提高丙酮丁醇梭菌产溶剂稳定性及防止退化的研究

摘要

The addition of sodium acetate to medium could stabilize the solvent production during continuous subcultures. Meanwhile, a degenerated strain designated as DNU83 with an obvious reduced production of solvent was isolated from the broth without addition of sodium acetate. The butanol production of DNU83 drastically decreased to one-sixth of that of NU22. Supplement of weak-acid salt such as acetate, butyrate and phosphate into medium could restore the solvent production of the degenerated DNU83. When benzyl viologen was simultaneously added, the promoted effect on butanol production was obvious. The results indicated that Clostridium acetobutylicum DNU83 produced 18. 01 g · L-1 butanol with a butanol ratio of 83.43% as grew in corn medium containing 30 mg · L-1 benzyl viologen and 4 g · L-1 K2HPO4. The butanol production was 24.09% higher than that of Clostridium acetobutylicum NU22.%在丙酮丁醇梭菌连续传代过程中,添加乙酸钠可增强其稳定性,同时在未添加乙酸钠的发酵液中分离获得溶剂产量明显降低的退化菌株DNU83,其丁醇产量为2.33 g·L-1,仅为初始菌株的1/6.培养基中添加乙酸钠、丁酸钠或K2 HPO4等弱酸盐均可恢复退化菌株的产溶剂能力,如同时添加苄基紫精,可显著促进丁醇合成.7％玉米培养基中添加4 g·L -1 K2 HPO4和30 mg·L-1苄基紫精,丁醇产量可达18.01 g·L-1,总溶剂21.59 g·L-1,丁醇比为83.43％,丁醇产量较未退化菌株NU22提高24.09％.