COMPARATIVE GENOMIC ANALYSIS AND PHYLOGENETIC STUDIES OF THE UBIQUITOUS Lactobacillus curvatusGROUP

TERÁN, L; RAYA RR; FADDA S,; MONIQUE ZAGOREC; CHAMPOMIER-VERGÈS, M.; CHAILLOU, S

San Miguel de Tucuman

Simposio; V Simposio Internacional de Bacterias Lácticas-SIBAL CERELA- CONICET; 2016

Lactobacillus curvatus is mainly associated with fermented meat products and vacuum-packaged refrigerated meat. It was also isolated from fish, cheese, and sushi. This species belongs to the L. sakeiclade of psychrotrophic Lactobacillus and is phylogenetically closely related to Lactobacillus sakei, Lactobacillus fuchuensis and Lactobacillus graminis. L.curvatusstrains have biotechnologic potentials,such as bacteriocin production, to be applied as a starter and a bioprotective culture for meat products.In this work, we performed in silico comparative genome analysis of the L. curvatusgroup, including five strains isolated from different sources: the newly sequenced FLEC03, isolated from vacuum packaged beafcarpaccio; CRL705, from an Argentinian artisanal dry sausage; NRIC0822, from Japanese sushi; DSM20009, the type strain, isolated from milk and F16#9, from the human gut. The comparison was also extended to the closely related L. sakei 23k and L. graminisDSM20719. To assess the pangenomic diversity of this group, in terms of variability, we sought for strain-specific genes and, in terms of the core-genome, we studied the phylogenetic relation within this group. The sequences were ordered accordingly to the complete genome of L. sakei 23k. Manual annotation of all the strains was carried out using the Microscope Platform. Phylogenetic analyses were performed using progressive Mauve and Clonal Frame. Phylogenomic studies showed that L. curvatusclade is divided into two lineages, one of them is represented by strains DSM20019, F16#9, CRL705 and NRIC082, while the other is represented by FLEC03 strain, which is closer to the strain DSM20719 of L. graminisand to the strain 23k of L. sakei. This was confirmed with further analysis withmultilocus sequence typing (MLST) using the dnaK, ldhL, tufA and hemN genes and extending the study to others 29 strains of L. curvatus. Taking together all the L. curvatus strains studied, the core genome is constituted by 1345families of genes, which represents the 41.7% of the chromosome.Unlike L. sakei 23k, all L. curvatus -especially CRL705- and L. graminisDSM20719 present a wide repertoire of PTS systems for the uptake of sugars. We conclude thatthe L. curvatus group has a wide genomic variability, including significant strain-specific genes. L. curvatus is a ubiquitous species that has the ability to adapt and overcome different environmental conditions.