Antifungal and antimycotoxigenic effect of Lactobacillus plantarum CRL 778 at different water activity values

DALLAGNOL, AM; BUSTOS, AY; MARTOS, G; FONT DE VALDEZ, G; GEREZ, CL

REVISTA ARGENTINA DE MICROBIOLOGíA

ASOCIACION ARGENTINA MICROBIOLOGIA

Lugar: Buenos Aires; Año: 2019 p. 164 - 169

0325-7541

Ochratoxin A (OTA) is a mycotoxin produced by filamentous fungi with high impact in food safety due to its toxic properties. In the last decade, the OTA presence has been extensively reported worldwide in diverse food. In this study, the ability of Lactobacillus (L.) plantarum CRL 778 to control the growth and the OTA production by Aspergillus (A.) niger 13D strain, at different water activity (aw) values (0.955, 0.964, 0.971, 0.982, and 0.995) in in vitro assays was determined. Both parameters were significantly (p < 0.05) reduced by the lactobacilli, being the effect dependent on the aw. The greatest growth rate inhibition (46.9%) was obtained at 0.995 aw, which is the most suitable value for the growth and production of antifungal metabolites (lactic acid, acetic acid, phenyllactic and hydroxyl-phenyllactic acids) by CRL 778 strain. Besides, morphological changes and inhibition of melanin synthesis were observed in colonies of A. niger 13D growing in presence of L. plantarum CRL 778 at 0.971-0.995 aw. In addition, the maximum percentage of reduction (90%) of OTA production took place at 0.971 aw, while the inhibition of fungi growth was more evident at 0.995 aw. These findings suggest that L. plantarum CRL 778 could be used for the control of ochratoxigenic fungal and OTA contamination in different food with 0.971-0995 aw values.