Adventitious dairy Leuconostoc strains with interesting technological and biological properties useful for adjunct starters

CARDAMONE, LUISINA; QUIBERONI, ANDREA; MERCANTI, D.J.; FORNASARI, M.E. ; REINHEIMER, JORGE A.; GUGLIELMOTTI, DANIELA M.

DAIRY SCIENCE & TECHNOLOGY

EDP SCIENCES S A

Lugar: Rennes Cedex; Año: 2011 p. 457 - 470

1958-5586

Some species of Leuconostoc are very important for fermented dairy products, as they contribute to the organoleptic characteristics of butter and cream, and also contribute to the formation of openings in some soft, semi-hard (Edam and Gouda cheeses), many artisanal or in blue-veined cheeses, such as Roquefort. In this study, 14 Leuconostoc strains isolated from cheese and cheese-related products were characterized by genotypic and phenotypic methods, and their technological performance assessed for their potential use as dairy adjunct starters. Phenotypic characterization allowed these strains to be classified to genus level, and genotypic studies (RAPD-PCR and 16S rRNA gene sequencing) identified them to species/ subspecies level. Five Leuconostoc strains grew well and acidified milk, and most of them grew even at 8 °C. They showed moderate resistance to heat treatments (30 min at 63 °C) and grew well in the presence of 3% and 4% NaCl, and were significantly inhibited at pH ≤5. All strains showed resistance against the bacteriophages tested. In general, the antibacterial properties observed were slight and due to acid production, with the exception of Leuconostoc citreum MB1, which strongly inhibited Listeria monocytogenes ATCC 15313 by the production of a bacteriocin-like compound. All Leuconostoc strains studied were susceptible to gentamicin, tetracycline, erythromycin and ampicillin. Some strains also showed interesting technological and antimicrobial properties, thus being potentially appropriate as adjunct starters in fermented dairy products. This study highlights that adventitious lactic acid bacteria can be a great source of novel strains with interesting technological features that could be used for fermented dairy foods.