New insights into the antifungal activity of lactic acid bacteria isolated from different food matrices

F Panebianco,A Caridi

doi:10.3989/gya.1262192

Abstract

The anti-mold activity of 397 strains of lactic acid bacteria was evaluated using both the spot method in Petri plates and coculture in liquid medium. The study led to the selection of 34 strains isolated from table olives or olive brines, 15 strains from dairy products, and 10 strains from sourdoughs, all able to inhibit a strain of Penicillium crustosum and/or a strain of Aspergillus section Nidulantes, prevailing in two Calabrian olive brines. Seven representative strains were identified as Lactobacillus pentosus (four strains) and Lactobacillus sanfranciscensis (three strains) and are currently under testing for their antifungal activity during table olive fermentation. This research constitutes an initial contribution to the control of fungal growth and mycotoxin accumulation during table olive fermentation. The selected strains could be used as adjunct cultures in table olive fermentation, allowing for the biological control of table olive safety.

Highlights

In Mediterranean countries, table olives are among the most commonly consumed fermented food
All the lactic acid bacteria (LAB) strains were able to inhibit the growth of Penicillium crustosum at the spore suspension 1:100; strains (98.3% of all LAB) inhibited the growth of Aspergillus section Nidulantes at the same concentration
This study makes a useful contribution to solving the problem of fungal growth and potential mycotoxin accumulation during table olive fermentation, thereby improving its safety

Summary

Introduction

In Mediterranean countries, table olives are among the most commonly consumed fermented food. They are considered a functional food due to their nutritional value, content in bioactive compounds and dietary fiber, fatty acid composition and presence of several antioxidants (Campus et al, 2018). They can produce mycotoxins and cause the softening of fruits because of their cellulase and xylanase activities (Arroyo-López et al, 2016). Penicillium crustosum is one of the most prevalent molds in fermented black table olives and is able to produce toxic metabolites such as dehydrocyclopeptin, andrastin A, cyclopenol, penitrem A, roquefortine C, viridicatol (Bavaro et al, 2017) and thomitrem A and E (Rundberget and Wilkins, 2002)

Objectives

Methods

Results

Discussion

Conclusion