| genome-based comparative analyses of antarctic and temperate species of paenibacillus. | antarctic soils represent a unique environment characterised by extremes of temperature, salinity, elevated uv radiation, low nutrient and low water content. despite the harshness of this environment, members of 15 bacterial phyla have been identified in soils of the ross sea region (rsr). however, the survival mechanisms and ecological roles of these phyla are largely unknown. the aim of this study was to investigate whether strains of paenibacillus darwinianus owe their resilience to substanti ... | 2014 | 25285990 |
| identification of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid in steroid degradation by comamonas testosteroni ta441 and its conversion to the corresponding 6-en-5-oyl coenzyme a (coa) involving open reading frame 28 (orf28)- and orf30-encoded acyl-coa dehydrogenases. | comamonas testosteroni ta441 degrades steroids via aromatization and meta-cleavage of the a ring, followed by hydrolysis, and produces 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid as an intermediate compound. herein, we identify a new intermediate compound, 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid. open reading frame 28 (orf28)- and orf30-encoded acyl coenzyme a (acyl-coa) dehydrogenase was shown to convert the coa ester of 9α-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandros ... | 2014 | 25092028 |
| generalist hydrocarbon-degrading bacterial communities in the oil-polluted water column of the north sea. | the aim of this work was to determine the effect of light crude oil on bacterial communities during an experimental oil spill in the north sea and in mesocosms (simulating a heavy, enclosed oil spill), and to isolate and characterize hydrocarbon-degrading bacteria from the water column. no oil-induced changes in bacterial community (3 m below the sea surface) were observed 32 h after the experimental spill at sea. in contrast, there was a decrease in the dominant sar11 phylotype and an increase ... | 2014 | 25251384 |
| generalist hydrocarbon-degrading bacterial communities in the oil-polluted water column of the north sea. | the aim of this work was to determine the effect of light crude oil on bacterial communities during an experimental oil spill in the north sea and in mesocosms (simulating a heavy, enclosed oil spill), and to isolate and characterize hydrocarbon-degrading bacteria from the water column. no oil-induced changes in bacterial community (3 m below the sea surface) were observed 32 h after the experimental spill at sea. in contrast, there was a decrease in the dominant sar11 phylotype and an increase ... | 2014 | 25251384 |
| desferrithiocin: a search for clinically effective iron chelators. | the successful search for orally active iron chelators to treat transfusional iron-overload diseases, e.g., thalassemia, is overviewed. the critical role of iron in nature as a redox engine is first described, as well as how primitive life forms and humans manage the metal. the problems that derive when iron homeostasis in humans is disrupted and the mechanism of the ensuing damage, uncontrolled fenton chemistry, are discussed. the solution to the problem, chelator-mediated iron removal, is clea ... | 2014 | 25207964 |
| cheese rind communities provide tractable systems for in situ and in vitro studies of microbial diversity. | tractable microbial communities are needed to bridge the gap between observations of patterns of microbial diversity and mechanisms that can explain these patterns. we developed cheese rinds as model microbial communities by characterizing in situ patterns of diversity and by developing an in vitro system for community reconstruction. sequencing of 137 different rind communities across 10 countries revealed 24 widely distributed and culturable genera of bacteria and fungi as dominant community m ... | 2014 | 25036636 |
| stability curve prediction of homologous proteins using temperature-dependent statistical potentials. | the unraveling and control of protein stability at different temperatures is a fundamental problem in biophysics that is substantially far from being quantitatively and accurately solved, as it requires a precise knowledge of the temperature dependence of amino acid interactions. in this paper we attempt to gain insight into the thermal stability of proteins by designing a tool to predict the full stability curve as a function of the temperature for a set of 45 proteins belonging to 11 homologou ... | 2014 | 25032839 |
| endotoxin structures in the psychrophiles psychromonas marina and psychrobacter cryohalolentis contain distinctive acyl features. | lipid a is the essential component of endotoxin (gram-negative lipopolysaccharide), a potent immunostimulatory compound. as the outer surface of the outer membrane, the details of lipid a structure are crucial not only to bacterial pathogenesis but also to membrane integrity. this work characterizes the structure of lipid a in two psychrophiles, psychromonas marina and psychrobacter cryohalolentis, and also two mesophiles to which they are related using maldi-tof ms and fatty acid methyl ester ( ... | 2014 | 25010385 |
| cloning, expression, purification, and characterization of glutaredoxin from antarctic sea-ice bacterium pseudoalteromonas sp. an178. | glutaredoxins (grxs) are small ubiquitous redox enzymes that catalyze glutathione-dependent reactions to reduce protein disulfide. in this study, a full-length grx gene (psgrx) with 270 nucleotides was isolated from antarctic sea-ice bacterium pseudoalteromonas sp. an178. it encoded deduced 89 amino acid residues with the molecular weight 9.8 kda. sequence analysis of the amino acid sequence revealed the catalytic motif cpyc. recombinant psgrx (rpsgrx) stably expressed in e. coli bl21 was purifi ... | 2014 | 25110664 |
| marker for type vi secretion system effectors. | bacteria use diverse mechanisms to kill, manipulate, and compete with other cells. the recently discovered type vi secretion system (t6ss) is widespread in bacterial pathogens and used to deliver virulence effector proteins into target cells. using comparative proteomics, we identified two previously unidentified t6ss effectors that contained a conserved motif. bioinformatic analyses revealed that this n-terminal motif, named mix (marker for type six effectors), is found in numerous polymorphic ... | 2014 | 24927539 |
| brine assemblages of ultrasmall microbial cells within the ice cover of lake vida, antarctica. | the anoxic and freezing brine that permeates lake vida's perennial ice below 16 m contains an abundance of very small (≤0.2-μm) particles mixed with a less abundant population of microbial cells ranging from >0.2 to 1.5 μm in length. fluorescent dna staining, electron microscopy (em) observations, elemental analysis, and extraction of high-molecular-weight genomic dna indicated that a significant portion of these ultrasmall particles are cells. a continuous electron-dense layer surrounding a les ... | 2014 | 24727273 |
| fermentation technologies for the optimization of marine microbial exopolysaccharide production. | in the last decades, research has focused on the capabilities of microbes to secrete exopolysaccharides (eps), because these polymers differ from the commercial ones derived essentially from plants or algae in their numerous valuable qualities. these biopolymers have emerged as new polymeric materials with novel and unique physical characteristics that have found extensive applications. in marine microorganisms the produced eps provide an instrument to survive in adverse conditions: they are fou ... | 2014 | 24857960 |
