Isolation of phytase and bacteriocin producing lactic acid bacteria from fermented food for potential use as probiotecs.

Abstract

Altogether 13 strains of bacteria were isolated from different kinds of fermented food products; i.e. 2 isolates from kimji, 2 isolates from fermented wild spider flower, 2 isolates from fermented Chinese cabbage 1 isolate from yogurt and 6 isolates from 2 samples of yogurt drink. Biological plate assay toward growth of Lactobacillus platarum TISTR850, a nisin-sensitive strain, revealed that only 4 isolates can produce obvious clear zone around their colonies. Others were grown with either narrow clear zones or none at all. From Gram staining, all four strains were G(+) rod. Comparison of the nisin-like activity among the 4 isolates showed that strains KV1 and YT contained similar level of activities. KV1 reduced growth of TISTR850 down by 63% while YT did so by 65%. However, testing for the ability in producing phytate digesting enzyme clearly showed that only KV1 harbored such a function.The strain was found to have optimum growth at 35oC and pH6.0. The phytase enzyme produced under such a condition was 0.15 unit. Growth as well as bacteriocin and phytase production of the strain KV1 under various conditions were determined. This strain was shown to be a good candidate for use as probiotic, especially in animal feed.