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

在月桂森林和东南亚国家，许多人生产传统的发酵食品。谷类(面粉、大米)、茶、肉、鱼、大豆等天然发酵食品在家中生产供家庭食用，依靠其天然菌群的酶作用。在现代，世界各地越来越多的人离开农村到城镇生活，消费工厂生产的方便食品。在这之后，我们将失去传统的食品加工技术和传统食品的巨大价值。对从鱼露中分离到的枯草芽孢杆菌FS-2菌株培养上清液中存在的胶原酶进行了纯化。菌液经超滤浓缩、离子交换层析DEAE-Sephalose CL-6B、CM-纤维素柱、丁基丰珠醇650M层析、Sephadex-G75凝胶层析等步骤得到纯化。该酶被纯化至均一，分子量约为125,000，似乎由两个相似的60,000亚基组成。除不溶性胶原蛋白外，纯化的胶原酶在pH为9、温度为50℃时对明胶具有最大的降解活性。纯化后的胶原酶在较宽的pH范围(5~10)内稳定，在6000℃和65℃时分别损失15%和35%的活力。该酶被EDTA、Tripsin抑制剂、碘乙酰胺和碘乙酸等抑制剂轻度抑制，被2-甲基甲基乙醇严重抑制。枯草杆菌FS-2菌株对醇溶蛋白和酪蛋白的酶解表明，该菌可用于制备低过敏性食品。

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.