Biodiversity and Multifunctional Features of Lactic Acid Bacteria Isolated From Table Olive Biofilms.
Benítez-Cabello A, Calero-Delgado B, Rodríguez-Gómez F, Garrido-Fernández A, Jiménez-Díaz R, Arroyo-López FN
Front Microbiol. 2019. doi: 10.3389/fmicb.2019.00836
COMMENT: This work studies lactic acid bacteria biodiversity in table olive biofilms, and identifies some strains with potential application as starters for industrial production.
Industrial table olive processing and production is a multivariate process that includes acidification and salting that are influenced by microorganisms. These bacterial populations strongly determine the quality of the final product but the composition of these microbiomes is still poorly understood since the fermentation process still occurs spontaneously.
Knowing the microbiome composition involved in table olive preparation would be of use to make the process more predictable. Suitable microorganism mixes replicating this natural microbiome could be selected to be used as starter cultures.
In this work the researchers used a multidisciplinary approach to identify lactic acid bacteria (LAB) biodiversity in olive biofilms. First of all, they carried out a molecular genotyping of 554 isolates from different processing methods and olive varieties. The 16 most predominant genotypes were statistically clustered and identified by 16S sequencing. Lactobacillus pentosus accounted for 85% of the total identified isolates, showing high diversity.
These predominant genotypes were subjected to several tests analyzing salt resistance, optimal pH for growth and auto-aggregation. Probiotic potential tests were also carried out to analyze the resistance to gastric and pancreatic digestion, the pathogen inhibition capacity and the antibiotic susceptibility. These tests were the basis of a multivariate analysis that allowed clustering the genotypes in three great phenotypes, with some strains with potential application as multifunctional starters.