| characterization of a novel agrobacterium tumefaciens galactarolactone cycloisomerase enzyme for direct conversion of d-galactarolactone to 3-deoxy-2-keto-l-threo-hexarate. | microorganisms use different pathways for d-galacturonate catabolism. in the known microbial oxidative pathway, d-galacturonate is oxidized to d-galactarolactone, the lactone hydrolyzed to galactarate, which is further converted to 3-deoxy-2-keto-hexarate and α-ketoglutarate. we have shown recently that agrobacterium tumefaciens strain c58 contains an uronate dehydrogenase (at udh) that oxidizes d-galacturonic acid to d-galactarolactone. here we report identification of a novel enzyme from the s ... | 2012 | 22493433 |
| recent advances in petroleum microbiology. | recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. the physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. new molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystem ... | 2003 | 14665675 |
| current state and perspectives of producing biodiesel-like compounds by biotechnology. | the global demand for crude oil is expected to continue to rise in future while simultaneously oil production is currently reaching its peak. subsequently, rising oil prices and their negative impacts on economy, together with an increased environmental awareness of our society, directed the focus also on the biotechnological production of fuels. although a wide variety of such fuels has been suggested, only the production of ethanol and biodiesel has reached a certain economic feasibility and v ... | 2009 | 21255288 |
| aerobic cyanide degradation by bacterial isolates from cassava factory wastewater. | ten bacterial strains that utilize cyanide (cn) as a nitrogen source were isolated from cassava factory wastewater after enrichment in a liquid media containing sodium cyanide (1 mm) and glucose (0.2% w/v). the strains could tolerate and grow in cyanide concentrations of up to 5 mm. increased cyanide levels in the media caused an extension of lag phase in the bacterial growth indicating that they need some period of acclimatisation. the rate of cyanide removal by the strains depends on the initi ... | 2015 | 26413045 |
| cyanobacteria: photoautotrophic microbial factories for the sustainable synthesis of industrial products. | cyanobacteria are widely distributed gram-negative bacteria with a long evolutionary history and the only prokaryotes that perform plant-like oxygenic photosynthesis. cyanobacteria possess several advantages as hosts for biotechnological applications, including simple growth requirements, ease of genetic manipulation, and attractive platforms for carbon neutral production process. the use of photosynthetic cyanobacteria to directly convert carbon dioxide to biofuels is an emerging area of intere ... | 2015 | 26199945 |
| diversity and evolutionary analysis of iron-containing (type-iii) alcohol dehydrogenases in eukaryotes. | alcohol dehydrogenase (adh) activity is widely distributed in the three domains of life. currently, there are three non-homologous nad(p)+-dependent adh families reported: type i adh comprises zn-dependent adhs; type ii adh comprises short-chain adhs described first in drosophila; and, type iii adh comprises iron-containing adhs (feadhs). these three families arose independently throughout evolution and possess different structures and mechanisms of reaction. while types i and ii adhs have been ... | 2016 | 27893862 |
| determinants of cofactor specificity for the glucose-6-phosphate dehydrogenase from escherichia coli: simulation, kinetics and evolutionary studies. | glucose 6-phosphate dehydrogenases (g6pdhs) from different sources show varying specificities towards nad+ and nadp+ as cofactors. however, it is not known to what extent structural determinants of cofactor preference are conserved in the g6pdh family. in this work, molecular simulations, kinetic characterization of site-directed mutants and phylogenetic analyses were used to study the structural basis for the strong preference towards nadp+ shown by the g6pdh from escherichia coli. molecular dy ... | 2016 | 27010804 |
| biofilm reactors for industrial bioconversion processes: employing potential of enhanced reaction rates. | this article describes the use of biofilm reactors for the production of various chemicals by fermentation and wastewater treatment. biofilm formation is a natural process where microbial cells attach to the support (adsorbent) or form flocs/aggregates (also called granules) without use of chemicals and form thick layers of cells known as "biofilms." as a result of biofilm formation, cell densities in the reactor increase and cell concentrations as high as 74 gl(-1) can be achieved. the reactor ... | 2005 | 16122390 |
| snapshot of a reaction intermediate: analysis of benzoylformate decarboxylase in complex with a benzoylphosphonate inhibitor. | benzoylformate decarboxylase (bfdc) is a thiamin diphosphate- (thdp-) dependent enzyme acting on aromatic substrates. in addition to its metabolic role in the mandelate pathway, bfdc shows broad substrate specificity coupled with tight stereo control in the carbon-carbon bond-forming reverse reaction, making it a useful biocatalyst for the production of chiral alpha-hydroxy ketones. the reaction of methyl benzoylphosphonate (mbp), an analogue of the natural substrate benzoylformate, with bfdc re ... | 2009 | 19320438 |
| enzymatic deconstruction of xylan for biofuel production. | the combustion of fossil-derived fuels has a significant impact on atmospheric carbon dioxide (co(2)) levels and correspondingly is an important contributor to anthropogenic global climate change. plants have evolved photosynthetic mechanisms in which solar energy is used to fix co(2) into carbohydrates. thus, combustion of biofuels, derived from plant biomass, can be considered a potentially carbon neutral process. one of the major limitations for efficient conversion of plant biomass to biofue ... | 2009 | 20431716 |
| asymmetric bioreduction of activated alkenes to industrially relevant optically active compounds. | ene-reductases from the 'old yellow enzyme' family of flavoproteins catalyze the asymmetric reduction of various α,β-unsaturated compounds at the expense of a nicotinamide cofactor. they have been applied to the synthesis of valuable enantiopure products, including chiral building blocks with broad industrial applications, terpenoids, amino acid derivatives and fragrances. the combination of these highly stereoselective biocatalysts with a cofactor recycling system has allowed the development of ... | 2012 | 22498437 |
| challenges in enzymatic route of mannitol production. | mannitol is an important biochemical often used as medicine and in food sector, yet its biotechnological is not preffered in industry for large scale production, which may be due to the multistep mechanism involved in hydrogenation and reduction. this paper is a comparative preview covering present chemical and biotechnological approaches existing today for mannitol production at industrial scale. biotechnological routes are suitable for adaptation at industrial level for mannitol production, an ... | 2012 | 25969783 |
| challenges in enzymatic route of mannitol production. | mannitol is an important biochemical often used as medicine and in food sector, yet its biotechnological is not preffered in industry for large scale production, which may be due to the multistep mechanism involved in hydrogenation and reduction. this paper is a comparative preview covering present chemical and biotechnological approaches existing today for mannitol production at industrial scale. biotechnological routes are suitable for adaptation at industrial level for mannitol production, an ... | 2012 | 25969783 |
| functional characterization of the rna chaperone hfq in the opportunistic human pathogen stenotrophomonas maltophilia. | hfq is an rna-binding protein known to regulate a variety of cellular processes by interacting with small rnas (srnas) and mrnas in prokaryotes. stenotrophomonas maltophilia is an important opportunistic pathogen affecting primarily hospitalized and immunocompromised hosts. we constructed an hfq deletion mutant (δhfq) of s. maltophilia and compared the behaviors of wild-type and δhfq s. maltophilia cells in a variety of assays. this revealed that s. maltophilia hfq plays a role in biofilm format ... | 2012 | 22923593 |
| molecular characterization of an ice nucleation protein variant (inaq) from pseudomonas syringae and the analysis of its transmembrane transport activity in escherichia coli. | the ice nucleation protein (inp) of pseudomonas syringae has gained scientific interest not only because of its pathogenicity of foliar necroses but also for its wide range of potential applications, such as in snow making, frozen food preparation, and surface-display system development. however, studies on the transport activity of inp remain lacking. in the present study, a newly identified inp-gene variant, inaq, from a p. syringae mb03 strain was cloned. its structural domains, signal sequen ... | 2012 | 22991498 |
| synthetic biology of cyanobacteria: unique challenges and opportunities. | photosynthetic organisms, and especially cyanobacteria, hold great promise as sources of renewably-produced fuels, bulk and specialty chemicals, and nutritional products. synthetic biology tools can help unlock cyanobacteria's potential for these functions, but unfortunately tool development for these organisms has lagged behind that for s. cerevisiae and e. coli. while these organisms may in many cases be more difficult to work with as "chassis" strains for synthetic biology than certain hetero ... | 2013 | 24009604 |
| overcoming co-product inhibition in the nicotinamide independent asymmetric bioreduction of activated c=c-bonds using flavin-dependent ene-reductases. | eleven flavoproteins from the old yellow enzyme family were found to catalyze the disproportionation ("dismutation") of conjugated enones. incomplete conversions, which were attributed to enzyme inhibition by the co-product phenol could be circumvented via in situ co-product removal by scavenging the phenol using the polymeric adsorbent mp-carbonate. the optimized system allowed to reduce an alkene activated by ester groups in a "coupled-substrate" approach via nicotinamide-free hydrogen transfe ... | 2013 | 23794404 |
| glycolytic strategy as a tradeoff between energy yield and protein cost. | contrary to the textbook portrayal of glycolysis as a single pathway conserved across all domains of life, not all sugar-consuming organisms use the canonical embden-meyerhoff-parnass (emp) glycolytic pathway. prokaryotic glucose metabolism is particularly diverse, including several alternative glycolytic pathways, the most common of which is the entner-doudoroff (ed) pathway. the prevalence of the ed pathway is puzzling as it produces only one atp per glucose--half as much as the emp pathway. w ... | 2013 | 23630264 |
| discovery and characterization of a highly efficient enantioselective mandelonitrile hydrolase from burkholderia cenocepacia j2315 by phylogeny-based enzymatic substrate specificity prediction. | a nitrilase-mediated pathway has significant advantages in the production of optically pure (r)-(-)-mandelic acid. however, unwanted byproduct, low enantioselectivity, and specific activity reduce its value in practical applications. an ideal nitrilase that can efficiently hydrolyze mandelonitrile to optically pure (r)-(-)-mandelic acid without the unwanted byproduct is needed. | 2013 | 23414071 |
| the biology of habitat dominance; can microbes behave as weeds? | competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. these 'microbial weeds' are able to dominate the communities that develop in fertile ... | 2013 | 23336673 |
| exopolysaccharides produced by marine bacteria and their applications as glycosaminoglycan-like molecules. | although polysaccharides are ubiquitous and the most abundant renewable bio-components, their studies, covered by the glycochemistry and glycobiology fields, remain a challenge due to their high molecular diversity and complexity. polysaccharides are industrially used in food products; human therapeutics fall into a more recent research field and pharmaceutical industry is looking for more and more molecules with enhanced activities. glycosaminoglycans (gags) found in animal tissues play a criti ... | 2014 | 25340049 |
| synthetic biology devices for in vitro and in vivo diagnostics. | there is a growing need to enhance our capabilities in medical and environmental diagnostics. synthetic biologists have begun to focus their biomolecular engineering approaches toward this goal, offering promising results that could lead to the development of new classes of inexpensive, rapidly deployable diagnostics. many conventional diagnostics rely on antibody-based platforms that, although exquisitely sensitive, are slow and costly to generate and cannot readily confront rapidly emerging pa ... | 2015 | 26598662 |
| pseudomonas putida kt2440 strain metabolizes glucose through a cycle formed by enzymes of the entner-doudoroff, embden-meyerhof-parnas, and pentose phosphate pathways. | the soil bacterium pseudomonas putida kt2440 lacks a functional embden-meyerhof-parnas (emp) pathway, and glycolysis is known to proceed almost exclusively through the entner-doudoroff (ed) route. to investigate the raison d'être of this metabolic arrangement, the distribution of periplasmic and cytoplasmic carbon fluxes was studied in glucose cultures of this bacterium by using (13)c-labeled substrates, combined with quantitative physiology experiments, metabolite quantification, and in vitro e ... | 2015 | 26350459 |
| fluxome study of pseudomonas fluorescens reveals major reorganisation of carbon flux through central metabolic pathways in response to inactivation of the anti-sigma factor muca. | the bacterium pseudomonas fluorescens switches to an alginate-producing phenotype when the pleiotropic anti-sigma factor muca is inactivated. the inactivation is accompanied by an increased biomass yield on carbon sources when grown under nitrogen-limited chemostat conditions. a previous metabolome study showed significant changes in the intracellular metabolite concentrations, especially of the nucleotides, in muca deletion mutants compared to the wild-type. in this study, the p. fluorescens sb ... | 2015 | 25889900 |
| the mannitol utilization system of the marine bacterium zobellia galactanivorans. | mannitol is a polyol that occurs in a wide range of living organisms, where it fulfills different physiological roles. in particular, mannitol can account for as much as 20 to 30% of the dry weight of brown algae and is likely to be an important source of carbon for marine heterotrophic bacteria. zobellia galactanivorans (flavobacteriia) is a model for the study of pathways involved in the degradation of seaweed carbohydrates. annotation of its genome revealed the presence of genes potentially i ... | 2015 | 25548051 |
