Molecular structure of the Lactobacillus plantarum sucrose utilization locus: Comparison with Pediococcus pentosaceus

Structure of the sucrose utilization locus in a Lactobacillus plantarum typ e strain was studied using PCR and Southern hybridization. Restriction map analysis revealed its high similarity to the sequenced sucrose utilization locus of Pediococcus pentasaceus pSRQ1. The L. plantarum locus proved to co ntain oppositely oriented scrA and the scrBRagl operon, but not agaS. The L . plantarum sucrase gene (scrB) was partly sequenced. A higher (98.6%) homo logy was revealed between scrB than between the 16S rRNA genes of L. planta rum and P. pentosaceus, suggesting horizontal transfer of the sucrose utili zation locus between the genera of lactic acid bacteria. Amino acid sequenc e analysis showed that the ScrB proteins of the two species belong to a sub family of glycosyl hydrolase family GH32 which includes various beta -fruct osidases.