Publications
Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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a microbial sensor for organophosphate hydrolysis exploiting an engineered specificity switch in a transcription factor. | a whole-cell biosensor utilizing a transcription factor (tf) is an effective tool for sensitive and selective detection of specialty chemicals or anthropogenic molecules, but requires access to an expanded repertoire of tfs. using homology modeling and ligand docking for binding pocket identification, assisted by conservative mutations in the pocket, we engineered a novel specificity in an acinetobacter tf, pobr, to 'sense' a chemical p-nitrophenol (pnp) and measured the response via a fluoresce ... | 2016 | 27536006 |
bacterial dispersal promotes biodegradation in heterogeneous systems exposed to osmotic stress. | contaminant biodegradation in soils is hampered by the heterogeneous distribution of degrading communities colonizing isolated microenvironments as a result of the soil architecture. over the last years, soil salinization was recognized as an additional problem especially in arid and semiarid ecosystems as it drastically reduces the activity and motility of bacteria. here, we studied the importance of different spatial processes for benzoate biodegradation at an environmentally relevant range of ... | 2016 | 27536297 |
from the lab to the farm: an industrial perspective of plant beneficial microorganisms. | any successful strategy aimed at enhancing crop productivity with microbial products ultimately relies on the ability to scale at regional to global levels. microorganisms that show promise in the lab may lack key characteristics for widespread adoption in sustainable and productive agricultural systems. this paper provides an overview of critical considerations involved with taking a strain from discovery to the farmer's field. in addition, we review some of the most effective microbial product ... | 2016 | 27540383 |
degradation capacities of bacteria and yeasts isolated from the gut of dendroctonus rhizophagus (curculionidae: scolytinae). | bark beetles (curculionidae: scolytinae) feed on the xylem and phloem of their host, which are composed of structural carbohydrates and organic compounds that are not easily degraded by the insects. some of these compounds might be hydrolyzed by digestive enzymes produced by microbes present in the gut of these insects. in this study, we evaluated the enzymatic capacity of bacteria (acinetobacter lwoffii, arthrobacter sp., pseudomonas putida, pseudomonas azotoformans, and rahnella sp.) and yeast ... | 2017 | 27544667 |
transcriptome analysis of pseudomonas aeruginosa pao1 grown at both body and elevated temperatures. | functional genomics research can give us valuable insights into bacterial gene function. rna sequencing (rna-seq) can generate information on transcript abundance in bacteria following abiotic stress treatments. in this study, we used the rna-seq technique to study the transcriptomes of the opportunistic nosocomial pathogen pseudomonas aeruginosa pao1 following heat shock. samples were grown at both the human body temperature (37 °c) and an arbitrarily-selected temperature of 46 °c. in this work ... | 2016 | 27547539 |
functional genomic analyses of enterobacter, anopheles and plasmodium reciprocal interactions that impact vector competence. | malaria exerts a tremendous socioeconomic impact worldwide despite current control efforts, and novel disease transmission-blocking strategies are urgently needed. the enterobacter bacterium esp_z, which is naturally harboured in the mosquito midgut, can inhibit the development of plasmodium parasites prior to their invasion of the midgut epithelium through a mechanism that involves oxidative stress. here, a multifaceted approach is used to study the tripartite interactions between the mosquito, ... | 2016 | 27549662 |
recent advances on multi-parameter flow cytometry to characterize antimicrobial treatments. | the investigation on antimicrobial mechanisms is a challenging and crucial issue in the fields of food or clinical microbiology, as it constitutes a prerequisite to the development of new antimicrobial processes or compounds, as well as to anticipate phenomenon of microbial resistance. nowadays it is accepted that a cells population exposed to a stress can cause the appearance of different cell populations and in particular sub-lethally compromised cells which could be defined as viable but non- ... | 2016 | 27551279 |
high quality draft genome sequence of the type strain of pseudomonas lutea ok2(t), a phosphate-solubilizing rhizospheric bacterium. | pseudomonas lutea ok2(t) (=lmg 21974(t), cect 5822(t)) is the type strain of the species and was isolated from the rhizosphere of grass growing in spain in 2003 based on its phosphate-solubilizing capacity. in order to identify the functional significance of phosphate solubilization in pseudomonas plant growth promoting rhizobacteria, we describe here the phenotypic characteristics of strain ok2(t) along with its high-quality draft genome sequence, its annotation, and analysis. the genome is com ... | 2016 | 27555890 |
toxin yafq reduces escherichia coli growth at low temperatures. | toxin/antitoxin (ta) systems reduce metabolism under stress; for example, toxin yafq of the yafq/dinj escherichia coli ta system reduces growth by cleaving transcripts with in-frame 5'-aaa-g/a-3' sites, and antitoxin dinj is a global regulator that represses its locus as well as controls levels of the stationary sigma factor rpos. here we investigated the influence on cell growth at various temperatures and found that deletion of the antitoxin gene, dinj, resulted in both reduced metabolism and ... | 2016 | 27557125 |
spatial pattern of copper phosphate precipitation involves in copper accumulation and resistance of unsaturated pseudomonas putida cz1 biofilm. | bacterial biofilms are spatially structured communities that contain bacterial cells with a wide range of physiological states. the spatial distribution and speciation of copper in unsaturated pseudomonas putida cz1 biofilms that accumulated 147.0 mg copper per g dry weight were determined by transmission electron microscopy coupled with energy dispersive x-ray analysis, and micro-x-ray fluorescence microscopy coupled with micro-x-ray absorption near edge structure (micro-xanes) analysis. it was ... | 2016 | 27558435 |
comparative genomics of an endophytic pseudomonas putida isolated from mango orchard. | we analyzed the genome sequence of an endophytic bacterial strain pseudomonas putida tji51 isolated from mango bark tissues. next generation dna sequencing and short read de novo assembly generated the 5,805,096 bp draft genome of p. putida tji51. out of 6,036 protein coding genes in p. putida tji51 sequences, 4,367 (72%) were annotated with functional specifications, while the remaining encoded hypothetical proteins. comparative genome sequence analysis revealed that the p. putida tji51genome c ... | 2016 | 27560648 |
novel nad+-farnesal dehydrogenase from polygonum minus leaves. purification and characterization of enzyme in juvenile hormone iii biosynthetic pathway in plant. | juvenile hormone iii is of great concern due to negative effects on major developmental and reproductive maturation in insect pests. thus, the elucidation of enzymes involved jh iii biosynthetic pathway has become increasing important in recent years. one of the enzymes in the jh iii biosynthetic pathway that remains to be isolated and characterized is farnesal dehydrogenase, an enzyme responsible to catalyze the oxidation of farnesal into farnesoic acid. a novel nad+-farnesal dehydrogenase of p ... | 2016 | 27560927 |
