by having an increased keto-acid flux when compared with the wild-type organism and comprising at least one polynucleotide encoding an enzyme that when expressed results in the production of a greater quantity of a chemical product when compared with the wild-type organism. The recombinant microorganisms are useful for producing a large number of chemical compositions from various nitrogen containing biomass compositions and other carbon sources. More specifically, provided herein are methods of producing alcohols, acetaldehyde, acetate, isobutyraldehyde, isobutyric acid, n-butyraldehyde, n-butyric acid, 2-methyl-1-butyraldehyde, 2-methyl-1-butyric acid, 3-methyl-1-butyraldehyde, 3-methyl-1-butyric acid, ammonia, ammonium, amino acids, 2,3-butanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 2-methyl-1,4-butanediamine, isobutene, itaconate, acetoin, acetone, isobutene, 1,5-diaminopentane, L-lactic acid, D-lactic acid, shikimic acid, mevalonate, polyhydroxybutyrate (PHB), isoprenoids, fatty acids, homoalanine, 4-aminobutyric acid (GABA), succinic acid, malic acid, citric acid, adipic acid, p-hydroxy-cinnamic acid, tetrahydrofuran, 3-methyl-tetrahydrofuran, gamma-butyrolactone, pyrrolidinone, n-methylpyrrolidone, aspartic acid, lysine, cadeverine, 2-ketoadipic acid, and/or S-adenosyl-methionine (SAM) from a suitable nitrogen rich biomass.

Marine Microbial-Derived Molecules and Their Potential Use in Cosmeceutical and Cosmetic Products

PubMed Central

Corinaldesi, Cinzia; Barone, Giulio; Marcellini, Francesca; Dell’Anno, Antonio; Danovaro, Roberto

2017-01-01

The oceans encompass a wide range of habitats and environmental conditions, which host a huge microbial biodiversity. The unique characteristics of several marine systems have driven a variety of biological adaptations, leading to the production of a large spectrum of bioactive molecules. Fungi, fungi-like protists (such as thraustochytrids) and bacteria are among the marine organisms with the highest potential of producing bioactive compounds, which can be exploited for several commercial purposes, including cosmetic and cosmeceutical ones. Mycosporines and mycosporine-like amino acids, carotenoids, exopolysaccharides, fatty acids, chitosan and other compounds from these microorganisms might represent a sustainable, low-cost and fast-production alternative to other natural molecules used in photo-protective, anti-aging and skin-whitening products for face, body and hair care. Here, we review the existing knowledge of these compounds produced by marine microorganisms, highlighting the marine habitats where such compounds are preferentially produced and their potential application in cosmetic and cosmeceutical fields. PMID:28417932

Nitric Oxide Production by the Human Intestinal Microbiota by Dissimilatory Nitrate Reduction to Ammonium

PubMed Central

Vermeiren, Joan; Van de Wiele, Tom; Verstraete, Willy; Boeckx, Pascal; Boon, Nico

2009-01-01

The free radical nitric oxide (NO) is an important signaling molecule in the gastrointestinal tract. Besides eukaryotic cells, gut microorganisms are also capable of producing NO. However, the exact mechanism of NO production by the gut microorganisms is unknown. Microbial NO production was examined under in vitro conditions simulating the gastrointestinal ecosystem using L-arginine or nitrate as substrates. L-arginine did not influence the microbial NO production. However, NO concentrations in the order of 90 ng NO-N per L feed medium were produced by the fecal microbiota from nitrate. 15N tracer experiments showed that nitrate was mainly reduced to ammonium by the dissimilatory nitrate reduction to ammonium (DNRA) pathway. To our knowledge, this is the first study showing that gastrointestinal microbiota can generate substantial amounts of NO by DNRA and not by the generally accepted denitrification or L-arginine pathway. Further work is needed to elucidate the exact role between NO produced by the gastrointestinal microbiota and host cells. PMID:19888436

MICROBIALLY MEDIATED LEACHING OF RARE EARTH ELEMENTS FROM RECYCLABLE MATERIALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, D. W.; Fujita, Y.; Daubaras, D. L.

2016-09-01

Bioleaching offers a potential approach for recovery of rare earth elements (REE) from recyclable materials, such as fluorescent lamp phosphors or degraded industrial catalysts. Microorganisms were enriched from REE-containing ores and recyclable materials with the goal of identifying strains capable of extracting REE from solid materials. Over 100 heterotrophic microorganisms were isolated and screened for their ability to produce organic acids capable of leaching REE. The ten most promising isolates were most closely related to Pseudomonas, Acinetobacter and Talaromyces. Of the acids produced, gluconic acid appeared to be the most effective at leaching REE (yttrium, lanthanum, cerium, europium, and terbium)more » from retorted phosphor powders (RPP), fluidized cracking catalyst (FCC), and europium-doped yttrium oxide (YOEu). We found that an Acinetobacter isolates, BH1, was the most capable strain and able to leach 33% of the total REE content from the FCC material. These results support the continuing evaluation of gluconic acid-producing microbes for large-scale REE recovery from recyclable materials.« less

Natural chelating agents for radionuclide decorporation

DOEpatents

Premuzic, E.T.

1985-06-11

This invention relates to the production of metal-binding compounds useful for the therapy of heavy metal poisoning, for biological mining and for decorporation of radionuclides. The present invention deals with an orderly and effective method of producing new therapeutically effective chelating agents. This method uses challenge biosynthesis for the production of chelating agents that are specific for a particular metal. In this approach, the desired chelating agents are prepared from microorganisms challenged by the metal that the chelating agent is designed to detoxify. This challenge induces the formation of specific or highly selective chelating agents. The present invention involves the use of the challenge biosynthetic method to produce new complexing/chelating agents that are therapeutically useful to detoxify uranium, plutonium, thorium and other toxic metals. The Pseudomonas aeruginosa family of organisms is the referred family of microorganisms to be used in the present invention to produce the new chelating agent because this family is known to elaborate strains resistant to toxic metals.

Marine Microbial-Derived Molecules and Their Potential Use in Cosmeceutical and Cosmetic Products.

PubMed

Corinaldesi, Cinzia; Barone, Giulio; Marcellini, Francesca; Dell'Anno, Antonio; Danovaro, Roberto

2017-04-12

The oceans encompass a wide range of habitats and environmental conditions, which host a huge microbial biodiversity. The unique characteristics of several marine systems have driven a variety of biological adaptations, leading to the production of a large spectrum of bioactive molecules. Fungi, fungi-like protists (such as thraustochytrids) and bacteria are among the marine organisms with the highest potential of producing bioactive compounds, which can be exploited for several commercial purposes, including cosmetic and cosmeceutical ones. Mycosporines and mycosporine-like amino acids, carotenoids, exopolysaccharides, fatty acids, chitosan and other compounds from these microorganisms might represent a sustainable, low-cost and fast-production alternative to other natural molecules used in photo-protective, anti-aging and skin-whitening products for face, body and hair care. Here, we review the existing knowledge of these compounds produced by marine microorganisms, highlighting the marine habitats where such compounds are preferentially produced and their potential application in cosmetic and cosmeceutical fields.

Butanol production in a first-generation Brazilian sugarcane biorefinery: technical aspects and economics of greenfield projects.

PubMed

Mariano, Adriano Pinto; Dias, Marina O S; Junqueira, Tassia L; Cunha, Marcelo P; Bonomi, Antonio; Filho, Rubens Maciel

2013-05-01

The techno-economics of greenfield projects of a first-generation sugarcane biorefinery aimed to produce ethanol, sugar, power, and n-butanol was conducted taking into account different butanol fermentation technologies (regular microorganism and mutant strain with improved butanol yield) and market scenarios (chemicals and automotive fuel). The complete sugarcane biorefinery with the batch acetone-butanol-ethanol (ABE) fermentation process was simulated using Aspen Plus®. The biorefinery was designed to process 2 million tonne sugarcane per year and utilize 25%, 50%, and 25% of the available sugarcane juice to produce sugar, ethanol, and butanol, respectively. The investment on a biorefinery with butanol production showed to be more attractive [14.8% IRR, P(IRR>12%)=0.99] than the conventional 50:50 (ethanol:sugar) annexed plant [13.3% IRR, P(IRR>12%)=0.80] only in the case butanol is produced by an improved microorganism and traded as a chemical. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nitric oxide production by the human intestinal microbiota by dissimilatory nitrate reduction to ammonium.

PubMed

Vermeiren, Joan; Van de Wiele, Tom; Verstraete, Willy; Boeckx, Pascal; Boon, Nico

2009-01-01

The free radical nitric oxide (NO) is an important signaling molecule in the gastrointestinal tract. Besides eukaryotic cells, gut microorganisms are also capable of producing NO. However, the exact mechanism of NO production by the gut microorganisms is unknown. Microbial NO production was examined under in vitro conditions simulating the gastrointestinal ecosystem using L-arginine or nitrate as substrates. L-arginine did not influence the microbial NO production. However, NO concentrations in the order of 90 ng NO-N per L feed medium were produced by the fecal microbiota from nitrate. (15)N tracer experiments showed that nitrate was mainly reduced to ammonium by the dissimilatory nitrate reduction to ammonium (DNRA) pathway. To our knowledge, this is the first study showing that gastrointestinal microbiota can generate substantial amounts of NO by DNRA and not by the generally accepted denitrification or L-arginine pathway. Further work is needed to elucidate the exact role between NO produced by the gastrointestinal microbiota and host cells.

Roles of microorganisms other than Clostridium and Enterobacter in anaerobic fermentative biohydrogen production systems--a review.

PubMed

Hung, Chun-Hsiung; Chang, Yi-Tang; Chang, Yu-Jie

2011-09-01

Anaerobic fermentative biohydrogen production, the conversion of organic substances especially from organic wastes to hydrogen gas, has become a viable and promising means of producing sustainable energy. Successful biological hydrogen production depends on the overall performance (results of interactions) of bacterial communities, i.e., mixed cultures in reactors. Mixed cultures might provide useful combinations of metabolic pathways for the processing of complex waste material ingredients, thereby supporting the more efficient decomposition and hydrogenation of biomass than pure bacteria species would. Therefore, understanding the relationships between variations in microbial composition and hydrogen production efficiency is the first step in constructing more efficient hydrogen-producing consortia, especially when complex and non-sterilized organic wastes are used as feeding substrates. In this review, we describe recent discoveries on bacterial community composition obtained from dark fermentation biohydrogen production systems, with emphasis on the possible roles of microorganisms that co-exist with common hydrogen producers. Copyright © 2011 Elsevier Ltd. All rights reserved.

A New Tool For The Hospital Lab

NASA Technical Reports Server (NTRS)

1979-01-01

The multi-module AutoMicrobic System (AMS), whose development stemmed from space-biomedical research, is an automatic, time-saving system for detecting and identifying disease-producing microorganisms in the human body.

Production Methods in Industrial Microbiology.

ERIC Educational Resources Information Center

Gaden, Elmer L., Jr.

1981-01-01

Compares two methods (batch and continuous) in which microorganisms are used to produce industrial chemicals. Describes batch and continuous stirred-tank reactors and offers reasons why the batch method may be preferred. (JN)

Indicators: Sediment Enzymes

EPA Pesticide Factsheets

Sediment enzymes are proteins that are produced by microorganisms living in the sediment or soil. They are indicators of key ecosystem processes and can help determine which nutrients are affecting the biological community of a waterbody.

[Water disinfection by the combined exposure to super-high frequency energy and available chlorine produced during water electrolysis].

PubMed

Klimarev, S I; Siniak, Iu E

2014-01-01

The article reports the results of studying the effects on polluted water of SHF-energy together with the residual free (active) chlorine as a by-product of electrolysis action on dissolved chlorine-containing salts. Purpose of the studies was to evaluate input of these elements to the water disinfection effect. The synergy was found to kill microorganisms without impacts on the physicochemical properties of processed water or nutrient medium; therefore, it can be used for water treatment, and cultivation of microorganisms in microbiology.

Omics and multi-omics approaches to study the biosynthesis of secondary metabolites in microorganisms.

PubMed

Palazzotto, Emilia; Weber, Tilmann

2018-04-12

Natural products produced by microorganisms represent the main source of bioactive molecules. The development of high-throughput (omics) techniques have importantly contributed to the renaissance of new antibiotic discovery increasing our understanding of complex mechanisms controlling the expression of biosynthetic gene clusters (BGCs) encoding secondary metabolites. In this context this review highlights recent progress in the use and integration of 'omics' approaches with focuses on genomics, transcriptomics, proteomics metabolomics meta-omics and combined omics as powerful strategy to discover new antibiotics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Process for producing fuel grade ethanol by continuous fermentation, solvent extraction and alcohol separation

DOEpatents

Tedder, Daniel W.

1985-05-14

Alcohol substantially free of water is prepared by continuously fermenting a fermentable biomass feedstock in a fermentation unit, thereby forming an aqueous fermentation liquor containing alcohol and microorganisms. Continuously extracting a portion of alcohol from said fermentation liquor with an organic solvent system containing an extractant for said alcohol, thereby forming an alcohol-organic solvent extract phase and an aqueous raffinate. Said alcohol is separated from said alcohol-organic solvent phase. A raffinate comprising microorganisms and unextracted alcohol is returned to the fermentation unit.

21 CFR 184.1318 - Glucono delta-lactone.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Gluconic acid may be produced by the oxidation of D-glucose with bromine water, by the oxidation of D... oxidation of D-glucose with enzymes derived from these microorganisms. (b) The ingredient meets the...

Evaluation in vitro of the antagonistic substances produced by Lactobacillus spp. isolated from chickens

PubMed Central

Lima, Edna T.; Andreatti Filho, Raphael L.; Okamoto, Adriano S.; Noujaim, José C.; Barros, Mércia R.; Crocci, Adalberto J.

2007-01-01

To determine the inhibitory capacity of lactic acid bacteria due to the action of antagonistic substances, we tested 474 isolates of Lactobacillus from the crop and cecum of chickens against gram-positive and gram-negative indicator microorganisms by the spot-on-the-lawn and well-diffusion antagonism methods. Of the 474 isolates, 265 demonstrated antimicrobial activity against the indicator microorganisms. Isolates identified as L. reuteri, L. salivarius, or Lactobacillus spp. inhibited Enterococcus faecalis, E. faecium, Listeria monocytogenes, and Salmonella spp. but not L. casei, L. delbrueckii, L. fermentum, or L. helveticus by the well-diffusion simultaneous antagonism method under anaerobic incubation conditions. The antagonistic substances produced by some of the Lactobacillus isolates were inactivated after treatment by proteolytic enzymes, which suggested that the substances could be antimicrobial peptides or bacteriocins. PMID:17479773

Simultaneous co-fermentation of mixed sugars: a promising strategy for producing cellulosic ethanol.

PubMed

Kim, Soo Rin; Ha, Suk-Jin; Wei, Na; Oh, Eun Joong; Jin, Yong-Su

2012-05-01

The lack of microbial strains capable of fermenting all sugars prevalent in plant cell wall hydrolyzates to ethanol is a major challenge. Although naturally existing or engineered microorganisms can ferment mixed sugars (glucose, xylose and galactose) in these hydrolyzates sequentially, the preferential utilization of glucose to non-glucose sugars often results in lower overall yield and productivity of ethanol. Therefore, numerous metabolic engineering approaches have been attempted to construct optimal microorganisms capable of co-fermenting mixed sugars simultaneously. Here, we present recent findings and breakthroughs in engineering yeast for improved ethanol production from mixed sugars. In particular, this review discusses new sugar transporters, various strategies for simultaneous co-fermentation of mixed sugars, and potential applications of co-fermentation for producing fuels and chemicals. Copyright © 2012 Elsevier Ltd. All rights reserved.

Megasphaera hexanoica sp. nov., a medium-chain carboxylic acid-producing bacterium isolated from a cow rumen.

PubMed

Jeon, Byoung Seung; Kim, Seil; Sang, Byoung-In

2017-07-01

Strain MHT, a strictly anaerobic, Gram-stain-negative, non-spore-forming, spherical coccus or coccoid-shaped microorganism, was isolated from a cow rumen during a screen for hexanoic acid-producing bacteria. The microorganism grew at 30-40 °C and pH 5.5-7.5 and exhibited production of various short- and medium-chain carboxylic acids (acetic acid, butyric acid, pentanoic acid, isobutyric acid, isovaleric acid, hexanoic acid, heptanoic acid and octanoic acid), as well as H2 and CO2 as biogas. Phylogenetic analysis based on 16S rRNA gene sequencing demonstrated that MHT represents a member of the genus Megasphaera, with the closest relatives being Megapsphaera indica NMBHI-10T (94.1 % 16S rRNA sequence similarity), Megasphaera elsdenii DSM 20460T (93.8 %) and Megasphaera paucivorans DSM 16981T (93.8 %). The major cellular fatty acids produced by MHT included C12 : 0, C16 : 0, C18 : 1cis 9, and C18 : 0, and the DNA G+C content of the MHT genome is 51.8 mol%. Together, the distinctive phenotypic and phylogenetic characteristics of MHT indicate that this microorganism represents a novel species of the genus Megasphaera, for which the name Megasphaera hexanoica sp. nov. is herein proposed. The type strain of this species is MHT (=KCCM 43214T=JCM 31403T).

Microbial Life Driving Low-Temperature Basalt Alteration in the Subsurface: Decoupling Abiotic Processes from Biologically-Mediated Rock Alteration

NASA Astrophysics Data System (ADS)

Moore, R.; Lecoeuvre, A.; Stephant, S.; Dupraz, S.; Ranchou-Peyruse, M.; Ranchou-Peyruse, A.; Gérard, E.; Ménez, B.

2017-12-01

Microorganisms are involved with specific rock alteration processes in the deep subsurface. It is a challenge to link any contribution microbial life may have on rock alteration with specific functions or phyla because many alteration features and secondary minerals produced by metabolic processes can also produce abiotically. Here, two flow-through experiments were designed to mimic the circulation of a CO2-rich fluid through crystalline basalt. In order to identify microbially-mediated alteration and be able to link it with specific metabolisms represented in the subsurface, a relatively fresh crystalline basalt substrate was subsampled, sterilized and used as the substrate for both experiments. In one experiment, the substrate was left sterile, and in the other it was inoculated with an enrichment culture derived from the same aquifer as the rock substrate. Initial results show that the inoculum contained Proteobacteria and Firmicutes, which have diverse metabolic potentials. Fluid and rock analyses before, during, and after the experiments show that mineralogy, fluid chemistry, and dissolution processes differ between the sterile and inoculated systems. In the inoculated experiment iron-rich orthopyroxenes were preferentially dissolved while in the sterile system clinopyroxenes and plagioclases both exhibited a higher degree of dissolution. Additionally, the patterns of CO2 consumption and production over the duration of both experiments is different. This suggest that in a low-temperature basalt system with microorganisms CO2 is either consumed to produce biomass, or that carbonates are produced and then subsequently preserved. This suite of results combined with molecular ecology analyses can be used to conclude that in low-temperature basalts microorganisms play an intrinsic role in rock alteration.

Production of bioplastics and hydrogen gas by photosynthetic microorganisms

NASA Astrophysics Data System (ADS)

Yasuo, Asada; Masato, Miyake; Jun, Miyake

1998-03-01

Our efforts have been aimed at the technological basis of photosynthetic-microbial production of materials and an energy carrier. We report here accumulation of poly-(3-hydroxybutyrate) (PHB), a raw material of biodegradable plastics and for production of hydrogen gas, and a renewable energy carrier by photosynthetic microorganisms (tentatively defined as cyanobacteria plus photosynthetic bateria, in this report). A thermophilic cyanobacterium, Synechococcus sp. MA19 that accumulates PHB at more than 20% of cell dry wt under nitrogen-starved conditions was isolated and microbiologically identified. The mechanism of PHB accumulation was studied. A mesophilic Synechococcus PCC7942 was transformed with the genes encoding PHB-synthesizing enzymes from Alcaligenes eutrophus. The transformant accumulated PHB under nitrogen-starved conditions. The optimal conditions for PHB accumulation by a photosynthetic bacterium grown on acetate were studied. Hydrogen production by photosynthetic microorganisms was studied. Cyanobacteria can produce hydrogen gas by nitrogenase or hydrogenase. Hydrogen production mediated by native hydrogenase in cyanobacteria was revealed to be in the dark anaerobic degradation of intracellular glycogen. A new system for light-dependent hydrogen production was targeted. In vitro and in vivo coupling of cyanobacterial ferredoxin with a heterologous hydrogenase was shown to produce hydrogen under light conditions. A trial for genetic trasformation of Synechococcus PCC7942 with the hydrogenase gene from Clostridium pasteurianum is going on. The strong hydrogen producers among photosynthetic bacteria were isolated and characterized. Co-culture of Rhodobacter and Clostriumdium was applied to produce hydrogen from glucose. Conversely in the case of cyanobacteria, genetic regulation of photosynthetic proteins was intended to improve conversion efficiency in hydrogen production by the photosynthetic bacterium, Rhodobacter sphaeroides RV. A mutant acquired by UV irradiation will be characterized for the mutation and for hydrogen productivity in comparison with the wild type strain. Some basic studies to develop photobioreactors are also introduced.

Ethanol Production by Selected Intestinal Microorganisms and Lactic Acid Bacteria Growing under Different Nutritional Conditions.

PubMed

Elshaghabee, Fouad M F; Bockelmann, Wilhelm; Meske, Diana; de Vrese, Michael; Walte, Hans-Georg; Schrezenmeir, Juergen; Heller, Knut J

2016-01-01

To gain some specific insight into the roles microorganisms might play in non-alcoholic fatty liver disease (NAFLD), some intestinal and lactic acid bacteria and one yeast (Anaerostipes caccae, Bacteroides thetaiotaomicron, Bifidobacterium longum, Enterococcus fecalis, Escherichia coli, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus plantarum, Weissella confusa, Saccharomyces cerevisiae) were characterized by high performance liquid chromatography for production of ethanol when grown on different carbohydrates: hexoses (glucose and fructose), pentoses (arabinose and ribose), disaccharides (lactose and lactulose), and inulin. Highest amounts of ethanol were produced by S. cerevisiae, L. fermentum, and W. confusa on glucose and by S. cerevisiae and W. confusa on fructose. Due to mannitol-dehydrogenase expressed in L. fermentum, ethanol production on fructose was significantly (P < 0.05) reduced. Pyruvate and citrate, two potential electron acceptors for regeneration of NAD(+)/NADP(+), drastically reduced ethanol production with acetate produced instead in L. fermentum grown on glucose and W. confusa grown on glucose and fructose, respectively. In fecal slurries prepared from feces of four overweight volunteers, ethanol was found to be produced upon addition of fructose. Addition of A. caccae, L. acidophilus, L. fermentum, as well as citrate and pyruvate, respectively, abolished ethanol production. However, addition of W. confusa resulted in significantly (P < 0.05) increased production of ethanol. These results indicate that microorganisms like W. confusa, a hetero-fermentative, mannitol-dehydrogenase negative lactic acid bacterium, may promote NAFLD through ethanol produced from sugar fermentation, while other intestinal bacteria and homo- and hetero-fermentative but mannitol-dehydrogenase positive lactic acid bacteria may not promote NAFLD. Also, our studies indicate that dietary factors interfering with gastrointestinal microbiota and microbial metabolism may be important in preventing or promoting NAFLD.

Elucidation of Taste- and Odor-Producing Bacteria and Toxigenic Cyanobacteria in a Midwestern Drinking Water Supply Reservoir by Shotgun Metagenomic Analysis.

PubMed

Otten, Timothy G; Graham, Jennifer L; Harris, Theodore D; Dreher, Theo W

2016-09-01

While commonplace in clinical settings, DNA-based assays for identification or enumeration of drinking water pathogens and other biological contaminants remain widely unadopted by the monitoring community. In this study, shotgun metagenomics was used to identify taste-and-odor producers and toxin-producing cyanobacteria over a 2-year period in a drinking water reservoir. The sequencing data implicated several cyanobacteria, including Anabaena spp., Microcystis spp., and an unresolved member of the order Oscillatoriales as the likely principal producers of geosmin, microcystin, and 2-methylisoborneol (MIB), respectively. To further demonstrate this, quantitative PCR (qPCR) assays targeting geosmin-producing Anabaena and microcystin-producing Microcystis were utilized, and these data were fitted using generalized linear models and compared with routine monitoring data, including microscopic cell counts, sonde-based physicochemical analyses, and assays of all inorganic and organic nitrogen and phosphorus forms and fractions. The qPCR assays explained the greatest variation in observed geosmin (adjusted R(2) = 0.71) and microcystin (adjusted R(2) = 0.84) concentrations over the study period, highlighting their potential for routine monitoring applications. The origin of the monoterpene cyclase required for MIB biosynthesis was putatively linked to a periphytic cyanobacterial mat attached to the concrete drinking water inflow structure. We conclude that shotgun metagenomics can be used to identify microbial agents involved in water quality deterioration and to guide PCR assay selection or design for routine monitoring purposes. Finally, we offer estimates of microbial diversity and metagenomic coverage of our data sets for reference to others wishing to apply shotgun metagenomics to other lacustrine systems. Cyanobacterial toxins and microbial taste-and-odor compounds are a growing concern for drinking water utilities reliant upon surface water resources. Specific identification of the microorganism(s) responsible for water quality degradation is often complicated by the presence of co-occurring taxa capable of producing these undesirable metabolites. Here we present a framework for how shotgun metagenomics can be used to definitively identify problematic microorganisms and how these data can guide the development of rapid genetic assays for routine monitoring purposes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Elucidation of Taste- and Odor-Producing Bacteria and Toxigenic Cyanobacteria in a Midwestern Drinking Water Supply Reservoir by Shotgun Metagenomic Analysis

PubMed Central

Graham, Jennifer L.; Harris, Theodore D.

2016-01-01

ABSTRACT While commonplace in clinical settings, DNA-based assays for identification or enumeration of drinking water pathogens and other biological contaminants remain widely unadopted by the monitoring community. In this study, shotgun metagenomics was used to identify taste-and-odor producers and toxin-producing cyanobacteria over a 2-year period in a drinking water reservoir. The sequencing data implicated several cyanobacteria, including Anabaena spp., Microcystis spp., and an unresolved member of the order Oscillatoriales as the likely principal producers of geosmin, microcystin, and 2-methylisoborneol (MIB), respectively. To further demonstrate this, quantitative PCR (qPCR) assays targeting geosmin-producing Anabaena and microcystin-producing Microcystis were utilized, and these data were fitted using generalized linear models and compared with routine monitoring data, including microscopic cell counts, sonde-based physicochemical analyses, and assays of all inorganic and organic nitrogen and phosphorus forms and fractions. The qPCR assays explained the greatest variation in observed geosmin (adjusted R2 = 0.71) and microcystin (adjusted R2 = 0.84) concentrations over the study period, highlighting their potential for routine monitoring applications. The origin of the monoterpene cyclase required for MIB biosynthesis was putatively linked to a periphytic cyanobacterial mat attached to the concrete drinking water inflow structure. We conclude that shotgun metagenomics can be used to identify microbial agents involved in water quality deterioration and to guide PCR assay selection or design for routine monitoring purposes. Finally, we offer estimates of microbial diversity and metagenomic coverage of our data sets for reference to others wishing to apply shotgun metagenomics to other lacustrine systems. IMPORTANCE Cyanobacterial toxins and microbial taste-and-odor compounds are a growing concern for drinking water utilities reliant upon surface water resources. Specific identification of the microorganism(s) responsible for water quality degradation is often complicated by the presence of co-occurring taxa capable of producing these undesirable metabolites. Here we present a framework for how shotgun metagenomics can be used to definitively identify problematic microorganisms and how these data can guide the development of rapid genetic assays for routine monitoring purposes. PMID:27342564

An Approach for Assessing the Signature Quality of Various Chemical Assays when Predicting the Culture Media Used to Grow Microorganisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holmes, Aimee E.; Sego, Landon H.; Webb-Robertson, Bobbie-Jo M.

We demonstrate an approach for assessing the quality of a signature system designed to predict the culture medium used to grow a microorganism. The system was comprised of four chemical assays designed to identify various ingredients that could be used to produce the culture medium. The analytical measurements resulting from any combination of these four assays can be used in a Bayesian network to predict the probabilities that the microorganism was grown using one of eleven culture media. We evaluated combinations of the signature system by removing one or more of the assays from the Bayes network. We measured andmore » compared the quality of the various Bayes nets in terms of fidelity, cost, risk, and utility, a method we refer to as Signature Quality Metrics« less

Extracellular Microbial Metabolomics: The State of the Art

PubMed Central

Villas-Boas, Silas G.

2017-01-01

Microorganisms produce and secrete many primary and secondary metabolites to the surrounding environment during their growth. Therefore, extracellular metabolites provide important information about the changes in microbial metabolism due to different environmental cues. The determination of these metabolites is also comparatively easier than the extraction and analysis of intracellular metabolites as there is no need for cell rupture. Many analytical methods are already available and have been used for the analysis of extracellular metabolites from microorganisms over the last two decades. Here, we review the applications and benefits of extracellular metabolite analysis. We also discuss different sample preparation protocols available in the literature for both types (e.g., metabolites in solution and in gas) of extracellular microbial metabolites. Lastly, we evaluate the authenticity of using extracellular metabolomics data in the metabolic modelling of different industrially important microorganisms. PMID:28829385

Extracellular Microbial Metabolomics: The State of the Art.

PubMed

Pinu, Farhana R; Villas-Boas, Silas G

2017-08-22

Microorganisms produce and secrete many primary and secondary metabolites to the surrounding environment during their growth. Therefore, extracellular metabolites provide important information about the changes in microbial metabolism due to different environmental cues. The determination of these metabolites is also comparatively easier than the extraction and analysis of intracellular metabolites as there is no need for cell rupture. Many analytical methods are already available and have been used for the analysis of extracellular metabolites from microorganisms over the last two decades. Here, we review the applications and benefits of extracellular metabolite analysis. We also discuss different sample preparation protocols available in the literature for both types (e.g., metabolites in solution and in gas) of extracellular microbial metabolites. Lastly, we evaluate the authenticity of using extracellular metabolomics data in the metabolic modelling of different industrially important microorganisms.

TOF-SIMS investigation of Streptomyces coelicolor, a mycelial bacterium

NASA Astrophysics Data System (ADS)

Vaidyanathan, Seetharaman; Fletcher, John S.; Lockyer, Nicholas P.; Vickerman, John C.

2008-12-01

Streptomyces coelicolor is a mycelial microorganism that produces several secondary metabolites, including antibiotics. The physiology of the organism has largely been investigated in liquid cultures due to ease of monitoring different physiological parameters and more homogeneous culture conditions. However, solid cultures reflect the natural physiology of the microorganism better, given that in its natural state it grows in the soil. Imaging mass spectrometry with TOF-SIMS and C 60+ primary ion beams offers a potential route to studying chemical changes at the molecular level, both intracellular and extracellular that can help in understanding the natural physiology of the microorganism. Here, we report the application of the technique for studying the lateral distribution of the chemical species detected in a population, grown in both liquid and solid cultures. The capability of the technique for studying biological systems with minimal system intervention is demonstrated.

Role and functions of beneficial microorganisms in sustainable aquaculture.

PubMed

Zhou, Qunlan; Li, Kangmin; Jun, Xie; Bo, Liu

2009-08-01

This paper aims to review the development of scientific concepts of microecology and ecology of microbes and the role and functions of beneficial microorganisms in aquaculture and mariculture. Beneficial microorganisms play a great role in natural and man-made aquatic ecosystems based on the co-evolution theory in living biosphere on earth. Their functions are to adjust algal population in water bodies so as to avoid unwanted algal bloom; to speed up decomposition of organic matter and to reduce CODmn, NH3-N and NO2-N in water and sediments so as to improve water quality; to suppress fish/shrimp diseases and water-borne pathogens; to enhance immune system of cultured aquatic animals and to produce bioactive compounds such as vitamins, hormones and enzymes that stimulate growth, thus to decrease the FCR of feed.

