Complete genome sequence of the chromate-reducing bacterium Thermoanaerobacter thermohydrosulfuricus strain BSB-33

Abstract

Thermoanaerobacter thermohydrosulfuricus BSB-33 is a thermophilic gram positive obligate anaerobe isolated from a hot spring in West Bengal, India. Unlike other T. thermohydrosulfuricus strains, BSB-33 is able to anaerobically reduce Fe(III) and Cr(VI) optimally at 60 °C. BSB-33 is the first Cr(VI) reducing T. thermohydrosulfuricus genome sequenced and of particular interest for bioremediation of environmental chromium contaminations. Here we discuss features of T. thermohydrosulfuricus BSB-33 and the unique genetic elements that may account for the peculiar metal reducing properties of this organism. The T. thermohydrosulfuricus BSB-33 genome comprises 2597606 bp encoding 2581 protein genes, 12 rRNA, 193 pseudogenes and has a G + C content of 34.20 %. Putative chromate reductases were identified by comparative analyses with other Thermoanaerobacter and chromate-reducing bacteria.

Comparative Analysis of Carbon Monoxide Tolerance among Thermoanaerobacter Species

“…From recent genomic studies, it was confirmed that [Fe-Fe]-hydrogenases, responsible for hydrogen production, are present and well-conserved in all of the Thermoanaerobacter species. However, another class of hydrogenases, [Ni-Fe]-hydrogenases, is present only in T. thermohydrosulfuricus and T. wiegelii (Verbeke et al, 2013 ; Bhattacharya et al, 2015 ). [Fe-Fe] or iron-only hydrogenases are known to be more sensitive to CO than [Ni-Fe]-hydrogenases (Diender et al, 2015 ), which corroborate the results obtained regarding to the effect of CO on hydrogen production from glucose conversion by Thermoanaerobacter species.…”

“…Therefore, the high tolerance to CO and the potential of some microorganisms for CO utilization, make the members of Thermoanaerobacter genus important for the biotechnological use of syngas/industrial CO-rich gases. Thermophilic microorganisms including members of Thermoanaerobacter genus are interesting catalysts for production of biofuels (Carere et al, 2012 ; Verbeke et al, 2013 ; Hess et al, 2014 ; Bhattacharya et al, 2015 ; Sant'Anna et al, 2015 ). From this perspective the present study is important as CO is a way to steer the formation of fermentation products.…”

Genome Sequencing Revealed Chromium and Other Heavy Metal Resistance Genes in E. cloacae B2-Dha

“…In addition, B2-DHA possesses many other functional genes such as thioredoxin and thioredoxin reductase, dihydrolipoamide dehydrogenase, nitrite reductases, NADH: flavin oxidoreductase, quinones, cytochromes, flavoproteins and proteins with iron sulphur centers (Table 4). These genes are believed to be involved in metal oxidoreductase exhibiting Cr 6+ reduction as reported previously [58][59][60]. The proteins encoded by these genes initially catalyze one-electron shuttle followed by a two-electron transfer to Cr 6+ with the formation of intermediate(s) Cr 5+ and/or Cr 4+ before further reduction to Cr 3+ which is a critical process involved in detoxification of chromium inside the cells [21].…”

Microbial Chromate Reductases: Novel and Potent Mediators in Chromium Bioremediation-A Review

“…Genomic studies of ChrRs have been studied in bacteria as well as yeast species. Bhattacharya et al [53] have studied the complete genome sequence of chromate-reducing Thermoanaerobacter thermohydrosulfuricus BSB-33, a first report of Cr 6+ reducing strain. The sequenced genome of T.thermohydrosulfuricus BSB-33 comprised 2597606 bp and encoded 2581 protein genes, 12 rRNA and 193 pseudogenes.…”

“…Likewise, chromate reducing genes have also been cloned for amplification in suitable vectors by direct or other PCR techniques and studied for overexpression and annotations of their gene sequences and phylogenetic analysis. Bhattacharya et al [53] have first reported the complete genome sequence of ChrR in an anaerobic bacterium, Thermoanaerobacter thermohydrosulfuricus BSB-33 and have elucidated its genetic elements that mediate chromate reduction. The complete genome was annotated as part of the Oak Ridge National Laboratory genome annotation pipeline followed by manual curation using GenePRIMP gene predicting software.…”