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Toxics May 2023As a kind of ubiquitous emerging pollutant, microplastics (MPs) are persistent in the environment and have a large impact on the ecosystem. Fortunately, some...
As a kind of ubiquitous emerging pollutant, microplastics (MPs) are persistent in the environment and have a large impact on the ecosystem. Fortunately, some microorganisms in the natural environment can degrade these persistent MPs without creating secondary pollution. In this study, 11 different MPs were selected as carbon sources to screen the microorganisms for degradable MPs and explore the possible mechanism of degradation. After repeated domestication, a relatively stable microbial community was obtained after approximately 30 days later. At this time, the biomass of the medium ranged from 88 to 699 mg/L. The growth of bacteria with different MPs ranged from 0.030 to 0.090 optical density (OD) 600 of the first generation to 0.009-0.081 OD 600 of the third generation. The weight loss method was used to determine the biodegradation ratios of different MPs. The mass losses of polyhydroxybutyrate (PHB), polyethylene (PE), and polyhydroxyalkanoate (PHA) were relatively large, at 13.4%, 13.0%, and 12.7%, respectively; these figures for polyvinyl chloride (PVC) and polystyrene (PS) were relatively slight, 8.90% and 9.10%, respectively. The degradation half-life (t) of 11 kinds of MPs ranges from 67 to 116 days. Among the mixed strains, sp., sp., and sp. grew well. The possible degradation mechanism is that such microbial aggregates can adhere to the surface of MPs and form complex biofilms, secrete extracellular and intracellular enzymes, etc., break the hydrolyzable chemical bonds or ends of molecular chains by attacking the plastic molecular chains, and produce monomers, dimers, and other oligomers, leading to the reduction of the molecular weight of the plastic itself.
PubMed: 37235247
DOI: 10.3390/toxics11050432 -
Frontiers in Microbiology 2023The root rot disease causes a great economic loss, and the disease severity usually increases as ginseng ages. However, it is still unclear whether the disease severity...
The root rot disease causes a great economic loss, and the disease severity usually increases as ginseng ages. However, it is still unclear whether the disease severity is related to changes in microorganisms during the entire growing stage of American ginseng. The present study examined the microbial community in the rhizosphere and the chemical properties of the soil in 1-4-year-old ginseng plants grown in different seasons at two different sites. Additionally, the study investigated ginseng plants' root rot disease index (DI). The results showed that the DI of ginseng increased 2.2 times in one sampling site and 4.7 times in another during the 4 years. With respect to the microbial community, the bacterial diversity increased with the seasons in the first, third, and fourth years but remained steady in the second year. The seasonal changing of relative abundances of bacteria and fungi showed the same trend in the first, third, and fourth years but not in the second year. Linear models revealed that the relative abundances of and spp. were negatively correlated with DI, while the relative abundance of spp. were positively correlated with DI ( < 0.05). The Mantel test showed that soil chemical properties, including available nitrogen, phosphorus, potassium, calcium, magnesium, organic matter, and pH, were significantly correlated to microbial composition. The contents of available potassium and nitrogen were positively correlated with DI, while pH and organic matter were negatively correlated with DI. In summary, we can deduce that the second year is the key period for the shift of the American ginseng rhizosphere microbial community. Disease aggravation after the third year is related to the deterioration of the rhizosphere microecosystem.
PubMed: 36865777
DOI: 10.3389/fmicb.2023.1097742 -
Microorganisms Jan 2023It is claimed that one g of soil holds ten billion bacteria representing thousands of distinct species. These bacteria play key roles in the regulation of terrestrial...
It is claimed that one g of soil holds ten billion bacteria representing thousands of distinct species. These bacteria play key roles in the regulation of terrestrial carbon dynamics, nutrient cycles, and plant productivity. Despite the overwhelming diversity of bacteria, most bacterial species remain largely unknown. Here, we used an oligotrophic medium to isolate novel soil bacteria for positive interaction with soybean. Strictly 22 species of bacteria from the soybean rhizosphere were selected. These isolates encompass ten genera (, , , , , , , , , and ) and have potential as novel species. Furthermore, the novel bacterial species exhibited plant growth-promoting traits in vitro and enhanced soybean growth under drought stress in a greenhouse experiment. We also reported the draft genome sequences of sp. strain SOY2 and sp. strain SOY23. Along with our analysis of 169 publicly available genomes for the genera reported here, we demonstrated that these bacteria have a repertoire of genes encoding plant growth-promoting proteins and secondary metabolite biosynthetic gene clusters that directly affect plant growth. Taken together, our findings allow the identification novel soil bacteria, paving the way for their application in crop production.
