产广谱乳酸菌素菌株的选育、鉴定及其发酵特性研究

在传统发酵食品中分离得到产酸茵株50株,从中筛选出一株产广谱乳酸菌素菌株,经鉴定是植物乳杆菌。实验对该菌株产乳酸菌素发酵培养基的优化结果为:牛肉膏2%,酵母粉0.75%,蔗糖2.5%,柠檬酸三铵0.2%,乙酸钠0.5%,K_2HPO_40.4%,MgSO_4·7H_2O 0.058%,MnSO_4·4H_2O 0.025%;最佳发酵条件为:35℃,初始pH值6.0,添加2%的吐温80。在此条件下,菌株的抑菌圈直径可达3.15 cm。

Screening,identification and optimization of fermentation conditions for bacterial strain producing lactobacillin

One bacteria strain secreting lactobacillin was isolated from the traditional fermentative food. According to its appearance, biochemical characteristics and 16S rDNA gene sequence homology analysis, it was identified as Lactobacillus plantarum . The optimum medium for the lactic acid bacteria producing lactobaeillus were as follows： beef extract 2 %, yeast extract 0.75 %, sucrose 2.5 %, triammonium citrate 0.2 %, sodium acetate 0.5 %, K2 HPO4 0.4 %, MgSO4 ·H2O 0. 058 %, MnSO4 ·4H20 0. 025. The optimum fermentation conditions were： fermentation temperature 35℃, initial pH value 6.0, and adding 2 % tween-80. Under above conditions the diameter of bactcriostatic ring could reach 3.15 cm.