宋河酒曲中产淀粉酶芽孢菌的分离鉴定及产酶特性

Identification and Properties of Amylase-producing Bacillus Isolated from Songhe Distiller's Yeast

为了有效控制宋河酒曲的制曲过程和发酵进程,对宋河酒曲中产淀粉酶芽孢菌进行了分离鉴定并研究筛选菌株的产淀粉酶特性。结果表明:从宋河酒曲中共分离到12株产淀粉酶芽孢菌,均属革兰氏阳性杆状菌,初步鉴定归为1个属5个种,即芽孢杆菌属(Bacillus)、坚硬芽孢杆菌(Bacillus firmus)、枯草芽孢杆菌(Bacillus subtilis)、地衣芽孢杆菌(Bacillus licheniformis)、凝结芽孢杆菌(Bacillus coagulans)、巨大芽孢杆菌(Bacillus megaterium),其中,坚硬芽孢杆菌是宋河大曲产淀粉酶芽孢菌的数量优势菌群,获得1株地衣芽孢杆菌SQ2为中温型高产淀粉酶菌株,其液态发酵产酶特性为37℃培养,前24h产酶较弱,此后,酶活力迅速上升,72h达到最大值为89μg/(mL.min),产酶旺盛期发生在菌体成熟期和衰亡初期,产酶过程pH值先稍偏酸性后接近中性。

Amylase-producing bacilli isolated properties were studied to effectively control the from Songhe Distiller＇s yeast were identified and their starter making process and fermentation process. The results showed that 12 bacillus strains which could produce amylase were isolated and identified as Bacillus firmus, Bacillus subtilis , Bacillus licheni f ormis , Bacillus coagulans and Bacillus megaterium , which belonged to genus of Bacillus. The B. firmus was the dominant amylase-producing bacillus in Songhe Daqu. Strain SQ2 was obtained as a high producing amylase bacillus by determining transparent circle, its properties of producing amylase brothing under 37℃ were showed as follows： amylase-producing activity kept minimum in first fermenting 24 hours, gradually raised after 24 hours, reached primary stabilizing value to 72 hours, and decreased gently after fermenting 72 hours, the maximum value of amylase activity could reach 89 μg/（mL·min）, the maximum amylase production occurred at the stage of strain maturity and decline growth. The pH value kept slightly acid and normal level in the course of producing amylase.