Sorbitol gene cluster in B. breve and insertion mutant growth curve. a) Locus map showing the comparative analysis of the gene cluster putatively involved in the utilization of the sugar alcohol sorbitol in certain B. breve chromosomes. All genes are coloured coded based on their function. The percentage of similarity based on BLASTP alignment and the alcohol dehydrogenase-encoding gene targeted for the genetic insertion experiment are indicated. b) Diagram showing the growth curves of B. breve JCM 7017 wild-type and B. breve JCM 7017–1848 insertion mutant on Rogosa modified MRS (mMRS) with the addition of lactose and sorbitol 0.5% over 24 hours.