汽爆秸秆膜循环酶解耦合丙酮丁醇发酵

利用新型的汽爆玉米秸秆膜循环酶解耦合发酵系统进行了丙酮丁醇发酵的研究，并对使用该系统所导致的丙酮丁醇梭菌(Clostridium acetobutylicum AS1.132)代谢的变化进行了讨论. 在稀释率为0.075 h-1的条件下，丁醇的产量为0.14 g/g (纤维素+半纤维素)，最大丁醇产率达到0.31 g/(L×h)，溶剂组成为丁醇:丙酮:乙醇65.3:24.3:10.4(体积比)，纤维素和半纤维素的转化率分别为72%和80%，使用单位纤维素酶所产生的丁醇量为3.9 mg/IU，是分步水解批次发酵的1.5倍. 利用该系统使酶解和发酵分别在各自最适的条件下同时连续进行，减少了纤维素酶的用量，有效地解除了酶解产物对纤维素酶的抑制作用，并减轻了溶剂产物尤其是丁醇对微生物活性的影响，延长了发酵周期.

Fermentation of Acetone and Butanol Coupled with Enzymatic Hydrolysis of Steam Exploded Cornstalk Stover in a Membrane Reactor

Enzymatic hydrolysis of steam-exploded cornstalk stover in a membrane reactor coupled with fermentation of acetone and butanol by Clostridium acetobutylicum AS1.132 was investigated. A butanol yield of 0.14 g/g (cellulose+hemicellulose) and the maximum butanol productivity of 0.31 g/(L×h) were obtained with the dilution rate of 0.075 h-1. The butanol yield per unit enzymes was 0.0039 g/IU which was 1.5 times as much as that by batch fermentation and the cost of enzymes decreased greatly. The ratio of butanol, acetone and ethanol was 65.3:24.3:10.4. The conversion rates of cellulose and hemicellulose were 72% and 80%, respectively. The inhibition of enzymatic hydrolysate on cellulase which could be used circularly was lightened greatly. Enzymatic hydrolysate was fed into the fermentor continuously to keep the concentration of solvent low, as a result, the inhibition of solvent, especially butanol, on microbial activity was effectively eliminated, and the fermentation cycle became longer.