南岳茶油腐乳中乳酸菌的分离鉴定

Isolation and Identification of Lactic Acid Bacteria from Nanyue Tea Oil Sufu

豆腐乳是我国传统特色美食,也是乳酸菌的天然菌库。文章以寻求适宜人体的益生性乳酸菌为目标,采用溶钙圈法从南岳茶油豆腐乳中分离出6株乳酸菌,编号为RSP1~6。结果表明:6株菌均为球状乳酸菌,RSP5和RSP6可在pH 4.0、 11.0%NaCl、 0.35%胆盐条件下存活,RSP5的耐酸、耐盐能力最强;RSP6的耐胆盐、产酸能力最强,且生长活性最强、生长周期最短。将RSP5和RSP6菌株进行16S rDNA测序并构建系统发育树,发现RSP5、RSP6与戊糖片球菌亲缘最近,鉴定为戊糖片球菌。

Fermented foods such as sufu and pickles are not only the Chinese traditional specialties,but also the natural experimental materials for screening lactic acid bacteria.In this study,six strains of probiotic lactic acid bacteria were screened by the method of dissolving calcium circle from Nanyue tea oil sufu,which were named RSPL1-RSPL6.The six bacterial strain were carried on the study of physiological and biochemical properties.The results showed that the shape of six strains was globular.RSP5 and RSP6 have good physiological and biochemical properties,which were able to survive at pH4.0,salinity of 11%and bile salts at 0.35%.RSP5 had the strongest property of acid and salt-resistance.RSP6 has the strongest bile salt-resistance and acid production capacity and has the strongest growth activity and the shortest growth cycle.The RSP5 and RSP6 strains were sequenced by 16S rDNA and a phylogenetic tree was constructed.It was found that RSP5 and RSP6 were closest to P.pentosaceus,thus identified as Pediococcus pentosaceus.