铬还原酶ChrT工程菌的遗传稳定性研究

摘要

目的研究重组铬还原酶ChrT工程菌的遗传稳定性。方法将ChrT工程菌传至50代，每10代进行遗传稳定性相关检测。同时设置不加菌液的对照组作为空白对照组。结果各代ChrT工程菌的菌落生长形态、革兰染色、生化反应结果与原代菌株一致；各代ChrT工程菌质粒稳定，ChrT基因序列未见突变或丢失；经异丙基硫代-β-D-半乳糖苷（IPTG）诱导表达后，各代ChrT工程菌的目的蛋白表达水平与原代无明显差别；在含六价铬[Cr（Ⅵ）]50 mg/L的LB液体培养基中，与空白对照组比较，48 h后各代ChrT工程菌培养基中Cr（Ⅵ）的质量浓度明显减少，差异均有统计学意义（P<0.05）；各代ChrT工程菌间除Cr（Ⅵ）能力比较，差异无统计学意义（P>0.05）。结论 ChrT工程菌生物学特性稳定，可用于治理环境中Cr（Ⅵ）的污染。%Objective To study the genetic stability of recombinant chromium reductase (ChrT) engineered bacterium. Methods The ChrT engineered bacterium was subcultured for 50 passages and the genetic stability related detection was per-formed in every 10 passages. At the same time the blank control group without adding the bacterial solution was set. Results The colony growth pattern,Gram′s staining and biochemical reaction results of every passage of ChrT engineered bacterium were con-sistent with the primary bacterial strain;plasmids in each passage of ChrT engineered bacterium were stable and ChrT gene se-quences had no mutation or loss;after IPTG induction expression,the expression level of target protein in each passage of ChrT engineering bacterium had no significant difference from the primary passage;in the liquid medium containing hexavalent Cr (Ⅵ) 50 mg/L LB,the mass concentration of Cr(Ⅵ)after 48 h in the ChrT engineering bacterial medium in each passage was significantly decreased compared with the blank control group,the difference was statistically significant(P<0.05);except the Cr(Ⅵ) ability, the differences among different passages of ChrT engineering bacterium had no statistical significance (P>0.05). Conclusion The ChrT engineered bacterium shows stable biological characteristics and can be used to govern the environmental Cr (Ⅵ) contamination.