Monday, May 5, 2008
9-22

Screening and Optimization of Medium Composition for Poly(γ-glutamic acid) Production by Bacillus sp. RKY3 through Statistical Approaches

Jin-Nam Kim1, Jae-Hoon Jeong1, Young-Jung Wee2, and Hwa-Won Ryu2. (1) Higher Education Center for Bioregulator Research, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, South Korea, (2) School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, South Korea

Poly(γ-glutamic acid) (γ-PGA) is an unusual anionic, naturally occurring homo-polyamide that is made of D- and L-glutamic acid units connected by amide linkages between α-amino and γ-carboxylic acid groups. It is produced by microorganisms and chemical synthesis methods. In this study, to optimize the medium composition for γ-PGA production, Plackett-Burman factorial design and response surface methodology were studied.

We applied Plackett-Burman factorial design to screen and select factors affecting γ-PGA production by Bacillus sp. RKY3. Based on analysis of regression coefficients and t-value of 15 variables, we selected four components such as glycerol, glutamic acid, yeast extract, and K2HPO4 as significant factors increasing γ-PGA production. These four variables were chosen to obtain the optimum levels by response surface methodology. The maximum production of γ-PGA was predicted when 60 g/L of glutamic acid, 3 g/L of K2HPO4, 20 g/L of glycerol, and 2 g/L of yeast extract were used. This is obviously in close agreement with both the value of model prediction and results of previous conventional optimization of medium components.


See more of Poster Session Two
See more of General Submissions

See more of The 30th Symposium on Biotechnology for Fuels and Chemicals (May 4 -- 7, 2008)