| Autor: |
Xu-Sheng Chen, Shu Li, Li-Juan Liao, Xi-Dong Ren, Feng Li, Lei Tang, Jian-Hua Zhang, Zhong-Gui Mao |
| Zdroj: |
Bioprocess & Biosystems Engineering; Jun2011, Vol. 34 Issue 5, p561-567, 7p, 1 Chart, 5 Graphs |
| Abstrakt: |
The production of ε-poly- l-lysine (ε-PL) by Streptomyces sp. M-Z18 from glycerol was investigated in a 5-L jar-fermenter. Batch fermentations by Streptomyces sp. M-Z18 at various pH values ranging from 3.5 to 4.5 were studied. Based on the analysis of the time course of specific cell growth rate and specific ε-PL formation rate, a novel two-stage pH control strategy was developed to improve ε-PL production by shifting the culture pH from 3.5 to 3.8 after 36 h of cultivation. By applying the strategy, the maximal ε-PL concentration and productivity had a significant improvement and reached 9.13 g L and 4.76 g L day, respectively, compared with those in one-stage pH control process where the pH value is controlled at 3.5 (7.83 g L and 3.13 g L day). Fed-batch fermentation with two-stage pH control strategy was also applied to produce ε-PL; final ε-PL concentration of 30.11 g L was obtained, being 3.3-fold greater than that of batch fermentation. To our knowledge, it is the first report on production of ε-PL from glycerol in fermenter scale and achievement of high ε-PL production with two-stage pH control strategy. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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