High density cell culture of recombinant bacillus megaterium pCK108 producing cellulase = 섬유소 분해효소를 생산하는 유전자 재조합 미생물인 bacillus megaterium pCK108의 고농도 배양

Cited 0 time in webofscience Cited 0 time in scopus
  • Hit : 271
  • Download : 0
For the production of extracellular carboxymethylcellulase(CMCase), fed-batch culture was carried out using a Bacillus megaterium transformed with a plasmid, pCK 108 harboring CMCase gene. It was observed that specific cellulase productivity of the cells was decreased significantly when high cell density($> 50$ g/l) was achieved with continuous feeding of glucose or lactose as a carbon source. This phenomenon was more significant when glucose was used as a carbon source. As glucose feeding rate increased above 4g/hr, cell density was increased up to 77.1 g-DCW/l but yield of CMCase based on cell mass was lowed sharply. To find out the main reason, inhibitory metabolites accumulated in the culture broth were analyzed and identified using gas chromatography and HPLC. More than 10 kinds of organic acids were detected, including intermediates of TCA cycle, acetate, propionate, and isobutyrate etc. Among them propionic acid and isobutyric acid showed strong inhibitiory effect on both cell growth and CMCase production. Especially, isobutyric acid was found to inhibit CMCase production by 70\% even at 10mM concentration. By reducing the inhibitory metabolites accumulation under slow feeding of lactose as a carbon source, cell growth and CMCase production could increase up to 55 g/l and 15.5 U/ml which were increased by 10 fold and 7 fold, respectively, comparing to the result obtained in batch culture. Lactose as a carbon source was found superior to glucose for CMCase production
Advisors
Kim, Jung-Hoeresearcher김정회researcher
Description
한국과학기술원 : 생물공학과,
Publisher
한국과학기술원
Issue Date
1994
Identifier
69821/325007 / 000875267
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 생물공학과, 1994.8, [ vii, 104 p. ]

URI
http://hdl.handle.net/10203/27362
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=69821&flag=dissertation
Appears in Collection
BS-Theses_Ph.D.(박사논문)
Files in This Item
There are no files associated with this item.

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0