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Journal of Environmental Management Jul 2023P-Chloro-Meta-Xylenol (PCMX) is a widely used disinfectant. In the current pandemic scenario, its consumption has increased largely, and as a result, wastewater is...
P-Chloro-Meta-Xylenol (PCMX) is a widely used disinfectant. In the current pandemic scenario, its consumption has increased largely, and as a result, wastewater is loaded heavily with PCMX as a contaminant. Remediation of this ecologically toxic phenolic compound is therefore a burning issue. This study proposes an eco-friendly biosorption-based remediation technique to remove PCMX. A novel isolated phenol-resistant gram-negative bacterium, Pandoraea sp. strain BT102, is first encapsulated in biopolymeric calcium alginate beads. These beads are packed in a long adsorption tube and the contaminated water was passed through this packed tube resembling a plug flow reactor. This unique plug-flow set-up is capable of reducing PCMX concentration from 100 mg L to 2.85 μg L within 4 h using only 30 g of adsorbent, resulting in 99.99% removal efficiency. Adsorption isotherms and kinetics are studied using batch experimental data. A PCMX loading capacity of the encapsulated calcium alginate beads is found to be 961.7 mg g, and the Freundlich isotherm results suggested the phenomenon of cooperative adsorption. A good agreement of the pseudo-second-order kinetic model along with the intra-particle diffusion model suggests a multilayer diffusion-controlled adsorption process. Biosorption of PCMX by the bacterium-modified beads was confirmed by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Fourier-Transform Infrared spectroscopy (FT-IR) analyses. The application of multivariate model-based Response Surface Methodology (RSM) reveals flow rate to be the most important factor controlling the rate of bioremediation.
Topics: Alginates; Spectroscopy, Fourier Transform Infrared; Phenols; Bacteria; Adsorption; Kinetics; Hydrogen-Ion Concentration; Water Pollutants, Chemical
PubMed: 36989918
DOI: 10.1016/j.jenvman.2023.117764 -
Journal of Applied Microbiology Apr 2023Pandoraea pnomenusa MCB032 completely degrades chlorobenzene, whose metabolic pathway is encoded by cbs and clc gene clusters. The putative regulatory factors ClcR and...
AIMS
Pandoraea pnomenusa MCB032 completely degrades chlorobenzene, whose metabolic pathway is encoded by cbs and clc gene clusters. The putative regulatory factors ClcR and CbsR are predicted to regulate the cbs and clc gene clusters. This research aims to understand the function of ClcR and CbsR.
METHODS AND RESULTS
RT-PCR analyses demonstrated that the cbsFAaAbAcAdB operon that encodes catabolic pathways for the degradation of chlorobenzene to chlorocatechol is located on an operon. Moreover, the clcABCDE operon is involved in the 3-chlorocatechol pathway. Gene knockout and transcriptional analysis showed that the transcription of the cbsFAaAbAcAdB operon is positively regulated by CbsR, whereas the clcABCDE operon is activated by ClcR. Primer extension analysis was used to locate the transcription start sites of the cbsFAaAbAcAdB and cbsR operons. Electrophoretic mobility shift assay analyses showed that CbsR is bound to the sites in the promoter regions of cbsFAaAbAcAdB and cbsR operons.
CONCLUSION
The XylR/NtrC-type regulator CbsR positively regulates the transcription of the cbsFAaAbAcAdB operon encoding the upstream pathway of chlorobenzene catabolism, while the LysR-type regulator ClcR activates the clcABCDE operon encoding the downstream pathway.
Topics: Transcription Factors; Promoter Regions, Genetic; Base Sequence; Chlorobenzenes; Operon; Gene Expression Regulation, Bacterial; Bacterial Proteins
PubMed: 36965871
DOI: 10.1093/jambio/lxad064 -
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 -
International Journal of Systematic and... Feb 2023A Gram-stain-negative, strictly aerobic, motile, rod-shaped bacterium, FT117, was isolated from mangrove sediment collected in Shenzhen, Guangdong, PR China. Growth...
