黄精发酵体系中植物乳杆菌的分离鉴定和MTT法活菌快速检测研究

目的从黄精发酵体系中分离鉴定益生菌,并建立其快速检测方法。方法通过形态学观察、革兰氏染色、16S rRNA基因序列测定和同源性分析对分离的菌株进行鉴定,采用MTT法建立快速检测方法。结果从鲜黄精发酵体系中分离获得一株乳酸菌,鉴定为植物乳杆菌(Lactobacillus plantarum);建立了植物乳杆菌检测的MTT法,发现检测最佳波长为545 nm,适宜染色时间为2 h,最低检测度为活菌浓度为107 CFU/mL,在活菌浓度为7×10;~3×10;CFU/mL范围内,植物乳杆菌样品活菌浓度与545 nm处OD呈现良好的线性关系。结论从黄精发酵体系中分离纯化了一株植物乳杆菌,可以通过MTT法快速检测其活菌总数,为益生菌活菌快速检测提供了参考。

Isolation and identification of lactic acid bacteria from fermented broth of polygonatum and fast detection of live bacteria by MTT method

Objective To isolate and identify probiotics from the fermented broth of polygonatum,and to establish a rapid detection method.Methods The isolated strains were identified by morphological observation,Gram staining,16 S rRNA gene sequence determination and homology analysis,and the rapid detection method was established by MTT method.Results A strain of lactic acid bacteria was isolated from the fresh polygonatum fermentation broth and was identified as Lactobacillus plantarum.MTT method for the detection of Lactobacillus plantarum was established.The study found that the best wavelength was 545 nm,the suitable staining time was 2 h,and the minimum detection of the concentration of live bacteria was 107 CFU/mL.In the range of the concentration of live bacteria from 7×10;CFU/mL to 3×10;CFU/mL,live bacteria concentration of the Lactobacillus plantarum and the OD at 545 nm showed a good linear relationship.Conclusion A strain of Lactobacillus plantarum was isolated and purified from the fermented broth of polygonatum.The total number of live bacteria can be quickly detected by the MTT method,which provides a reference for the rapid detection of probiotics.