生料醋醅中优势醋酸菌的筛选及其产酸特性

从生料醋醅中筛选出优势产酸醋酸菌,经过形态学和16S rDNA生物学鉴定,确定分离纯化出的菌株为巴氏醋杆菌(Acetobacter pasteurianus)。通过菌落计数器计得的菌落数和高效液相色谱法测定的产酸类型和产酸量,绘制生长曲线和产酸曲线。结果显示,巴氏醋杆菌的生物量在16 h达到最大。发酵过程产生的有机酸中,乳酸质量浓度最高,可达2.1 mg/mL,发酵116 h时乙酸含量达到1.8 mg/mL。草酸质量浓度最低,范围为0.4~1.23 mg/100 mL。柠檬酸质量浓度没有明显变化,维持在0.08~0.11 mg/mL之间。琥珀酸在发酵过程中质量浓度从0.04 mg/mL增加到0.31 mg/mL,主要起调和口感的作用。本研究旨在为生料醋质量评价提供数据参考。

Screening of Dominant Acetic Acid Bacteria in Raw Material Vinegar and Acid-production Characteristics

Acid-producing bacteria were screened from raw vinegar. The isolate and purified strain was identified as Acetobacter pasteurianus by morphological and 16S rDNA. Based on the number of colonies calculated by the colony counter and the type and amount of acid produced by high-performance liquid chromatography,the growth curve and acid production curve were drawn. The results showed that the biomass of A. pasteurians reached its maximum at 16 h. Among the organic acids produced in the fermentation process,the mass concentration of lactic acid was the highest,reached 2.1 mg/mL,and the acetic acid content reached 1.8 mg/mL during 116 h of fermentation. The mass concentration of oxalic acid was the lowest,range from 0.4 to 1.23 mg/100 mL.There was no significant change in the mass concentration of citric acid,which remained between 0.08 and 0.11 mg/mL.During the fermentation,the mass concentration of succinic acid increased from 0.04 mg/mL to 0.31 mg/mL,which mainly played a role in regulating the taste. The purpose of this study was to provide data reference for the quality evaluation of raw vinegar.