甘蔗糖蜜酒精高产酵母的发酵特性研究

采用20L三联装发酵罐进行甘蔗糖蜜高浓度酒精发酵研究高产酿酒酵母(Saccharomyces cerevisiae)MF1001菌株的甘蔗糖蜜酒精发酵特性。结果表明,锤度为20°Bx的糖蜜对菌株生长和发酵均没影响,发酵的适宜温度为30℃,pH值4.0的发酵效果明显优于pH值3.80,传代培养16代及不同的接种量对菌株的发酵没有影响。按目前甘蔗糖蜜酒精生产的发酵工艺,用锤度为20°Bx糖蜜培养基培养菌株,制备种子液,然后将种子液与锤度为55°Bx的糖蜜培养基1∶1混合进行发酵,发酵50h的醪液酒精含量达到了13.2%(V/V),60h达13.8%(V/V),72h达14.3%(V/V)。发酵结束时醪液可发酵残糖含量低至0.44%,发酵效率分别为理论值88.6%(50h)、94.3%(60h)和98.6%(72h)。该菌株有望用于甘蔗糖蜜酒精发酵生产,提高甘蔗糖蜜酒精发酵的醪液酒精含量。

Studies on Alcohol Fermentation Features of a High-yield Saccharomyces cerevisiae Using Sugarcane Molasses as Feedstock

The alcohol fermentation features of a high-alcohol-yield Saccharomyces cerevisiae strain MF001 was investigated using sugarcane molasses as feedstock.The results showed that 20°Bx sugarcane molasses did not defect the cell growth and fermentation of the strain,the optimum temperature for fermentation by strain MF001 was 30℃ and the alcohol fermentation at pH4.0 was better than that at pH3.8.Successive subcultures（16 times）and inoculation amount had a minor influence on the strain＇s alcohol fermentation.By using the industrial process of alcohol fermentation from sugarcane molasses,i.e.,the strain was grown in medium of 20°Bx sugarcane molasses first for preparing the seed culture,followed by mixing the seed culture with medium of 55°Bx sugarcane molasses at 1∶1 ratio to proceed fermentation,the alcohol concentration reached 13.2%（V/V）,13.8%（V/V）and 14.3%（V/V）after 50,60 and 72h of fermentation,respectively.The residual fermentable sugar was low to 0.44% at the end of fermentation（72h）.The conversion efficiency was 88.6%（50h）,94.3%（60h）and 98.6%（72h）of the theoretical alcohol yield.These results implied that it was potential for enhancing significantly the alcohol concentration of fermentation with sugarcane molasses as feedstock by using MF1001 in industry.