PubMed: 36838264
DOI: 10.3390/microorganisms11020300 -
Journal of Clinical Microbiology Jan 2023A number of factors, including microbiome analyses and the increased utilization of whole-genome sequencing in the clinical microbiology laboratory, has contributed to... (Review)
Review
A number of factors, including microbiome analyses and the increased utilization of whole-genome sequencing in the clinical microbiology laboratory, has contributed to the explosion of novel prokaryotic species discovery, as well as bacterial taxonomy revision. This review attempts to summarize such changes relative to human clinical specimens that occurred in 2020 and 2021, per primary publication in the or acceptance on Validation Lists published by the . Of particular significance among valid and effectively published taxa within the past 2 years were novel spp., coagulase-positive staphylococci, spp., and members of family . Noteworthy taxonomic revisions include those within the and genera, family (including unifications of subspecies designations to species level taxa), spp., and former members of spp. and spp. Revisions within the Brucella genus have the potential to cause deleterious effects unless the relevance of such changes is properly communicated by microbiologists to stakeholders in clinical practice, infection prevention, and public health.
Topics: Humans; Staphylococcus; Bacillus
PubMed: 36533910
DOI: 10.1128/jcm.00282-22 -
Infection and Drug Resistance 2022() infection is of great concern as these gram-negative bacillus species are multidrug-resistant and usually isolated from the patients' respiratory tract suffering...
() infection is of great concern as these gram-negative bacillus species are multidrug-resistant and usually isolated from the patients' respiratory tract suffering from cystic fibrosis (CF). A few cases of infection have also been reported in non-CF patients due to its rare pathogenic nature with unclear and overlapping clinical, biochemical, and microbiological characteristics with other species. Here, we report an unusual case of a 46-year-old non-CF female, who presented with multiple pelvic fractures, acute traumatic brain injury, multiple rib fractures, and multiple burns (18% of the total body surface area, II°) by the collapse of a brick kiln, suffered from sepsis due to wound infection. Pandoraea species were isolated both from her blood and wound secretion. Antibiotic susceptibility testing indicated susceptibility to imipenem, tetracyclines, sulfamethoxazole, and ampicillin/sulbactam but resistance to meropenem, quinolones, aminoglycosides, and other beta-lactams. 16S ribosomal RNA (rRNA) PCR assays and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to confirm the bacteria as . After effective anti-infection of intravenous antibiotics (imipenem 1.0 Q8H with tigecycline 50 mg Q12H for 14 days), wound care, and other comprehensive treatment for two months, the patient improved and was discharged from the hospital eventually. After reviewing the literature, we observed that the susceptibility results of Pandoraea species were often multidrug-resistant and had a unique pattern of being resistant to meropenem but sensitive to imipenem. Biofilm formation, carbapenemase production, and unique gene procession differed from the environmental isolates could help explain its resistance. This case report highlights the potential virulence of as a pathogen in patients with no underlying disease. Although they are often multi-resistant, imipenem can be a preferred treatment for Pandoraea species in the earliest identification steps.
PubMed: 36483145
DOI: 10.2147/IDR.S388520 -
Scientific Reports Nov 2022Polychlorinated Biphenyls (PCBs) are persistence in the contaminated sites as a result of lacking PCBs-degrading microorganisms. Cultivation-independent technique called...
Polychlorinated Biphenyls (PCBs) are persistence in the contaminated sites as a result of lacking PCBs-degrading microorganisms. Cultivation-independent technique called single-strand-conformation polymorphism (SSCP) based on 16SrRNA genes was chosen to characterize the diversity of bacterial communities in PCBs polluted soil samples. The bacterial communities showed an increasing diversity from the genetic profiles using SSCP technique. 51 single products were identified from the profiles using PCR reamplification and cloning. DNA sequencing of the 51 products, it showed similarities to Acidobacteria, Actinobacteria, Betaproteobateria, Gammaproteobacteria and Alphaproteobacteria, the range of similarities were 92.3 to 100%. Pure 23 isolates were identified from PCBs contaminated sites. The identified isolates belonged to genus Bacillus, Brevibacillus, Burkholderia, Pandoraea, Pseudomonas, and Rhodococcus. The new strains have the capability to use PCBs as a source of sole carbon and harbor 2,3-dihydroxybiphenyl dioxygenase (DHBDO) which could be used as molecular marker for detection PCBs-degrading bacteria in the PCBs contaminated sites. This finding may enhance the PCBs bioremediation by monitoring and characterization of the PCBs degraders using DHBDO in PCBs contaminated sites.
Topics: Polychlorinated Biphenyls; Soil; Soil Microbiology; Soil Pollutants; Biodegradation, Environmental; Bacteria; Biotechnology; Dioxygenases
PubMed: 36357504
DOI: 10.1038/s41598-022-23886-3 -
Microbiology Resource Announcements Dec 2022sp. strain NE5, an arsenite-oxidizing bacterium, was isolated from the rhizosphere of an arsenic hyperaccumulator fern (Pteris vittate). Here, the genome sequence of...
sp. strain NE5, an arsenite-oxidizing bacterium, was isolated from the rhizosphere of an arsenic hyperaccumulator fern (Pteris vittate). Here, the genome sequence of sp. strain NE5 is announced.
PubMed: 36342323
DOI: 10.1128/mra.00609-22 -
Microorganisms Aug 2022Microorganisms in extreme volcanic environments play an important role in the development of plants on newly exposed substrates. In this work, we studied the structure...
Microorganisms in extreme volcanic environments play an important role in the development of plants on newly exposed substrates. In this work, we studied the structure and diversity of a bacterial community associated to and at El Chichón volcano. The genetic diversity of the strains was revealed by genomic fingerprints and by 16S rDNA gene sequencing. Furthermore, a metagenomic analysis of the rhizosphere samples was carried out for pioneer plants growing inside and outside the volcano. Multifunctional biochemical tests and plant inoculation assays were evaluated to determine their potential as plant growth-promoting bacteria (PGPB). Through metagenomic analysis, a total of 33 bacterial phyla were identified from and rhizosphere samples collected inside the volcano, and outside the volcano 23 bacterial phyla were identified. For both rhizosphere samples, proteobacteria was the most abundant phylum. With a cultivable approach, 174 bacterial strains were isolated from the rhizosphere and tissue of plants growing outside the volcanic complex. Isolates were classified within the genera and . The evaluated strains were able to produce indole compounds, solubilize phosphate, synthesize siderophores, showed ACC deaminase and nitrogenase activity, and they had a positive effect on the growth and development of . The wide diversity of bacteria associated to pioneer plants at El Chichón volcano with PGPB qualities represent an alternative for the recovery of eroded environments, and they can be used efficiently as biofertilizers for agricultural crops growing under adverse conditions.
PubMed: 36013987
DOI: 10.3390/microorganisms10081568 -
PloS One 2022In this study, we sequenced a bacteria isolate Pandoraea sp. 892iso isolated from a Phytophthora rubi strain which is an important plant pathogenic oomycete, identified...
In this study, we sequenced a bacteria isolate Pandoraea sp. 892iso isolated from a Phytophthora rubi strain which is an important plant pathogenic oomycete, identified through genome and combined the data with existing genomic data from other 28 the genus of Pandoraea species. Next, we conducted a comparative genomic analysis of the genome structure, evolutionary relationships, and pathogenic characteristics of Pandoraea species. Our results identified Pandoraea sp. 892iso as Pandoraea sputorum at both the genome and gene levels. At the genome level, we carried out phylogenetic analysis of single-copy, gene co-linearity, ANI (average nucleotide identity) and AAI (average amino acid identity) indices, rpoB similarity, MLSA phylogenetic analysis, and genome-to-genome distance calculator calculations to identify the relationship between Pandoraea sp. 892iso and P. sputorum. At the gene level, the quorum sensing genes ppnI and ppnR and the OXA-159 gene were assessed. It is speculated that Pandoraea sp. 892iso is the endosymbiont of the Oomycetes strain of Phytophthora rubi.
Topics: Burkholderiaceae; Phylogeny; Quorum Sensing; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 35930552
DOI: 10.1371/journal.pone.0272435 -
ACS Central Science Jul 2022Dynamics is an essential process to drive an enzyme to perform a function. When a protein sequence encodes for its three-dimensional structure and hence its function, it...
Dynamics is an essential process to drive an enzyme to perform a function. When a protein sequence encodes for its three-dimensional structure and hence its function, it essentially defines the intrinsic dynamics of the molecule. The static X-ray crystal structure was thought to shed little insight into the molecule's dynamics until the recently available tool "Ensemble refinement" (ER). Here, we report the structure-function-dynamics of PanPL, an alginate-specific, endolytic, allosteric polysaccharide lyase belonging to the PL-5 family from . The crystal structures determined in apo and tetra-ManA bound forms reveal that the PanPL maintains a closed state with an N-terminal loop lid (N-loop-lid) arched over the active site. The B-factor analyses and ER congruently reveal how pH influences the functionally relevant atomic fluctuations at the N-loop-lid. The ER unveils enhanced fluctuations at the N-loop-lid upon substrate binding. The normal-mode analysis finds that the functional states are confined. The 1 μs simulation study suggests the existence of a hidden open state. The longer N-loop-lid selects a mechanism to adopt a closed state and undergo fluctuations to facilitate the substrate binding. Here, our work demonstrates the distinct modes of dynamics; both intrinsic and substrate-induced conformational changes are vital for enzyme functioning and allostery.
PubMed: 35912344
DOI: 10.1021/acscentsci.2c00277