蜂蜜接合酵母对营养物质利用及其高糖胁迫应激代谢特性分析

研究6 株蜂蜜接合酵母利用碳源、氮源和维生素的能力，发现蜂蜜接合酵母6-7431对营养物质的代谢能力强于其他菌株，具有较好应用潜力。进一步利用扫描电镜、高效液相色谱检测等方法对该菌株在高糖胁迫下的细胞形态、繁殖方式和应激代谢产物进行探究，结果发现在300～550 g/L的高糖环境中，菌株6-7431能正常出芽生殖，其代谢产生的乙醇、甘油、海藻糖、有机酸（苹果酸、α-酮戊二酸和柠檬酸）等物质含量都远高于100 g/L含糖环境；在550～700 g/L高糖环境中，菌株6-7431的繁殖方式由出芽生殖逐渐变为孢子生殖，代谢产生的乙醇含量低于100 g/L含糖环境，但苹果酸和α-酮戊二酸质量浓度仍有所增加；在750 g/L高糖环境中，菌株6-7431严重失水，形态干瘪，其产生的乙醇体积分数为0.6%，基本停止发酵活动。研究结果揭示了高糖环境对蜂蜜接合酵母细胞形态、繁殖方式以及应激代谢产物的影响，对分析酵母的高糖耐受机制具有重要的参考价值。

Nutrient Utilization of Zygosaccharomyces mellis and Its Metabolic Characteristics in Response to High-Glucose Stress

The abilities of six Zygosaccharomyces mellis strains to metabolize carbon sources, nitrogen sources and vitamins were investigated. It turned out that Z. mellis 6-7431 had stronger ability of utilizing nutrients than the other strains. Then the physiological response of Z. mellis 6-7431 to high-glucose stress was characterized. Its morphology and reproduction pattern under high-glucose stress were observed using scanning electron microscopy (SEM). The concentrations of metabolites such as glycerol, trehalose and malic acid were also determined. Results showed that Z. mellis 6-7431 exhibited a normal budding reproduction and the concentrations of these metabolites were elevated in the glucose concentration range of 300-500 g/L relative to a 100 g/L concentration. When glucose concentration increased from 550 to 700 g/L, Z. mellis 6-7431 started to form spores gradually, and the concentrations of these metabolites varied. At a high glucose concentration of 750 g/L, strain 6-7431 was dehydrated and its morphology became wizened. All the metabolic activities of this strain were inhibited, and the alcoholic concentration was only 0.6% in the fermented broth. These findings facilitated our understanding of the physiological response to high-glucose exposure and glucose-tolerant mechanism of Z. mellis 6-7431.