【摘要】 研究了高酵母菌接种量的抑菌特性及对蔗汁乙醇发酵过程的影响。混合杂菌与酵母以不同浓度配比接入蔗汁发酵培养基中发酵,当增加酵母接种量达到5×10~7个/mL时,醪液中乙醇浓度没有明显降低。利用鲜甘蔗汁直接发酵时,接种量为5×10~7个/mL,乙醇产量达10.54%(20℃,v/v),与使用经高温灭菌的甘蔗汁作培养基,酵母接种量为2×10~7个/mL时相当,但发酵速度明显快于后者。其发酵上清液中未检出抑菌成分,说明提高酵母的接种量可以有效抑菌,其原因可能是酵母的生长处于竞争优势,抑制了杂菌的生长代谢。该研究为蔗汁发酵生产燃料乙醇,降低染菌风险提供了有效的尝试。更多还原

【Abstract】 This paper mainly studied the bacteriostatic action of high yeast inoculation and the effects on the fermentation of sugarcane juice to produce ethanol.Experiments were conducted using varies concentra- tions of the bacteria together with Saccharomyces cerevisiae.It was interesting to observe that increase the yeast inoculation rates of 5×10~7 cells/mL made no differences(P>0.2)in the final ethanol at any contami- nation levels,even when the sugarcane juice was infected with 1×10~8 bacteria/mL.Compared with the fer- mentation of sterilized sugarcane juice at standard recommendation inoculation of 2×10~7 cells/mL,no reduc- tion was observed in the final ethanol concentration in the fermentation of fresh sugarcane juice(unsterilized) at the inoculation rate of 5×10~7 cells/mL,as the ethanol concentration was 10.54%(20℃,v/v).Also the fermentation rate was improved.However,the yeast supernatant was evaluated by liquid culture of Lactobacillus plantrum,there is no inhibitory effect was found on the bacterial growth.This results demon- strated that a high yeast inoculation at the start of the sugarcane juice fermentation allows the yeast outgrow the contaminant bacteria and inhibits its growth and metabolism.This study put forward a novel approach to minimize the effects caused by bacterial contamination during industrial production of ethanol from sugarcane juice.更多还原