To investigate the distribution and abundance of spirochaetal communities within anaerobic digesters, pyrosequencing of the 16S rRNA gene was conducted. Phylogenetic analysis identified a cluster which included the majority of core spirochaetal operational taxonomic units (OTUs) and environmental clones but no pure-culture strains. Distribution of the core OTUs demonstrated an importance of local factors in shaping the structure of Spirochaetes. Spirochaetal to bacterial 16S rRNA gene copy numbers varied from 1.3% to 30.0% depending on digester samples. Environmental variables were found to influence the relative abundance of Spirochaetes. In a batch anaerobic digestion experiment testing the response to different substrates, acetate most stimulated the activity of Spirochaetes, suggesting possible acetate oxidation by syntrophic acetate oxidation process. Taken together, the results obtained in this study provides an insight into the ecology of Spirochaetes in anaerobic digesters and a basis for future studies examining ecological function of these bacteria.
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http://dx.doi.org/10.1016/j.biortech.2013.02.070 | DOI Listing |
Environ Microbiol
January 2025
Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Minneapolis, Minnesota, USA.
Shotgun and proximity-ligation metagenomic sequencing were used to generate thousands of metagenome assembled genomes (MAGs) from the untreated wastewater, activated sludge bioreactors, and anaerobic digesters from two full-scale municipal wastewater treatment facilities. Analysis of the antibiotic resistance genes (ARGs) in the pool of contigs from the shotgun metagenomic sequences revealed significantly different relative abundances and types of ARGs in the untreated wastewaster compared to the activated sludge bioreactors or the anaerobic digesters (p < 0.05).
View Article and Find Full Text PDFFEMS Microbiol Lett
January 2025
School of Civil and Environmental Engineering, UNSW Sydney, NSW 2052, Australia.
Aeration is a common pretreatment method to enhance biogas production via anaerobic digestion of waste organic feedstocks such as unused food. While impacts on downstream anaerobic digestion have been intensively investigated, the consequence of aeration on the microbial community in food waste has not been characterised. Food waste has a low pH resulting from the dominance of lactic acid bacteria within the Firmicutes phylum.
View Article and Find Full Text PDFEnviron Res
January 2025
Research & Development Institute in Shenzhen, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, China. Electronic address:
Adding additives exogenously is an effective strategy to enhance methanogenic activity and improve AD stability. Corn straw-based biochar@MIL-88A(Fe) (BM) was synthesized herewith and used as an exogenous additive to boost methane (CH) production. After adding BM at 250 mg/g WAS VS, the accumulative CH production and maximum CH yield increased by 1.
View Article and Find Full Text PDFEnviron Res
January 2025
Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Canada; School of Civil & Environmental Engineering, Queensland University of Technology, Brisbane, QLD, Australia.
Anaerobic digestion is known to be sensitive to operational changes, such as hydraulic loading shock, yet the impact on the microbiome, particularly the active RNA-based community, has not been fully understood. This study aimed to investigate the performance of anaerobic reactors and their microbial communities under short-term hydraulic loading shocks. Using synthetic wastewater, the reactor was subjected to 24-hour shocks at three-fold and seven-fold the baseline loading rate, followed by DNA and RNA analyses to assess the system's resiliency and microbial responses.
View Article and Find Full Text PDFJ Infect Chemother
January 2025
Department of Clinical Laboratory, Kanazawa Medical University Hospital, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa 920-0293, Japan; Department of Infectious Diseases, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa, 920-0293, Japan. Electronic address:
A 70-year-old woman with a 6-month history of poor hygiene presented with a right occipital mass, ulceration, and neck swelling. The right occipital region was infested with approximately 100 fly maggots, and the mass contained a foul-smelling abscess. Maggots were removed, and the mass was drained, irrigated, and dressed with padding.
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