白贝自然发酵调味液中乳酸菌的分离鉴定及生物学特性的研究

以白贝自然发酵味液为分离源,分离得到26株疑似乳酸菌,经过菌落形态、菌体形态、生理生化实验、16s rDNA鉴定,确定3号菌株和6号菌株分别为植物乳杆菌和戊糖片球菌。分别对两种菌株的生长曲线、产酸能力、耐酸能力、耐盐能力等生物学特性考察。结果表明,两种菌株6 h后开始进入对数生长期,3号菌株和6号菌株分别于18 h和20 h后进入稳定期,3号菌株生长速度较6号菌株快,且进入稳定期后,3号菌株菌体浓度OD值达到1.73左右,6号菌株达到菌体浓度OD值达到1.56左右;两种菌株6h后,产酸速度加快,18 h后3号菌株菌液pH值达到3.5,6号菌株菌液pH值达到3.6,3号菌株产酸能力较强;两种菌株在pH值为3.5时,均有良好生长,3号菌株菌液浓度OD值达到1.742,6号菌株菌液浓度OD值达到1.597;两种菌株均能耐受3%～4%的盐,6号菌株的耐盐能力略强于3号菌株。两种菌株具有良好的产酸、耐酸和耐盐特性,为后续应用奠定了一定的基础。

Isolation and Identification of Lactic Acid Bacteria from Natural Fermented Sauce of Monetaria moneta and Study of Their Biological Characteristics

Twenty-six suspected lactic acid bacteria were isolated from naturally-fermented sauce of Monetaria moneta. After colony morphology, bacterial morphology, physiological and biochemical experiments and 16S rDNA identification, Lactobacillus plantarum and Tabacillus pentosae strains No. 3 and No. 6 were identified as Lactobacillus plantarum and Tabacillus pentosae respectively. The growth curve, acid production capacity, acid tolerance and salt tolerance of the two strains were investigated. The results showed that the two strains began to enter logarithmic growth phase after 6 hours, strain 3 and strain 6 entered stable phase after 18 hours and 20 hours, respectively. The growth rate of strain 3 was faster than that of strain 6, and the OD value of strain 3 reached about 1.73 and that of strain 6 reached about 1.56 after entering the stable stage. After 6 hours, the acid production rate of the two strains accelerated, and after 20 hours, the acid production capacity of strain 3 became stable, and the acid production capacity of the two strains was strong at pH 3.5. Both strains could tolerate 3%~4% of salt, and strain 6 had a slightly stronger salt tolerance than strain 3.