| building bridges: biocatalytic c-c-bond formation toward multifunctional products. | carbon-carbon bond formation is the key reaction for organic synthesis to construct the carbon framework of organic molecules. the review gives a selection of biocatalytic c-c-bond-forming reactions which have been investigated during the last 5 years and which have already been proven to be applicable for organic synthesis. in most cases, the reactions lead to products functionalized at the site of c-c-bond formation (e.g., α-hydroxy ketones, aminoalcohols, diols, 1,4-diketones, etc.) or allow ... | 2016 | 27398261 |
| global analysis of mannitol 2-dehydrogenase in lactobacillus reuteri crl 1101 during mannitol production through enzymatic, genetic and proteomic approaches. | several plants, fungi, algae, and certain bacteria produce mannitol, a polyol derived from fructose. mannitol has multiple industrial applications in the food, pharmaceutical, and medical industries, being mainly used as a non-metabolizable sweetener in foods. many heterofermentative lactic acid bacteria synthesize mannitol when an alternative electron acceptor such as fructose is present in the medium. in previous work, we reported the ability of lactobacillus reuteri crl 1101 to efficiently pr ... | 2017 | 28060932 |
| probing the substrate binding site of candida tenuis xylose reductase (akr2b5) with site-directed mutagenesis. | little is known about how substrates bind to ctxr (candida tenuis xylose reductase; akr2b5) and other members of the akr (aldo-keto reductase) protein superfamily. modelling of xylose into the active site of ctxr suggested that trp23, asp50 and asn309 are the main components of pentose-specific substrate-binding recognition. kinetic consequences of site-directed substitutions of these residues are reported. the mutants w23f and w23y catalysed nadh-dependent reduction of xylose with only 4 and 1% ... | 2005 | 16336198 |
| probing the substrate binding site of candida tenuis xylose reductase (akr2b5) with site-directed mutagenesis. | little is known about how substrates bind to ctxr (candida tenuis xylose reductase; akr2b5) and other members of the akr (aldo-keto reductase) protein superfamily. modelling of xylose into the active site of ctxr suggested that trp23, asp50 and asn309 are the main components of pentose-specific substrate-binding recognition. kinetic consequences of site-directed substitutions of these residues are reported. the mutants w23f and w23y catalysed nadh-dependent reduction of xylose with only 4 and 1% ... | 2005 | 16336198 |
| fluxome analysis using gc-ms. | fluxome analysis aims at the quantitative analysis of in vivo carbon fluxes in metabolic networks, i. e. intracellular activities of enzymes and pathways. it allows investigating the effects of genetic or environmental modifications and thus precisely provides a global perspective on the integrated genetic and metabolic regulation within the intact metabolic network. the experimental and computational approaches developed in this area have revealed fascinating insights into metabolic properties ... | 2007 | 17286851 |
| metabolic regulation and overproduction of primary metabolites. | 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 contri ... | 2008 | 21261849 |
| reanalysis of tyrannosaurus rex mass spectra. | asara et al. reported the detection of collagen peptides in a 68-million-year-old tyrannosaurus rex bone by shotgun proteomics. this finding has been called into question as a possible statistical artifact. we reanalyze asara et al.'s tandem mass spectra using a different search engine and different statistical tools. our reanalysis shows a sample containing common laboratory contaminants, soil bacteria, and bird-like hemoglobin and collagen. | 2009 | 19603827 |
| synthetic biology guides biofuel production. | the advancement of microbial processes for the production of renewable liquid fuels has increased with concerns about the current fuel economy. the development of advanced biofuels in particular has risen to address some of the shortcomings of ethanol. these advanced fuels have chemical properties similar to petroleum-based liquid fuels, thus removing the need for engine modification or infrastructure redesign. while the productivity and titers of each of these processes remains to be improved, ... | 2010 | 20827393 |
| nicotinamide-independent asymmetric bioreduction of cc-bonds via disproportionation of enones catalyzed by enoate reductases. | the asymmetric bioreduction of activated cc-bonds catalyzed by a single flavoprotein was achieved via direct hydrogen transfer from a sacrificial 2-enone or 1,4-dione as hydrogen donor without requirement of a nicotinamide cofactor. due to its simplicity, this system has clear advantages over conventional fad-recycling systems. | 2010 | 21270958 |
| engineering of a xylose metabolic pathway in rhodococcus strains. | the two metabolically versatile actinobacteria rhodococcus opacus pd630 and r. jostii rha1 can efficiently convert diverse organic substrates into neutral lipids mainly consisting of triacylglycerol (tag), the precursor of energy-rich hydrocarbon. neither, however, is able to utilize xylose, the important component present in lignocellulosic biomass, as the carbon source for growth and lipid accumulation. in order to broaden their substrate utilization range, the metabolic pathway of d-xylose ut ... | 2012 | 22636009 |
| increase in furfural tolerance in ethanologenic escherichia coli ly180 by plasmid-based expression of thya. | furfural is an inhibitory side product formed during the depolymerization of hemicellulose by mineral acids. genomic libraries from three different bacteria (bacillus subtilis yb886, escherichia coli nc3, and zymomonas mobilis cp4) were screened for genes that conferred furfural resistance on plates. beneficial plasmids containing the thya gene (coding for thymidylate synthase) were recovered from all three organisms. expression of this key gene in the de novo pathway for dtmp biosynthesis impro ... | 2012 | 22504824 |
| metabolic and regulatory rearrangements underlying efficient d-xylose utilization in engineered pseudomonas putida s12. | previously, an efficient d-xylose utilizing pseudomonas putida s12 strain was obtained by introducing the d-xylose isomerase pathway from escherichia coli, followed by evolutionary selection. in the present study, systemic changes associated with the evolved phenotype were identified by transcriptomics, enzyme activity analysis, and inverse engineering. a key element in improving the initially poor d-xylose utilization was the redistribution of 6-phospho-d-gluconate (6-pg) between the entner-dou ... | 2012 | 22416130 |
| biological denitrification of brine: the effect of compatible solutes on enzyme activities and fatty acid degradation. | the effect of the addition of compatible solutes (ectoine and trehalose) on the denitrification process of saline wastewater was studied. in saline wastewater, it was observed that the initial concentration of nitrates was 500 mg n l⁻¹. a fatty substance isolated from oiled bleaching earth (waste of vegetable oil refining process) was used as a source of carbon.the consortium, which was responsible for the denitrification process originated from the wastewater of the vegetable oil industry. the ... | 2012 | 22286267 |
| nad(p)h-independent asymmetric c=c bond reduction catalyzed by ene reductases by using artificial co-substrates as the hydrogen donor. | to develop a nicotinamide-independent single flavoenzyme system for the asymmetric bioreduction of c=c bonds, four types of hydrogen donor, encompassing more than 50 candidates, were investigated. six highly potent, cheap, and commercially available co-substrates were identified that (under the optimized conditions) resulted in conversions and enantioselectivities comparable with, or even superior to, those obtained with traditional two-enzyme nicotinamide adenine dinucleotide phosphate (nad(p)h ... | 2013 | 24382795 |
| nad(p)h-independent asymmetric c=c bond reduction catalyzed by ene reductases by using artificial co-substrates as the hydrogen donor. | to develop a nicotinamide-independent single flavoenzyme system for the asymmetric bioreduction of c=c bonds, four types of hydrogen donor, encompassing more than 50 candidates, were investigated. six highly potent, cheap, and commercially available co-substrates were identified that (under the optimized conditions) resulted in conversions and enantioselectivities comparable with, or even superior to, those obtained with traditional two-enzyme nicotinamide adenine dinucleotide phosphate (nad(p)h ... | 2013 | 24382795 |
| improving escherichia coli fuco for furfural tolerance by saturation mutagenesis of individual amino acid positions. | furfural is an inhibitory side product formed during the depolymerization of hemicellulose with mineral acids. in escherichia coli, furfural tolerance can be increased by expressing the native fuco gene (encoding lactaldehyde oxidoreductase). this enzyme also catalyzes the nadh-dependent reduction of furfural to the less toxic alcohol. saturation mutagenesis was combined with growth-based selection to isolate a mutated form of fuco that confers increased furfural tolerance. the mutation responsi ... | 2013 | 23475621 |
| chemoenzymatic asymmetric synthesis of pregabalin precursors via asymmetric bioreduction of β-cyanoacrylate esters using ene-reductases. | the asymmetric bioreduction of a library of β-cyanoacrylate esters using ene-reductases was studied with the aim to provide a biocatalytic route to precursors for gaba analogues, such as pregabalin. the stereochemical outcome could be controlled by substrate-engineering through size-variation of the ester moiety and by employing stereochemically pure (e)- or (z)-isomers, which allowed to access both enantiomers of each product in up to quantitative conversion in enantiomerically pure form. in ad ... | 2013 | 23316696 |
| production of fatty acid-derived valuable chemicals in synthetic microbes. | fatty acid derivatives, such as hydroxy fatty acids, fatty alcohols, fatty acid methyl/ethyl esters, and fatty alka(e)nes, have a wide range of industrial applications including plastics, lubricants, and fuels. currently, these chemicals are obtained mainly through chemical synthesis, which is complex and costly, and their availability from natural biological sources is extremely limited. metabolic engineering of microorganisms has provided a platform for effective production of these valuable b ... | 2014 | 25566540 |
| structure and functional characterization of pyruvate decarboxylase from gluconacetobacter diazotrophicus. | bacterial pyruvate decarboxylases (pdc) are rare. their role in ethanol production and in bacterially mediated ethanologenic processes has, however, ensured a continued and growing interest. pdcs from zymomonas mobilis (zmpdc), zymobacter palmae (zppdc) and sarcina ventriculi (svpdc) have been characterized and zmpdc has been produced successfully in a range of heterologous hosts. pdcs from the acetobacteraceae and their role in metabolism have not been characterized to the same extent. examples ... | 2014 | 25369873 |
| engineering escherichia coli to overproduce aromatic amino acids and derived compounds. | the production of aromatic amino acids using fermentation processes with recombinant microorganisms can be an advantageous approach to reach their global demands. in addition, a large array of compounds with alimentary and pharmaceutical applications can potentially be synthesized from intermediates of this metabolic pathway. however, contrary to other amino acids and primary metabolites, the artificial channelling of building blocks from central metabolism towards the aromatic amino acid pathwa ... | 2014 | 25200799 |
| butanol tolerance regulated by a two-component response regulator slr1037 in photosynthetic synechocystis sp. pcc 6803. | butanol production directly from co2 in photosynthetic cyanobacteria is restricted by the high toxicity of butanol to the hosts. in previous studies, we have found that a few two-component signal transduction systems (tcstss) were differentially regulated in synechocystis sp. pcc 6803 after butanol treatment. | 2014 | 24932218 |
| complete sequencing of novosphingobium sp. pp1y reveals a biotechnologically meaningful metabolic pattern. | novosphingobium sp. strain pp1y is a marine α-proteobacterium adapted to grow at the water/fuel oil interface. it exploits the aromatic fraction of fuel oils as a carbon and energy source. pp1y is able to grow on a wide range of mono-, poly- and heterocyclic aromatic hydrocarbons. here, we report the complete functional annotation of the whole novosphingobium genome. | 2014 | 24884518 |
| nitrile as activating group in the asymmetric bioreduction of β-cyanoacrylic acids catalyzed by ene-reductases. | asymmetric bioreduction of an (e)-β-cyano-2,4-dienoic acid derivative by ene-reductases allowed a shortened access to a precursor of pregabalin [(s)-3-(aminomethyl)-5-methylhexanoic acid] possessing the desired configuration in up to 94% conversion and >99% ee. deuterium labelling studies showed that the nitrile moiety was the preferred activating/anchor group in the active site of the enzyme over the carboxylic acid or the corresponding methyl ester. | 2014 | 26190962 |
| tolerance of anaerobic bacteria to chlorinated solvents. | the aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (cahs), perchloroethene (pce), carbon tetrachloride (ct), chloroform (cf) and 1,2-dichloroethane (1,2-dca), on the growth of eight anaerobic bacteria: four fermentative species (escherichia coli, klebsiella sp., clostridium sp. and paenibacillus sp.) and four respiring species (pseudomonas aeruginosa, geobacter sulfurreducens, shewanella oneidensis and desulfovibrio vulgaris). effective concentrations ... | 2014 | 24441515 |
| metabolic engineering and comparative performance studies of synechocystis sp. pcc 6803 strains for effective utilization of xylose. | wood sugars such as xylose can be used as an inexpensive carbon source for biotechnological applications. the model cyanobacterium synechocystis sp. pcc 6803 lacks the ability to catabolize wood sugars as an energy source. here, we generated four synechocystis strains that heterologously expressed xylab enzymes, which mediate xylose catabolism, either in combination with or without one of three xylose transporters, namely xyle, galp, or glf. except for glf, which is derived from the bacterium zy ... | 2015 | 26732758 |
| salt stress induced changes in the exoproteome of the halotolerant bacterium tistlia consotensis deciphered by proteogenomics. | the ability of bacteria to adapt to external osmotic changes is fundamental for their survival. halotolerant microorganisms, such as tistlia consotensis, have to cope with continuous fluctuations in the salinity of their natural environments which require effective adaptation strategies against salt stress. changes of extracellular protein profiles from tistlia consotensis in conditions of low and high salinities were monitored by proteogenomics using a bacterial draft genome. at low salinity, w ... | 2015 | 26287734 |
| a comparison of the microbial production and combustion characteristics of three alcohol biofuels: ethanol, 1-butanol, and 1-octanol. | over the last decade, microbes have been engineered for the manufacture of a variety of biofuels. saturated linear-chain alcohols have great potential as transport biofuels. their hydrocarbon backbones, as well as oxygenated content, confer combustive properties that make it suitable for use in internal combustion engines. herein, we compared the microbial production and combustion characteristics of ethanol, 1-butanol, and 1-octanol. in terms of productivity and efficiency, current microbial pl ... | 2015 | 26301219 |
| engineering sugar utilization and microbial tolerance toward lignocellulose conversion. | production of fuels and chemicals through a fermentation-based manufacturing process that uses renewable feedstock such as lignocellulosic biomass is a desirable alternative to petrochemicals. although it is still in its infancy, synthetic biology offers great potential to overcome the challenges associated with lignocellulose conversion. in this review, we will summarize the identification and optimization of synthetic biological parts used to enhance the utilization of lignocellulose-derived s ... | 2015 | 25741507 |
| unraveling the kinetic diversity of microbial 3-dehydroquinate dehydratases of shikimate pathway. | 3-dehydroquinate dehydratase (dhqase) catalyzes the conversion of 3-dehydroquinic acid to 3-dehydroshikimic acid of the shikimate pathway. in this study, 3180 prokaryotic genomes were examined and 459 dhqase sequences were retrieved. based on sequence analysis and their original hosts, 38 dhqase genes were selected for chemical synthesis. the selected dhqases were translated into new dna sequences according to the genetic codon usage bias by both escherichia coli and corynebacterium glutamicum. ... | 2015 | 25852984 |
| proof of concept for the simplified breakdown of cellulose by combining pseudomonas putida strains with surface displayed thermophilic endocellulase, exocellulase and β-glucosidase. | the production and employment of cellulases still represents an economic bottleneck in the conversion of lignocellulosic biomass to biofuels and other biocommodities. this process could be simplified by displaying the necessary enzymes on a microbial cell surface. such an approach, however, requires an appropriate host organism which on the one hand can withstand the rough environment coming along with lignocellulose hydrolysis, and on the other hand does not consume the generated glucose so tha ... | 2016 | 27287198 |
| high production of 3-hydroxypropionic acid in klebsiella pneumoniae by systematic optimization of glycerol metabolism. | 3-hydroxypropionic acid (3-hp) is an important platform chemical proposed by the united states department of energy. 3-hp can be converted to a series of bulk chemicals. biological production of 3-hp has made great progress in recent years. however, low yield of 3-hp restricts its commercialization. in this study, systematic optimization was conducted towards high-yield production of 3-hp in klebsiella pneumoniae. we first investigated appropriate promoters for the key enzyme (aldehyde dehydroge ... | 2016 | 27230116 |
| characterization of triclosan metabolism in sphingomonas sp. strain yl-jm2c. | triclosan (tcs) is one of the most widespread emerging contaminants and has adverse impact on aquatic ecosystem, yet little is known about its complete biodegradation mechanism in bacteria. sphingomonas sp, strain yl-jm2c, isolated from activated sludge of a wastewater treatment plant, was very effective on degrading tcs. response surface methodology (rsm) was applied to optimize the conditions like temperature and ph. from rsm, the optimal tcs degradation conditions were found to be 30 °c and p ... | 2016 | 26912101 |
| l-asparaginase production in the pseudomonas pseudoalcaligenes strain jhs-71 isolated from jooshan hot-spring. | l-asparaginase has lots of medical and industrial applications. ever since l-asparaginase anti-tumor activity was first demonstrated, its production using microbial systems has attracted considerable attention owing to their cost-effective and eco-friendly nature. the aim of this study is to obtain l-asparaginase producing bacteria and determining the enzyme activity. samples were picked up from jooshan hot springs located in the sirch, kerman. the l-asparaginase producing bacteria were screened ... | 2016 | 27844015 |
| cross-kingdom comparison of transcriptomic adjustments to low-oxygen stress highlights conserved and plant-specific responses. | high-throughput technology has facilitated genome-scale analyses of transcriptomic adjustments in response to environmental perturbations with an oxygen deprivation component, such as transient hypoxia or anoxia, root waterlogging, or complete submergence. we showed previously that arabidopsis (arabidopsis thaliana) seedlings elevate the levels of hundreds of transcripts, including a core group of 49 genes that are prioritized for translation across cell types of both shoots and roots. to recogn ... | 2010 | 20097791 |
| transposon and deletion mutagenesis of genes involved in perchlorate reduction in azospira suillum ps. | although much work on the biochemistry of the key enzymes of bacterial perchlorate reduction, chlorite dismutase, and perchlorate reductase has been published, understanding of the molecular mechanisms of this metabolism has been somewhat hampered by the lack of a clear model system amenable to genetic manipulation. using transposon mutagenesis and clean deletions, genes important for perchlorate reduction in azospira suillum ps have been identified both inside and outside the previously describ ... | 2013 | 24381299 |
| transposon and deletion mutagenesis of genes involved in perchlorate reduction in azospira suillum ps. | although much work on the biochemistry of the key enzymes of bacterial perchlorate reduction, chlorite dismutase, and perchlorate reductase has been published, understanding of the molecular mechanisms of this metabolism has been somewhat hampered by the lack of a clear model system amenable to genetic manipulation. using transposon mutagenesis and clean deletions, genes important for perchlorate reduction in azospira suillum ps have been identified both inside and outside the previously describ ... | 2013 | 24381299 |
