青岛啤酒酵母和高浓酵母原生质体融合选育高浓酿造菌株

Strain Improvement through Protoplast Fusion between Tsingdao Brewer's Yeast and High-Gravity Yeast

以青岛啤酒酵母和高浓酵母为供试菌株,通过原生质体融合得到融合子。对融合子利用铜抗性初筛,利用耐压和发酵性能为指标进行实验室和100 L发酵复筛,并对融合子进行鉴定及遗传稳定性实验。结果表明:通过原生质体融合选育出的高浓菌株与青岛啤酒酵母菌株相比,表现出酵母数峰值高、降糖和还原双乙酰快的优势,且代谢风味物质组成与青岛啤酒酵母接近;经过连续使用8代后,其总染色体DNA指纹图谱保持一致,证明该菌株的遗传稳定性高。

In this study, protoplast fusants between Tsingdao brewer’s yeast and high-gravity yeast were developed and preliminarily screened for their copper resistance. On the basis of this investigation, secondary screening was carried out on a laboratory scale or in a 100 L fermentor with respect to pressure tolerance and fermentation performance. The results showed that the selected fusant strain was superior to Tsingdao brewer’s yeast, as manifested by higher alcohol peaks as well as faster sugar consumption and diacetyl reduction. Moreover, both yeast strains presented similar f lavor compounds prof ile during metabolism. The total chromosomal DNA fi ngerprinting of the fusant strain after 8 successive passages remained consistent, suggesting high genetic stability.