【摘 要】
：
In this work, a glutaryl-7-aminocephalosporanic acid acylase (GLA) coding gene was cloned from Pseudomonas diminuta NK703 which was screened from oilfield.The concerted effects of the expression syste
【机 构】
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State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China Uni
【出 处】
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2015年上海市研究生学术论坛(生物化工)
论文部分内容阅读
In this work, a glutaryl-7-aminocephalosporanic acid acylase (GLA) coding gene was cloned from Pseudomonas diminuta NK703 which was screened from oilfield.The concerted effects of the expression system, inducing condition and culture medium on the expression of NK703 GLA in E.coli were firstly investigated.The best combination was the recombinant E.coli strain of pET-28a+GLA/BL21(DE3) with 2.0 % (w/v) lactose inducing in YT medium at 25℃.Then, by optimizing the components of culture medium, a synthetic medium with dextrin and a feeding medium with glycerol as the carbon sources were developed to further enhance the GLA yield and improve the GLA solubility.In the end, the NK703 GLA activity increased about 50-fold, reached 14470± 465 U/L, and the GLA productivity and the proportion of soluble GLA to the total soluble protein attained 206.0±9.033 U L-1h-1 and 60.13 %, respectively.Scaling up the GLA production in 3.7 L fermenter under the optimized conditions identified in shake flask, the GLA activity also reached 12406±521 U/L, which was the highest report at fermenter level.
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