金属硫蛋白基因MT1A在大肠杆菌中的自诱导表达条件优化及其抗镉性  

Optimization of Auto-induction Expression Conditions of Metallothionein Gene MT1A in Escherichia coli and Its Cadmium Tolerance

作　　者：王昭[1,2] 王席[2] 杨威 彭冬[2] 柳忠玉[1,2] 

机构地区：[1]长江大学/湿地生态与农业利用教育部工程研究中心,湖北荆州434025 [2]长江大学生命科学学院,湖北荆州434025

出　　处：《河南农业科学》2016年第5期66-70,共5页Journal of Henan Agricultural Sciences

基　　金：长江大学湿地生态与农业利用教育部工程研究中心开放基金项目(KF201511);长江大学大学生创新创业训练计划项目(104892013034)

摘　　要：为了提高金属硫蛋白基因MT1A的高效表达和对重金属的抗性,以菌体密度、可溶性目的蛋白表达量为评价指标,对工程菌自诱导的培养条件(诱导时间、诱导温度)和培养基组分(蛋白胨、酵母粉、甘油、葡萄糖、乳糖)进行优化,并对其抗镉(Cd)性进行分析。结果表明,最优自诱导培养基组分为2.0%蛋白胨、2.0%酵母粉、0.3%甘油、0.05%葡萄糖、0.3%乳糖;重组菌自诱导表达最优培养条件为37℃培养3 h,然后25℃继续培养13 h,此时菌体密度、可溶性蛋白表达量、可溶性蛋白相对产量均最高,分别比未优化ZYM-5052培养基提高77.7%、94.0%、244.8%。当Cd2+浓度为0.5 mmol/L时,高效表达金属硫蛋白的菌株具有明显的抗Cd活性。In order to increase the protein yield and heavy metal resistance of metallothionein gene MT1 A,auto-induction medium composition（ tryptone,yeast extract,glycerol,glucose and lactose） and culture conditions（ induction time and temperature） were optimized with bacterial density and expression level of soluble target protein as evaluation indexes,and the Cd tolerance was detected. The results showed that the optimal auto-induction medium composition were 2. 0% yeast extract,0. 3% glycerol,0. 05% glucose,0. 3% lactose. The optimum culture conditions were cultivating in 37 ℃ for 3 h firstly,then culturing in25 ℃ for 13 h. Under the optimal condition,the bacterial density,the expression level and relative yield of soluble protein increased by 77. 7%,94. 0%,244. 8%,respectively,compared to the unoptimized ZYM-5052 medium. Furthermore,the engineered bacteria had an obvious resistance to 0. 5 mmol / L Cd2 ＋.

关 键 词：金属硫蛋白 可溶性表达 自诱导 抗镉性 

分 类 号：X171.5[环境科学与工程—环境科学] Q78[生物学—分子生物学]