乳酶生菌种脂肪酸组分的GC-MS检测分析

目的：建立气相色谱-质谱联用法测定乳酶生菌种的脂肪酸成分，并对各试样菌株间的同源性进行分析。方法：应用14%三氟化硼-甲醇法对菌株进行脂肪酸甲酯化，采用HP-5MS毛细管色谱柱（30 m×0.250 mm×0.25 μm），载气为氦气，程序升温（120℃，5 min；6℃·min^-1升至240℃，10 min；10℃·min^-1至260℃，2 min），进样口温度250℃，选择EI离子源，溶剂延迟3 min，质谱扫描m/z 35~450。结果：肠球菌属的菌株均具有十四碳烷酸、十六碳烷酸、十六碳烯酸、十八碳烷酸、十八碳烯酸及十九碳烷酸特征峰；批号为20100922和20101001的乳酶生片菌株与海氏肠球菌CGMCC1.595之间，6家生产企业的其他乳酶生片菌株与粪肠球菌140623和屎肠球菌CGMCC1.131之间，具有相似的气相色谱图及相近的脂肪酸组分比值。结论：本方法可用于乳酶生菌种的快速鉴定及同源性分析。

Objective: To establish a GC-MS method for the determination of fatty acids in lactasin strain,and to analyze the homogeneity of the strains of samples.Methods: 14% Boron fluoride-methanol solution was used to methyl-esterify the fatty acids of strains.HP-5MS capillary column (30 m×0.250 mm×0.25 μm) was used with temperature programming.The oven temperature was set at 120℃ for 5 min initially.Then it was raised to 240℃ at a rate of 6℃·min^-1 and was maintained for 10 min.In the end,the temperature was raised to 240℃ at a rate of 10℃·min^-1 and was maintained for 2 min.The injector temperature was 250℃.EI ion source was selected and the solvent was delayed by 3 min.The MS scanning was set at the range of m/z 35-450.Results: The characteristic peaks of tetradecanoic acid,pentadecanecarboxylic acid,hexadecenoic acid,octadecanoic acid,octadecenic acid and nonadecanoic acid were found in the strains of Enterococcus.The GC chromatograms and the ratios of the fatty acids of the strains of lactasin tablets(batch number:20100922 and 20101001) and Enterococcus hirae CGMCC 1.595 were similar.And the same phenomena was observed in other lactasin tablets strains of 6 production enterprises and Enterococcus And the same phenomena were observed in other lactasin tablets strains of 6 production enterprises and Enterococcus faecalis 140623,Enterococcus faecium CGMCC 1.131.Conclusion: The established method could be used for the rapid identification and homology analysis of lactasin strain.