食品科学 ›› 2008, Vol. 29 ›› Issue (10): 395-398.

• 生物工程 • 上一篇    下一篇

基因组改组技术对L-乳酸产生菌耐热性的影响

 王立梅, 齐斌   

  1. 常熟理工学院生物与食品工程学院;
  • 出版日期:2008-10-15 发布日期:2011-12-08

Improvement of Thermotolerance of L-Lactic Acid Producing Strains by Genome Shuffling

 WANG  Li-Mei, QI  Bin   

  1. School of Biotechnology and Food Engineering,Changshu Institute of Technology,Changshu 215500,China
  • Online:2008-10-15 Published:2011-12-08

摘要: 采用紫外线与亚硝基胍(NTG)两种诱变方法获得用于基因组重组的出发菌株,应用灭活的多亲原生质体再融合获得活性融合子的方法,有效地提高了基因组改组后的筛选效率。采用低pH值平板和碳酸钙平板连续筛选的方法,筛选得到干酪乳杆菌改组菌株,具有较强耐酸性能,够在pH3.6MRS平板上生长繁殖,产酸量为原始菌株的3.4倍,发酵温度提高到40℃,摇瓶发酵结果表明,改良菌株的代谢途径未发生变化。

关键词: L-乳酸, 干酪乳杆菌, 基因组改组

Abstract: In this study,wild-type L actobacillus rhamnosus was treated respectively by ultraviolet (UV) irradiation and nitrosoguanidine (NTG) to obtain mutant strains,and then they were subjected to recursive protoplast fusing. The acid tolerance and thermotolerance of the wild-type L actobacillus rhamnosus are improved by genome shuffling. A library that is more likely to yield positive results was created by using fusing the lethal protoplasts obtained from the strains treated by both UV irradiation and heat. After three rounds of genome shuffling,the strains that could grow at pH 3.6 were obtained. The L-lactic acid production is 3.4 times of that of the wild-type strain and the temperature is increased to 40 ℃. The results of shake-flask fermentation showed that the shuffled strains have the same pathway producing L-lactic acid as the wild-type one.

Key words: L-lactic acid, Lactobacillus rhamnosu, sgenome shuffling