酱香型白酒酿造拜耳接合酵母生理代谢特征及其与地衣芽孢杆菌相互作用

Physiological characteristics of Zygosaccharomyces bailii and its interaction with Bacillus licheniformis in Chinese Maotai-flavor liquor making

摘要:

【目的】拜耳接合酵母(Zygosaccharomyces bailii)是酱香型白酒酿造过程优势菌株。通过研究拜耳接合酵母酿造相关生理代谢特征及其与酿造环境中其它功能菌株的相互作用，探索其在白酒酿造过程中的贡献。【方法】从酱香酒酿造中筛选一株性能优良的拜耳接合酵母，比较其与模式菌株(Z. bailii，ATCC 58445)的生理代谢特征。通过组合发酵研究其与产酱香特征风味细菌地衣芽孢杆菌的相互作用。【结果】从酱香型酒醅中筛选得到一株性状优良的拜耳接合酵母(Z. bailii 15)，可耐受pH 2.0和37 °C高温及8%酒精浓度(体积比)，较模式株更适应酿造环境，酒精产量(33.58 g/L)也远高于模式株(19.04 g/L)，且与酱香型白酒酿酒酵母MT1 (34.29 g/L)相当。该菌可产多种风味物质，与模式株相比，独特产生法呢醇、十二醇、2-壬醇、2-乙基己醇、癸酸、月桂酸、辛酸、辛酸乙酯、苯乙酮、4-叔丁基苯酚。共培养体系中，30 °C条件下地衣芽孢杆菌对拜耳接合酵母生长影响不大，而在37 °C地衣芽孢杆菌抑制拜耳接合酵母生长。此外，地衣芽孢杆菌对拜耳接合酵母乙醇转化率有促进作用，共培养体系风味物质种类及含量也都受到很大影响。【结论】拜耳接合酵母在酱香型白酒酿造体系中产酒精、产风味方面表现优异，对酱香型白酒生产具有重要贡献。

Abstract:

[Objective] Zygosaccharomyces bailii is the dominant strain in the brewing process of Maotai-flavor liquor. To explore the contributions Z. bailii made to the brewing procedure, its physiological characteristics and interaction with other functional strains in the brewing environments was studied. [Methods] One excellent phenotype Z. bailii strain was filtered from the fermented grains of Maotai-flavor liquor, and then comparing its physiological characteristic, metabolic function with ATCC 58445 and studying the combinated fermentation with Maotai-flavor characteristics bacteria Bacillus licheniformis. [Results] Z. bailii 15 with excellent phenotype from fermented grains was obtained, which could tolerate pH 2.0, 37 °C, 8% alcohol concentration (V/V) and more suitable for the brewing environment when comparing with ATCC 58445. Its ethanol production (33.58 g/L) was even to the Saccharomyces cerevisiae MT1 (34.29 g/L), which was far higher than the type strain (19.04 g/L). It can specificly produce 3,7,11-Trimethyl-2,6,10- Dodecatrien-1-ol, 1-Dodecanol, 2-Nonanol, 2-Ethylhexanol, Decanoic acid, Lauric acid, Octanoic acid, Ethyl octanoate, Acetophenone, 4-Tert-butylphenol. In the co-culture system, B. licheniformis inhibits the growth of Z. bailii at 37 °C, but has little effect on 30 °C. In addition, MT6 promotes the conversion of ethanol produced by Z. bailii 15, it can also affects the species and content of flavor greatly. [Conclusion] Z. bailii shows a significant performance in ethanol production and flavor production, which made it have a great contribution to the Maotai-flavor liquor production.