Molecular taxonomy and genomic characterization of genes regulated by Quorum Sensing pathways in isolates of Lactic Acid Bacteria from different food matrices

Abstract

The lactic acid bacteria (LAB) are a paraphyletic group that is related to several food matrices ecosystems. In the cocoa spontaneous fermentation LAB composes the main diversity of bacteria in the entire fermentation process. Since the Ph.D. Project 17/13759-6, supported by FAPESP, focus on Quorum Sensing (QS) influence on cocoa fermentation and aims to develop a defined bacterial cocktail to standardize the fermentation by selecting LAB strains whose QS activity was detected, the taxonomic approach to well-characterize the LAB isolates is very important because this approach is fundamental to relate the strain to its origin, habitat and physiology, which directly impacts the selection of novel candidate microorganisms for applications in standardized industrial fermentations. On the other hand, as LAB are well-recognized by possessing QS Two-component systems (QS-TCSs) that are key-systems in QS pathways, a genomic analysis of LAB genomes through Whole-Genome Sequencing (WGS) will be useful to identify in silico the putative coding sequences related to these QS-TCSs, which will be helpful in two ways: (i) to design the starter culture proposed in the project 17/13759-6 and, (ii) to compare the LAB taxonomy scheme based on phylogenetic markers with the entire markers sequences retrieved from the assembled LAB genomes. (AU)