活性乳酸菌制品中乳酸菌计数条件的优化研究

Research on optimization of culture conditions for lactobacteria counting in activated lactobacteria products

[目的]探索一种乳酸菌计数的选择性培养基,优化培养条件,以便真实反映产品中乳酸菌的数量。[方法]利用涂布法和平板倾注法,采用不同的培养条件对计数结果进行对比研究。[结果]于改良TJA培养基中加入硫酸多黏菌素(100000IU/L)和放线菌酮(10mg/L),以抑制样品中可能污染的杂菌,同时对乳酸菌无影响。[结论]乳酸菌计数的优化条件为:采用平板涂布法,在CO2烛缸法条件下培养48h,可最大限度地检出样品中的乳酸菌数量。该实验条件简单,方法便于掌握,结果准确,易于推广使用。

[Objective] This experiment is to seek a kind of selective medium applied in Lactobacteria counting, and to optimize the culture conditions so that the results could reflect the true numbers of lactobacteria in products. [Methods] Study and contrast the different lactobacteria counting results obtained from different culture conditions respectively with the rubbing method and the plate pouring method. [Results] Good results have been obtained by adding Polymyxin B Sulfate (100000 IU/L) and cycloheximide (10mg/L) to the TJA medium to hold back the growth of possibly polluted bacteria and not to affect the growth of lactobacteria at the same time. [ Conclusions] The best conditions of lactobacteria counting are as following: The largest lactobacteria number in products can be detected with the rubbing methods,under the CO2 conditions caused by candle buming in a jar within the 48h's culture time. With the simple experiment conditions and accurate results,the method is easy to master and popularize.