Characterization of microbial communities in subsurface nuclear blast cavities of the Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moser, Duane P; Czerwinski, Ken; Russell, Charles E

2010-07-13

This US Department of Energy (DOE) Environmental Remediation Sciences Project (ERSP) was designed to test fundamental hypotheses concerning the existence and nature of indigenous microbial populations of Nevada Test Site subsurface nuclear test/detonation cavities. Now called Subsurface Biogeochemical Research (SBR), this program's Exploratory Research (ER) element, which funded this research, is designed to support high risk, high potential reward projects. Here, five cavities (GASCON, CHANCELLOR, NASH, ALEMAN, and ALMENDRO) and one tunnel (U12N) were sampled using bailers or pumps. Molecular and cultivation-based techniques revealed bacterial signatures at five sites (CHANCELLOR may be lifeless). SSU rRNA gene libraries contained diverse andmore » divergent microbial sequences affiliated with known metal- and sulfur-cycling microorganisms, organic compound degraders, microorganisms from deep mines, and bacteria involved in selenate reduction and arsenite oxidation. Close relatives of Desulforudis audaxviator, a microorganism thought to subsist in the terrestrial deep subsurface on H2 and SO42- produced by radiochemical reactions, was detected in the tunnel waters. NTS-specific media formulations were used to culture and quantify nitrate-, sulfate-, iron-reducing, fermentative, and methanogenic microorganisms. Given that redox manipulations mediated by microorganisms can impact the mobility of DOE contaminants, our results should have implications for management strategies at this and other DOE sites.« less

Characterization of Microbial Communities in Subsurface Nuclear Blast Cavities of the Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moser, Duane P.; Bruckner, Jim; Fisher, Jen

2010-09-01

This U.S. Department of Energy (DOE) Environmental Remediation Sciences Project (ERSP) was designed to test fundamental hypotheses concerning the existence and nature of indigenous microbial populations of Nevada Test Site subsurface nuclear test/detonation cavities. Now called Subsurface Biogeochemical Research (SBR), this program’s Exploratory Research (ER) element, which funded this research, is designed to support high risk, high potential reward projects. Here, five cavities (GASCON, CHANCELLOR, NASH, ALEMAN, and ALMENDRO) and one tunnel (U12N) were sampled using bailers or pumps. Molecular and cultivation-based techniques revealed bacterial signatures at five sites (CHANCELLOR may be lifeless). SSU rRNA gene libraries contained diverse andmore » divergent microbial sequences affiliated with known metal- and sulfur-cycling microorganisms, organic compound degraders, microorganisms from deep mines, and bacteria involved in selenate reduction and arsenite oxidation. Close relatives of Desulforudis audaxviator, a microorganism thought to subsist in the terrestrial deep subsurface on H2 and SO42- produced by radiochemical reactions, was detected in the tunnel waters. NTS-specific media formulations were used to culture and quantify nitrate-, sulfate-, iron-reducing, fermentative, and methanogenic microorganisms. Given that redox manipulations mediated by microorganisms can impact the mobility of DOE contaminants, our results should have implications for management strategies at this and other DOE sites.« less

Conversion of Amazon rainforest to agriculture alters community traits of methane-cycling organisms.

PubMed

Meyer, Kyle M; Klein, Ann M; Rodrigues, Jorge L M; Nüsslein, Klaus; Tringe, Susannah G; Mirza, Babur S; Tiedje, James M; Bohannan, Brendan J M

2017-03-01

Land use change is one of the greatest environmental impacts worldwide, especially to tropical forests. The Amazon rainforest has been subject to particularly high rates of land use change, primarily to cattle pasture. A commonly observed response to cattle pasture establishment in the Amazon is the conversion of soil from a methane sink in rainforest, to a methane source in pasture. However, it is not known how the microorganisms that mediate methane flux are altered by land use change. Here, we use the deepest metagenomic sequencing of Amazonian soil to date to investigate differences in methane-cycling microorganisms and their traits across rainforest and cattle pasture soils. We found that methane-cycling microorganisms responded to land use change, with the strongest responses exhibited by methane-consuming, rather than methane-producing, microorganisms. These responses included a reduction in the relative abundance of methanotrophs and a significant decrease in the abundance of genes encoding particulate methane monooxygenase. We also observed compositional changes to methanotroph and methanogen communities as well as changes to methanotroph life history strategies. Our observations suggest that methane-cycling microorganisms are vulnerable to land use change, and this vulnerability may underlie the response of methane flux to land use change in Amazon soils. © 2017 John Wiley & Sons Ltd.

New insights about antibiotic production by Pseudomonas aeruginosa: a gene expression analysis

NASA Astrophysics Data System (ADS)

Gionco, Bárbara; Tavares, Eliandro R.; de Oliveira, Admilton G.; Yamada-Ogatta, Sueli F.; do Carmo, Anderson O.; Pereira, Ulisses de Pádua; Chideroli, Roberta T.; Simionato, Ane S.; Navarro, Miguel O. P.; Chryssafidis, Andreas L.; Andrade, Galdino

2017-09-01

The bacterial resistance for antibiotics is one of the most important problems in public health and only a small number of new products are in development. Antagonistic microorganisms from soil are a promising source of new candidate molecules. Products of secondary metabolism confer adaptive advantages for their producer, in the competition for nutrients in the microbial community. The biosynthesis process of compounds with antibiotic activity is the key to optimize their production and the transcriptomic study of microorganisms is of great benefit for the discovery of these metabolic pathways. Pseudomonas aeruginosa LV strain growing in the presence of copper chloride produces a bioactive organometallic compound, which has a potent antimicrobial activity against various microorganisms. The objective of this study was to verify overexpressed genes and evaluate their relation to the organometallic biosynthesis in this microorganism. P. aeruginosa LV strain was cultured in presence and absence of copper chloride. Two methods were used for transcriptomic analysis, genome reference-guided assembly and de novo assembly. The genome referenced analysis identified nine upregulated genes when bacteria were exposed to copper chloride, while the De Novo Assembly identified twelve upregulated genes. Nineteen genes can be related to an increased microbial metabolism for the extrusion process of exceeding intracellular copper. Two important genes are related to the biosynthesis of phenazine and tetrapyrroles compounds, which can be involved in the bioremediation of intracellular copper and biosynthesis of the organometallic compound. Additional studies are being carried out to further prove the function of the described genes and relate them to the biosynthetic pathway of the organometallic compound.

Effects of estrogen administration on the colonization capability of lactobacilli and Escherichia coli in the urinary tracts of mice.

PubMed

Silva, Clara; Rey, Rosario; Elena Nader-Macías, María

2004-01-01

The use of probiotic microorganisms has been widely promoted in the last 20 yr. They have been used in the gastrointestinal tract as capsules or as fermented milks. The characteristics of the strains proposed as probiotics have been published or patented under an elaboration process. The first step in designing a probiotic product is to isolate and characterize strains with some beneficial properties. The second step is to determine the optimal conditions to obtain the highest amount of viable microorganisms, together with the study of the best conditions to produce antagonistic substances. Urinary tract infections (UTIs) constitute a common cause of illness in pre- and postmenopausal women. It was estimated that 40-50% of adult women suffer a cystitis during their life. Ninety percent of acquired ambulatory UTIs and 30% of nosocomial infections are produced by Escherichia coli. The healthy human urinary tract is free of microorganisms, except for the anterior urethra, which is colonized by indigenous microbiota. The vaginal environment is a dynamic and complex ecological system with a highly heterogeneous microflora; thus favorable conditions exist for the colonization process, which is also affected by factors external to the tissues. The distal urethra and periurethral areas are separated ecological niches, both covered by the vaginal secretions that contain approx 109 microorganisms/mL. In these secretions, members of the genus Lactobacillus are predominant. Bacterial colonization does not increase because of the urinary flux, which clears the bacterial cells from the outer surfaces, as well as other factors such as pH, osmolarity, and urea concentration.

Anaerobic ethylene glycol degradation by microorganisms in poplar and willow rhizospheres.

PubMed

Carnegie, D; Ramsay, J A

2009-07-01

Although aerobic degradation of ethylene glycol is well documented, only anaerobic biodegradation via methanogenesis or fermentation has been clearly shown. Enhanced ethylene glycol degradation has been demonstrated by microorganisms in the rhizosphere of shallow-rooted plants such as alfalfa and grasses where conditions may be aerobic, but has not been demonstrated in the deeper rhizosphere of poplar or willow trees where conditions are more likely to be anaerobic. This study evaluated ethylene glycol degradation under nitrate-, and sulphate-reducing conditions by microorganisms from the rhizosphere of poplar and willow trees planted in the path of a groundwater plume containing up to 1.9 mol l(-1) (120 g l(-1)) ethylene glycol and, the effect of fertilizer addition when nitrate or sulphate was provided as a terminal electron acceptor (TEA). Microorganisms in these rhizosphere soils degraded ethylene glycol using nitrate or sulphate as TEAs at close to the theoretical stoichiometric amounts required for mineralization. Although the added nitrate or sulphate was primarily used as TEA, TEAs naturally present in the soil or CO(2) produced from ethylene glycol degradation were also used, demonstrating multiple TEA usage. Anaerobic degradation produced acetaldehyde, less acetic acid, and more ethanol than under aerobic conditions. Although aerobic degradation rates were faster, close to 100% disappearance was eventually achieved anaerobically. Degradation rates under nitrate-reducing conditions were enhanced upon fertilizer addition to achieve rates similar to aerobic degradation with up to 19.3 mmol (1.20 g) of ethylene glycol degradation l(-1) day(-1) in poplar soils. This is the first study to demonstrate that microorganisms in the rhizosphere of deep rooted trees like willow and poplar can anaerobically degrade ethylene glycol. Since anaerobic biodegradation may significantly contribute to the phytoremediation of ethylene glycol in the deeper subsurface, the need for "pump and treat" or an aerobic treatment would be eliminated, hence reducing the cost of treatment.

Acquired immune deficiency syndrome (AIDS) in Brazil. Necropsy findings.

PubMed

Michalany, J; Mattos, A L; Michalany, N S; Filie, A C; Montezzo, L C

1987-01-01

According to the 15 autopsies performed at the Department of Pathological Anatomy, Escola Paulista de Medicina, São Paulo, Brazil, it was confirmed that acquired immunodeficiency syndrome (AIDS) occurs preferably in young homosexual males, who die in a short period of time of the disease, which leads to a consumptive state verified by cachexia of the cadavers. The most affected organs of this series were the lungs and encephalum, exactly the ones responsible for the immediate cause of death. In this series of autopsies there were 9 types of microorganisms represented by virus, bacteria, fungi, protozoans and two types of tumors, Kaposi's sarcoma and lymphoma of the central nervous system. From the microorganisms, the most frequent was the Cytomegalovirus and, from the tumors, Kaposi's sarcoma. The various types of microorganisms were frequently associated, principally in the central nervous and digestive systems. There was also association of microorganisms with tumors. Besides the lesions produced by microorganisms there were other associated alterations as brown atrophy of neuronia, which was related to the infiltration of cerebral lymphoma, and the lymphocytic depletion of lymphoid organs due to immunological exhaustion. Cellular reaction to microorganisms was practically none, principally with Pneumocystis carinii and Cryptococcus neoformans, the first one behaving as an inert mould in the pulmonary alveoli and the second proliferating freely in tissues. In two cases there was no granulomatous reaction to Mycobacterium tuberculosis. The primary lymphoma of the central nervous system should be interpreted as a microglioma, i.e., a reticulosarcoma of this system according to Hortega's school.

Electricity generation from an inorganic sulfur compound containing mining wastewater by acidophilic microorganisms.

PubMed

Ni, Gaofeng; Christel, Stephan; Roman, Pawel; Wong, Zhen Lim; Bijmans, Martijn F M; Dopson, Mark

2016-09-01

Sulfide mineral processing often produces large quantities of wastewaters containing acid-generating inorganic sulfur compounds. If released untreated, these wastewaters can cause catastrophic environmental damage. In this study, microbial fuel cells were inoculated with acidophilic microorganisms to investigate whether inorganic sulfur compound oxidation can generate an electrical current. Cyclic voltammetry suggested that acidophilic microorganisms mediated electron transfer to the anode, and that electricity generation was catalyzed by microorganisms. A cation exchange membrane microbial fuel cell, fed with artificial wastewater containing tetrathionate as electron donor, reached a maximum whole cell voltage of 72 ± 9 mV. Stepwise replacement of the artificial anolyte with real mining process wastewater had no adverse effect on bioelectrochemical performance and generated a maximum voltage of 105 ± 42 mV. 16S rRNA gene sequencing of the microbial consortia resulted in sequences that aligned within the genera Thermoplasma, Ferroplasma, Leptospirillum, Sulfobacillus and Acidithiobacillus. This study opens up possibilities to bioremediate mining wastewater using microbial fuel cell technology. Copyright © 2016 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Early Discrimination Of Microorganisms Involved In Ventilator Associated Pneumonia Using Qualitative Volatile Fingerprints

NASA Astrophysics Data System (ADS)

Planas, Neus; Kendall, Catherine; Barr, Hugh; Magan, Naresh

2009-05-01

This study has examined the use of an electronic nose for the detection of volatile organic compounds produced by different microorganisms responsible for ventilator-associated pneumonia (VAP), an important disease among patients who require mechanical ventilation. Based on the analysis of the volatile organic compounds, electronic nose technology is being evaluated for the early detection and identification of many diseases. It has been shown that effective discrimination of two bacteria (Enterobacter cloacae and Klebsiella pneumoniae) and yeast (Candida albicans), could be obtained after 24 h and filamentous fungus (Aspergillus fumigatus) after 72 h. Discrimination between blank samples and those with as initial concentration of 102 CFU ml-1 was shown with 24 h incubation for bacteria and 48 h for fungi. Effective discrimination between all the species was achieved 72 h after incubation. Initial studies with mixtures of microorganisms involved in VAP suggest that complex interactions between species occur which influences the ability to differentiate dominant species using volatile production patterns. A nutrient agar base medium was found to be optimum for early discrimination between two microorganisms (Klebsiella pneumoniae and Candida albicans).

Efflux as a mechanism of antimicrobial drug resistance in clinical relevant microorganisms: the role of efflux inhibitors.

PubMed

Willers, Clarissa; Wentzel, Johannes Frederik; du Plessis, Lissinda Hester; Gouws, Chrisna; Hamman, Josias Hendrik

2017-01-01

Microbial resistance against antibiotics is a serious threat to the effective treatment of infectious diseases. Several mechanisms exist through which microorganisms can develop resistance against antimicrobial drugs, of which the overexpression of genes to produce efflux pumps is a major concern. Several efflux transporters have been identified in microorganisms, which infer resistance against specific antibiotics and even multidrug resistance. Areas covered: This paper focuses on microbial resistance against antibiotics by means of the mechanism of efflux and gives a critical overview of studies conducted to overcome this problem by combining efflux pump inhibitors with antibiotics. Information was obtained from a literature search done with MEDLINE, Pubmed, Scopus, ScienceDirect, OneSearch and EBSCO host. Expert opinion: Efflux as a mechanism of multidrug resistance has presented a platform for improved efficacy against resistant microorganisms by co-administration of efflux pump inhibitors with antimicrobial agents. Although proof of concept has been shown for this approach with in vitro experiments, further research is needed to develop more potent inhibitors with low toxicity which is clinically effective.

Water Supplies: Microbiological Analysis

EPA Science Inventory

Producing high-quality drinking water that is free of harmful microorganisms and maintaining its purity through distribution systems are essential for public health. Drinking water quality standards and guidelines for microbial contaminants vary within and among countries but typ...

Methods for producing 3-hydroxypropionic acid and other products

DOEpatents

Lynch, Michael D.; Gill, Ryan T.; Lipscomb, Tanya E. W.

2016-07-12

This invention relates to metabolically engineered microorganism strains, such as bacterial strains, in which there is an increased utilization of malonyl-CoA for production of a chemical product, which includes 3-hydroxypropionic acid.

Decoupling energy and power

NASA Astrophysics Data System (ADS)

Grattieri, Matteo; Minteer, Shelley D.

2018-01-01

Biological photovoltaic devices (BPVs) use photosynthetic microorganisms to produce electricity, but low photocurrent generation impedes their application. Now, a micro-scale flow-based BPV system is reported with power density outputs similar to that of large-scale biofuels.

Method for producing 3-hydroxypropionic acid and other products

DOEpatents

Lynch, Michael D.; Gill, Ryan T.; Lipscomb, Tanya E.W.

2016-08-30

This invention relates to metabolically engineered microorganism strains, such as bacterial strains, in which there is an increased utilization of malonyl-CoA for production of a chemical product, which includes 3-hydroxypropionic acid.

Ultra-high-pressure homogenization (UHPH) system for producing high-quality vegetable-based beverages: physicochemical, microbiological, nutritional and toxicological characteristics.

PubMed

Ferragut, Victoria; Hernández-Herrero, Manuela; Veciana-Nogués, María Teresa; Borras-Suarez, Miquel; González-Linares, Javier; Vidal-Carou, María Carmen; Guamis, Buenaventura

2015-03-30

A relatively new technology based on a continuous system of ultra-high-pressure homogenization (UHPH) was used for producing high-quality soy and almond beverages as an alternative to conventional heat treatments (pasteurization and UHT). The aim of this study was to compare those treatments by analyzing the most relevant quality parameters with a broad vision from the production to the potential toxicological changes, passing through the main nutritional characteristics. UHPH treatment at 200 MPa, 55 °C T(in) produced a higher reduction of microorganisms than pasteurization. UHPH treatment at 300 MPa, 75 °C T(in) led to complete inactivation of microorganisms, similar to UHT treatment. A much better colloidal stability was observed in both UHPH-treated almond and soy beverages compared with those processed by conventional heat treatments. UHPH treatments led to the same increase in digestibility as heat treatments and did not produce a reduction in the availability of lysine. In addition, UHPH samples of soy beverage seem to be less allergenic based on their lower gut immune response in comparison with heat-treated samples. UHPH treatments could be used to produce high-quality commercial vegetable beverages with different quality standards (fresh or long-life storage) according to consumer preference. © 2014 Society of Chemical Industry.

Poly-β-hydroxybutyrate and exopolysaccharide biosynthesis by bacterial isolates from pigeonpea [Cajanus cajan (L.) Millsp] root nodules.

PubMed

Fernandes, Paulo Ivan; de Oliveira, Paulo Jansen; Rumjanek, Norma Gouvêa; Xavier, Gustavo Ribeiro

2011-02-01

The bacterial strains that are able to produce biopolymers that are applied in industrial sectors present a source of renewable resources. Some microorganisms are already applied at several industrial sectors, but the prospecting of new microbes must bring microorganisms that are feasible to produce interesting biopolymers more efficiently and in cheaper conditions. Among the biopolymers applied industrially, polyhydroxybutyrate (PHB) and exopolysaccharides (EPS) stand out because of its applications, mainly in biodegradable plastic production and in food industry, respectively. In this context, the capacity of bacteria isolated from pigeonpea root nodules to produce EPS and PHB was evaluated, as well as the cultural characterization of these isolates. Among the 38 isolates evaluated, the majority presented fast growth and ability to acidify the culture media. Regarding the biopolymer production, five isolates produced more than 10 mg PHB per liter of culture medium. Six EPS producing bacteria achieved more than 200 mg EPS per liter of culture medium. Evaluating different carbon sources, the PHB productivity of the isolate 24.6b reached 69% of cell dry weight when cultured with starch as sole carbon source, and the isolate 8.1c synthesized 53% PHB in dry cell biomass and more than 1.3 g L⁻¹ of EPS when grown using xylose as sole carbon source.

Alkaline tolerant dextranase from streptomyces anulatus

DOEpatents

Decker, Stephen R.; Adney, William S.; Vinzant, Todd B.; Himmel, Michael E.

2003-01-01

A process for production of an alkaline tolerant dextranase enzyme comprises culturing a dextran-producing microorganism Streptomyces anulatus having accession no. ATCC PTA-3866 to produce an alkaline tolerant dextranase, Dex 1 wherein the protein in said enzyme is characterized by a MW of 63.3 kDa and Dex 2 wherein its protein is characterized by a MW of 81.8 kDa.

Nitration Enzyme Toolkit for the Biosynthesis of Energetic Materials

DTIC Science & Technology

by - products that degrade performance of the energetic products . To reduce the...bionitration mechanisms used by microorganisms to produce nitro-containing natural products . We investigated biosynthetic pathways for 2-nitroimidazole...producing a diverse set of nitrophenols. This growing bionitration toolkit represents a diverse range of nitration mechanisms and products that can be adapted for the green chemistry production of nitro compounds and

Potential of bacteriocin-producing lactic acid bacteria for safety improvements of traditional Thai fermented meat and human health.

PubMed

Swetwiwathana, Adisorn; Visessanguan, Wonnop

2015-11-01

Lactic acid bacteria (LAB) are very important in converting of agricultural products into safe, delicious and shelf stable foods for human consumption. The preservative activity of LAB in foods is mainly attributed to the production of anti-microbial metabolites such as organic acids and bacteriocins which enables them to grow and control the growth of pathogens and spoilage microorganisms. Besides ensuring safety, bacteriocin-producing LAB with their probiotic potentials could also be emerging as a means to develop functional meat products with desirable health benefits. Nevertheless, to be qualified as a candidate probiotic culture, other prerequisite probiotic properties of bacteriocin-producing LAB have to be assessed according to regulatory guidelines for probiotics. Nham is an indigenous fermented sausage of Thailand that has gained popularity and acceptance among Thais. Since Nham is made from raw meat and is usually consumed without cooking, risks due to undesirable microorganisms such as Salmonella spp., Staphylococcus aureus, and Listeria monocytogenes, are frequently observed. With an ultimate goal to produce safer and healthier product, our research attempts on the development of a variety of new Nham products are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme.

PubMed

Sherkhanov, Saken; Korman, Tyler P; Clarke, Steven G; Bowie, James U

2016-04-07

Most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase, Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase (DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes.

Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme

DOE PAGES

Sherkhanov, Saken; Korman, Tyler P.; Clarke, Steven G.; ...

2016-04-07

Here, most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase,more » Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase ( DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes.« less

Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sherkhanov, Saken; Korman, Tyler P.; Clarke, Steven G.

Here, most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase,more » Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase ( DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes.« less

Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme

PubMed Central

Sherkhanov, Saken; Korman, Tyler P.; Clarke, Steven G; Bowie, James U.

2016-01-01

Most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase, Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase (DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes. PMID:27053100

Microbial contamination of contact lenses, lens care solutions, and their accessories: a literature review.

PubMed

Szczotka-Flynn, Loretta B; Pearlman, Eric; Ghannoum, Mahmoud

2010-03-01

A contact lens (CL) can act as a vector for microorganisms to adhere to and transfer to the ocular surface. Commensal microorganisms that uneventfully cohabitate on lid margins and conjunctivae and potential pathogens that are found transiently on the ocular surface can inoculate CLs in vivo. In the presence of reduced tissue resistance, these resident microorganisms or transient pathogens can invade and colonize the cornea or conjunctiva to produce inflammation or infection. The literature was reviewed and used to summarize the findings over the last 30 years on the identification, enumeration, and classification of microorganisms adherent to CLs and their accessories during the course of normal wear and to hypothesize the role that these microorganisms play in CL infection and inflammation. Lens handling greatly increases the incidence of lens contamination, and the ocular surface has a tremendous ability to destroy organisms. However, even when removed aseptically from the eye, more than half of lenses are found to harbor microorganisms, almost exclusively bacteria. Coagulase-negative Staphylococci are most commonly cultured from worn lenses; however, approximately 10% of lenses harbor Gram-negative and highly pathogenic species, even in asymptomatic subjects. In storage cases, the incidence of positive microbial bioburden is also typically greater than 50%. All types of care solutions can become contaminated, including up to 30% of preserved products. The process of CL-related microbial keratitis and inflammation is thought to be preceded by the presence or transfer or both of microorganisms from the lens to the ocular surface. Thus, this detailed understanding of lens-related bioburden is important in the understanding of factors associated with infectious and inflammatory complications. Promising mechanisms to prevent bacterial colonization on lenses and lens cases are forthcoming, which may decrease the incidence of microbially driven CL complications.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kreuzer-Martin, Helen W.; Hegg, Eric L.

The use of isotopic signatures for forensic analysis of biological materials is well-established, and the same general principles that apply to interpretation of stable isotope content of C, N, O, and H apply to the analysis of microorganisms. Heterotrophic microorganisms derive their isotopic content from their growth substrates, which are largely plant and animal products, and the water in their culture medium. Thus the isotope signatures of microbes are tied to their growth environment. The C, N, O, and H isotope ratios of spores have been demonstrated to constitute highly discriminating signatures for sample matching. They can rule out specificmore » samples of media and/or water as possible production media, and can predict isotope ratio ranges of the culture media and water used to produce a given sample. These applications have been developed and tested through analyses of approximately 250 samples of Bacillus subtilis spores and over 500 samples of culture media, providing a strong statistical basis for data interpretation. A Bayesian statistical framework for integrating stable isotope data with other types of signatures derived from microorganisms has been able to characterize the culture medium used to produce spores of various Bacillus species, leveraging isotopic differences in different medium types and demonstrating the power of data integration for forensic investigations.« less

Role of secondary metabolites in the interaction between Pseudomonas fluorescens and soil microorganisms under iron-limited conditions

PubMed Central

Deveau, Aurélie; Gross, Harald; Palin, Béatrice; Mehnaz, Samina; Schnepf, Max; Leblond, Pierre; Dorrestein, Pieter C.; Aigle, Bertrand

2016-01-01

Microorganisms can be versatile in their interactions with each other, being variously beneficial, neutral or antagonistic in their effect. Although this versatility has been observed among many microorganisms and in many environments, little is known regarding the mechanisms leading to these changes in behavior. In the present work, we analyzed the mechanism by which the soil bacterium Pseudomonas fluorescens BBc6R8 shifts from stimulating the growth of the ectomycorrhizal fungus Laccaria bicolor S238N to killing the fungus. We show that among the three secondary metabolites produced by the bacterial strain—the siderophores enantio-pyochelin and pyoverdine, and the biosurfactant viscosin—the siderophores are mainly responsible for the antagonistic activity of the bacterium under iron-limited conditions. While the bacterial strain continues to produce beneficial factors, their effects are overridden by the action of their siderophores. This antagonistic activity of the strain P. fluorescens BBC6R8 in iron-depleted environments is not restricted to its influence on L. bicolor, since it was also seen to inhibit the growth of the actinomycete Streptomyces ambofaciens ATCC23877. We show that the strain P. fluorescens BBc6R8 uses different strategies to acquire iron, depending on certain biotic and abiotic factors. PMID:27199346

Antibiosis of vineyard ecosystem fungi against food-borne microorganisms.

PubMed

Cueva, Carolina; Moreno-Arribas, M Victoria; Bartolomé, Begoña; Salazar, Óscar; Vicente, M Francisca; Bills, Gerald F

2011-12-01

Fermentation extracts from fungi isolated from vineyard ecosystems were tested for antimicrobial activities against a set of test microorganisms, including five food-borne pathogens (Staphylococcus aureus EP167, Acinetobacter baumannii (clinically isolated), Pseudomonas aeruginosa PAO1, Escherichia coli O157:H7 (CECT 5947) and Candida albicans MY1055) and two probiotic bacteria (Lactobacillus plantarum LCH17 and Lactobacillus brevis LCH23). A total of 182 fungi was grown in eight different media, and the fermentation extracts were screened for antimicrobial activity. A total of 71 fungi produced extracts active against at least one pathogenic microorganism, but not against any probiotic bacteria. The Gram-positive bacterium S. aureus EP167 was more susceptible to antimicrobial fungi broth extracts than Gram-negative bacteria and pathogenic fungi. Identification of active fungi based on internal transcribed spacer rRNA sequence analysis revealed that species in the orders Pleosporales, Hypocreales and Xylariales dominated. Differences in antimicrobial selectivity were observed among isolates from the same species. Some compounds present in the active extracts were tentatively identified by liquid chromatography-mass spectrometry. Antimicrobial metabolites produced by vineyard ecosystem fungi may potentially limit colonization and spoilage of food products by food-borne pathogens, with minimal effect on probiotic bacteria. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Sequence-based analysis of the microbial composition of water kefir from multiple sources.

PubMed

Marsh, Alan J; O'Sullivan, Orla; Hill, Colin; Ross, R Paul; Cotter, Paul D

2013-11-01

Water kefir is a water-sucrose-based beverage, fermented by a symbiosis of bacteria and yeast to produce a final product that is lightly carbonated, acidic and that has a low alcohol percentage. The microorganisms present in water kefir are introduced via water kefir grains, which consist of a polysaccharide matrix in which the microorganisms are embedded. We aimed to provide a comprehensive sequencing-based analysis of the bacterial population of water kefir beverages and grains, while providing an initial insight into the corresponding fungal population. To facilitate this objective, four water kefirs were sourced from the UK, Canada and the United States. Culture-independent, high-throughput, sequencing-based analyses revealed that the bacterial fraction of each water kefir and grain was dominated by Zymomonas, an ethanol-producing bacterium, which has not previously been detected at such a scale. The other genera detected were representatives of the lactic acid bacteria and acetic acid bacteria. Our analysis of the fungal component established that it was comprised of the genera Dekkera, Hanseniaspora, Saccharomyces, Zygosaccharomyces, Torulaspora and Lachancea. This information will assist in the ultimate identification of the microorganisms responsible for the potentially health-promoting attributes of these beverages. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

IMPROVED POLLUTANT MANAGEMENT IN URBAN STORMWATER BMPS

EPA Science Inventory

Increased urbanization has resulted in a larger percentage of impervious areas that produce large quantities of stormwater runoff and contribute significant amounts of debris and pollutants (e.g., litter, oils, heavy metals, sediments, nutrients, organic matter, and microorganism...

21 CFR 500.35 - Animal feeds contaminated with Salmonella microorganisms.

Code of Federal Regulations, 2013 CFR

2013-04-01

... and Drug Administration, the Centers for Disease Control of the U.S. Public Health Service, the Animal... producing infection and disease in animals must be regarded as an adulterant within the meaning of section...

21 CFR 500.35 - Animal feeds contaminated with Salmonella microorganisms.

Code of Federal Regulations, 2012 CFR

2012-04-01

... and Drug Administration, the Centers for Disease Control of the U.S. Public Health Service, the Animal... producing infection and disease in animals must be regarded as an adulterant within the meaning of section...

Exopolysaccharide hydrogels for corrosion inhibition

USDA-ARS?s Scientific Manuscript database

Exopolysaccharide production by micro-organisms have several industrial applications in food, pharmaceuticals, or other industries. Lactic acid bacteria such as Leuconostoc mesenteroides (LM) are endemic to the environment and produce extracellular polymeric glucans such as dextran. Dextrans cause s...

Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling

PubMed Central

Magennis, E. Peter; Fernandez-Trillo, Francisco; Sui, Cheng; Spain, Sebastian G.; Bradshaw, David; Churchley, David; Mantovani, Giuseppe; Winzer, Klaus; Alexander, Cameron

2014-01-01

The detection and inactivation of pathogenic strains of bacteria continues to be an important therapeutic goal. Hence, there is a need for materials that can bind selectively to specific microorganisms, for diagnostic or anti-infective applications, but which can be formed from simple and inexpensive building blocks. Here, we exploit bacterial redox systems to induce a copper-mediated radical polymerisation of synthetic monomers at cell surfaces, generating polymers in situ that bind strongly to the microorganisms which produced them. This ‘bacteria-instructed synthesis’ can be carried out with a variety of microbial strains, and we show that the polymers produced are self-selective binding agents for the ‘instructing’ cell types. We further expand on the bacterial redox chemistries to ‘click’ fluorescent reporters onto polymers directly at the surfaces of a range of clinical isolate strains, allowing rapid, facile and simultaneous binding and visualisation of pathogens. PMID:24813421

Gluconic acid produced by Gluconacetobacter diazotrophicus Pal5 possesses antimicrobial properties.

PubMed

Nieto-Peñalver, Carlos G; Savino, María J; Bertini, Elisa V; Sánchez, Leandro A; de Figueroa, Lucía I C

2014-09-01

Gluconic acid is produced in large quantities by the endophytic and diazotrophic bacterium Gluconacetobacter diazotrophicus Pal5. This organic acid derives from direct oxidation of glucose by a pyrroloquinoline-quinone-linked glucose dehydrogenase in this plant growth-promoting bacterium. In the present article, evidence is presented showing that gluconic acid is also responsible for the antimicrobial activity of G. diazotrophicus Pal5. The broad antagonistic spectrum includes Gram-positive and -negative bacteria. Eukaryotic microorganisms are more resistant to growth inhibition by this acid. Inhibition by gluconic acid can be modified through the presence of other organic acids. In contrast to other microorganisms, the Quorum Sensing system of G. diazotrophicus Pal5, a regulatory mechanism that plays a key role in several microbe-microbe interactions, is not related to gluconic acid production and the concomitant antagonistic activity. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling

NASA Astrophysics Data System (ADS)

Magennis, E. Peter; Fernandez-Trillo, Francisco; Sui, Cheng; Spain, Sebastian G.; Bradshaw, David J.; Churchley, David; Mantovani, Giuseppe; Winzer, Klaus; Alexander, Cameron

2014-07-01

The detection and inactivation of pathogenic strains of bacteria continues to be an important therapeutic goal. Hence, there is a need for materials that can bind selectively to specific microorganisms for diagnostic or anti-infective applications, but that can be formed from simple and inexpensive building blocks. Here, we exploit bacterial redox systems to induce a copper-mediated radical polymerization of synthetic monomers at cell surfaces, generating polymers in situ that bind strongly to the microorganisms that produced them. This ‘bacteria-instructed synthesis’ can be carried out with a variety of microbial strains, and we show that the polymers produced are self-selective binding agents for the ‘instructing’ cell types. We further expand on the bacterial redox chemistries to ‘click’ fluorescent reporters onto polymers directly at the surfaces of a range of clinical isolate strains, allowing rapid, facile and simultaneous binding and visualization of pathogens.

The photobiological production of hydrogen: potential efficiency and effectiveness as a renewable fuel.

PubMed

Prince, Roger C; Kheshgi, Haroon S

2005-01-01

Photosynthetic microorganisms can produce hydrogen when illuminated, and there has been considerable interest in developing this to a commercially viable process. Its appealing aspects include the fact that the hydrogen would come from water, and that the process might be more energetically efficient than growing, harvesting, and processing crops. We review current knowledge about photobiological hydrogen production, and identify and discuss some of the areas where scientific and technical breakthroughs are essential for commercialization. First we describe the underlying biochemistry of the process, and identify some opportunities for improving photobiological hydrogen production at the molecular level. Then we address the fundamental quantum efficiency of the various processes that have been suggested, technological issues surrounding large-scale growth of hydrogen-producing microorganisms, and the scale and efficiency on which this would have to be practiced to make a significant contribution to current energy use.

The Use of Xylanases from Different Microbial Origin in Bread Baking and Their Effects on Bread Qualities

NASA Astrophysics Data System (ADS)

Al-Widyan, Omar; Khataibeh, Moayad H.; Abu-Alruz, Khaled

Effects of xylanases on bread quality were examined. Enzymes used were endo-xylanase (EC 3.2.1.8) from different sources of microorganisms. Baked loaves were assessed for Loaves volume, colour and staling rate. Xylanases produced from rumen microorganisms M6 had clearly positive effects on loaf volume of bread as well as anti-firming potential. M3 (produced from Trichoderma longibrachiatum) improved crumb softness. The use of xylanase for breadmaking lowered firmness of bread crumb effectively compared with control loaf. It can be summarized that xylanases had significant positive effects on bread characteristics. In particular, they had advantage in retarding the staling rate of bread. It is recommended that the optimum dosage of enzymes, method of application in industrial scale especially with xylanase should be studied further in order to gain the great advantages of enzyme addition in breadmaking.

Conversion of cellulosic materials to sugar

DOEpatents

Wilke, Charles R.; Mitra, Gautam

1976-08-03

A process for the production of sugar, mainly glucose, by the enzymatic degradation of cellulosic materials, particularly cellulosic wastes, which comprises hydrolyzing the cellulosic material in the presence of cellulase enzyme to produce a sugar solution and recovering from the hydrolysis products a major proportion of the cellulase enzyme used in the hydrolysis reaction for re-use. At least a portion of the required makeup cellulase enzyme is produced in a two-stage operation wherein, in the first stage, a portion of the output sugar solution is utilized to grow a cellulase-secreting microorganism, and, in the second stage, cellulase enzyme formation is induced in the microorganism-containing culture medium by the addition of an appropriate inducer, such as a cellulosic material. Cellulase enzyme is precipitated from the culture liquid by the addition of an organic solvent material, such as a low molecular weight alkyl ketone or alcohol, and the cellulase precipitate is then fed to the hydrolysis reaction.

State of the art review of biofuels production from lignocellulose by thermophilic bacteria.

PubMed

Jiang, Yujia; Xin, Fengxue; Lu, Jiasheng; Dong, Weiliang; Zhang, Wenming; Zhang, Min; Wu, Hao; Ma, Jiangfeng; Jiang, Min

2017-12-01

Biofuels, including ethanol and butanol, are mainly produced by mesophilic solventogenic yeasts and Clostridium species. However, these microorganisms cannot directly utilize lignocellulosic materials, which are abundant, renewable and non-compete with human demand. More recently, thermophilic bacteria show great potential for biofuels production, which could efficiently degrade lignocellulose through the cost effective consolidated bioprocessing. Especially, it could avoid contamination in the whole process owing to its relatively high fermentation temperature. However, wild types thermophiles generally produce low levels of biofuels, hindering their large scale production. This review comprehensively summarizes the state of the art development of biofuels production by reported thermophilic microorganisms, and also concludes strategies to improve biofuels production including the metabolic pathways construction, co-culturing systems and biofuels tolerance. In addition, strategies to further improve butanol production are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

MicroRNAs as mediators of insect host-pathogen interactions and immunity.

PubMed

Hussain, Mazhar; Asgari, Sassan

2014-11-01

Insects are the most successful group of animals on earth, owing this partly to their very effective immune responses to microbial invasion. These responses mainly include cellular and humoral responses as well as RNA interference (RNAi). Small non-coding RNAs (snRNAs) produced through RNAi are important molecules in the regulation of gene expression in almost all living organisms; contributing to important processes such as development, differentiation, immunity as well as host-microorganism interactions. The main snRNAs produced by the RNAi response include short interfering RNAs, microRNAs and piwi-interacting RNAs. In addition to the host snRNAs, some microorganisms encode snRNAs that affect the dynamics of host-pathogen interactions. In this review, we will discuss the latest developments in regards to the role of microRNA in insect host-pathogen interactions and provide some insights into this rapidly developing area of research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Detrimental effect of increasing sugar concentrations on ethanol production from maize or decorticated sorghum mashes fermented with Saccharomyces cerevisiae or Zymomonas mobilis: biofuels and environmental biotechnology.

PubMed

Pérez-Carrillo, Esther; Luisa Cortés-Callejas, M; Sabillón-Galeas, Luis E; Montalvo-Villarreal, Jorge L; Canizo, Jesica R; Georgina Moreno-Zepeda, M; Serna-Saldivar, Sergio O

2011-02-01

The efficiency of ethanol fermentation, as affected by grain source (maize and decorticated red sorghum), total sugar concentration (13 or 20° Plato) and type of microorganism (Saccharomyces cerevisiae or Zymomonas mobilis) was studied. Maize mashes yielded 0.32 l ethanol kg(-1) ground grain whereas mashes prepared with decorticated red sorghum produced 0.28 l ethanol kg(-1). Both microorganisms yielded similar amounts of ethanol. However, high-gravity mashes (20° Plato) yielded lower amounts of ethanol compared to counterparts adjusted to 13° Plato (0.28 vs. 0.22 l ethanol kg(-1) ground grains). In decorticated sorghum mashes adjusted to 20° P, Z. mobilis produced 40 ml kg(-1) more ethanol compared to S. cerevisiae. In addition, Z. mobilis had a lower dependency on nitrogenous compounds.

Survey of Microbial Enzymes in Soil, Water, and Plant Microenvironments

PubMed Central

Alves, Priscila Divina Diniz; Siqueira, Flávia de Faria; Facchin, Susanne; Horta, Carolina Campolina Rebello; Victória, Júnia Maria Netto; Kalapothakis, Evanguedes

2014-01-01

Detection of microbial enzymes in natural environments is important to understand biochemical activities and to verify the biotechnological potential of the microorganisms. In the present report, 346 isolates from soil, water, and plants were screened for enzyme production (caseinase, gelatinase, amylase, carboxymethyl cellulase, and esterase). Our results showed that 89.6% of isolates produced at least one tested enzyme. A predominance of amylase in soil samples, carboxymethyl cellulase in plants, as well as esterase and gelatinase in water was observed. Interesting enzymatic profiles were found in some microenvironments, suggesting specificity of available nutrients and/or natural selection. This study revealed the potential of microorganisms present in water, soil, and plant to produce important enzymes for biotechnological exploration. A predominance of certain enzymes was found, depending on the type of environmental sample. The distribution of microbial enzymes in soil, water and plants has been little exploited in previous reports. PMID:24847390

Construction of an artificial symbiotic community using a Chlorella–symbiont association as a model

PubMed Central

Imase, Masato; Watanabe, Keiji; Aoyagi, Hideki; Tanaka, Hideo

2008-01-01

Chlorella sorokiniana IAM C-212 produces a polysaccharide gel, termed a sheath, under photoautotrophic conditions. The C. sorokiniana sheath is a suitable habitat for several symbiotic microorganisms because it ensures close proximity between the C. sorokiniana and symbionts. In this study, we established a method for increasing the volume of the sheath produced by C. sorokiniana, and proposed a method for constructing artificial communities of Chlorella and symbiotic microorganisms. The C. sorokiniana sheath was increased by addition of calcium chloride solution. The sheath resulted in coflocculation of C. sorokiniana and the associated symbiotic bacteria, thus strengthening the bacterial–Chlorella symbiotic association. An application of this technique was demonstrated by constructing a complex of C. sorokiniana and a propionate-degrading bacterium (PDS1). Although propionate inhibited the growth of axenic C. sorokiniana, the C. sorokiniana–PDS1 complex showed good growth in a medium containing a high concentration of propionate. PMID:18269632

Inhibition of biofouling by marine microorganisms and their metabolites.

PubMed

Dobretsov, Sergey; Dahms, Hans-Uwe; Qian, Peri-Yuan

2006-01-01

Development of microbial biofilms and the recruitment of propagules on the surfaces of man-made structures in the marine environment cause serious problems for the navies and for marine industries around the world. Current antifouling technology is based on the application of toxic substances that can be harmful to the natural environment. For this reason and the global ban of tributyl tin (TBT), there is a need for the development of "environmentally-friendly" antifoulants. Marine microbes are promising potential sources of non-toxic or less-toxic antifouling compounds as they can produce substances that inhibit not only the attachment and/or growth of microorganisms but also the settlement of invertebrate larvae and macroalgal spores. However, so far only few antilarval settlement compounds have been isolated and identified from bacteria. In this review knowledge about antifouling compounds produced by marine bacteria and diatoms are summarised and evaluated and future research directions are highlighted.

Cellulase producing microorganism ATCC 55702

DOEpatents

Dees, H. Craig

1997-01-01

Bacteria which produce large amounts of cellulase--containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualifies for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques.

Cellulase-containing cell-free fermentate produced from microorganism ATCC 55702

DOEpatents

Dees, H. Craig

1997-12-16

Bacteria which produce large amounts of cellulase-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques.

Cellulase producing microorganism ATCC 55702

DOEpatents

Dees, H.C.

1997-12-30

Bacteria which produce large amounts of cellulase--containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualifies for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques. 5 figs.

STUDIES ON NON-HEMOLYTIC STREPTOCOCCI ISOLATED FROM THE RESPIRATORY TRACT OF MAN

PubMed Central

Horsfall, Frank L.

1951-01-01

The type specific immunological properties of certain non-hemolytic streptococci, including Str. salivarius type I and type II, present in the respiratory tract of human beings appear to be dependent upon the presence of capsular polysaccharides. The levans formed from sucrose by Str. salivarius (encapsulated S cells or non-encapsulated R variants), or by cell-free enzymes derived from these microorganisms, are indistinguishable immunologically and show no evidence of type specificity. Such levans appear to be immunologically distinct from and unrelated to the capsular polysaccharides of the microorganisms which produce them. PMID:14824398

Method of producing a cellulase-containing cell-free fermentate produced from microorganism ATCC 55702

DOEpatents

Dees, H. Craig

1998-01-01

Bacteria which produce large amounts of cellulose-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques.

Method of producing a cellulase-containing cell-free fermentate produced from microorganism ATCC 55702

DOEpatents

Dees, H.C.

1998-05-26

Bacteria which produce large amounts of cellulose-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques. 5 figs.

Genetic diversity of Bacillus sp producers of amylase isolated from the soil.

PubMed

Xavier, A R E O; Lima, E R; Oliveira, A M E; Cardoso, L; Santos, J; Cangussu, C H C; Leite, L N; Quirino, M C L; Júnior, I G C; Oliveira, D A; Xavier, M A S

2017-09-27

The microorganisms are the best source of extracellular enzymes since they allow an economical technology with low-resource consumption compared to animals and plants. The amylases are among the most important enzymes being the genus Bacillus one of the most investigated due to its ability to produce this enzyme. The objective of this study was to isolate and analyze the genetic diversity among bacteria of the genus Bacillus sp producer of amylase originated from the soil. To this end, soil samples were collected and submitted to the condition of extreme temperature. The serial dilution procedure followed by seeding on solid medium containing starch was used for isolation of strains that produce amylase. The microorganisms isolated were subjected to standard morphological methods for presumptive identification of the genus Bacillus. The PCR assay with the universal genetic marker 16S rDNA was used for confirmation of bacterial strain. All the 10 isolates presumptively identified as bacteria amplified a fragment of 370 bp corresponding to the 16S rDNA gene. The enzymatic activity was expressed as an enzymatic index (EI), after 24 h of incubation. All isolate producers of amylase exhibited EI ≥ 2.0. The determination of the genetic profile and the clonal relationship among the isolates were performed by the method of ERIC-PCR polymorphism. The isolates of Bacillus spp were divided into 2 groups (I and II). Through this method, the discriminatory capacity of this analysis of polymorphisms was verified in differing producer strains from those not producing amylase.

Iron management and production of electricity by microorganisms.

PubMed

Folgosa, Filipe; Tavares, Pedro; Pereira, Alice S

2015-10-01

The increasing dependency on fossil fuels has driven researchers to seek for alternative energy sources. Renewable energy sources such as sunlight, wind, or water are the most common. However, since the 1990s, other sources for energy production have been studied. The use of microorganisms such as bacteria or archaea to produce energy is currently in great progress. These present several advantages even when compared with other renewable energy sources. Besides the energy production, they are also involved in bioremediation such as the removal of heavy metal contaminants from soils or wastewaters. Several research groups have demonstrated that these organisms are able to interact with electrodes via heme and non-heme iron proteins. Therefore, the role of iron as well as iron metabolism in these species must be of enormous relevance. Recently, the influence of cellular iron regulation by Fur in the Geobacter sulfurreducens growth and ability to produce energy was demonstrated. In this review, we aim to briefly describe the most relevant proteins involved in the iron metabolism of bacteria and archaea and relate them and their biological function with the ability of selected organisms to produce energy.

Biochemical mutagens affect the preservation of fungi and biodiversity estimations.

PubMed

Paterson, R Russell M; Lima, Nelson

2013-01-01

Many fungi have significant industrial applications or biosafety concerns and maintaining the original characteristics is essential. The preserved fungi have to represent the situation in nature for posterity, biodiversity estimations, and taxonomic research. However, spontaneous fungal mutations and secondary metabolites affecting producing fungi are well known. There is increasing interest in the preservation of microbes in Biological Resource Centers (BRC) to ensure that the organisms remain viable and stable genetically. It would be anathema if they contacted mutagens routinely. However, for the purpose of this discussion, there are three potential sources of biochemical mutagens when obtaining individual fungi from the environment: (a) mixtures of microorganisms are plated routinely onto growth media containing mutagenic antibiotics to control overgrowth by contaminants, (b) the microbial mixtures may contain microorganisms capable of producing mutagenic secondary metabolites, and (c) target fungi for isolation may produce "self" mutagens in pure culture. The probability that these compounds could interact with fungi undermines confidence in the preservation process and the potential effects of these biochemical mutagens are considered for the first time on strains held in BRC in this review.

Biocidal Defeat Agents Produced by Silver-Iodine Nanoenergetic Gas Generators

NASA Astrophysics Data System (ADS)

Davila, Ivan

Nanostructured aluminum (Al), iodine pentoxide (I2O5) nano-rods, and silver oxide (Ag2O) nanoparticles, (Al-I2O5-Ag 2O) were used to compose the ternary thermite composition that serves as a Nanoenergetic Gas Generator (NGG). This composition produces biocidal gases giving the mixture the ability to destroy highly pathogenic microorganisms or bacteria. The dissemination of the biocidal gas in combustion chamber was observed using a high-speed camera. The testing of NGG combustion process against the living Escherichia coli (E.coli) K-12 strain cells, that were cultivated/placed on the sample/chamber surfaces, demonstrated that iodine and silver atoms clouds were deposited to the bacteria surface. The 10/75/15 wt % of I2O5/Ag2O/Al composition demonstrated the best performance for destroying of E.coli with efficiency over 99 %. The results of the experiments showed that gaseous silver and iodine generated from NGG combustion produces a strong biocidal environment that has a great potential to neutralize highly pathogenic microorganisms and bacteria.

Plant growth promotion rhizobacteria in onion production.

PubMed

Colo, Josip; Hajnal-Jafari, Timea I; Durić, Simonida; Stamenov, Dragana; Hamidović, Saud

2014-01-01

The aim of the research was to examine the effect of rhizospheric bacteria Azotobacter chroococcum, Pseudomonas fluorescens (strains 1 and 2) and Bacillus subtilis on the growth and yield of onion and on the microorganisms in the rhizosphere of onion. The ability of microorganisms to produce indole-acetic acid (IAA), siderophores and to solubilize tricalcium phosphate (TCP) was also assessed. The experiment was conducted in field conditions, in chernozem type of soil. Bacillus subtilis was the best producer of IAA, whereas Pseudomonas fluorescens strains were better at producing siderophores and solubilizing phosphates. The longest seedling was observed with the application of Azotobacter chroococcum. The height of the plants sixty days after sowing was greater in all the inoculated variants than in the control. The highest onion yield was observed in Bacillus subtilis and Azotobacter chroococcum variants. The total number of bacteria and the number of Azotobacter chroococcum were larger in all the inoculated variants then in the control. The number of fungi decreased in most of the inoculated variants, whereas the number of actinomycetes decreased or remained the same.

Thermophilic xylanases: from bench to bottle.

PubMed

Basit, Abdul; Liu, Junquan; Rahim, Kashif; Jiang, Wei; Lou, Huiqiang

2018-01-17

Lignocellulosic biomass is a valuable raw material. As technology has evolved, industrial interest in new ways to take advantage of this raw material has grown. Biomass is treated with different microbial cells or enzymes under ideal industrial conditions to produce the desired products. Xylanases are the key enzymes that degrade the xylosidic linkages in the xylan backbone of the biomass, and commercial enzymes are categorized into different glycoside hydrolase families. Thermophilic microorganisms are excellent sources of industrially relevant thermostable enzymes that can withstand the harsh conditions of industrial processing. Thermostable xylanases display high-specific activity at elevated temperatures and distinguish themselves in biochemical properties, structures, and modes of action from their mesophilic counterparts. Natural xylanases can be further improved through genetic engineering. Rapid progress with genome editing, writing, and synthetic biological techniques have provided unlimited potential to produce thermophilic xylanases in their natural hosts or cell factories including bacteria, yeasts, and filamentous fungi. This review will discuss the biotechnological potential of xylanases from thermophilic microorganisms and the ways they are being optimized and produced for various industrial applications.

Screening of novel bacteria for the 2,3-butanediol production.

PubMed

Kallbach, Malee; Horn, Sonja; Kuenz, Anja; Prüße, Ulf

2017-02-01

Biotechnologically produced 2,3-butanediol (2,3-BDO) is a potential starting material for industrial bulk chemicals such as butadiene or methyl ethyl ketone which are currently produced from fossil feedstocks. So far, the highest 2,3-BDO concentrations have been obtained with risk group 2 microorganisms. In this study, three risk group 1 microorganisms are presented that are so far unknown for an efficient production of 2,3-BDO. The strains Bacillus atrophaeus NRS-213, Bacillus mojavensis B-14698, and Bacillus vallismortis B-14891 were evaluated regarding their ability to produce high 2,3-BDO concentrations with a broad range of different carbon sources. A maximum 2,3-BDO concentration of 60.4 g/L was reached with the strain B. vallismortis B-14891 with an initial glucose concentration of 200 g/L within 55 h in a batch cultivation. Besides glucose, B. vallismortis B-14891 converts 14 different substrates that can be obtained from residual biomass sources to 2,3-BDO. Therefore B. vallismortis B-14891 is a promising candidate for the large-scale production of 2,3-BDO with low-cost substrates.

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.

Marine Microbiological Enzymes: Studies with Multiple Strategies and Prospects.

PubMed

Wang, Yan; Song, Qinghao; Zhang, Xiao-Hua

2016-09-22

Marine microorganisms produce a series of promising enzymes that have been widely used or are potentially valuable for our daily life. Both classic and newly developed biochemistry technologies have been broadly used to study marine and terrestrial microbiological enzymes. In this brief review, we provide a research update and prospects regarding regulatory mechanisms and related strategies of acyl-homoserine lactones (AHL) lactonase, which is an important but largely unexplored enzyme. We also detail the status and catalytic mechanism of the main types of polysaccharide-degrading enzymes that broadly exist among marine microorganisms but have been poorly explored. In order to facilitate understanding, the regulatory and synthetic biology strategies of terrestrial microorganisms are also mentioned in comparison. We anticipate that this review will provide an outline of multiple strategies for promising marine microbial enzymes and open new avenues for the exploration, engineering and application of various enzymes.

How could haloalkaliphilic microorganisms contribute to biotechnology?

PubMed

Zhao, Baisuo; Yan, Yanchun; Chen, Shulin

2014-11-01

Haloalkaliphiles are microorganisms requiring Na(+) concentrations of at least 0.5 mol·L(-1) and an alkaline pH of 9 for optimal growth. Their unique features enable them to make significant contributions to a wide array of biotechnological applications. Organic compatible solutes produced by haloalkaliphiles, such as ectoine and glycine betaine, are correlated with osmoadaptation and may serve as stabilizers of intracellular proteins, salt antagonists, osmoprotectants, and dermatological moisturizers. Haloalkaliphiles are an important source of secondary metabolites like rhodopsin, polyhydroxyalkanoates, and exopolysaccharides that play essential roles in biogeocycling organic compounds. These microorganisms also can secrete unique exoenzymes, including proteases, amylases, and cellulases, that are highly active and stable in extreme haloalkaline conditions and can be used for the production of laundry detergent. Furthermore, the unique metabolic pathways of haloalkaliphiles can be applied in the biodegradation and (or) biotransformation of a broad range of toxic industrial pollutants and heavy metals, in wastewater treatment, and in the biofuel industry.

The Origin of Invasive Microorganisms Matters for Science, Policy, and Management: The Case of Didymosphenia geminata

PubMed Central

Taylor, Brad W.; Bothwell, Max L.

2014-01-01

The value of distinguishing native from nonnative invasive species has recently been questioned. However, this dichotomy is important for understanding whether a species’ successful dominance is caused by introductions, changing environmental conditions that facilitate an existing population, or both processes. We highlight the importance of knowing the origin of hard-to-detect invasive microorganisms for scientific research, management, and policy using a case study of recent algal blooms of the stalk-producing diatom Didymosphenia geminata. Nuisance blooms have been reported in rivers worldwide and have been hastily attributed to introductions. However, evidence indicates that blooms are probably not caused by introductions but, rather, by environmental conditions that promote excessive stalk production by this historically rare species. Effective responses to invasive microorganisms depend on knowing whether their proliferation is caused by being nonnative or is the result of changing environmental conditions that promote invasive characteristics of native species. PMID:26955071

Effects of Rhamnolipid and Microbial Inoculants on the Vermicomposting of Green Waste with Eisenia fetida.

PubMed

Gong, Xiaoqiang; Wei, Le; Yu, Xin; Li, Suyan; Sun, Xiangyang; Wang, Xinyu

2017-01-01

The effects of adding the biosurfactant rhamnolipid, the lignolytic and cellulolytic fungus Phanerochete chrysosporium, and the free-living nitrogen-fixing bacterium Azotobacter chrococcum on vermicomposting of green waste with Eisenia fetida was investigated. The addition of rhamnolipid and/or either microorganism alone or in all combinations significantly increased E. fetida growth rate, the number of E. fetida juveniles and cocoons, the population densities of cellulolytic fungi and Azotobacter bacteria, and cellulase and urease activities in the vermicomposts. The quality of the final vermicompost (in terms of electrical conductivity, nutrient content, C/N ratio, humic acid content, lignin and cellulose contents, and phytotoxicity to germinating seeds) was enhanced by addition of rhamnolipid and/or microorganisms. The physical characteristics of vermicomposts produced with rhamnolipid and/or microorganisms were acceptable for agricultural application. The best quality vermicompost was obtained with the combined addition of P. chrysosporium, A. chrococcum, and rhamnolipid.

Effects of Rhamnolipid and Microbial Inoculants on the Vermicomposting of Green Waste with Eisenia fetida

PubMed Central

Yu, Xin; Li, Suyan; Sun, Xiangyang; Wang, Xinyu

2017-01-01

The effects of adding the biosurfactant rhamnolipid, the lignolytic and cellulolytic fungus Phanerochete chrysosporium, and the free-living nitrogen-fixing bacterium Azotobacter chrococcum on vermicomposting of green waste with Eisenia fetida was investigated. The addition of rhamnolipid and/or either microorganism alone or in all combinations significantly increased E. fetida growth rate, the number of E. fetida juveniles and cocoons, the population densities of cellulolytic fungi and Azotobacter bacteria, and cellulase and urease activities in the vermicomposts. The quality of the final vermicompost (in terms of electrical conductivity, nutrient content, C/N ratio, humic acid content, lignin and cellulose contents, and phytotoxicity to germinating seeds) was enhanced by addition of rhamnolipid and/or microorganisms. The physical characteristics of vermicomposts produced with rhamnolipid and/or microorganisms were acceptable for agricultural application. The best quality vermicompost was obtained with the combined addition of P. chrysosporium, A. chrococcum, and rhamnolipid. PMID:28122059

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

Increasing fatty acid production in E. coli by simulating the lipid accumulation of oleaginous microorganisms.

PubMed

Meng, Xin; Yang, Jianming; Cao, Yujin; Li, Liangzhi; Jiang, Xinglin; Xu, Xin; Liu, Wei; Xian, Mo; Zhang, Yingwei

2011-08-01

Unlike many oleaginous microorganisms, E. coli only maintains a small amount of natural lipids in cells, impeding its utility to overproduce fatty acids. In this study, acetyl-CoA carboxylase (ACC) from Acinetobacter calcoaceticus was expressed in E. coli to redirect the carbon flux to the generation of malonyl-CoA, which resulted in a threefold increase in intracellular lipids. Moreover, providing a high level of NADPH by overexpressing malic enzyme and adding malate to the culture medium resulted in a fourfold increase in intracellular lipids (about 197.74 mg/g). Co-expression of ACC and malic enzyme resulted in 284.56 mg/g intracellular lipids, a 5.6-fold increase compared to the wild-type strain. This study provides some attractive strategies for increasing lipid production in E. coli by simulating the lipid accumulation of oleaginous microorganisms, which could aid the development of a prokaryotic fatty acid producer.

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. Copyright © 2014 Choi et al.

Diversity and impact of prokaryotic toxins on aquatic environments: a review.

PubMed

Valério, Elisabete; Chaves, Sandra; Tenreiro, Rogério

2010-10-01

Microorganisms are ubiquitous in all habitats and are recognized by their metabolic versatility and ability to produce many bioactive compounds, including toxins. Some of the most common toxins present in water are produced by several cyanobacterial species. As a result, their blooms create major threats to animal and human health, tourism, recreation and aquaculture. Quite a few cyanobacterial toxins have been described, including hepatotoxins, neurotoxins, cytotoxins and dermatotoxins. These toxins are secondary metabolites, presenting a vast diversity of structures and variants. Most of cyanobacterial secondary metabolites are peptides or have peptidic substructures and are assumed to be synthesized by non-ribosomal peptide synthesis (NRPS), involving peptide synthetases, or NRPS/PKS, involving peptide synthetases and polyketide synthases hybrid pathways. Besides cyanobacteria, other bacteria associated with aquatic environments are recognized as significant toxin producers, representing important issues in food safety, public health, and human and animal well being. Vibrio species are one of the most representative groups of aquatic toxin producers, commonly associated with seafood-born infections. Some enterotoxins and hemolysins have been identified as fundamental for V. cholerae and V. vulnificus pathogenesis, but there is evidence for the existence of other potential toxins. Campylobacter spp. and Escherichia coli are also water contaminants and are able to produce important toxins after infecting their hosts. Other bacteria associated with aquatic environments are emerging as toxin producers, namely Legionella pneumophila and Aeromonas hydrophila, described as responsible for the synthesis of several exotoxins, enterotoxins and cytotoxins. Furthermore, several Clostridium species can produce potent neurotoxins. Although not considered aquatic microorganisms, they are ubiquitous in the environment and can easily contaminate drinking and irrigation water. Clostridium members are also spore-forming bacteria and can persist in hostile environmental conditions for long periods of time, contributing to their hazard grade. Similarly, Pseudomonas species are widespread in the environment. Since P. aeruginosa is an emergent opportunistic pathogen, its toxins may represent new hazards for humans and animals. This review presents an overview of the diversity of toxins produced by prokaryotic microorganisms associated with aquatic habitats and their impact on environment, life and health of humans and other animals. Moreover, important issues like the availability of these toxins in the environment, contamination sources and pathways, genes involved in their biosynthesis and molecular mechanisms of some representative toxins are also discussed.

