Unravelling the Potential of Lactococcus lactis Strains to Be Used in Cheesemaking Production as Biocontrol Agents.

Danka Bukvicki,Margherita D’Alessandro,Francesca Patrignani,Laila Ben Said,Sofia Cosentino,Lorenzo Siroli,Rosalba Lanciotti,Hebatoallah Hassan,Ismail Fliss

doi:10.3390/foods9121815

Abstract

This research, developed within an exchange program between Italy and Canada, represents the first step of a three-year project intended to evaluate the potential of nisin-producing Lactococcus lactis strains isolated from Italian and Canadian dairy products to select a consortium of strains to be used as biocontrol agents in Crescenza and Cheddar cheese production. In this framework, the acidification and the production of nisin in milk, and the volatile molecule profiles of the fermented milk, were recorded. The strains were further tested for their anti-Listeria monocytogenes activity in milk. The data obtained highlighted good potential for some of the tested strains, which showed production of nisin beginning within 12 h after the inoculation and reaching maximum levels between 24 and 48 h. The highest inactivation levels of L. monocytogenes in milk was reached in the presence of the strains 101877/1, LBG2, 9FS16, 11FS16, 3LC39, FBG1P, UL36, UL720, UL35. The strains generated in milk-specific volatile profiles and differences in the presence of fundamental aromatic molecules of dairy products, such as 2-butanone and diacetyl. The results highlight the interesting potential of some L. lactis strains, the producer of nisin, to be further used as biocontrol agents, although the strains need to be tested for interaction with traditional thermophilic starters and tested in real cheesemaking conditions.

Highlights

Cheeses and dairy products are widely consumed, and they represent one of the fastest growing sectors within the food industry [1,2]
Nisin-Encoding order toOfidentify the typeGene of produced nisin for LSGA1B, FBG1P, LBG1G, LSG3, LBG2), a 598-bp fragment was toamplified from genomicnisin of these FBG1P, strains,LBG1G, whichLSG3, was LBG2), identical to that of
The present research, developed by an exchange project between Italy and Canada–Quebec, focused on the characterization of L. lactis strains in terms of their fermentation capabilities in cow milk, ability to generate good volatile profiles, the nisin production, and the ability to inhibit L. monocytogenes when co-inoculated in milk to select a consortium of strains to be further used for biopreservation in cheese production

Summary

Introduction

Cheeses and dairy products are widely consumed, and they represent one of the fastest growing sectors within the food industry [1,2]. The incorporation of nisin-producing L. lactis strains could be a strategy to increase the desirable sensory features of the final dairy products For this purpose, the selection of suitable L. lactis strains needs to take into account some important safety and technological considerations, such as the strain’s antibiotic resistance [20,21], the strain’s ability to quickly ferment the substrate and produce acid (in case it is used as a starter), to impart good sensory properties, and to inhibit the growth of pathogenic microorganisms (especially if used as biocontrol agents) [10,21].

Methods

Results

Discussion

Conclusion