文献类型：期刊文献

英文题名：Significant improvement of Serratia marcescens lipase fermentation, by optimizing medium, induction, and oxygen supply

作者：Long, Zhang-De[1,2]; Xu, Jian-He[1]; Pan, Jiang[1]

机构：[1] Laboratory of Biocatalysis and Bioprocessing, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China; [2] Rice Research Institute, Guangxi University, 100 East Daxue Road, Nanning 530004, China

年份：2007

卷号：142

期号：2

起止页码：148

外文期刊名：Applied Biochemistry and Biotechnology

收录：EI(收录号：20074210872093)

语种：英文

外文关键词：Ammonium compounds - Carbon - Dissolved oxygen - Fermentation - Fermenters - Nitrogen - Optimization

摘要：Production of an extracellular lipase from Serratia marcescens ECU1010, which is an industrially important biocatalyst for the stereospecific synthesis of Diltiazem precusor, was carefully optimized in both shake flasks and a fermenter, using Tween-80 as the enzyme inducer. Dextrin and beef extract combined with ammonium sulfate were indicated to be the best carbon and nitrogen sources, respectively. With the increase of Tween-80 from 0 to 10 g l-1, the lipase production was greatly enhanced from merely 250 U l-1 to a maximum of 3,340 U l-1, giving the highest lipase yield of ca 640 U g-1 dry cell mass (DCW), although the maximum biomass (6.0 g DCW l-1) was achieved at 15 g l-1 of Tween-80. When the medium loading in shake flasks was reduced from 20 to 10% (ν/ν), the lipase production was significantly enhanced. The increase in shaking speed also resulted in an improvement of the lipase production, although the cell growth was slightly repressed, suggesting that the increase of dissolved oxygen (DO) concentration contributed to the enhancements of lipase yield. When the lipase fermentation was carried out in a 5-l fermenter, the lipase production reached a new maximum of 11,060 U l-1 by simply raising the aeration rate from 0.5 to 1.0 vvm, while keeping the dissolved oxygen above 20% saturation via intermittent adjustment of the agitation speed (≥400 rpm), in the presence of a relatively low concentration (2 g l-1) of Tween-80 to prevent a potential foaming problem, which is easy to occur in the intensively aerated fermenter. ? Humana Press Inc. 2007.