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Bioresource Technology Nov 2020The main aim of this work was to study the allethrin binding interactions with esterase and its bioremediation potential using an isolated bacterial strain CW7,...
The main aim of this work was to study the allethrin binding interactions with esterase and its bioremediation potential using an isolated bacterial strain CW7, identified as Pseudomonas nitroreducens. The degradation conditions with strain CW7 were optimized using response surface methodology at pH 7.0, a temperature of 32 °C, and an inocula concentration of 150 mg·L, with 96% allethrin degradation observed over 7 days. The kinetic parameters q, K and K were calculated to be 0.512 day, 4.97 mg·L and 317.13 mg·L, respectively. Nine intermediate metabolites were identified after analysing the degradation products by gas chromatography-mass spectrometry. Strain CW7 effectively degraded a wide variety of pyrethroids as a carbon source. Molecular modeling, docking, and enzyme kinetics were used to investigate the binding pocket of the esterase containing amino acids such as alanine, arginine, valine, proline, cysteine, glycine, isoleucine, phenylalanine, serine, asparagine, and threonine, which play active roles in allethrin degradation.
Topics: Alanine; Allethrins; Arginine; Biodegradation, Environmental; Esterases; Glutamates; Histidine; Leucine; Lysine; Methionine; Pseudomonas; Serine; Tyrosine
PubMed: 32707504
DOI: 10.1016/j.biortech.2020.123845 -
Biotechnology Reports (Amsterdam,... Dec 2021The mechanisms of tolerance to heavy metals used by some microorganisms identified by bioprospection processes are useful for the development and implementation of...
The mechanisms of tolerance to heavy metals used by some microorganisms identified by bioprospection processes are useful for the development and implementation of bioremediation strategies for contaminated environments with high toxic load caused by heavy metals. A total of seven native microbial isolates were obtained from wastewater bodies from an industrial zone in the municipality of Girardota, Antioquia, Colombia. Subsequently, they were selected to evaluate their lead tolerance capacity at different concentrations. In addition, some parameters were determined, such as the capacity to produce exopolysaccharides and their biosorption to understand potential mechanisms associated to lead tolerance. According to the biocehemical test (Vitek) and the molecular analysis of sequences of 16S rDNA, bacterial were identified as , and . We determined that the seven isolates had the capacity to tolerate concentrations higher than 50 mg/ml of lead, and that the concentration and exposure time (40 h) to this metal significantly affect the spp. isolates. Statistically significant differences were detected ( < 0.05) in the production of the exopolysaccharide (EPS) among the isolates. (P16) was the strain with the maximum absorbance exopolysaccharide measured. We evidenced that (P14) and (P20) have 80% capacity to biosorber lead using live mass (minimum range from 80.9% to 87%). It is suggested that the tolerance to lead exhibited by the environmental isolates of spp. can be attributed to the production of exopolysaccharides and biosorption, which are protection factors for its survival in contaminated places. Finally, it was determined that the adsorption measured from dead biomass was significant ( < 0.05) from 40 h of exposure to metal (Average 182.2 ± 7). We generated new knowledge about the potential use of the spp. genus to bioremediate affluent contaminated with heavy metals.
PubMed: 34765463
DOI: 10.1016/j.btre.2021.e00685 -
International Journal of Molecular... Nov 2022The B12-producing strains DSM 1650 and sp. CCUG 2519 (both formerly ), with the most distributed pathway among bacteria for exogenous choline/betaine utilization, are...
The B12-producing strains DSM 1650 and sp. CCUG 2519 (both formerly ), with the most distributed pathway among bacteria for exogenous choline/betaine utilization, are promising recombinant hosts for the endogenous production of B12 precursor betaine by direct methylation of bioavailable glycine or non-proteinogenic -alanine. Two plasmid-based de novo betaine pathways, distinguished by their enzymes, have provided an expression of the genes encoding for -methyltransferases of the halotolerant cyanobacterium or plant to synthesize the internal glycine betaine or -alanine betaine, respectively. These betaines equally allowed the recombinant pseudomonads to grow effectively and to synthesize a high level of cobalamin, as well as to increase their protective properties against abiotic stresses to a degree comparable with the supplementation of an exogenous betaine. Both de novo betaine pathways significantly enforced the protection of bacterial cells against lowering temperature to 15 °C and increasing salinity to 400 mM of NaCl. However, the expression of the single plant-derived gene for the -alanine-specific -methyltransferase additionally increased the effectiveness of exogenous glycine betaine almost twofold on cobalamin biosynthesis, probably due to the ' ability to use two independent pathways, their own choline/betaine pathway and the plant -alanine betaine biosynthetic pathway.
