酵子中一株醋酸菌的分离鉴定及产酸条件研究

Isolation,Identification and Acid Production Conditions of a Dominant Acetic Acid Bacteria Strain in Jiaozi

从我国传统面团发酵剂酵子中分离、筛选得到一株醋酸菌菌株A-3,根据菌株的形态、生理生化特征,结合16SrRNA基因序列分析,最终确定菌株A-3为热带醋杆菌(Acetobacter tropicalis)。利用单因素试验对其产酸条件进行优化,结果表明:在接种量6%、pH值5.5、转速180~200r/min、乙醇体积分数3%~5%、温度37℃的条件下菌株A-3的产酸量可达到31.1g/L。试验结果为传统发酵剂中功能菌种资源的开发、面团发酵剂的改良以及微生物对面团特性的影响等研究提供参考。

A dominant acetic acid bacteria(AAB)strain A3 was isolated and screened from Chinese traditional dough starter Jiaozi.According to the morphological,physiological,biochemical and 16S rRNA gene sequence characteristics,strain A-3 was identified as a strain of Acetobacter tropicalis.The acid production conditions of AAB strain A-3 were also optimized by single factor experiments.The results showed that the fermentation conditions were as follows:inoculum amount at 6%,pH 5.5,rotation rate with 180 to 200 r/min,ethanol content with 3%~5%(V/V)and temperature at 37℃.The acid production in the fermentation environment could reach 31.1 g/L.The results will not only lay foundation for the exploitation of AAB strains from dough starters,but also be helpful to improve the dough starters and explore the effects of microorganisms on dough fermentation characteristics.