化学改性甘蔗渣对固定化细胞发酵产丁醇的影响

旨在研究化学改性的甘蔗渣作为固定化载体对丙酮丁醇梭菌Clostridium acetobutylicum XY16发酵制备生物丁醇的影响。首先利用不同浓度的聚乙烯亚胺(PEI)和1 g/L戊二醛(GA)对甘蔗渣表面进行化学改性,增强甘蔗渣对Clostridium acetobutylicum XY16的附载能力。经4 g/L聚乙烯亚胺和1 g/L戊二醛改性的甘蔗渣(添加量10 g/L)应用到固定化批次发酵中,发酵36 h后丁醇和总溶剂浓度最高,分别达到了12.24 g/L和21.67 g/L,同时溶剂的生产速率达到0.60 g/(L·h),生产速率比游离细胞和未改性甘蔗渣固定化细胞分批发酵分别提高了130.8%和66.7%。在此基础上对改性甘蔗渣固定化的细胞进行6次重复批次发酵,丁醇和总溶剂的产量稳定,溶剂生产速率逐渐提高至0.83 g/(L·h),同时转化率也提高至0.42 g/g。

Effects of chemically modified sugarcane bagasse on butanol production by immobilized Clostridium acetobutylicum XY16

Sugarcane bagasse modified by polyethylenimine (PEI) and glutaraldehyde (GA) was used as a carrier to immobilize Clostridium acetobutylicum XY16 in the process of butanol production. The effects of chemically modified sugarcane bagasse on batch and repeat-batch fermentations were investigated. Batch fermentation was conducted with an addition of 10 g/L modified sugarcane bagasse and 60 g/L glucose, resulting in a high solvent concentration of 21.67 g/L and productivity of 0.60 g/(L·h) with the treatment of 4 g/L PEI and 1 g/L GA. Compared to the fermentations by free cells and immobilized cells on unmodified sugarcane bagasse, the productivity increased 130.8% and 66.7%, respectively. The fibrous-bed bioreactor also maintained a stable butanol production during repeat-batch fermentations, achieving a maximum productivity of 0.83 g/(L·h) with a high yield of 0.42 g/g.