Bacterial reduction of selenium (Se) oxyanions (Se[VI] and Se[IV]) to elemental Se (Se[0]) is one of the major biogeochemical processes removing Se from agricultural drainage water and depositing Se in the sediment. This study was conducted to characterize Se-reducing bacterial populations in Lost Hills evaporation pond sediment and to observe their response to Se(VI) and organic C amendments. Se(VI) was removed from the dissolved phase in the sediment slurries amended with organic C with a decrease in redox potential (Eh). Se(VI) concentrations decreased from 2137 to 79 microg L-1 after 9 days of incubation in a 5% soil slurry. Upon our screening process, 9 Se(VI)- and 14 Se(IV)-reducing bacteria were isolated from sediment slurries and identified by amplification and sequencing of 16S rDNA. Bacillus strains appeared to be dominant in the bacterial assemblages active in Se(VI) and Se(IV) reduction in the sediment. Halomonas pacifica and Staphylococcus warneri were also identified as Se(IV)-reducers. Indigenous bacteria have a significant role in the biogeochemical cycling of Se and may be stimulated by addition of a suitable organic source for Se reduction. The bacterial strains isolated from salt-affected and Se-contaminated Lost Hills evaporation pond sediment may have potential application in removing Se from high salt drainage water.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.biortech.2005.04.038 | DOI Listing |
mSphere
December 2024
Department of Microbiology, Cornell University, Ithaca, New York, USA.
Unlabelled: The bacterial genus includes species found in environmental habitats like soil and water, as well as taxa adapted to be host-associated or pathogenic. High genetic diversity may allow for this habitat flexibility, but the specific genes underlying switches between habitats are poorly understood. One lineage of has undergone a substantial habitat change by evolving from a presumed soil-dwelling ancestral state to thrive in floral nectar.
View Article and Find Full Text PDFAppl Environ Microbiol
December 2024
Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA.
Unlabelled: Advances in DNA metabarcoding have greatly expanded our knowledge of microbial communities in recent years. Pipelines and parameters have been tested extensively for bacterial metabarcoding using the 16S rRNA gene and best practices are largely established. For fungal metabarcoding using the internal transcribed spacer (ITS) gene, however, only a few studies have considered how such pipelines and parameters can affect community prediction.
View Article and Find Full Text PDFEnviron Sci Technol
December 2024
Yunnan Provincial Key Lab of Soil Carbon Sequestration and Pollution Control, Faculty of Environmental Science & Engineering, Kunming University of Science & Technology, Kunming 650500, Yunnan China.
Polycyclic aromatic hydrocarbons (PAHs) are widespread contaminants that can accumulate in microorganisms, posing significant ecological risks. While previous studies primarily focused on PAH concentrations, the impacts of PAH self-clustering have been largely overlooked, which will lead to inaccurate assessments of their ecological risks. This study evaluates the toxic effects of four prevalent PAH clusters on microbes with an emphasis on comparing the cluster sizes.
View Article and Find Full Text PDFFront Cell Dev Biol
December 2024
Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Changes to the composition of the microbiome in neoplasia, is termed oncobiosis, may affect tumor behavior through the changes to the secretion of bacterial metabolites. In this study we show, that ursodeoxycholic acid (UDCA), a bacterial metabolite, has cytostatic properties in pancreatic adenocarcinoma cell (PDAC) models. UDCA in concentrations corresponding to the human serum reference range suppressed PDAC cell proliferation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!