| rapid quantification of mutant fitness in diverse bacteria by sequencing randomly bar-coded transposons. | transposon mutagenesis with next-generation sequencing (tnseq) is a powerful approach to annotate gene function in bacteria, but existing protocols for tnseq require laborious preparation of every sample before sequencing. thus, the existing protocols are not amenable to the throughput necessary to identify phenotypes and functions for the majority of genes in diverse bacteria. here, we present a method, random bar code transposon-site sequencing (rb-tnseq), which increases the throughput of mut ... | 2015 | 25968644 |
| application of synthetic biology in cyanobacteria and algae. | cyanobacteria and algae are becoming increasingly attractive cell factories for producing renewable biofuels and chemicals due to their ability to capture solar energy and co(2) and their relatively simple genetic background for genetic manipulation. increasing research efforts from the synthetic biology approach have been made in recent years to modify cyanobacteria and algae for various biotechnological applications. in this article, we critically review recent progresses in developing genetic ... | 2012 | 23049529 |
| genomic distribution and divergence of levansucrase-coding genes in pseudomonas syringae. | in the plant pathogenic bacterium, pseudomonas syringae, the exopolysaccharide levan is synthesized by extracellular levansucrase (lsc), which is encoded by two conserved 1,296-bp genes termed lscb and lscc in p. syringae strain pg4180. a third gene, lsca, is homologous to the 1,248-bp lsc gene of the bacterium erwinia amylovora, causing fire blight. however, lsca is not expressed in p. syringae strain pg4180. herein, pg4180 lsca was shown to be expressed from its native promoter in the lsc-defi ... | 2012 | 24704846 |
| challenges and advances in the heterologous expression of cellulolytic enzymes: a review. | second generation biofuel development is increasingly reliant on the recombinant expression of cellulases. designing or identifying successful expression systems is thus of preeminent importance to industrial progress in the field. recombinant production of cellulases has been performed using a wide range of expression systems in bacteria, yeasts and plants. in a number of these systems, particularly when using bacteria and plants, significant challenges have been experienced in expressing full- ... | 2014 | 25356086 |
| levan enhances associated growth of bacteroides, escherichia, streptococcus and faecalibacterium in fecal microbiota. | the role of dietary fiber in supporting healthy gut microbiota and overall well-being of the host has been revealed in several studies. here, we show the effect of a bacterial polyfructan levan on the growth dynamics and metabolism of fecal microbiota in vitro by using isothermal microcalorimetry. eleven fecal samples from healthy donors were incubated in phosphate-buffered defined medium with or without levan supplementation and varying presence of amino acids. the generation of heat, changes i ... | 2015 | 26629816 |
| bacterial clade with the ribosomal rna operon on a small plasmid rather than the chromosome. | rrna is essential for life because of its functional importance in protein synthesis. the rrna (rrn) operon encoding 16s, 23s, and 5s rrnas is located on the "main" chromosome in all bacteria documented to date and is frequently used as a marker of chromosomes. here, our genome analysis of a plant-associated alphaproteobacterium, aureimonas sp. au20, indicates that this strain has its sole rrn operon on a small (9.4 kb), high-copy-number replicon. we designated this unusual replicon carrying the ... | 2015 | 26534993 |
| comparative genomics of dna recombination and repair in cyanobacteria: biotechnological implications. | cyanobacteria are fascinating photosynthetic prokaryotes that are regarded as the ancestors of the plant chloroplast; the purveyors of oxygen and biomass for the food chain; and promising cell factories for an environmentally friendly production of chemicals. in colonizing most waters and soils of our planet, cyanobacteria are inevitably challenged by environmental stresses that generate dna damages. furthermore, many strains engineered for biotechnological purposes can use dna recombination to ... | 2016 | 27881980 |
| valorization of date palm (phoenix dactylifera) fruit processing by-products and wastes using bioprocess technology - review. | the date palm phoenix dactylifera has played an important role in the day-to-day life of the people for the last 7000 years. today worldwide production, utilization and industrialization of dates are continuously increasing since date fruits have earned great importance in human nutrition owing to their rich content of essential nutrients. tons of date palm fruit wastes are discarded daily by the date processing industries leading to environmental problems. wastes such as date pits represent an ... | 2013 | 23961227 |
| a novel type ii nad+-specific isocitrate dehydrogenase from the marine bacterium congregibacter litoralis kt71. | in most living organisms, isocitrate dehydrogenases (idhs) convert isocitrate into ɑ-ketoglutarate (ɑ-kg). phylogenetic analyses divide the idh protein family into two subgroups: types i and ii. based on cofactor usage, idhs are either nad+-specific (nad-idh) or nadp+-specific (nadp-idh); nadp-idh evolved from nad-idh. type i idhs include nad-idhs and nadp-idhs; however, no type ii nad-idhs have been reported to date. this study reports a novel type ii nad-idh from the marine bacterium congregib ... | 2015 | 25942017 |
| bridges and chasms: summary of the image 2 meeting in montreal, canada, 30 april to 3 may 2007. | | 2007 | 17827302 |
| bridges and chasms: summary of the image 2 meeting in montreal, canada, 30 april to 3 may 2007. | | 2007 | 17827302 |
| the cytochrome bd respiratory oxygen reductases. | cytochrome bd is a respiratory quinol: o₂ oxidoreductase found in many prokaryotes, including a number of pathogens. the main bioenergetic function of the enzyme is the production of a proton motive force by the vectorial charge transfer of protons. the sequences of cytochromes bd are not homologous to those of the other respiratory oxygen reductases, i.e., the heme-copper oxygen reductases or alternative oxidases (aox). generally, cytochromes bd are noteworthy for their high affinity for o₂ and ... | 2011 | 21756872 |
| a survey of oxidative paracatalytic reactions catalyzed by enzymes that generate carbanionic intermediates: implications for ros production, cancer etiology, and neurodegenerative diseases. | | 2011 | 21692372 |
| pyruvate decarboxylase provides growing pollen tubes with a competitive advantage in petunia. | rapid pollen tube growth places unique demands on energy production and biosynthetic capacity. the aim of this work is to understand how primary metabolism meets the demands of such rapid growth. aerobically grown pollen produce ethanol in large quantities. the ethanolic fermentation pathway consists of two committed enzymes: pyruvate decarboxylase (pdc) and alcohol dehydrogenase (adh). because adh mutations do not affect male gametophyte function, the obvious question is why pollen synthesize a ... | 2005 | 15994907 |
| origins of flagellar gene operons and secondary flagellar systems. | forty-one flagellated species representing 11 bacterial phyla were used to investigate the origin of secondary flagellar systems and the structure and formation of flagellar gene operons over the course of bacterial evolution. secondary (i.e., lateral) flagellar systems, which are harbored by five of the proteobacterial species considered, originated twice, once in the alphaproteobacterial lineage and again in the common ancestor of the beta- and gammaproteobacteria. the order and organization o ... | 2007 | 17644605 |
| sites inferred by metabolic background assertion labeling (simbal): adapting the partial phylogenetic profiling algorithm to scan sequences for signatures that predict protein function. | comparative genomics methods such as phylogenetic profiling can mine powerful inferences from inherently noisy biological data sets. we introduce sites inferred by metabolic background assertion labeling (simbal), a method that applies the partial phylogenetic profiling (ppp) approach locally within a protein sequence to discover short sequence signatures associated with functional sites. the approach is based on the basic scoring mechanism employed by ppp, namely the use of binomial distributio ... | 2010 | 20102603 |
| quantitative hopanoid analysis enables robust pattern detection and comparison between laboratories. | hopanoids are steroid-like lipids from the isoprenoid family that are produced primarily by bacteria. hopanes, molecular fossils of hopanoids, offer the potential to provide insight into environmental transitions on the early earth, if their sources and biological functions can be constrained. semiquantitative methods for mass spectrometric analysis of hopanoids from cultures and environmental samples have been developed in the last two decades. however, the structural diversity of hopanoids, an ... | 2015 | 25865768 |
| a comprehensive genomic, transcriptomic and proteomic analysis of a hyperosmotic stress sensitive α-proteobacterium. | with the aim of remaining viable, bacteria must deal with changes in environmental conditions, including increases in external osmolarity. while studies concerning bacterial response to this stress condition have focused on soil, marine and enteric species, this report is about caulobacter crescentus, a species inhabiting freshwater oligotrophic habitats. | 2015 | 25879753 |
| the evolution of function in strictosidine synthase-like proteins. | the exponential growth of sequence data provides abundant information for the discovery of new enzyme reactions. correctly annotating the functions of highly diverse proteins can be difficult, however, hindering use of this information. global analysis of large superfamilies of related proteins is a powerful strategy for understanding the evolution of reactions by identifying catalytic commonalities and differences in reaction and substrate specificity, even when only a few members have been bio ... | 2011 | 21948213 |
| three different classes of aminotransferases evolved prephenate aminotransferase functionality in arogenate-competent microorganisms. | the aromatic amino acids phenylalanine and tyrosine represent essential sources of high value natural aromatic compounds for human health and industry. depending on the organism, alternative routes exist for their synthesis. phenylalanine and tyrosine are synthesized either via phenylpyruvate/4-hydroxyphenylpyruvate or via arogenate. in arogenate-competent microorganisms, an aminotransferase is required for the transamination of prephenate into arogenate, but the identity of the genes is still u ... | 2013 | 24302739 |
| three different classes of aminotransferases evolved prephenate aminotransferase functionality in arogenate-competent microorganisms. | the aromatic amino acids phenylalanine and tyrosine represent essential sources of high value natural aromatic compounds for human health and industry. depending on the organism, alternative routes exist for their synthesis. phenylalanine and tyrosine are synthesized either via phenylpyruvate/4-hydroxyphenylpyruvate or via arogenate. in arogenate-competent microorganisms, an aminotransferase is required for the transamination of prephenate into arogenate, but the identity of the genes is still u ... | 2013 | 24302739 |
| the structure of substrate-free 1,5-anhydro-d-fructose reductase from sinorhizobium meliloti 1021 reveals an open enzyme conformation. | 1,5-anhydro-d-fructose (1,5-af) is an interesting building block for enantioselective and stereoselective organic synthesis. enzymes acting on this compound are potential targets for structure-based protein/enzyme design to extend the repertoire of catalytic modifications of this and related building blocks. recombinant 1,5-anhydro-d-fructose reductase (afr) from sinorhizobium meliloti 1021 was produced in escherichia coli, purified using a fused 6×his affinity tag and crystallized in complex wi ... | 2013 | 23908025 |
| utilization of d-ribitol by lactobacillus casei bl23 requires a mannose-type phosphotransferase system and three catabolic enzymes. | lactobacillus casei strains 64h and bl23, but not atcc 334, are able to ferment d-ribitol (also called d-adonitol). however, a bl23-derived ptsi mutant lacking enzyme i of the phosphoenolpyruvate:carbohydrate phosphotransferase system (pts) was not able to utilize this pentitol, suggesting that strain bl23 transports and phosphorylates d-ribitol via a pts. we identified an 11-kb region in the genome sequence of l. casei strain bl23 (lcabl_29160 to lcabl_29270) which is absent from strain atcc 33 ... | 2013 | 23564164 |
| combined fluxomics and transcriptomics analysis of glucose catabolism via a partially cyclic pentose phosphate pathway in gluconobacter oxydans 621h. | in this study, the distribution and regulation of periplasmic and cytoplasmic carbon fluxes in gluconobacter oxydans 621h with glucose were studied by (13)c-based metabolic flux analysis ((13)c-mfa) in combination with transcriptomics and enzyme assays. for (13)c-mfa, cells were cultivated with specifically (13)c-labeled glucose, and intracellular metabolites were analyzed for their labeling pattern by liquid chromatography-mass spectrometry (lc-ms). in growth phase i, 90% of the glucose was oxi ... | 2013 | 23377928 |
| analysis of a taurine-dependent promoter in sinorhizobium meliloti that offers tight modulation of gene expression. | genetic models have been developed in divergent branches of the class alphaproteobacteria to help answer a wide spectrum of questions regarding bacterial physiology. for example, sinorhizobium meliloti serves as a useful representative for investigating rhizobia-plant symbiosis and nitrogen fixation, caulobacter crescentus for studying cell cycle regulation and organelle biogenesis, and zymomonas mobilis for assessing the potentials of metabolic engineering and biofuel production. a tightly regu ... | 2014 | 25420869 |
| phenolic amides are potent inhibitors of de novo nucleotide biosynthesis. | an outstanding challenge toward efficient production of biofuels and value-added chemicals from plant biomass is the impact that lignocellulose-derived inhibitors have on microbial fermentations. elucidating the mechanisms that underlie their toxicity is critical for developing strategies to overcome them. here, using escherichia coli as a model system, we investigated the metabolic effects and toxicity mechanisms of feruloyl amide and coumaroyl amide, the predominant phenolic compounds in ammon ... | 2015 | 26070680 |