Topics: Betaine; Choline; Pseudomonas; Stress, Physiological; Methyltransferases; beta-Alanine; Vitamin B 12
PubMed: 36430408
DOI: 10.3390/ijms232213934 -
Heliyon Jun 2023Polystyrene is a plastic that leads to environmental pollution. In particular, expanded polystyrene is very light and takes up much space, causing additional...
OBJECTIVES
Polystyrene is a plastic that leads to environmental pollution. In particular, expanded polystyrene is very light and takes up much space, causing additional environmental problems. The aim of this study was to isolate new symbiotic bacteria which degraded polystyrene from mealworms.
METHODS
The population of polystyrene degrading bacteria was increased by enrichment culture of intestinal bacteria from mealworms with polystyrene as a sole carbon source. The degradation activity of isolated bacteria was evaluated by morphological change of micro-polystyrene particles and the surface change of polystyrene films.
RESULTS
Eight isolated species (, , , , , , , and ) were identified that degrade polystyrene.
CONCLUSION
Bacterial identification shows that a broad spectrum of bacteria decomposing polystyrene coexists in the intestinal tract of mealworms.
PubMed: 37426801
DOI: 10.1016/j.heliyon.2023.e17352 -
International Journal of Systematic and... Jan 2024Five strains of two novel species were isolated from the wastewater treatment systems of a pharmaceutical factory located in Zhejiang province, PR China. Strains ZM22...
Five strains of two novel species were isolated from the wastewater treatment systems of a pharmaceutical factory located in Zhejiang province, PR China. Strains ZM22 and Y6 were identified as belonging to a potential novel species of the genus , whereas strains ZM23, ZM24 and ZM25 were identified as belonging to a novel species of the genus . These strains were characterized by polyphasic approaches including 16S rRNA gene analysis, multi-locus sequence analysis, average nucleotide identity (ANI), DNA-DNA hybridization (DDH), physiological and biochemical tests, as well as chemotaxonomic analysis. Genome-based phylogenetic analysis further confirmed that strains ZM22 and Y6 form a distinct clade closely related to ATCC 11996 and DSM 17888. Strains ZM23, ZM24 and ZM25 were grouped as a separate clade closely related to DSM 14399 and LAM1902. The orthoANI and DDH results indicated that strains ZM22 and Y6 belong to the same species. In addition, genomic DNA fingerprinting demonstrated that these strains do not originate from a single clone. The same results were observed for strains ZM23, ZM24 and ZM25. Strains ZM22 and Y6 were resistant to multiple antibiotics, whereas strains ZM23, ZM24 and ZM25 were able to degrade an emerging pollutant, triclosan. The phylogenetic, physiological and biochemical characteristics, as well as chemotaxonomy, allowed these strains to be distinguished from their genus, and we therefore propose the names sp. nov. (type strain ZM22=MCCC 1K08496=KCTC 82561) and sp. nov. (type strain ZM23=MCCC 1K08497=JCM 36056), respectively.
Topics: Bacterial Typing Techniques; Base Composition; Comamonas; DNA, Bacterial; Fatty Acids; Phylogeny; Pseudomonas; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Drug Industry; Water Purification
PubMed: 38190241
DOI: 10.1099/ijsem.0.006222 -
Bioresource Technology Nov 2019The indiscriminate use of pesticides leads to serious food safety and toxicity issues and threatens the environment and biodiversity. Pseudomonas nitroreducens AR-3...
