甘蔗糖蜜酒精高产酵母的发酵特性研究

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

关键词:  酵母菌株  发酵特性  酒精  糖蜜

Key words:  Saccharomyces cerevisiae strain  fermentation features  alcohol  molasses

摘要:

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。

Abstract:

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.