title: Optimum autoregulator addition strategy for maximum virginiamycin production in batch culture of Streptomyces virginiae.
abstract: Virginiae butanolides (VBs) are autoregulators of Streptomyces virginiae, which induce virginiamycin biosynthesis. Generally, autoregulators are synthesized by the microorganism itself during culture. Addition of chemically synthesized virginiae butanolide-C (VB-C), which is one of the VBs, can also control the induction time and the amount of virginiamycin production. The optimum concentration and shot-feeding time of VB-C for the maximum production of virginiamycins M and S were investigated in flasks and jar-fermentor batch cultures. VB-C addition later than 8 h from the start of culture induced not only virginiamycin M and S synthesis but also VB synthesis. Virginiamycin M and S production increased with the decrease of total VBs (produced VBs and added VB-C) concentration. That is, although VBs are needed to induce virginiamycin M and S synthesis, the amount of VB-C added should be such that as small an amount as possible of VBs is synthesized to achieve the maximum production of virginiamycins M and S. However, the VB-C addition earlier than 8 h from the start of culture showed no clear relationship between the amounts of VBs and virginiamycins M and S produced. In conclusion, the maximum production of virginiamycins M and S was attained by the shot addition of 5 mug/L VB-C at 8 h from the start of culture. The maximum value was about twofold that without VB-C addition. The optimum addition strategy of VB-C was confirmed by the jar-fermentor experiments. (c) 1995 John Wiley & Sons, Inc.
authors.affiliation: Department of Biotechnology, Faculty of Engineering, Osaka University, Suita Osaka 565, Japan.
authors.forename: Y K
authors.initials: YK
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
authors.forename: S
authors.initials: S
authors.lastname: Shioya
authors.forename: K
authors.initials: K
authors.lastname: Suga
authors.forename: T
authors.initials: T
authors.lastname: Nihira
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada