Genetic Diversity of Leuconostoc mesenteroides Isolates from Traditional Montenegrin Brine Cheese

Abstract

In many dairy products, <i>Leuconostoc</i> spp. is a natural part of non-starter lactic acid bacteria (NSLAB) accounting for flavor development. However, data on the genomic diversity of <i>Leuconostoc</i> spp. isolates obtained from cheese are still scarce. The focus of this study was the genomic characterization of <i>Leuconostoc</i> spp. obtained from different traditional Montenegrin brine cheeses with the aim to explore their diversity and provide genetic information as a basis for the selection of strains for future cheese production. In 2019, sixteen <i>Leuconostoc</i> spp. isolates were obtained from white brine cheeses from nine different producers located in three municipalities in the northern region of Montenegro. All isolates were identified as <i>Ln.</i>&nbsp;<i>mesenteroides.</i> Classical multilocus sequence tying (MLST) and core genome (cg) MLST revealed a high diversity of the Montenegrin <i>Ln. mesenteroides</i> cheese isolates. All isolates carried genes of the bacteriocin biosynthetic gene clusters, eight out of 16 strains carried the <i>cit</i>CDEFG operon, 14 carried <i>butA,</i> and all 16 isolates carried <i>alsS</i> and <i>ilv</i>, genes involved in forming important aromas and flavor compounds. Safety evaluation indicated that isolates carried no pathogenic factors and no virulence factors. In conclusion, <i>Ln. mesenteroides</i> isolates from Montenegrin traditional cheeses displayed a high genetic diversity and were unrelated to strains deposited in GenBank.