胀包常温酸奶中产气微生物的分离鉴定与特性研究

Isolation,Identification and Characteristics of Gas Generation Microorganisms in Swollen Long Life Drinking Yogurt

为探究常温酸奶产品的胀包问题,对胀包产品中的微生物进行分离纯化和产气特性验证,共得到5株产气性质分离株,经鉴定均为地衣芽孢杆菌,并对其耐高温、耐酸性特性进行研究。实验结果显示,分离菌株对90℃以下的温度具有较高的耐受性,WH_(2)分离株在95℃加热时活性明显高于其他菌株(P <0.5),并在100℃时仍可生长;分离株在pH为4.0时均可生长繁殖,在pH为2.0时除WH_(2)分离株生长均受到显著抑制(P<0.5)。酸性条件下耐高温实验显示,高温条件和酸性环境协同作用时,分离株的耐受性比之单一条件作用时明显降低(P <0.5)。实验为产品杀菌工艺的优化提供理论依据。

In order to solve the problem of long life drinking yogurt products,the microorganisms in the bulging products were separated,purified and gas generation characteristics were verified.A total of 5 gas-producing isolates were obtained,all of which were identified as Bacillus licheniformis.The results of the high temperature and acid resistance test showed that the isolates have a high tolerance to temperatures below 90°C,and the isolate WH_(2) is significantly more active than other isolates when heated at 95°C(P<0.5).In addition,it can also grow at 100°C.The isolates can grow at pH 4.0,and the growth of isolates except WH_(2) isolate are significantly inhibited at pH 2.0(P<0.5).The high temperature resistance test under acidic environments showed that when high temperature conditions and acidic environments work together,the tolerance of isolates is significantly lower than that under single conditions(P<0.5).The test provides a theoretical basis for the optimization of the product sterilization process.