immune modulation enables a specialist insect to benefit from antibacterial withanolides in its host plant. | the development of novel plant chemical defenses and counter adaptations by herbivorous insect could continually drive speciation, producing more insect specialists than generalists. one approach to test this hypothesis is to compare closely related generalist and specialist species to reveal the associated costs and benefits of these different adaptive strategies. we use the specialized moth heliothis subflexa, which feeds exclusively on plants in the genus physalis, and its close generalist re ... | 2016 | 27561781 |
nitrogen regulation of the xyl genes of pseudomonas putida mt-2 propagates into a significant effect of nitrate on m-xylene mineralization in soil. | the nitrogen species available in the growth medium are key factors determining expression of xyl genes for biodegradation of aromatic compounds by pseudomonas putida. nitrogen compounds are frequently amended to promote degradation at polluted sites, but it remains unknown how regulation observed in the test tube is propagated into actual catabolism of, e.g. m-xylene in soil, the natural habitat of this bacterium. to address this issue, we have developed a test-tube-to-soil model system that ex ... | 2016 | 27561962 |
replisome assembly at bacterial chromosomes and iteron plasmids. | the proper initiation and occurrence of dna synthesis depends on the formation and rearrangements of nucleoprotein complexes within the origin of dna replication. in this review article, we present the current knowledge on the molecular mechanism of replication complex assembly at the origin of bacterial chromosome and plasmid replicon containing direct repeats (iterons) within the origin sequence. we describe recent findings on chromosomal and plasmid replication initiators, dnaa and rep protei ... | 2016 | 27563644 |
efficient reconstruction of predictive consensus metabolic network models. | understanding cellular function requires accurate, comprehensive representations of metabolism. genome-scale, constraint-based metabolic models (gsms) provide such representations, but their usability is often hampered by inconsistencies at various levels, in particular for concurrent models. commgen, our tool for consensus metabolic model generation, automatically identifies inconsistencies between concurrent models and semi-automatically resolves them, thereby contributing to consolidate knowl ... | 2016 | 27563720 |
competitive adsorption of pb and cd on bacteria-montmorillonite composite. | the characteristics and mechanisms of competitive adsorption of trace metals on bacteria-associated clay mineral composites have never been studied, despite their being among the most common organic-mineral complexes in geological systems. herein, competitive adsorption of pb and cd on pseudomonas putida-montmorillonite composite was investigated through adsorption-desorption experiment, isothermal titration calorimetry (itc), and synchrotron micro x-ray fluorescence (μ-xrf). from the experiment ... | 2016 | 27566847 |
molecular and structural considerations of tf-dna binding for the generation of biologically meaningful and accurate phylogenetic footprinting analysis: the lysr-type transcriptional regulator family as a study model. | the goal of most programs developed to find transcription factor binding sites (tfbss) is the identification of discrete sequence motifs that are significantly over-represented in a given set of sequences where a transcription factor (tf) is expected to bind. these programs assume that the nucleotide conservation of a specific motif is indicative of a selective pressure required for the recognition of a tf for its corresponding tfbs. despite their extensive use, the accuracies reached with these ... | 2016 | 27567672 |
prevalence and antimicrobial resistance pattern of bacterial strains isolated from patients with urinary tract infection in messalata central hospital, libya. | to investigate the prevalence of urinary tract infection among patients at messalata central hospital, libya, to identify the causative bacteria, and to explore their resistance pattern to antimicrobials. | 2016 | 27569886 |
bioaugmentation: an emerging strategy of industrial wastewater treatment for reuse and discharge. | a promising long-term and sustainable solution to the growing scarcity of water worldwide is to recycle and reuse wastewater. in wastewater treatment plants, the biodegradation of contaminants or pollutants by harnessing microorganisms present in activated sludge is one of the most important strategies to remove organic contaminants from wastewater. however, this approach has limitations because many pollutants are not efficiently eliminated. to counterbalance the limitations, bioaugmentation ha ... | 2016 | 27571089 |
burns infection profile of singapore: prevalence of multidrug-resistant acinetobacter baumannii and the role of blood cultures. | with various changes implemented such as perioperative antibiotics for tangential excision, this retrospective study reviews the infection profile of burn patients at singapore's only centralized burns unit. worldwide, the appearance of multidrug-resistant (mdr) strains of acinetobacter baumannii (a. baumannii) continues to worsen patient outcomes. this study also surveys the role of blood cultures in burns at our unit. | 2016 | 27574683 |
expression, purification and characterization of an endoglucanase from serratia proteamaculans cdbb-1961, isolated from the gut of dendroctonus adjunctus (coleoptera: scolytinae). | serratia proteamaculans cdbb-1961, a gut symbiont from the roundheaded pine beetle dendroctonus adjunctus, displayed strong cellulolytic activity on agar-plates with carboxymethyl cellulose (cmc) as carbon source. automatic genome annotation of s. proteamaculans made possible the identification of a single endoglucanase encoding gene, designated spr cel8a. the predicted protein, named spr cel8a shows high similarity (59-94 %) to endo-1,4-β-d-glucanases (ec 3.2.1.4) from the glycoside hydrolase f ... | 2016 | 27576896 |
structural and kinetic properties of the aldehyde dehydrogenase nahf, a broad substrate specificity enzyme for aldehyde oxidation. | the salicylaldehyde dehydrogenase (nahf) catalyzes the oxidation of salicylaldehyde to salicylate using nad(+) as a cofactor, the last reaction of the upper degradation pathway of naphthalene in pseudomonas putida g7. the naphthalene is an abundant and toxic compound in oil and has been used as a model for bioremediation studies. the steady-state kinetic parameters for oxidation of aliphatic or aromatic aldehydes catalyzed by 6xhis-nahf are presented. the 6xhis-nahf catalyzes the oxidation of ar ... | 2016 | 27580341 |
comparison of the complete genome sequences of four γ-hexachlorocyclohexane-degrading bacterial strains: insights into the evolution of bacteria able to degrade a recalcitrant man-made pesticide. | γ-hexachlorocyclohexane (γ-hch) is a recalcitrant man-made chlorinated pesticide. here, the complete genome sequences of four γ-hch-degrading sphingomonad strains, which are most unlikely to have been derived from one ancestral γ-hch degrader, were compared. together with several experimental data, we showed that (i) all the four strains carry almost identical lina to line genes for the conversion of γ-hch to maleylacetate (designated "specific" lin genes), (ii) considerably different genes are ... | 2016 | 27581378 |
the structure of the periplasmic sensor domain of the histidine kinase cuss shows unusual metal ion coordination at the dimeric interface. | in bacteria, two-component systems act as signaling systems to respond to environmental stimuli. two-component systems generally consist of a sensor histidine kinase and a response regulator, which work together through histidyl-aspartyl phosphorelay to result in gene regulation. one of the two-component systems in escherichia coli, cuss-cusr, is known to induce expression of cuscfba genes at increased periplasmic cu(i) and ag(i) concentrations to help maintain metal ion homeostasis. cuss is a m ... | 2016 | 27583660 |
clinical relevance of molecular identification of microorganisms and detection of antimicrobial resistance genes in bloodstream infections of paediatric cancer patients. | bloodstream infections (bsis) are the major cause of mortality in cancer patients. molecular techniques are used for rapid diagnosis of bsi, allowing early therapy and improving survival. we aimed to establish whether real-time quantitative polymerase chain reaction (qpcr) could improve early diagnosis and therapy in paediatric cancer patients, and describe the predominant pathogens of bsi and their antimicrobial susceptibility. | 2016 | 27585633 |
cyp101j2, cyp101j3, and cyp101j4, 1,8-cineole-hydroxylating cytochrome p450 monooxygenases from sphingobium yanoikuyae strain b2. | we report the isolation and characterization of three new cytochrome p450 monooxygenases: cyp101j2, cyp101j3, and cyp101j4. these p450s were derived from sphingobium yanoikuyae b2, a strain that was isolated from activated sludge based on its ability to fully mineralize 1,8-cineole. genome sequencing of this strain in combination with purification of native 1,8-cineole-binding proteins enabled identification of 1,8-cineole-binding p450s. the p450 enzymes were cloned, heterologously expressed (n- ... | 2016 | 27590809 |
a rapid method to estimate nadh regeneration rates in living cells. | we introduce a rapid whole cell assay for the estimation of nadh regeneration rates based on the fluorescent dye resazurin. a co-feed of formate and glucose, known to increase the intrinsic nadh regeneration rate of p. putida kt2440, was chosen as model system for the validation of this assay. | 2016 | 27592588 |
high quality draft genome sequences of pseudomonas fulva dsm 17717(t), pseudomonas parafulva dsm 17004(t) and pseudomonas cremoricolorata dsm 17059(t) type strains. | pseudomonas has the highest number of species out of any genus of gram-negative bacteria and is phylogenetically divided into several groups. the pseudomonas putida phylogenetic branch includes at least 13 species of environmental and industrial interest, plant-associated bacteria, insect pathogens, and even some members that have been found in clinical specimens. in the context of the genomic encyclopedia of bacteria and archaea project, we present the permanent, high-quality draft genomes of t ... | 2016 | 27594974 |
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 |
screen of non-annotated small secreted proteins of pseudomonas syringae reveals a virulence factor that inhibits tomato immune proteases. | pseudomonas syringae pv. tomato dc3000 (ptodc3000) is an extracellular model plant pathogen, yet its potential to produce secreted effectors that manipulate the apoplast has been under investigated. here we identified 131 candidate small, secreted, non-annotated proteins from the ptodc3000 genome, most of which are common to pseudomonas species and potentially expressed during apoplastic colonization. we produced 43 of these proteins through a custom-made gateway-compatible expression system for ... | 2016 | 27603016 |
involvement of type vi secretion system in secretion of iron chelator pyoverdine in pseudomonas taiwanensis. | rice bacterial blight caused by xanthomonas oryzae pv. oryzae (xoo) is one of the most destructive rice diseases worldwide. therefore, in addition to breeding disease-resistant rice cultivars, it is desirable to develop effective biocontrol agents against xoo. here, we report that a soil bacterium pseudomonas taiwanensis displayed strong antagonistic activity against xoo. using matrix-assisted laser desorption/ionization imaging mass spectrometry, we identified an iron chelator, pyoverdine, secr ... | 2016 | 27605490 |
fluorescent pseudomonas strains with only few plant-beneficial properties are favored in the maize rhizosphere. | plant growth-promoting rhizobacteria (pgpr) enhance plant health and growth using a variety of traits. effective pgpr strains typically exhibit multiple plant-beneficial properties, but whether they are better adapted to the rhizosphere than pgpr strains with fewer plant-beneficial properties is unknown. here, we tested the hypothesis that strains with higher numbers of plant-beneficial properties would be preferentially selected by plant roots. to this end, the co-occurrence of 18 properties in ... | 2016 | 27610110 |
the diversity of mtdna rns introns among strains of ophiostoma piliferum, ophiostoma pluriannulatum and related species. | based on previous studies, it was suspected that the mitochondrial rns gene within the ophiostomatales is rich in introns. this study focused on a collection of strains representing ophiostoma piliferum, ophiostoma pluriannulatum and related species that cause blue-stain; these fungi colonize the sapwood of trees and impart a dark stain. this reduces the value of the lumber. the goal was to examine the mtdna rns intron landscape for these important blue stain fungi in order to facilitate future ... | 2016 | 27610327 |
use of maldi-tof ms and culturomics to identify mosquitoes and their midgut microbiota. | mosquitoes transmit a wide range of human parasitic and viral diseases. in recent years, new techniques such as maldi-tof ms have been developed to identify mosquitoes at the species level, which is key for entomological surveys. additionally, there is increasing interest in the mosquito microbiota and its role in vector capacity. | 2016 | 27613238 |
physiological response of escherichia coli o157:h7 sakai to dynamic changes in temperature and water activity as experienced during carcass chilling. | enterohemeorrhagic escherichia coli is a leading cause of foodborne illness, with the majority of cases linked to foods of bovine origin. currently, no completely effective method for controlling this pathogen during carcass processing exists. understanding how this pathogen behaves under those stress conditions experienced on the carcass during chilling in cold air could offer opportunities for development or improvement of effective decontamination processes. therefore, we studied the growth k ... | 2016 | 27615263 |
systems metabolic engineering of corynebacterium glutamicum for the production of the carbon-5 platform chemicals 5-aminovalerate and glutarate. | the steadily growing world population and our ever luxurious life style, along with the simultaneously decreasing fossil resources has confronted modern society with the issue and need of finding renewable routes to accommodate for our demands. shifting the production pipeline from raw oil to biomass requires efficient processes for numerous platform chemicals being produced with high yield, high titer and high productivity. | 2016 | 27618862 |
primary succession of nitrogen cycling microbial communities along the deglaciated forelands of tianshan mountain, china. | structural succession and its driving factors for nitrogen (n) cycling microbial communities during the early stages of soil development (0-44 years) were studied along a chronosequence in the glacial forelands of the tianshan mountain no.1 glacier in the arid and semi-arid region of central asia. we assessed the abundance and population of functional genes affiliated with n-fixation (nifh), nitrification (bacterial and archaeal amoa), and denitrification (nirk/s and nosz) in a glacier foreland ... | 2016 | 27625641 |
matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (maldi-tof ms) based microbial identifications: challenges and scopes for microbial ecologists. | matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (maldi-tof ms) based biotyping is an emerging technique for high-throughput and rapid microbial identification. due to its relatively higher accuracy, comprehensive database of clinically important microorganisms and low-cost compared to other microbial identification methods, maldi-tof ms has started replacing existing practices prevalent in clinical diagnosis. however, applicability of maldi-tof ms in the area of micr ... | 2016 | 27625644 |
a pseudo-outbreak of pseudomonas putida and stenotrophomonas maltophilia in a bronchoscopy unit. | endoscopes represent the medical devices most commonly linked to health care-associated outbreaks and pseudo-outbreaks. most of the recent outbreaks and pseudo-outbreaks have resulted from contaminated automated endoscope reprocessors (aer) or the use of damaged or malfunctioning bronchoscopes or contaminated equipment. | 2016 | 27627819 |
fine-tuning of amino sugar homeostasis by eiia(ntr) in salmonella typhimurium. | the nitrogen-metabolic phosphotransferase system, pts(ntr), consists of the enzymes i(ntr), npr and iia(ntr) that are encoded by ptsp, ptso, and ptsn, respectively. due to the proximity of ptso and ptsn to rpon, the pts(ntr) system has been postulated to be closely related with nitrogen metabolism. to define the correlation between pts(ntr) and nitrogen metabolism, we performed ligand fishing with eiia(ntr) as a bait and revealed that d-glucosamine-6-phosphate synthase (glms) directly interacted ... | 2016 | 27628932 |
interspecific bacterial interactions are reflected in multispecies biofilm spatial organization. | interspecies interactions are essential for the persistence and development of any kind of complex community, and microbial biofilms are no exception. multispecies biofilms are structured and spatially defined communities that have received much attention due to their omnipresence in natural environments. species residing in these complex bacterial communities usually interact both intra- and interspecifically. such interactions are considered to not only be fundamental in shaping overall biomas ... | 2016 | 27630624 |
current state of knowledge in microbial degradation of polycyclic aromatic hydrocarbons (pahs): a review. | polycyclic aromatic hydrocarbons (pahs) include a group of organic priority pollutants of critical environmental and public health concern due to their toxic, genotoxic, mutagenic and/or carcinogenic properties and their ubiquitous occurrence as well as recalcitrance. the increased awareness of their various adverse effects on ecosystem and human health has led to a dramatic increase in research aimed toward removing pahs from the environment. pahs may undergo adsorption, volatilization, photoly ... | 2016 | 27630626 |
the expression of many chemoreceptor genes depends on the cognate chemoeffector as well as on the growth medium and phase. | chemoreceptor-based signaling is a major bacterial signal transduction mechanism. escherichia coli, the traditional model, has five chemoreceptors. recent genome analyses have shown that many bacteria have a much higher number of chemoreceptors. pseudomonas putida kt2440 is an alternative model that has 27 chemoreceptors and the cognate chemoeffector is known for many of them. here, we address the question whether and which factors modulate chemoreceptor gene expression. we report reverse transc ... | 2016 | 27632030 |
a highly efficient sorbitol dehydrogenase from gluconobacter oxydans g624 and improvement of its stability through immobilization. | a sorbitol dehydrogenase (gosldh) from gluconobacter oxydans g624 (g. oxydans g624) was expressed in escherichia coli bl21(de3)-codonplus ril. the complete 1455-bp codon-optimized gene was amplified, expressed, and thoroughly characterized for the first time. gosldh exhibited km and kcat values of 38.9 mm and 3820 s(-1) toward l-sorbitol, respectively. the enzyme exhibited high preference for nadp(+) (vs. only 2.5% relative activity with nad(+)). gosldh sequencing, structure analyses, and bioche ... | 2016 | 27633501 |
genomic, transcriptomic and proteomic analysis provide insights into the cold adaptation mechanism of the obligate psychrophilic fungus mrakia psychrophila. | mrakia psychrophila is an obligate psychrophilic fungus. the cold adaptation mechanism of psychrophilic fungi remains unknown. comparative genomics analysis indicated that m. psychrophila had a specific codon usage preference, especially for codons of gly and arg and its major facilitator superfamily (mfs) transporter gene family was expanded. transcriptomic analysis revealed that genes involved in ribosome and energy metabolism were upregulated at 4°c, while genes involved in unfolded protein b ... | 2016 | 27633791 |
saccharomyces cerevisiae metabolism in ecological context. | the architecture and regulation of saccharomyces cerevisiae metabolic network are among the best studied owing to its widespread use in both basic research and industry. yet, several recent studies have revealed notable limitations in explaining genotype-metabolic phenotype relations in this yeast, especially when concerning multiple genetic/environmental perturbations. apparently unexpected genotype-phenotype relations may originate in the evolutionarily shaped cellular operating principles bei ... | 2016 | 27634775 |
recent advances in synthetic biosafety. | synthetically engineered organisms hold promise for a broad range of medical, environmental, and industrial applications. organisms can potentially be designed, for example, for the inexpensive and environmentally benign synthesis of pharmaceuticals and industrial chemicals, for the cleanup of environmental pollutants, and potentially even for biomedical applications such as the targeting of specific diseases or tissues. however, the use of synthetically engineered organisms comes with several r ... | 2016 | 27635235 |
complex interplay between fleq, cyclic diguanylate and multiple σ factors coordinately regulates flagellar motility and biofilm development in pseudomonas putida. | most bacteria alternate between a free living planktonic lifestyle and the formation of structured surface-associated communities named biofilms. the transition between these two lifestyles requires a precise and timely regulation of the factors involved in each of the stages that has been likened to a developmental process. here we characterize the involvement of the transcriptional regulator fleq and the second messenger cyclic diguanylate in the coordinate regulation of multiple functions rel ... | 2016 | 27636892 |
cloning, expression, and characterization of a peptidoglycan hydrolase from the burkholderia pseudomallei phage st79. | the lytic phage st79 of burkholderia pseudomallei can lyse a broad range of its host including antibiotic resistant isolates from within using a set of proteins, holin, lysb, lysc and endolysin, a peptidoglycan (pg) hydrolase enzyme. the phage st79 endolysin gene identified as peptidase m15a was cloned, expressed and purified to evaluate its potential to lyse pathogenic bacteria. the molecular size of the purified enzyme is approximately 18 kda and the in silico study cited here indicated the pr ... | 2016 | 27637947 |
