A salt tolerant Enterobacter cloacae mutant for bioaugmentation of petroleum- and salt-contaminated soil
A salt tolerant Enterobacter cloacae mutant for bioaugmentation of petroleum- and salt-contaminated soil
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DOI：
10.1016/j.bej.2009.12.014
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发表时间：
2010-04-15
影响因子：
3.9
通讯作者：
Liu, Zheng
中科院分区：
文献类型：
--
作者：
Hua, Xiufu;Wang, Jun;Liu, Zheng
利用大气压辉光放电(APGD)等离子体诱变获得耐盐阴沟肠杆菌变异株(MU-1)。该变异体在泥浆培养中表现出规律性的生长行为，当以原油为唯一碳源(原油/土壤=1.5%)时，细胞密度分别达到5.72×10(8)和6.44×10(8)个菌落形成单位(CFU/mL)。在7.5%的氯化钠存在下，突变株MU-1对总石油烃(TPH)的降解率为7.94%，而野生型菌株的降解率为3.17%。在含盐条件下，MU-1的细胞膜透性略有变化，但细胞膜内K+浓度(2 h内从234.24 ppm/g干重增加到1422.88 ppm/g干重)和膜外多糖水平(从1 350 mg/g干重增加到1 825 mg/g干重)均显著增加。细胞内K+的快速增加和胞外EPS的同时积累可能是维持盐培养过程中渗透平衡的原因之一，这可能有助于MU-1的微生物生长和TPH降解。(C)2010爱思唯尔B.V.保留所有权利。
A NaCl-tolerant Enterobacter cloacae variant (MU-1) was obtained by mutagenesis using atmospheric pressure glow discharge (APGD) plasmas. The variant exhibited regular growth behavior in slurry cultivation and reached a cell density of 5.72 x 10(8) and 6.44 x 10(8) colony-forming units (CFU/mL) in the presence and absence of 7.5% NaCl, respectively, when crude oil was used as the sole carbon source (crude oil/soil = 1.5%). The total petroleum hydrocarbon (TPH) degradation percentage was 7.94% with mutant MU-1 in the presence of 7.5% NaCl whereas that of the wild-type strain was 3.17%. When cultivated in saline medium, MU-1 showed a slight change in membrane permeability but significant increases in both the K+ concentration inside the cell membrane (from 234.24 to 1422.88 ppm/g dry cell weight in the first 2 h) and the exopolysaccharide (EPS) level outside the membrane (from 1350 to 1825 mg/g dry cell weight). The rapid increase in K+ inside the cell and the simultaneous accumulation of EPS outside the cell may be responsible for maintaining the osmotic balance during saline cultivation, and this could facilitate the microbial growth and TPH degradation of MU-1. (C) 2010 Elsevier B.V. All rights reserved.