丁酸梭菌对肉仔鸡饲料加工过程及消化道环境的耐受性研究

本试验通过模拟肉仔鸡饲料制粒条件及其消化道环境,研究丁酸梭菌在饲料制粒过程中及在肉仔鸡消化道内对不良环境的耐受性。试验分别对丁酸梭菌的温度、压力、人工胃液及肠道消化酶耐受性进行评价。高温耐受性试验:将含丁酸梭菌试验饲粮在85℃的条件下分别处理2.5、5.0、7.5 min,对照组不作处理。高压耐受性试验:将含丁酸梭菌试验饲粮分别在0.20、0.30、0.40 M Pa压力下处理5 min,对照组不作处理。人工胃液耐受性试验:将含丁酸梭菌试验饲粮在p H分别为2.00、3.00、4.00的人工胃液中处理48 min,对照组以p H为7.00的磷酸盐缓冲液(PBS)替代人工胃液。肠道消化酶耐受性试验:将含丁酸梭菌试验饲粮用p H为3.00的人工胃液处理48 min后,再在肠道消化酶混合液中处理198 min,对照组以p H为7.00的PBS替代肠道消化酶。每组均设3个重复。试验结束后平板计数法检测试验饲粮的丁酸梭菌活菌数,计算存活率。结果表明:85℃高温处理2.5、5.0、7.5 min后丁酸梭菌的存活率分别为70.43%、52.69%、46.35%;0.20、0.30、0.40 M Pa压力下处理5 min后丁酸梭菌的存活率分别为64.38%、87.14%、101.74%;p H为2.00、3.00、4.00的人工胃液处理48 min后丁酸梭菌的存活率分别为113.27%、123.07%、78.52%;经肠道消化酶混合液处理198 min后丁酸梭菌的存活率为47.71%。结果提示,丁酸梭菌能够耐受肉仔鸡饲料加工过程中的高温、高压环境,对人工胃液有较好的耐受性,但对肠道消化酶的耐受性较低。

Tolerance of Clostridium butyricum in Feed Processing and Digestive Tract Environment of Broilers

The aim of this study was to investigate the tolerance of Clostridium butyricum ( C. butyricum) to adverse unsuitable environment in the process of pellet and in the digestive tract of broilers by simulating the condition of pellet and the environment of the digestive tract of broilers in vitro. The tolerance of C. butyricum to high temperature, high pressure, artificial gastric juice and intestinal digestive enzyme were evaluated, re?spectively. High temperature tolerance test:the experimental diet which contained C. butyricum was treated for 2.5, 5.0 and 7.5 min at 85 ℃, respectively, and the control group had no treatment. High pressure tolerance test: the experimental diet which contained C. butyricum was treated for 5 min at 0, 0.20, 0.30 and 0.40 MPa, respectively, and the control group had no treatment. Artificial gastric juice tolerance test: the experimental diet which contained C. butyricum was treated for 48 min in artificial gastric juice ( pH=2.00, 3.00 and 4.00, respec?tively) and phosphate buffered saline ( pH=2.00, as control group) , respectively. Intestinal digestive enzyme tol?erance test: the experimental diet which contained C. butyricum was firstly treated for 48 min in artificial gastric juice ( pH=3.00) , and then treated for 198 min in intestinal digestive enzyme juice and phosphate buffered saline ( pH=7.00, as control group) , respectively. Each group had three replicates. After the test, the viable count of C. butyricum was measured by plate counting method, and the livability of C. butyricum was calculated. The results showed that the livability of C. butyricum was 70.43%, 52.69%and 46.35%by treating for 2.5, 5.0 and 7.5 min at 85℃, respectively. After treatment at 0. 20, 0. 30 and 0.40 MPa for 5 min, the livability of C . butyricum was 64.38%, 87.14%and 101.74%, respectively. The livability of C. butyricum was 113.27%, 123.07%and 78.52%by treating for 48 min in artificial gastric juice with the pH of 2.00, 3.00 and 4.00, respectively. The livability of C. butyricum was 47.71% after digestive enzyme juice treatment for 198 min. The results indicate that C. butyricum can tolerate high temperature and high pressure environment in feed processing, and has a better tolerance for artifi?cial gastric juice, but has a lower tolerance for intestinal digestive enzyme.