AUTHOR=Wang Dan , Wang Yicheng , Lv Xinyue , Cai Xunchao , Iqbal Waheed , Yang Bo , Zhou Dan , Rensing Christopher , Mao Yanping 

TITLE=Isolation of Anaerobic Bromate-Reducing Bacteria Using Different Carbon Sources and Transcriptomic Insights From Klebsiella variicola Glu3

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.851844

DOI=10.3389/fmicb.2022.851844

ISSN=1664-302X

ABSTRACT=<p>Bromate, a possible human carcinogen, can be reduced to innocuous bromide by microorganisms. To characterize bromate reducers, microbes were enriched anaerobically from activated sludge by using bromate as the sole electron acceptor and different carbon sources as the electron donor. Bacteria that showed significant bromate-reducing activity but not coupled to cell growth were isolated. Two whole genomes of the isolates, namely, <italic>Raoultella electrica</italic> Lac1 and <italic>Klebsiella variicola</italic> Glu3, were reconstructed by Illumina and Nanopore sequencing. Transcriptomic analysis suggested that neither the respiratory nitrate reductase, the selenate reductase, nor the dimethylsulfoxide reductase was involved in the bromate reduction process, and strain <italic>K. variicola</italic> Glu3 reduced bromate <italic>via</italic> a yet undiscovered enzymatic mechanism. The results provide novel phylogenetic insights into bromate-reducing microorganisms and clues in putative genes encoding enzymes related to bromate reduction.</p>