structure and catalytic mechanism of monodehydroascorbate reductase, mdhar, from oryza sativa l. japonica. | ascorbic acid (asa) maintains redox homeostasis by scavenging reactive oxygen species from prokaryotes to eukaryotes, especially plants. the enzyme monodehydroascorbate reductase (mdhar) regenerates asa by catalysing the reduction of monodehydroascorbate, using nadh or nadph as an electron donor. the detailed recycling mechanism of mdhar remains unclear due to lack of structural information. here, we present the crystal structures of mdhar in the presence of cofactors, nicotinamide adenine dinuc ... | 2016 | 27652777 |
identification of gefitinib off-targets using a structure-based systems biology approach; their validation with reverse docking and retrospective data mining. | gefitinib, an egfr tyrosine kinase inhibitor, is used as fda approved drug in breast cancer and non-small cell lung cancer treatment. however, this drug has certain side effects and complications for which the underlying molecular mechanisms are not well understood. by systems biology based in silico analysis, we identified off-targets of gefitinib that might explain side effects of this drugs. the crystal structure of egfr-gefitinib complex was used for binding pocket similarity searches on a d ... | 2016 | 27653775 |
the response of aggregated pseudomonas putida cp1 cells to uv-c and uv-a/b disinfection. | uv radiation is a spread method used worldwide for the disinfection of water. however, much of the research on the disinfection of bacterial cells by uv has focused on planktonic cells. many bacterial cells in nature are present in clumps or aggregates, and these aggregates, which are more resistant to disinfection than their planktonic counterparts, can be problematic in engineered water systems. the current research used pseudomonas putida (p. putida) cp1, an environmental and non-pathogenic m ... | 2016 | 27655528 |
cross-talk between the aeromonas hydrophila type iii secretion system and lateral flagella system. | aeromonas hydrophila is responsible for aeromonad septicaemia in fish, and gastroenteritis and wound infections in humans. the type iii secretion system (t3ss) is utilized by aeromonads to inject protein effectors directly into host cells. one of the major genetic regulators of the t3ss in several bacterial species is the arac-like protein exsa. previous studies have suggested a link between t3ss regulation and lateral flagella expression. the aim of this study was to determine the genetic regul ... | 2016 | 27656180 |
biosynthesis of catechol melanin from glycerol employing metabolically engineered escherichia coli. | melanins comprise a chemically-diverse group of polymeric pigments whose function is related to protection against physical and chemical stress factors. these polymers have current and potential applications in the chemical, medical, electronics and materials industries. the biotechnological production of melanins offers the possibility of obtaining these pigments in pure form and relatively low cost. in this study, escherichia coli strains were engineered to evaluate the production of melanin f ... | 2016 | 27659593 |
performance of an ultraviolet mutagenetic polyphosphate-accumulating bacterium pz2 and its application for wastewater treatment in a newly designed constructed wetland. | total phosphorus (tp) removal performance and application for wastewater treatment of polyphosphate-accumulating bacteria (pab) in constructed wetlands (cws) were investigated. in this study, a novel isolated ultraviolet (uv) mutant pz2 with phosphate-accumulating ability was screened from domestic wastewater and identified as pseudomonas putida by 16s ribosomal dna (rdna) sequencing analysis. the tp removal performance of pz2 in the synthetic wastewater reached the highest of 93.95 % within 45 ... | 2017 | 27659999 |
draft genome sequence of a diazotrophic, plant growth-promoting rhizobacterium of the pseudomonas syringae complex. | we report here the draft genome sequence of pseudomonas syringae gr12-2, a nitrogen-fixing, plant growth-promoting bacterium, isolated from the rhizosphere of an arctic grass. the 6.6-mbp genome contains 5,676 protein-coding genes, including a nitrogen-fixation island similar to that in p. stutzeri. | 2016 | 27660794 |
expression of the phosphodiesterase bifa facilitating swimming motility is partly controlled by flia in pseudomonas putida kt2440. | flagella-mediated motility is an important capability of many bacteria to survive in nutrient-depleted and harsh environments. decreasing the intracellular cyclic di-gmp (c-di-gmp) level by overexpression of phosphodiesterase bifa promotes flagellar-mediated motility and induces planktonic lifestyle in pseudomonas. the mechanism that regulates expression of bifa gene was poorly studied. here we showed that expression of bifa was partly controlled by flagellar sigma factor flia (σ(28) ) in pseudo ... | 2017 | 27663176 |
transcriptomic analysis of the highly efficient oil-degrading bacterium acinetobacter venetianus rag-1 reveals genes important in dodecane uptake and utilization. | the hydrocarbonoclastic bacterium acinetobacter venetianus rag-1 has attracted substantial attention due to its powerful oil-degrading capabilities and its potential to play an important ecological role in the cleanup of alkanes. in this study, we compare the transcriptome of the strain rag-1 grown in dodecane, the corresponding alkanol (dodecanol), and sodium acetate for the characterization of genes involved in dodecane uptake and utilization. comparison of the transcriptional responses of rag ... | 2016 | 27664055 |
structural and histone binding ability characterization of the arb2 domain of a histone deacetylase hda1 from saccharomyces cerevisiae. | hda1 is the catalytic core component of the h2b- and h3- specific histone deacetylase (hdac) complex from saccharomyces cerevisiae, which is involved in the epigenetic repression and plays a crucial role in transcriptional regulation and developmental events. though the n-terminal catalytic hdac domain of hda1 is well characterized, the function of the c-terminal arb2 domain remains unknown. in this study, we determine the crystal structure of the arb2 domain from s. cerevisiae hda1 at a resolut ... | 2016 | 27665728 |
diverse bacteria with lignin degrading potentials isolated from two ranks of coal. | taking natural coal as a "seed bank" of bacterial strains able to degrade lignin that is with molecular structure similar to coal components, we isolated 393 and 483 bacterial strains from a meager lean coal sample from hancheng coalbed and a brown coal sample from bayannaoer coalbed, respectively, by using different media. statistical analysis showed that isolates were significantly more site-specific than medium-specific. of the 876 strains belonging to 27 genera in actinobacteria, firmicutes, ... | 2016 | 27667989 |
architecture of class 1, 2, and 3 integrons from gram negative bacteria recovered among fruits and vegetables. | the spread of antibiotic resistant bacteria throughout the food chain constitutes a public health concern. to understand the contribution of fresh produce in shaping antibiotic resistance bacteria and integron prevalence in the food chain, 333 antibiotic resistance gram negative isolates were collected from organic and conventionally produced fruits (pears, apples, and strawberries) and vegetables (lettuces, tomatoes, and carrots). although low levels of resistance have been detected, the bacter ... | 2016 | 27679611 |
