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Journal of Natural Products Nov 2022The secondary metabolite pseudopyronine B, isolated from P33, was biotransformed by human P450 enzymes, heterologously expressed in the fission yeast . Small-scale...
The secondary metabolite pseudopyronine B, isolated from P33, was biotransformed by human P450 enzymes, heterologously expressed in the fission yeast . Small-scale studies confirmed that both CYP4F2 and CYP4F3A were capable of oxidizing the substrate, with the former achieving a higher yield. In larger-scale studies using CYP4F2, three new oxidation products were obtained, the structures of which were elucidated by UV-vis, 1D and 2D NMR, and HR-MS spectroscopy. These corresponded to hydroxylated, carboxylated, and ester derivatives (-) of pseudopyronine B, all of which had been oxidized exclusively at the ω-position of the C-6 alkyl chain. homology modeling experiments highlighted key interactions between oxygen atoms of the pyrone ring and two serine residues and a histidine residue of CYP4F2, which hold the substrate in a suitable orientation for oxidation at the terminus of the C-6 alkyl chain. Additional modeling studies with all three pseudopyronines revealed that the seven-carbon alkyl chain of pseudopyronine B was the perfect length for oxidation, with the terminal carbon lying close to the heme iron. The antibacterial activity of the substrates and three oxidation products was also assessed, revealing that oxidation at the ω-position removes all antimicrobial activity. This study both increases the range of known substrates for human CYF4F2 and CYP4F3A enzymes and demonstrates their utility in producing additional natural product derivatives.
Topics: Humans; Anti-Bacterial Agents; Biotransformation; Cytochrome P-450 Enzyme System; Cytochrome P450 Family 4; Hydroxylation; Oxidation-Reduction; Pyrones; Schizosaccharomyces
PubMed: 36327116
DOI: 10.1021/acs.jnatprod.2c00616 -
Microbiology Resource Announcements Dec 2023The P 5(3) strain is a potential degrader of persistent perfluorinated pollutants, particularly C-C perfluorinated acids. The genome of the strain has been fully...
The P 5(3) strain is a potential degrader of persistent perfluorinated pollutants, particularly C-C perfluorinated acids. The genome of the strain has been fully sequenced. It consists of a chromosome with a length of 5,676,241 base pairs and a G-C content of 64.38%.
PubMed: 37955621
DOI: 10.1128/MRA.00839-23 -
Frontiers in Microbiology 2022K17, an indigenous and heterotrophic nitrifying-aerobic denitrifying bacterium, was isolated from the soil of a weathered crust elution-deposited rare earth ore leaching...
K17, an indigenous and heterotrophic nitrifying-aerobic denitrifying bacterium, was isolated from the soil of a weathered crust elution-deposited rare earth ore leaching site in Longnan County, China. Strain K17 was identified as . In this study, the morphological characteristics of strain K17 were observed and the optimal ammonia nitrogen removal conditions for the strain were studied using a single-factor experiment. Key enzyme activities were determined, and we also explored the ammonia nitrogen removal process of strain K17 on simulated leaching liquor of the rare earth element leaching site. Based on the determination of ammonia nitrogen removal and enzyme activity, it was found that strain K17 has both heterotrophic nitrifying and aerobic denitrifying activities. In addition, single-factor experiments revealed that the most appropriate carbon source for strain K17 was sodium citrate with a C/N ratio of 10 and an initial NH -N concentration of 100 mg/l. Furthermore, the optimal initial pH and rotation speed were 7 and 165 r/min, respectively. Under optimal conditions, the ammonia nitrogen removal efficiency of strain K17 was greater than 95%. As an indigenous bacterium, strain K17 has great potential for treating residual ammonium leaching solutions from rare earth element leaching sites.
PubMed: 35756011
DOI: 10.3389/fmicb.2022.905409 -
Biodegradation Aug 2019Biosurfactants are one among the best alternative for synthetic surfactants that are exploited by many researchers. Several agro wastes help to reduce the cost...