The indiscriminate use of pesticides leads to serious food safety and toxicity issues and threatens the environment and biodiversity. Pseudomonas nitroreducens AR-3 isolated from pesticide contaminated agricultural soil removed 97% of chlorpyrifos (CP) in just 8 h, in a mineral salt medium (MSM) containing glucose (1.0 g/L) and yeast extract (0.5 g/L) at 30 °C and 2% (v/v) inoculum when challenged with 100 mg/L CP. 3, 5, 6-trichloro 2-pyridinol (TCP), the degradation product of CP was detected only in low levels, indicating its further degradation. Organophosphate hydrolase (OPH), the enzyme considered responsible for CP degradation, had an intracellular localization. Crude OPH (1 mg/ml) removed 42% of 100 mg/L chlorpyrifos in just 2 h, indicating a rapid rate of degradation. Ultra-fast degradation of chlorpyrifos with an inducible OPH marks the potential of P. nitroreducens AR-3 for bioremediation of organophosphates. The strain AR-3 has the fastest rate of organophosphate degradation reported till date among Pseudomonads.
Topics: Biodegradation, Environmental; Chlorpyrifos; Pesticides; Pseudomonas
PubMed: 31466023
DOI: 10.1016/j.biortech.2019.122025 -
Journal of Hazardous Materials Jan 2017Effect of biosurfactant on biodegradation of pyrene was studied using a microbial consortium predominantly composed of Pseudomonas viridiflava (49.5%) and Pseudomonas...
Effect of biosurfactant on biodegradation of pyrene was studied using a microbial consortium predominantly composed of Pseudomonas viridiflava (49.5%) and Pseudomonas nitroreducens (32.5%) in a batch experiment containing lipopeptidic biosurfactant, produced by Paenibacillus dendritiformis CN5 strain, and mineral salt medium. The results showed that the lipopeptide at 600 and 300mgL enhanced pyrene degradation to 83.5% and 67% respectively in 24days compared to 16% degradation in its absence. However degradation of pyrene was reduced to 57% as the lipopeptide supplementation was raised to 900mgL. This demonstrates that the biodegradation of pyrene was found to increase with an increase in the lipopeptide concentration up to a threshold level. The experimental data were fitted to the logistic kinetic model which provided best fit with a coefficient of determination (R) values≥0.97. Maximum specific growth rate, μ of 0.97 and 0.69d were achieved in the 600 and 300mgL lipopeptide amendments in comparison to 0.54d in the unamended one. The carrying capacity, X increased 4.4-fold in 600mgL lipopeptide supplemented samples in comparison to its absence. Generally the lipopeptide showed potential application in improving bioremediation of polycyclic aromatic hydrocarbons contaminated environmental media.
Topics: Biodegradation, Environmental; Environmental Pollutants; Lipopeptides; Microbial Consortia; Paenibacillus; Pseudomonas; Pyrenes; Surface-Active Agents
PubMed: 27627697
DOI: 10.1016/j.jhazmat.2016.08.035 -
AoB PLANTS Apr 2019Gametophytes of the fern develop into either hermaphrodites or males. As hermaphrodites develop, they secrete antheridiogen, or A, into the environment, inducing male...
Gametophytes of the fern develop into either hermaphrodites or males. As hermaphrodites develop, they secrete antheridiogen, or A, into the environment, inducing male development in undifferentiated gametophytes. Hermaphrodites are composed of archegonia, antheridia, rhizoids and a notch meristem, while males consist of antheridia and rhizoids. Much of the research on sexual and morphological development concerns gametophytes grown in sterile environments. Using biochemical and molecular techniques we identify a soil bacterium and explore its effects on sexual and rhizoid development. Hermaphrodite and male gametophytes were exposed to this bacterium and the effects on sexual development, rhizoid length and rhizoid number were explored. The bacterium was identified as a pseudomonad, . Gametophytes grown in the presence of the pseudomonad were more likely to develop into hermaphrodites across all gametophyte densities. Across all gametophyte sizes, hermaphrodites had rhizoids that were 2.95× longer in the presence of the pseudomonad while males had rhizoids that were 2.72× longer in the presence of the pseudomonad. Both hermaphrodite and male gametophytes developed fewer rhizoids in the presence of the pseudomonad. Control hermaphrodites produced 1.23× more rhizoids across all gametophyte sizes. For male gametophytes grown in the absence of the pseudomonad, the rate of increase in the number of rhizoids was greater with increasing size in the control than the rate of increase in males grown in the presence of the pseudomonad. The pseudomonad may be acting on gametophyte sexual development via several potential mechanisms: degradation of A, changes in nutrient availability or phytohormone production. The pseudomonad may also increase rhizoid number through production of phytohormones or changes in nutrient availability.