activation of the glutamic acid-dependent acid resistance system in escherichia coli bl21(de3) leads to increase of the fatty acid biotransformation activity. | the biosynthesis of carboxylic acids including fatty acids from biomass is central in envisaged biorefinery concepts. the productivities are often, however, low due to product toxicity that hamper whole-cell biocatalyst performance. here, we have investigated factors that influence the tolerance of escherichia coli to medium chain carboxylic acid (i.e., n-heptanoic acid)-induced stress. the metabolic and genomic responses of e. coli bl21(de3) and mg1655 grown in the presence of n-heptanoic acid ... | 2016 | 27681369 |
extremophiles in an antarctic marine ecosystem. | recent attempts to explore marine microbial diversity and the global marine microbiome have indicated a large proportion of previously unknown diversity. however, sequencing alone does not tell the whole story, as it relies heavily upon information that is already contained within sequence databases. in addition, microorganisms have been shown to present small-to-large scale biogeographical patterns worldwide, potentially making regional combinations of selection pressures unique. here, we focus ... | 2016 | 27681902 |
bacterial multidrug efflux pumps: much more than antibiotic resistance determinants. | bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. with few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. in addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibi ... | 2016 | 27681908 |
stepwise simulation of 3,5-dihydro-5-methylidene-4h-imidazol-4-one (mio) biogenesis in histidine ammonia-lyase. | a 3,5-dihydro-5-methylidene-4h-imidazol-4-one (mio) electrophilic moiety is post-translationally and autocatalytically generated in homotetrameric histidine ammonia-lyase (hal) and other enzymes containing the tripeptide ala-ser-gly in a suitably positioned loop. the backbone cyclization step is identical to that taking place during fluorophore formation in green fluorescent protein from the tripeptide ser-tyr-gly, but dehydration, rather than dehydrogenation by molecular oxygen, is the reaction ... | 2016 | 27682658 |
draft genome sequences of four hospital-associated pseudomonas putida isolates. | we present here the draft genome sequences of four pseudomonas putida isolates belonging to a single clone suspected for nosocomial transmission between patients and a bronchoscope in a tertiary hospital. the four genome sequences belong to a single lineage but contain differences in their mobile genetic elements. | 2016 | 27688339 |
biosynthesis and molecular actions of specialized 1,4-naphthoquinone natural products produced by horticultural plants. | the 1,4-naphthoquinones (1,4-nqs) are a diverse group of natural products found in every kingdom of life. plants, including many horticultural species, collectively synthesize hundreds of specialized 1,4-nqs with ecological roles in plant-plant (allelopathy), plant-insect and plant-microbe interactions. numerous horticultural plants producing 1,4-nqs have also served as sources of traditional medicines for hundreds of years. as a result, horticultural species have been at the forefront of many b ... | 2016 | 27688890 |
applicability of an in-house saponin-based extraction method in bruker biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system for identification of bacterial and fungal species in positively flagged blood cultures. | we used an in-house saponin-based extraction method to evaluate the performance of the bruker biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof/ms) system for the identification of bacteria and fungi in 405 positively flagged blood culture bottles. results obtained from maldi-tof/ms were compared with those obtained using conventional phenotypic identification methods. of the 405 positively flagged blood culture bottles, 365 showed monomicrobal grow ... | 2016 | 27695442 |
physical forces shape group identity of swimming pseudomonas putida cells. | the often striking macroscopic patterns developed by motile bacterial populations on agar plates are a consequence of the environmental conditions where the cells grow and spread. parameters such as medium stiffness and nutrient concentration have been reported to alter cell swimming behavior, while mutual interactions among populations shape collective patterns. one commonly observed occurrence is the mutual inhibition of clonal bacteria when moving toward each other, which results in a distinc ... | 2016 | 27695443 |
esterase estk from pseudomonas putida mt-2: an enantioselective acetylesterase with activity for deacetylation of xylan and poly(vinylacetate). | an extracellular esterase gene estk was identified in pseudomonas putida mt-2, and was overexpressed to high levels in escherichia coli. the recombinant estk enzyme was purified and characterised kinetically against p-nitrophenyl ester and other aryl-alkyl ester substrates, and was found to be selective for hydrolysis of acetyl ester substrates, with high activity for p-nitrophenyl acetate (kcat 5.5 s(-1) , km 285 μm). recombinant estk was found to catalyse deacetylation of acetylated beech xyla ... | 2016 | 27696534 |
disruption of pseudomonas putida by high pressure homogenization: a comparison of the predictive capacity of three process models for the efficient release of arginine deiminase. | disruption of pseudomonas putida kt2440 by high-pressure homogenization in a french press is discussed for the release of arginine deiminase (adi). the enzyme release response of the disruption process was modelled for the experimental factors of biomass concentration in the broth being disrupted, the homogenization pressure and the number of passes of the cell slurry through the homogenizer. for the same data, the response surface method (rsm), the artificial neural network (ann) and the suppor ... | 2016 | 27699703 |
bacteria induce pigment formation in the basidiomycete serpula lacrymans. | basidiomycete fungi are characterized ecologically for their vital functional role in ecosystem carbon recycling and chemically for their capacity to produce a diverse array of small molecules. chromophoric natural products derived from the quinone precursor atromentin, such as variegatic acid and involutin, have been shown to function in redox cycling. yet, in the context of an inter-kingdom natural system these pigments are still elusive. here, we co-cultured the model saprotrophic basidiomyce ... | 2016 | 27699944 |
flagellin flic phosphorylation affects type 2 protease secretion and biofilm dispersal in pseudomonas aeruginosa pao1. | protein phosphorylation has a major role in controlling the life-cycle and infection stages of bacteria. proteome-wide occurrence of s/t/y phosphorylation has been reported for many prokaryotic systems. previously, we reported the phosphoproteome of pseudomonas aeruginosa and pseudomonas putida. in this study, we show the role of s/t phosphorylation of one motility protein, flic, in regulating multiple surface-associated phenomena of p. aeruginosa pao1. this is the first report of occurrence of ... | 2016 | 27701473 |
expression of the diguanylate cyclase gcba is regulated by fleq in response to cyclic di-gmp in pseudomonas putida kt2440. | cyclic di-gmp (c-di-gmp), a ubiquitous bacterial second messenger that regulates diverse cellular processes, is synthesized by diguanylate cyclase (dgc) and degraded by phosphodiesterase (pde). gcba is a well conserved dgc among pseudomonas species, and has been reported to influence biofilm formation and flagellar motility in pseudomonas fluorescens and pseudomonas aeruginosa. here we confirm the function of gcba in pseudomonas putida and reveal that expression of gcba is regulated by fleq in r ... | 2016 | 27701843 |
