Studies On Screening Of Solid-state Fermentation Strains, Fermentation Conditions Of Distiller’s Grains And Its Application

Distiller’s grains is the main by-product of the brewing industry,which contains many nutrients that are not fully utilized to create favorable conditions for its compre- hensive utilization.But due to the particularity of the liquor brewing process,the distiller’s grains is high acidity and nutrient imbalance, the development and utilize- tion of distiller’s grains was restricted. The microbial strains was isolationed from the accumulation of natural fermentation of distiller’s grains.The production technique of distiller’s grains probiotics and its application effect were preliminarily studied.The results are as follows:1、A Bacillus which named SD was isolated from the fermentation of natural accumulation. The morphological characteristics, physiological and biochemical identification and rDNA 16S sequence analysis and phylogenetic tree were constructed. The strain was identified Bacillus subtilis SD(Bacillus subtilis SD)2、Effects of the solid-state fermentation conditions such as carbon sources, nitrogen sources, inorganic salt, initial pH value, inoculation, seed age and fermentation time were studied by using single-factor with Bacillus subtilis SD as tested strains. And the fermentation conditions were optimized by using response surface experiment. The results showed that the optimal medium component were as follows:wheat bran 50%, soybean cake powder 7%, zeolite powder 43%, glucose 2.0%, KH2PO4 0.4%, MgSO4·-7H2O 0.2%, MnSO4·H2O 0.05%, the ratio of substance to water was 1:0.7; the optimal fermentation conditions were:the initial pH Value 7.28, inoculation 10.18%, seed age 23.85h, cultural temperature 35℃, cultural time 84h, rotation speed 220r/min. Under these conditions, the live germ of Bacillus subtilis reached 1.75×1010 cfu/g.3、Application effects of the distiller grains production of Bacillus subtilis probiotic were studied In fattening pigs breeding.The results showed that the average daily gain increased 9.31%, the feed conversion ratio decreased 9.73%, the rate of diarrhea decreased 72.99%, the cost decreased 14.25%.