文献类型：期刊文献

英文题名：On-line ultrasound stimulates the secretion and production of gentamicin by Micromonospora echinospora

作者：Chu, J; Li, BL; Zhang, SL; Li, YR

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2000

卷号：35

期号：6

起止页码：569

外文期刊名：PROCESS BIOCHEMISTRY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000084040400005)】；

语种：英文

外文关键词：gentamicin fermentation; ultrasonic treatment; product secretion; Micromonospora echinospora

摘要：One of the main obstacles in the improvement of gentamicin (GM) productivity is considered to be the structure of the cell wall of Micromonospora spp, which impedes the release of GM from the cell into the broth. The results of the present study show that the release of intracellular GM into the broth increases from 38.3 to 75.8%, when off-line ultrasonic treatment is increased from 30 to 150 s. The fermentation time appropriate for on-line ultrasonic treatment was 84 h of fermentation, and this leads to a 70% increase in the secretion of chi. However, the increase of secretion slowed down at 108 h of fermentation, but still resulted in 42% more product in the broth. After 2 x 5 cycles on-line treatments of the broth (1500 ml), with a dosage of 7 min each cycle at 80 and 90 h, respectively, the secretion of GM was increased 3.8 times over the control, and the total GM titre was enhanced by 1.7 times. This suggests that the release of GM into the broth could alleviate the feedback regulation of GM biosynthesis. (C) 2000 Elsevier Science Ltd. All rights reserved.