protein domain architectures provide a fast, efficient and scalable alternative to sequence-based methods for comparative functional genomics. | a functional comparative genome analysis is essential to understand the mechanisms underlying bacterial evolution and adaptation. detection of functional orthologs using standard global sequence similarity methods faces several problems; the need for defining arbitrary acceptance thresholds for similarity and alignment length, lateral gene acquisition and the high computational cost for finding bi-directional best matches at a large scale. we investigated the use of protein domain architectures ... | 2016 | 27703668 |
mitochondrial carriers link the catabolism of hydroxyaromatic compounds to the central metabolism in candida parapsilosis. | the pathogenic yeast candida parapsilosis metabolizes hydroxyderivatives of benzene and benzoic acid to compounds channeled into central metabolism, including the mitochondrially localized tricarboxylic acid cycle, via the 3-oxoadipate and gentisate pathways. the orchestration of both catabolic pathways with mitochondrial metabolism as well as their evolutionary origin is not fully understood. our results show that the enzymes involved in these two pathways operate in the cytoplasm with the exce ... | 2016 | 27707801 |
biotransformation of ferulic acid to vanillin in the packed bed-stirred fermentors. | we performed the biotransformation of ferulic acid to vanillin using bacillus subtilis (b. subtilis) in the stirring packed-bed reactors filled with carbon fiber textiles (cft). scanning electron microscope (sem), hplc, qrt-pcr and atp assay indicated that vanillin biotransformation is tightly related to cell growth, cellar activity and the extent of biofilm formation. the biotransformation was affected by hydraulic retention time (hrt), temperature, initial ph, stirring speed and ferulic acid c ... | 2016 | 27708366 |
engineering gram-negative microbial cell factories using transposon vectors. | the construction of microbial cell factories à la carte largely depends on specialized molecular biology and synthetic biology tools needed to reprogram bacteria for modifying their existing functions or for bestowing them with new-to-nature tasks. in this chapter, we document the use of a series of broad-host-range mini-tn5 vectors for the delivery of gene(s) into the chromosome of gram-negative bacteria and for the generation of saturated, random mutagenesis libraries for studies of gene funct ... | 2017 | 27709582 |
structural similarities and differences in h-ns family proteins revealed by the n-terminal structure of turb in pseudomonas putida kt2440. | h-ns family proteins play key roles in bacterial nucleoid compaction and global transcription. mvat homologues in pseudomonas have almost negligible amino acid sequence identity with h-ns, but can complement an hns-related phenotype of escherichia coli. here, we report the crystal structure of the n-terminal dimerization/oligomerization domain of turb, an mvat homologue in pseudomonas putida kt2440. our data identify two dimerization sites; the structure of the central dimerization site is almos ... | 2016 | 27709616 |
effect of different metal ions on the biological properties of cefadroxil. | the effect of different metal ions on the intestinal transport and the antibacterial activity of cefadroxil [(6r,7r)-7-{[(2r)-2-amino-2-(4-hydroxyphenyl)acetyl]amino}-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid] was investigated. the [(14)c]gly-sar uptake via pept1 was inhibited by zn(2+) and cu(2+) treatment in a concentration-dependent manner (ki values 107 ± 23 and 19 ± 5 μm, respectively). kinetic analysis showed that the kt of gly-sar uptake was increased 2-fold in ... | 2009 | 27713232 |
pseudomonas fluorescens f113 can produce a second flagellar apparatus, which is important for plant root colonization. | the genomic sequence of pseudomonas fluorescens f113 has shown the presence of a 41 kb cluster of genes that encode the production of a second flagellar apparatus. among 2,535 pseudomonads strains with sequenced genomes, these genes are only present in the genomes of f113 and other six strains, all but one belonging to the p. fluorescens cluster of species, in the form of a genetic island. the genes are homologous to the flagellar genes of the soil bacterium azotobacter vinelandii. regulation of ... | 2016 | 27713729 |
genome-based genetic tool development for bacillus methanolicus: theta- and rolling circle-replicating plasmids for inducible gene expression and application to methanol-based cadaverine production. | bacillus methanolicus is a thermophilic methylotroph able to overproduce amino acids from methanol, a substrate not used for human or animal nutrition. based on our previous rna-seq analysis a mannitol inducible promoter and a putative mannitol activator gene mtlr were identified. the mannitol inducible promoter was applied for controlled gene expression using fluorescent reporter proteins and a flow cytometry analysis, and improved by changing the -35 promoter region and by co-expression of the ... | 2016 | 27713731 |
identification and characterization of an aeromonas hydrophila oligopeptidase gene pepf negatively related to biofilm formation. | bacterial biofilms are involved in adaptation to complex environments and are responsible for persistent bacterial infections. biofilm formation is a highly complex process during which multifarious genes work together regularly. in this study, we screened the ez-tn5 transposon mutant library to identify genes involved in biofilm formation of aeromonas hydrophila. a total of 24 biofilm-associated genes were identified, the majority of which encoded proteins related to cell structure, transcripti ... | 2016 | 27713736 |
engineering of tm1459 from thermotoga maritima for increased oxidative alkene cleavage activity. | oxidative cleavage of alkenes is a widely employed process allowing oxyfunctionalization to corresponding carbonyl compounds. recently, a novel biocatalytic oxidative alkene cleavage activity on styrene derivatives was identified in tm1459 from thermotoga maritima. in this work we engineered the enzyme by site-saturation mutagenesis of active site amino acids to increase its activity and to broaden its substrate scope. a high-throughput assay for the detection of the ketone products was successf ... | 2016 | 27713741 |
characterization of four new distinct ω-transaminases from pseudomonas putida nbrc 14164 for kinetic resolution of racemic amines and amino alcohols. | four uncharacterized ω-transaminases (ωtas) from pseudomonas putida nbrc 14164 have been identified and cloned from the pool of fully sequenced genomes. the genes were functionally expressed in escherichia coli bl21, and the enzymes were purified and characterized. four tas showed highly (s)-selective ωta activity and converted (s)-α-methylbenzylamine and pyruvate to acetophenone and l-ala. the maximum activity of cloned enzymes was in the ph range of 8.0-8.5 (pp36420), 8.5-9.5 (pp21050), 9.0-9. ... | 2017 | 27714638 |
toxicity evaluation of selected ammonium-based ionic liquid forms with mcpp and dicamba moieties on pseudomonas putida. | combination of the hydrophilic herbicidal anion with hydrophobic, antimicrobial ammonium cation allows to obtain compounds in ionic liquid form with better properties then conventional herbicides. both cation and anion can be modified by selection of herbicide and the length of alkyl chains in cation structure. however the knowledge of their potential toxic effects are still limited. furthermore, the relation between hydrophobicity associated with the length of alkyl chains and toxicity for ioni ... | 2017 | 27716584 |