| marine microbial metagenomics: from individual to the environment. | microbes are the most abundant biological entities on earth, therefore, studying them is important for understanding their roles in global ecology. the science of metagenomics is a relatively young field of research that has enjoyed significant effort since its inception in 1998. studies using next-generation sequencing techniques on single genomes and collections of genomes have not only led to novel insights into microbial genomics, but also revealed a close association between environmental n ... | 2014 | 24857918 |
| nitrite-reductase and peroxynitrite isomerization activities of methanosarcina acetivorans protoglobin. | within the globin superfamily, protoglobins (pgb) belong phylogenetically to the same cluster of two-domain globin-coupled sensors and single-domain sensor globins. multiple functional roles have been postulated for methanosarcina acetivorans pgb (ma-pgb), since the detoxification of reactive nitrogen and oxygen species might co-exist with enzymatic activity(ies) to facilitate the conversion of co to methane. here, the nitrite-reductase and peroxynitrite isomerization activities of the cyse20ser ... | 2014 | 24827820 |
| optimization of amylase production from b. amyloliquefaciens (mtcc 1270) using solid state fermentation. | demand for microbial amylase production persists because of its immense importance in wide spectrum industries. the present work has been initiated with a goal of optimization of solid state fermentation condition for amylase using agroindustrial waste and microbial strain like b. amyloliquefaciens (mtcc 1270). in an aim to improve the productivity of amylase, fermentation has been carried out in the presence of calcium (ca(+2)), nitrate (no3 (-)), and chloride ions (cl(-)) as well as in the pre ... | 2014 | 24949017 |
| characterization of single-stranded dna-binding proteins from the psychrophilic bacteria desulfotalea psychrophila, flavobacterium psychrophilum, psychrobacter arcticus, psychrobacter cryohalolentis, psychromonas ingrahamii, psychroflexus torquis, and photobacterium profundum. | single-stranded dna-binding proteins (ssbs) play essential roles in dna replication, recombination and repair in bacteria, archaea and eukarya. in recent years, there has been an increasing interest in ssbs, since they find numerous applications in diverse molecular biology and analytical methods. | 2014 | 24725436 |
| characterization of the vibrio cholerae vola surface-exposed lipoprotein lysophospholipase. | bacterial lipases play important roles in bacterial metabolism and environmental response. our laboratory recently discovered that a novel lipoprotein lysophospholipase, vola, localizes on the surface of the gram-negative aquatic pathogen vibrio cholerae. vola functions to cleave exogenous lysophosphatidylcholine, freeing the fatty acid moiety for use by v. cholerae. this fatty acid is transported into the cell and can be used as a nutrient and, more importantly, as a way to alter the membrane a ... | 2014 | 24532770 |
| some like it cold: understanding the survival strategies of psychrophiles. | much of the earth's surface, both marine and terrestrial, is either periodically or permanently cold. although habitats that are largely or continuously frozen are generally considered to be inhospitable to life, psychrophilic organisms have managed to survive in these environments. this is attributed to their innate adaptive capacity to cope with cold and its associated stresses. here, we review the various environmental, physiological and molecular adaptations that psychrophilic microorganisms ... | 2014 | 24671034 |
| rna-seq-based analysis of cold shock response in thermoanaerobacter tengcongensis, a bacterium harboring a single cold shock protein encoding gene. | although cold shock responses and the roles of cold shock proteins in microorganisms containing multiple cold shock protein genes have been well characterized, related studies on bacteria possessing a single cold shock protein gene have not been reported. thermoanaerobacter tengcongensis mb4, a thermophile harboring only one known cold shock protein gene (ttescpc), can survive from 50° to 80 °c, but has poor natural competence under cold shock at 50 °c. we therefore examined cold shock responses ... | 2014 | 24667527 |
| actinobacterial acyl coenzyme a synthetases involved in steroid side-chain catabolism. | bacterial steroid catabolism is an important component of the global carbon cycle and has applications in drug synthesis. pathways for this catabolism involve multiple acyl coenzyme a (coa) synthetases, which activate alkanoate substituents for β-oxidation. the functions of these synthetases are poorly understood. we enzymatically characterized four distinct acyl-coa synthetases from the cholate catabolic pathway of rhodococcus jostii rha1 and the cholesterol catabolic pathway of mycobacterium t ... | 2014 | 24244004 |
| development of a genetic system for the deep-sea psychrophilic bacterium pseudoalteromonas sp. sm9913. | pseudoalteromonas species are a group of marine gammaproteobacteria frequently found in deep-sea sediments, which may play important roles in deep-sea sediment ecosystem. although genome sequence analysis of pseudoalteromonas has revealed some specific features associated with adaptation to the extreme deep-sea environment, it is still difficult to study how pseudoalteromonas adapt to the deep-sea environment due to the lack of a genetic manipulation system. the aim of this study is to develop a ... | 2014 | 24450434 |
| identification, cloning, and expression of l-amino acid oxidase from marine pseudoalteromonas sp. b3. | l-amino acid oxidase (laao) is attracting more attentions due to its broad and important biological functions. recently, an laao-producing marine microorganism (strain b3) was isolated from the intertidal zone of dinghai sea area, china. physiological, biochemical, and molecular identifications together with phylogenetic analysis congruously suggested that it belonged to the genus pseudoalteromonas. therefore, it was designated as pseudoalteromonas sp. b3. its capability of laao production was c ... | 2014 | 24526926 |
| engineering low-temperature expression systems for heterologous production of cold-adapted enzymes. | production of psychrophilic enzymes in the commonly used mesophilic expression systems is hampered by low intrinsic stability of the recombinant enzymes at the optimal host growth temperatures. unless strategies for low-temperature expression are advanced, research on psychrophilic enzymes may end up being biased toward those that can be stably produced in commonly used mesophilic host systems. two main strategies are currently being explored for the development of low-temperature expression in ... | 2015 | 26710170 |
| engineering low-temperature expression systems for heterologous production of cold-adapted enzymes. | production of psychrophilic enzymes in the commonly used mesophilic expression systems is hampered by low intrinsic stability of the recombinant enzymes at the optimal host growth temperatures. unless strategies for low-temperature expression are advanced, research on psychrophilic enzymes may end up being biased toward those that can be stably produced in commonly used mesophilic host systems. two main strategies are currently being explored for the development of low-temperature expression in ... | 2015 | 26710170 |
| systems biology of microbial exopolysaccharides production. | exopolysaccharides (epss) produced by diverse group of microbial systems are rapidly emerging as new and industrially important biomaterials. due to their unique and complex chemical structures and many interesting physicochemical and rheological properties with novel functionality, the microbial epss find wide range of commercial applications in various fields of the economy such as food, feed, packaging, chemical, textile, cosmetics and pharmaceutical industry, agriculture, and medicine. epss ... | 2015 | 26734603 |
| novel essential role of ethanol oxidation genes at low temperature revealed by transcriptome analysis in the antarctic bacterium pseudomonas extremaustralis. | temperature is one of the most important factors for bacterial growth and development. cold environments are widely distributed on earth, and psychrotolerant and psychrophilic microorganisms have developed different adaptation strategies to cope with the stress derived from low temperatures. pseudomonas extremaustralis is an antarctic bacterium able to grow under low temperatures and to produce high amounts of polyhydroxyalkanoates (phas). in this work, we analyzed the genome-wide transcriptome ... | 2015 | 26671564 |
| anti-biofilm activities from marine cold adapted bacteria against staphylococci and pseudomonas aeruginosa. | microbial biofilms have great negative impacts on the world's economy and pose serious problems to industry, public health and medicine. the interest in the development of new approaches for the prevention and treatment of bacterial adhesion and biofilm formation has increased. since, bacterial pathogens living in biofilm induce persistent chronic infections due to the resistance to antibiotics and host immune system. a viable approach should target adhesive properties without affecting bacteria ... | 2015 | 26696962 |
| bimodal rheotactic behavior reflects flagellar beat asymmetry in human sperm cells. | rheotaxis, the directed response to fluid velocity gradients, has been shown to facilitate stable upstream swimming of mammalian sperm cells along solid surfaces, suggesting a robust physical mechanism for long-distance navigation during fertilization. however, the dynamics by which a human sperm orients itself relative to an ambient flow is poorly understood. here, we combine microfluidic experiments with mathematical modeling and 3d flagellar beat reconstruction to quantify the response of ind ... | 2015 | 26655343 |
| high-throughput 3d tracking of bacteria on a standard phase contrast microscope. | bacteria employ diverse motility patterns in traversing complex three-dimensional (3d) natural habitats. 2d microscopy misses crucial features of 3d behaviour, but the applicability of existing 3d tracking techniques is constrained by their performance or ease of use. here we present a simple, broadly applicable, high-throughput 3d bacterial tracking method for use in standard phase contrast microscopy. bacteria are localized at micron-scale resolution over a range of 350 × 300 × 200 μm by maxim ... | 2015 | 26522289 |
| cold and hot extremozymes: industrial relevance and current trends. | the development of enzymes for industrial applications relies heavily on the use of microorganisms. the intrinsic properties of microbial enzymes, e.g., consistency, reproducibility, and high yields along with many others, have pushed their introduction into a wide range of products and industrial processes. extremophilic microorganisms represent an underutilized and innovative source of novel enzymes. these microorganisms have developed unique mechanisms and molecular means to cope with extreme ... | 2015 | 26539430 |
| enzymes from extreme environments and their industrial applications. | this article will discuss the importance of specific extremophilic enzymes for applications in industrial biotechnology. it will specifically address those enzymes that have applications in the area of biocatalysis. such enzymes now play an important role in catalyzing a variety of chemical conversions that were previously carried out by traditional chemistry. the biocatalytic process is carried out under mild conditions and with greater specificity. the enzyme process does not result in the tox ... | 2015 | 26528475 |
| temperature-sensitive salmonella enterica serovar enteritidis pt13a expressing essential proteins of psychrophilic bacteria. | synthetic genes based on deduced amino acid sequences of the nad-dependent dna ligase (liga) and ctp synthetase (pyrg) of psychrophilic bacteria were substituted for their native homologues in the genome of salmonella enterica serovar enteritidis phage type 13a (pt13a). the resulting strains were rendered temperature sensitive (ts) and did not revert to temperature resistance at a detectable level. at permissive temperatures, ts strains grew like the parental strain in broth medium and in macrop ... | 2015 | 26187965 |
| development of a cold-adapted pseudoalteromonas expression system for the pseudoalteromonas proteins intractable for the escherichia coli system. | although the escherichia coli expression system is the most commonly used expression system, some proteins are still difficult to be expressed by this system, such as proteins with high thermolability and enzymes that cannot mature by autoprocessing. therefore, it is necessary to develop alternative expression systems. in this study, a cold-adapted pseudoalteromonas expression system was developed. a shuttle vector was constructed, and a conjugational transfer system between e. coli and psychrop ... | 2015 | 26333173 |
| a non-poissonian flagellar motor switch increases bacterial chemotactic potential. | we investigate bacterial chemotactic strategies using run-tumble and run-reverse-flick motility patterns. the former is typically observed in enteric bacteria such as escherichia coli and salmonella and the latter was recently observed in the marine bacteria vibrio alginolyticus and is possibly exhibited by other polar flagellated species. it is shown that although the three-step motility pattern helps the bacterium to localize near hot spots, an exploitative behavior, its exploratory potential ... | 2015 | 26331263 |
| genetically modified proteins: functional improvement and chimeragenesis. | this review focuses on the emerging role of site-specific mutagenesis and chimeragenesis for the functional improvement of proteins in areas where traditional protein engineering methods have been extensively used and practically exhausted. the novel path for the creation of the novel proteins has been created on the farther development of the new structure and sequence optimization algorithms for generating and designing the accurate structure models in result of x-ray crystallography studies o ... | 2015 | 26211369 |
| psw2, a novel low-temperature-inducible gene expression vector based on a filamentous phage of the deep-sea bacterium shewanella piezotolerans wp3. | a low-temperature-inducible protein expression vector (psw2) based on a filamentous phage (sw1) of the deep-sea bacterium shewanella piezotolerans wp3 was constructed. this vector replicated stably in escherichia coli and shewanella species, and its copy number increased at low temperatures. the psw2 vector can be utilized as a complementation plasmid in wp3, and it can also be used for the production of complex cytochromes with multiple heme groups, which has the potential for application for m ... | 2015 | 26048946 |
| functional and spectroscopic characterization of chlamydomonas reinhardtii truncated hemoglobins. | the single-cell green alga chlamydomonas reinhardtii harbors twelve truncated hemoglobins (cr-trhbs). cr-trhb1-1 and cr-trhb1-8 have been postulated to be parts of the nitrogen assimilation pathway, and of a no-dependent signaling pathway, respectively. here, spectroscopic and reactivity properties of cr-trhb1-1, cr-trhb1-2, and cr-trhb1-4, all belonging to clsss 1 (previously known as group n or group i), are reported. the ferric form of cr-trhb1-1, cr-trhb1-2, and cr-trhb1-4 displays a stable ... | 2015 | 25993270 |
| marine extremophiles: a source of hydrolases for biotechnological applications. | the marine environment covers almost three quarters of the planet and is where evolution took its first steps. extremophile microorganisms are found in several extreme marine environments, such as hydrothermal vents, hot springs, salty lakes and deep-sea floors. the ability of these microorganisms to support extremes of temperature, salinity and pressure demonstrates their great potential for biotechnological processes. hydrolases including amylases, cellulases, peptidases and lipases from hyper ... | 2015 | 25854643 |
| a rhizosphere-associated symbiont, photobacterium spp. strain meld1, and its targeted synergistic activity for phytoprotection against mercury. | though heavy metal such as mercury is toxic to plants and microorganisms, the synergistic activity between them may offer benefit for surviving. in this study, a mercury-reducing bacterium, photobacterium spp. strain meld1, with an mic of 33 mg x kg(-1) mercury was isolated from a severely mercury and dioxin contaminated rhizosphere soil of reed (phragmites australis). while the whole genome sequencing of meld1 confirmed the presence of a mer operon, the mercury reductase mera gene showed 99% se ... | 2015 | 25816328 |
| redox regulation by reversible protein s-thiolation in bacteria. | low molecular weight (lmw) thiols function as thiol-redox buffers to maintain the reduced state of the cytoplasm. the best studied lmw thiol is the tripeptide glutathione (gsh) present in all eukaryotes and gram-negative bacteria. firmicutes bacteria, including bacillus and staphylococcus species utilize the redox buffer bacillithiol (bsh) while actinomycetes produce the related redox buffer mycothiol (msh). in eukaryotes, proteins are post-translationally modified to s-glutathionylated proteins ... | 2015 | 25852656 |
| evaluation of antioxidant producing potential of halophilic bacterial bionts from marine invertebrates. | marine invertebrates exposed to high levels of reactive oxygen species in the oceans have been reported to produce antioxidants as a major defense against free radical mediated toxicity; protecting their tissues from the damage associated with the oxidative stress. in view of this, the present study was carried out to determine the antioxidant activity of 100 bacterial bionts isolated from marine sponges, corals and a single bivalve. methanol extract of biont guvfcfm-3 produced 67.83% scavenging ... | 2015 | 26009651 |
| mechanism of thiosulfate oxidation in the soxa family of cysteine-ligated cytochromes. | thiosulfate dehydrogenase (tsda) catalyzes the oxidation of two thiosulfate molecules to form tetrathionate and is predicted to use an unusual cysteine-ligated heme as the catalytic cofactor. we have determined the structure of allochromatium vinosum tsda to a resolution of 1.3 å. this structure confirms the active site heme ligation, identifies a thiosulfate binding site within the active site cavity, and reveals an electron transfer route from the catalytic heme, through a second heme group to ... | 2015 | 25673696 |
| a globin domain in a neuronal transmembrane receptor of caenorhabditis elegans and ascaris suum: molecular modeling and functional properties. | we report the structural and biochemical characterization of glb-33, a putative neuropeptide receptor that is exclusively expressed in the nervous system of the nematode caenorhabditis elegans. this unique chimeric protein is composed of a 7-transmembrane domain (7tm), glb-33 7tm, typical of a g-protein-coupled receptor, and of a globin domain (gd), glb-33 gd. comprehensive sequence similarity searches in the genome of the parasitic nematode, ascaris suum, revealed a chimeric protein that is sim ... | 2015 | 25666609 |
| chloride activated halophilic α-amylase from marinobacter sp. emb8: production optimization and nanoimmobilization for efficient starch hydrolysis. | halophiles have been perceived as potential source of novel enzymes in recent years. the interest emanates from their ability to catalyze efficiently under high salt and organic solvents. present work encompasses production optimization and nanoimmobilization of an α-amylase from moderately halophilic marinobacter sp. emb8. media ingredients and culture conditions were optimized by "one-at-a-time approach." starch was found to be the best carbon source at 5% (w/v) concentration. glucose acted as ... | 2015 | 25667773 |
| life-style and genome structure of marine pseudoalteromonas siphovirus b8b isolated from the northwestern mediterranean sea. | marine viruses (phages) alter bacterial diversity and evolution with impacts on marine biogeochemical cycles, and yet few well-developed model systems limit opportunities for hypothesis testing. here we isolate phage b8b from the mediterranean sea using pseudoalteromonas sp. qc-44 as a host and characterize it using myriad techniques. morphologically, phage b8b was classified as a member of the siphoviridae family. one-step growth analyses showed that this siphovirus had a latent period of 70 mi ... | 2015 | 25587991 |
| modelling microbial metabolic rewiring during growth in a complex medium. | in their natural environment, bacteria face a wide range of environmental conditions that change over time and that impose continuous rearrangements at all the cellular levels (e.g. gene expression, metabolism). when facing a nutritionally rich environment, for example, microbes first use the preferred compound(s) and only later start metabolizing the other one(s). a systemic re-organization of the overall microbial metabolic network in response to a variation in the composition/concentration of ... | 2016 | 27881075 |
| genomic analysis of a marine bacterium: bioinformatics for comparison, evaluation, and interpretation of dna sequences. | a total of five highly related strains of an unidentified marine bacterium were analyzed through their short genome sequences (am260709-am260713). genome-to-genome distance (ggdc) showed high similarity to pseudoalteromonas haloplanktis (x67024). the generated unique quick response (qr) codes indicated no identity to other microbial species or gene sequences. chaos game representation (cgr) showed the number of bases concentrated in the area. guanine residues were highest in number followed by c ... | 2016 | 27882328 |
| identification of comamonas testosteroni as an androgen degrader in sewage. | numerous studies have reported the masculinization of freshwater wildlife exposed to androgens in polluted rivers. microbial degradation is a crucial mechanism for eliminating steroid hormones from contaminated ecosystems. the aerobic degradation of testosterone was observed in various bacterial isolates. however, the ecophysiological relevance of androgen-degrading microorganisms in the environment is unclear. here, we investigated the biochemical mechanisms and corresponding microorganisms of ... | 2016 | 27734937 |
| marine microbiological enzymes: studies with multiple strategies and prospects. | 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 ... | 2016 | 27669268 |
| antimicrobial compounds from eukaryotic microalgae against human pathogens and diseases in aquaculture. | the search for novel compounds of marine origin has increased in the last decades for their application in various areas such as pharmaceutical, human or animal nutrition, cosmetics or bioenergy. in this context of blue technology development, microalgae are of particular interest due to their immense biodiversity and their relatively simple growth needs. in this review, we discuss about the promising use of microalgae and microalgal compounds as sources of natural antibiotics against human path ... | 2016 | 27598176 |
| improving the secretory expression of an -galactosidase from aspergillus niger in pichia pastoris. | α-galactosidases are broadly used in feed, food, chemical, pulp, and pharmaceutical industries. however, there lacks a satisfactory microbial cell factory that is able to produce α-galactosidases efficiently and cost-effectively to date, which prevents these important enzymes from greater application. in this study, the secretory expression of an aspergillus niger α-galactosidase (aga) in pichia pastoris was systematically investigated. through codon optimization, signal peptide replacement, com ... | 2016 | 27548309 |
| using carbohydrate interaction assays to reveal novel binding sites in carbohydrate active enzymes. | carbohydrate active enzymes often contain auxiliary binding sites located either on independent domains termed carbohydrate binding modules (cbms) or as so-called surface binding sites (sbss) on the catalytic module at a certain distance from the active site. the sbss are usually critical for the activity of their cognate enzyme, though they are not readily detected in the sequence of a protein, but normally require a crystal structure of a complex for their identification. a variety of methods, ... | 2016 | 27504624 |
| genomic mechanisms for cold tolerance and production of exopolysaccharides in the arctic cyanobacterium phormidesmis priestleyi bc1401. | cyanobacteria are major primary producers in extreme cold ecosystems. many lineages of cyanobacteria thrive in these harsh environments, but it is not fully understood how they survive in these conditions and whether they have evolved specific mechanisms of cold adaptation. phormidesmis priestleyi is a cyanobacterium found throughout the cold biosphere (arctic, antarctic and alpine habitats). genome sequencing of p. priestleyi bc1401, an isolate from a cryoconite hole on the greenland ice sheet, ... | 2016 | 27485510 |
| bacterial and archaeal α-amylases: diversity and amelioration of the desirable characteristics for industrial applications. | industrial enzyme market has been projected to reach us$ 6.2 billion by 2020. major reasons for continuous rise in the global sales of microbial enzymes are because of increase in the demand for consumer goods and biofuels. among major industrial enzymes that find applications in baking, alcohol, detergent, and textile industries are α-amylases. these are produced by a variety of microbes, which randomly cleave α-1,4-glycosidic linkages in starch leading to the formation of limit dextrins. α-amy ... | 2016 | 27516755 |
| effect of tris, mops, and phosphate buffers on the hydrolysis of polyethylene terephthalate films by polyester hydrolases. | the enzymatic degradation of polyethylene terephthalate (pet) occurs at mild reaction conditions and may find applications in environmentally friendly plastic waste recycling processes. the hydrolytic activity of the homologous polyester hydrolases lc cutinase (lcc) from a compost metagenome and tfcut2 from thermobifida fusca kw3 against pet films was strongly influenced by the reaction medium buffers tris(hydroxymethyl)aminomethane (tris), 3-(n-morpholino)propanesulfonic acid (mops), and sodium ... | 2016 | 27642555 |
| effects of the linker region on the structure and function of modular gh5 cellulases. | the association of glycosyl hydrolases with catalytically inactive modules is a successful evolutionary strategy that is commonly used by biomass-degrading microorganisms to digest plant cell walls. the presence of accessory domains in these enzymes is associated with properties such as higher catalytic efficiency, extension of the catalytic interface and targeting of the enzyme to the proper substrate. however, the importance of the linker region in the synergistic action of the catalytic and a ... | 2016 | 27334041 |
| not all particles are equal: the selective enrichment of particle-associated bacteria from the mediterranean sea. | we have used two metagenomic approaches, direct sequencing of natural samples and sequencing after enrichment, to characterize communities of prokaryotes associated to particles. in the first approximation, different size filters (0.22 and 5 μm) were used to identify prokaryotic microbes of free-living and particle-attached bacterial communities in the mediterranean water column. a subtractive metagenomic approach was used to characterize the dominant microbial groups in the large size fraction ... | 2016 | 27446036 |
| pangenome evolution in the marine bacterium alteromonas. | we have examined a collection of the free-living marine bacterium alteromonas genomes with cores diverging in average nucleotide identities ranging from 99.98% to 73.35%, i.e., from microbes that can be considered members of a natural clone (like in a clinical epidemiological outbreak) to borderline genus level. the genomes were largely syntenic allowing a precise delimitation of the core and flexible regions in each. the core was 1.4 mb (ca. 30% of the typical strain genome size). recombination ... | 2016 | 27189983 |
| integrated (meta) genomic and synthetic biology approaches to develop new biocatalysts. | in recent years, the marine environment has been the subject of increasing attention from biotechnological and pharmaceutical industries as a valuable and promising source of novel bioactive compounds. marine biodiscovery programmes have begun to reveal the extent of novel compounds encoded within the enormous bacterial richness and diversity of the marine ecosystem. a combination of unique physicochemical properties and spatial niche-specific substrates, in wide-ranging and extreme habitats, un ... | 2016 | 27007381 |
| delineation of steroid-degrading microorganisms through comparative genomic analysis. | steroids are ubiquitous in natural environments and are a significant growth substrate for microorganisms. microbial steroid metabolism is also important for some pathogens and for biotechnical applications. this study delineated the distribution of aerobic steroid catabolism pathways among over 8,000 microorganisms whose genomes are available in the ncbi refseq database. combined analysis of bacterial, archaeal, and fungal genomes with both hidden markov models and reciprocal blast identified 2 ... | 2016 | 26956583 |
| temperature sensitivity conferred by liga alleles from psychrophilic bacteria upon substitution in mesophilic bacteria and a yeast species. | we have assembled a collection of 13 psychrophilic liga alleles that can serve as genetic elements for engineering mesophiles to a temperature-sensitive (ts) phenotype. when these liga alleles were substituted into francisella novicida, they conferred a ts phenotype with restrictive temperatures between 33 and 39°c. when the f. novicida liga hybrid strains were plated above their restrictive temperatures, eight of them generated temperature-resistant variants. for two alleles, the mutations that ... | 2016 | 26773080 |
| a diverse community of metal(loid) oxide respiring bacteria is associated with tube worms in the vicinity of the juan de fuca ridge black smoker field. | epibiotic bacteria associated with tube worms living in the vicinity of deep sea hydrothermal vents of the juan de fuca ridge in the pacific ocean were investigated for the ability to respire anaerobically on tellurite, tellurate, selenite, selenate, metavanadate and orthovanadate as terminal electron acceptors. out of 107 isolates tested, 106 were capable of respiration on one or more of these oxides, indicating that metal(loid) oxide based respiration is not only much more prevalent in nature ... | 2016 | 26914590 |
| a bacterial quorum-sensing precursor induces mortality in the marine coccolithophore, emiliania huxleyi. | interactions between phytoplankton and bacteria play a central role in mediating biogeochemical cycling and food web structure in the ocean. however, deciphering the chemical drivers of these interspecies interactions remains challenging. here, we report the isolation of 2-heptyl-4-quinolone (hhq), released by pseudoalteromonas piscicida, a marine gamma-proteobacteria previously reported to induce phytoplankton mortality through a hitherto unknown algicidal mechanism. hhq functions as both an an ... | 2016 | 26870019 |
| chemotaxis toward phytoplankton drives organic matter partitioning among marine bacteria. | the microenvironment surrounding individual phytoplankton cells is often rich in dissolved organic matter (dom), which can attract bacteria by chemotaxis. these "phycospheres" may be prominent sources of resource heterogeneity in the ocean, affecting the growth of bacterial populations and the fate of dom. however, these effects remain poorly quantified due to a lack of quantitative ecological frameworks. here, we used video microscopy to dissect with unprecedented resolution the chemotactic acc ... | 2016 | 26802122 |
| the pangenome of (antarctic) pseudoalteromonas bacteria: evolutionary and functional insights. | pseudoalteromonas is a genus of ubiquitous marine bacteria used as model organisms to study the biological mechanisms involved in the adaptation to cold conditions. a remarkable feature shared by these bacteria is their ability to produce secondary metabolites with a strong antimicrobial and antitumor activity. despite their biotechnological relevance, representatives of this genus are still lacking (with few exceptions) an extensive genomic characterization, including features involved in the e ... | 2017 | 28095778 |
| [fatty acid composition alteromonas-like bacteria isolated from the black sea water]. | alteromonas macleodii strains isolated from the black sea water were similar in their fatty acids composition with the type strain of this species. analysis of lipid composition of 10 a. macleodii strains isolated from the deep and surface water layers in different world ocean regions including the black sea water has shown that the deep and surface isolates of this species formed two groups different in their fatty acids profiles. the black sea isolates of pseudoalteromonas haloplanktis, p. cit ... | 2015 | 26638484 |
| cloning, expression, and characterization of a novel l-arabinose isomerase from the psychrotolerant bacterium pseudoalteromonas haloplanktis. | l-arabinose isomerase (l-ai, ec 5.3.1.4) catalyzes the isomerization between l-arabinose and l-ribulose, and most of the reported ones can also catalyze d-galactose to d-tagatose, except bacillus subtilis l-ai. in this article, the l-ai from the psychrotolerant bacterium pseudoalteromonas haloplanktis atcc 14393 was characterized. the enzyme showed no substrate specificity toward d-galactose, which was similar to b. subtilis l-ai but distinguished from other reported l-ais. the araa gene encodin ... | 2016 | 27586234 |
| modification of the secondary binding site of xylanases illustrates the impact of substrate selectivity on bread making. | to investigate the importance of substrate selectivity for xylanase functionality in bread making, the secondary binding site (sbs) of xylanases from bacillus subtilis (xbs) and pseudoalteromonas haloplanktis was modified. this resulted in two xylanases with increased relative activity toward water-unextractable wheat arabinoxylan (wu-ax) compared to water-extractable wheat arabinoxylan, i.e., an increased substrate selectivity, without changing other biochemical properties. addition of both mod ... | 2016 | 27282886 |
| stepwise optimization of a low-temperature bacillus subtilis expression system for "difficult to express" proteins. | in order to improve the overproduction of "difficult to express" proteins, a low-temperature expression system for bacillus subtilis based on the cold-inducible promoter of the desaturase-encoding des gene was constructed. selected regulatory dna sequence elements from b. subtilis genes known to be cold-inducible were fused to different model genes. it could be demonstrated that these regulatory elements are able to mediate increased heterologous gene expression, either by improved translation e ... | 2015 | 25851716 |
| pseudoalteromonas haloplanktis produces methylamine, a volatile compound active against burkholderia cepacia complex strains. | the antarctic marine bacterium pseudoalteromonas haloplanktis tac125 has been reported to produce several volatile organic compounds (vocs), which are able to inhibit the growth of burkholderia cepacia complex (bcc) strains, opportunistic pathogens responsible for the infection of immune-compromised patients. however, no specific antibacterial vocs have been identified to date. the purpose of the present study was to identify specific vocs that contribute to bcc inhibition by the antarctic strai ... | 2017 | 27989956 |
| strategies for the production of difficult-to-express full-length eukaryotic proteins using microbial cell factories: production of human alpha-galactosidase a. | obtaining high levels of pure proteins remains the main bottleneck of many scientific and biotechnological studies. among all the available recombinant expression systems, escherichia coli facilitates gene expression by its relative simplicity, inexpensive and fast cultivation, well-known genetics and the large number of tools available for its biotechnological application. however, recombinant expression in e. coli is not always a straightforward procedure and major obstacles are encountered wh ... | 2015 | 25616525 |
| functional adaptations of the bacterial chaperone trigger factor to extreme environmental temperatures. | trigger factor (tf) is the first molecular chaperone interacting cotranslationally with virtually all nascent polypeptides synthesized by the ribosome in bacteria. thermal adaptation of chaperone function was investigated in tfs from the antarctic psychrophile pseudoalteromonas haloplanktis, the mesophile escherichia coli and the hyperthermophile thermotoga maritima. this series covers nearly all temperatures encountered by bacteria. although structurally homologous, these tfs display strikingly ... | 2015 | 25389111 |
| recombinant production of a single-chain antibody fragment in pseudoalteromonas haloplanktis tac125. | recombinant protein production in cold-adapted bacteria has proved to be a valuable option to overcome solubility concerns often came up in conventional expression hosts. scfvs are examples of "difficult proteins" due to their tendency to form inclusion bodies when expressed in escherichia coli. in this paper, the recombinant production of a single-chain antibody (scfvox) in the psychrophilic bacterium pseudoalteromonas haloplanktis tac125 is reported. the expression vector for the scfvox produc ... | 2014 | 24535258 |
| identification and characterization of single-stranded dna-binding protein from the facultative psychrophilic bacteria pseudoalteromonas haloplanktis. | single-stranded dna-binding protein (ssb) plays an important role in dna metabolism such as dna replication, repair, and recombination, and is essential for cell survival. this study reports on the ssb-like gene cloning, gene expression and characterization of a single-stranded dna-binding protein of pseudoalteromonas haloplanktis (phassb) and is the first report of such a protein from psychrophilic microorganism. phassb possesses a high sequence similarity to escherichia coli ssb (48% identity ... | 2014 | 23953921 |
| energetics of protein stability at extreme environmental temperatures in bacterial trigger factors. | trigger factor is the first molecular chaperone interacting cotranslationally with virtually all nascent polypeptides synthesized by the ribosome in bacteria. the stability of this primary folding assistant was investigated using trigger factors from the antarctic psychrophile pseudoalteromonas haloplanktis, the mesophile escherichia coli, and the hyperthermophile thermotoga maritima. this series covers nearly all temperatures encountered by living organisms. we show that proteins adapt their st ... | 2013 | 23547956 |
| antarctic bacterial haemoglobin and its role in the protection against nitrogen reactive species. | in a cold and oxygen-rich environment such as antarctica, mechanisms for the defence against reactive oxygen and nitrogen species are needed and represent important components in the evolutionary adaptations. in the antarctic bacterium pseudoalteromonas haloplanktis tac125, the presence of multiple genes encoding 2/2 haemoglobins and a flavohaemoglobin strongly suggests that these proteins fulfil important physiological roles, perhaps associated to the peculiar features of the antarctic habitat. ... | 2013 | 23434851 |
| biodiversity and dynamics of the bacterial community of packaged king scallop (pecten maximus) meat during cold storage. | the microbial biodiversity and dynamics of king scallops meat and coral during cold storage (cold chain rupture: 1/3 storage time at 4 °c followed by 2/3 at 8 °c), was assessed by combining culture-dependant and -independent methods. products were packaged as follows: aerobic, vacuum packed and 3 different co2/n2 modified atmospheres and the impact of these conditions on the microbial communities was assessed. results indicated that under air (current packaging condition), the dominant species c ... | 2013 | 23664260 |
| stable, temperature-sensitive recombinant strain of mycobacterium smegmatis generated through the substitution of a psychrophilic liga gene. | a synthetic version of the liga gene encoding the nad-dependent dna ligase from the arctic bacterium pseudoalteromonas haloplanktis was substituted for its homolog in the chromosome of mycobacterium smegmatis. the resulting recombinant strain grew identically to the parent strain at permissive temperatures but failed to grow above 37°c. the temperature-sensitive phenotype was stable, and the strain failed to generate temperature-resistant forms at a detectable level. repeated passage of the hybr ... | 2015 | 26337150 |
| anti-biofilm activity of a long-chain fatty aldehyde from antarctic pseudoalteromonas haloplanktis tac125 against staphylococcus epidermidis biofilm. | staphylococcus epidermidis is a harmless human skin colonizer responsible for ~20% of orthopedic device-related infections due to its capability to form biofilm. nowadays there is an interest in the development of anti-biofilm molecules. marine bacteria represent a still underexploited source of biodiversity able to synthesize a broad range of bioactive compounds, including anti-biofilm molecules. previous results have demonstrated that the culture supernatant of antarctic marine bacterium pseud ... | 2017 | 28280714 |
| aquatic adaptation of a laterally acquired pectin degradation pathway in marine gammaproteobacteria. | mobile genomic islands distribute functional traits between microbes and habitats, yet it remains unclear how their proteins adapt to new environments. here we used a comparative phylogenomic and proteomic approach to show that the marine bacterium pseudoalteromonas haloplanktis ant/505 acquired a genomic island with a functional pathway for pectin catabolism. bioinformatics and biochemical experiments revealed that this pathway encodes a series of carbohydrate-active enzymes including two multi ... | 2017 | 28276126 |
| a novel synthetic medium and expression system for subzero growth and recombinant protein production in pseudoalteromonas haloplanktis tac125. | the antarctic bacterium pseudoalteromonas haloplanktis tac125 is a model organism of cold-adapted bacteria. the interest in the study of this psychrophilic bacterium stems from its capability either as a non-conventional system for production of recombinant protein and as a rich source of bioactive compounds. to further explore the biotechnological ability of p. haloplanktis tac125, we have developed a synthetic medium, containing d-gluconate and l-glutamate (gg), which allows the bacterium to g ... | 2017 | 27796433 |
| large-scale biofilm cultivation of antarctic bacterium pseudoalteromonas haloplanktis tac125 for physiologic studies and drug discovery. | microbial biofilms are mainly studied due to detrimental effects on human health but they are also well established in industrial biotechnology for the production of chemicals. moreover, biofilm can be considered as a source of novel drugs since the conditions prevailing within biofilm can allow the production of specific metabolites. antarctic bacterium pseudoalteromonas haloplanktis tac125 when grown in biofilm condition produces an anti-biofilm molecule able to inhibit the biofilm of the oppo ... | 2016 | 26847199 |
| sulfonamide inhibition studies of the γ-carbonic anhydrase from the antarctic bacterium pseudoalteromonas haloplanktis. | the antarctic bacterium pseudoalteromonas haloplanktis encodes for a γ-class carbonic anhydrase (ca, ec 4.2.1.1), which was cloned, purified and characterized. the enzyme (phacaγ) has a good catalytic activity for the physiologic reaction of co2 hydration to bicarbonate and protons, with a k(cat) of 1.4×10(5) s(-1) and a k(cat)/k(m) of 1.9×10(6) m(-1)×s(-1). a series of sulfonamides and a sulfamate were investigated as inhibitors of the new enzyme. methazolamide and indisulam showed the best inh ... | 2015 | 26174556 |
| cloning, characterization and anion inhibition studies of a new γ-carbonic anhydrase from the antarctic bacterium pseudoalteromonas haloplanktis. | a new γ-class carbonic anhydrase (ca, ec 4.2.1.1) was cloned, purified and characterized from the antarctic bacterium pseudoalteromonas haloplanktis, phacaγ. the enzyme has a medium-low catalytic activity for the physiologic reaction of co2 hydration to bicarbonate and protons, with a kcat of 1.4×10(5)s(-1) and a kcat/km of 1.9×10(6)m(-1)s(-1). an anion inhibition study of phacaγ with inorganic anions and small molecule inhibitors is also reported. many anions present in sea water, such as chlor ... | 2015 | 26145820 |
| structural flexibility of the heme cavity in the cold-adapted truncated hemoglobin from the antarctic marine bacterium pseudoalteromonas haloplanktis tac125. | truncated hemoglobins build one of the three branches of the globin protein superfamily. they display a characteristic two-on-two α-helical sandwich fold and are clustered into three groups (i, ii and iii) based on distinct structural features. truncated hemoglobins are present in eubacteria, cyanobacteria, protozoa and plants. here we present a structural, spectroscopic and molecular dynamics characterization of a group-ii truncated hemoglobin, encoded by the pshaa0030 gene from pseudoalteromon ... | 2015 | 26040838 |
| anti-biofilm activity of pseudoalteromonas haloplanktis tac125 against staphylococcus epidermidis biofilm: evidence of a signal molecule involvement? | staphylococcus epidermidis is recognized as cause of biofilm-associated infections and interest in the development of new approaches for s. epidermidis biofilm treatment has increased. in a previous paper we reported that the supernatant of antarctic bacterium pseudoalteromonas haloplanktis tac125 presents an anti-biofilm activity against s. epidermidis and preliminary physico-chemical characterization of the supernatant suggested that this activity is due to a polysaccharide. in this work we fu ... | 2015 | 25816412 |
| soluble recombinant protein production in pseudoalteromonas haloplanktis tac125. | solubility/activity issues are often experienced when immunoglobulin fragments are produced in conventional microbial cell factories. although several experimental approaches have been followed to solve, or at least minimize, the accumulation of the recombinant proteins into insoluble aggregates, sometimes the only alternative strategy is changing the protein production platform. in this chapter we describe the use of antarctic bacterium pseudoalteromonas haloplanktis tac125 as host of choice fo ... | 2015 | 25447868 |