Diversity and Impact of Prokaryotic Toxins on Aquatic Environments: A Review

PubMed Central

Valério, Elisabete; Chaves, Sandra; Tenreiro, Rogério

2010-01-01

Microorganisms are ubiquitous in all habitats and are recognized by their metabolic versatility and ability to produce many bioactive compounds, including toxins. Some of the most common toxins present in water are produced by several cyanobacterial species. As a result, their blooms create major threats to animal and human health, tourism, recreation and aquaculture. Quite a few cyanobacterial toxins have been described, including hepatotoxins, neurotoxins, cytotoxins and dermatotoxins. These toxins are secondary metabolites, presenting a vast diversity of structures and variants. Most of cyanobacterial secondary metabolites are peptides or have peptidic substructures and are assumed to be synthesized by non-ribosomal peptide synthesis (NRPS), involving peptide synthetases, or NRPS/PKS, involving peptide synthetases and polyketide synthases hybrid pathways. Besides cyanobacteria, other bacteria associated with aquatic environments are recognized as significant toxin producers, representing important issues in food safety, public health, and human and animal well being. Vibrio species are one of the most representative groups of aquatic toxin producers, commonly associated with seafood-born infections. Some enterotoxins and hemolysins have been identified as fundamental for V. cholerae and V. vulnificus pathogenesis, but there is evidence for the existence of other potential toxins. Campylobacter spp. and Escherichia coli are also water contaminants and are able to produce important toxins after infecting their hosts. Other bacteria associated with aquatic environments are emerging as toxin producers, namely Legionella pneumophila and Aeromonas hydrophila, described as responsible for the synthesis of several exotoxins, enterotoxins and cytotoxins. Furthermore, several Clostridium species can produce potent neurotoxins. Although not considered aquatic microorganisms, they are ubiquitous in the environment and can easily contaminate drinking and irrigation water. Clostridium members are also spore-forming bacteria and can persist in hostile environmental conditions for long periods of time, contributing to their hazard grade. Similarly, Pseudomonas species are widespread in the environment. Since P. aeruginosa is an emergent opportunistic pathogen, its toxins may represent new hazards for humans and animals. This review presents an overview of the diversity of toxins produced by prokaryotic microorganisms associated with aquatic habitats and their impact on environment, life and health of humans and other animals. Moreover, important issues like the availability of these toxins in the environment, contamination sources and pathways, genes involved in their biosynthesis and molecular mechanisms of some representative toxins are also discussed. PMID:22069558

Production of bulk chemicals via novel metabolic pathways in microorganisms.

PubMed

Shin, Jae Ho; Kim, Hyun Uk; Kim, Dong In; Lee, Sang Yup

2013-11-01

Metabolic engineering has been playing important roles in developing high performance microorganisms capable of producing various chemicals and materials from renewable biomass in a sustainable manner. Synthetic and systems biology are also contributing significantly to the creation of novel pathways and the whole cell-wide optimization of metabolic performance, respectively. In order to expand the spectrum of chemicals that can be produced biotechnologically, it is necessary to broaden the metabolic capacities of microorganisms. Expanding the metabolic pathways for biosynthesizing the target chemicals requires not only the enumeration of a series of known enzymes, but also the identification of biochemical gaps whose corresponding enzymes might not actually exist in nature; this issue is the focus of this paper. First, pathway prediction tools, effectively combining reactions that lead to the production of a target chemical, are analyzed in terms of logics representing chemical information, and designing and ranking the proposed metabolic pathways. Then, several approaches for potentially filling in the gaps of the novel metabolic pathway are suggested along with relevant examples, including the use of promiscuous enzymes that flexibly utilize different substrates, design of novel enzymes for non-natural reactions, and exploration of hypothetical proteins. Finally, strain optimization by systems metabolic engineering in the context of novel metabolic pathways constructed is briefly described. It is hoped that this review paper will provide logical ways of efficiently utilizing 'big' biological data to design and develop novel metabolic pathways for the production of various bulk chemicals that are currently produced from fossil resources. Copyright © 2012 Elsevier Inc. All rights reserved.

Broad spectrum antibiotic compounds and use thereof

DOEpatents

Koglin, Alexander; Strieker, Matthias

2016-07-05

The discovery of a non-ribosomal peptide synthetase (NRPS) gene cluster in the genome of Clostridium thermocellum that produces a secondary metabolite that is assembled outside of the host membrane is described. Also described is the identification of homologous NRPS gene clusters from several additional microorganisms. The secondary metabolites produced by the NRPS gene clusters exhibit broad spectrum antibiotic activity. Thus, antibiotic compounds produced by the NRPS gene clusters, and analogs thereof, their use for inhibiting bacterial growth, and methods of making the antibiotic compounds are described.

WASTE STABILIZATION FUNDAMENTALS FOR BIOREACTOR LANDFILLS

EPA Science Inventory

Waste stabilization is the process where putrescible waste is biodegraded by microorganisms resulting in an end-product being a relatively inert substrate (e.g., like compost). When exposed to moisture, biologically stabilized waste should not produce substantial quantitie...

TSCA Section 5(a)(3)(C) Determination for Microbial Commercial Activity Notice (MCAN) J-16-0036 -- 0041

EPA Pesticide Factsheets

This document describes EPA's Microbial Commercial Activity Notice (MCAN) review determination under amended TSCA for J-16-0036 -- J-16-0041, biofuel producing modified microorganisms, with chromosomally-borne modifications.

In-Situ Anaerobic Biosurfactant Production Process For Remediation Of DNAPL Contamination In Subsurface Aquifers

NASA Astrophysics Data System (ADS)

Albino, J. D.; Nambi, I. M.

2009-12-01

Microbial Enhanced Oil Recovery (MEOR) and remediation of aquifers contaminated with hydrophobic contaminants require insitu production of biosurfactants for mobilization of entrapped hydrophobic liquids. Most of the biosurfactant producing microorganisms produce them under aerobic condition and hence surfactant production is limited in subsurface condition due to lack of oxygen. Currently bioremediation involves expensive air sparging or excavation followed by exsitu biodegradation. Use of microorganisms which can produce biosurfactants under anaerobic conditions can cost effectively expedite the process of insitu bioremediation or mobilization. In this work, the feasibility of anaerobic biosurfactant production in three mixed anaerobic cultures prepared from groundwater and soil contaminated with chlorinated compounds and municipal sewage sludge was investigated. The cultures were previously enriched under complete anaerobic conditions in the presence of Tetrachloroethylene (PCE) for more than a year before they were studied for biosurfactant production. Biosurfactant production under anaerobic conditions was simulated using two methods: i) induction of starvation in the microbial cultures and ii) addition of complex fermentable substrates. Positive result for biosurfactant production was not observed when the cultures were induced with starvation by adding PCE as blobs which served as the only terminal electron acceptor. However, slight reduction in interfacial tension was noticed which was caused by the adherence of microbes to water-PCE interface. Biosurfactant production was observed in all the three cultures when they were fed with complex fermentable substrates and surface tension of the liquid medium was lowered below 35 mN/m. Among the fermentable substrates tested, vegetable oil yielded highest amount of biosurfactant in all the cultures. Complete biodegradation of PCE to ethylene at a faster rate was also observed when vegetable oil was amended to the microbial cultures. The microorganisms responsible for biosurfactant production was isolated and identified as Pseudomonas Sp (designated as Pseudomonas Sp ANBIOSURF-1, Gene bank no: FJ930079), Pseudomonas stutzeri (MTCC 10033), Pseudomonas Sp (MTCC 10032) from groundwater, soil and municipal sewage sludge enrichments respectively. This study confirms that biosurfactants can be produced under anaerobic conditions and also in sufficient quantities. The cultures were also able to cometabolically degrade PCE to Ethylene. The isolated microorganisms can be used for remediation of DNAPL contaminated sites by in-situ biosurfactant production.

Bacterial community analysis of an industrial wastewater treatment plant in Colombia with screening for lipid-degrading microorganisms.

PubMed

Silva-Bedoya, Lina Marcela; Sánchez-Pinzón, María Solange; Cadavid-Restrepo, Gloria Ester; Moreno-Herrera, Claudia Ximena

2016-11-01

The operation of wastewater treatment technologies depends on a combination of physical, chemical and biological factors. Microorganisms present in wastewater treatment plants play essential roles in the degradation and removal of organic waste and xenobiotic pollutants. Several microorganisms have been used in complementary treatments to process effluents rich in fats and oils. Microbial lipases have received significant industrial attention because of their stability, broad substrate specificity, high yields, and regular supply, as well as the fact that the microorganisms producing them grow rapidly on inexpensive media. In Colombia, bacterial community studies have focused on populations of cultivable nitrifying, heterotrophic and nitrogen-fixing bacteria present in constructed wetlands. In this study, culture-dependent methods, culture-independent methods (TTGE, RISA) and enzymatic methods were used to estimate bacterial diversity, to monitor temporal and spatial changes in bacterial communities, and to screen microorganisms that presented lipolytic activity. The dominant microorganisms in the Wastewater Treatment Plant (WWTP) examined in this study belonged to the phyla Firmicutes, Proteobacteria and Bacteroidetes. The enzymatic studies performed indicated that five bacterial isolates and three fungal isolates possessed the ability to degrade lipids; additionally, the Serratia, Kosakonia and Mucor genera presented lipase-mediated transesterification activity. The implications of these findings in regard to possible applications are discussed later in this paper. Our results indicate that there is a wide diversity of aerobic Gram-negative bacteria inhabiting the different sections of the WWTP, which could indicate its ecological condition, functioning and general efficiency. Copyright © 2016 Elsevier GmbH. All rights reserved.

Ice Recrystallization Inhibiting Polymers Enable Glycerol-Free Cryopreservation of Micro-organisms.

PubMed

Hasan, Muhammad; Fayter, Alice E R; Gibson, Matthew I

2018-06-22

All modern molecular biology and microbiology is underpinned not only by the tools to handle and manipulate microorganisms, but also those to store, bank and transport them. Glycerol is the current gold-standard cryoprotectant but it is intrinsically toxic to most micro-organisms: only a fraction of cells survive freezing and the presence of glycerol can impact down-stream applications and assays. Extremophile organisms survive repeated freeze/thaw cycles by producing antifreeze proteins which are potent ice recrystallization inhibitors. Here we introduce a new concept for the storage/transport of micro-organisms by using ice recrystallization inhibiting poly(vinyl alcohol) in tandem with poly(ethylene glycol). This cryopreserving formulation is shown to result in a 4-fold increase in E. coli yield post-thaw, compared to glycerol, utilizing lower concentrations, with successful cryopreservation at just 1.1 weight percent of additive. The mechanism of protection is demonstrated to be linked to inhibiting ice recrystallization (by comparison to a recombinant antifreeze protein) but also to the significantly lower toxicity of the polymers compared to glycerol. Optimized formulations are presented and shown to be broadly applicable to the cryopreservation of a panel of Gram negative, Gram positive and Mycobacteria strains. This represents a step-change in how micro-organisms will be stored by the design of new macromolecular ice growth inhibitors; it should enable a transition from traditional solvent-based to macromolecular microbiology storage methods.

Microbiological agents as health risks in indoor air.

PubMed Central

Burrell, R

1991-01-01

Ambient air may be contaminated with or carry significant levels of a variety of potentially harmful microorganisms. There are three major sources of such microbes: a) those arising from microbial decomposition of various substrates associated with particular occupations (e.g., "moldy" hay leading to hypersensitivity pneumonitis), b) those associated with certain types of environments (e.g., Legionnaires' bacteria in water supplies), and c) those stemming from infective individuals harboring a particular pathogen (e.g., tuberculosis). This presentation deals primarily with important microorganisms from occupational and environmental sources and clearly differentiates from case to case transmission via droplet nuclei infection. Microorganisms that are uniformly injurious are differentiated from those that are more opportunistic (i.e., those that cause problems only in people with preexisting debilities). Such microorganisms are categorized according to whether they are allergenic, infectious, or capable of inducing toxic or inflammatory reactions when inhaled. Representative examples from each of these categories, which include bacteria, fungi, rickettsia, and amoebae, are discussed. The conditions responsible for the entrance of significant numbers of these microbes into the air, the mechanisms by which they produce injury, and the methods of prevention are also considered. With attention given to some of the basic sources and requirements for such microorganisms to reproduce and enter the ambient air environment, it is a relatively simple matter to prevent the occurrence of health problems. PMID:1669959

Assessment of metabolic diversity within the intestinal microbiota from healthy humans using combined molecular and cultural approaches.

PubMed

Chassard, Christophe; Scott, Karen P; Marquet, Perrine; Martin, Jennifer C; Del'homme, Christophe; Dapoigny, Michel; Flint, Harry J; Bernalier-Donadille, Annick

2008-12-01

The human gut harbours a wide range of bacterial communities that play key roles in supplying nutrients and energy to the host through anaerobic fermentation of dietary components and host secretions. This fermentative process involves different functional groups of microorganisms linked in a trophic chain. Although the diversity of the intestinal microbiota has been studied extensively using molecular techniques, the functional aspects of this biodiversity remain mostly unexplored. The aim of the present work was to enumerate the principal metabolic groups of microorganisms involved in the fermentative process in the gut of healthy humans. These functional groups of microorganisms were quantified by a cultural approach, while the taxonomic composition of the microbiota was assessed by in situ hybridization on the same faecal samples. The functional groups of microorganisms that predominated in the gut were the polysaccharide-degrading populations involved in the breakdown of the most readily available exogenous and endogenous substrates and the predominant butyrate-producing species. Most of the functional groups of microorganisms studied appeared to be present at rather similar levels in all healthy volunteers, suggesting that optimal numbers of these various bacterial groups are crucial for efficient gut fermentation, as well as for host nutrition and health. Significant interindividual differences were, however, confirmed with respect to the numbers of methanogenic archaea, filter paper-degrading and acetogenic bacteria and the products formed by lactate-utilizing bacteria.

New Insights about Antibiotic Production by Pseudomonas aeruginosa: A Gene Expression Analysis

PubMed Central

Gionco, Bárbara; Tavares, Eliandro R.; de Oliveira, Admilton G.; Yamada-Ogatta, Sueli F.; do Carmo, Anderson O.; Pereira, Ulisses de Pádua; Chideroli, Roberta T.; Simionato, Ane S.; Navarro, Miguel O. P.; Chryssafidis, Andreas L.; Andrade, Galdino

2017-01-01

The bacterial resistance for antibiotics is one of the most important problems in public health and only a small number of new products are in development. Antagonistic microorganisms from soil are a promising source of new candidate molecules. Products of secondary metabolism confer adaptive advantages for their producer, in the competition for nutrients in the microbial community. The biosynthesis process of compounds with antibiotic activity is the key to optimize their production and the transcriptomic study of microorganisms is of great benefit for the discovery of these metabolic pathways. Pseudomonas aeruginosa LV strain growing in the presence of copper chloride produces a bioactive organometallic compound, which has a potent antimicrobial activity against various microorganisms. The objective of this study was to verify overexpressed genes and evaluate their relation to the organometallic biosynthesis in this microorganism. P. aeruginosa LV strain was cultured in presence and absence of copper chloride. Two methods were used for transcriptomic analysis, genome reference-guided assembly and de novo assembly. The genome referenced analysis identified nine upregulated genes when bacteria were exposed to copper chloride, while the De Novo Assembly identified 12 upregulated genes. Nineteen genes can be related to an increased microbial metabolism for the extrusion process of exceeding intracellular copper. Two important genes are related to the biosynthesis of phenazine and tetrapyrroles compounds, which can be involved in the bioremediation of intracellular copper and we suggesting that may involve in the biosynthesis of the organometallic compound. Additional studies are being carried out to further prove the function of the described genes and relate them to the biosynthetic pathway of the organometallic compound. PMID:28966922

Identification of microorganisms associated with corrosion of offshore oil production systems

NASA Astrophysics Data System (ADS)

Sørensen, Ketil; Grigoryan, Aleksandr; Holmkvist, Lars; Skovhus, Torben; Thomsen, Uffe; Lundgaard, Thomas

2010-05-01

Microbiologically influenced corrosion (MIC) poses a major challenge to oil producers and distributors. The annual cost associated with MIC-related pipeline failures and general maintenance and surveillance of installations amounts to several billion dollar in the oil production sector alone. Hence, large efforts are undertaken by some producers to control and monitor microbial growth in pipelines and other installations, and extensive surveillance programs are carried out in order to detect and quantify potential MIC-promoting microorganisms. Traditionally, efforts to mitigate and survey microbial growth in oil production systems have focused on sulfate-reducing Bacteria (SRB), and microorganisms have usually been enumerated by the culture-dependent MPN (most probable number) -technique. Culture-independent molecular tools yielding much more detailed information about the microbial communities have now been implemented as a reliable tool for routine surveillance of oil production systems in the North Sea. This has resulted in new and hitherto unattainable information regarding the distribution of different microorganisms in hot reservoirs and associated oil production systems. This presentation will provide a review of recent insights regarding thermophilic microbial communities and their implication for steel corrosion in offshore oil production systems. Data collected from solids and biofilms in different corroded pipelines and tubes indicate that in addition to SRB, other groups such as methanogens and sulfate-reducing Archaea (SRA) are also involved in MIC. In the hot parts of the system where the temperature approaches 80 ⁰C, SRA closely related to Archaeoglobus fulgidus outnumber SRB by several orders of magnitude. Methanogens affiliated with the genus Methanothermococcus were shown to completely dominate the microbial community at the metal surface in a sample of highly corroded piping. Thus, the microbial communities associated with MIC appear to be more complex than previously recognized by the industry.

Metatranscriptomic Analyses of Plant Cell Wall Polysaccharide Degradation by Microorganisms in the Cow Rumen

PubMed Central

Dai, Xin; Tian, Yan; Li, Jinting; Su, Xiaoyun; Wang, Xuewei; Zhao, Shengguo; Liu, Li; Luo, Yingfeng; Liu, Di; Zheng, Huajun; Wang, Jiaqi; Dong, Zhiyang

2014-01-01

The bovine rumen represents a highly specialized bioreactor where plant cell wall polysaccharides (PCWPs) are efficiently deconstructed via numerous enzymes produced by resident microorganisms. Although a large number of fibrolytic genes from rumen microorganisms have been identified, it remains unclear how they are expressed in a coordinated manner to efficiently degrade PCWPs. In this study, we performed a metatranscriptomic analysis of the rumen microbiomes of adult Holstein cows fed a fiber diet and obtained a total of 1,107,083 high-quality non-rRNA reads with an average length of 483 nucleotides. Transcripts encoding glycoside hydrolases (GHs) and carbohydrate binding modules (CBMs) accounted for ∼1% and ∼0.1% of the total non-rRNAs, respectively. The majority (∼98%) of the putative cellulases belonged to four GH families (i.e., GH5, GH9, GH45, and GH48) and were primarily synthesized by Ruminococcus and Fibrobacter. Notably, transcripts for GH48 cellobiohydrolases were relatively abundant compared to the abundance of transcripts for other cellulases. Two-thirds of the putative hemicellulases were of the GH10, GH11, and GH26 types and were produced by members of the genera Ruminococcus, Prevotella, and Fibrobacter. Most (∼82%) predicted oligosaccharide-degrading enzymes were GH1, GH2, GH3, and GH43 proteins and were from a diverse group of microorganisms. Transcripts for CBM10 and dockerin, key components of the cellulosome, were also relatively abundant. Our results provide metatranscriptomic evidence in support of the notion that members of the genera Ruminococcus, Fibrobacter, and Prevotella are predominant PCWP degraders and point to the significant contribution of GH48 cellobiohydrolases and cellulosome-like structures to efficient PCWP degradation in the cow rumen. PMID:25501482

DENTINE CARIES: ACID-TOLERANT MICROORGANISMS AND ASPECTS ON COLLAGEN DEGRADATION.

PubMed

Lager, Anders Hedenbjörk

2014-01-01

Dental caries is a common disease all over the world, despite the fact that it can be both effectively prevented and treated. It is driven by acids produced by oral microorganisms as a consequence of their metabolism of dietary carbohydrates. Given enough acid challenge, eventually the tooth enamel barrier will be broken down, and the carious lesion will extend into underlying hard tissue, forming a macroscopic cavity in the dentine. In comparison to biofilm on enamel, a dentine carious lesion provides a vastly different environment for the residing microorganisms. The environment influences the types and numbers of microorganisms that can colonize the dentine caries lesion. The overall aims for this thesis are to enumerate and further study microorganisms found in established dentine caries lesions and also to illuminate how host-derived proteolytic enzymes might contribute to this degradation, not only to better understand the caries process in dentine but also to find incitements for new methods to influence the natural progression of caries lesions. In Paper I, the numbers of remaining viable microorganisms after completed excavation using two excavation methods were investigated. Samples of carious dentine tissue were collected before and after excavation and cultivated on different agar media in different atmospheres. Analysis was performed by counting the number of colony-forming units (CFUs). Key findings: The number of remaining microorganisms after excavation was low for both methods, but some microorganisms always remained in the cavity floors even when the cavities were judged as caries free using normal clinical criteria. In Paper II, the acid tolerant microbiota in established dentine caries lesions was investigated. Samples were taken as in Paper I, but on three levels (superficial, center of lesion, floor of lesion after completed excavation). The samples were cultivated in anaerobic conditions on solid pH-selective agar media of different acidity. Key findings: Each investigated lesion harbored a unique microbiota in terms of both species composition and numbers of microorganisms. This indicates that various combinations of aciduric microorganisms can colonize, survive in and probably also propagate dentine carious lesions. We also found that solid pH-selective agars can be used successfully to select acid-tolerant microorganisms in caries lesions. This would preserve their phenotypic traits for further study. In Paper III, the relation between salivary levels of matrix metalloproteinase-8 (MMP-8), salivary levels of tissue inhibitor of MMP (TIMP-1), and the presence of manifest caries lesions in a large number of subjects was investigated. Saliva samples were collected and analyzed for concentrations of MMP-8, TIMP-1 and total protein using immunofluorometric assays, enzyme linked immunosorbent assays and Bradford assays, respectively. Key findings: Subjects with manifest caries lesions had significantly elevated levels of salivary MMP-8 compared to subjects without caries lesions. TIMP-1 was not significant in any case. In Paper IV, a new method for generating bioactive demineralized dentine matrix substrate (DDM) was developed using a dialysis system and two different demineralization approaches (acetic acid or EDTA). The generated DDM was subsequently analyzed for the presence of type 1 collagen, active MMP-8 and hydroxyproline (HYP) levels using SDS-PAGE, ELISA or immunofluorescence assay. Key findings: Both demineralization methods produced a substrate rich in collagen and with preserved MMP-8 activity. This report presents new knowledge on the composition of the acid tolerant dentine caries microbiota from three levels in dentine carious lesions and on the efficacy of operative caries removal on the numbers of viable microorganisms in the caries free cavity using two operative methods. Moreover, the basic mechanisms behind collagen degradation in the dentine caries process are studied from both a clinical and laboratory perspective. The report also provides a reference for further studies on dentine caries microbiology and dentine caries collagen degradation mechanisms, both of which are known only in part.

An in vitro biofilm model to examine the effect of antibiotic ointments on biofilms produced by burn wound bacterial isolates.

PubMed

Hammond, Adrienne A; Miller, Kyle G; Kruczek, Cassandra J; Dertien, Janet; Colmer-Hamood, Jane A; Griswold, John A; Horswill, Alexander R; Hamood, Abdul N

2011-03-01

Topical treatment of burn wounds is essential as reduced blood supply in the burned tissues restricts the effect of systemic antibiotics. On the burn surface, microorganisms exist within a complex structure termed a biofilm, which enhances bacterial resistance to antimicrobial agents significantly. Since bacteria differ in their ability to develop biofilms, the susceptibility of these biofilms to topically applied antibiotics varies, making it essential to identify which topical antibiotics efficiently disrupt or prevent biofilms produced by these pathogens. Yet, a simple in vitro assay to compare the susceptibility of biofilms produced by burn wound isolates to different topical antibiotics has not been reported. Biofilms were developed by inoculating cellulose disks on agar plates with burn wound isolates and incubating for 24h. The biofilms were then covered for 24h with untreated gauze or gauze coated with antibiotic ointment and remaining microorganisms were quantified and visualized microscopically. Mupirocin and triple antibiotic ointments significantly reduced biofilms produced by the Staphylococcus aureus and Pseudomonas aeruginosa burn wound isolates tested, as did gentamicin ointment, with the exception of one P. aeruginosa clinical isolate. The described assay is a practical and reproducible approach to identify topical antibiotics most effective in eliminating biofilms produced by burn wound isolates. Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.

JPRS Report, Science & Technology: Europe.

DTIC Science & Technology

1988-06-06

genetic material. This, in fact, is the familiar and sometimes old way in which cheese, beer, wine, and yogurt have been produced, to mention just a...of microorganisms, associated to enzyme remodeling; - agro-food fermentation : production of lactic bacteria, beer, amino acids; - biological

Stromatolites

ERIC Educational Resources Information Center

Clary, Renee; Wandersee, James

2013-01-01

Stromatolites are the rocklike structures produced by "microbial mats"--communities of microorganisms only a few millimeters thick--as they trap, bind, or precipitate minerals. This article provides activities and assessment ideas to help teachers incorporate stromatolites in their classrooms. It relates the study of stromatolites to the…

Co-Cultivation—A Powerful Emerging Tool for Enhancing the Chemical Diversity of Microorganisms

PubMed Central

Marmann, Andreas; Aly, Amal H.; Lin, Wenhan; Wang, Bingui; Proksch, Peter

2014-01-01

Marine-derived bacteria and fungi are promising sources of novel bioactive compounds that are important for drug discovery programs. However, as encountered in terrestrial microorganisms there is a high rate of redundancy that results in the frequent re-discovery of known compounds. Apparently only a part of the biosynthetic genes that are harbored by fungi and bacteria are transcribed under routine laboratory conditions which involve cultivation of axenic microbial strains. Many biosynthetic genes remain silent and are not expressed in vitro thereby seriously limiting the chemical diversity of microbial compounds that can be obtained through fermentation. In contrast to this, co-cultivation (also called mixed fermentation) of two or more different microorganisms tries to mimic the ecological situation where microorganisms always co-exist within complex microbial communities. The competition or antagonism experienced during co-cultivation is shown to lead to a significantly enhanced production of constitutively present compounds and/or to an accumulation of cryptic compounds that are not detected in axenic cultures of the producing strain. This review highlights the power of co-cultivation for increasing the chemical diversity of bacteria and fungi drawing on published studies from the marine and from the terrestrial habitat alike. PMID:24549204

Reduction of butyrate- and methane-producing microorganisms in patients with Irritable Bowel Syndrome

PubMed Central

Pozuelo, Marta; Panda, Suchita; Santiago, Alba; Mendez, Sara; Accarino, Anna; Santos, Javier; Guarner, Francisco; Azpiroz, Fernando; Manichanh, Chaysavanh

2015-01-01

The pathophysiology of irritable bowel syndrome (IBS) remains unclear. Here we investigated the microbiome of a large cohort of patients to identify specific signatures for IBS subtypes. We examined the microbiome of 113 patients with IBS and 66 healthy controls. A subset of these participants provided two samples one month apart. We analyzed a total of 273 fecal samples, generating more than 20 million 16S rRNA sequences. In patients with IBS, a significantly lower microbial diversity was associated with a lower relative abundance of butyrate-producing bacteria (P = 0.002; q < 0.06), in particular in patients with IBS-D and IBS-M. IBS patients who did not receive any treatment harboured a lower abundance of Methanobacteria compared to healthy controls (P = 0.005; q = 0.05). Furthermore, significant correlations were observed between several bacterial taxa and sensation of flatulence and abdominal pain (P < 0.05). Altogether, our findings showed that IBS-M and IBS-D patients are characterized by a reduction of butyrate producing bacteria, known to improve intestinal barrier function, and a reduction of methane producing microorganisms a major mechanism of hydrogen disposal in the human colon, which could explain excess of abdominal gas in IBS. PMID:26239401

Chemical and biological monitoring of MIOR on the pilot area of Vyngapour oil field, West Sibera, Russia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arinbasarov, M.U.; Murygina, V.P.; Mats, A.A.

1995-12-31

The pilot area of the Vyngapour oil field allotted for MIOR tests contains three injection and three producing wells. These wells were treated in summer 1993 and 1994. Before, during, and after MIOR treatments on the pilot area the chemical compounds of injected and formation waters were studied, as well as the amount and species of microorganisms entering the stratum with the injected water and indigenous bacteria presented in bottomhole zones of the wells. The results of monitoring showed that the bottomhole zone of the injection well already had biocenosis of heterotrophic, hydrocarbon-oxidizing, methanogenic, and sulfate-reducing bacteria, which were besidesmore » permanently introduced into the reservoir during the usual waterflooding. The nutritious composition activated vital functions of all bacterial species presented in the bottomhole zone of the injection well. The formation waters from producing wells showed the increase of the content of nitrate, sulfate, phosphate, and bicarbonate ions by the end of MIOR. The amount of hydrocarbon-oxidizing bacteria in formation waters of producing wells increased by one order. The chemical and biological monitoring revealed the activation of the formation microorganisms, but no transport of food industry waste bacteria through the formation from injection to producing wells was found.« less

Engineering Corynebacterium crenatum to produce higher alcohols for biofuel using hydrolysates of duckweed (Landoltia punctata) as feedstock.

PubMed

Su, Haifeng; Jiang, Juan; Lu, Qiuli; Zhao, Zhao; Xie, Tian; Zhao, Hai; Wang, Maolin

2015-02-07

Early trials have demonstrated great potential for the use of duckweed (family Lemnaceae) as the next generation of energy plants for the production of biofuels. Achieving this technological advance demands research to develop novel bioengineering microorganisms that can ferment duckweed feedstock to produce higher alcohols. In this study, we used relevant genes to transfer five metabolic pathways of isoleucine, leucine and valine from the yeast Saccharomyces cerevisiae into the bioengineered microorganism Corynebacterium crenatum. Experimental results showed that the bioengineered strain was able to produce 1026.61 mg/L of 2-methyl-1-butanol by fermenting glucose, compared to 981.79 mg/L from the acid hydrolysates of duckweed. The highest isobutanol yields achieved were 1264.63 mg/L from glucose and 1154.83 mg/L from duckweed, and the corresponding highest yields of 3-methyl-1-butanol were 748.35 and 684.79 mg/L. Our findings demonstrate the feasibility of using bioengineered C. crenatum as a platform to construct a bacterial strain that is capable of producing higher alcohols. We have also shown the promise of using duckweed as the basis for developing higher alcohols, illustrating that this group of plants represents an ideal fermentation substrate that can be considered the next generation of alternative energy feedstocks.

Using crude glycerol and thin stillage for the production of microbial lipids through the cultivation of Rhodotorula glutinis.

PubMed

Yen, Hong-Wei; Yang, Ya-Chun; Yu, Yi-Huan

2012-10-01

Single cell oils (SCO) produced from oleaginous microorganisms are a potential alternative oil feedstock for biodiesel production. The worldwide production of glycerol, a 10% (w/w) byproduct produced in the transesterfication process of oils converted to biodiesel, is increasing as more biodiesel is being produced. For the purposes of cost reduction, crude glycerol was regarded as a suitable carbon source for the cultivation of Rhodotorula glutinis. In addition to using renewable crude glycerol, waste solution collected from the brewing company (called thin stillage) was adopted as a substitute to replace a costly nitrogen source used in the medium. The results of using mixture of crude glycerol and thin stillage indicated about a 27% increase in total biomass as compared to that of using crude glycerol with a standard medium. Using glycerol instead of glucose as the carbon source could also alter the lipid profile, resulting in an increase in linolenic acid (C18:2) to comprise over 20% of the total lipid. Successfully using renewable crude glycerol and thin stillage for the cultivation of oleaginous microorganisms could greatly enhance the economic competition of biodiesel produced from SCO. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Technological characterization and survival of the exopolysaccharide-producing strain Lactobacillus delbrueckii subsp. lactis 193 and its bile-resistant derivative 193+ in simulated gastric and intestinal juices.

