The two faces of leuconostoc mesenteroides in food systems

Leuconostoc mesenteroides is a lactic acid bacterium (LAB) that has been isolated from different sources. Some of its strains are able to produce bacteriocins, and most of them belong to class IIa and shows anti-Listeria activity. Additionally, Lc. mesenteroides species can be a probiotic candidate; promising studies have shown the potential of this species to survive and grow under various stress conditions present in the gastrointestinal tract. On the other hand, this microorganism can cause spoilage in some types of food matrices, and scarce reports have shown the pathogenic potential of this species. In this review, we focus on an overview of Lc. mesenteroides bacteriocin-producing strains and their probiotic potential, in contrast with Lc. mesenteroides spoilage and pathogenic cases reported in the literature.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Probiotic properties of lactic acid bacteria isolated from water-buffalo mozzarella cheese

This study evaluated the probiotic properties (stability at different pH values and bile salt concentration, auto-aggregation and co-aggregation, survival in the presence of antibiotics and commercial drugs, study of β-galactosidase production, evaluation of the presence of genes encoding MapA and Mub adhesion proteins and EF-Tu elongation factor, and the presence of genes encoding virulence factor) of four LAB strains (Lactobacillus casei SJRP35, Leuconostoc citreum SJRP44, Lactobacillus delbrueckii subsp. bulgaricus SJRP57 and Leuconostoc mesenteroides subsp. mesenteroides SJRP58) which produced antimicrobial substances (antimicrobial peptides). The strains survived the simulated GIT modeled in MRS broth, whole and skim milk. In addition, auto-aggregation and the cell surface hydrophobicity of all strains were high, and various degrees of co-aggregation were observed with indicator strains. All strains presented low resistance to several antibiotics and survived in the presence of commercial drugs. Only the strain SJRP44 did not produce the β-galactosidase enzyme. Moreover, the strain SJRP57 did not show the presence of any genes encoding virulence factors; however, the strain SJRP35 presented vancomycin resistance and adhesion of collagen genes, the strain SJRP44 harbored the ornithine decarboxylase gene and the strain SJRP58 generated positive results for aggregation substance and histidine decarboxylase genes. In conclusion, the strain SJRP57 was considered the best candidate as probiotic cultures for further in vivo studies and functional food products development.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP