| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lactic bacterium variant which has improved oxygen resistance and in which a riboflavin transporter gene is wholly or partially inactivated. <P>SOLUTION: Mutation is induced in Lactobacillus gasseri OLL 2716 strain by using disparity mutagenesis at first, and a variant having improved survivability (improved oxygen resistance) in the presence of the oxygen is screened by preserving the obtained variant at a low temperature in an oxygen-filled condition. As a result, it is clarified that the mutation in the riboflavin transporter gene takes part in the enhancement of the oxygen resistance. The inventors has succeeded in the creation of the variant having the improved survivability when preserved at the low temperature in the oxygen-filled condition by inducing the mutation in the riboflavin transporter gene in the bacterium of Lactobacillus gasseri or the bacterium of Lactobacillus delbrueckii subsp. bulgaricus. <P>COPYRIGHT: (C)2011,JPO&INPIT |
