利用以废弃毕赤酵母为氮源的丁酸发酵上清液和葡萄糖高效生产具有高丁醇/丙酮比特征的生物丁醇  

Efficient bio-butanol production featured with high butanol/acetone ratio using waste Pichia pastoris based butyrate fermentation supernatants and glucose as co-substrate

作　　者：宫立鹏 程文君 陈程[1] 陈雪寒 卫津宇 丁健[1] 史仲平[1] GONG Lipeng;CHENG Wenjun;CHEN Cheng;CHEN Xuehan;WEI Jinyu;DING Jian;SHI Zhongping(Key Laboratory of Industrial Biotechnology,Ministry of Education,School of Biotechnology,Jiangnan University,Wuxi,Jiangsu 214122,China)

机构地区：[1]江南大学生物工程学院,工业生物技术教育部重点实验室,江苏无锡214122

出　　处：《微生物学通报》2021年第5期1434-1449,共16页Microbiology China

基　　金：国家自然科学基金(21606106)。

摘　　要：【背景】生物丁醇是高效的液态燃料。丁醇发酵,也称丙酮-丁醇-乙醇(Acetone-Butanol-Ethanol,ABE)发酵,其发酵的产品是丁醇、丙酮和乙醇的混合物,主产物丁醇与主要副产物丙酮的质量比率(B/A比)约为2.0。【目的】丁酸是ABE发酵合成丁醇的重要前体物质,以丁酸/葡萄糖为双底物可以高效生产具有以高B/A比为特征的丁醇,提高ABE发酵产品的品质。【方法】7L厌氧发酵罐下,以玉米淀粉/废弃毕赤酵母处理液为原料得到的丁酸发酵上清液与葡萄糖溶液直接复配作为ABE发酵培养基,并按需要在发酵途中添加该上清液和浓缩葡萄糖溶液。【结果】与使用150 g/L玉米淀粉的传统ABE发酵相比,丁醇浓度保持在12.7-12.8 g/L的较高水平,B/A比从2.0大幅提高到4.4-5.0,丁醇对总碳源的得率从0.32-0.34提升至0.39-0.41 (摩尔基准),丁酸/葡萄糖质量消耗比高达37%-53%。【结论】ABE发酵性能的改善得益于丁酸发酵上清液中丁酸、寡糖和氨基酸等得到了有效利用,NADH利用效率大幅提高。该发酵策略节省了ABE发酵的原料和操作成本,大幅降低了丁酸发酵上清液中残存的寡糖浓度,还可根据市场供需和产品价格变化的状况实现发酵产品的多样性和生产操作的灵活性,具有良好的经济和环保意义。[Background] Bio-butanol is a powerful liquid fuel. The products of butanol fermentation(acetone-butanol-ethanol fermentation, ABE fermentation) are the mixture of butanol, acetone and ethanol, weight ratio of the primary product(butanol) over the major by-product(acetone)(B/A ratio) is about 2.0.[Objective] Butyric acid is an important precursor for butanol synthesis in ABE fermentation. Using butyric acid/glucose as co-substrate would efficiently produce butanol featured with high B/A ratio and improve the quality of ABE fermentation products. [Methods] In a 7-L anaerobic fermentor, the supernatant originated from butyrate fermentation(BFS) with corn starch/waste Pichia pastoris as the raw materials was directly mixed with glucose solution as the ABE fermentation medium, then BFS and concentrated glucose solution were fed during the fermentation as required. [Results] Compared with traditional ABE fermentation using 150 g/L corn, butanol concentration could be maintained at an equivalently high level of 12.7-12.8 g/L, B/A ratio largely increased from 2.0 to 4.4-5.0, butanol yield to total carbon source also increased from 0.32-0.34 to 0.39-0.41(mole base), butyrate/glucose consumption ratio reached high levels between 37% and 53%. The ABE fermentation benefited from the efficient utilization of butyrate, oligosaccharides, amino acids, etc. in the BFS and the enhanced NADH utilization efficiency. [Conclusion] The proposed fermentation strategy could save raw materials and operating costs of ABE fermentations, largely reduce the residual oligosaccharides concentrations in BFS, increase diversity and flexibility of the fermentation processes based on variations of marketing requirement and products prices, which have reasonably high economic and environmental effects.

关 键 词：丁醇发酵 丁酸/葡萄糖双底物 废弃毕赤酵母 寡糖 B/A 比 NADH 有效利用 

分 类 号：TQ923[轻工技术与工程—发酵工程]