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Scientific Reports Feb 2024Formate dehydrogenase (FDH) is critical for the conversion between formate and carbon dioxide. Despite its importance, the structural complexity of FDH and difficulties...
Formate dehydrogenase (FDH) is critical for the conversion between formate and carbon dioxide. Despite its importance, the structural complexity of FDH and difficulties in the production of the enzyme have made elucidating its unique physicochemical properties challenging. Here, we purified recombinant Methylobacterium extorquens AM1 FDH (MeFDH1) and used cryo-electron microscopy to determine its structure. We resolved a heterodimeric MeFDH1 structure at a resolution of 2.8 Å, showing a noncanonical active site and a well-embedded Fe-S redox chain relay. In particular, the tungsten bis-molybdopterin guanine dinucleotide active site showed an open configuration with a flexible C-terminal cap domain, suggesting structural and dynamic heterogeneity in the enzyme.
Topics: Cryoelectron Microscopy; Formate Dehydrogenases; Methylobacterium extorquens; Bacterial Proteins
PubMed: 38360844
DOI: 10.1038/s41598-024-54205-7 -
Cureus May 2024genus was initially described in 1993 as a "pink coccoid." It is a non-fermentative, aerobic, and gram-negative bacteria. This genus has been uncovered in diverse...
genus was initially described in 1993 as a "pink coccoid." It is a non-fermentative, aerobic, and gram-negative bacteria. This genus has been uncovered in diverse environmental niches, ranging from water and soil to air and plants. Despite its prevalence in the natural world, human infections stemming from species remain a rare occurrence. This organism is also known to be resistant to standard antibiotics. We present a case of an 85-year-old woman with (RG) bacteremia who is a resident at an assisted living facility. Healthcare providers should consider this bacterium in slow-developing gram-negative infections, potentially opting for broad-spectrum antibiotics as an initial treatment.
PubMed: 38899252
DOI: 10.7759/cureus.60667 -
Environmental Science & Technology Apr 2024Biological nitrogen fixation (BNF) has important ecological significance in mine tailing by contributing to the initial accumulation of nitrogen. In addition to...
Biological nitrogen fixation (BNF) has important ecological significance in mine tailing by contributing to the initial accumulation of nitrogen. In addition to chemolithotrophic and heterotrophic BNF, light may also fuel BNF in oligotrophic mine tailings. However, knowledge regarding the occurrence and ecological significance of this biogeochemical process in mine tailings remains ambiguous. The current study observed phototrophic BNF in enrichment cultures established from three primary successional stages (i.e., original tailings, biological crusts, and pioneer plants) of tailings. Notably, phototrophic BNF in tailings may be more active at vegetation stages (i.e., biological crusts and pioneering plants) than in bare tailings. DNA-stable isotope probing identified species as potential aerobic anoxygenic phototrophs responsible for phototrophic BNF. Furthermore, metagenomic binning as well as genome mining revealed that spp. contained essential genes involved in nitrogen fixation, anoxygenic photosynthesis, and carbon fixation, suggesting their genetic potential to mediate phototrophic BNF. A causal inference framework equipped with the structural causal model suggested that the enrichment of putative phototrophic diazotrophic may contribute to an elevated total nitrogen content during primary succession in these mine tailings. Collectively, our findings suggest that phototrophic diazotrophs may play important roles in nutrient accumulation and hold the potential to facilitate ecological succession in tailings.
Topics: Soil Microbiology; Nitrogen Fixation; Plants; Nitrogen; Soil
PubMed: 38551467
DOI: 10.1021/acs.est.3c09460 -
Journal of Advanced Veterinary and... Mar 2024The objectives of this study were to determine the richness, abundance, and diversity of bacteria in stray dogs () infested by ticks in Comarca Lagunera, northern...
OBJECTIVE
The objectives of this study were to determine the richness, abundance, and diversity of bacteria in stray dogs () infested by ticks in Comarca Lagunera, northern Mexico, and to establish their pathogenic and or/zoonotic potential.
MATERIALS AND METHODS
Blood samples from 12 dogs were collected, and their deoxyribonucleic acid was extracted. The V3-V4 region of the 16S ribosomal ribunocleic acid gene was amplified by polymerase chain reaction. Next-generation sequencing (NGS) was performed on a MiSeq Illumina platform, and the data were analyzed using quantitative insights into microbial ecology.