Biosurfactants are one among the best alternative for synthetic surfactants that are exploited by many researchers. Several agro wastes help to reduce the cost biosurfactants by being renewable and economical. The present research focuses on the biosurfactant production from Pseudomonas mosselii utilizing Parthenium hysterophorus as a relatively cheap substrate. P. hysterophorus being a hazardous weed, its eradication is quite tedious. So, the utilization of the weed for useful purposes serves as a choice to overcome the problems posed by the weed. In the study, this weed has been successfully utilized as a substrate and the optimized fermentative production of biosurfactant was done. From one-factor-at a-time analysis it was known that the substrate level of 3% incubation time of 96 h, pH 6.0, temperature 35 °C, glucose and yeast extract was found to be the best C and N sources for a high yield. The extracted biosurfactant was partially purified and characterized using FTIR. The biosurfactant produced from the weed could help to render the milestone for distinct biomedical and other applications.
Topics: Biodegradation, Environmental; Fermentation; Plant Extracts; Surface-Active Agents; Temperature
PubMed: 31104258
DOI: 10.1007/s10532-019-09878-7 -
Frontiers in Microbiology 2021is a diverse genus of Gammaproteobacteria with increasing novel species exhibiting versatile trains including antimicrobial and insecticidal activity, as well as plant...
is a diverse genus of Gammaproteobacteria with increasing novel species exhibiting versatile trains including antimicrobial and insecticidal activity, as well as plant growth-promoting, which make them well suited as biocontrol agents of some pathogens. Here we isolated strain 1257 that exhibited strong antagonistic activity against two pathovars of , especially . pv. () responsible for the bacterial leaf streak (BLS) in rice. The phylogenetic, genomic, physiological, and biochemical characteristics support that strain 1257 is a representative of a novel species that is most closely related to the entomopathogenic bacterium We propose to name it sp. nov. Comparative genomics analyses showed that 1257 possesses most of the central metabolic genes of two closely related strains L48 and CFML 90-83, as well as a set of genes encoding the type IV pilus system, suggesting its versatile metabolism and motility properties. Some features, such as insecticidal toxins, phosphate solubilization, indole-3-acetic acid, and phenylacetic acid degradation, were disclosed. Genome-wide random mutagenesis revealed that the non-ribosomal peptide catalyzed by LgrD may be a major active compound of 1257 against RS105, as well as the critical role of the carbamoyl phosphate and the pentose phosphate pathway that control the biosynthesis of this target compound. Our findings demonstrate that 1257 could effectively inhibit the growth and migration of in rice tissue to prevent the BLS disease. To our knowledge, this is the first report of a novel species that displays a strong antibacterial activity against . The results suggest that the strain could be a promising biological control agent for BLS.
PubMed: 34803984
DOI: 10.3389/fmicb.2021.759536 -
Microbiology Spectrum Aug 2022Asian rice is one of the most important crops because it is a staple food for almost half of the world's population. To have production of rice keep pace with a growing...
Asian rice is one of the most important crops because it is a staple food for almost half of the world's population. To have production of rice keep pace with a growing world population, it is anticipated that the use of fertilizers will also need to increase, which may cause environmental damage through runoff impacts. An alternative strategy to increase crop yield is the use of plant growth-promoting bacteria. Thousands of microbial species can exist in association with plant roots and shoots, and some are critical to the plant's survival. We isolated 140 bacteria from two distantly related rice accessions and investigated whether their impact on the growth of four different rice accessions. The bacterial isolates were screened for their ability to solubilize phosphate, a known plant growth-promoting characteristic, and 25 isolates were selected for further analysis. These 25 phosphate-solubilizing isolates were also able to produce other potentially growth-promoting factors. Five of the most promising bacterial isolates were chosen for whole-genome sequencing. Four of these bacteria, isolates related to Pseudomonas mosselii, a sp., Paenibacillus rigui, and Paenibacillus graminis, improved root and shoot growth in a rice genotype-dependent manner. This indicates that while bacteria have several known plant growth-promoting functions, their effects on growth parameters are rice genotype dependent and suggest a close relationship between plants and their microbial partners. In this study, endophytic bacterial isolates from roots and shoots of two distantly related rice accessions were characterized phenotypically and genotypically. From the isolated bacterial species, five of the most promising plant growth-promoting bacteria were selected to test their abilities to enhance growth of the four rice accessions. Interestingly, plant growth enhancement was both bacterial isolate specific and plant genotype specific. However, the positive interactions between plant and bacteria could not easily be predicted because rice growth-promoting bacteria isolated from their host plants did not necessarily stimulate growth of their own host.
