| Summary: | 碩士 === 國立中興大學 === 畜產學系 === 92 === The purpose of this study was to evaluate the probiotic characterization wich ß-glucanase gene transferred Lactobacillus reuteri Pg 4 strain （T-Pg 4）, with isolated form GI tract of poultry. Acceding to in vitro characteristics assay, in the capability of tolerance to acid experiment, the Pg 4 and T-Pg 4 strain viable counts maintained 108 cfu/mL after one and three hours under incubating in pH 2.0. The capacity of bile tolerance of T-Pg 4 strain were 87.7%. For adhesive ability assay, T-Pg 4 strain could adhere to epithelium cell of broiler. After incubating for 6 hours, the viable counts of T-Pg 4 strain were 109 cfu/mL. It showed that only Pg 4 grew faster than T-Pg 4 strain, then other characterization were similar by in vitro. Pg 4 strain could not resist Erythromycin、Gentamicin and Penicillin, but T-Pg 4 strain could. The transgenic ß-glucanase modified Lactobacillus reuteri Pg 4 strain have to be probiotic characterization. After the above in vitro test, T-Pg 4 strain have probiotic characterization, and have ß-glucanase activity（1.32 U/mL）by colorimeteric method and enzyme radial diffusion method. T-Pg 4 strains were taken orally by SPF broiler experiment. Results showed that Lactobacillus counts in the intestinal content and excreta of the treatment group had at least 106cfu/g on days 3 and 7. But none could be detected in the control group. The exited T-Pg 4 also confirmed by colony-PCR methods. Those T-Pg4 cell showed having ß-glucanase activity by colorimeteric method and enzyme radial diffusion method. The results showed T-Pg 4 were able to pass through and to survive in the GI tract of chicken. Further, the effect of the T-Pg 4 strain powder（108 cfu/g） on the growth performance of broiler was studied under conventional feeding environment. The results showed Lactobacillus counts in the content of crop、ileum and caecum of T-Pg 4 group were higher than the control group on 3, 7, 28 and 42 day-old. T-Pg 4 strain powder supplement in barley diet, has lower digesta viscosity and significantly improved the body weight gain（P<0.05）and feed conversion（P<0.05）. The exited T-Pg 4 also confirmed by colony-PCR methods. Those T-Pg4 cell showed having ß-glucanase activity by colorimeteric method and enzyme radial diffusion method. To summarize, evaluated by in vitro and in vivo assay, the T-Pg 4 strain could survive in the broiler GI tract with activity of ß-glucanase. T-Pg 4 strain powder supplement in barley diet could decrease digesta viscosity and significantly improved the body weight gain（P<0.05）and feed conversion （P<0.05）.The T-Pg 4 strain could be as a multi-function candidate strain for probiotic use in broiler.
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