文献类型：期刊文献

英文题名：Production of Alcaligenes faecalis penicillin G acylase in Bacillus subtilis WB600 (pMA5) fed with partially hydrolyzed starch

作者：Zhang, Min; Shi, Minlong; Zhou, Zheng; Yang, Sheng; Yuan, Zhongyi; Ye, Qin

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Chinese Acad Sci, Shanghai Inst Biol Sci, Shanghai Inst Biochem & Cell Biol, Shanghai 200031, Peoples R China;[3]Chinese Acad Sci, Shanghai Inst Biol Sci, Inst Plant Physiol & Ecol, Shanghai 200031, Peoples R China

年份：2006

卷号：39

期号：4

起止页码：555

外文期刊名：ENZYME AND MICROBIAL TECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000238932500005)】；

语种：英文

外文关键词：penicillin G acylase; Bacillus subtilis; starch; pH-stat; fed-batch culture

摘要：In this study, a recombinant strain Bacillus subtilis WB600 (pMA5) was used to produce Alcaligenes faecalis penicillin G acylase (PGA). The PGA activity and overall PGA productivity were respectively 378 and 7.13 U/l in a batch culture using a complex medium containing 25 g/l of soluble starch. Fed-batch cultures indicated that glucose had a negative effect on the production of PGA. Starch is a good carbon source, but it could not be directly used as a feed due to high viscosity after heat sterilization. A feed was prepared by limited hydrolysis of starch with a small amount of alpha-amylase, which greatly improved the fluidity with little formation of glucose. The production of PGA increased to 546 U/l by feeding of the partially hydrolyzed starch. When a mixture containing the partially hydrolyzed starch and Tryptone was added by using a pH-stat strategy, the PGA activity reached 1960 U/l, over five-fold of that obtained in the batch culture, and the overall productivity reached 19.6 U/l h, which was more than two-fold of that in the batch culture. (c) 2006 Elsevier Inc. All rights reserved.