| Bacillus subtilis is one of the most important microorganisms in daqu of liquor brewing,and it plays an important role in the sesame flavor liquor production..Bacillus subtilis is a kind of advantage strain which has a variety of functions.During the process of the Bacillus subtilis growth,it can produces a variety of beneficial metabolic enzymes,such as commonly used amylase,cellulase and protease.The enzymes can break down starch,cellulose and protein in raw materials.The product after decomposing can be used as a precursor of fragrant substancesl,it provides sufficient conditions during the process of growth for liquor aroma.Bacillus subtilis produces tetramethyl pyrazine which is a health factor in liquor.So the Bacillus subtilis content directly influences the quality of liquor.After decomposition of the product can be used as a precursor of fragrant substances,produced in the process of growth for liquor aroma and flavoured provide sufficient conditions.Bacillus subtilis has produced tetramethy pyrazine,tetramethy pyrazine as a health factor in liquor.The Bacillus subtilis content directly influences the quality of liquor.So the Bacillus subtilis can be used in sesame flavor liquor production.(1)GC-MS were used in this study qualitative analysis,the metabolites of strains of Bacillus subtilis can produce acetion and 2,3,5,6-tetramethylpyrazine.The qualitative experiment proved that Bacillus subtilis can produce a variety of enzymes,including the protease,amylase,cellulose enzyme.During fermentation in the corresponding enzyme production medium,including the protease enzyme activity to a maximum of 69 u/mL,amylase enzyme activity to a maximum of 64 u/mL,cellulase enzyme to live up to 33 u/mL.(2)In this study,fermentation medium and culture conditions were optimized.Using the one-factor experim-ental design and orthogonal experiment,the optimum culture medium and culture condition were ascertained.Raw material hydrolysis experiment results showed that the optimal hydrolysis combination was bran 25 g/L,wheat germ 20 g/L,soybean meal hydrolyzed 30 g/L.Under the conditions of enzyme treatment,the reducing sugar and protein content in the hydrolysate was 15.3 g/L and 16.4 g/L.Adding medium amount of corn starch 10 mL/L,disodium hydrogen phosphate 2 g/L,magnesium sulfate 1 g/L to the culture,thebacteria volume reached 2.48 × 1010 cfu/m L.The best conditions was the initial pH7.0,liquid 50 mL / 500 mL,inoculation amount 3%(volume ratio),shaking table speed of 200 r/min,culture temperature of 37 ℃.Undering the condition of the optimal cultivation of Bacillus subtilis,the sampling to determine the amount of biomass in the fermentation process,the fermentation period for 24 h,bacteria volume reached 17.8 g/L.And the bacteria concentration reached 3.26× 1010cfu/mL.(3)In this study,the Bacillus subtilis additives was studied for drying:flour and starch proportion within the scope of the 1:2-1:3,granulating state was good,meeting production requirement.Orthogonal experiment showed that,each component content in the dry bacteria agent was dry weight 10%,flour 23.5%,starch 50%,trehalose 3%,glycerol 3.5%,calcium carbonate 1.5%,2.5% span-60 and water 6%.The bacteria survival rate lived up to 87.4%,the colony count reach 1.61 × 1011 cfu/g,shelf-life reached more than six months.(4)In this study,taked two groups of experiment using sesame flavor liquor production such as raw material,rice,sorghum,and wheat as raw material after adding water,cooking and sterilization,daqu powders were increased by yeast bran in group 1,daqu powders were increased by yeast bran and Bacillus subtilis bacteria agent in group 2.Taked semi-solid fermentation,the results of the two groups were significant differences.samples of total acid content was 0.14 g/L in group 1,while the total acidity was 0.16 g/L,total acid content increased by 14.3% in group 2.1 group esters content was 1.03 g/L,2 group esters content was 1.16 g/L,the experimental group esters content increased by 12.6%.1 set of the 2,3,5,6-tetramethylpyrazine accumulation achieved 5.4 mg/L,2 set of the 2,3,5,6-tetramethylpyrazine accumulation achieved 13.6 mg/L,final the 2,3,5,6-tetram-ethylpyrazine accumulation content increased by 154%.The results showed that: adding Bacillus subtilis bacteria agent into the semisolid medium,the bacteria soon refreshed.The composition of their mutual influenced the quality of the liquor. |
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