The screening, Behavior and Application of the Microorganisms in Traditional Fermented Foods

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In Laurel Forest and Southeast Asian countries, many kinds of people produced the traditional fermented foods. The naturally fermented foods of cereals (wheat flour, rice), Tea, Meat, fish and soybean produced at home for family consumption, and relied to enzyme action of their natural bacterial flora. In modern times, more people in the all over the world are leaving the countryside to live in towns, and consuming the convenience foods, which produced in factory. After this time, we will lose the traditional processing technologies of foods and the great value of traditional foods. The collagenase present' in the culture supernatant of Bacillus subtilis FS-2 which was isolated from fish sauce was purified. The purification procedure was comprised of the concentration of culture filtrate by ultrafiltration, liquid chromatography on ion-exchange columns DEAE-Sephalose CL-6B, CM-cellulose, butyl Toyopearl 650 M, and finally, fast liquid chromatography on gel filtration Sephadex-G75. The enzyme was purified to homogeneity and had a molecular weight of about 125,000, which was seemingly composed of two similar subunits of 60,000. Besides insoluble collagen, the purified collagenase degraded gelatin with a maximum activity at pH 9 and a temperature of 50"*"C.Purified enzyme was stable in a wide range of pH (5-10) and had only 15% and 35% activity lost at 6000 and 65"*"C, respectively. Slightly inhibited by inhibitors such as EDTA, tripsin inhibitor, iodoacetamide and iodoacetic acid, the enzyme was severely inhibited by 2-mecarptoethanol. The hydrolysis of gliadin and casein as allergenic proteins by enzyme from B.subtilis FS-2 suggested this bacterium could be used the preparation of low allergenic foods.