RESULTS
The operational taxonomic units resulted in 23 phyla, 54 classes, 89 orders, 189 families, 586 genera, and 620 bacterial species; among them, 64 species and/or bacterial genera with pathogenic or zoonotic potential were identified, some of which have been reported in the literature as relevant to public health ( spp spp spp spp spp spp spp and ).
CONCLUSION
This research offers relevant information on the prevalence of tick-borne diseases as well as other potential zoonotic diseases in the blood of stray dogs parasitized by ticks in northern Mexico. New molecular biology and massive NGS techniques may play an important role in the study and documentation of bacterial profiles from animals in close proximity to humans.
PubMed: 38680790
DOI: 10.5455/javar.2024.k757 -
Fish & Shellfish Immunology Aug 2023Aeromonas hydrophila frequently has harmful effects on aquatic organisms. The intestine is an important defense against stress. In this study, we investigated the...
Aeromonas hydrophila frequently has harmful effects on aquatic organisms. The intestine is an important defense against stress. In this study, we investigated the intestinal microbiota and transcriptomic and metabolomic responses of Cyprinus carpio subjected to A. hydrophila infection. The results showed that obvious variation in the intestinal microbiota was observed after infection, with increased levels of Firmicutes and Bacteroidetes and decreased levels of Proteobacteria. Several genera of putatively beneficial microbiota (Cetobacterium, Bacteroides, and Lactobacillus) were abundant, while Demequina, Roseomonas, Rhodobacter, Pseudoxanthomonas, and Cellvibrio were decreased; pathogenic bacteria of the genus Vibrio were increased after microbiota infection. The intestinal transcriptome revealed several immune-related differentially expressed genes associated with the cytokines and oxidative stress. The metabolomic analysis showed that microbiota infection disturbed the metabolic processes of the carp, particularly amino acid metabolism. This study provides insight into the underlying mechanisms associated with the intestinal microbiota, immunity, and metabolism of carp response to A. hydrophila infection; eleven stress-related metabolite markers were identified, including N-acetylglutamic acid, capsidiol, sedoheptulose 7-phosphate, prostaglandin B1, 8,9-DiHETrE, 12,13-DHOME, ADP, cellobiose, 1H-Indole-3-carboxaldehyde, sinapic acid and 5,7-dihydroxyflavone.
Topics: Animals; Gastrointestinal Microbiome; Transcriptome; Carps; Aeromonas hydrophila; Intestines; Gram-Negative Bacterial Infections; Fish Diseases
PubMed: 37271325
DOI: 10.1016/j.fsi.2023.108876 -
Antonie Van Leeuwenhoek Dec 2023Methylorubrum extorquens is an important model methylotroph and has enormous potential for the development of C1-based microbial cell factories. During strain...
Methylorubrum extorquens is an important model methylotroph and has enormous potential for the development of C1-based microbial cell factories. During strain construction, regulated promoters with a low background expression level are important genetic tools for expression of potentially toxic genes. Here we present an accordingly optimised promoter, which can be used for that purpose. During construction and testing of terpene production strains harbouring a recombinant mevalonate pathway, strong growth defects were observed which made strain development impossible. After isolation and characterisation of suppressor mutants, we discovered a variant of the cumate-inducible promoter P used in this approach. Deletion of 28 nucleotides resulted in an extremely low background expression level, but also reduced the maximal expression strength to about 30% of the original promoter. This tightly repressed promoter version is a powerful module for controlled expression of potentially toxic genes in M. extorquens.
Topics: Promoter Regions, Genetic; Methylobacterium extorquens; Methanol
PubMed: 37751033
DOI: 10.1007/s10482-023-01880-7 -
Microbiology Resource Announcements Nov 2023is a bacterium that is found in the natural microbiota of human skin. Here, we present sequence assemblies from isolated from the skin microflora of three healthy...
is a bacterium that is found in the natural microbiota of human skin. Here, we present sequence assemblies from isolated from the skin microflora of three healthy human volunteers that were used to treat atopic dermatitis patients.
PubMed: 37819097
DOI: 10.1128/MRA.00520-23 -
Microorganisms Mar 2024Recently, probiotics have been widely applied for the in situ remediation of aquatic water. Numerous studies have proved that probiotics can regulate water quality by...
