混菌发酵体系中异常汉逊酵母生长抑制机制研究

Mechanism of Early Growth Arrests of Hansenula anomala in Mixed Culture with Saccharomyces cerevisiae

为揭示异常汉逊酵母(Hansenula anomala)早期衰亡的特征及机制,建立酿酒酵母(Saccharomycescerevisiae)与异常汉逊酵母混合发酵体系,研究酿酒酵母产酸、有氧混菌发酵、无氧添加新鲜培养基发酵、混菌发酵上清液及活、死酿酒酵母细胞添加对异常汉逊酵母生长的影响。结果表明,酵母产酸对异常汉逊酵母有抑制作用;有氧混菌和无氧添加新鲜培养基混菌发酵处理中,异常汉逊酵母的活菌数均高于无氧混菌发酵;而混菌发酵上清液添加后异常汉逊酵母的活菌数低于其纯培养;高浓度活酿酒酵母细胞的加入导致异常汉逊酵母的早期死亡,而死酿酒酵母细胞对异常汉逊酵母无抑制作用。因此,异常汉逊酵母早期衰亡,一方面是由酿酒酵母产酸及营养竞争造成,另一方面酿酒酵母的代谢产物及高密度活酿酒酵母细胞也会有促进作用。上述结果有助于加深对非酿酒酵母在果酒发酵中早于酿酒酵母衰亡的理解。

In order to reveal the characteristics and mechanism of early death of Hansenula anomala,this paper established a mixed fermentation system for Saccharomyces cerevisiae and H. anomala;and studied the effects of acids produced by S. cerevisiae,aerobic fermentation,mixed-culture in fresh medium without oxygen,mixed-culture supernatant,viable or dead S. cerevisiae cells on the growth of H. anomala. The results showed that the growth of H.anomala was inhibited by acid produced by yeast. In the fermentation treatments of aerobic mixed bacteria and anaerobic add fresh medium,the viable counts of H. anomala were all higher than that of anaerobic mixture fermentation;while the viable count of H. anomala in mixed-culture supernatant was lower after adding fresh medium.The presence of viable S. cerevisiae cells at high concentrations could cause the early death of H. anomala,while the dead S. cerevisiae cells had no inhibition effect on H. anomala. Therefore,the early death of H. anomala was due either to the acids produced by S. cerevisiae and nutrition competition during wine fermentation,or to growth-inhibitory compounds produced by S. cerevisiae and viable S. cerevisiae cells at high concentration. These results were very helpful for thorough understanding of why H. anomala died before S. cerevisiae during wine fermentation.