X射线对嗜热乳杆菌产L-乳酸的选育研究

Breeding study of Lactobacillus Thermophilics induced by X- ray for L- lactic acid production

摘要: 为了获得更适于工业生产的产L-乳酸菌株,提高生产效率。本文以X射线对嗜热乳杆菌（Lactobacillus thermophilus）进行诱变处理,通过碳酸钙-溴甲酚紫平板初筛结合摇瓶复筛的方法,最终获得稳定高产的突变菌株。结果表明:经X射线诱变得到的突变菌株SR7,平均发酵产酸量为22g/L,比原菌株产量提高了15.04%,且经过多次重复实验表明该菌株具有良好的遗传稳定性。

Abstract: In order to obtain a lactic acid bacteria strain to more suitable for industrial production and to improve the production efficiency. The Lactobacillus thermophilus which irradiated by X- ray were screened by calcium carbonate- bromocresol purple plate and submerged fermentation in shaking flask. The results showed that a stable high- yield mutant strain,named SR7,could produce 22 g / L of L- lactic acid on average with the yield increase of 15.04%,compared to the original strain.It was also proved that SR7 strain had good genetic stability by repeating experiments.