PubMed

Burns, Patricia; Vinderola, Gabriel; Reinheimer, Jorge; Cuesta, Isabel; de Los Reyes-Gavilán, Clara G; Ruas-Madiedo, Patricia

2011-08-01

The capacity of lactic acid bacteria to produce exopolysaccharides (EPS) conferring microorganisms a ropy phenotype could be an interesting feature from a technological point of view. Progressive adaptation to bile salts might render some lactobacilli able to overcome physiological gut barriers but could also modify functional properties of the strain, including the production of EPS. In this work some technological properties and the survival ability in simulated gastrointestinal conditions of Lactobacillus delbrueckii subsp. lactis 193, and Lb. delbrueckii subsp. lactis 193+, a strain with stable bile-resistant phenotype derived thereof, were characterized in milk in order to know whether the acquisition of resistance to bile could modify some characteristics of the microorganism. Both strains were able to grow and acidify milk similarly; however the production of ethanol increased at the expense of the aroma compound acetaldehyde in milk fermented by the strain 193+, with respect to milk fermented by the strain 193. Both microorganisms produced a heteropolysaccharide composed of glucose and galactose, and were able to increase the viscosity of fermented milks. In spite of the higher production yield of EPS by the bile-resistant strain 193+, it displayed a lower ability to increase viscosity than Lb. delbrueckii subsp. lactis 193. Milk increased survival in simulated gastric juice; the presence of bile improved adhesion to the intestinal cell line HT29-MTX in both strains. However, the acquisition of a stable resistance phenotype did not improve survival in simulated gastric and intestinal conditions or the adhesion to the intestinal cell line HT29-MTX. Thus, Lb. delbrueckii subsp. lactis 193 presents suitable technological properties for the manufacture of fermented dairy products; the acquisition of a stable bile-resistant phenotype modified some properties of the microorganism. This suggests that the possible use of bile-resistant derivative strains should be carefully evaluated in each specific application considering the influence that the acquisition of a stable bile-resistant phenotype could have in survival ability in gastric and intestinal conditions and in technological properties.

Detergent composition comprising a cellulase containing cell-free fermentate produced from microorganism ATCC 55702 or mutant thereof

DOEpatents

Dees, H. Craig

1998-01-01

Bacteria which produce large amounts of a cellulase-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques.

Cellulase-containing cell-free fermentate produced from microorganism ATCC 55702

DOEpatents

Dees, H.C.

1997-12-16

Bacteria which produce large amounts of cellulase-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques. 5 figs.

Process for converting cellulosic materials into fuels and chemicals

DOEpatents

Scott, Charles D.; Faison, Brendlyn D.; Davison, Brian H.; Woodward, Jonathan

1994-01-01

A process for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system.

Recent research progress on microbial L-asparaginases.

PubMed

Zuo, Shaohua; Zhang, Tao; Jiang, Bo; Mu, Wanmeng

2015-02-01

L-Asparaginases (EC 3.5.1.1) are enzymes that catalyze the hydrolysis of L-asparagine to L-aspartic acid and found in a variety of organisms from microorganisms to mammals. However, they are mainly expressed and produced by microorganisms. Microbial L-asparaginases have received sustained attention due to their irreplaceable role in the therapy of acute lymphoblastic leukemia and for their inhibition of acrylamide formation during food processing. In this article, we review the application of microbial L-asparaginases in medical treatments and acrylamide mitigation. In addition, we describe in detail recent advances in the existing sources, purification, production, properties, molecular modification, and immobilization of L-asparaginase.

Microbiological Transformations of Radionuclides in the Subsurface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marshall, Matthew J.; Beliaev, Alex S.; Fredrickson, Jim K.

2010-01-04

Microorganisms are ubiquitous in subsurface environments although their populations sizes and metabolic activities can vary considerably depending on energy and nutrient inputs. As a result of their metabolic activities and the chemical properties of their cell surfaces and the exopolymers they produce, microorganisms can directly or indirectly facilitate the biotransformation of radionuclides, thus altering their solubility and overall fate and transport in the environment. Although biosorption to cell surfaces and exopolymers can be an important factor modifying the solubility of some radionuclides under specific conditions, oxidation state is often considered the single most important factor controlling their speciation and, therefore,more » environmental behavior.« less

Extremozymes from Marine Actinobacteria.

PubMed

Suriya, J; Bharathiraja, S; Krishnan, M; Manivasagan, P; Kim, S-K

Marine microorganisms that have the possibility to survive in diverse conditions such as extreme temperature, pH, pressure, and salinity are known as extremophiles. They produce biocatalysts so named as extremozymes that are active and stable at extreme conditions. These enzymes have numerous industrial applications due to its distinct properties. Till now, only a fraction of microorganisms on Earth have been exploited for screening of extremozymes. Novel techniques used for the cultivation and production of extremophiles, as well as cloning and overexpression of their genes in various expression systems, will pave the way to use these enzymes for chemical, food, pharmaceutical, and other industrial applications. © 2016 Elsevier Inc. All rights reserved.

An ignored and potential source of taste and odor (T&O) issues-biofilms in drinking water distribution system (DWDS).

PubMed

Zhou, Xinyan; Zhang, Kejia; Zhang, Tuqiao; Li, Cong; Mao, Xinwei

2017-05-01

It is important for water utilities to provide esthetically acceptable drinking water to the public, because our consumers always initially judge the quality of the tap water by its color, taste, and odor (T&O). Microorganisms in drinking water contribute largely to T&O production and drinking water distribution systems (DWDS) are known to harbor biofilms and microorganisms in bulk water, even in the presence of a disinfectant. These microbes include T&O-causing bacteria, fungi, and algae, which may lead to unwanted effects on the organoleptic quality of distributed water. Importantly, the understanding of types of these microbes and their T&O compound-producing mechanisms is needed to prevent T&O formation during drinking water distribution. Additionally, new disinfection strategies and operation methods of DWDS are also needed for better control of T&O problems in drinking water. This review covers: (1) the microbial species which can produce T&O compounds in DWDS; (2) typical T&O compounds in DWDS and their formation mechanisms by microorganisms; (3) several common factors in DWDS which can influence the growth and T&O generation of microbes; and (4) several strategies to control biofilm and T&O compound formation in DWDS. At the end of this review, recommendations were given based on the conclusion of this review.

Role of secondary metabolites in the interaction between Pseudomonas fluorescens and soil microorganisms under iron-limited conditions.

PubMed

Deveau, Aurélie; Gross, Harald; Palin, Béatrice; Mehnaz, Samina; Schnepf, Max; Leblond, Pierre; Dorrestein, Pieter C; Aigle, Bertrand

2016-08-01

Microorganisms can be versatile in their interactions with each other, being variously beneficial, neutral or antagonistic in their effect. Although this versatility has been observed among many microorganisms and in many environments, little is known regarding the mechanisms leading to these changes in behavior. In the present work, we analyzed the mechanism by which the soil bacterium Pseudomonas fluorescens BBc6R8 shifts from stimulating the growth of the ectomycorrhizal fungus Laccaria bicolor S238N to killing the fungus. We show that among the three secondary metabolites produced by the bacterial strain-the siderophores enantio-pyochelin and pyoverdine, and the biosurfactant viscosin-the siderophores are mainly responsible for the antagonistic activity of the bacterium under iron-limited conditions. While the bacterial strain continues to produce beneficial factors, their effects are overridden by the action of their siderophores. This antagonistic activity of the strain P. fluorescens BBC6R8 in iron-depleted environments is not restricted to its influence on L. bicolor, since it was also seen to inhibit the growth of the actinomycete Streptomyces ambofaciens ATCC23877. We show that the strain P. fluorescens BBc6R8 uses different strategies to acquire iron, depending on certain biotic and abiotic factors. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Biosurfactant-producing microorganism Pseudomonas sp. SB assists the phytoremediation of DDT-contaminated soil by two grass species.

PubMed

Wang, Beibei; Wang, Qingling; Liu, Wuxing; Liu, Xiaoyan; Hou, Jinyu; Teng, Ying; Luo, Yongming; Christie, Peter

2017-09-01

Phytoremediation together with microorganisms may confer the advantages of both phytoremediation and microbial remediation of soils containing organic contaminants. In this system biosurfactants produced by Pseudomonas sp. SB may effectively help to increase the bioavailability of organic pollutants and thereby enhance their microbial degradation in soil. Plants may enhance the rhizosphere environment for microorganisms and thus promote the bioremediation of contaminants. In the present pot experiment study, dichlorodiphenyltrichloroethane (DDT) residues underwent an apparent decline after soil bioremediation compared with the original soil. The removal efficiency of fertilizer + tall fescue, fertilizer + tall fescue + Pseudomonas, fertilizer + perennial ryegrass, and fertilizer + perennial ryegrass + Pseudomonas treatments were 59.4, 65.6, 69.0, and 65.9%, respectively, and were generally higher than that in the fertilizer control (40.3%). Principal coordinates analysis (PCoA) verifies that plant species greatly affected the soil bacterial community irrespective of inoculation with Pseudomonas sp. SB. Furthermore, community composition analysis shows that Proteobacteria, Acidobacteria and Actinobacteria were the three dominant phyla in all groups. In particular, the relative abundance of Pseudomonas for fertilizer + tall fescue + Pseudomonas (0.25%) was significantly greater than fertilizer + tall fescue and this was related to the DDT removal efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bacillus spp. produce antibacterial activities against lactic acid bacteria that contaminate fuel ethanol plants

USDA-ARS?s Scientific Manuscript database

Lactic acid bacteria (LAB) frequently contaminate commercial fuel ethanol fermentations, reducing yields and decreasing profitability of biofuel production. Microorganisms from environmental sources in different geographic regions of Thailand were tested for antibacterial activity against LAB. Fou...

OVERVIEW OF WATER MICROBIOLOGY AS IT RELATES TO PUBLIC HEALTH

EPA Science Inventory

One of the most important aspects of water microbiology is that we acquire numerous diseases from microorganisms found in water. Some of these diseases represent intoxications. One category of intoxication comes from drinking water which contains toxins produced by cyanobacteria ...

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110 Amyloglucosidase derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus... in man or other animals. (c) The enzyme is produced by a process which completely removes the...

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110 Amyloglucosidase derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus... in man or other animals. (c) The enzyme is produced by a process which completely removes the...

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.

Code of Federal Regulations, 2011 CFR

2011-04-01

... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110 Amyloglucosidase derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus... in man or other animals. (c) The enzyme is produced by a process which completely removes the...

21 CFR 173.110 - Amyloglucosidase derived from Rhizopus niveus.

Code of Federal Regulations, 2010 CFR

2010-04-01

... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.110 Amyloglucosidase derived from Rhizopus niveus. Amyloglucosidase enzyme product, consisting of enzyme derived from Rhizopus... in man or other animals. (c) The enzyme is produced by a process which completely removes the...

PERFORMANCE OF OZONE AS A DISINFECTANT FOR COMBINED SEWER OVERFLOW

EPA Science Inventory

Disinfection of combined sewer overflow (CSO) minimizes the amount of disease-causing microorganisms (pathogens) released into receiving waters. Currently, the primary disinfecting agent used in the US for wastewater treatment is chlorine (Cl2); however, Cl2 produces problems in ...

High value added lipids produced by microorganisms: a potential use of sugarcane vinasse.

PubMed

Fernandes, Bruna Soares; Vieira, João Paulo Fernandes; Contesini, Fabiano Jares; Mantelatto, Paulo Eduardo; Zaiat, Marcelo; Pradella, José Geraldo da Cruz

2017-12-01

This review aims to present an innovative concept of high value added lipids produced by heterotrophic microorganisms, bacteria and fungi, using carbon sources, such as sugars, acids and alcohols that could come from sugarcane vinasse, which is the main byproduct from ethanol production that is released in the distillation step. Vinasse is a rich carbon source and low-cost feedstock produced in large amounts from ethanol production. In 2019, the Brazilian Ministry of Agriculture, Livestock and Food Supply estimates that growth of ethanol domestic consumption will be 58.8 billion liters, more than double the amount in 2008. This represents the annual production of more than 588 billion liters of vinasse, which is currently used as a fertilizer in the sugarcane crop, due to its high concentration of minerals, mainly potassium. However, studies indicate some disadvantages such as the generation of Greenhouse Gas emission during vinasse distribution in the crop, as well as the possibility of contaminating the groundwater and soil. Therefore, the development of programs for sustainable use of vinasse is a priority. One profitable alternative is the fermentation of vinasse, followed by an anaerobic digester, in order to obtain biomaterials such as lipids, other byproducts, and methane. Promising high value added lipids, for instance carotenoids and polyunsaturated fatty acids (PUFAS), with a predicted market of millions of US$, could be produced using vinasse as carbon source, to guide an innovative concept for sustainable production. Example of lipids obtained from the fermentation of compounds present in vinasse are vitamin D, which comes from yeast sucrose fermentation and Omega 3, which can be obtained by bacteria and fungi fermentation. Additionally, several other compounds present in vinasse can be used for this purpose, including sucrose, ethanol, lactate, pyruvate, acetate and other carbon sources. Finally, this paper illustrates the potential market and microbial processes, using microorganisms, for lipid production.

Biochemical Properties of Ectoine Hydroxylases from Extremophiles and Their Wider Taxonomic Distribution among Microorganisms

PubMed Central

Pittelkow, Marco; Heider, Johann; Smits, Sander H. J.; Bremer, Erhard

2014-01-01

Ectoine and hydroxyectoine are well-recognized members of the compatible solutes and are widely employed by microorganisms as osmostress protectants. The EctABC enzymes catalyze the synthesis of ectoine from the precursor L-aspartate-β-semialdehyde. A subgroup of the ectoine producers can convert ectoine into 5-hydroxyectoine through a region-selective and stereospecific hydroxylation reaction. This compatible solute possesses stress-protective and function-preserving properties different from those of ectoine. Hydroxylation of ectoine is carried out by the EctD protein, a member of the non-heme-containing iron (II) and 2-oxoglutarate-dependent dioxygenase superfamily. We used the signature enzymes for ectoine (EctC) and hydroxyectoine (EctD) synthesis in database searches to assess the taxonomic distribution of potential ectoine and hydroxyectoine producers. Among 6428 microbial genomes inspected, 440 species are predicted to produce ectoine and of these, 272 are predicted to synthesize hydroxyectoine as well. Ectoine and hydroxyectoine genes are found almost exclusively in Bacteria. The genome context of the ect genes was explored to identify proteins that are functionally associated with the synthesis of ectoines; the specialized aspartokinase Ask_Ect and the regulatory protein EctR. This comprehensive in silico analysis was coupled with the biochemical characterization of ectoine hydroxylases from microorganisms that can colonize habitats with extremes in salinity (Halomonas elongata), pH (Alkalilimnicola ehrlichii, Acidiphilium cryptum), or temperature (Sphingopyxis alaskensis, Paenibacillus lautus) or that produce hydroxyectoine very efficiently over ectoine (Pseudomonas stutzeri). These six ectoine hydroxylases all possess similar kinetic parameters for their substrates but exhibit different temperature stabilities and differ in their tolerance to salts. We also report the crystal structure of the Virgibacillus salexigens EctD protein in its apo-form, thereby revealing that the iron-free structure exists already in a pre-set configuration to incorporate the iron catalyst. Collectively, our work defines the taxonomic distribution and salient biochemical properties of the ectoine hydroxylase protein family and contributes to the understanding of its structure. PMID:24714029

Iron Sulfide Minerals Record Microbe-Mineral Interactions in Anoxic Environments

NASA Astrophysics Data System (ADS)

Picard, A.; Gartman, A.; Cosmidis, J.; Clarke, D. R.; Girguis, P. R.

2017-12-01

The precipitation of most minerals in low-temperature environments on Earth is directly or indirectly influenced by the presence of organic substances and/or microbial biomass. Notably, the influence of microorganisms on the formation of Mn and Fe oxides/oxyhydroxides at the surface of the Earth has been well characterized (Chan et al., 2011; Estes et al., 2017). However, an oxygenated atmosphere is a unique feature of planet Earth. It is therefore critical for the search of life on other planetary bodies to characterize microbe-mineral interactions that form in anoxic conditions. Here we explore the role of microorganisms on the formation of iron sulfide minerals, which form under anoxic conditions. On modern Earth, sulfate-reducing microorganisms (SRM) are the major source of dissolved sulfide in low-temperature sedimentary environments. We experimentally demonstrate that SRM play a role in the nucleation and growth of iron sulfide minerals by acting as organic templates. The physical characteristics of the resulting minerals are different from those formed under abiotic conditions. Moreover, upon forming, iron sulfide minerals become associated with organic carbon, producing a potential organo-mineral signature. We also evaluate how the presence of various organic substances affect the formation of abiotic minerals and how this could produce false biosignatures that could be mistaken as biogenic minerals. Chan, C.S., Fakra, S.C., Emerson, D., Fleming, E.J. and Edwards, K.J. (2011) Lithotrophic iron-oxidizing bacteria produce organic stalks to control mineral growth: implications for biosignature formation. Isme Journal 5, 717-727. Estes, E.R., Andeer, P.F., Nordlund, D., Wankel, S.D. and Hansel, C.M. (2017) Biogenic manganese oxides as reservoirs of organic carbon and proteins in terrestrial and marine environments. Geobiology 15, 158-172.

Comparison of Biogenic Amines and Mycotoxins in Alfalfa and Red Clover Fodder Depending on Additives

PubMed Central

Skladanka, Jiri; Adam, Vojtech; Zitka, Ondrej; Mlejnkova, Veronika; Kalhotka, Libor; Horky, Pavel; Konecna, Klara; Hodulikova, Lucia; Knotova, Daniela; Balabanova, Marie; Slama, Petr; Skarpa, Petr

2017-01-01

In the production of fermented feed, each crop can be contaminated with a variety of microorganisms that may produce natural pollutants. Biogenic amines, mycotoxins, and undesirable organic acids can decrease health feed safety. The aim of this study was to compare the counts of microorganisms, levels of biogenic amines, and the mycotoxins in forage legumes, and also to compare the occurrence of microorganisms and levels of mycotoxins in green fodder and subsequently produced silage and the influence of additives on the content of natural harmful substances in silage. The experimental plot was located in Troubsko and Vatín, in the Czech Republic. Two varieties of Medicago sativa and one variety of Trifolium pratense were compared. Green fodder and subsequently produced silage reaching up to 23% of dry matter were evaluated and prepared using a bio-enzymatic additive and a chemical additive. Green fodder of Medicago sativa was more contaminated by Enterococci than Trifolium pratense fodder. The obvious difference was determined by the quality of silage leachate. The silage prepared from Medicago sativa fodder was more contaminated with butyric acid. Fungi were present in higher counts in the anaerobic environment of green fodder and contaminated it with zearalenone and deoxynivalenol. Lower counts of fungi were found in silage, although the zearalenone content did not change. Lower content of deoxynivalenol was detected in silage, compared with green fodder. Silages treated with a chemical additive were found not to contain butyric acid. Lower ethanol content was determined, and the tendency to reduce the risk of biogenic amines occurrence was evident. The additives proved to have no influence on the content of mycotoxins. PMID:28420109

Discovery of Gene Cluster for Mycosporine-Like Amino Acid Biosynthesis from Actinomycetales Microorganisms and Production of a Novel Mycosporine-Like Amino Acid by Heterologous Expression

PubMed Central

Miyamoto, Kiyoko T.; Komatsu, Mamoru

2014-01-01

Mycosporines and mycosporine-like amino acids (MAAs), including shinorine (mycosporine-glycine-serine) and porphyra-334 (mycosporine-glycine-threonine), are UV-absorbing compounds produced by cyanobacteria, fungi, and marine micro- and macroalgae. These MAAs have the ability to protect these organisms from damage by environmental UV radiation. Although no reports have described the production of MAAs and the corresponding genes involved in MAA biosynthesis from Gram-positive bacteria to date, genome mining of the Gram-positive bacterial database revealed that two microorganisms belonging to the order Actinomycetales, Actinosynnema mirum DSM 43827 and Pseudonocardia sp. strain P1, possess a gene cluster homologous to the biosynthetic gene clusters identified from cyanobacteria. When the two strains were grown in liquid culture, Pseudonocardia sp. accumulated a very small amount of MAA-like compound in a medium-dependent manner, whereas A. mirum did not produce MAAs under any culture conditions, indicating that the biosynthetic gene cluster of A. mirum was in a cryptic state in this microorganism. In order to characterize these biosynthetic gene clusters, each biosynthetic gene cluster was heterologously expressed in an engineered host, Streptomyces avermitilis SUKA22. Since the resultant transformants carrying the entire biosynthetic gene cluster controlled by an alternative promoter produced mainly shinorine, this is the first confirmation of a biosynthetic gene cluster for MAA from Gram-positive bacteria. Furthermore, S. avermitilis SUKA22 transformants carrying the biosynthetic gene cluster for MAA of A. mirum accumulated not only shinorine and porphyra-334 but also a novel MAA. Structure elucidation revealed that the novel MAA is mycosporine-glycine-alanine, which substitutes l-alanine for the l-serine of shinorine. PMID:24907338

Discovery of gene cluster for mycosporine-like amino acid biosynthesis from Actinomycetales microorganisms and production of a novel mycosporine-like amino acid by heterologous expression.

PubMed

Miyamoto, Kiyoko T; Komatsu, Mamoru; Ikeda, Haruo

2014-08-01

Mycosporines and mycosporine-like amino acids (MAAs), including shinorine (mycosporine-glycine-serine) and porphyra-334 (mycosporine-glycine-threonine), are UV-absorbing compounds produced by cyanobacteria, fungi, and marine micro- and macroalgae. These MAAs have the ability to protect these organisms from damage by environmental UV radiation. Although no reports have described the production of MAAs and the corresponding genes involved in MAA biosynthesis from Gram-positive bacteria to date, genome mining of the Gram-positive bacterial database revealed that two microorganisms belonging to the order Actinomycetales, Actinosynnema mirum DSM 43827 and Pseudonocardia sp. strain P1, possess a gene cluster homologous to the biosynthetic gene clusters identified from cyanobacteria. When the two strains were grown in liquid culture, Pseudonocardia sp. accumulated a very small amount of MAA-like compound in a medium-dependent manner, whereas A. mirum did not produce MAAs under any culture conditions, indicating that the biosynthetic gene cluster of A. mirum was in a cryptic state in this microorganism. In order to characterize these biosynthetic gene clusters, each biosynthetic gene cluster was heterologously expressed in an engineered host, Streptomyces avermitilis SUKA22. Since the resultant transformants carrying the entire biosynthetic gene cluster controlled by an alternative promoter produced mainly shinorine, this is the first confirmation of a biosynthetic gene cluster for MAA from Gram-positive bacteria. Furthermore, S. avermitilis SUKA22 transformants carrying the biosynthetic gene cluster for MAA of A. mirum accumulated not only shinorine and porphyra-334 but also a novel MAA. Structure elucidation revealed that the novel MAA is mycosporine-glycine-alanine, which substitutes l-alanine for the l-serine of shinorine. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Comparison of Biogenic Amines and Mycotoxins in Alfalfa and Red Clover Fodder Depending on Additives.

PubMed

Skladanka, Jiri; Adam, Vojtech; Zitka, Ondrej; Mlejnkova, Veronika; Kalhotka, Libor; Horky, Pavel; Konecna, Klara; Hodulikova, Lucia; Knotova, Daniela; Balabanova, Marie; Slama, Petr; Skarpa, Petr

2017-04-14

In the production of fermented feed, each crop can be contaminated with a variety of microorganisms that may produce natural pollutants. Biogenic amines, mycotoxins, and undesirable organic acids can decrease health feed safety. The aim of this study was to compare the counts of microorganisms, levels of biogenic amines, and the mycotoxins in forage legumes, and also to compare the occurrence of microorganisms and levels of mycotoxins in green fodder and subsequently produced silage and the influence of additives on the content of natural harmful substances in silage. The experimental plot was located in Troubsko and Vatín, in the Czech Republic. Two varieties of Medicago sativa and one variety of Trifolium pratense were compared. Green fodder and subsequently produced silage reaching up to 23% of dry matter were evaluated and prepared using a bio-enzymatic additive and a chemical additive. Green fodder of Medicago sativa was more contaminated by Enterococci than Trifolium pratense fodder. The obvious difference was determined by the quality of silage leachate. The silage prepared from Medicago sativa fodder was more contaminated with butyric acid. Fungi were present in higher counts in the anaerobic environment of green fodder and contaminated it with zearalenone and deoxynivalenol. Lower counts of fungi were found in silage, although the zearalenone content did not change. Lower content of deoxynivalenol was detected in silage, compared with green fodder. Silages treated with a chemical additive were found not to contain butyric acid. Lower ethanol content was determined, and the tendency to reduce the risk of biogenic amines occurrence was evident. The additives proved to have no influence on the content of mycotoxins.

Characteristics and adaptability of iron- and sulfur-oxidizing microorganisms used for the recovery of metals from minerals and their concentrates

PubMed Central

Rawlings, Douglas E

2005-01-01

Microorganisms are used in large-scale heap or tank aeration processes for the commercial extraction of a variety of metals from their ores or concentrates. These include copper, cobalt, gold and, in the past, uranium. The metal solubilization processes are considered to be largely chemical with the microorganisms providing the chemicals and the space (exopolysaccharide layer) where the mineral dissolution reactions occur. Temperatures at which these processes are carried out can vary from ambient to 80°C and the types of organisms present depends to a large extent on the process temperature used. Irrespective of the operation temperature, biomining microbes have several characteristics in common. One shared characteristic is their ability to produce the ferric iron and sulfuric acid required to degrade the mineral and facilitate metal recovery. Other characteristics are their ability to grow autotrophically, their acid-tolerance and their inherent metal resistance or ability to acquire metal resistance. Although the microorganisms that drive the process have the above properties in common, biomining microbes usually occur in consortia in which cross-feeding may occur such that a combination of microbes including some with heterotrophic tendencies may contribute to the efficiency of the process. The remarkable adaptability of these organisms is assisted by several of the processes being continuous-flow systems that enable the continual selection of microorganisms that are more efficient at mineral degradation. Adaptability is also assisted by the processes being open and non-sterile thereby permitting new organisms to enter. This openness allows for the possibility of new genes that improve cell fitness to be selected from the horizontal gene pool. Characteristics that biomining microorganisms have in common and examples of their remarkable adaptability are described. PMID:15877814

Characteristics and adaptability of iron- and sulfur-oxidizing microorganisms used for the recovery of metals from minerals and their concentrates.

PubMed

Rawlings, Douglas E

2005-05-06

Microorganisms are used in large-scale heap or tank aeration processes for the commercial extraction of a variety of metals from their ores or concentrates. These include copper, cobalt, gold and, in the past, uranium. The metal solubilization processes are considered to be largely chemical with the microorganisms providing the chemicals and the space (exopolysaccharide layer) where the mineral dissolution reactions occur. Temperatures at which these processes are carried out can vary from ambient to 80 degrees C and the types of organisms present depends to a large extent on the process temperature used. Irrespective of the operation temperature, biomining microbes have several characteristics in common. One shared characteristic is their ability to produce the ferric iron and sulfuric acid required to degrade the mineral and facilitate metal recovery. Other characteristics are their ability to grow autotrophically, their acid-tolerance and their inherent metal resistance or ability to acquire metal resistance. Although the microorganisms that drive the process have the above properties in common, biomining microbes usually occur in consortia in which cross-feeding may occur such that a combination of microbes including some with heterotrophic tendencies may contribute to the efficiency of the process. The remarkable adaptability of these organisms is assisted by several of the processes being continuous-flow systems that enable the continual selection of microorganisms that are more efficient at mineral degradation. Adaptability is also assisted by the processes being open and non-sterile thereby permitting new organisms to enter. This openness allows for the possibility of new genes that improve cell fitness to be selected from the horizontal gene pool. Characteristics that biomining microorganisms have in common and examples of their remarkable adaptability are described.

Halophilic microorganisms in deteriorated historic buildings: insights into their characteristics.

PubMed

Adamiak, Justyna; Otlewska, Anna; Gutarowska, Beata; Pietrzak, Anna

2016-01-01

Historic buildings are constantly being exposed to numerous climatic changes such as damp and rainwater. Water migration into and out of the material's pores can lead to salt precipitation and the so-called efflorescence. The structure of the material may be seriously threatened by salt crystallization. A huge pressure is produced when salt hydrates occupy larger spaces, which leads at the end to cracking, detachment and material loss. Halophilic microorganisms have the ability to adapt to high salinity because of the mechanisms of inorganic salt (KCl or NaCl) accumulation in their cells at concentrations isotonic to the environment, or compatible solutes uptake or synthesis. In this study, we focused our attention on the determination of optimal growth conditions of halophilic microorganisms isolated from historical buildings in terms of salinity, pH and temperature ranges, as well as biochemical properties and antagonistic abilities. Halophilic microorganisms studied in this paper could be categorized as a halotolerant group, as they grow in the absence of NaCl, as well as tolerate higher salt concentrations (Staphylococcus succinus, Virgibacillus halodenitrificans). Halophilic microorganisms have been also observed (Halobacillus styriensis, H. hunanensis, H. naozhouensis, H. litoralis, Marinococcus halophilus and yeast Sterigmatomyces halophilus). With respect to their physiological characteristics, cultivation at a temperature of 25-30°C, pH 6-7, NaCl concentration for halotolerant and halophilic microorganisms, 0-10% and 15-30%, respectively, provides the most convenient conditions. Halophiles described in this study displayed lipolytic, glycolytic and proteolytic activities. Staphylococcus succinus and Marinococcus halophilus showed strong antagonistic potential towards bacteria from the Bacillus genus, while Halobacillus litoralis displayed an inhibiting ability against other halophiles.

Diversity of bacteria producing pigmented colonies in aerosol, snow and soil samples from remote glacial areas (Antarctica, Alps and Andes)

NASA Astrophysics Data System (ADS)

González-Toril, E.; Amils, R.; Delmas, R. J.; Petit, J.-R.; Komárek, J.; Elster, J.

2008-04-01

Four different communities and one culture of pigmented microbial assemblages were obtained by incubation in mineral medium of samples collected from high elevation snow in the Alps (Mt. Blanc area) and the Andes (Nevado Illimani summit, Bolivia), from Antarctic aerosol (French station Dumont d'Urville) and a maritime Antarctic soil (King George Island, South Shetlands, Uruguay Station Artigas). Molecular analysis of more than 200 16S rRNA gene sequences showed that all cultured cells belong to the Bacteria domain. The phylogenetic comparison with the currently available rDNA database allowed the identification of sequences belonging to Proteobacteria (Alpha-, Beta- and Gamma-proteobacteria), Actinobacteria and Bacteroidetes phyla. The Andes snow culture was the richest in bacterial diversity (eight microorganisms identified) and the maritime Antarctic soil the poorest (only one). Snow samples from Col du midi (Alps) and the Andes shared the highest number of identified microorganisms (Agrobacterium, Limnobacter, Aquiflexus and two uncultured Alphaproteobacteria clones). These two sampling sites also shared four sequences with the Antarctic aerosol sample (Limnobacter, Pseudonocardia and an uncultured Alphaproteobacteria clone). The only microorganism identified in the maritime Antarctica soil (Brevundimonas sp.) was also detected in the Antarctic aerosol. The two snow samples from the Alps only shared one common microorganism. Most of the identified microorganisms have been detected previously in cold environments (Dietzia kujamenisi, Pseudonocardia Antarctica, Hydrogenophaga palleronii and Brebundimonas sp.), marine sediments (Aquiflexus balticus, Pseudomonas pseudoalkaligenes, Pseudomonas sp. and one uncultured Alphaproteobacteria), and soils and rocks (Pseudonocardia sp., Agrobactrium sp., Limnobacter sp. and two uncultured Alphaproteobacetria clones). Air current dispersal is the best model to explain the presence of very specific microorganisms, like those used in this work, in very distant environments. In addition these microorganisms have to be resistant to extreme conditions and able to grow in oligotrophic environments. Considering the habitats in which they have been identified, the presence of pigments must be related with their ability to resist high doses of radiation.

Mercury methylation rates of biofilm and plankton microorganisms from a hydroelectric reservoir in French Guiana.

