一株传统牦牛酸乳源醋酸杆菌鉴定及产酸条件优化

Identification of a Strain of Acetobacter from Traditional Yak Yoghurt and Optimization of Acid Production Conditions

为了鉴定一株传统牦牛酸乳源疑似醋酸杆菌菌株的种属及确定其最佳产酸条件,利用形态观察试验、生理生化试验和16S rRNA基因序列测定试验对其进行鉴定,并在不同培养基、乙醇浓度、培养温度和pH条件下进行培养,优化产酸条件。结果表明,菌株CS-63鉴定为蒲桃醋酸杆菌(Acetobacter syzygii);在发酵培养基、25℃下、乙醇浓度5%、pH 4.5条件下产酸量最高,产量为14.7 g/L。

In order to identify the species of a suspected Acetobacter strain from traditional yak yoghurt and determine its optimal acid production conditions,morphological observation test,physiological and biochemical test and 16S rRNA gene sequencing test are used to identify the strain.The strain is cultured in different culture media,ethanol concentration,culture temperature and pH value to optimize the acid production conditions.The results show that the strain CS-63 is identified as Acetobacter syzygii.The acid yield is the highest of 14.7 g/L under the conditions of fermentation medium,25℃,ethanol concentration of 5%and pH value of 4.5.