Development of a selective and differential medium for effective isolation of Pectobacterium carotovorum from soft rot-infected agricultural products

Abstract

Pectobacterium carotovorum subsp. carotovorum causes soft rot in vegetables and fruits by degrading pectin in plant tissues. Existing selective media such as crystal violet pectate (CVP) often fail to differentiate P. carotovorum from other bacterial strains. In this study, we developed a novel selective and differential medium, BO, incorporating myo-inositol, D-cellobiose, and pectin as key carbon sources, along with bromocresol green as a pH indicator. The BO medium demonstrated significant selectivity and specificity by producing distinct yellow-green colonies for P. carotovorum. Furthermore, pH measurements showed that P. carotovorum rapidly acidifies the BO medium, enabling clear differentiation from other bacterial species. Through 16S rRNA sequencing, we confirmed the successful isolation of P. carotovorum from soft rot-infected Chinese cabbage. This medium enhances the early detection and management of soft rot disease in agricultural products, offering an efficient tool for distinguishing P. carotovorum from competing microorganisms.