A Gram-stain-negative, strictly aerobic, motile, rod-shaped bacterium, FT117, was isolated from mangrove sediment collected in Shenzhen, Guangdong, PR China. Growth occurred at 20-45 °C (optimum, 40 °C), pH 6-10 (optimum, 8) and in the presence of 0-5 % NaCl (optimum, 0 %). The results of 16S rRNA gene sequence analysis indicated that the identity between FT117 and CC-CFT501 was the highest (98.7 %), followed by JCM 31785 (93.6 %), CCUG 34794 (93.6 %) and LMG 31012 (93.5 %). The main fatty acids (>10 %) were C (35.8 %), cyclo-C (18.5 %) and summed feature 3 (18.1 %). The polar lipids contained phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, two unidentified phospholipids, two unidentified aminophospholipids and one unidentified lipid. The sole respiratory quinone was ubiquinone-8 (Q-8). Its DNA G+C content was 70.6 % (data from the genome sequence) and the estimated genome size was 3.860 Mb. The average nucleotide identity values between the FT117 genome and the genomes of CC-CFT501, JCM 31785, CCUG 34794 and LMG 31012 were 85.4 %, 76.4 %, 73.0 % and 71.3 %, and the digital DNA-DNA hybridization values were 29.1 %, 21.0 %, 20.3 % and 19.1 %, respectively. The phylogenetic, phenotypic and chemotaxonomic differences between FT117 and its phylogenetic relatives indicate that FT117 should be regarded as representing a novel species within the genus , for which the name sp. nov. is proposed. The type strain is FT117 (=KCTC 92314 = MCCC 1K07396).
Topics: Fatty Acids; Phylogeny; RNA, Ribosomal, 16S; Bacterial Typing Techniques; DNA, Bacterial; Sequence Analysis, DNA; Base Composition; Phospholipids; China
PubMed: 36748486
DOI: 10.1099/ijsem.0.005673 -
Fish & Shellfish Immunology Feb 2023Cryptocaryon irritans is a parasitic ciliate of marine fish, causing serious mortality and economic loss of grouper. In this study, the orange-spotted grouper...
Effects of Cryptocaryon irritans infection on the histopathology, oxidative stress, immune response, and intestinal microbiota in the orange-spotted grouper Epinephelus coioides.
Cryptocaryon irritans is a parasitic ciliate of marine fish, causing serious mortality and economic loss of grouper. In this study, the orange-spotted grouper (Epinephelus coioides) were separately exposed to C. irritans infection for 72 h at a dose of 5000 or 10000 active theronts per fish, and we evaluated the changes in histopathology, oxidative stress, immune response, and intestinal microbiota composition. The results showed that C. irritans infection caused pathological alteration on the skin, gills, and liver of E. coioides. Oxidative stress responses occurred in the liver and gills, reflected in the corresponding antioxidant enzyme and gene indexes. The mRNA expression levels of inflammation-related genes (IL-1β, IL-6, and IL-8) and the mediators of apoptosis (casp3, casp9, and cytc) were increased in the liver and gills of the fish. C. irritans infection also affected the diversity and composition of intestinal microbiota. Specifically, the relative abundance of Firmicutes was increased, whereas that of Proteobacteria was decreased. Several potentially beneficial bacteria (Pandoraea, Clostridium sensu stricto 1, Christensenellaceae R-7 group, and Weissella) were decreased, whereas pathogenic bacteria (Streptococcus and Acinetobacter) were increased. In conclusion, this study reveals that C. irritans infection caused histopathology, immune disorders, and intestinal microbial community variation in E. coioides.
Topics: Animals; Bass; Ciliophora Infections; Gastrointestinal Microbiome; Phylogeny; Ciliophora; Hymenostomatida; Immunity; Oxidative Stress; Fish Diseases; Fish Proteins
PubMed: 36682479
DOI: 10.1016/j.fsi.2023.108562 -
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 -
British Journal of Haematology Feb 2023
Topics: Humans; Neutrophils; Burkholderiaceae; Bacteremia
PubMed: 36377533
DOI: 10.1111/bjh.18556 -
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