| global metabolic responses to salt stress in fifteen species. | cells constantly adapt to unpredictably changing extracellular solute concentrations. a cornerstone of the cellular osmotic stress response is the metabolic supply of energy and building blocks to mount appropriate defenses. yet, the extent to which osmotic stress impinges on the metabolic network remains largely unknown. moreover, it is mostly unclear which, if any, of the metabolic responses to osmotic stress are conserved among diverse organisms or confined to particular groups of species. he ... | 2016 | 26848578 |
| molecular and biochemical characterization of entamoeba histolytica fructokinase. | entamoeba histolytica is the causative agent of amoebic dysentery and liver abscess. the medium for its axenic culture contains glucose as energy source, and we addressed the question whether e. histolytica can also use fructose instead. as the amoebic hexokinases do not phosphorylate fructose, a separate fructokinase is essential. the genome project revealed a single candidate gene encoding an e. histolytica homolog of bacterial fructokinases. this gene was cloned, and the recombinant enzyme ha ... | 2015 | 25700717 |
| ribosylhopane, a novel bacterial hopanoid, as precursor of c35 bacteriohopanepolyols in streptomyces coelicolor a3(2). | wild-type streptomyces coelicolor a3(2) produces aminobacteriohopanetriol as the only elongated c35 hopanoid. the hopanoid phenotype of two mutants bearing a deletion of genes from a previously identified hopanoid biosynthesis gene cluster provides clues to the formation of c35 bacteriohopanepolyols. orf14 encodes a putative nucleosidase; its deletion induces the accumulation of adenosylhopane as it cannot be converted into ribosylhopane. orf18 encodes a putative transaminase; its deletion resul ... | 2014 | 25155017 |
| discovery, taxonomic distribution, and phenotypic characterization of a gene required for 3-methylhopanoid production. | hopanoids methylated at the c-3 position are a subset of bacterial triterpenoids that are readily preserved in modern and ancient sediments and in petroleum. the production of 3-methylhopanoids by extant aerobic methanotrophs and their common occurrence in modern and fossil methane seep communities, in conjunction with carbon isotope analysis, has led to their use as biomarker proxies for aerobic methanotrophy. in addition, these lipids are also produced by aerobic acetic acid bacteria and, lack ... | 2012 | 22826256 |
| isocitrate dehydrogenase from streptococcus mutans: biochemical properties and evaluation of a putative phosphorylation site at ser102. | isocitrate deyhdrogenase (idh) is a reversible enzyme in the tricarboxylic acid cycle that catalyzes the nad(p)(+)-dependent oxidative decarboxylation of isocitrate to α-ketoglutarate (αkg) and the nad(p)h/co2-dependent reductive carboxylation of αkg to isocitrate. the idh gene from streptococcus mutans was fused with the icd gene promoter from escherichia coli to initiate its expression in the glutamate auxotrophic strain e. coli δicd::kan(r) of which the icd gene has been replaced by kanamycin ... | 2013 | 23484056 |
| biosynthesis of squalene from farnesyl diphosphate in bacteria: three steps catalyzed by three enzymes. | squalene (sq) is an intermediate in the biosynthesis of sterols in eukaryotes and a few bacteria and of hopanoids in bacteria where they promote membrane stability and the formation of lipid rafts in their hosts. the genes for hopanoid biosynthesis are typically located on clusters that consist of four highly conserved genes-hpnc, hpnd, hpne, and hpnf-for conversion of farnesyl diphosphate (fpp) to hopene or related pentacyclic metabolites. while hpnf is known to encode a squalene cyclase, the f ... | 2015 | 26258173 |
| the future of butyric acid in industry. | in this paper, the different applications of butyric acid and its current and future production status are highlighted, with a particular emphasis on the biofuels industry. as such, this paper discusses different issues regarding butyric acid fermentations and provides suggestions for future improvements and their approaches. | 2012 | 22593687 |
| the microbiology of malting and brewing. | brewing beer involves microbial activity at every stage, from raw material production and malting to stability in the package. most of these activities are desirable, as beer is the result of a traditional food fermentation, but others represent threats to the quality of the final product and must be controlled actively through careful management, the daily task of maltsters and brewers globally. this review collates current knowledge relevant to the biology of brewing yeast, fermentation manage ... | 2013 | 23699253 |
| pulque, a traditional mexican alcoholic fermented beverage: historical, microbiological, and technical aspects. | pulque is a traditional mexican alcoholic beverage produced from the fermentation of the fresh sap known as aguamiel (mead) extracted from several species of agave (maguey) plants that grow in the central mexico plateau. currently, pulque is produced, sold and consumed in popular districts of mexico city and rural areas. the fermented product is a milky white, viscous, and slightly acidic liquid beverage with an alcohol content between 4 and 7° gl and history of consumption that dates back to pr ... | 2016 | 27446061 |
| functional properties of microorganisms in fermented foods. | fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. the present paper is aimed to review the information on some fu ... | 2016 | 27199913 |
| the phytohormone ethylene enhances cellulose production, regulates crp/fnrkx transcription and causes differential gene expression within the bacterial cellulose synthesis operon of komagataeibacter (gluconacetobacter) xylinus atcc 53582. | komagataeibacter (formerly gluconacetobacter) xylinus atcc 53582 is a plant-associated model organism for bacterial cellulose (bc) biosynthesis. this bacterium inhabits the carposphere where it interacts with fruit through the bi-directional transfer of phytohormones. the majority of research regarding k. xylinus has been focused on identifying and characterizing structural and regulatory factors that control bc biosynthesis, but its ecophysiology has been generally overlooked. ethylene is a phy ... | 2015 | 26733991 |
| crystal structure of pyruvate decarboxylase from zymobacter palmae. | pyruvate decarboxylase (pdc; ec 4.1.1.1) is a thiamine pyrophosphate- and mg(2+) ion-dependent enzyme that catalyses the non-oxidative decarboxylation of pyruvate to acetaldehyde and carbon dioxide. it is rare in bacteria, but is a key enzyme in homofermentative metabolism, where ethanol is the major product. here, the previously unreported crystal structure of the bacterial pyruvate decarboxylase from zymobacter palmae is presented. the crystals were shown to diffract to 2.15 å resolution. they ... | 2016 | 27599861 |
| biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste. | the considerable increase in biodiesel production worldwide in the last 5 years resulted in a stoichiometric increased coproduction of crude glycerol. as an excess of crude glycerol has been produced, its value on market was reduced and it is becoming a "waste-stream" instead of a valuable "coproduct". the development of biorefineries, i.e. production of chemicals and power integrated with conversion processes of biomass into biofuels, has been singled out as a way to achieve economically viable ... | 2012 | 22809320 |