米多霉素的生物检定法与HPLC测定法

为定量测定米多霉素含量,建立了一种新型的生物检定法.通过考察12种红酵母的最低抑制质量浓度（MIC）,筛选出合适的敏感菌.研究了抑菌圈的直径与米多霉素浓度的关系,比较了米多霉素对检定菌的抗菌活性与其对粉霉菌的抗菌活性的关系,对比了该生物检定法与高效液相色谱(HPLC)法.结果表明,红酵母AS 2.166为最适检定菌,其抑菌圈的直径与米多霉素浓度的对数值呈显著的线性关系,相关系数为0.999 4.米多霉素对检定菌的抗菌效价与其对黄瓜粉霉菌的抗菌效价具有高度的一致性.该生物检定法与HPLC测定法均具有较好的准确度和精密度,可替代高效液相色谱法,用于米多霉素发酵过程的产量检测.

Quantitative determination of mildiomycin by bioassay and HPLC

A novel agar diffusion bioassay method for quantitative determination of mildiomycin was established.After an optimal sensitive microorganism was screened from 12 species of rhodotorula rubra with the indication of minimum inhibitory concentration(MIC),the relationship between the inhibition zone sizes and the mildiomycin concentrations was investigated,and the effectiveness of mildiomycin against the sensitive microorganism was compared with that against powdery mildew diseases of cucumbers.The accuracy of the proposed method was contrasted with high performance liquid chromatography(HPLC) analysis.Results show that rhodotorula rubra AS 2.166 is the optimum test organism.The common logarithm of mildiomycin concentrations is significantly linear with the inhibition zone sizes with correlation coefficient of 0.999 4.The effectiveness of mildiomycin against rhodotorula rubra is coincident with that against powdery mildew diseases of cucumbers.The bioassay method and HPLC analysis are precise and accurate.The bioassay method is applicable for mildiomycin determination during the fermentation process as the substitute for HPLC analysis.