Studies On Screening Of Highly Active Strains Of Compound Bacteria Culture And Optimization Of Solid Medium

In this study, the high biological activity of the bacteria was selected through the comparision of strain biomass, and then the best combination, optimum inoculation ratio and the best inoculum size were determined. Systemic optimization study of solid state fermentation medium and the optimum culture conditions of the best inoculum were made by single factor experiment and L9(34) orthogonal test. Moreover, the results were verified through animal feeding trial.Our results showed that yeasts BC, BY, BD and BR have obvious advantages in bacterial cells, growth peak, crude protein content, viable count and fermentation aroma. Fungus H3 was also significantly higher than other strains in characteristics such as biomass and ability of enzyme production. Therefore, fungus H3 with better performance may be selected as test strains. The optimization condition as follows:the best combination of complex strains(BC + BY + BR ), the best inoculation ratio( 2:1:1), the best production of inoculum(2.5%), and the best carbon source, nitrogen source and carbon nitrogen ratio of solid state fermentation medium were wheat bran , sesame-seed cake and rapeseed meal and 4:1. Optimum allocation of the solid-state fermentation medium was wheat bran(53.33%), corn flour(17.79%),corn bran(4.44%), rice bran 4.44%, rapeseed cake(10%) and sesame cake(10%). Viable count reached 15.25 billion cfu/g, peptide content was 6.032mg/g, and amino acid content was 178.96 mg / g under certain culture conditions (30℃, 36h, pH5.5, H2PO40.5%, MgSO40.1% ).Caprine feeding trial showed that diets supplemented with yeast culture complex would be helpful to the health status of sheep, achieved weight gain and weight gain, the weight gain of two groups of experimental sheep per day were increased by 20.0g, and 25.7g respectively under the condition of confinedness.