PubMed

Huguet, L; Castelle, S; Schäfer, J; Blanc, G; Maury-Brachet, R; Reynouard, C; Jorand, F

2010-02-15

The Petit-Saut ecosystem is a hydroelectric reservoir covering 365km(2) of flooded tropical forest. This reservoir and the Sinnamary Estuary downstream of the dam are subject to significant mercury methylation. The mercury methylation potential of plankton and biofilm microorganisms/components from different depths in the anoxic reservoir water column and from two different sites along the estuary was assessed. For this, reservoir water and samples of epiphytic biofilms from the trunk of a submerged tree in the anoxic water column and from submerged branches in the estuary were batch-incubated from 1h to 3 months with a nominal 1000ng/L spike of Hg(II) chloride enriched in (199)Hg. Methylation rates were determined for different reservoir and estuarine communities under natural nutrient (reservoir water, estuary freshwater) and artificial nutrient (culture medium) conditions. Methylation rates in reservoir water incubations were the highest with plankton microorganisms sampled at -9.5m depth (0.5%/d) without addition of biofilm components. Mercury methylation rates of incubated biofilm components were strongly enhanced by nutrient addition. The results suggested that plankton microorganisms strongly contribute to the total Hg methylation in the Petit-Saut reservoir and in the Sinnamary Estuary. Moreover, specific methylation efficiencies (%Me(199)Hg(net)/cell) suggested that plankton microorganisms could be more efficient methylating actors than biofilm consortia and that their methylation efficiency may be reduced in the presence of biofilm components. Extrapolation to the reservoir scale of the experimentally determined preliminary methylation efficiencies suggested that plankton microorganisms in the anoxic water column could produce up to 27mol MeHg/year. Taking into account that (i) demethylation probably occurs in the reservoir and (ii) that the presence of biofilm components may limit the methylation efficiency of plankton microorganisms, this result is highly consistent with the annual net MeHg production estimated from mass balances (8.1mol MeHg/year, Muresan et al., 2008a).

Microbial Contamination of Contact Lenses, Lens Care Solutions, and Their Accessories: A Literature Review

PubMed Central

Szczotka-Flynn, Loretta B.; Pearlman, Eric; Ghannoum, Mahmoud

2012-01-01

Purpose A contact lens (CL) can act as a vector for microorganisms to adhere to and transfer to the ocular surface. Commensal microorganisms that uneventfully cohabitate on lid margins and conjunctivae and potential pathogens that are found transiently on the ocular surface can inoculate CLs in vivo. In the presence of reduced tissue resistance, these resident microorganisms or transient pathogens can invade and colonize the cornea or conjunctiva to produce inflammation or infection. Methods The literature was reviewed and used to summarize the findings over the last 30 years on the identification, enumeration, and classification of microorganisms adherent to CLs and their accessories during the course of normal wear and to hypothesize the role that these microorganisms play in CL infection and inflammation. Results Lens handling greatly increases the incidence of lens contamination, and the ocular surface has a tremendous ability to destroy organisms. However, even when removed aseptically from the eye, more than half of lenses are found to harbor microorganisms, almost exclusively bacteria. Coagulase-negative Staphylococci are most commonly cultured from worn lenses; however, approximately 10% of lenses harbor Gram-negative and highly pathogenic species, even in asymptomatic subjects. In storage cases, the incidence of positive microbial bioburden is also typically greater than 50%. All types of care solutions can become contaminated, including up to 30% of preserved products. Conclusions The process of CL-related microbial keratitis and inflammation is thought to be preceded by the presence or transfer or both of microorganisms from the lens to the ocular surface. Thus, this detailed understanding of lens-related bioburden is important in the understanding of factors associated with infectious and inflammatory complications. Promising mechanisms to prevent bacterial colonization on lenses and lens cases are forthcoming, which may decrease the incidence of microbially driven CL complications. PMID:20168237

Scavenging of ice-nucleating microorganisms from the atmosphere by artificial rain events

NASA Astrophysics Data System (ADS)

Hanlon, Regina; Powers, Craig; Failor, Kevin; Vinatzer, Boris; Schmale, David

2015-04-01

Little is known about how microorganisms are scavenged from the atmosphere during rainfall. Microorganisms are abundant and diverse in rain (precipitation) collected near the surface of the earth. Some of these rain-associated microorganisms produce proteins that catalyze the nucleation of ice crystals at significantly warmer temperatures than would normally be required for ice formation, suggesting that they may play important roles in weather, including the onset of precipitation. We conducted a series of field experiments to test the hypothesis that ice-nucleating microorganisms are scavenged from the atmosphere by rainfall. Thirteen artificial rain events were conducted off the side of the Smart Road Bridge in Blacksburg, VA, USA. In each event, sterile water was dispensed over the side of the bridge (simulated rainfall), and recovered in sterile containers following gravitational settling from the side of the bridge to an open fallow agricultural field below (a distance of ~55m from the release site to the collection site). Microbes scavenged from the artificial rain events were cultured on six different types of agar media (R2A, TSA, CA; +/- cycloheximide) and the ice nucleation activity was examined for colonies cultured from the different media types. Mean CFUs scavenged by artificial rain ranged from 83 to 196 CFUs/mL across all six media types. Ice-nucleating microorganisms were recovered from 85% (11/13) of the simulated rain events, and represented about 1% of the total number of colonies assayed from each event. Strikingly, this percentage is nearly identical to the percentage of culturable ice-nucleating microorganisms occurring in about half of the natural rain events studied to date in Blacksburg, Virginia. This work expands our knowledge of the scavenging properties of rain, and suggests that at least some ice nucleators in natural precipitation events may have been stripped from the atmosphere during rainfall, thus negating their potential role in the onset of precipitation.

New exopolysaccharides produced by Aureobasidium pullulans grown on glucosamine.

PubMed

Cescutti, Paola; Pupulin, Raffaella; Delben, Franco; Abbate, Maria; Dentini, Mariella; Sparapano, Lorenzo; Rizzo, Roberto; Crescenzi, Vittorio

2002-07-16

The polysaccharides produced by Aureobasidium pullulans, grown using glucosamine as the carbon source, were investigated by means of methylation analysis, affinity chromatography and NMR spectroscopy. The results indicated that, besides a small amount of pullulan, this micro-organism was capable of producing-in low yields-mixtures of at least two different complex polysaccharides containing mainly mannose and galactose. (1)H NMR spectra of two fractions obtained by lectin affinity chromatography indicated that one polymer was constituted exclusively of mannose residues while the other contained both galactofuranosyl and mannopyranosyl residues.

Influence of Niche-Specific Nutrients on Secondary Metabolism in Vibrionaceae.

PubMed

Giubergia, Sonia; Phippen, Christopher; Gotfredsen, Charlotte H; Nielsen, Kristian Fog; Gram, Lone

2016-07-01

Many factors, such as the substrate and the growth phase, influence biosynthesis of secondary metabolites in microorganisms. Therefore, it is crucial to consider these factors when establishing a bioprospecting strategy. Mimicking the conditions of the natural environment has been suggested as a means of inducing or influencing microbial secondary metabolite production. The purpose of the present study was to determine how the bioactivity of Vibrionaceae was influenced by carbon sources typical of their natural environment. We determined how mannose and chitin, compared to glucose, influenced the antibacterial activity of a collection of Vibrionaceae strains isolated because of their ability to produce antibacterial compounds but that in subsequent screenings seemed to have lost this ability. The numbers of bioactive isolates were 2- and 3.5-fold higher when strains were grown on mannose and chitin, respectively, than on glucose. As secondary metabolites are typically produced during late growth, potential producers were also allowed 1 to 2 days of growth before exposure to the pathogen. This strategy led to a 3-fold increase in the number of bioactive strains on glucose and an 8-fold increase on both chitin and mannose. We selected two bioactive strains belonging to species for which antibacterial activity had not previously been identified. Using ultrahigh-performance liquid chromatography-high-resolution mass spectrometry and bioassay-guided fractionation, we found that the siderophore fluvibactin was responsible for the antibacterial activity of Vibrio furnissii and Vibrio fluvialis These results suggest a role of chitin in the regulation of secondary metabolism in vibrios and demonstrate that considering bacterial ecophysiology during development of screening strategies will facilitate bioprospecting. A challenge in microbial natural product discovery is the elicitation of the biosynthetic gene clusters that are silent when microorganisms are grown under standard laboratory conditions. We hypothesized that, since the clusters are not lost during proliferation in the natural niche of the microorganisms, they must, under such conditions, be functional. Here, we demonstrate that an ecology-based approach in which the producer organism is allowed a temporal advantage and where growth conditions are mimicking the natural niche remarkably increases the number of Vibrionaceae strains producing antibacterial compounds. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Rewriting the Metabolic Blueprint: Advances in Pathway Diversification in Microorganisms

PubMed Central

Hossain, Gazi Sakir; Nadarajan, Saravanan Prabhu; Zhang, Lei; Ng, Tee-Kheang; Foo, Jee Loon; Ling, Hua; Choi, Won Jae; Chang, Matthew Wook

2018-01-01

Living organisms have evolved over millions of years to fine tune their metabolism to create efficient pathways for producing metabolites necessary for their survival. Advancement in the field of synthetic biology has enabled the exploitation of these metabolic pathways for the production of desired compounds by creating microbial cell factories through metabolic engineering, thus providing sustainable routes to obtain value-added chemicals. Following the past success in metabolic engineering, there is increasing interest in diversifying natural metabolic pathways to construct non-natural biosynthesis routes, thereby creating possibilities for producing novel valuable compounds that are non-natural or without elucidated biosynthesis pathways. Thus, the range of chemicals that can be produced by biological systems can be expanded to meet the demands of industries for compounds such as plastic precursors and new antibiotics, most of which can only be obtained through chemical synthesis currently. Herein, we review and discuss novel strategies that have been developed to rewrite natural metabolic blueprints in a bid to broaden the chemical repertoire achievable in microorganisms. This review aims to provide insights on recent approaches taken to open new avenues for achieving biochemical production that are beyond currently available inventions. PMID:29483901

Effect of halotolerant starter microorganisms on chemical characteristics of fermented chum salmon (Oncorhynchus keta) sauce.

PubMed

Yoshikawa, Shuji; Kurihara, Hideyuki; Kawai, Yuji; Yamazaki, Koji; Tanaka, Akira; Nishikiori, Takafumi; Ohta, Tomoki

2010-05-26

Chum salmon sauce mash was inoculated with barley koji (barley steamed and molded with Aspergillus oryzae ) and halotolerant microorganisms (HTMs), Zygosaccharomyces rouxii , Candida versatilis , and Tetragenococcus halophilus , in nine different combinations under non-aseptic conditions similar to the industrial fish sauce production and fermented at 35 +/- 2.5 degrees C for 84 days. The changes in the chemical components, color, and sensory properties during fermentation were investigated. Free amino acid content was increased, and the browning of fish sauce was enhanced by the usage of barley koji during fermentation. The halotolerant yeast (HTY) produced ethanol and repressed the browning by consumption of reducing sugar. Inoculated Z. rouxii in the fish sauce mash produced 2-phenylethanol (2-PE) and 4-hydoxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF), and C. versatilis in the fish sauce mash produced 4-ethylguaiacol (4-EG), known as characteristic flavor compounds in soy sauce, adding soy-sauce-like flavor to the fish sauce. Thus, inoculation of HTMs and barley koji was effective for conferring the soy-sauce-like flavor and increasing free amino acid and ethanol contents in fish sauce product.

Rewriting the Metabolic Blueprint: Advances in Pathway Diversification in Microorganisms.

PubMed

Hossain, Gazi Sakir; Nadarajan, Saravanan Prabhu; Zhang, Lei; Ng, Tee-Kheang; Foo, Jee Loon; Ling, Hua; Choi, Won Jae; Chang, Matthew Wook

2018-01-01

Living organisms have evolved over millions of years to fine tune their metabolism to create efficient pathways for producing metabolites necessary for their survival. Advancement in the field of synthetic biology has enabled the exploitation of these metabolic pathways for the production of desired compounds by creating microbial cell factories through metabolic engineering, thus providing sustainable routes to obtain value-added chemicals. Following the past success in metabolic engineering, there is increasing interest in diversifying natural metabolic pathways to construct non-natural biosynthesis routes, thereby creating possibilities for producing novel valuable compounds that are non-natural or without elucidated biosynthesis pathways. Thus, the range of chemicals that can be produced by biological systems can be expanded to meet the demands of industries for compounds such as plastic precursors and new antibiotics, most of which can only be obtained through chemical synthesis currently. Herein, we review and discuss novel strategies that have been developed to rewrite natural metabolic blueprints in a bid to broaden the chemical repertoire achievable in microorganisms. This review aims to provide insights on recent approaches taken to open new avenues for achieving biochemical production that are beyond currently available inventions.

Thermophilic lignocellulose deconstruction.

PubMed

Blumer-Schuette, Sara E; Brown, Steven D; Sander, Kyle B; Bayer, Edward A; Kataeva, Irina; Zurawski, Jeffrey V; Conway, Jonathan M; Adams, Michael W W; Kelly, Robert M

2014-05-01

Thermophilic microorganisms are attractive candidates for conversion of lignocellulose to biofuels because they produce robust, effective, carbohydrate-degrading enzymes and survive under harsh bioprocessing conditions that reflect their natural biotopes. However, no naturally occurring thermophile is known that can convert plant biomass into a liquid biofuel at rates, yields and titers that meet current bioprocessing and economic targets. Meeting those targets requires either metabolically engineering solventogenic thermophiles with additional biomass-deconstruction enzymes or engineering plant biomass degraders to produce a liquid biofuel. Thermostable enzymes from microorganisms isolated from diverse environments can serve as genetic reservoirs for both efforts. Because of the sheer number of enzymes that are required to hydrolyze plant biomass to fermentable oligosaccharides, the latter strategy appears to be the preferred route and thus has received the most attention to date. Thermophilic plant biomass degraders fall into one of two categories: cellulosomal (i.e. multienzyme complexes) and noncellulosomal (i.e. 'free' enzyme systems). Plant-biomass-deconstructing thermophilic bacteria from the genera Clostridium (cellulosomal) and Caldicellulosiruptor (noncellulosomal), which have potential as metabolic engineering platforms for producing biofuels, are compared and contrasted from a systems biology perspective. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

A review on microbiological decontamination of fresh produce with nonthermal plasma.

PubMed

Pignata, C; D'Angelo, D; Fea, E; Gilli, G

2017-06-01

Food safety is a critical public health issue for consumers and the food industry because microbiological contamination of food causes considerable social and economic burdens on health care. Most foodborne illness comes from animal production, but as of the mid-1990s in the United States and more recently in the European Union, the contribution of fresh produce to foodborne outbreaks has rapidly increased. Recent studies have suggested that sterilization with nonthermal plasma could be a viable alternative to the traditional methods for the decontamination of heat-sensitive materials or food because this technique proves capable of eliminating micro-organisms on surfaces without altering the substrate. In the last 10 years, researchers have used nonthermal plasma in a variety of food inoculated with many bacterial species. All of these experiments were conducted exclusively in a laboratory and, to our knowledge, this technique has not been used in an industrial setting. Thus, the purpose of this review is to understand whether this technology could be used at the industrial level. The latest researches using nonthermal plasma on fresh produce were analysed. These evaluations have focused on the log reduction of micro-organisms and the treatment time. © 2017 The Society for Applied Microbiology.

Processes for producing polyhydroxybutyrate and related polyhydroxyalkanoates in the plastids of higher plants

DOEpatents

Somerville, Christopher R.; Nawrath, Christiane; Poirier, Yves

1997-03-11

The present invention relates to a process for producing poly-D-(-)-3-hydroxybutyric acid (PHB) and related polyhydroxyalkanoates (PHA) in the plastids of plants. The production of PHB is accomplished by genetically transforming plants with modified genes from microorganisms. The genes encode the enzymes required to synthesize PHB from acetyl-CoA or related metabolites and are fused with additional plant sequences for targeting the enzymes to the plastid.

TSCA Environmental Release Application (TERA) for Pseudomonas putida (P. putida)

EPA Pesticide Factsheets

TERA submitted by Oak Ridge National Laboratory and given the tracking designations of R-01-0002.The microorganism will be tested to determine whether it will produce light in the presence of trinitrotoluene (TNT) as a means of detecting TNT in soil.

Novel inexpensive fungi proteases: Production by solid state fermentation and characterization.

PubMed

Novelli, Paula Kern; Barros, Margarida Maria; Fleuri, Luciana Francisco

2016-05-01

A comparative study was carried out for proteases production using agroindustrial residues as substrate for solid state fermentation (SSF) of several fungal strains. High protease production was observed for most of the microorganisms studied, as well as very different biochemical characteristics, including activities at specific temperatures and a wide range of pH values. The enzymes produced were very different regarding optimum pH and they showed stability at 50 °C. Aspergillus oryzae showed stability at all pH values studied. Penicillium roquefortii and Aspergillus flavipes presented optimum activity at temperatures of 50 °C and 90 °C, respectively. Lyophilized protease from A. oryzae reached 1251.60 U/g and yield of 155010.66 U/kg of substrate. Therefore, the substrate as well as the microorganism strain can modify the biochemical character of the enzyme produced. The high protease activity and stability established plus the low cost of substrates, make these fungal proteases potential alternatives for the biotechnological industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Uncultured microorganisms as a source of secondary metabolites.

PubMed

Lewis, Kim; Epstein, Slava; D'Onofrio, Anthony; Ling, Losee L

2010-08-01

The vast majority of microbial species are 'uncultured' and do not grow under laboratory conditions. This has led to the development of a number of methods to culture these organisms in a simulated natural environment. Approaches include placing cells in chambers that allow diffusion of compounds from the natural environment, traps enclosed with porous membranes that specifically capture organisms forming hyphae--actinobacteria and microfungi, and growth in the presence of cultivable helper species. Repeated cultivation in situ produces domesticated variants that can grow on regular media in vitro, and can be scaled up for secondary metabolite production. The co-culture approach has led to the identification of the first class of growth factors for uncultured bacteria, iron-chelating siderophores. It appears that many uncultured organisms from diverse taxonomical groups have lost the ability to produce siderophores, and depend on neighboring species for growth. The new cultivation approaches allow for the exploitation of the secondary metabolite potential of the previously inaccessible microorganisms.

Novel anti-infective compounds from marine bacteria.

PubMed

Rahman, Hafizur; Austin, Brian; Mitchell, Wilfrid J; Morris, Peter C; Jamieson, Derek J; Adams, David R; Spragg, Andrew Mearns; Schweizer, Michael

2010-03-05

As a result of the continuous evolution of microbial pathogens towards antibiotic-resistance, there have been demands for the development of new and effective antimicrobial compounds. Since the 1960s, the scientific literature has accumulated many publications about novel pharmaceutical compounds produced by a diverse range of marine bacteria. Indeed, marine micro-organisms continue to be a productive and successful focus for natural products research, with many newly isolated compounds possessing potentially valuable pharmacological activities. In this regard, the marine environment will undoubtedly prove to be an increasingly important source of novel antimicrobial metabolites, and selective or targeted approaches are already enabling the recovery of a significant number of antibiotic-producing micro-organisms. The aim of this review is to consider advances made in the discovery of new secondary metabolites derived from marine bacteria, and in particular those effective against the so called "superbugs", including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE), which are largely responsible for the increase in numbers of hospital acquired, i.e., nosocomial, infections.

Probiotics production and alternative encapsulation methodologies to improve their viabilities under adverse environmental conditions.

PubMed

Coghetto, Chaline Caren; Brinques, Graziela Brusch; Ayub, Marco Antônio Záchia

2016-12-01

Probiotic products are dietary supplements containing live microorganisms producing beneficial health effects on the host by improving intestinal balance and nutrient absorption. Among probiotic microorganisms, those classified as lactic acid bacteria are of major importance to the food and feed industries. Probiotic cells can be produced using alternative carbon and nitrogen sources, such as agroindustrial residues, at the same time contributing to reduce process costs. On the other hand, the survival of probiotic cells in formulated food products, as well as in the host gut, is an essential nutritional aspect concerning health benefits. Therefore, several cell microencapsulation techniques have been investigated as a way to improve cell viability and survival under adverse environmental conditions, such as the gastrointestinal milieu of hosts. In this review, different aspects of probiotic cells and technologies of their related products are discussed, including formulation of culture media, and aspects of cell microencapsulation techniques required to improve their survival in the host.

Bioprospecting for microbial products that affect ice crystal formation and growth.

PubMed

Christner, Brent C

2010-01-01

At low temperatures, some organisms produce proteins that affect ice nucleation, ice crystal structure, and/or the process of recrystallization. Based on their ice-interacting properties, these proteins provide an advantage to species that commonly experience the phase change from water to ice or rarely experience temperatures above the melting point. Substances that bind, inhibit or enhance, and control the size, shape, and growth of ice crystals could offer new possibilities for a number of agricultural, biomedical, and industrial applications. Since their discovery more than 40 years ago, ice nucleating and structuring proteins have been used in cryopreservation, frozen food preparation, transgenic crops, and even weather modification. Ice-interacting proteins have demonstrated commercial value in industrial applications; however, the full biotechnological potential of these products has yet to be fully realized. The Earth's cold biosphere contains an almost endless diversity of microorganisms to bioprospect for microbial compounds with novel ice-interacting properties. Microorganisms are the most appropriate biochemical factories to cost effectively produce ice nucleating and structuring proteins on large commercial scales.

Effect of simulated microgravity on growth and production of exopolymeric substances of Micrococcus luteus space and earth isolates.

PubMed

Mauclaire, Laurie; Egli, Marcel

2010-08-01

Microorganisms tend to form biofilms on surfaces, thereby causing deterioration of the underlaying material. In addition, biofilm is a potential health risk to humans. Therefore, microorganism growth is not only an issue on Earth but also in manned space habitats like the International Space Station (ISS). The aim of the study was to identify physiological processes relevant for Micrococcus luteus attachment under microgravity conditions. The results demonstrate that simulated microgravity influences physiological processes which trigger bacterial attachment and biofilm formation. The ISS strains produced larger amounts of exopolymeric substances (EPS) compared with a reference strain from Earth. In contrast, M. luteus strains were growing faster, and Earth as well as ISS isolates produced a higher yield of biomass under microgravity conditions than under normal gravity. Furthermore, microgravity caused a reduction of the colloidal EPS production of ISS isolates in comparison with normal gravity, which probably influences biofilm thickness and stability as well.

Micro-organisms in latex and natural rubber coagula of Hevea brasiliensis and their impact on rubber composition, structure and properties.

PubMed

Salomez, M; Subileau, M; Intapun, J; Bonfils, F; Sainte-Beuve, J; Vaysse, L; Dubreucq, E

2014-10-01

Natural rubber, produced by coagulation of the latex from the tree Hevea brasiliensis, is an important biopolymer used in many applications for its outstanding properties. Besides polyisoprene, latex is rich in many nonisoprene components such as carbohydrates, proteins and lipids and thereby constitutes a favourable medium for the development of micro-organisms. The fresh rubber coagula obtained by latex coagulation are not immediately processed, allowing the development of various microbial communities. The time period between tree tapping and coagula processing is called maturation, during which an evolution of the properties of the corresponding dry natural rubber occurs. This evolution is partly related to the activity of micro-organisms and to the modification of the biochemical composition. This review synthesizes the current knowledge on microbial populations in latex and natural rubber coagula of H. brasiliensis and the changes they induce on the biochemistry and technical properties of natural rubber during maturation. © 2014 The Society for Applied Microbiology.

Survival of Streptococcus suis, Streptococcus dysgalactiae and Trueperella pyogenes in dry-cured Iberian pork shoulders and loins.

PubMed

Cardoso-Toset, F; Luque, I; Morales-Partera, A; Galán-Relaño, A; Barrero-Domínguez, B; Hernández, M; Gómez-Laguna, J

2017-02-01

Dry-cured hams, shoulders and loins of Iberian pigs are highly appreciated in national and international markets. Salting, additive addition and dehydration are the main strategies to produce these ready-to-eat products. Although the dry curing process is known to reduce the load of well-known food borne pathogens, studies evaluating the viability of other microorganisms in contaminated pork have not been performed. In this work, the efficacy of the dry curing process to eliminate three swine pathogens associated with pork carcass condemnation, Streptococcus suis, Streptococcus dysgalactiae and Trueperella pyogenes, was evaluated. Results of this study highlight that the dry curing process is a suitable method to obtain safe ready-to-eat products free of these microorganisms. Although salting of dry-cured shoulders had a moderate bactericidal effect, results of this study suggest that drying and ripening were the most important stages to obtain dry-cured products free of these microorganisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enterotoxigenic Escherichia coli and probiotics in swine: what the bleep do we know?

PubMed Central

DUBREUIL, Jean Daniel

2017-01-01

The concept of certain microorganisms conferring direct benefits to the host relates to the term “probiotic”. Probiotics are microorganisms, bacteria, or yeast that when administered orally in sufficient quantity can counteract the effect of pathogenic microorganisms. The gastrointestinal (GI) tract is the site where probiotics are believed to play the most important role. The proposed effects of probiotics include antagonism of pathogens, interference with adherence, competition for nutrients, enterotoxin inactivation, modulation of the immune response, and strengthening of the intestinal barrier. From birth to postweaning, piglets are very sensitive to gut colonisation by pathogens. Enterotoxigenic Escherichia coli represents one of the most common agents of swine diarrhoea. The enterotoxins produced by this E. coli virotype are responsible for the loss of electrolytes and water observed following infection. This review addresses more specifically the studies done during the last 10 years deciphering the molecular mechanisms at play between host cell and probiotic interactions in the swine GI tract. PMID:28785529

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

PubMed Central

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

2014-01-01

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

Microbiological Diversity Demonstrates the Potential which Collaboratively Metabolize Nitrogen Oxides ( NOx) under Smog Environmental Stress

NASA Astrophysics Data System (ADS)

Chen, X. Z.; Zhao, X. H.; Chen, X. P.

2018-03-01

Recently, smoggy weather has become a daily in large part of China because of rapidly economic growth and accelerative urbanization. Stressed on the smoggy situation and economic growth, the green and environment-friendly technology is necessary to reduce or eliminate the smog and promote the sustainable development of economy. Previous studies had confirmed that nitrogen oxides ( NOx ) is one of crucial factors which forms smog. Microorganisms have the advantages of quickly growth and reproduction and metabolic diversity which can collaboratively Metabolize various NOx. This study will design a kind of bacteria & algae cultivation system which can metabolize collaboratively nitrogen oxides in air and intervene in the local nitrogen cycle. Furthermore, the nitrogen oxides can be transformed into nitrogen gas or assembled in protein in microorganism cell by regulating the microorganism types and quantities and metabolic pathways in the system. Finally, the smog will be alleviated or eliminated because of reduction of nitrogen oxides emission. This study will produce the green developmental methodology.

Surfactant based enhanced oil recovery mediated by naturally occurring microorganisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, C.P.; Bala, G.A.; Duvall, M.L.

1991-01-01

Oil recovery experiments using Bacillus licheniformis JF-2 and a sucrose based nutrient were performed using Berea sandstone cores ranging in permeability from 85 to 510 md (0.084 to 0.503 {mu}m{sup 2}). Bacillus licheniformis JF-2, a surfactant producing microorganism isolated from an oilfield environment, is nonpathogenic and will not reduce sulfate. Oil recovery efficiencies (E{sub r}) for four different crude oils ranging from 19.1 to 38.1{degrees}API (0.9396 to 0.8343 g/cm{sup 3}) varied from 2.8 to 42.6% of the waterflood residual oil. Injection of cell-free'' supernatants resulted in E{sub r} values from 7.0 to 16.4%. Microbially-mediated systems reduced interfacial tension (IFT) aboutmore » 20 mN/m for four different crude oils. Following microbial flood experimentation microorganisms were distributed throughout the core (110 md (0.109 {mu}m{sup 2}) Berea sandstone) with a predominance of cells located near the outlet end. 34 refs., 6 figs., 7 tabs.« less

An evaluation of microorganisms for unconventional food regeneration schemes in CELSS - Research recommendations

NASA Technical Reports Server (NTRS)

Stokes, B. O.; Petersen, G. R.

1982-01-01

The benefits and deficiencies of various candidates for a controlled ecological life support system (CELSS) for manned spacecraft missions of at least 3-14 yr are discussed. Conventional plants are considered unacceptable due to their inefficient production of foodstuffs and overproduction of stems and leafy matter. The alternate concepts are algae and/or bacteria or chemical synthesis of food. Microorganisms are considered the most promising because of their direct use of CO2 and possible utilization of waste streams. Yeasts are cited as the most viable candidates, since a large data base and experience already exists in the commercial food industry. The addition of hydrogen bactria and solar-grown algae is recommended, together with genetic manipulation experiments to tailor the microorganisms to production of foodstuffs closer to the 70 percent carbohydrate, 20 percent protein, and 10 percent lipid optimal food currently accepted. The yeast strain, Hansenula polymorpha, has been successfully grown in methanol and encouraged to produce a 55 percent carbohydrate content.

Recent advances and industrial viewpoint for biological treatment of wastewaters by oleaginous microorganisms.

PubMed

Huang, Chao; Luo, Mu-Tan; Chen, Xue-Fang; Xiong, Lian; Li, Xiao-Mei; Chen, Xin-De

2017-05-01

Recently, technology of using oleaginous microorganisms for biological treatment of wastewaters has become one hot topic in biochemical and environmental engineering for its advantages such as easy for operation in basic bioreactor, having potential to produce valuable bio-products, efficient wastewaters treatment in short period, etc. To promote its industrialization, this article provides some comprehensive analysis of this technology such as its advances, issues, and outlook especially from industrial viewpoint. In detail, the types of wastewaters can be treated and the kinds of oleaginous microorganisms used for biological treatment are introduced, the potential of industrial application and issues (relatively low COD removal, low lipid yield, cost of operation, and lack of scale up application) of this technology are presented, and some critical outlook mainly on co-culture method, combination with other treatments, process controlling and adjusting are discussed systematically. By this article, some important information to develop this technology can be obtained. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quorum Quenching Agents: Resources for Antivirulence Therapy

PubMed Central

Tang, Kaihao; Zhang, Xiao-Hua

2014-01-01

The continuing emergence of antibiotic-resistant pathogens is a concern to human health and highlights the urgent need for the development of alternative therapeutic strategies. Quorum sensing (QS) regulates virulence in many bacterial pathogens, and thus, is a promising target for antivirulence therapy which may inhibit virulence instead of cell growth and division. This means that there is little selective pressure for the evolution of resistance. Many natural quorum quenching (QQ) agents have been identified. Moreover, it has been shown that many microorganisms are capable of producing small molecular QS inhibitors and/or macromolecular QQ enzymes, which could be regarded as a strategy for bacteria to gain benefits in competitive environments. More than 30 species of marine QQ bacteria have been identified thus far, but only a few of them have been intensively studied. Recent studies indicate that an enormous number of QQ microorganisms are undiscovered in the highly diverse marine environments, and these marine microorganism-derived QQ agents may be valuable resources for antivirulence therapy. PMID:24886865

Extremophiles as sources of inorganic bio-nanoparticles.

PubMed

Beeler, Erik; Singh, Om V

2016-09-01

Industrial use of nanotechnology in daily life has produced an emphasis on the safe and efficient production of nanoparticles (NPs). Traditional chemical oxidation and reduction methods are seen as inefficient, environmentally unsound, and often dangerous to those exposed and involved in NP manufacturing. However, utilizing microorganisms for biosynthesis of NPs allows efficient green production of a range of inorganic NPs, while maintaining specific size, shape, stability, and dispersity. Microorganisms living under harsh environmental conditions, called "Extremophiles," are one group of microorganisms being utilized for this biosynthesis. Extremophiles' unique living conditions have endowed them with various processes that enable NP biosynthesis. This includes a range of extremophiles: thermophiles, acidophilus, halophiles, psychrophiles, anaerobes, and some others. Fungi, bacteria, yeasts, and archaea, i.e. Ureibacillus thermosphaericus, and Geobacillus stearothermophilus, among others, have been established for NP biosynthesis. This article highlights the extremophiles and methods found to be viable candidates for the production of varying types of NPs, as well as interpreting selective methods used by the organisms to synthesize NPs.

Characterization of biofilm formation in natural water subjected to low-frequency electromagnetic fields.