Topics: Genotype; Oryza; Phosphates; Plant Roots
PubMed: 35862989
DOI: 10.1128/spectrum.02787-21 -
Bioresource Technology Sep 2023This study was designed to develop a cellulase-producing bacterial consortium (CBC) from wood-feeding termites that could effectively degrade willow sawdust (WSD) and...
This study was designed to develop a cellulase-producing bacterial consortium (CBC) from wood-feeding termites that could effectively degrade willow sawdust (WSD) and consequently enhance methane production. The bacterial strains Shewanella sp. SSA-1557, Bacillus cereus SSA-1558, and Pseudomonas mosselii SSA-1568 exhibited significant cellulolytic activity. Their CBC consortium showed positive effects on cellulose bioconversion, resulting in accelerated WSD degradation. After nine days of pretreatment, the WSD had lost 63%, 50%, and 28% of its cellulose, hemicellulose, and lignin, respectively. The hydrolysis rate of treated WSD (352 mg/g) was much higher than that of untreated WSD (15.2 mg/g). The highest biogas production (66.1 NL/kg VS) with 66% methane was observed in the anaerobic digester M-2, which contained a combination of pretreated WSD and cattle dung in a 50/50 ratio. The findings will enrich knowledge for the development of cellulolytic bacterial consortia from termite guts for biological wood pretreatment in lignocellulosic anaerobic digestion biorefineries.
Topics: Animals; Cattle; Isoptera; Salix; Wood; Cellulase; Lignin; Cellulose; Bacteria; Biofuels; Methane; Anaerobiosis
PubMed: 37244303
DOI: 10.1016/j.biortech.2023.129232 -
ACS Omega Apr 2020The unregulated discharge of nanoparticles (NPs) from various nanotechnology industries into the environment is expected to alter the composition and physiological...
Destruction of Cell Topography, Morphology, Membrane, Inhibition of Respiration, Biofilm Formation, and Bioactive Molecule Production by Nanoparticles of Ag, ZnO, CuO, TiO, and AlO toward Beneficial Soil Bacteria.
The unregulated discharge of nanoparticles (NPs) from various nanotechnology industries into the environment is expected to alter the composition and physiological functions of soil microbiota. Considering this knowledge gap, the impact of five NPs (Ag, ZnO, CuO, AlO, and TiO) differing in size and morphology on growth behavior and physiological activity of , , , and were investigated. Various biochemical and microscopic approaches were adopted. Interestingly, all bacterial strains were found sensitive to Ag-NPs and ZnO-NPs but showed tolerance toward CuO, AlO, and TiO-NPs. The loss of cellular respiration due to NPs was coupled with a reduction in population size. ZnO-NPs at 387.5 μg mL had a maximum inhibitory impact on and reduced its population by 72%. Under Ag-NP stress, the reduction in IAA secretion by bacterial strains followed the order (74%) > (63%) > (49%). The surface of bacterial cells had small- or large-sized aggregates of NPs. Also, numerous gaps, pits, fragmented, and disorganized cell envelopes were visible. Additionally, a treated cell surface appeared corrugated with depressions and alteration in cell length and a strong heterogeneity was noticed under atomic force microscopy (AFM). For instance, NPs induced cell roughness for followed the order 12.6 nm (control) > 58 nm (Ag-NPs) > 41 nm (ZnO-NPs). TEM analysis showed aberrant morphology, cracking, and disruption of the cell envelope with extracellular electron-dense materials. Increased permeability of the inner cell membrane caused cell death and lowered EPS production. Ag-NPs and ZnO-NPs also disrupted the surface adhering ability of bacteria, which varied with time and concentration of NPs. Conclusively, a plausible mechanism of NP toxicity to bacteria has been proposed to understand the mechanistic basis of ecological interaction between NPs and resourceful bacteria. These results also emphasize to develop strategies for the safe disposal of NPs.
