藤黄微球菌培养基优化及其对乳酸链球菌素浊度分析方法的改进

Cultivation Medium Optimization for Micrococcus luteus and Improvement of the Turbidimetric Bioassay of Nisin

乳酸链球菌素(Nisin)的效价一般以藤黄微球菌作为指示菌,可采用浊度法定量测定.在实验中发现,藤黄微球菌在基本培养基中生长缓慢,导致效价测定结果偏差较大.因此,通过单因素设计和正交设计对藤黄微球菌的培养基进行优化.实验结果表明,葡萄糖和K_2HPO_4可显著延长藤黄微球菌的对数生长期,而MgSO4促进藤黄微球菌生长的作用较弱.利用优化后的培养基测定Nisin效价,实验周期可明显缩短,测定结果偏差小、准确度高,Nisin的效价测定方法得到明显改善.

Nisin was commonly quantified by turbidimetric bioassay with Micrococcus luteus as the indicator microorganism.However,the low growth rate of M.luteus in the minimal medium was found to lead to relatively large deviation in quantification results.Therefore,single factor test and orthogonal array testing was used to optimize the cultivation medium of M.luteus.The results showed that glucose and K2HPO4 can significantly extend the logarithmic phase of M.luteus,whereas MgSO4 slightly promotes the growth of M.luteus.Using the optimized medium for the quantification of Nisin,not only the experimental period was obviously shortened,the accuracy and precision was also improved.