PubMed

Mercier, Anne; Bertaux, Joanne; Lesobre, Jérôme; Gravouil, Kevin; Verdon, Julien; Imbert, Christine; Valette, Eric; Héchard, Yann

2016-01-01

Electromagnetic field (EMF) treatment has proven to be effective against mineral scaling in water systems. Therefore, it should be assessed for the treatment of other deposits such as biofilms. In this study, a commercial device producing low-frequency EMF (1-10 kHz) was applied to a reactor fed with natural water for 45 days. The treatment promoted the concentration of microorganisms in suspension and limited the amount of sessile microorganisms in the biofilm, as determined by the measurement of total DNA, qPCR and microscopy. The structure of the bacterial community was assessed by t-RFLP and pyrosequencing analysis. The results showed that EMF treatment affected both planktonic and sessile community composition. EMFs were responsible for a shift in classes of Proteobacteria during development of the biofilm. It may be speculated that the EMF treatment affected particle solubility and/or microorganism hydration. This study indicated that EMFs modulated biofilm formation in natural water.

Microbial fuel cells using Cellulomonas spp. with cellulose as fuel.

PubMed

Takeuchi, Yuya; Khawdas, Wichean; Aso, Yuji; Ohara, Hitomi

2017-03-01

Cellulomonas fimi, Cellulomonas biazotea, and Cellulomonas flavigena are cellulose-degrading microorganisms chosen to compare the degradation of cellulose. C. fimi degraded 2.5 g/L of cellulose within 4 days, which was the highest quantity among the three microorganisms. The electric current generation by the microbial fuel cell (MFC) using the cellulose-containing medium with C. fimi was measured over 7 days. The medium in the MFC was sampled every 24 h to quantify the degradation of cellulose, and the results showed that the electric current increased with the degradation of cellulose. The maximum electric power generated by the MFC was 38.7 mW/m 2 , and this numeric value was 63% of the electric power generated by an MFC with Shewanella oneidensis MR-1, a well-known current-generating microorganism. Our results showed that C. fimi was an excellent candidate to produce the electric current from cellulose via MFCs. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Methods to preserve potentially toxigenic fungi.

PubMed

Guimarães, Lucas Costa; Fernandes, Ana Paula; Chalfoun, Sara Maria; Batista, Luís Roberto

2014-01-01

Microorganisms are a source of many high-value compounds which are useful to every living being, such as humans, plants and animals. Since the process of isolating and improving a microorganism can be lengthy and expensive, preserving the obtained characteristic is of paramount importance, so the process does not need to be repeated. Fungi are eukaryotic, achlorophyllous, heterotrophic organisms, usually filamentous, absorb their food, can be either macro or microscopic, propagate themselves by means of spores and store glycogen as a source of storage. Fungi, while infesting food, may produce toxic substances such as mycotoxins. The great genetic diversity of the Kingdom Fungi renders the preservation of fungal cultures for many years relevant. Several international reference mycological culture collections are maintained in many countries. The methodologies that are most fit for preserving microorganisms for extended periods are based on lowering the metabolism until it reaches a stage of artificial dormancy. The goal of this study was to analyze three methods for potentially toxigenic fungal conservation (Castellani's, continuous subculture and lyophilization) and to identify the best among them.

The complex microbiota of raw milk.

PubMed

Quigley, Lisa; O'Sullivan, Orla; Stanton, Catherine; Beresford, Tom P; Ross, R Paul; Fitzgerald, Gerald F; Cotter, Paul D

2013-09-01

Here, we review what is known about the microorganisms present in raw milk, including milk from cows, sheep, goats and humans. Milk, due to its high nutritional content, can support a rich microbiota. These microorganisms enter milk from a variety of sources and, once in milk, can play a number of roles, such as facilitating dairy fermentations (e.g. Lactococcus, Lactobacillus, Streptococcus, Propionibacterium and fungal populations), causing spoilage (e.g. Pseudomonas, Clostridium, Bacillus and other spore-forming or thermoduric microorganisms), promoting health (e.g. lactobacilli and bifidobacteria) or causing disease (e.g. Listeria, Salmonella, Escherichia coli, Campylobacter and mycotoxin-producing fungi). There is also concern that the presence of antibiotic residues in milk leads to the development of resistance, particularly among pathogenic bacteria. Here, we comprehensively review these topics, while comparing the approaches, both culture-dependent and culture-independent, which can be taken to investigate the microbial composition of milk. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

One-pot bioethanol production from cellulose by co-culture of Acremonium cellulolyticus and Saccharomyces cerevisiae

PubMed Central

2012-01-01

Background While the ethanol production from biomass by consolidated bioprocess (CBP) is considered to be the most ideal process, simultaneous saccharification and fermentation (SSF) is the most appropriate strategy in practice. In this study, one-pot bioethanol production, including cellulase production, saccharification of cellulose, and ethanol production, was investigated for the conversion of biomass to biofuel by co-culture of two different microorganisms such as a hyper cellulase producer, Acremonium cellulolyticus C-1 and an ethanol producer Saccharomyces cerevisiae. Furthermore, the operational conditions of the one-pot process were evaluated for maximizing ethanol concentration from cellulose in a single reactor. Results Ethanol production from cellulose was carried out in one-pot bioethanol production process. A. cellulolyticus C-1 and S. cerevisiae were co-cultured in a single reactor. Cellulase producing-medium supplemented with 2.5 g/l of yeast extract was used for productions of both cellulase and ethanol. Cellulase production was achieved by A. cellulolyticus C-1 using Solka-Floc (SF) as a cellulase-inducing substrate. Subsequently, ethanol was produced with addition of both 10%(v/v) of S. cerevisiae inoculum and SF at the culture time of 60 h. Dissolved oxygen levels were adjusted at higher than 20% during cellulase producing phase and at lower than 10% during ethanol producing phase. Cellulase activity remained 8–12 FPU/ml throughout the one-pot process. When 50–300 g SF/l was used in 500 ml Erlenmeyer flask scale, the ethanol concentration and yield based on initial SF were as 8.7–46.3 g/l and 0.15–0.18 (g ethanol/g SF), respectively. In 3-l fermentor with 50–300 g SF/l, the ethanol concentration and yield were 9.5–35.1 g/l with their yields of 0.12–0.19 (g/g) respectively, demonstrating that the one-pot bioethanol production is a reproducible process in a scale-up bioconversion of cellulose to ethanol. Conclusion A. cellulolyticus cells produce cellulase using SF. Subsequently, the produced cellulase saccharifies the SF, and then liberated reducing sugars are converted to ethanol by S. cerevisiae. These reactions were carried out in the one-pot process with two different microorganisms in a single reactor, which does require neither an addition of extraneous cellulase nor any pretreatment of cellulose. Collectively, the one-pot bioethanol production process with two different microorganisms could be an alternative strategy for a practical bioethanol production using biomass. PMID:22938388

Endophytes as sources of antibiotics.

PubMed

Martinez-Klimova, Elena; Rodríguez-Peña, Karol; Sánchez, Sergio

2017-06-15

Until a viable alternative can be accessible, the emergence of resistance to antimicrobials requires the constant development of new antibiotics. Recent scientific efforts have been aimed at the bioprospecting of microorganisms' secondary metabolites, with special emphasis on the search for antimicrobial natural products derived from endophytes. Endophytes are microorganisms that inhabit the internal tissues of plants without causing apparent harm to the plant. The present review article compiles recent (2006-2016) literature to provide an update on endophyte research aimed at finding metabolites with antibiotic activities. We have included exclusively information on endophytes that produce metabolites capable of inhibiting the growth of bacterial, fungal and protozoan pathogens of humans, animals and plants. Where available, the identified metabolites have been listed. In this review, we have also compiled a list of the bacterial and fungal phyla that have been isolated as endophytes as well as the plant families from which the endophytes were isolated. The majority of endophytes that produce antibiotic metabolites belong to either phylum Ascomycota (kingdom Fungi) or to phylum Actinobacteria (superkingdom Bacteria). Endophytes that produce antibiotic metabolites were predominant, but certainly not exclusively, from the plant families Fabaceae, Lamiaceae, Asteraceae and Araceae, suggesting that endophytes that produce antimicrobial metabolites are not restricted to a reduced number of plant families. The locations where plants (and inhabiting endophytes) were collected from, according to the literature, have been mapped, showing that endophytes that produce bioactive compounds have been collected globally. Copyright © 2016 Elsevier Inc. All rights reserved.

Clostridium Perfringens Toxins Involved in Mammalian Veterinary Diseases

PubMed Central

Uzal, F. A.; Vidal, J. E.; McClane, B. A.; Gurjar, A. A.

2013-01-01

Clostridium perfringens is a gram-positive anaerobic rod that is classified into 5 toxinotypes (A, B, C, D, and E) according to the production of 4 major toxins, namely alpha (CPA), beta (CPB), epsilon (ETX) and iota (ITX). However, this microorganism can produce up to 16 toxins in various combinations, including lethal toxins such as perfringolysin O (PFO), enterotoxin (CPE), and beta2 toxin (CPB2). Most diseases caused by this microorganism are mediated by one or more of these toxins. The role of CPA in intestinal disease of mammals is controversial and poorly documented, but there is no doubt that this toxin is essential in the production of gas gangrene of humans and several animal species. CPB produced by C. perfringens types B and C is responsible for necrotizing enteritis and enterotoxemia mainly in neonatal individuals of several animal species. ETX produced by C. perfringens type D is responsible for clinical signs and lesions of enterotoxemia, a predominantly neurological disease of sheep and goats. The role of ITX in disease of animals is poorly understood, although it is usually assumed that the pathogenesis of intestinal diseases produced by C. perfringens type E is mediated by this toxin. CPB2, a necrotizing and lethal toxin that can be produced by all types of C. perfringens, has been blamed for disease in many animal species, but little information is currently available to sustain or rule out this claim. CPE is an important virulence factor for C. perfringens type A gastrointestinal disease in humans and dogs; however, the data implicating CPE in other animal diseases remains ambiguous. PFO does not seem to play a direct role as the main virulence factor for animal diseases, but it may have a synergistic role with CPA-mediated gangrene and ETX-mediated enterotoxemia. The recent improvement of animal models for C. perfringens infection and the use of toxin gene knock-out mutants have demonstrated the specific pathogenic role of several toxins of C. perfringens in animal disease. These research tools are helping us to establish the role of each C. perfringens toxin in animal disease, to investigate the in vivo mechanism of action of these toxins, and to develop more effective vaccines against diseases produced by these microorganisms. PMID:24511335

Tracing the Sources of Macrolide Antibiotics and Illicit Drugs into the Lower Colorado River Basin

EPA Science Inventory

A number of pharmaceuticals have been detected in surface waters across the United States. Antibiotics present in the environment can produce resistance in microorganisms, which could potentially have adverse effects on human health. In addition, while the ecotoxicological signif...

7 CFR 205.2 - Terms defined.

Code of Federal Regulations, 2013 CFR

2013-01-01

... not including such livestock feed. Annual seedling. A plant grown from seed that will complete its... microorganisms break down plant and animal materials into more available forms suitable for application to the soil. Compost must be produced through a process that combines plant and animal materials with an...

7 CFR 205.2 - Terms defined.

Code of Federal Regulations, 2012 CFR

2012-01-01

... not including such livestock feed. Annual seedling. A plant grown from seed that will complete its... microorganisms break down plant and animal materials into more available forms suitable for application to the soil. Compost must be produced through a process that combines plant and animal materials with an...

7 CFR 205.2 - Terms defined.

Code of Federal Regulations, 2011 CFR

2011-01-01

... not including such livestock feed. Annual seedling. A plant grown from seed that will complete its... microorganisms break down plant and animal materials into more available forms suitable for application to the soil. Compost must be produced through a process that combines plant and animal materials with an...

7 CFR 205.2 - Terms defined.

Code of Federal Regulations, 2014 CFR

2014-01-01

... not including such livestock feed. Annual seedling. A plant grown from seed that will complete its... microorganisms break down plant and animal materials into more available forms suitable for application to the soil. Compost must be produced through a process that combines plant and animal materials with an...

Characterizing a novel strain of Bacillus amyloliquefaciens BAC03 for potential biological control application

USDA-ARS?s Scientific Manuscript database

Aims: Identify and characterize a bacterial strain from suppressive soil, BAC03, evaluate its antimicrobial activity against Streptomyces scabies and other microorganisms, and characterize an antimicrobial substance produced by this strain. Methods and Results: Bacterial strain BAC03 (isolated from ...

Production of phytoalexins in peanut (Arachis hypogaea) seed elicited by selected microorganisms

USDA-ARS?s Scientific Manuscript database

Plants accumulate defensive phytoalexins in response to the presence of pathogens, which in turn produce phytoalexin-detoxification enzymes for successfully invading the plant host. The detoxification of a number of phytoalexins by phytopathogenic fungi has been elucidated for various host plant fam...

COMPARISON OF METHODS FOR DETECTION AND ENUMERATION OF AIRBORNE MICROORGANISMS COLLECTED BY LIQUID IMPINGEMENT

EPA Science Inventory

Bacterial agents and cell components can be spread as bioaerosols, producing infections and asthmatic problems. This study compares four methods for the detection and enumeration of aerosolized bacteria collected in an AGI-30 impinger. Changes in the total and viable concentratio...

Metabolic assessment of E. coli as a Biofactory for commercial products.

PubMed

Zhang, Xiaolin; Tervo, Christopher J; Reed, Jennifer L

2016-05-01

Metabolic engineering uses microorganisms to synthesize chemicals from renewable resources. Given the thousands of known metabolites, it is unclear what valuable chemicals could be produced by a microorganism and what native and heterologous reactions are needed for their synthesis. To answer these questions, a systematic computational assessment of Escherichia coli's potential ability to produce different chemicals was performed using an integrated metabolic model that included native E.coli reactions and known heterologous reactions. By adding heterologous reactions, a total of 1777 non-native products could theoretically be produced in E. coli under glucose minimal medium conditions, of which 279 non-native products have commercial applications. Synthesis pathways involving native and heterologous reactions were identified from eight central metabolic precursors to the 279 non-native commercial products. These pathways were used to evaluate the dependence on, and diversity of, native and heterologous reactions to produce each non-native commercial product, as well as to identify each product׳s closest central metabolic precursor. Analysis of the synthesis pathways (with 5 or fewer reaction steps) to non-native commercial products revealed that isopentenyl diphosphate, pyruvate, and oxaloacetate are the closest central metabolic precursors to the most non-native commercial products. Additionally, 4-hydroxybenzoate, tyrosine, and phenylalanine were found to be common precursors to a large number of non-native commercial products. Strains capable of producing high levels of these precursors could be further engineered to create strains capable of producing a variety of commercial non-native chemicals. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Emergence of extended-spectrum β-lactamase producing Enterobacter spp. in patients with bacteremia in a tertiary hospital in southern Brazil.

PubMed

Nogueira, Keite da Silva; Paganini, Maria Cristina; Conte, Andréia; Cogo, Laura Lúcia; Taborda de Messias Reason, Iara; da Silva, Márcio José; Dalla-Costa, Libera Maria

2014-02-01

Extended-spectrum β-lactamases (ESBLs) are increasingly prevalent in Enterobacter spp., posing a challenge to the treatment of infections caused by this microorganism. The purpose of this retrospective study was to evaluate the prevalence, risk factors, and clinical outcomes of inpatients with bacteremia caused by ESBL and non ESBL-producing Enterobacter spp. in a tertiary hospital over the period 2004-2008. The presence of blaCTX-M, blaTEM, blaSHV, and blaPER genes was detected by polymerase chain reaction (PCR) and nucleotide sequence analysis. Genetic similarity between strains was defined by pulsed-field gel electrophoresis (PFGE). Enterobacter spp. was identified in 205 of 4907 of the patients who had positive blood cultures during hospitalization. Of those cases, 41 (20%) were ESBL-producing Enterobacter spp. Nosocomial pneumonia was the main source of bacteremia caused by ESBL-producing Enterobacter spp. The presence of this microorganism was associated with longer hospital stays. The ESBL genes detected were: CTX-M-2 (23), CTX-M-59 (10), CTX-M-15 (1), SHV-12 (5), and PER-2 (2). While Enterobacter aerogenes strains showed mainly a clonal profile, Enterobacter cloacae strains were polyclonal. Although no difference in clinical outcomes was observed between patients with infections by ESBL-producing and non-ESBL-producing strains, the detection of ESBL in Enterobacter spp. resulted in the change of antimicrobials in 75% of cases, having important implications in the decision-making regarding adequate antimicrobial therapy. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Detergent composition comprising a cellulase containing cell-free fermentate produced from microorganism ATCC 55702 or mutant thereof

DOEpatents

Dees, H.C.

1998-07-14

Bacteria which produce large amounts of a cellulase-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques. 5 figs.

Diversity of culturable nocardioform actinomycetes from wastewater treatment plants in Spain and their role in the biodegradability of aromatic compounds.

PubMed

Soler, Albert; García-Hernández, Jorge; Zornoza, Andrés; Alonso, José Luis

2018-01-01

Currently, municipal and industrial wastewater treatment plants (WWTPs) are mainly focusing on reduction of biological oxygen demand and on the removal of nutrients. However, there are microorganisms that interfere with the process. In this environment, there is a large diversity of microorganisms that have not been studied in detail and that could provide real and practical solutions to the foaming problems. Among such microorganisms, Gram-positive actinomycete bacteria are of special interest because they are known for producing secondary metabolites as well as chemically diverse compounds and for their capacity to degrade recalcitrant pollutants. Three different media were chosen to isolate actinomycetes from 28 WWTPs in Spain. A total of 189 activated sludge samples were collected; 126 strains were isolated and identified to belong to 1 suborder, i.e. Corynebacterineae, and 7 genera, i.e. Corynebacterium, Dietzia, Gordonia, Mycobacterium, Rhodococcus, Tsukamurella and Williamsia. Furthermore, 71 strains were capable of biodegrading at least 1 aromatic product, and that 27 of them amplified for catA gene. The results of this research help us understand the complexity of the foam-forming microbial populations in Spain and it shows that WWTPs can be a good source of microorganisms that can degrade phenol or naphthalene.

Microorganisms in cryopreserved semen and culture media used in the in vitro production (IVP) of bovine embryos identified by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS).

PubMed

Zampieri, Dávila; Santos, Vanessa G; Braga, Patrícia A C; Ferreira, Christina R; Ballottin, Daniela; Tasic, Ljubica; Basso, Andréa C; Sanches, Bruno V; Pontes, José H F; da Silva, Bárbara Pereira; Garboggini, Fabiana Fantinatti; Eberlin, Marcos N; Tata, Alessandra

2013-09-01

Commercial cattle breeders produce their own herd offspring for the dairy and beef market using artificial insemination. The procedure involves sanitary risks associated with the collection and commercialization of the germplasm, and the in vitro production and transfer of the bovine embryos must be monitored by strict health surveillance. To avoid the spreading of infectious diseases, one must rely on using controlled and monitored germplasm, media, and reagents that are guaranteed free of pathogens. In this article, we investigated the use of a new mass spectrometric approach for fast and accurate identification of bacteria and fungi in bovine semen and in culture media employed in the embryo in vitro production process. The microorganisms isolated from samples obtained in a commercial bovine embryo IVP setting were identified in a few minutes by their conserved peptide/protein profile, obtained applying matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), matched against a commercial database. The successful microorganisms MS identification has been confirmed by DNA amplification and sequencing. Therefore, the MS technique seems to offer a powerful tool for rapid and accurate microorganism identification in semen and culture media samples. Copyright © 2013 Elsevier Inc. All rights reserved.

The hunt for the most-wanted chemolithoautotrophic spookmicrobes

PubMed Central

2018-01-01

ABSTRACT Microorganisms are the drivers of biogeochemical methane and nitrogen cycles. Essential roles of chemolithoautotrophic microorganisms in these cycles were predicted long before their identification. Dedicated enrichment procedures, metagenomics surveys and single-cell technologies have enabled the identification of several new groups of most-wanted spookmicrobes, including novel methoxydotrophic methanogens that produce methane from methylated coal compounds and acetoclastic ‘Candidatus Methanothrix paradoxum’, which is active in oxic soils. The resultant energy-rich methane can be oxidized via a suite of electron acceptors. Recently, ‘Candidatus Methanoperedens nitroreducens’ ANME-2d archaea and ‘Candidatus Methylomirabilis oxyfera’ bacteria were enriched on nitrate and nitrite under anoxic conditions with methane as an electron donor. Although ‘Candidatus Methanoperedens nitroreducens’ and other ANME archaea can use iron citrate as an electron acceptor in batch experiments, the quest for anaerobic methane oxidizers that grow via iron reduction continues. In recent years, the nitrogen cycle has been expanded by the discovery of various ammonium-oxidizing prokaryotes, including ammonium-oxidizing archaea, versatile anaerobic ammonium-oxidizing (anammox) bacteria and complete ammonium-oxidizing (comammox) Nitrospira bacteria. Several biogeochemical studies have indicated that ammonium conversion occurs under iron-reducing conditions, but thus far no microorganism has been identified. Ultimately, iron-reducing and sulfate-dependent ammonium-oxidizing microorganisms await discovery. PMID:29873717

Potential Impact of Microbial Activity on the Oxidant Capacity and the Organic Carbon Budget in Clouds (Invited)

NASA Astrophysics Data System (ADS)

Delort, A.

2013-12-01

Within cloud water, microorganisms are metabolically active; so they are suspected to contribute to atmospheric chemistry. This paper is focused on the interactions between microorganisms and Reactive Oxygenated Species present in cloud water since these chemical compounds are driving the oxidant capacity of the cloud system. For this, real cloud waters with contrasting features (marine, continental, urban) were sampled at the puy de Dôme mountain (France). They exhibit high microbial biodiversity and complex chemical composition. These media were incubated in the dark and subjected to UV-light radiation in specifically designed photo-bio-reactors. The concentrations of hydrogen peroxide (H2O2), organic compounds and the ATP/ADP ratio were monitored during the incubation period. Microorganisms remained metabolically active in the presence of hydroxyl radicals photo-produced from H2O2. This oxidant and major carbon compounds (formaldehyde and carboxylic acids) were biodegraded by the endogenous microflora. This work suggests that microorganisms could play a double role in atmospheric chemistry: first, they could directly metabolize organic carbon species; second they could reduce the available source of radicals due to their oxidative metabolism. Consequently, molecules such as H2O2 would be no longer available for photochemical or other chemical reactions, decreasing the cloud oxidant capacity.

Potential impact of microbial activity on the oxidant capacity and organic carbon budget in clouds

NASA Astrophysics Data System (ADS)

Vaïtilingom, Mickael; Deguillaume, Laurent; Vinatier, Virginie; Sancelme, Martine; Amato, Pierre; Chaumerliac, Nadine; Delort, Anne-Marie

2013-01-01

Within cloud water, microorganisms are metabolically active and, thus, are expected to contribute to the atmospheric chemistry. This article investigates the interactions between microorganisms and the reactive oxygenated species that are present in cloud water because these chemical compounds drive the oxidant capacity of the cloud system. Real cloud water samples with contrasting features (marine, continental, and urban) were taken from the puy de Dôme mountain (France). The samples exhibited a high microbial biodiversity and complex chemical composition. The media were incubated in the dark and subjected to UV radiation in specifically designed photo-bioreactors. The concentrations of H2O2, organic compounds, and the ATP/ADP ratio were monitored during the incubation period. The microorganisms remained metabolically active in the presence of ●OH radicals that were photo-produced from H2O2. This oxidant and major carbon compounds (formaldehyde and carboxylic acids) were biodegraded by the endogenous microflora. This work suggests that microorganisms could play a double role in atmospheric chemistry; first, they could directly metabolize organic carbon species, and second, they could reduce the available source of radicals through their oxidative metabolism. Consequently, molecules such as H2O2 would no longer be available for photochemical or other chemical reactions, which would decrease the cloud oxidant capacity.

The water kefir grain inoculum determines the characteristics of the resulting water kefir fermentation process.

PubMed

Laureys, D; De Vuyst, L

2017-03-01

To investigate the influence of the water kefir grain inoculum on the characteristics of the water kefir fermentation process. Three water kefir fermentation processes were started with different water kefir grain inocula and followed as a function of time regarding microbial species diversity, community dynamics, substrate consumption profile and metabolite production course. The inoculum determined the water kefir grain growth, the viable counts on the grains, the time until total carbohydrate exhaustion, the final metabolite concentrations and the microbial species diversity. There were always 2-10 lactic acid bacterial cells for every yeast cell and the majority of these micro-organisms was always present on the grains. Lactobacillus paracasei, Lactobacillus hilgardii, Lactobacillus nagelii and Saccharomyces cerevisiae were always present and may be the key micro-organisms during water kefir fermentation. Low water kefir grain growth was associated with small grains with high viable counts of micro-organisms, fast fermentation and low pH values, and was not caused by the absence of exopolysaccharide-producing lactic acid bacteria. The water kefir grain inoculum influences the microbial species diversity and characteristics of the fermentation process. A select group of key micro-organisms was always present during fermentation. This study allows a rational selection of a water kefir grain inoculum. © 2016 The Society for Applied Microbiology.

Process for converting cellulosic materials into fuels and chemicals

DOEpatents

Scott, C.D.; Faison, B.D.; Davison, B.H.; Woodward, J.

1994-09-20

A process is described for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attrition mill and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system. 1 fig.

Engineering microbes for efficient production of chemicals

DOEpatents

Gong, Wei; Dole, Sudhanshu; Grabar, Tammy; Collard, Andrew Christopher; Pero, Janice G; Yocum, R Rogers

2015-04-28

This present invention relates to production of chemicals from microorganisms that have been genetically engineered and metabolically evolved. Improvements in chemical production have been established, and particular mutations that lead to those improvements have been identified. Specific examples are given in the identification of mutations that occurred during the metabolic evolution of a bacterial strain genetically engineered to produce succinic acid. This present invention also provides a method for evaluating the industrial applicability of mutations that were selected during the metabolic evolution for increased succinic acid production. This present invention further provides microorganisms engineered to have mutations that are selected during metabolic evolution and contribute to improved production of succinic acid, other organic acids and other chemicals of commercial interest.

Microbiological Spoilage of Fruits and Vegetables

NASA Astrophysics Data System (ADS)

Barth, Margaret; Hankinson, Thomas R.; Zhuang, Hong; Breidt, Frederick

Consumption of fruit and vegetable products has dramatically increased in the United States by more than 30% during the past few decades. It is also estimated that about 20% of all fruits and vegetables produced is lost each year due to spoilage. The focus of this chapter is to provide a general background on microbiological spoilage of fruit and vegetable products that are organized in three categories: fresh whole fruits and vegetables, fresh-cut fruits and vegetables, and fermented or acidified vegetable products. This chapter will address characteristics of spoilage microorganisms associated with each of these fruit and vegetable categories including spoilage mechanisms, spoilage defects, prevention and control of spoilage, and methods for detecting spoilage microorganisms.

Processes for producing polyhydroxybutyrate and related polyhydroxyalkanoates in the plastids of higher plants

DOEpatents

Somerville, C.R.; Nawrath, C.; Poirier, Y.

1997-03-11

The present invention relates to a process for producing poly-D-(-)-3-hydroxybutyric acid (PHB) and related polyhydroxyalkanoates (PHA) in the plastids of plants. The production of PHB is accomplished by genetically transforming plants with modified genes from microorganisms. The genes encode the enzymes required to synthesize PHB from acetyl-CoA or related metabolites and are fused with additional plant sequences for targeting the enzymes to the plastid. 37 figs.

Diversity and function of the Antarctic krill microorganisms from Euphausia superba

NASA Astrophysics Data System (ADS)

Cui, Xiaoqiu; Zhu, Guoliang; Liu, Haishan; Jiang, Guoliang; Wang, Yi; Zhu, Weiming

2016-11-01

The diversity and ecological function of microorganisms associated with Euphausia superba, still remain unknown. This study identified 75 microbial isolates from E. superba, that is 42 fungi and 33 bacteria including eight actinobacteria. And all the isolates showed NaF tolerance in conformity with the nature of the fluoride krill. The maximum concentration was 10%, 3% and 0.5% NaF for actinobacteria, bacteria and fungi, respectively. The results demonstrated that 82.4% bacteria, 81.3% actinobacteria and 12.3% fungi produced antibacterial metabolites against pathogenic bacteria without NaF; the MIC value reached to 3.9 μg/mL. In addition, more than 60% fungi produced cytotoxic metabolites against A549, MCF-7 or K562 cell lines. The presence of NaF led to a reduction in the producing antimicrobial compounds, but stimulated the production of cytotoxic compounds. Furthermore, seven cytotoxic compounds were identified from the metabolites of Penicillium citrinum OUCMDZ4136 under 0.5% NaF, with the IC50 values of 3.6-13.1 μM for MCF-7, 2.2-19.8 μM for A549 and 5.4-15.4 μM for K562, respectively. These results indicated that the krill microbes exert their chemical defense by producing cytotoxic compounds to the mammalians and antibacterial compounds to inhibiting the pathogenic bacteria.

Isolation and identification of biocellulose-producing bacterial strains from Malaysian acidic fruits.

PubMed

Voon, W W Y; Rukayadi, Y; Meor Hussin, A S

2016-05-01

Biocellulose (BC) is pure extracellular cellulose produced by several species of micro-organisms that has numerous applications in the food, biomedical and paper industries. However, the existing biocellulose-producing bacterial strain with high yield was limited. The aim of this study was to isolate and identify the potential biocellulose-producing bacterial isolates from Malaysian acidic fruits. One hundred and ninety-three bacterial isolates were obtained from 19 local acidic fruits collected in Malaysia and screened for their ability to produce BC. A total of 15 potential bacterial isolates were then cultured in standard Hestrin-Schramm (HS) medium statically at 30°C for 2 weeks to determine the BC production. The most potent bacterial isolates were identified using 16S rRNA gene sequence analysis, morphological and biochemical characteristics. Three new and potent biocellulose-producing bacterial strains were isolated from soursop fruit and identified as Stenotrophomonas maltophilia WAUPM42, Pantoea vagans WAUPM45 and Beijerinckia fluminensis WAUPM53. Stenotrophomonas maltophilia WAUPM42 was the most potent biocellulose-producing bacterial strain that produced the highest amount of BC 0·58 g l(-1) in standard HS medium. Whereas, the isolates P. vagans WAUPM45 and B. fluminensis WAUPM53 showed 0·50 and 0·52 g l(-1) of BC production, respectively. Biocellulose (BC) is pure extracellular cellulose that is formed by many micro-organisms in the presence of carbon source and acidic condition. It can replace plant-based cellulose in multifarious applications due to its unique characteristics. In this study, three potential biocellulose-producing bacterial strains were obtained from Malaysian acidic fruits and identified as Stenotrophomonas maltophilia WAUPM42, Pantoea vagans WAUPM45 and Beijerinckia fluminensis WAUPM53. This study reports for the first time the new biocellulose-producing bacterial strains isolated from Malaysian acidic fruits. © 2016 The Society for Applied Microbiology.

Using enzymes and microorganisms to modify the mycotoxin deoxynivalenol

USDA-ARS?s Scientific Manuscript database

Deoxynivalenol (DON) is a trichothecene mycotoxin produced by the fungus Fusarium graminearum that contaminates staple crops such as wheat, barley, and maize when they are infected with this fungus. New strategies are needed to mitigate DON. We screened for microbes that could grow in the presence o...

Microorganisms and antifungal properties associated with noni (Morinda citrifolia) fruit and fermented juice in Hawaii

USDA-ARS?s Scientific Manuscript database

Noni (Morinda citrifolia), a medicinal plant grown in Hawaii and other Polynesian regions, is reportedly therapeutic for diabetes, high blood pressure, and certain types of cancer. Noni fruit often produce fermented juice that differs in chemical, physical and microbial properties. To determine ho...