PubMed: 32309695
DOI: 10.1021/acsomega.9b04084 -
Environmental Technology Sep 2023The aftermath of mining weathered crust elution-deposited rare earth ore produces a large amount of residual ammonium leaching solution, which causes ammonia and...
The aftermath of mining weathered crust elution-deposited rare earth ore produces a large amount of residual ammonium leaching solution, which causes ammonia and nitrogen pollution to the mine site. Recently, denitrification by heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria has attracted much attention. However, limited studies exist regarding the denitrification process of HN-AD bacteria. In this study, we combined four strains of HN-AD bacteria, K3, K17, A12, and A16, obtained from rare earth element leaching sites, to select the best microbial consortium for ammonia nitrogen removal. We designed an ammonia removal process applicable to HN-AD bacteria to directly remove ammonia nitrogen from acidic leaching solutions. The experimental results demonstrated that the most efficient microbial consortium for ammonia nitrogen removal to be K3 + K17 + A16, with a removal efficiency of 89.68% for 8 h. In this process, considering the influencing factors of the ammonia removal process, the larger the influent flow rate and influent ammonia nitrogen concentration, the greater the ammonia nitrogen accumulation and pH decrease in the reactor. In consecutive multi-batch experiments, the ammonia removal process was used to remove ammonia nitrogen, at concentrations of 100-600 mg/L, from the simulated leaching solution at pH 4-7, whereby the effluent ammonia nitrogen concentration was lower than 15 mg/L. The results demonstrate that the ammonia removal process is highly feasible and stable. These findings will provide new ideas for the application of HN-AD bacteria and new methods for the removal of ammonia nitrogen from acidic leaching solutions.
Topics: Nitrification; Ammonia; Denitrification; Ammonium Compounds; Nitrogen; Heterotrophic Processes
PubMed: 35388746
DOI: 10.1080/09593330.2022.2064235 -
Evidence-based Complementary and... 2022is a traditional Chinese medicine for treating gastrointestinal diseases by nourishing "Yin" and thickening the stomach lining. To study whether endophytes can...
is a traditional Chinese medicine for treating gastrointestinal diseases by nourishing "Yin" and thickening the stomach lining. To study whether endophytes can colonize the intestinal tract and regulate gut microbiota in mice, we used autoclave steam sterilizing and Co- radiation to eliminate endophytes from its juice. Then, high-throughput ITS1-ITS2 rDNA and 16S rRNA gene amplicons were sequenced to analyze the microbial community of endophytes and fecal samples of mice after administration of fresh juice. Sterilization of juice by autoclaving for 40 min (ASDO40) could more effectively eliminate the endophytes and decrease their interference on the gut microbiota. juice could increase beneficial gut microbiota and metabolites including short-chain fatty acids. endophytes , , s, , and could colonize the intestinal tract of mice and modulate gut microbiota after oral administration of the juice for 28 days. Thus, the regulatory effect of juice on gut microbiota was observed, which provides a basis for inferring that endophytes might colonize the intestinal tract and participate in regulating gut microbiota to treat diseases. Thus, this study further provides a new approach for the treatment of diseases by colonizing plant endophytes in the intestinal tract and regulating gut microbiota.
PubMed: 35990847
DOI: 10.1155/2022/2607506