Recently, probiotics have been widely applied for the in situ remediation of aquatic water. Numerous studies have proved that probiotics can regulate water quality by improving the microbial community. Nitrogen cycling, induced by microorganisms, is a crucial process for maintaining the balance of the aquatic ecosystem. Nevertheless, the underlying mechanisms by which probiotics enhance water quality in aquatic systems remain poorly understood. To explore the water quality indicators and their correlation with nitrogen cycling-related functional genes, metagenomic analysis of element cycling was performed to identify nitrogen cycling-related functional genes in aquatic water between the control group (C) and the groups supplemented with probiotics in feed (PF) or water (PW). The results showed that adding probiotics to the aquatic water could reduce the concentrations of ammonia nitrogen (NH-N), nitrite (NO-N), and total nitrogen (TN) in the water. Community structure analysis revealed that the relative abundance of Verrucomicrobiota was increased from 30 d to 120 d (2.61% to 6.35%) in the PW group, while the relative abundance of Cyanobacteria was decreased from 30 d to 120 d (5.66% to 1.77%). We constructed a nitrogen cycling pathway diagram for aquaculture ponds. The nitrogen cycle functional analysis showed that adding probiotics to the water could increase the relative abundance of the and (Nitrification pathways) and the and (Denitrification pathways). Correlation analysis revealed that NH-N was significantly negatively correlated with , , and , while NO-N was significantly negatively correlated with and . Our study demonstrated that adding probiotics to the water can promote nitrogen element conversion and migration, facilitate nitrogen cycling, benefit ecological environment protection, and remove nitrogen-containing compounds in aquaculture systems by altering the relative abundance of nitrogen cycling-related functional genes and microorganisms.
PubMed: 38543680
DOI: 10.3390/microorganisms12030627 -
PloS One 2023Nontuberculous mycobacteria (NTM) are ubiquitous environmental opportunistic pathogens that can cause chronic lung disease. Within the United States, Hawai'i has the...
Nontuberculous mycobacteria (NTM) are ubiquitous environmental opportunistic pathogens that can cause chronic lung disease. Within the United States, Hawai'i has the highest incidence of NTM lung disease, though the precise reasons are yet to be fully elucidated. One possibility is the high prevalence of NTM in the Hawai'i environment acting as a potential reservoir for opportunistic NTM infections. Through our previous initiatives to collect and characterize NTM in Hawai'i, community scientists of Hawai'i have collected thousands of environmental samples for sequencing. Here, these community scientists were invited for the first time into a high school lab in O'ahu for a genomic sequencing workshop, where participants sequenced four of the collected isolate genomic samples using the Oxford Nanopore Technologies MinION sequencer. Participants generated high quality long read data that when combined with short read Illumina data yielded complete bacterial genomic assemblies suitable for in-depth analysis. The gene annotation analysis identified a suite of genes that might help NTM thrive in the Hawai'i environment. Further, we found evidence of co-occurring methylobacteria, revealed from the sequencing data, suggesting that in some cases methylobacteria and NTM may coexist in the same niche, challenging previously accepted paradigms. The sequencing efforts presented here generated novel insights regarding the potential survival strategies and microbial interactions of NTM in the geographic hot spot of Hawai'i. We highlight the contributions of community scientists and present an activity that can be reimplemented as a workshop or classroom activity by other research groups to engage their local communities.
Topics: Humans; Hawaii; Nontuberculous Mycobacteria; Mycobacterium Infections, Nontuberculous; Chromosome Mapping; Data Accuracy; Methylobacterium
PubMed: 37703253
DOI: 10.1371/journal.pone.0291072 -
Folia Microbiologica Feb 2024The effectiveness of Methylobacterium symbioticum in maize and strawberry plants was measured under different doses of nitrogen fertilisation. The biostimulant effect of...
The effectiveness of Methylobacterium symbioticum in maize and strawberry plants was measured under different doses of nitrogen fertilisation. The biostimulant effect of the bacteria was observed in maize and strawberry plants treated with the biological inoculant under different doses of nitrogen fertiliser compared to untreated plants (control). It was found that bacteria allowed a 50 and 25% decrease in the amount of nitrogen applied in maize and strawberry crops, respectively, and the photosynthetic capacity increased compared with the control plant under all nutritional conditions. A decrease in nitrate reductase activity in inoculated maize plants indicated that the bacteria affects the metabolism of the plant. In addition, inoculated strawberry plants grown with a 25% reduction in nitrogen had a higher concentration of nitrogen in leaves than control plants under optimal nutritional conditions. Again, this indicates that Methylobacterium symbioticum provide an additional supply of nitrogen.
Topics: Zea mays; Fragaria; Methylobacterium; Nitrogen; Photosynthesis; Crops, Agricultural
PubMed: 37526803
DOI: 10.1007/s12223-023-01078-4