摘要
研究了茶氨酸生物合成基因工程菌重组质粒pET32a-GGT的稳定性。结果表明,该基因工程菌在连续传代100代后,质粒的目的基因片断没有缺失,具有结构稳定性;但在无抗生素选择压力下,连续传代20代后开始出现质粒丢失的细胞,连续传代100代后18%的细胞含有正常质粒,因此,表现出一定的分裂不稳定性。该基因工程菌在优化培养基和优化条件下的整个发酵过程中,始终表现出良好的结构和分裂稳定性,γ-谷氨酰转肽酶的活性为4.64U/ml,催化合成茶氨酸的产量为35.18g/L。
The stability of the recombinant plasmid pET32a-GGT in the genetically engineered E. coli bacteria strain for the biosynthesis of theanine was in investigated this ardcle. Result showed that the recombinant plasmid didn＇t appear obvious gene deletion, showed structural stability after 100 generations. However, the plasmid is showed segregational instability, the plasmid-free cells appeared after 20 generations, and 18% cells was plasmid-harboring cells after 100 generation under no Amp selection pressure. It was structural and segregational stability under optimizing culture medium and condition during the fermentation process, with activity of γ-GGT 4.64 U/ml and yield of theanine 35.18 g/L.
出处
《茶叶科学》
CAS
CSCD
北大核心
2008年第2期147-151,共5页
Journal of Tea Science
基金
浙江省科技计划项目(2007C22074)
中央级公益性科研院所基本科研业务费专项(0032007219)
关键词
茶氨酸
γ-GGT(γ-谷氨酰转肽酶)
基因工程菌
质粒稳定性
theanine, γ-GGT （γ-Gltamyltranspeptidase）, genetically engineered E. coli bacteria strain, plasmid stability
