Isolation and characterization of Cr(VI) reducing Cellulomonas spp. from subsurface soils: implications for long-term chromate reduction.
Isolation and characterization of Cr(VI) reducing Cellulomonas spp. from subsurface soils: implications for long-term chromate reduction.
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DOI：
10.1016/j.biortech.2006.02.023
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发表时间：
2007-02
影响因子：
11.4
通讯作者：
S. Viamajala;W. A. Smith;R. Sani;W. Apel;J. N. Petersen;A. Neal;F. Roberto;D. Newby;B. Peyton
中科院分区：
文献类型：
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作者：
S. Viamajala;W. A. Smith;R. Sani;W. Apel;J. N. Petersen;A. Neal;F. Roberto;D. Newby;B. Peyton
美国能源部汉福德遗址沉积物中 Cr(VI) 污染和未污染的微生物富集在 Cr(VI) 存在下生长，并以乙酸盐、d-木糖或甘油作为碳源和能源，产生 Cr(VI) 还原聚生体。该联合体的 9 个分离株中有 8 个为革兰氏阳性，其中 4 个通过 16S rRNA 序列同源性和膜脂肪酸组成鉴定为属于纤维单胞菌属。进一步检查了 ES6 和 WS01 两种菌株在生长和非生长条件下还原 Cr(VI) 的能力。在 d-木糖上发酵生长期间，ES6 和 WS01 在不到三天的时间里将含水 Cr(VI) 浓度从 0.04mM Cr(VI) 降低至检测限 (0.002mM Cr(VI)) 以下，并且即使在培养四个月后仍保留其降低 Cr(VI) 的能力。洗涤后的 ES6 和 WS01 细胞在非生长条件下（无论是否存在外源电子供体）也能降低 Cr(VI) 四个多月。 K 边 XANES 光谱证实了 Cr(VI) 还原为 Cr(III)。生长停止后且在没有外部电子供体的情况下还原 Cr(VI) 的能力表明，刺激这些类型的生物体可能会产生有效的长期原位被动反应屏障，以去除 Cr(VI)。我们的结果表明，本土纤维单胞菌属可减少 Cr(VI)。可能是原位生物修复 Cr(VI) 污染的沉积物和地下水的潜在方法。
Microbial enrichments from Cr(VI) contaminated and uncontaminated US Department of Energy Hanford Site sediments produced Cr(VI) reducing consortia when grown in the presence of Cr(VI) with acetate, d-xylose or glycerol as a carbon and energy source. Eight of the nine isolates from the consortia were Gram positive and four of these were identified by 16S rRNA sequence homology and membrane fatty acid composition as belonging to the genus Cellulomonas. Two strains, ES6 and WS01, were further examined for their ability to reduce Cr(VI) under growth and non-growth conditions. During fermentative growth on d-xylose, ES6 and WS01 decreased aqueous Cr(VI) concentrations from 0.04mM Cr(VI) to below the detection limit (0.002mM Cr(VI)) in less than three days and retained their ability to reduce Cr(VI) even after four months of incubation. Washed ES6 and WS01 cells also reduced Cr(VI) under non-growth conditions for over four months, both with and without the presence of an exogenous electron donor. K-edge XANES spectroscopy confirmed the reduction of Cr(VI) to Cr(III). The ability to reduce Cr(VI) after growth had stopped and in the absence of an external electron donor, suggests that stimulation of these types of organisms may lead to effective long-term, in situ passive reactive barriers for Cr(VI) removal. Our results indicate that Cr(VI) reduction by indigenous Cellulomonas spp. may be a potential method of in situ bioremediation of Cr(VI) contaminated sediment and groundwater.