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

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.

Key words:Maotai-flavor liquor, Zygosaccharomyces bailii, Tolerance, Flavor, Interaction