传统馒头老面中醋酸菌的鉴定及产酸条件优化

Identification of acetic acid bacteria in fermenting agent of Chinese steamed bread and optimization of fermentation conditions

自晋南地区传统馒头发酵剂(老面)中筛选出一株产酸量较高的醋酸菌(Q2534),对其进行了菌种鉴定及产酸量优化研究。通过16S r DNA测序分析初步鉴定为热带醋酸杆菌(Acetobacter tropicalis)。在单因素实验的基础上通过响应面分析法继续对发酵产酸条件进行优化,确定该菌株的最优发酵条件为:温度32℃,转速140 r·min^(-1),p H6.0,乙醇体积分数3.4%(v/v),在此条件下产总酸量可达26.74 g/L。其结果对传统主食馒头发酵剂中醋酸菌资源的发掘及应用具有一定的意义。

A high acid producing acetic acid bacteria （Q2534）was screened from traditional steamed bread fermentation agent in the south of Shanxi.The identification and acid production optimization have been done to it. It has been identified as Acetobacter tropicalis based on 16S rDNA method. On the basis of single factor experiments,the best fermentation conditions and medium composition were optimized by response surface analysis method.The best fermentation conditions were as follows, temperature 32 ℃, rotation rate 140 r·min^-1, pH6.0 and alcohol content 3.4% （v/v）.Under these conditions,the yield of acetic acid of this bacteria can reach 26.74 g/L.The results have some effects on exploitation and application of the resource of acetic acid bacteria that got from traditional fermenting agent of Chinese steamed bread.