代谢副产物对Klebsiella pneumoniae生长及合成1,3-丙二醇的影响

研究了Klebsiella pneumoniae在厌氧摇瓶中的生长代谢特性和基质消耗情况，发现主要副产物乙醇是抑制菌体持续生长及1,3-丙二醇合成的主要因素，外源添加实验表明，8 g/L乙醇可使K. pneumoniae比生长速率、1,3-丙二醇比合成速率、最大菌体浓度及1,3-丙二醇终浓度分别下降21.6%, 22.1%, 59.6%及33.5%；指数生长期加入乙醇对菌体生长代谢的抑制作用更加明显. 其他代谢副产物乙酸、乳酸、2,3-丁二醇对K. pneumoniae生长代谢也有不同程度影响，乙酸浓度仅2 g/L即可对菌体生长产生抑制，乙酸浓度达到5 g/

Effect of By-products on Cell Growth and Biosynthesis of 1,3-Propanediol by Klebsiella pneumoniae

Biosynthesis of 1,3-propanediol attracted much attention recently.The cell growth and biosynthesis of 1,3-propanediol by Klebsiella pneumoniae tended to be ceased in the latter phase of anaerobic culture.The effect of environmental factors was studied in this work.It was indicated that the main by-product ethanol was the key inhibitor.Addition of 4 g/L ethanol in the culture medium would restrain the cell growth and 1,3-propanediol formation.By addition of 8 g/L ethanol,the maximum specific rates of cell growth and 1,3-propanediol biosynthesis,the maximum concentrations of biomass and 1,3-propanediol were decreased by 21.6%,22.1%,59.6% and 33.5% respectively.The inhibition potentials of other by-products on the anaerobic growth of K.pneumoniae were also detected.It was shown that the cell growth was inhibited obviously with 2 g/L acetic acid,yet it would not be affected even with 5 g/L 2,3-butanediol or 10 g/L lactic acid.