| sterol and steroid catabolites from cholesterol produced by the psychrophile pseudoalteromonas haloplanktis. | pseudoalteromonas haloplanktis, a psychrotrophilic marine bacterium of biotechnological interest, shows anti-biofilm properties and is particularly relevant for cold storage of vacuum packed seafood. we focused our interest on the activation of cholesterol metabolism in this bacterium as the presence in its genome of a putative 3-ketosteroid-δ(1) -dehydrogenase. this study reports gc-ms and lc-ms/ms profiles of sterols/steroids and their derivatives found in cell extracts of p. haloplanktis grow ... | 2014 | 25230192 |
| genome-scale metabolic reconstruction and constraint-based modelling of the antarctic bacterium pseudoalteromonas haloplanktis tac125. | the antarctic strain pseudoalteromonas haloplanktis tac125 is one of the model organisms of cold-adapted bacteria and is currently exploited as a new alternative expression host for numerous biotechnological applications. here, we investigated several metabolic features of this strain through in silico modelling and functional integration of -omics data. a genome-scale metabolic model of p. haloplanktis tac125 was reconstructed, encompassing information on 721 genes, 1133 metabolites and 1322 re ... | 2015 | 24889559 |
| the cold-adapted γ-glutamyl-cysteine ligase from the psychrophile pseudoalteromonas haloplanktis. | a recombinant γ-glutamyl-cysteine ligase from the psychrophile pseudoalteromonas haloplanktis (rphgsha ii) was produced and characterised. this enzyme catalyses the first step of glutathione biosynthesis by forming γ-glutamyl-cysteine from glutamate and cysteine in an atp-dependent reaction. the other atp-dependent enzyme, glutathione synthetase (rphgshb), involved in the second step of the biosynthesis, was already characterised. rphgsha ii is a monomer of 58 kda and its activity was characteri ... | 2014 | 24864035 |
| structural and denaturation studies of two mutants of a cold adapted superoxide dismutase point to the importance of electrostatic interactions in protein stability. | a peculiar feature of the psychrophilic iron superoxide dismutase from pseudoalteromonas haloplanktis (phsod) is the presence in its amino acid sequence of a reactive cysteine (cys57). to define the role of this residue, a structural characterization of the effect of two phsod mutations, c57s and c57r, was performed. thermal and denaturant-induced unfolding of wild type and mutant phsod followed by circular dichroism and fluorescence studies revealed that c→r substitution alters the thermal stab ... | 2014 | 24440460 |
| the globins of cold-adapted pseudoalteromonas haloplanktis tac125: from the structure to the physiological functions. | evolution allowed antarctic microorganisms to grow successfully under extreme conditions (low temperature and high o2 content), through a variety of structural and physiological adjustments in their genomes and development of programmed responses to strong oxidative and nitrosative stress. the availability of genomic sequences from an increasing number of cold-adapted species is providing insights to understand the molecular mechanisms underlying crucial physiological processes in polar organism ... | 2013 | 24054800 |
| statistical approach for the enhanced production of cold-active β-galactosidase from thalassospira frigidphilosprofundus: a novel marine psychrophile from deep waters of bay of bengal. | in the present investigation thalassospira frigidphilosprofundus, a novel species from the deep waters of the bay of bengal, was explored for the production of cold-active β-galactosidase by submerged fermentation using marine broth medium as the basal medium. effects of various medium constituents, namely, carbon, nitrogen source, ph, and temperature, were investigated using a conventional one-factor-at-a-time method. it was found that lactose, yeast extract, and bactopeptones are the most infl ... | 2013 | 23876137 |
| ligand-rebinding kinetics of 2/2 hemoglobin from the antarctic bacterium pseudoalteromonas haloplanktis tac125. | kinetic studies were performed on ligand rebinding to a cold-adapted globin of the antarctic bacterium pseudoalteromonas haloplanktis tac125 (ph-2/2hbo). this 2/2 hemoglobin displays a rapid spectroscopic phase that is independent of co concentration, followed by the standard bimolecular recombination. while the geminate recombination usually occurs on a ns timescale, ph-2/2hbo displays a component of about 1μs that accounts for half of the geminate phase at 8°c, indicative of a relatively slow ... | 2013 | 23429181 |
| anti-biofilm activity of the antarctic marine bacterium pseudoalteromonas haloplanktis tac125. | considering the increasing impact of bacterial biofilms on human health, industrial and food-processing activities, the interest in the development of new approaches for the prevention and treatment of adhesion and biofilm formation capabilities has increased. a viable approach should target adhesive properties without affecting bacterial vitality in order to avoid the rapid appearance of escape mutants. it is known that marine bacteria belonging to the genus pseudoalteromonas produce compounds ... | 2013 | 23411371 |
| characterization of a cold-adapted glutathione synthetase from the psychrophile pseudoalteromonas haloplanktis. | glutathione (gsh) biosynthesis occurs through two atp-dependent reactions, usually involving distinct enzymes; in the second step of this process, catalysed by glutathione synthetase (gshb), gsh is formed from γ-glutamylcysteine and glycine. a recombinant form of gshb from the cold-adapted source pseudoalteromonas haloplanktis (rphgshb) was purified and characterised. the enzyme formed a disulfide adduct with β-mercaptoethanol, when purified in the presence of this reducing agent. the homotetram ... | 2012 | 22777241 |
| is there a cold shock response in the antarctic psychrophile pseudoalteromonas haloplanktis? | the growth behavior and the proteomic response after a cold shock were investigated in the psychrophilic antarctic bacterium pseudoalteromonas haloplanktis. remarkably, no cold-induced proteins were observed in the proteome, whereas some key proteins were repressed. this suggests noticeable differences in the cold shock response between a true psychrophile and mesophiles. | 2012 | 22552624 |
| properties of the endogenous components of the thioredoxin system in the psychrophilic eubacterium pseudoalteromonas haloplanktis tac 125. | the endogenous components of the thioredoxin system in the antarctic eubacterium pseudoalteromonas haloplanktis have been purified and characterised. the temperature dependence of the activities sustained by thioredoxin (phtrx) and thioredoxin reductase (phtrxr) pointed to their adaptation in the cold growth environment. phtrxr was purified as a flavoenzyme and its activity was significantly enhanced in the presence of molar concentration of monovalent cations. the energetics of the partial reac ... | 2012 | 22527046 |
| qm/mm reweighting free energy scf for geometry optimization on extensive free energy surface of enzymatic reaction. | we developed a quantum mechanical/molecular mechanical (qm/mm) free energy geometry optimization method by which the geometry of a quantum chemically treated (qm) molecule is optimized on a free energy surface defined with thermal distribution of the surrounding molecular environment obtained by molecular dynamics simulation with a molecular mechanics (mm) force field. the method called qm/mm reweighting free energy self-consistent field combines a mean field theory of qm/mm free energy geometry ... | 2012 | 26592893 |