Laboratory domestication of Lactiplantibacillus plantarum alters some phenotypic traits but causes non-novel genomic impact.

AIMS: Laboratory domestication has been negligibly examined in lactic acid bacteria (LAB). Lactiplantibacillus plantarum is a highly studied and industrially relevant LAB. Here, we passaged L. plantarum JGR2 in a complex medium to study the effects of domestication on the phenotypic properties and the acquisition of mutations. METHODS AND RESULTS: Lactiplantibacillus plantarum JGR2 was passaged in mMRS medium (deMan Rogossa Sharpe supplemented with 0.05% w/v L-cysteine) in three parallel populations for 70 days. One pure culture from each population was studied for various phenotypic properties and genomic alterations. Auto-aggregation of the evolved strains was significantly reduced, and lactic acid production and ethanol tolerance were increased. Other probiotic properties and antibiotic sensitivity were not altered. Conserved synonymous and non-synonymous mutations were observed in mobile element proteins (transposases), ß-galactosidase, and phosphoketolases in all three isolates. The evolved strains lost all the repeat regions and some of the functions associated with them. Most of the conserved mutations were found in the genomes of other wild-type strains available in a public database, indicating the non-novel genomic impact of laboratory passaging. CONCLUSIONS: Laboratory domestication can affect the phenotypic and genotypic traits of L. plantarum and similar studies are necessary for other important species of LAB.

Isolation, characterization and comparative genomics of potentially probiotic Lactiplantibacillus plantarum strains from Indian foods.

Lactiplantibacillus plantarum is one of the most diverse species of lactic acid bacteria found in various habitats. The aim of this work was to perform preliminary phenotypic and genomic characterization of two novel and potentially probiotic L. plantarum strains isolated from Indian foods, viz., dhokla batter and jaggery. Both the strains were bile and acid tolerant, utilized various sugars, adhered to intestinal epithelial cells, produced exopolysaccharides and folate, were susceptible for tetracycline, erythromycin, and chloramphenicol, did not cause hemolysis, and exhibited antimicrobial and plant phenolics metabolizing activities. The genetic determinants of bile tolerance, cell-adhesion, bacteriocins production, riboflavin and folate biosynthesis, plant polyphenols utilization, and exopolysaccharide production were found in both the strains. One of the strains contained a large number of unique genes while the other had a simultaneous presence of glucansucrase and fructansucrase genes which is a rare trait in L. plantarum. Comparative genome analysis of 149 L. plantarum strains highlighted high variation in the cell-adhesion and sugar metabolism genes while the genomic regions for some other properties were relatively conserved. This work highlights the unique properties of our strains along with the probiotic and technically important genomic features of a large number of L. plantarum strains.