Isolation, Identification And Characteristics Of Aerogen From Explosion Bags Of Soy Sauce

Soy sauce is an condiment produced through the fermentation of soybean (soybean meal) and wheat (bran) using Aspergillus, yeasts and bacteria; contains rich amino acids, carbohydrates, vitamins and other nutrients. Production cycle of soy sauce is long and the microorganisms in workshop are complicated, if the sterilization and filling environment not control well, will cause soy sauce suffered secondary pollution, resulting in "bulging bag" phenomenon in shelf life, serious damage the interests of businesses and consumers.In this study, swelling bags and normal soy sauce as the main material, study after bulging bags of the soy sauce what has the main indicators changed. Isolated and identified and characteristics of aerogen, but also studies major workshop and process of soy sauce to analyze of microbial strains similar as aerogen in different months. The results as follows:1. After soy sauce swelling bags, the color was deepened and a little precipitation occurs; pH increased by0.23to0.67, the content of amino nitrogen and reducing sugar decreased by0.1～0.14g/L,0.014～0.13 g/100mL.2. Are not isolated yeast and mold from swelling bags of soy sauce; By different morphological a total of10kinds of bacteria are isolated:J1, J2,J3,J4, J5, J6,J7, J8,J9, J10; gas production experiments confirmed by Ji, J4and J6combination can production more gas similar to bulging bag of soy sauce. According to morphological, physiological and biochemical characteristics and16S rDNA, identified Ji is Bacillus subtilis, J4is Bacillus subtilis subsp.Natto and J6is Lactobacillus pobuzihii.3. J6strain is difficult to cultivate, the optimal culture conditions were determine, results show that the optimal incubation time is36h and the best medium is soy sauce medium.9%salinity could prevent Ji strain’s growth, and11%salinity could prevent J4strain’s growth, J6strain can still grow when salinity is16%. When pH reduced to4.5can prevent the growth of three kinds of strains. At a temperature of120℃and100℃at least heat15min,25min in order to kill J1and J4strains. At a temperature of65℃heat25min could killed J6strains.4. Using4%salinity of NA and liquid soy sauce medium investigate the bacteria from the air of fermentation workshop, filing workshop. Results showed that:The main microbe of fermentation room is mold, the maximum amount of Bacillus which similar to Ji and J4strains is104cfu/m3, and containing lactic acid bacteria which similar to J6strains. The amount of Bacillus which similar to Ji and J4strains about100cfu/m3and containing lactic acid bacteria which similar to J6strains In filling workshop.5. Survey the mash, sedimentation tank, mature oil storage tank, end product tank four process of bacteria, the results of gas production experiments showed that:The sample from mash and mature oil storage tanks and end product tank all product gas, mature oil is most serious. From sedimentation tank only isolated bacillus which similar to J1and J4strains have103cfu/mL. But after delivery to the mature oil tank, the concentration of lactic acid bacteria and bacillus microbes which both similar to aerogen significantly increased to104cfu/mL. After a secondary sterilization transported to the end product tank the concentration of lactic acid bacteria is300cfu/mL or more, and also contains bacillus. So from the sedimentation tank to the end product tank had contaminationed by aerogen.