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

在桂冠森林和东南亚国家，许多民族生产传统的发酵食品。谷物（小麦粉、大米）、茶叶、肉类、鱼类、大豆等家庭自制的自然发酵食品，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生活在城镇，消费工厂生产的方便食品。在这段时间之后，我们将失去传统食品的加工技术和传统食品的巨大价值。对从鱼露中分离得到的枯草芽孢杆菌FS-2培养上清中存在的胶原酶进行了纯化。纯化过程由超滤浓缩培养滤液、DEAE-Sephalose CL-6B、CM-cellulose、butyl Toyopearl 650 M离子交换柱液相色谱、凝胶过滤Sephadex-G75快速液相色谱组成。该酶纯化至均匀性，分子量约为125,000，似乎由两个相似的亚基60,000组成。除不溶性胶原外，纯化后的胶原酶还能降解明胶，在pH为9、温度为50℃时活性最高。纯化后的酶在很宽的pH范围内（5-10）都很稳定，在6000℃和65℃时，酶活性分别仅损失15%和35%。EDTA、tripsin抑制剂、碘乙酰胺、碘乙酸等抑制剂对该酶的抑制作用较弱，2-甲基甲醇对该酶的抑制作用较强。枯草芽孢杆菌FS-2酶水解麦胶蛋白和酪蛋白为致敏蛋白，提示该菌可用于制备低致敏性食品。

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.