Screening Of The Lactobacillus Used For Silage Fermentation And Preparation Of Its Starter Cultures

Artificial feed have added a lot of chemical synthesis material, using synthetic feed poultry, toxic substance which accumulates in the animal body, would through the food chain to human body, such a threat to human health. The use of Lactobacillus fermentation of silage can solve this type of food safety issues, In the south of China, there are plenty of green forage resources, by Lactobacillus on forage silage, can improve food security and feeding value. This paper, from the plants filtering out fine Lactobacillus, develops a special starter cultures for silage forage.1.8suspected lactic acid bacteria are isolated from kimchi and natural silage forage by the means of presenting or dislodging dissolved calcium. Based on acid production experiment and acid resistance test, we get two high-yield strains PL6and CL3, Suitable for as silage inoculant, and they are initially identified to be the plant genus Lactobacillus and milk Streptococcus.2. Take advantage of the synergies between the two strains to determine the ratio of the mixed fermentation. That if PL6:CL3=2:1,they can maximize their physiological functions; and when they are fermented36h, the pH value of the fermentation liquor is up to3.62, which is lower than the others’pH value.Take two mixed lactic acid bacteria as inoculants, we make the fermentation tests of different forage, to detect the changes of the number of viable cells lactic acid bacteria, pH, and nutrients (dry matter, ash, crude fat, crude fiber, amino nitrogen) in the fermentation process. Comparison with raw material, we compare the pros and cons of lactic acid bacteria fermentation and natural fermentation comprehensively. Studies have shown that the inoculants had no significant effect ash content. Lactic acid bacteria fermented forage indicators are:pH of3.95to4.13, crude fat increased by1.05%～1.83%, crude fiber decreased from6.64%to13.23%, amino acid nitrogen content increased from1.85%to2.04%. The natural fermentation of forage in the pH is from4.7to4.8, so the fat increased has a lesser increasing extent.,Cellulose reduced by2.06%to7.18%, the increase in ammonia nitrogen is within1%. Therefore, it can be drawn that the forage grass inoculated with the composite strains fermented forage quality is better than natural fermentation of forage, and it apply to different forage grass.3. The best conditions of the mixed strains PL6proliferation culture is obtained by single factor experiment and orthogonal experiment and that is,3%glucose,1%beef extract,0.5%K2HPO4, initial pH value of6.2, the culture temperature is37℃, inoculum size of5%, Add4%tomato juice, cultured24h in this condition, viable cells reached8.75×109CFU/mL. The strains CL3proliferation optimum conditions, that is.2%glucose,1%peptone,0.5%K2HPO4, the initial pH value of6.5, the culture temperature is33℃, inoculum size of5%,add7.5%carrot juice, in this conditionincubated for24h, the number of viable cells reached10.5×109CFU/mL.Besides, It is determined that simultaneously using the composite protective agent in the freeze-drying process for:the5%trehalose,7.5%sodium glutamate,4%glycerol. After that drying the number of Lactobacillus reached5.79×1010CFU/g。...