细菌将有毒的六价铬还原为三价铬。

Bacterial reduction of toxic Cr (VI) into Cr (III).

作者信息

Faisal Muhammad, Hasnain Shahida

机构信息

Department of Botany, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan.

出版信息

Sheng Wu Gong Cheng Xue Bao. 2004 Sep;20(5):774-8.

PMID:15974008

Abstract

Two chromium-resistant bacterial strains CrT-1 and CrT-13, which can tolerate K2CrO4 up to 40 mg x mL(-1) on nutrient agar, 25 mg x mL(-1) K2 CrO4 in nutrient broth, and up to 10 mg x mL(-1) in acetate-minimal media, were used in this study. On the basis of 16S rRNA, strain CrT-1 was identified as Ochrobactrum intermedium and CrT-13 as Brevibacterium sp.. Uptake of chromate was greater in living cells than in heat-killed cells. Ochrobactrum intermedium CrT-1 reduced 73% and 41% of Cr(V) while Brevibacterium CrT-13 reduced 62% and 48% Cr(VI) at an initial chromate concentration of 750, and 1500 microg x mL(-1), after 96 hours with an inoculum size of 9.6 x 10(7) cells mL(-1). Different heavy metals at low concentrations did not affect the reduction potential of the strains significantly. Ochrobactrum intermedium CrT-1 reduced 84% and 65% while Brevibacterium CrT-13 reduced 60% and 44% of Cr(VI) at an initial Cr(VI) concentration of 250 and 500 microg x mL(-1), respectively, in an industrial effluent sample.

摘要

本研究使用了两株耐铬细菌菌株CrT-1和CrT-13，它们在营养琼脂上可耐受高达40 mg·mL⁻¹的K₂CrO₄，在营养肉汤中可耐受25 mg·mL⁻¹的K₂CrO₄，在乙酸盐基本培养基中可耐受高达10 mg·mL⁻¹的K₂CrO₄。基于16S rRNA，菌株CrT-1被鉴定为中间苍白杆菌，CrT-13被鉴定为短杆菌属。活细胞对铬酸盐的摄取量高于热灭活细胞。在接种量为9.6×10⁷个细胞·mL⁻¹、初始铬酸盐浓度为750和1500 μg·mL⁻¹的情况下，96小时后，中间苍白杆菌CrT-1还原了73%和41%的Cr(Ⅵ)，而短杆菌CrT-13还原了62%和48%的Cr(Ⅵ)。低浓度的不同重金属对菌株的还原能力没有显著影响。在工业废水样品中，当初始Cr(Ⅵ)浓度分别为250和500 μg·mL⁻¹时，中间苍白杆菌CrT-1还原了84%和65%的Cr(Ⅵ)，而短杆菌CrT-13还原了60%和44%的Cr(Ⅵ)。