Abstract: Based on their distinctive colonial morphology when co-cultured in MRS agar containing different carbon sources, two selective enumeration methods, namely difference method and chromatic aberration method, were established for Lactobacillus plantarum ST-Ⅲ and Leuconostoc mesenteroides BD1710 in co-culture. The reliability of these two methods could meet the requirements for selective counting of individual strains. The difference method was more suitable for research with high precision requirement owing to its higher average detection rate (97.2％ vs 95.4％ for ST-Ⅲ, 96.4％ vs 94.0％ for BD1710) compared with the chromatic aberration method, whilst the chromatic aberration method was superior in operability and cost and could provide factories with a fast way to determine viable bacterial counts in related products.

Key words: Lactobacillus plantarum; Leuconostoc mesenteroides; colonial morphology; selective enumeration

摘要： 基于植物乳杆菌ST-Ⅲ和肠膜明串珠菌BD1710在添加不同碳源的MRS固体培养基上的菌落形态差异,建立2株菌共培养时的2种选择性计数方法,分别为差值法和色差法。结果表明:2种方法均能够满足选择性计数的要求,且差值法中植物乳杆菌ST-Ⅲ和肠膜明串珠菌BD1710的平均检出率(97.2％和96.4％)均略高于色差法(95.4％和94.0％),因此差值法更适用于对精确度要求较高时数据的采集,而色差法具有操作简便和成本较低的优势,更适用于工厂进行快捷的活菌数量检测。

关键词: 植物乳杆菌; 肠膜明串珠菌; 菌落形态; 选择性计数