Research And Development Of A Novel Microbial Ecological Agent

The pollution of drug residues in the products of livestock and poultry, and drug-resistant harmful bacteria has become a critical issue concerning the health of the people and the export restriction of livestock and poultry in our country. Probiotics is the living microbial agent which was made of normal intestinal microbe, Its application can make better the micro-flora environment of gut by its preponderant flora action and biological antagonistic action. Furthermore probiotics can supply normal microorganisms in the quantity and types in the intestinal. Thirdly, it will enhance immune function,and promote digestion and absorption of nutrients, so as to prevent and cure the disease. Chinese herbal medicine can significantly improve the body immunity, thus plays a role in disease prevention and treatment. Therefore, probiotics and Chinese herbal medicine has become better alternative choices of animal feed additive than antibiotics. Studies have shown that probiotics can have a variety of enzymes to promote absorption and utilization of the active ingredients of Chinese herbal medicine, meanwhile, rich nutrition in herbs can promote the proliferation of probiotics microorganisms. On the basis of the synergistic effect of probiotics and Chinese herbal medicine, in this study, they were combined together to develop a novel microbial ecological agent.By means of selective culture, Gram staining, spore staining, sugar fermentation tests, the classical physiological and biochemical tests, acid resisting tests and bile salt resisting tests, A Lactobacillus sp. with strong tolerance to acid and bile salt was successfully isolated and identified from the healthy pigs intestinal and named as Lactobacillus sp strains L5. By employing single-factor test and orthogonal test, the medium composition and culture conditions of the Lactobacillus Sp. strain L5 were determined and optimized. Furthermore, the medium composition and culture conditions of a Bacillus subtilis strain and a Saccharomyces cerevisiae strain of our laboratory preserved were optimized too. In order to improve the storage resistance ability of the probiotics and enhance the survival rate when the probiotics go through stomach, microcapsules of Lactobacillus sp. Strain L5 were prepared by using microcapsule technology; and bacterial powder of the Bacillus subtili strain was made by using spray drying method; and yeast powder of the Saccharomyces cerevisiae strain was made by using low-temperature vacuum drying method. The astragalus mongholicus and malt were mill ground by superfine pulverizer to and mixed with the probiotics preparation to obtain our required microbial ecological agent.In order to verify the application effect of our microbial ecological agent, preliminary studies were conducted in the farming of pig-breedings. The results showed that the novel microbial ecological agent obtained by this study can improve animals production performance, enhance their immunity, increase the effectiveness of culture.