In vitro and in situ screening of lactic acid bacteria and propionibacteria antifungal activities against bakery product spoilage molds

Published Date
February 2016, Vol.60:247–255, doi:10.1016/j.foodcont.2015.07.034

Author 

• Céline Le Lay
• Jérôme Mounier
• Valérie Vasseur
• Amélie Weill
• Gwenaëlle Le Blay ¹
• Georges Barbier
• Emmanuel Coton ^,

• Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France

Received 3 April 2015. Revised 20 July 2015. Accepted 25 July 2015. Available online 28 July 2015. 

Highlights

• Biodiversity and resistance to preservatives of bakery product fungal contaminants.
• •
  Aspergillus and Eurotium species were the most dominant and resistant.
• •
  Combination of in vitro and in situ approaches for antifungal bacteria identification.
• •
  Selection of isolates for use as bioprotective cultures in bakery products.

Abstract

In the agri-food context, bioprotective cultures represent an interesting alternative to chemical preservatives. The aim of this study was to evaluate the in vitro and in situantifungal activity of lactic acid bacteria (LAB) and propionibacteria against bakery product spoilage fungi. Firstly, the biodiversity of fungal contaminant in pound cakes and milk bread rolls, as well as the resistance to chemical preservatives of representative isolates (n = 21), were studied. Aspergillus and Eurotium species were the most dominant spoilage fungi and the most resistant towards the tested chemical preservatives. They were followed by Penicillium, Cladosporium and Wallemia spp. Secondly, an in vitro screening showed that the most active isolates against selected fungal targets belonged to the Leuconostoc spp., Lactobacillus reuteri and Lactobacillus buchneri groups among the 270 tested LAB, as well as to the Propionibacterium freudenreichi and Propionibacterium acidipropionici species for the 50 tested propionibacteria. Finally, in situ tests showed that cultures of isolates belonging to the Leuconostoc citreum, Lactobacillus sakei, Lactobacillus plantarum, Lactobacillus spicheri, L. reuteri and Lactobacillus brevis species could delay one or several target fungal growths after bakery product surface spraying. Moreover, different strain cultures led to delayed fungal growths after incorporation in milk bread rolls preparation. The combination of in vitro and in situ approaches allowed for the identification of bacteria exhibiting antifungal activity, providing future prospects for use as bioprotective cultures in bakery products.

Keywords

Antifungal activity

Bacteria

Molds

Bakery products

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  Corresponding author. Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Parvis Blaise-Pascal, Technopôle Brest-Iroise, 29280 Plouzané, France.

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