摘要
由于底物和产物转运限制,重组大肠杆菌静息细胞转化苯丙氨酸合成苯乳酸的产量较低。针对上述问题,利用超声通透化处理静息细胞,提高静息细胞通透性,降低细胞屏障对催化作用的影响。使用超声破碎仪对静息细胞进行通透化处理,优化得到最佳超声处理条件:处理时间1 min、占空比80%、功率30%。对通透化细胞催化条件进行优化,得到最佳催化条件:pH7、35℃、缓冲液为磷酸盐缓冲液(phosphate buffered saline,PBS),最终苯乳酸的浓度从43.93 g/L提高到52.59 g/L,底物转化率从78.70%提高到94.59%。研究发现超声处理可以提高胞内苯丙氨酸、苯丙酮酸和苯乳酸的转运速率,从而提高整个反应的催化效率。该研究可为静息细胞催化过程细胞通透化处理提供理论指导。
Phenylalanine can be transformed to phenyllactic acid by resting recombinant Escherichia coli.However,substrate and product transport limitations restrict the yield of phenyllactic acid to far below industrially-relevant levels.Ultrasonic permeation was used to treat resting E.coli to improve the permeability and reduce the effect of the cell barrier on catalysis.Resting cells were permeated by an ultrasonic crusher.The optimized ultrasonic treatment conditions were 1 min treatment time 1 min,80%duty cycle,and 30%power.The optimized catalytic conditions of permeable cells were pH7,35℃,and phosphate buffered saline(PBS)as the buffer.The yield of phenyllactic acid increased from 43.93 g/L to 52.59 g/L,and the substrate conversion increased from 78.70%to 94.59%.Concentration changes of intracellular phenylalanine,phenylpyruvic acid,and phenyllactic acid during the catalytic process were studied.Ultrasonic treatment improved the transport rate of substrate and products,and thus improved the catalytic efficiency of the whole reaction.The findings provide theoretical guidance for the process of cell permeabilization during resting cell catalysis.
作者
侯颖
刘洋
王浩源
刘杨韬
孙宇婷
张荣飞
周中凯
张守庆
谭之磊
贾士儒
HOU Ying;LIU Yang;WANG Hao-yuan;LIU Yang-tao;SUN Yu-ting;ZHANG Rong-fei;ZHOU Zhong-kai;ZHANG Shou-qing;TAN Zhi-lei;JIA Shi-ru(College of Biotechnology,Tianjin University of Science and Technology,Tianjin 300457,China;Tianjin Tianlong Agricultural Science and Technology Co.,Ltd.,Tianjin 300457,China;College of Food Science and Engineering,Tianjin University of Science and Technology,Tianjin 300457,China;ZhongKe BlueOcean Testing(Tianjin)Technology Co.,Ltd.,Tianjin 300457,China)
出处
《食品研究与开发》
CAS
北大核心
2022年第16期61-68,共8页
Food Research and Development
基金
国家自然科学基金(31771952)
工业发酵微生物教育部重点实验室暨天津市工业微生物重点实验室资助课题(2020KF006)
天津科技大学省部共建食品营养与安全国家重点实验室开放课题资助项目(SKLFNS-KF-202113)
天津科技大学校级大学生创新创业训练计划资助项目(202110057134)。
关键词
超声处理
通透化
苯乳酸
静息细胞
细胞膜
ultrasonic treatment
permeabilization
phenyllactic acid
resting cell
cell membrane
作者简介
侯颖(1986—),女(汉),博士研究生,研究方向:生物防腐剂。;通信作者:贾士儒(1954—),男(汉),教授,博士,研究方向:生物反应工程。
