摘要
以自然接种的瓣曲为研究对象，应用示踪和基于基质特性组合的菌种筛选技术，筛选出适合其酿造特性的分离株N017。通过形态学观察和26srDNA、ITS序列的分子生物学鉴定，该分离株为Aspergillus oryzaet，命名为AoryzaeSZPl7。该菌株的中性蛋白酶和α-淀粉酶的酶学性质研究表明，中性蛋白酶的最适反应温度为40℃，20℃-40℃时比较稳定，最适反应pH值为7．5，耐酸性较强，C矿和M一对其具有激活作用，Fe3＋和Fe2＋其具有抑制作用。α-淀粉酶的最适反应温度为60℃，低于50℃比较稳定，最适反应pH值为6．0，pH值〉7．5时易失活，各种金属离子对其酶活影响较小。
The flora of naturally cultured Pixian＇horse-bean koji was anatomized. By screening technique of integrating the tracer with the culture substrates characteristics, strain No 17 was obtained. The isolate was identified belonging to Aspergillus oryzae according to the results of morphology and molecular classification of 26S rDNA and ITS, and named as A.oryzae SZP17. The enzymatic characteristics related to brewing properties such as neutral protease and a-amylase were measured. The optimal temperature and pH for neutral protease were 40℃ and 7.5, respectively. The neutral protease remained better stability between 20℃---40℃, and had strong acid-resistance, stimulated by Cu2＋ and Zn2＋, whereas inhibited by Fe3＋ and Fe2＋. The optimal temperature and pH for α-amylase were 60℃ and 6.0, respectively. The a-amylase remained better stability under 50℃, and metal ions used in present study had less effects on the activities.
出处
《中国酿造》
CAS
北大核心
2010年第5期30-34,共5页
China Brewing
基金
四川省重点科技项目(07SG111-009)
关键词
筛选
鉴定
郫县豆瓣瓣曲
A.oryzae
酶学性质
screening
identification
Pixian＇ horse-bean koji
A.oryzae
enzymatic characteristics