PubMed: 31019671
DOI: 10.1093/aobpla/plz012 -
Canadian Journal of Microbiology Dec 2018We report an investigation of microbially induced carbonate precipitation by seven indigenous bacteria isolated from a landfill in China. Bacterial strains were cultured...
We report an investigation of microbially induced carbonate precipitation by seven indigenous bacteria isolated from a landfill in China. Bacterial strains were cultured in a medium supplemented with 25 mmol/L calcium chloride and 333 mmol/L urea. The experiments were carried out at 30 °C for 7 days with agitation by a shaking table at 130 r/min. Scanning electron microscopic and X-ray diffraction analyses showed variations in calcium carbonate polymorphs and mineral composition induced by all bacterial strains. The amount of carbonate precipitation was quantified by titration. The amount of carbonate precipitated in the medium varied among isolates, with the lowest being Bacillus aerius rawirorabr15 (LC092833) precipitating around 1.5 times more carbonate per unit volume than the abiotic (blank) solution. Pseudomonas nitroreducens szh_asesj15 (LC090854) was found to be the most efficient, precipitating 3.2 times more carbonate than the abiotic solution. Our results indicate that bacterial carbonate precipitation occurred through ureolysis and suggest that variations in carbonate crystal polymorphs and rates of precipitation were driven by strain-specific differences in urease expression and response to the alkaline environment. These results and the method applied provide benchmarking and screening data for assessing the bioremediation potential of indigenous bacteria for containment of contaminants in landfills.
Topics: Bacteria; Biomineralization; Calcium Carbonate; Crystallization; Hydrogen-Ion Concentration; Waste Disposal Facilities; X-Ray Diffraction
PubMed: 30148972
DOI: 10.1139/cjm-2018-0254 -
Scientific Reports May 2019Bacteria in the environment play a major role in the degradation of widely used man-made recalcitrant organic compounds. Pseudomonas nitroreducens TX1 is of special...
Bacteria in the environment play a major role in the degradation of widely used man-made recalcitrant organic compounds. Pseudomonas nitroreducens TX1 is of special interest because of its high efficiency to remove nonionic ethoxylated surfactants. In this study, a novel approach was demonstrated by a bacterial enzyme involved in the formation of radicals to attack ethoxylated surfactants. The dihydrolipoamide dehydrogenase was purified from the crude extract of strain TX1 by using octylphenol polyethoxylate (OPEO) as substrate. The extent of removal of OPEOs during the degradation process was conducted by purified recombinant enzyme from E. coli BL21 (DE3) in the presence of the excess of metal mixtures (Mn, Mg, Zn, and Cu). The metabolites and the degradation rates were analyzed and determined by liquid chromatography-mass spectrometry. The enzyme was demonstrated to form Fenton reagent in the presence of an excess of metals. Under this in vitro condition, it was shown to be able to shorten the ethoxylate chains of OPEO. After 2 hours of reaction, the products obtained from the degradation experiment revealed a prominent ion peak at m/z = 493.3, namely the ethoxylate chain unit is 6 (OPEO) compared to OPEO (m/z = 625.3), the main undegraded surfactant in the no enzyme control. It revealed that the concentration of OPEO and OPEO decreased by 90% and 40% after 4 hours, respectively. The disappearance rates for the OPEO homologs correlated to the length of the exothylate chains, suggesting it is not a specific enzymatic reaction which cleaves one unit by unit from the end of the ethoxylate chain. The results indicate the diverse and novel strategy by bacteria to catabolize organic compounds by using existing housekeeping enzyme(s).
Topics: Bacterial Proteins; Chromatography, Liquid; Copper; Dihydrolipoamide Dehydrogenase; Escherichia coli; Magnesium; Manganese; Mass Spectrometry; Phenols; Pseudomonas; Surface-Active Agents; Zinc
PubMed: 31048711
DOI: 10.1038/s41598-019-43266-8