不同温度及乙醇含量对生料醋醅中醋酸菌产酸能力的影响

从正常发酵的生料醋醅中分离、筛选得到一株醋酸菌,通过形态学、16S rDNA基因序列分析,确定菌株为巴氏醋杆菌。菌株发酵过程中,改变发酵温度和初始乙醇添加量,研究其对有机酸种类和含量的影响,为评价食醋品质提供参考依据。利用高效液相色谱检测样品,检测到的有机酸有草酸、乳酸、乙酸、柠檬酸,最高含量分别是2.5 mg/100 mL,5.0 mg/mL,3.4 mg/100 mL,0.17 mg/mL。在37,42,47℃这3个温度下最适宜有机酸生成的乙醇添加量分别是4%,6%,2%,最利于醋酸菌发酵的温度是42℃。

Effect of Different Temperature and Ethanol Content on Acid Production Ability of Acetic Acid Bacteria in Raw Material Vinegar

A strain of Acetobacter was isolated and screened from the normal fermented raw material vinegar,and the strain was identified as Acetobacter pasteurianus by morphological and 16S rDNA gene sequence analysis.During the fermentation of the strain,the fermentation temperature and initial ethanol addition were adjusted to studied its effect on the type and content of organic acid,which provided a reference for evaluating the quality of vinegar.The samples were detected by high performance liquid chromatography.The organic acids detected were oxalic acid,lactic acid,acetic acid and citric acid,and the highest content were 2.5 mg/100 mL,5.0 mg/mL,3.4 mg/100 mL,and 0.17 mg/mL respectively.The optimum ethanol content at different temperatures 37,42,47℃ was 4%,6%,2%.The optimum fermentation temperature for acetic acid bacteria was 42℃.