3种传统发酵蔬菜制品中乳酸菌分离鉴定及其发酵特性分析OA

To develop pure strain starter suitable for Yunnan sour bamboo shoot fermentation,lactic acid bacteria(LAB)with excellent fermentation properties are isolated and screened from three traditional fermented vegetable products.Three strains of LAB named LAB1,LAB2 and LAB3 are isolated by MRS plate culture,the strains are identified by physiological and biochemical characteristics and 16S rDNA sequencing,fermentation and functional properties are analysed.The results show that LAB1 and LAB3 are Lactobacillus plantarum,LAB2 is Lactobacillus harbinensis.Strain LAB1 has strong acid producing ability,pH≤3.60 in the stable period,and can tolerate the environment of pH3.0 but the growth of LAB3 is inhibited in an environment with pH of 3.0,strains LAB1 and LAB3 has a strong salt tolerance and could adapt to the environment of 8%salt concentration,strain LAB2 has strong bile salt tolerance.The results show that the three strains has strong nitrite degradation ability,and the degradation rate is more than 99%after 24 hours of culture.All three strains have some antioxidant capacity,and the scavenging rates of DPPH radicals and ABTS+radicals are 9.13%～11.83%and 6.02%～8.37%respectively,the antioxidant activity of acellular extract is weak.The three strains are able to inhibit Escherichia coli and Staphylococcus aureus,and the diameter of inhibition zone is from 15.77 to 18.00 mm.The above results show that the strains LAB1 and LAB2 have excellent fermentation performance,and have the characteristics of nitrite degradation and bacteriostasis,having the potential to further prepare pure strain starter of sour bamboo shoots.