耐60℃高温乳酸菌的驯化及鉴定

Acclimation and identification of 60 ℃ thermotolerant Lactic acid bacteria

目的对本实验室保存的ATCC 4356菌株进行温度梯度诱变,从而获得1株耐高温乳酸菌。方法采用温度梯度方法诱变菌株;通过革兰染色和原子力显微镜观察诱变前后菌株革兰染色特性和形态及表面结构的变化;通过生理生化特性鉴定,判断诱变前后菌株是否发生种属变化。结果在45-60℃诱变过程中,随温度升高传代次数递增,但最终均能成功驯化和稳定传代。驯化前后菌株在产酸能力、形态特征、革兰染色和生理生化特性方面无显著性变化,表明该诱导菌株未发生种属变化;原子力显微镜观察结果表明诱导前后菌株表面形态存在差异。结论温度梯度诱变技术能够成功驯化耐60℃高温乳酸菌,从而扩大其应用范围。

Objective To gain a thermotolerant Lactic acid bacteria from the strain ATCC 4356 by the temperature gradient method.Method The temperature gradient method was used to mutate Lactic acid bacteria.Before and after mutagenesis,the Gram stain characteristics,morphology and surface structure were observed by Gram stain and Atomic Force Microscope（AFM）;Physiological and biochemical characterization were used to determine whether the strain′s species had any changes.Result During the mutagenesis process 45～60 ℃,the passage of the strains was increased along with the rising temperature,and finally the strains were acclimated successfully with the ability to passage stably;The acid production capacity,morphological characteristics,Gram stain,and physiological and biochemical characteristics of the strains had no significant changes after acclimation.Atomic force microscopy results showed that the strains before and after induction had a great difference in the surface structure and morphology.Conclusion Mutagenesis of temperature gradient method can successfully domesticate 60 ℃ thermortolerant Lactic acid bacteria,thus expanding its scope of application.