2007 Volume 53 Issue 2 Pages 111-117
This study was carried out to screen lactic acid bacteria that produce active dietary enzymes, such as amylase, lipase, phytase, and protease, using a two-step process in pigs. We isolated a total of 210 and 132 strains of bacteria, grown under aerobic and anaerobic conditions, respectively, in Man Rogosa Sharpe agar containing 0.13% bile after treatment of intestinal samples at pH 3 for 30 min. From fecal samples, a total of 134 aerobic and 111 anaerobic strains were isolated in the same manner. In the second screening test, we selected four strains that produced four dietary enzymes from isolates obtained in the first screening test. Each strain was characterized as lactobacilli based on the following criteria: rod shape, negative for catalase, Gram positive, and lack of acute oral toxicity in mice. Of these four strains, we finally selected Lactobacillus spp. PSC101, which was resistant to pH 3 for 8 h and grew in the presence of 1% bile. In summary, Lactobacillus sp. PSC101 may be a strong probiotic candidate in swine due to its resistance to both acid and bile, its production of dietary enzymes that promote animal growth, and its non-toxic nature in mice.