Multienzyme System Mixed Solid-state Fermenting Distiller’s Grain To Produce Protein Feed

Using the distiller’s grain of Maotai-flavor solid fermentation liquor as the stuff, we screen one strain of Saccharomyces cerevisiae and four strains of function of Bacillus to construct the best combination of multienzyme system Bacillus. Then it is necessary to adopt the secondary new technology, which is mixed culture solid fermentation, and make use of the distiller’s grain of Maotai-flavor solid fermentation liquor so as to produce protein feed. Targeting at the medium and the culture condition of different strains aim to the optimization. Meanwhile, the parameter optimization of the secondary new technology can be achieved by sequential experimental design. And what we need to do is to make use of optimum technological parameter to take verification test. The main research results are as follows:1. We use the distiller’s grain of Maotai-flavor solid fermentation liquor as material, by preliminary selection of spread plate and the growth property study, screening the best strain of Saccharomyces cerevisiae (J2). By preliminary selection of spread plate, secondary screening of enzyme productivity, growth inhibition, strains combination and orthogonal design, screen4strains of Function of Bacillus:Y5, Y17, Y22and Y49, in a proportion of3:3:4:1to construct the multienzyme system Bacillus.2.Using one-factor and Box-Behnken Test optimize the seed medium components and the culture condition of the multienzyme system Bacillus combination, Saccharomyces cerevisiae, Geotrichum candidum and Trichoderma koningii, which can help to get the optimum parameters on the basis of distiller’s grains leaching liquid:(1) the optimal medium of the multienzyme system Bacillus:1.21%of glucose,2.67%of peptone and1.55%of mineral salt solution; the optimal culture condition:pH was7.0, the temperature of37℃,15h of culture time.(2) the optimal medium of Saccharomyces cerevisiae:1.56%of glucose,1.88%of peptone and0.77%of mineral salt solution; the optimal culture condition:pH was6.0, the temperature of25℃,24h of culture time.(3) the optimal medium of Geotrichum candidum:1.33%of glucose,2.50%of peptone and0.71%of mineral salt solution; the optimal culture condition:pH was4.5, the temperature of28℃,27h of culture time.(4) the optimal medium of Trichoderma koningii:1.80%of glucose,1.93%of peptone and0.41%of mineral salt solution; the optimal culture condition:pH was5.5, the temperature of26℃,48h of culture time.3. According to the sequential experimental design, making a one-factor-at-a-time experimentation test, Plackett-Burman Test, factorial experiment, method of steepest ascent, factorial experiment, center combination experiment in turn, organically link with the screening of important factors, primary initialization, rapid optimization and higher optimization phase is to form a whole, which means a process parameters optimization of the distiller’s grain of Maotai-flavor solid fermentation liquor so as to produce protein feed. The best process parameter optimization:K2HPO40.01%, MgSO40.02%,(NH4)2SO40.75%,5.68%of the wheat bran, pH was6.0, water content65%,30%of the loading capacity, the temperature of32.8℃, ferment for6d, production strains are mixture Saccharomyces cerevisiae and Geotrichum candidum and Trichoderma koningii as the same proportion, the inoculation amount is9%.4.Factory manufacture verification test demonstrates that making use of the distiller’s grain to produce protein feed with the best technological parameter and with6batches repeated trial to get the crude protein content is29.31%on average. Compared with the original dry distiller’s grains’ crude protein content of22.89%, new technology of making use of the distiller’s grain of Maotai-flavor solid fermentation liquor to produce protein feed with new technology has increased by28.05%. And pure protein content also have increased from19.71%to27.04%.