Genome characterization of Leuconostoc pseudomesenteroides UTNElla29 isolated from Morus nigra (L.) fruits: A promising exopolysaccharides producing strain

Abstract

Lactic acid bacteria produce various natural polysaccharides that are secreted into the cellular matrix and bonded to the cell surface or released into the surrounding environment. Due to their broad applications in the food industry, the search for novel polysaccharide producer strains remains of interest. In this study, we report the genome sequencing and characterization of Leuconostoc pseudomesenteroides strain UTNElla29 isolated from Morus nigra (L.) fruits. Using in silico different “genome mining” tools we prospect their genetic potential. The genome size was estimated at 2,272,560 bp and a GC content of 39.26%. Of the total proteins, 2170 matched in the EggNOG database. The key genes related to amino acid biosynthesis, carbohydrate metabolism, exopolysaccharide (EPS) production, were annotated. The genome harbors one intact prophage, one CRISPR array, and two putative gene sequences associated with CAS3 Type I, and no plasmids indicating its stability. Moreover, no acquired resistance genes, virulence and pathogenic factors, nor biogenic amines were predicted, suggesting its safety. In vitro preliminary studies showed that EPS yield from 0.4 to 10.2 (g/L) dry biomass and the production varied with the inoculum size and sugar type MRS containing medium. Furthermore, several polyketides and terpenes were predicted, indicating the possibility of generating a wide range of naturally compounds with broad biological functions. However, these promising results suggest that Ella29 is a beneficial strain to be further exploited in vitro for various technological use.