INVESTIGATION OF DISINFECTION BY-PRODUCTS IN DRINKING WATER USING SOLID-PHASE EXTRACTION AND GAS CHROMATOGRAPHY/MASS SPECTROMETRY

EPA Science Inventory

Disinfection by-products (DBPs) result from the interaction of natural organic matter and bromide with chemical disinfectants, such as chlorine, added to drinking water to inactivate disease-producing microorganisms. These DBPs are monitored and regulated because of their possibl...

Regulation of Hexose and Pentose Metabolism by "Escherichia coli"

ERIC Educational Resources Information Center

Desai, Tasha A.

2009-01-01

Microorganisms can be used to produce a variety of chemicals such as drugs, enzymes, and fuels from different sugars. Traditionally, these processes have involved a single feedstock, most often glucose. More recently, significant effort has been devoted towards developing processes that directly use plant-based material as the feedstock. One…

CONSTRUCTED WETLANDS VS. RETENTION PONDS BMPS: THE ROLE OF VEGETATION IN IMPROVED POLLUTANT MANAGEMENT FOR URBAN STORMWATER TREATMENT

EPA Science Inventory

Increased urbanization has resulted in a larger percentage of impervious areas that produce large quantities of stormwater runoff and contribute significant amounts of debris and pollutants (e.g., litter, oils, heavy metals, sediments, nutrients, organic matter, and microorganism...

Impact of potential fermentation inhibitors present in sweet sorghum sugar solutions

USDA-ARS?s Scientific Manuscript database

In this work, the fermentation of the sweet sorghum sugars sucrose, glucose, and fructose to ethanol was studied in the presence of acetic, lactic and aconitic acid, which are present in the juice or produced by microorganisms during prolonged storage of harvested materials or juice. An industrial s...

21 CFR 184.1318 - Glucono delta-lactone.

Code of Federal Regulations, 2012 CFR

2012-04-01

... crystallization from the aqueous solution of gluconic acid. Gluconic acid may be produced by the oxidation of D-glucose with bromine water, by the oxidation of D-glucose by microorganisms that are nonpathogenic and nontoxicogenic to man or other animals, or by the oxidation of D-glucose with enzymes derived from these...

21 CFR 184.1318 - Glucono delta-lactone.

Code of Federal Regulations, 2013 CFR

2013-04-01

... crystallization from the aqueous solution of gluconic acid. Gluconic acid may be produced by the oxidation of D-glucose with bromine water, by the oxidation of D-glucose by microorganisms that are nonpathogenic and nontoxicogenic to man or other animals, or by the oxidation of D-glucose with enzymes derived from these...

21 CFR 173.140 - Esterase-lipase derived from Mucor miehei.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.140 Esterase-lipase derived from Mucor miehei. Esterase-lipase enzyme, consisting of enzyme derived from Mucor miehei var. Cooney et Emerson by... Emerson is nonpathogenic and nontoxic in man or other animals. (c) The enzyme is produced by a process...

21 CFR 173.140 - Esterase-lipase derived from Mucor miehei.

Code of Federal Regulations, 2014 CFR

2014-04-01

... (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.140 Esterase-lipase derived from Mucor miehei. Esterase-lipase enzyme, consisting of enzyme... animals. (c) The enzyme is produced by a process which completely removes the organism Mucor miehei var...

21 CFR 173.140 - Esterase-lipase derived from Mucor miehei.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.140 Esterase-lipase derived from Mucor miehei. Esterase-lipase enzyme, consisting of enzyme derived from Mucor miehei var. Cooney et Emerson by... Emerson is nonpathogenic and nontoxic in man or other animals. (c) The enzyme is produced by a process...

21 CFR 173.150 - Milk-clotting enzymes, microbial.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Milk-clotting enzymes, microbial. 173.150 Section... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.150 Milk-clotting enzymes, microbial. Milk-clotting enzyme produced by pure-culture fermentation process may be safely used in the production...

21 CFR 173.150 - Milk-clotting enzymes, microbial.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Milk-clotting enzymes, microbial. 173.150 Section... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.150 Milk-clotting enzymes, microbial. Milk-clotting enzyme produced by pure-culture fermentation process may be safely used in the production...

21 CFR 173.150 - Milk-clotting enzymes, microbial.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Milk-clotting enzymes, microbial. 173.150 Section... (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.150 Milk-clotting enzymes, microbial. Milk-clotting enzyme produced by pure-culture...

21 CFR 173.140 - Esterase-lipase derived from Mucor miehei.

Code of Federal Regulations, 2011 CFR

2011-04-01

... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.140 Esterase-lipase derived from Mucor miehei. Esterase-lipase enzyme, consisting of enzyme derived from Mucor miehei var. Cooney et Emerson by... Emerson is nonpathogenic and nontoxic in man or other animals. (c) The enzyme is produced by a process...

21 CFR 173.140 - Esterase-lipase derived from Mucor miehei.

Code of Federal Regulations, 2010 CFR

2010-04-01

... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.140 Esterase-lipase derived from Mucor miehei. Esterase-lipase enzyme, consisting of enzyme derived from Mucor miehei var. Cooney et Emerson by... Emerson is nonpathogenic and nontoxic in man or other animals. (c) The enzyme is produced by a process...

21 CFR 173.150 - Milk-clotting enzymes, microbial.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Milk-clotting enzymes, microbial. 173.150 Section... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.150 Milk-clotting enzymes, microbial. Milk-clotting enzyme produced by pure-culture fermentation process may be safely used in the production...

Characterization of growth inhibition of oral bacteria by sophorolipid using a microplate-format assay

USDA-ARS?s Scientific Manuscript database

Sophorolipid (SL) is a class of glycolipid biosurfactant produced by yeast and has potent antimicrobial activity against many microorganisms. In this paper, a microplate-based method was developed to characterize the growth inhibition by SL on five representative species of caries-causing oral bact...

Dual effectiveness of ascorbic acid and ethanol combined treatment to inhibit browning and inactivate pathogens on fresh-cut apples

USDA-ARS?s Scientific Manuscript database

Commercially-produced apple wedges have recently been associated with several recalls due to foodborne pathogen contamination. The fresh-cut industry faces a major technical challenge due to the incompatibility between chemicals used to control spoilage and pathogenic microorganisms (usually oxidize...

Development of a quail embryo model for the detection of botulinum neurotoxin activity

USDA-ARS?s Scientific Manuscript database

Clostridium botulinum is a ubiquitous microorganism that under anaerobic conditions produces botulinum neurotoxins. In regards to both food-borne illness and the potential use of botulinum toxin as a biological weapon, the capability to assess the amount of toxin in a food or environmental sample e...

Quantification of transcriptome responses of the rumen epithelium to butyrate infusion

USDA-ARS?s Scientific Manuscript database

Short-chain fatty acids (SCFAs), such as butyrate, produced by gut microorganisms play an important role in energy metabolism and physiology in ruminants as well as in human health. Butyrate is a preferred substrate in the rumen epithelium where approximately 90% of butyrate is metabolized. Additi...

Gene coding for the E1 endoglucanase

DOEpatents

Thomas, Steven R.; Laymon, Robert A.; Himmel, Michael E.

1996-01-01

The gene encoding Acidothermus cellulolyticus E1 endoglucanase is cloned and expressed in heterologous microorganisms. A new modified E1 endoglucanase enzyme is produced along with variants of the gene and enzyme. The E1 endoglucanase is useful for hydrolyzing cellulose to sugars for simultaneous or later fermentation into alcohol.

Gene coding for the E1 endoglucanase

DOEpatents

Thomas, S.R.; Laymon, R.A.; Himmel, M.E.

1996-07-16

The gene encoding Acidothermus cellulolyticus E1 endoglucanase is cloned and expressed in heterologous microorganisms. A new modified E1 endoglucanase enzyme is produced along with variants of the gene and enzyme. The E1 endoglucanase is useful for hydrolyzing cellulose to sugars for simultaneous or later fermentation into alcohol. 6 figs.

Gamma irradiation reduces the survival and regrowth of inoculated antibiotic-resistant bacteria and antibiotic resistant genes on romaine lettuce

USDA-ARS?s Scientific Manuscript database

Introduction: Gamma irradiation effectively reduces foodborne pathogens and spoilage microorganisms on fresh produce. However, limited research is available regarding the effect of gamma irradiation on the survival and regrowth of antibiotic-resistant bacteria (ARB) or the persistence of antibiotic ...

Synthesis of three advanced biofuels from ionic liquid-pretreated switchgrass using engineered Escherichia coli

PubMed Central

Bokinsky, Gregory; Peralta-Yahya, Pamela P.; George, Anthe; Holmes, Bradley M.; Steen, Eric J.; Dietrich, Jeffrey; Soon Lee, Taek; Tullman-Ercek, Danielle; Voigt, Christopher A.; Simmons, Blake A.; Keasling, Jay D.

2011-01-01

One approach to reducing the costs of advanced biofuel production from cellulosic biomass is to engineer a single microorganism to both digest plant biomass and produce hydrocarbons that have the properties of petrochemical fuels. Such an organism would require pathways for hydrocarbon production and the capacity to secrete sufficient enzymes to efficiently hydrolyze cellulose and hemicellulose. To demonstrate how one might engineer and coordinate all of the necessary components for a biomass-degrading, hydrocarbon-producing microorganism, we engineered a microorganism naïve to both processes, Escherichia coli, to grow using both the cellulose and hemicellulose fractions of several types of plant biomass pretreated with ionic liquids. Our engineered strains express cellulase, xylanase, beta-glucosidase, and xylobiosidase enzymes under control of native E. coli promoters selected to optimize growth on model cellulosic and hemicellulosic substrates. Furthermore, our strains grow using either the cellulose or hemicellulose components of ionic liquid-pretreated biomass or on both components when combined as a coculture. Both cellulolytic and hemicellulolytic strains were further engineered with three biofuel synthesis pathways to demonstrate the production of fuel substitutes or precursors suitable for gasoline, diesel, and jet engines directly from ionic liquid-treated switchgrass without externally supplied hydrolase enzymes. This demonstration represents a major advance toward realizing a consolidated bioprocess. With improvements in both biofuel synthesis pathways and biomass digestion capabilities, our approach could provide an economical route to production of advanced biofuels. PMID:22123987

New insights into the ecological interaction between grape berry microorganisms and Drosophila flies during the development of sour rot.

PubMed

Barata, André; Santos, Sara Correia; Malfeito-Ferreira, Manuel; Loureiro, Virgílio

2012-08-01

In this work, we studied the ecological interactions between grape berry microorganisms and Drosophila sp. flies involved in sour rot disease during grape ripening. After veráison the total microbial counts of grape berries affected by sour rot increased from about 2 log CFU/g of berries to more than 7 log CFU/g. Berry damage provoked a clear shift in yeast diversity from basidiomycetes to ascomycetous fermentative species. The latter were mostly Pichia terricola, Hanseniaspora uvarum, Candida zemplinina, and Zygoascus hellenicus. However, these species were not able to produce the metabolites characteristic of sour rot (gluconic and acetic acids) in inoculated berries. On the contrary, the acetic acid bacteria Gluconacetobacter saccharivorans produced high levels of these acids, mainly when berries were incubated in the presence of the insect Drosophila sp. Sour rot was not observed when grape bunches were physically separated from insects, even when berries were artificially injured. The wounds made in berry skin healed in the absence of insects, thus preventing the development of sour rot. Therefore, in the vineyard, the induction of sour rot depends on the contamination of wounded berries by a microbial consortium--yeasts and acetic acid bacteria--transported by drosophilid insects which disseminate sour rot among damaged berries. In the absence of these insects, plant defense mechanisms are effective and lead to skin healing, preventing disease spread. Thus, we showed that Drosophila sp. act as a vector for microorganisms associated with grape sour rot disease.

Effects of the 3D-clinorotation on endogenous substances of broccoli sprout (Brassica oleracea var. italica) and its food safety

NASA Astrophysics Data System (ADS)

Hiraishi, K.; Tomita-Yokotani, K.; Wakabayashi, K.; Hashimoto, H.; Miyagawa, T.; Yamashita, M.

Habitation in outer space is one of our challenges in this century We are studying on space agriculture to provide foods for space living people However careful assessment should be made on the effects of exotic environment on the endogenous production of biologically active substances and food safety of plants cultivated in space Broccoli sprout Brassica oleracea var italica is known to produce sulforaphane 4-methylsulfinybutyl isothiocyanate which is effective to function as an antioxidant and enhance immunity Because of such substance it is recognized to be good food materials Broccoli sprouts were then cultivated for 3 days under the 3D-clinorotation The amount of sulforaphane produced by this treatment showed no significant difference compared to the ground control Secondly we examined population of microorganisms adhered on the surface of sprout cultivated under the 3D-clinorotation Number of the microorganisms colony formed was statistically higher than the control Mold species was identified to penicillium sp based on the microscopic observation Poor construction of plant cell wall elements cellulose lignin etc is well known effects of microgravity Defense function of the broccoli plant cells might be weakened against microorganism We also speculate other possible causes for the high rate of contamination such as photosynthetic activity of the plant or microclimate air flow heat transport and humidity around the seedling affected by pseudo-microgravity or the 3D-clinorotation Those factors may relate to the difference in proliferation

Cold atmospheric plasma activity on microorganisms. A study on the influence of the treatment time and surface

NASA Astrophysics Data System (ADS)

Xaplanteris, C. L.; Filippaki, E. D.; Christodoulakis, J. K.; Kazantzaki, M. A.; Tsakalos, E. P.; Xaplanteris, L. C.

2015-08-01

The second half of the 20th century can be characterized and named as the `plasma era', as the plasma gathered scientific interest because of its special physical behaviour. Thus, it was considered as the fourth material state and the plasma physics began to form consequently. In addition to this, many important applications of plasma were discovered and put to use. Especially, in last few decades, there has been an increased interest in the use of cold atmospheric plasma in bio-chemical applications. Until now, thermal plasma has been commonly used in many bio-medical and other applications; however, more recent efforts have shown that plasma can also be produced at lower temperature (close to the environment temperature) by using ambient air in an open space (in atmospheric pressure). However, two aspects remain neglected: firstly, low-temperature plasma production with a large area, and secondly, acquiring the necessary knowledge and understanding the relevant interaction mechanisms of plasma species with microorganisms. These aspects are currently being investigated at the `Demokritos' Plasma Laboratory in Athens, Greece with radio frequency (27.12 MHz and it integer harmonics)-driven sub-atmospheric pressure plasma (100 Pa). The first aspect was achieved with atmospheric plasma being produced at a low temperature (close to the environment temperature) and in a large closed space systems. Regarding the plasma effect on living microorganisms, preliminary experiments and findings have already been carried out and many more have been planned for the near future.

Health benefits of fermented foods.

PubMed

Şanlier, Nevin; Gökcen, Büşra Başar; Sezgin, Aybüke Ceyhun

2017-09-25

In the past, the beneficial effects of fermented foods on health were unknown, and so people primarily used fermentation to preserve foods, enhance shelf life, and improve flavour. Fermented foods became an important part of the diet in many cultures, and over time fermentation has been associated with many health benefits. Because of this, the fermentation process and the resulting fermented products have recently attracted scientific interest. In addition, microorganisms contributing to the fermentation process have recently been associated with many health benefits, and so these microorganisms have become another focus of attention. Lactic acid bacteria (LAB) have been some of the most studied microorganisms. During fermentation, these bacteria synthesize vitamins and minerals, produce biologically active peptides with enzymes such as proteinase and peptidase, and remove some non-nutrients. Compounds known as biologically active peptides, which are produced by the bacteria responsible for fermentation, are also well known for their health benefits. Among these peptides, conjugated linoleic acids (CLA) have a blood pressure lowering effect, exopolysaccharides exhibit prebiotic properties, bacteriocins show anti-microbial effects, sphingolipids have anti-carcinogenic and anti-microbial properties, and bioactive peptides exhibit anti-oxidant, anti-microbial, opioid antagonist, anti-allergenic, and blood pressure lowering effects. As a result, fermented foods provide many health benefits such as anti-oxidant, anti-microbial, anti-fungal, anti-inflammatory, anti-diabetic and anti-atherosclerotic activity. However, some studies have shown no relationship between fermented foods and health benefits. Therefore, this paper aims to investigate the health effects of fermented foods.

Antimicrobial potential of actinobacteria isolated from the rhizosphere of the Caatinga biome plant Caesalpinia pyramidalis Tul.

PubMed

Silva-Lacerda, G R; Santana, R C F; Vicalvi-Costa, M C V; Solidônio, E G; Sena, K X F R; Lima, G M S; Araújo, J M

2016-03-04

Actinobacteria are known to produce various secondary metabolites having antibiotic effects. This study assessed the antimicrobial potential of actinobacteria isolated from the rhizosphere of Caesalpinia pyramidalis Tul. from the Caatinga biome. Sixty-eight actinobacteria isolates were evaluated for antimicrobial activity against different microorganisms by disk diffusion and submerged fermentation, using different culture media, followed by determination of minimum inhibitory concentration (MIC) and chemical prospecting of the crude extract. Of the isolates studied, 52.9% of those isolated at 37°C and 47.05% of those isolated at 45°C had activity against Bacillus subtilis, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Fusarium moniliforme, and Candida albicans. When compared with others actinobacteria, the isolate C1.129 stood out with better activity and was identified by 16S rDNA gene analysis as Streptomyces parvulus. The crude ethanol extract showed an MIC of 0.97 μg/mL for MRSA and B. subtilis, while the ethyl acetate extract showed MIC of 3.9 μg/mL for S. aureus and MRSA, showing the greatest potential among the metabolites produced. Chemical prospecting revealed the presence of mono/sesquiterpenes, proanthocyanidin, triterpenes, and steroids in both crude extracts. This study evaluates S. parvulus activity against multi-resistant microorganisms such as MRSA. Thus, it proves that low-fertility soil, as is found in the Caatinga, may contain important microorganisms for the development of new antimicrobial drugs.

Metagenomic and Metatranscriptomic Analyses Reveal the Structure and Dynamics of a Dechlorinating Community Containing Dehalococcoides mccartyi and Corrinoid-Providing Microorganisms under Cobalamin-Limited Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Men, Yujie; Yu, Ke; Bælum, Jacob

ABSTRACT The aim of this study is to obtain a systems-level understanding of the interactions betweenDehalococcoidesand corrinoid-supplying microorganisms by analyzing community structures and functional compositions, activities, and dynamics in trichloroethene (TCE)-dechlorinating enrichments. Metagenomes and metatranscriptomes of the dechlorinating enrichments with and without exogenous cobalamin were compared. Seven putative draft genomes were binned from the metagenomes. At an early stage (2 days), more transcripts of genes in theVeillonellaceaebin-genome were detected in the metatranscriptome of the enrichment without exogenous cobalamin than in the one with the addition of cobalamin. Among these genes, sporulation-related genes exhibited the highest differential expression when cobalamin wasmore » not added, suggesting a possible release route of corrinoids from corrinoid producers. Other differentially expressed genes include those involved in energy conservation and nutrient transport (including cobalt transport). The most highly expressed corrinoidde novobiosynthesis pathway was also assigned to theVeillonellaceaebin-genome. Targeted quantitative PCR (qPCR) analyses confirmed higher transcript abundances of those corrinoid biosynthesis genes in the enrichment without exogenous cobalamin than in the enrichment with cobalamin. Furthermore, the corrinoid salvaging and modification pathway ofDehalococcoideswas upregulated in response to the cobalamin stress. This study provides important insights into the microbial interactions and roles played by members of dechlorinating communities under cobalamin-limited conditions. IMPORTANCEThe key chloroethene-dechlorinating bacteriumDehalococcoides mccartyiis a cobalamin auxotroph, thus acquiring corrinoids from other community members. Therefore, it is important to investigate the microbe-microbe interactions betweenDehalococcoidesand the corrinoid-providing microorganisms in a community. This study provides systems-level information, i.e., taxonomic and functional compositions and dynamics of the supportive microorganisms in dechlorinating communities under different cobalamin conditions. The findings shed light on the important roles ofVeillonellaceaespecies in the communities compared to other coexisting community members in producing and providing corrinoids forDehalococcoidesspecies under cobalamin-limited conditions.« less

Effect of different film packaging on microbial growth in minimally processed cactus pear (Opuntia ficus-indica).

PubMed

Palma, A; Mangia, N P; Fadda, A; Barberis, A; Schirra, M; D'Aquino, S

2013-01-01

Microorganisms are natural contaminants of fresh produce and minimally processed products, and contamination arises from a number of sources, including the environment, postharvest handling and processing. Fresh-cut products are particularly susceptible to microbial contaminations because of the changes occurring in the tissues during processing. In package gas composition of modified atmosphere packaging (MAP) in combination with low storage temperatures besides reducing physiological activity of packaged produce, can also delay pathogen growth. Present study investigated on the effect of MAPs, achieved with different plastic films, on microbial growth of minimally processed cactus pear (Opuntio ficus-indica) fruit. Five different plastic materials were used for packaging the manually peeled fruit. That is: a) polypropylene film (Termoplast MY 40 micron thickness, O2 transmission rate 300 cc/m2/24h); b) polyethylene film (Bolphane BHE, 11 micron thickness, O2 transmission rate 19000 cc/m2/24h); c) polypropylene laser-perforated films (Mach Packaging) with 8, 16 or 32 100-micron holes. Total aerobic psychrophilic, mesophilic microorganisms, Enterobacteriaceae, yeast, mould populations and in-package CO2, O2 and C2H4 were determined at each storage time. Different final gas compositions, ranging from 7.8 KPa to 17.1 KPa O2, and 12.7 KPa to 2.6 KPa CO2, were achieved with MY and micro perforated films, respectively. Differences were detected in the mesophilic, Enterobacteriaceae and yeast loads, while no difference was detected in psychrophilic microorganisms. At the end of storage, microbial load in fruits sealed with MY film was significantly lower than in those sealed with BHE and micro perforated films. Furthermore, fruits packed with micro-perforated films showed the highest microbial load. This occurrence may in part be related to in-package gas composition and in part to a continuous contamination of microorganisms through micro-holes.

Metagenomic and Metatranscriptomic Analyses Reveal the Structure and Dynamics of a Dechlorinating Community Containing Dehalococcoides mccartyi and Corrinoid-Providing Microorganisms under Cobalamin-Limited Conditions

PubMed Central

Yu, Ke; Bælum, Jacob; Gao, Ying; Tremblay, Julien; Prestat, Emmanuel; Stenuit, Ben; Tringe, Susannah G.; Jansson, Janet; Zhang, Tong; Alvarez-Cohen, Lisa

2017-01-01

ABSTRACT The aim of this study is to obtain a systems-level understanding of the interactions between Dehalococcoides and corrinoid-supplying microorganisms by analyzing community structures and functional compositions, activities, and dynamics in trichloroethene (TCE)-dechlorinating enrichments. Metagenomes and metatranscriptomes of the dechlorinating enrichments with and without exogenous cobalamin were compared. Seven putative draft genomes were binned from the metagenomes. At an early stage (2 days), more transcripts of genes in the Veillonellaceae bin-genome were detected in the metatranscriptome of the enrichment without exogenous cobalamin than in the one with the addition of cobalamin. Among these genes, sporulation-related genes exhibited the highest differential expression when cobalamin was not added, suggesting a possible release route of corrinoids from corrinoid producers. Other differentially expressed genes include those involved in energy conservation and nutrient transport (including cobalt transport). The most highly expressed corrinoid de novo biosynthesis pathway was also assigned to the Veillonellaceae bin-genome. Targeted quantitative PCR (qPCR) analyses confirmed higher transcript abundances of those corrinoid biosynthesis genes in the enrichment without exogenous cobalamin than in the enrichment with cobalamin. Furthermore, the corrinoid salvaging and modification pathway of Dehalococcoides was upregulated in response to the cobalamin stress. This study provides important insights into the microbial interactions and roles played by members of dechlorinating communities under cobalamin-limited conditions. IMPORTANCE The key chloroethene-dechlorinating bacterium Dehalococcoides mccartyi is a cobalamin auxotroph, thus acquiring corrinoids from other community members. Therefore, it is important to investigate the microbe-microbe interactions between Dehalococcoides and the corrinoid-providing microorganisms in a community. This study provides systems-level information, i.e., taxonomic and functional compositions and dynamics of the supportive microorganisms in dechlorinating communities under different cobalamin conditions. The findings shed light on the important roles of Veillonellaceae species in the communities compared to other coexisting community members in producing and providing corrinoids for Dehalococcoides species under cobalamin-limited conditions. PMID:28188205

Molecular genetics of biosurfactant synthesis in microorganisms.

PubMed

Satpute, Surekha K; Bhuyan, Smita S; Pardesi, Karishma R; Mujumdar, Shilpa S; Dhakephalkar, Prashant K; Shete, Ashvini M; Chopade, Balu A

2010-01-01

Biosurfactant (BS)/bioemulsifier (BE) produced by varied microorganisms exemplify immense structural/functional diversity and consequently signify the involvement of particular molecular machinery in their biosynthesis. The present chapter aims to compile information on molecular genetics of BS/BE production in microorganisms. Polymer synthesis in Acinetobacter species is controlled by an intricate operon system and its further excretion being controlled by enzymes. Quorum sensing system (QSS) plays a fundamental role in rhamnolipid and surfactin synthesis. Depending upon the cell density, signal molecules (autoinducers) of regulatory pathways accomplish the biosynthesis of BS. The regulation of serrawettin production by Serratia is believed to be through non ribosomal peptide synthetases (NRPSs) and N-acylhomoserine lactones (AHLs) encoded by QSS located on mobile transposon. This regulation is under positive as well as negative control of QSS operon products. In case of yeast and fungi, glycolipid precursor production is catalyzed by genes that encode enzyme cytochrome P450 monooxygenase. BS/BE production is dictated by genes present on the chromosomes. This chapter also gives a glimpse of recent biotechnological developments which helped to realize molecular genetics of BS/BE production in microorganisms. Hyper-producing recombinants as well as mutant strains have been constructed successfully to improve the yield and quality of BS/BE. Thus promising biotechnological advances have expanded the applicability of BS/BE in therapeutics, cosmetics, agriculture, food, beverages and bioremediation etc. In brief, our knowledge on genetics of BS/BE production in prokaryotes is extensive as compared to yeast and fungi. Meticulous and concerted study will lead to an understanding of the molecular phenomena in unexplored microbes. In addition to this, recent promising advances will facilitate in broadening applications of BS/BE to diverse fields. Over the decades, valuable information on molecular genetics of BS/BE has been generated and this strong foundation would facilitate application oriented output of the surfactant industry and broaden its use in diverse fields. To accomplish our objectives, interaction among experts from diverse fields likes microbiology, physiology, biochemistry, molecular biology and genetics is indispensable.

Shell-vial culture and real-time PCR applied to Rickettsia typhi and Rickettsia felis detection.

PubMed

Segura, Ferran; Pons, Immaculada; Pla, Júlia; Nogueras, María-Mercedes

2015-11-01

Murine typhus is a zoonosis transmitted by fleas, whose etiological agent is Rickettsia typhi. Rickettsia felis infection can produces similar symptoms. Both are intracellular microorganisms. Therefore, their diagnosis is difficult and their infections can be misdiagnosed. Early diagnosis prevents severity and inappropriate treatment regimens. Serology can't be applied during the early stages of infection because it requires seroconversion. Shell-vial (SV) culture assay is a powerful tool to detect Rickettsia. The aim of the study was to optimize SV using a real-time PCR as monitoring method. Moreover, the study analyzes which antibiotics are useful to isolate these microorganisms from fleas avoiding contamination by other bacteria. For the first purpose, SVs were inoculated with each microorganism. They were incubated at different temperatures and monitored by real-time PCR and classical methods (Gimenez staining and indirect immunofluorescence assay). R. typhi grew at all temperatures. R. felis grew at 28 and 32 °C. Real-time PCR was more sensitive than classical methods and it detected microorganisms much earlier. Besides, the assay sensitivity was improved by increasing the number of SV. For the second purpose, microorganisms and fleas were incubated and monitored in different concentrations of antibiotics. Gentamicin, sufamethoxazole, trimethoprim were useful for R. typhi isolation. Gentamicin, streptomycin, penicillin, and amphotericin B were useful for R. felis isolation. Finally, the optimized conditions were used to isolate R. felis from fleas collected at a veterinary clinic. R. felis was isolated at 28 and 32 °C. However, successful establishment of cultures were not possible probably due to sub-optimal conditions of samples.

Effects of phosphate-solubilizing bacteria, native microorganisms, and rock dust on Jatropha curcas L. growth.

PubMed

Santana, E B; Marques, E L S; Dias, J C T

2016-10-05

Microorganisms with the ability to release nutrients to the soil from insoluble sources may be useful for plant cultivation. We evaluated the growth-promoting effect on Jatropha curcas L. of phosphate-solubilizing bacteria (PSB) and the native microbiota in soil with or without rock dust. J. curcas L. is important for biodiesel production. The experiments were performed in a greenhouse under a random-statistical design with 14 replicates. The soil received increasing dosages of rock dust. The presence of resident microorganisms and PSB inoculum was correlated with plant height, biomass production, and phosphorus content in plants for 120 days. Native soil microorganisms were detected and identified using denaturing gradient gel electrophoresis and DNA sequence analysis. Several bacterial populations belonged to the genus Bacillus. Populations associated with the phyla Chytridiomycota and Ascomycota were detected among the fungi. The best results for the variable plant height were correlated with the presence of resident microbiota and rock dust until the end of the experiment. The largest biomass production and the highest content of phosphorus occurred in the presence of soil-resident microbiota only up to 120 days. No significant effects were observed for biomass production with the use of PSB combined with rock dust. J. curcas L. under the influence of only resident microbiota showed the best plant growth results. Future research will focus on the specificity of resident microbiota activity in plant growth promotion and the isolation of these microorganisms to produce a new inoculum to be tested in various plants.

Isolation and enzyme bioprospection of endophytic bacteria associated with plants of Brazilian mangrove ecosystem.

PubMed

Castro, Renata A; Quecine, Maria Carolina; Lacava, Paulo T; Batista, Bruna D; Luvizotto, Danice M; Marcon, Joelma; Ferreira, Anderson; Melo, Itamar S; Azevedo, João L

2014-01-01

The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems.

Interference in adhesion of bacteria and yeasts isolated from explanted voice prostheses to silicone rubber by rhamnolipid biosurfactants.

PubMed

Rodrigues, L R; Banat, I M; van der Mei, H C; Teixeira, J A; Oliveira, R

2006-03-01

The effects and extent of adhesion of four different bacterial and two yeast strains isolated from explanted voice prostheses to silicone rubber with and without an adsorbed rhamnolipid biosurfactant layer obtained from Pseudomonasaeruginosa DS10-129 was studied. The ability of rhamnolipid biosurfactant to inhibit adhesion of micro-organisms to silicone rubber was investigated in a parallel-plate flow chamber. The anti-adhesive activity of the biosurfactant at different concentrations was significant against all the strains and depended on the micro-organism tested. The results showed an effective reduction in the initial deposition rates, and the number of bacterial cells adhering after 4 h, for all micro-organisms tested at the 4 g l(-1) undiluted rhamnolipid solution. Maximum initial reduction of adhesion rate (an average of 66%) occurred for Streptococcus salivarius GB 24/9 and Candida tropicalis GB 9/9. The number of cells adhering after 4 h on silicone rubber conditioned with biosurfactant was reduced to 48% for Staphylococcus epidermidis GB 9/6, Strep. salivarius GB 24/9, Staphylococcus aureus GB 2/1 and C. tropicalis GB 9/9 in comparison to controls. Perfusing the flow chamber with biosurfactant containing solution followed by the passage of a liquid-air interface, to investigate detachment of micro-organisms adhering to silicone rubber, produced high detachment (96%) of adhered cells for all micro-organisms studied, except for Staph. aureus GB 2/1 (67%). It is concluded that biosurfactant represent suitable compounds that should be considered in developing future strategies to prevent the microbial colonization of silicone rubber voice prostheses.