Screening And Flavor Of Actinomyces In Maotai Brewing

Maotai-flavor liquor brewing has a long history,unique technology,open fermentation to create a special and complex microbial systems, resulting in Maotai-flavor liquor wine with a unique style.Maotai-flavor liquor micro-ecosystem system is contained in the scientific understanding of Maotai-flavor liquor fermentation biology, one of the key issues.Actinomycetes as one of main microbes in Maotai-flavor liquor brewing, contribute to both liquor flavor characteristics and micro-ecological functions.The analysis of mechanism affecting the microecological research and the flavor between actinomycetes and Maotai-flavor-producing function bacteria is conducive to in-depth study of Maotai-flavor liquor fermentation mechanism to promote further development of Maotai-flavor liquor.This study starting mud-odor- actinomyces, explore the cultivating flavor impact mechanism of Streptomyces albus subsp.(A22) and Maotai-flavor-producing function Bacillus amyloliquefaciens(B6) for the purpose.This study start with screening and appraisal of mud-odor-producing actinomyces, brewing conditions of environmental stress tolerance,characteristics of metabolites and the effects on metabolism characteristic flavor of B6,Etc.The following results have been achieved:(1)This study screened 30 strains actinomycetes form the process of Maotai flavor liquor brewing.Through the flavor-oriented screening technology, one strains of off-odor substances producing actinomyces was isolated from them and identified as Streptomyces albus subsp.(A22).(2)Using the turbidimetric method for A22 strain’s brewing environment stress tolerance analysis, results showed that:the strain of A22 resistant to high temperature45 ℃, 4% vol ethanol, pH4.0; its brewing better environmental adaptability.(3)Qualitative and quantitative analysis of B6,A22, A22 in solid state fermentation metabolic characteristic flavor compounds by HS-SPME and GC-MS,and found: The strain of A22 producing geosmin is the main source of mud-odor;Functional bacterium B6 producing pyrazines are an important source of Maotai flavor.The high temperature of 55 ℃ is favorable to increasing pyrazine’samount and types;The strain of B6 had inhibition of A22 producing Geosmin in mixed culture and normal conditions had benefit to reduce the off flavor of liquor brewing.In mixed culture, A22 inhibited B6’s pyrazine flavor amount, from the perspective of flavor there is a apparent adjustment between the strain of B6 and A22.(4)Analysis of the use of microecological relationship, counting method of microorganisms on A22 and B6,the results showed that there is a apparent adjustment between the strain of B6 and A22.