Molecular diversity of lactic acid bacteria from cassava sour starch (Colombia)

Lactic acid bacteria and more particularly lactobacilli and Leuconostoc, ar e widely found in a wide variety of traditional fermented foods of tropical countries, made with cereals, tubers, meat or fish. These products represe nt a source of bacterial diversity that cannot be accurately analysed using classical phenotypic and biochemical tests. In the present work, the ident ification and the molecular diversity of lactic acid bacteria isolated from cassava sour starch fermentation were assessed by using a combination of c omplementary molecular methods: Randomly Amplified Polymorphic DNA fingerpr inting (RAPD), plasmid profiling, hybridization using rRNA phylogenetic pro bes and partial 16S rDNA sequencing. The results revealed a large diversity of bacterial species (Lb. manihotivorans, Lb. plantarum, Lb. casei, Lb. hi lgardii, Lb. buchneri, Lb. fermentum, Ln. mesenteroides and Pediococcus sp. ). However, the most frequently isolated species were Lb. plantarum and Lb. manihotivorans. The RAPD analysis revealed a large molecular diversity bet ween Lb. manihotivorans or Lb. plantarum strains. These results, observed o n a rather limited number of samples, reveal that significant bacterial div ersity is generated in traditional cassava sour starch fermentations. We pr opose that the presence of the amylolytic Lb. manihotivorans strains could have a role in sour starch processing.