酵母浸粉刺激以木薯为原料的丁醇生产的发酵相转型

Yeast Extract Stimulates the Phase-shift in Cassava Based Bio-butanol Production

在7L静态厌氧发酵罐下,使用"非粮"作物木薯替代玉米淀粉开展丁醇发酵。无论是传统发酵还是油醇萃取发酵,木薯粉丁醇发酵的性能均远不及以玉米淀粉为原料时的水平,主要体现在发酵产酸相向溶剂生产相的转型严重迟延或无法转型、发酵时间长、丁醇生产效率低。实验结果表明,当发酵相转型迟延出现后,添加2.5g/L的酵母浸粉,可以刺激丁酸/乙酸向丁醇/丙酮的转化、转型延迟时间缩短10～30h左右。在此条件下,传统和萃取发酵方式下的丁醇总产量分别达到12.95g/L和29.81g/L,丁醇生产效率与使用玉米淀粉为原料时基本持平。

Cassava is very attractive in bio-butanol production for its natures of cheap,high productivity,and no competition with the foods for arable land.Cassava was used as the raw material to produce bio-butanol in a 7L static/anaerobic fermentor.The results indicated that,performance of cassava-based bio-butanol production was much lower than that of corn-based production in both traditional and extractive fermentations.The major problems include severe delay or complete failure in phases shifting from acidogenic phase into solventogenic phase,long fermentation time and low butanol productivity.The experimental results showed that adding 2.5g/L yeast extract when phases-shifting delay appeared,could stimulate solvents conversion from organic acids and shorten the phase-shifting time for about 10-30 hours.Under this condition and with traditional and extractive fermentation mode,final butanol concentration reached 12.95g/L and 29.81g/L respectively,and butanol productivity almost approached the equivalent levels when using corn as fermentation source.