Chromate reduction by a chromate-resistant bacterium, Microbacterium sp.
Heavy-metal chromium [Cr(VI)] is a ubiquitous environmental pollutant. Comparing with chemical reduction, microbiological reduction is considered to be a friendly and cheaper way to decrease the damage caused by chromate. A bacterial strain, CR-07, which is resistant to and capable of reducing chromate was isolated from a mud sample of iron ore and identified as a Microbacterium sp. The bacterium had a high degree of tolerance to chromate, and could grow in LB medium containing 4.08 mM of K(2)Cr(2)O(7). It also had a degree of resistance to other heavy metals, e.g. Cd(2+), Pb(2+), Zn(2+), Cu(2+), Co(2+), Hg(2+) and Ag(+). The bacterium could remove 1.02 mM of Cr(VI) from LB medium within 36 h of incubation. Chromate removal was achieved in the supernatant from the bacterial cultures, and corresponded to chromate reduction. The activity of chromate reduction by the bacterium was not related to enzymes or reducing sugars, while fluorometric assay suggested that glutathione, a chromate-reducing substance which was produced by the bacterium, was one of the factors that contributed to the reduction of Cr(VI).
Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Xiaohongshan 44#, Wuhan city, 430071, Hubei province, People's Republic of China.
Zhaoming
Z
Liu
Yan
Y
Wu
Chengfeng
C
Lei
Pengming
P
Liu
Meiying
M
Gao
D000192:Actinomycetales / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000633:toxicity*; D002840:Chromates / Q000378:metabolism* / Q000633:toxicity*; D016000:Cluster Analysis; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004783:Environmental Microbiology; D004785:Environmental Pollutants / Q000378:metabolism / Q000633:toxicity; D005978:Glutathione / Q000378:metabolism; D019216:Metals, Heavy / Q000633:toxicity; D008826:Microbial Sensitivity Tests; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
D000900:Anti-Bacterial Agents; D002840:Chromates; D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D004785:Environmental Pollutants; D019216:Metals, Heavy; D012336:RNA, Ribosomal, 16S; D005978:Glutathione