Identification of key chromium resistance genes in Cellulomonas using transcriptomics

This is the authors' abstract. We don't add key points for this paper.

Cellulomonas fimi Clb-11 can reduce high toxic Cr(VI) to less toxic Cr(III), and transcriptomics was used to reveal the key Cr(VI) uptake and reduction genes of C. fimi Clb-11 in this study. The results showed that under 0.5 mM Cr(VI) stress, 654 genes were upregulated. Among the upregulated genes, phosphate transport protein encoding genes phoU and TC.PIT , and molybdate transport protein encoding genes modA , modB , and modC were involved in the cell uptake of Cr(VI). Cytochrome c subunits encoding genes qcrA and qcrC were involved in the intracellular reduction of Cr(VI), and cytochrome c oxidase subunits encoding genes coxB and coxC were involved in extracellular electron secretion. Additionally, several unreported genes were found to be upregulated in C. fimi Clb-11 under Cr(VI) stress. The upregulated manganese transport protein encoding gene mntH may also assist Cr(VI) uptake in C. fimi Clb-11. Proton pump subunit encoding genes atpA , atpB , atpE , atpF , and atpH , as well as sodium-hydrogen antiporter subunit encoding genes mnhA and mnhC were upregulated, it may be involved in the extracellular proton secretion to reduce Cr(VI). Iron complex transport system substrate-binding protein encoding gene ABC.FEV.S , vacuolar iron transporter encoding gene VIT , FMN reductase gene encoding gene ssuE , and quinone oxidoreductase encoding genes qor and qorB were upregulated to reduce Cr(VI) in the intracellular. Our study showed theoretical importance by revealing the Cr(VI) reduction mechanism using chrome-resistant microorganisms. • C. fimi Clb-11 can reduce Cr(VI) to Cr(III) in LB medium. • Cr(VI) uptake and reduction by C. fimi Clb-11 was analyzed using transcriptomics. • The key genes in C. fimi Clb-11 were identified in the reduction of Cr(VI). • This study revealed the mechanism of microbial Cr(VI) resistance at the key genes.