Research Of Compound Strains Fermented Soybean Meal For Production Of Protein Fodder

High quality protein feeds such as fish meal, bone meal are serious in short supply as feed resources shortage is growing with the development of breeding industry and feed processing industries, so that the development of new protein feed is imminent. Soybean meal is the by-product of soybean oil. Fermented soybean meal which is processing by soybean meal as the main raw material has many advantages as a new type of feed. Fermentation improves protein content and degrades the antinutritional factors of soybean meal. It not only improves the nutritional value to reduce resource waste of soybean meal, but also creates a huge economic value and can better meet the needs of the breeding and animal husbandry. There is great significance to promote the efficient production instead of animal origin feed in feed industry.In this study, soybean meal are fermented by multiple microbe species as raw material with addition of a certain amount of inorganic salts and inorganic nitrogen source in order to obtain production of protein fodder. First three strains of hybrid modes of Aspergillus oryzae and Saccharomyces cerevisiae JM1, Aspergillus carbonarius and Saccharomyces cerevisiae JM1, Bacillus subtilis?Saccharomyces cerevisiae JM2 and Lactobacillus fermentum were screened out from various species combination modes. It is investigated that the influence of proportion of strains, microbial inoculation quantity, temperature, fermentation time, the ratio of material-water, bran addition quantity and molasses addition quantity for the total protein content that soybean meal fermented by mixed strains for through single factor experiment. On the basis, main nutrients and antinutritional factors of the fermentation products under the best conditions which optimized by the response surface optimization is tested and comparatively analyzed.The results of the study show as follows:(1)The plate confrontation test shows that Aspergillus oryzae and Saccharomyces cerevisiae JM1 are compatible with each other to be used to mix fermented soybean meal. Through the single factor tests and response surface optimization experiment it is concluded that the best fermentation condition: charge 25 g(91% of soybean meal, 7% of bran, 2% of molasses), addition of 0.375 g MgSO4, 0.25 g(NH4)2SO4, 0.25 g urea and 0.25 g K2HPO4 as inorganic nitrogen source and inorganic salts, the ratio of material to water is 1:1.1, microbial inoculation quantity is 13%, the fermentation temperature is 31.3 ?, fermentation time is 78.6 h. Under the best conditions, the total protein content reaches 56%, 13.96% higher than that of before fermentation; True protein content is 52.43%, 21.39% higher than that of before fermentation; The viable count achieves 1.38×109 cfu/g; Urease activity was reduced by 95.93%; Macromolecular protein is degraded into 14.4 KDa small molecule protein; Most of the antigen protein is degraded.(2)By using the single factor tests and response surface experiment to optimize the conditions of soybean meal which fermented by Aspergillus carbonarius and saccharomyces cerevisiae JM1, the best fermentation condition is given: charge 25 g(90% of soybean meal, 7% of bran, 3% of molasses), addition of 0.375 g MgSO4, 0.25 g(NH4)2SO4, 0.25 g urea and 0.25 g K2HPO4 as inorganic nitrogen source and inorganic salts, the ratio of material to water is 1:1, microbial inoculation quantity is 16%,fermentation temperature is 33.2?, fermentation time is 86.6 h. Under the best conditions, the total protein content reaches 57.57%, 17.42% higher than that of before fermentation; True protein content of 53.65%, 24.59% higher than that of before fermentation; The viable count achieves 3.6×109 cfu/g; Urease activity was reduced by 92.41%; Macromolecular protein is degraded into 20 KDa small molecule protein; Most of the antigen protein is degraded.(3)Optimum fermentation conditions of fermented soybean meal by Bacillus subtilis?Saccharomyces cerevisiae JM2 and Lactobacillus fermentum through single factor experiment and response surface optimization is concluded: charge 25 g(91% of soybean meal, 7% of bran, 2% of molasses), addition of 0.375 g MgSO4, 0.25 g(NH4)2SO4, 0.25 g urea and 0.25 g K2HPO4, the ratio of material to water is 1:1, inoculation quantity is 16.4%, 33.8 ? fermentation temperature is 33.8 ?, fermentation time is 74.5 h. Under the best conditions, the protein content reaches 59.15%,20.30% higher than that of before fermentation; True protein content of 55.21%, 27.95% higher than that of before fermentation; The viable count achieves 6.3 × 109 cfu/g; Urease activity was reduced by 85.06%; Macromolecular protein is degraded into 20 KDa small molecule protein; most of the antigen protein has been effective degradated.Research shows that three compound strains fermentation mode of Aspergillus oryzae and Saccharomyces cerevisiae JM1, Aspergillus carbonarius and Saccharomyces cerevisiae JM1, Bacillus subtilis and Saccharomyces cerevisiae JM2 and Lactobacillus fermentum can improve the nutritional value of soybean meal, degrade macromolecular protein and antigen protein, reduce the activity of urease, effectively increase the nutrients of products(protein content and the viable count), and improve the utilization rate of the soybean meal, is suitable for soybean meal fermentation of industrial production with the fermentation process of wine, aroma or sour flavor.