FOOD SCIENCE ›› 2013, Vol. 34 ›› Issue (9): 143-149.doi: 10.7506/spkx1002-6630-201309030

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Optimization of Fermentation Process for Recombinant Escherichia coli Expression of Phospholipase C

ZHAO Jin-xing,ZHANG Liang*,GU Zheng-hua,DING Zhong-yang,SHI Gui-yang   

  1. State Key Laboratory of Food Science and Technology, Key Laboratory of Industrial Biotechnology, Ministry of Education, National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China
  • Received:2013-04-02 Revised:2013-04-22 Online:2013-05-15 Published:2013-05-07
  • Contact: ZHANG Liang E-mail:13861707271@139.com

Abstract:

The culture condition of Escherichia coli BL21 (DE3)/pET28a-plcH expressing the phospholipase C gene from
Pseudomonas aeruginosa 41 was optimized. The expression vector was cultured in TB medium and important parameters
such as the type of bufffer and the type and concentration of nitrogen source were optimized. Furthermore, the inducive
influences of IPTG, lactose and glycine on phospholipase C production were comparatively discussed. The optimized
medium composition was determined as (g/L): trytone 12, yeast extrat 24, glycerol 5, and Tris-HCl (0.25 mol/L, pH 7.2—7.4).
After sterilization, 0.15 g/L kanamycin was supplemented. In conical flasks, strain E. coli BL21 (DE3)/pET28a-plcH was
incubated at 37 ℃ and 200 r/min for six hours, followed by addition of 5 g/L lactose, and then the culture was maintained
at 25 ℃ and 150 r/min for twenty more hours. Under the optimized conditions, the final activity of phospholipase C was
(1422.42±37.17) U/mL. In a 7 L fermentor, the total activity reached (11583.35±70.21) U/mL with an intracellular activity of
(10957.97±58.03) U/mL and an extracellular activity of (645.27±13.87) U/mL.

Key words: phospholipase C, recombinant E. coli, fermentation process, optimization

CLC Number: