沙雷氏菌CM01来源硫氧还蛋白的抗铬(VI)能力研究

Analysis of the Chromium (VI) Resistance of the Thioredoxin of Serratia sp. CM01

摘要: 目的：通过克隆Serratia sp. M01中的硫氧还蛋白编码基因trxA、trxC，构建原核表达载体并转化至E. coli BL21(DE3)中，探究工程菌的抗铬(VI)能力。方法：以Serratia sp. CM01的DNA作模板，采用PCR扩增trxA、trxC基因，构建表达载体pET-28a(+)-trxA、pET-28a(+)-trxC并转化至E. coli BL21(DE3)表达以构建工程菌。以测定工程菌的Cr(VI)耐受、生长曲线，确定工程菌的抗Cr(VI)能力。结果：利用基因克隆技术，成功构建出trxA、trxC工程菌。测定两种工程菌的生长情况，发现在无Cr(VI)条件下，三种工程菌生长曲线没有差异(P > 0.05)。在Cr(VI)的胁迫下，两种工程菌在稳定期的菌量为：Serratia sp. CM01 > trxA ≈ trxC > Control (P < 0.05)；两种工程菌的Cr(VI)耐受能力为Serratia sp. CM01 > trxA > trxC > Control (P < 0.05)。结论：trxA、trxC基因编码的蛋白均具备的耐受Cr(VI)能力，工程菌trxA抗Cr(VI)能力强于trxC，工程菌具有治理实际环境中Cr(VI)污染的潜力。

Abstract: Objective: The engineered bacteria’s chromium (VI) resistance was investigated by cloning the thi-oredoxin-encoding genes trxA and trxC from Serratia sp. CM01, constructing a prokaryotic expres-sion vector and transforming it into E. coli BL21(DE3). Methods: The DNA of Serratia sp. CM01 was used as a template to amplify the trxA and trxC genes by PCR, and the expression vectors pET-28a(+)-trxA and pET-28a(+)-trxC were constructed and transformed into E. coli BL21(DE3) for expression to construct the engineering bacteria. The Cr(VI) resistance of the engineered bacteria was determined by measuring the Cr(VI) tolerance and growth curves of the engineered bacteria. Results: By using gene cloning technology, trxA and trxC engineering bacteria were successfully constructed. The growth of the two engineered bacteria showed no difference under Cr(VI)-free cir-cumstances (P > 0.05). In Cr(VI) presence, the viable bacterial cell mount during the stabilization phase was Serratia sp. CM01 > trxA ≈ trxC > Control (P < 0.05), and the tolerance rate of Cr(VI) was ranked Serratia sp. CM01 > trxA > trxC > Control (P < 0.05). Conclusion: Cr(VI)-tolerance of the pro-teins corresponding to the trxA and trxC genes. trxA has a stronger anti-Cr(VI) ability than trxC. It can potentially handle Cr(VI) pollution in the virtual environment.