Isolation And Identification Of Probiotics For Poultry, Study On Enzymatic Properties And The Preliminary Application

It is a major problem to abuse antibiotics in stockbreeding now, researchers try tofind the replacer of antibiotics. Probiotics can be defined as nonpathogenicmicroorganisms. They were applied to feed as a new additive in recent years. Byplenty of practice and research, it was indicated that Bacillus spp. will had importantsignificance for the maintenance and growth in normal animals. It is known as one ofthe most potential sources of probiotics.According to the conventional method of measuring enzyme activity. 3 strains,including B,N and WS-3L, for an useful new probiotic addition were isolated frommicroorganisms, the intestine of healthy chicks and the soil. Using the universalprimers of bacteria, bacterial 16SrDNA fragments presented specific expansion.Molecular Biology of the strains were identified as Bacillus cereus, lactobacillus andBacillus licheniformis sp. By the method of optimization of culture conditions andmedium tests, the best medium was chosen, which consist of the initial 1% soybeanmeal, 0.5% fishmeal. 0.5% corn starch, 0.5% galactomannan, 0.5% NaCl.Meanwhile, the properties of microbial enzyme (α-amylase) produced by Bacillussp WS-3L were also obtained. The results showed that an extracellularα-amylase(AmyL)from a Bacillus sp WS-3L was purified 345 fold and had a recovery of 15.5%.It was optimally active at 45℃and pH values around 6.5 and showed stability at thetemperature below 40℃and pH 7.0～8.0. The amylase was inhibited by Cu²⁺,NH⁴⁺,Ag⁺,Hg⁺,EDTA and SDS. Raw com starch exhibited high adsorption of the enzyme.It was suggested that the stable enzyme was able to be obtained and applied very fastby corn starch chromatography.Through the design of chicks tests, the new addition, including probiotics andenzymes from the strains B,N and WS-3L, was proved to improve feed efficiency andpromote animal growth, and enhance the chicks resistance and reduce death and cullrate. Therefore, a new type of probiotics which has excellent development potentialcan improve the growth performance of the host.