The Separation, Identification And Application Of Bacteria From The Traditional Fermented Products

In the research strains such as Lactic acid baeteria, Staphylococcus were isolated and screened from the traditional ferrnented meat product. After capacity of acid and growth were tested,3 strains of Lactic acid baeteria and 1 strain with excellent characteristics were selected and preliminary identified. As starter the srtains were applied to the fermented sausage and the physico–chemical properties were studied. The report included several parts as followed.1. 43 stains of Gram–positive and 24 stains of Gram–positive cocci were isolated from the fermented sausgae,Chinese sausage and ham with MRS agar and MSA agar. Based on the standards of screening Lactie acid bacteria and Staphyloc- occus of the fermented meat product,three stains of Lactie acid bacteria including L11, L21 and L31 three stains of Grma–positive cocci such as C11, C13, C16, C18, C23 were screened. The 3 stains of Lactic acid bacteria acidificaction rate and acidifying capacity were better than ohters. And they did not produce slime, H2O2, CO2 from glucose, NH3 from agrinine. They also had no decarboxylase activity and can resist nirtiteand and NaCl. In addition, C23 displayed eatalase–positive,nitrate reduction,proteinase and lipase activity.2. Testing the growth capacity of all strains and acidifying capacity of latic acid bacteria at different temperature, we found that the best temperature for the 3 latci acid bacteria is 30–35℃. L31's best temperature is 30℃and at 25℃it has good expression. The others'best temperature is 35℃. At 15℃the growth capacity of all strains were obviously affected. At low temperature(15℃) L21 and C23 had better growth capacity. In consideration of the capacity of resisting nirtiteand and NaCl, L11, L21, L31, C23 were selected to identify.3. On the basis of phenotype and physiological biochemical characteristic L11 was preliminary identified as Pediococcus pentosaceus, L21 was preliminary identified as lactobacillus curvatus, L31 was preliminary identified as lactobacillus pentosaceus, C23 was preliminary identified as Staphylococcus simulans.4. The selected strains were used to produce the fermented duck. As starter the latci acid bacteria were added to ferment sausage. At last, Pediococcus pentosaceus and latci acid bacteria were selected to be starter. Orthogonal test was applied to confirm the best process as Pediococcus pentosaceus and lactobacillus pentosaceus used. The optimum process was the inoculation of 108cfu/g, incubation at 35℃, relative humidity 90%, Pediococcus pentosaceus:lactobacillus pentosaceus as 1:1. When the Staphylococcus simulans was added, the optimum process was the inoculation of 108cfu/g, incubation at 35℃, relative humidity 90%, Pediococcus pentosaceus: lactobacillus pentosaceus: Staphylococcus simulans as 1:1:1.5. Based on the optimum process, fermented duck was produced after the tests of microbial succession, physico–chemical properties. As the fermented action of microorganism, the content of nirtiteand was depression in acceleration. Microbial enzymes played important role in the proteolysis and lipolysis and prevented the oxidation of lipid significantly.