摘要
嗜热厌氧杆菌X514(Thermoanaerobactersp.X514)是纤维素乙醇生产中最具潜力的菌株之一。对X514在3种培养基中的生长及代谢特征进行分析后发现,培养基1190比GS-Ⅱ和2473更适合运用于X514的代谢研究及乙醇发酵。其次,分别在1190培养基中添加不同浓度的酵母提取物和葡萄糖,对X514的生长及代谢作进一步研究。结果表明,在0.5-2 g/L范围内,酵母提取物浓度的增加有助于提高X514的生物量,乙醇等产物的产量及乙醇产率,说明酵母提取物对X514生长及乙醇发酵有促进作用;在2-10 g/L范围内,葡萄糖浓度的增加可提高乙醇等产物的产量而不会改变各产物的产率;糖消耗量并不随着初始底物浓度的增加而线性增长,而是在一定阶段趋于消耗最大值。反映了X514在底物充分的条件下,只有通过改进其他制约条件,才有可能提高底物的利用率及产物的产率。
Thermoanaerobacter sp. X514 is a promising strain to be applied in cellulosic ethanol production. After analyzing the growthand metabolic characteristics of X514 in three different media, 1190 medium is found to be more suitable than GS-II and 2473 media in respect of research on the metabolic characteristics and ethanol fermentation of X514. Furthermore, different concentrations of yeast extract and initial glucose are added into 1190 medium to study the growth and metabolism of it. The results show that increases of yeast extract concentration within the range of 0.5 g/L to 2 g/L lead to an improvement in biomass, glucose consumption, ethanol yield and also the ethanol conversion rate. Results of the investigation in 1190 culture media added with different quantities of initial glucose illustrate that increase of initial substrate concentration can increase the yield of ethanol and other products, but the conversion rate of products will not have a substantial change. The glucose consumption will not increase accompanied with substrate addition, but reach its maximum at some stage, which indicates that the only method for enhancing the substrate consumption and ethanol yield is to break up the restrict conditions when the substrate is sufficient.
出处
《生物技术通报》
CAS
CSCD
北大核心
2012年第9期131-136,共6页
Biotechnology Bulletin
基金
国家自然科学基金项目(30800202)
留学回国人员科研启动基金
国家自然科学基金
英国皇家学会双边交流合作项目(31011130157)
