Copper (II) binding of NAD(P)H- flavin oxidoreductase (NfoR) enhances its Cr (VI)-reducing ability.

ABSTRACT: Microbes can reduce hexavalent chromium Cr (VI) to the less toxic and soluble trivalent Cr (III). Copper stimulates microbial reduction of Cr (VI) by the Bacillus, Ochrobactrum, and Gluconobacter species; however, the mechanism remains unclear. In our study, the rate of Cr (VI) reduction by Staphylococcus aureus LZ-01 was increased by 210 % when supplemented with 60 μM Cu (II). A putative NAD(P)H-flavin oxidoreductase gene (nfoR) was upregulated under Cr (VI) stress. NfoR-knockout mutant displayed impaired reduction of Cr (VI) and Cu (II)-enhanced Cr (VI) reduction by nfoR isogenic mutant was attenuated in the presence of Cu (II). In vitro tests showed an increased V _max value of 25.22 μM min^-1 mg^-1 NfoR in the presence of Cu (II). Together, these results i

SUBMITTER: Han H 

PROVIDER: S-EPMC5684319 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature