| Excellent lactic acid bacteria strains were screened from traditional fermented foods of Guizhou minor ities, including sour meat, sour soup, cured beef, pickles and Lan cai, were used to screen lactic acid bacteria. They would be used as starters to shorten production time and cost of traditional fermentational meat food and produce functional fermented meat food with special flavor of Guizhou. The mainresults were as follows:115 strains were isolated from Guizhou characteristics fermentation products, which were mainly spherical and rod-like. Among them 86 strains had similar characterics to lactic acid bacteria through the preliminary physiological and biochemical test. Thirteen strains reduced cholesterol rate of 15%~20% and 5 strains lowered cholesterol rate more than 20%. The Strain MT-4 cholesterol removal rate was 25.66%.Nine of the 13 strains did not produce mucus, H2 S, biogenic amines. The nine strains without amino acid decarboxylase activity produced acid without generating gas by ferment ation of glucose. The strains MT-4, MT-2, PJ-15, SR2-2, SQ-4, SQ-7, ST2-2, ST2-6, NR1-7 can tolerance gastrointestinal environment, salt and nitrite. The concentration of nitrite was tested by hydrochloric acid diammonium naphthyl.The strain SQ-4 degradated rate of nitrite of 72.874% and 97.166%, respectively after incubation of 12 h and 24 h, while the degradation rate of strain SR2-2, SQ-7, NR1-7, ST2-6, SQ-4 were all 95.816% after 24 h. The PJ-15 strain degradated rate of nitrite of 74.224%.By morphology, physiological and biochemical properties and phylogenetic based on the 16 S r RNA. The strains SR2-2, ST2-2 and NR1-7 were Lactobacillus plantarum. The MT-4 strain was Lactobacillus pentosus GUFHSL-69, which was registered in CCTCC under CCTCC No. M2016001, and strain SQ-4 was Lactobacillus paraplantarum GUF HSL-70, which was registered in CCTCC under CCTCC No. M2016002. These lactic acid bacteria strains can inhibit Staphylococcus aureu s and Escherichia coli. The strain SR2-2 was resistant to penicillin, while sensitive to cefazolin. The strain NR1-7 showed moderately sensitive to cefazolin. Strains showed no hemolysis on blood agar. After intragastric gavage, animals in each group activities were in their normal state, and had a good coat gloss. The appearance, feeding, limbs, drinking water, excretion were also no exception. The animals did not show any symptoms of toxicosis and death. The animal body weight gradually increased. Those suggested that the strains MT-4 and SQ-4 had no acute toxicity.Lactobacillus pentosus MT-4, Lactobacillus plantarum NR1-7 and Lactobacillus paraplantarum SQ-4 went into the stable phase after liquid culture of 15 h, while the pH was reduced to about 3.5. The three LAB strains showed no antagonism by cross line. 10% of skimmed milk powder were used as a anti-freeze agent, and the survival rate of the dry strain SQ-4 after vacuum freeze-drying was more than 93%. The viable count can reach up to 8.0 log CFU / g after preservation of 30 d under 4 ℃. Three lactic acid bacteria were added into pickle juice at the rate of 1:1:1, pH of which dropped to 3.55 after inoculation 18 h and the viable counts achieved to 8.73±0.26 log CFU/mL. Then pickle jucie was used as starer to ferment beef. The pre-cooking of pickle beef showed a good flavor and taste, while the color and texture were unsatisfactory. |
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