文献类型：期刊文献

英文题名：Fed-batch culture of Nocardia sp. for epoxysuccinate hydrolase production

作者：Long, Qiongying[1]; Huang, Lei[1]; Li, Zhimin[1]; Ye, Qin[1]

机构：[1] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China

年份：2008

卷号：43

期号：4

起止页码：438

外文期刊名：Process Biochemistry

收录：EI(收录号：20081211158031)

语种：英文

外文关键词：Cells - Concentration (process) - Fermentation - Glucose

摘要：Fed-batch cultures of Nocardia sp. were carried out in a 5-l fermentor for production of cis-epoxysuccinate hydrolase (EH). Since EH production was significantly repressed by glucose, the cultivation process was divided into a growth phase on glucose and a production phase induced by cis-epoxysuccinate (ES). The cells of Nocardia sp. were unable to utilize exogenous tartrate, so the intracellular tartrate produced from ES was the only carbon source in the production phase, and supply of enough ES was crucial. When ES was supplied at a constant rate of 0.3 g/(l h), the specific EH activity of the culture was only 75.1 U/g wet cell weight (WCW) due to limitation of ES. When the ES concentration in the culture was maintained at about 5 g/l by adding more ES based on material balance, the specific EH activity reached 182 U/g WCW. The EH activity measured with intact cells was influenced by the ES concentration in the culture due to the effect on cell permeability, the activity in this study was measured with ultrasound-disrupted cells. ? 2008 Elsevier Ltd. All rights reserved.