identification and validation of novel small proteins in pseudomonas putida. | small proteins of 50 amino acids or less have been understudied due to difficulties that impede their annotation and detection. in order to obtain information on small open reading frames (sorfs) in pseudomonas putida, bioinformatic and proteomic approaches were used to identify putative sorfs in the well-characterized strain kt2440. a plasmid-based system was established for sorf validation, enabling expression of c-terminal sequential peptide affinity tagged variants and their detection via pr ... | 2016 | 27717237 |
metabolic engineering of corynebacterium glutamicum for enhanced production of 5-aminovaleric acid. | 5-aminovaleric acid (5ava) is an important five-carbon platform chemical that can be used for the synthesis of polymers and other chemicals of industrial interest. enzymatic conversion of l-lysine to 5ava has been achieved by employing lysine 2-monooxygenase encoded by the davb gene and 5-aminovaleramidase encoded by the dava gene. additionally, a recombinant escherichia coli strain expressing the davb and dava genes has been developed for bioconversion of l-lysine to 5ava. to use glucose and xy ... | 2016 | 27717386 |
robust at-line quantification of poly(3-hydroxyalkanoate) biosynthesis by flow cytometry using a bodipy 493/503-syto 62 double-staining. | poly(3-hydroxyalkanoates) (phas) are bio-based and biodegradable polyesters which have been considered as a promising alternative to petrol-based plastics. their bacterial production is a dynamic process in which intracellular polymerization and depolymerization are closely linked and depend on the availability of carbon substrates and other nutrients. these dynamics require a fast and quantitative method to determine the optimal harvest-time of pha containing cells or to adjust carbon supply. i ... | 2016 | 27720900 |
highly efficient and stable novel nanobiohybrid catalyst to avert 3,4-dihydroxybenzoic acid pollutant in water. | the present study reported for the first time covalent immobilization of protocatechuate 3,4-dioxygenase (3,4-pod) onto functionalized multi-walled carbon nanotubes (f-mwcnt) for degrading the toxic 3,4-dihydroxybenzoic acid (3,4-dhba) pollutant in water. the f-mwcnts had a maximum 3,4-pod loading of 1060 μg/mg. immobilized 3,4 pod had 44% of relative structural changes to its free configurations. nevertheless, >90% of relative activity and about 50% of catalytic efficiency were retained to the ... | 2016 | 27721429 |
triclosan in water, implications for human and environmental health. | triclosan (tcs) is a broad spectrum antibacterial agent present as an active ingredient in some personal care products such as soaps, toothpastes and sterilizers. it is an endocrine disrupting compound and its increasing presence in water resources as well as in biosolid-amended soils used in farming, its potential for bioaccumulation in fatty tissues and toxicity in aquatic organisms are a cause for concern to human and environmental health. tcs has also been detected in blood, breast milk, uri ... | 2016 | 27722057 |
molecular detection of acanthamoeba spp., naegleria fowleri and vermamoeba (hartmannella) vermiformis as vectors for legionella spp. in untreated and solar pasteurized harvested rainwater. | legionella spp. employ multiple strategies to adapt to stressful environments including the proliferation in protective biofilms and the ability to form associations with free-living amoeba (fla). the aim of the current study was to identify legionella spp., acanthamoeba spp., vermamoeba (hartmannella) vermiformis and naegleria fowleri that persist in a harvested rainwater and solar pasteurization treatment system. | 2016 | 27724947 |
comprehensive genomic and phenotypic metal resistance profile of pseudomonas putida strain s13.1.2 isolated from a vineyard soil. | trace metals are required in many cellular processes in bacteria but also induce toxic effects to cells when present in excess. as such, various forms of adaptive responses towards extracellular trace metal ions are essential for the survival and fitness of bacteria in their environment. a soil pseudomonas putida, strain s13.1.2 has been isolated from french vineyard soil samples, and shown to confer resistance to copper ions. further investigation revealed a high capacity to tolerate elevated c ... | 2016 | 27730570 |
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 |
cpxr activates mexab-oprm efflux pump expression and enhances antibiotic resistance in both laboratory and clinical nalb-type isolates of pseudomonas aeruginosa. | resistance-nodulation-division (rnd) efflux pumps are responsible for multidrug resistance in pseudomonas aeruginosa. in this study, we demonstrate that cpxr, previously identified as a regulator of the cell envelope stress response in escherichia coli, is directly involved in activation of expression of rnd efflux pump mexab-oprm in p. aeruginosa. a conserved cpxr binding site was identified upstream of the mexa promoter in all genome-sequenced p. aeruginosa strains. cpxr is required to enhance ... | 2016 | 27736975 |
investigation into the mode of phosphate activation in the 4-hydroxy-4-methyl-2-oxoglutarate/4-carboxy-4-hydroxy-2-oxoadipate aldolase from pseudomonas putida f1. | the 4-hydroxy-4-methyl-2-oxoglutarate (hmg)/4-carboxy-4-hydroxy-2-oxoadipate (cha) aldolase is the last enzyme of both the gallate and protocatechuate 4,5-cleavage pathways which links aromatic catabolism to central cellular metabolism. the enzyme is a class ii, divalent metal dependent, aldolase which is activated in the presence of inorganic phosphate (pi), increasing its turnover rate >10-fold. this phosphate activation is unique for a class ii aldolase. the aldolase pyruvate methyl proton ex ... | 2016 | 27741265 |
structural basis for the transcriptional repressor nicr2 in nicotine degradation from pseudomonas. | nicotine is an environmental toxicant in tobacco wastes, imposing severe hazards for the health of human and other mammalians. nicr2, a tetr-like repressor from pseudomonas putida s16, plays a critical role in regulating nicotine degradation. here, we determined the crystal structures of nicr2 and its complex with the inducer 6-hydroxy-3-succinoyl-pyridine (hsp). the n-terminal domain of nicr2 contains a conserved helix-turn-helix (hth) dna-binding motif, while the c-terminal domain contains a c ... | 2017 | 27741553 |
host range of the conjugative transfer system of incp-9 naphthalene-catabolic plasmid nah7 and characterization of its orit region and relaxase. | nah7 and pww0 from gammaproteobacterial pseudomonas putida strains are incp-9 conjugative plasmids that carry the genes for degradation of naphthalene and toluene, respectively. although such genes on these plasmids are well-characterized, experimental investigation of their conjugation systems remains at a primitive level. to clarify these conjugation systems, in this study, we investigated the nah7-encoded conjugation system by (i) analyzing the origin of its conjugative transfer (orit)-contai ... | 2017 | 27742684 |
plant drought tolerance enhancement by trehalose production of desiccation-tolerant microorganisms. | a collection of desiccation-tolerant xeroprotectant-producing microorganisms was screened for their ability to protect plants against drought, and their role as plant growth-promoting rhizobacteria was investigated in two different crops (tomato and pepper). the most commonly described biochemical mechanisms for plant protection against drought by microorganisms including the production of phytohormones, antioxidants and xeroprotectants were analyzed. in particular, the degree of plant protectio ... | 2016 | 27746776 |