Dados do Trabalho

Título

SPECIES-SPECIFIC IDENTIFICATION AND THE PRESENCE OF THE BACTERIOCIN GARVICIN Q GENE IN Lacticaseibacillus rhamnosus STRAIN HN001

Introdução

Strains from the Lacticaseibacillus casei group (L. casei, L. paracasei and L. rhamnosus) have beneficial probiotic effects on human and animal health, and they are a minor but important component of the human gut microbiota. The three species are phylogenetically and phenotypically related, so they are difficult to discriminate. Lacticaseibacillus rhamnosus is a highly consumed probiotic because it produces short-chain fatty acids, modulates the immune system, prevents gastrointestinal diseases, balances the intestinal microbiota, and restores the mucosal barrier. Several beneficial health effects have been reported for infants and mothers due to the consumption of the probiotic Lacticaseibacillus rhamnosus strain HN001, including reduced risk of eczema in infants and reduced risk of gestational diabetes and postnatal depression in mothers. This study aims to attest the taxonomic classification of the commercial strain L. rhamnosus HN001 and to evaluate the presence of the genes encoding the bacteriocin Garvicin Q.

Material e Métodos

A robust species-specific PCR identification assay was employed targeting mutL gene. The species L. rhamnosus had its taxonomic classification confirmed. Previous in silico analysis highlighted that the genes garQ and garI encode the bacteriocin Garvicin Q in Lacticaseibacillus rhamnosus HN001 genome and in twelve other strains of L. rhamnosus. The presence of the garQI operon was evaluated by PCR using a new designed primer pair.

Resultados e Discussão

L. rhamnosus HN001 was positive for the presence of garQI amplicon, while L. rhamnosus LGG and L. rhamnosus ATCC 7469 were negative for the garQI amplicon. Sequencing of the garQI amplicon found that the fragment corresponds to the garQI region of Garvicin Q, that is present in genome of just 13 strains of L. rhamnosus, including HN001.

Conclusão

This report is a pioneer in the detection and sequencing of Garvicin Q gene in L. rhamnosus strain HN001.