宋河大曲中醋酸菌的分离鉴定及产酸特性

Isolation and identification of acetic acid bacteria and acid-producing property from Songhe Daqu

对宋河大曲中的醋酸菌进行分离鉴定并研究耐酒精和产酸特性。共分离得到7株醋酸菌,经形态特征观察和生理生化试验,初步鉴定归2个属3个种,1株未知。2个属分别为葡糖杆菌属和醋杆菌属,3个种分别为氧化葡糖杆菌(Gluconobacter oxydans),巴氏醋杆菌(Aceto-bacter pasteurianus)和醋化醋杆菌(Acetobacter aceti)。氧化葡糖杆菌和醋化醋杆菌是宋河大曲中的主要醋酸菌。醋杆菌在产酸过程中可耐受含量为5%vol^11%vol的酒精,氧化葡糖杆菌的产酸性能受含量为9%vol^11%vol酒精。醋杆菌和氧化葡糖杆菌产酸快,30℃培养20h后,可迅速产酸,44h后趋近稳定,最低pH值可达4.2以下。

Acetic acid bacteria from Songhe Daqu were isolated and identified,and the ability of tolerance to alcohol and acetic acid production were further studied.7 Acetic acid bacteria were isolated and identified as Gluconobacter oxydans,Acetobacter pasteurianus and Acetobacter aceti through morphological characteristics and physiological-biochemical characteristics except one unknown strain.G.oxydans and A.aceti are dominant acetic acid bacteria in Songhe Daqu.The ethanol tolerance of Acetobacter was in range from 5%-11% vol during acetic acidproduction,and that of G.oxydans was between 9%vol and 11%vol.Acetobacter and G.oxydans started to produce acetic acid rapidly after fermentation for 20 h and reached steady state after 44 h at 30℃.The minimum pH value was below 4.2.