Isolation and identification of Homolactic bacteria from Solanum melongena L. with antibacterial activity that improve vegetable fermentation

Abstract

The aim of this work was the isolation and identification of lactic acid bacteria with homolactic metabolism from eggplant; the lactic acid production and antibacterial activity were adopted as selected criteria to be included in the elaboration of fermented carrots as starter cultures. Between 50 isolated colonies, 14 were identified as lactic acid bacteria with homolactic metabolism, but only lactic acid bacteria identified phenotypic and genotypic as Lactobacillus plantarum were effective to produce cellular death and inhibit biofilm formation of five pathogenic bacteria. L. plantarum SB1 and SB2 were included in carrot fermentation on the basis of the best lactic acid production, antibacterial activity as well as the lowest C4 compounds and H2S formation. The scalded process was not enough effective to reduce Gram negative bacteria, but the addition of the selected bacteria isolated from eggplant to fermentation was effective to reduce all Gram negative population at 7 day. The big finding of this work was the isolation and identification of L. plantarum SB1 and SB2 from eggplant that could adapted in an different ecological niche and their addition to fermented carrots increase stability and microbiological safety of final product, preventing infectious diseases, with optimal sensorial attributed.