一株嗜热脂肪芽孢杆菌的筛选及其产酶特性研究

Screening of a Geobacillus stearothermophilus Strain and Study on Its Enzyme-Producing Characteristics

从高温大曲中分离得到了一株产淀粉酶和蛋白酶的嗜热芽孢杆菌ZJY-1,研究了菌株ZJY-1的生长特性和产酶特性,并应用于强化麸曲探究其价值。经鉴定分析,菌株ZJY-1为嗜热脂肪芽孢杆菌(Geobacillus stearothermophilus),其最适生长pH为7.0,有良好嗜热性,最适生长温度为55℃,且在65℃高温下仍生长良好;菌株酶活力检测结果表明,不同发酵时间菌株功能酶活力存在差异,淀粉酶活力最高达到了133.5 U/g±12.5 U/g,蛋白酶活力最高为175.4 U/g±4.8 U/g;通过制备强化麸曲试验表明,ZJY-1麸曲具备分泌蛋白酶和淀粉酶能力,生物量指标可达到5.7×10^(10)±2.8×10^(9) CFU/g。本研究丰富了大曲微生物菌种资源,为高温曲发展方向提供了参考价值。

A strain ZJY-1 with amylase and protease producing ability was isolated from high-temperature Daqu.The growth characteristics and enzyme producing characteristics of strain ZJY-1 were analyzed,and its value in the production of fortified Fuqu was explored.Strain ZJY-1 was identified as Geobacillus stearothermophilus.Its optimum growth pH was 7.0,its optimum growth temperature was 55℃,and it grew well under the temperature of 65℃.The enzyme activity test results of strain ZJY-1 showed that its functional enzyme activity was different at different fermentation stages;the amylase activity reached 133.5±12.5 U/g,and the protease activity reached 175.4±4.8 U/g.Fortified Fuqu made with strain ZJY-1 had the ability to secrete protease and amylase,and the biomass index reached up to 5.7×10^(10)±2.8×10^(9) CFU/g.This study has enriched the microbial resources for Daqu making,and has provided reference for the development of high-temperature Fuqu.