Effects of cultivation conditions on the production of gamma-PGA with Bacillus subtilis ZJU-7.
Poly-gamma-glutamic acid (gamma-PGA) is a kind of water-soluble and biodegradable polymer made from D- and L-glutamic acid units, which are linked by amide bonds formed between alpha-amino and gamma-carboxylic acid groups. As a potential targeted biopolymer that can be refined from biomass directly, gamma-PGA has been increasingly applied to food, cosmetic, and pharmaceutical industries. In this work, a suitable nitrogen source was screened out for the high and cost-effective production of gamma-PGA in Bacillus subtilis ZJU-7. The effects of inoculation time and initial glucose concentration on the gamma-PGA production were investigated systematically in both shake flasks and a bench-top 15-l fermentor. Under the optimized culture conditions, a high gamma-PGA productivity (46.4 g/l) was obtained after 48 h cultivation at 37 degrees C. Finally, the large-scale fermentation of gamma-PGA production was successfully scaled up to a 100-l fermentor, with the highest gamma-PGA productivity for over 54.0 g/l.
Chen
Jie
J
Institute of Bioengineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, People's Republic of China.
Shi
Feng
F
Zhang
Bin
B
Zhu
Fan
F
Cao
Weifeng
W
Xu
Zhinan
Z
Xu
Guohua
G
Cen
Peilin
P
D001412:Bacillus subtilis / Q000737:chemistry / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism; D046508:Culture Techniques / Q000379:methods*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D007218:Industrial Microbiology / Q000379:methods*; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000378:metabolism
D003470:Culture Media; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D005947:Glucose