A Multibacteriocin Cheese Starter System, Comprising Nisin and Lacticin 3147 in Lactococcus lactis, in Combination with Plantaricin from Lactobacillus plantarum

Abstract

Functional starter cultures demonstrating superior technological and food safety properties are advantageous to the food fermentation industry. We evaluated the efficacies of single-and double-bacteriocin-producing starters of Lactococcus lactis capable of producing the class I bacteriocins nisin A and/or lacticin 3147 in terms of starter performance. Single producers were generated by mobilizing the conjugative bacteriophage resistance plasmid pMRC01, carrying lacticin genetic determinants, or the conjugative transposon Tn5276, carrying nisin genetic determinants, to the commercial starter L. lactis CSK2775. The effect of bacteriocin coproduction was examined by superimposing pMRC01 into the newly constructed nisin transconjugant. Transconjugants were improved with regard to antimicrobial activity and bacteriophage insensitivity compared to the recipient strain, and the double producer was immune to both bacteriocins. Bacteriocin production in the starter was stable, although the recipient strain proved to be a more efficient acidifier than transconjugant derivatives. Overall, combinations of class I bacteriocins (the double producer or a combination of single producers) proved to be as effective as individual bacteriocins for controlling Listeria innocua growth in laboratory-scale cheeses. However, using the double producer in combination with the class II bacteriocin producer Lactobacillus plantarum or using the lacticin producer with the class II producer proved to be most effective for reducing bacterial load. As emergence of bacteriocin tolerance was reduced 10-fold in the presence of nisin and lacticin, we suggest that the double producer in conjunction with the class II producer could serve as a protective culture providing a food-grade, multihurdle approach to control pathogenic growth in a variety of industrial applications. IMPORTANCEWe generated a suite of single-and double-bacteriocin-producing starter cultures capable of generating the class I bacteriocin lacticin 3147 or nisin or both bacteriocins simultaneously via conjugation. The transconjugants exhibited improved bacteriophage resistance and antimicrobial activity. The single producers proved to be as effective as the double-bacteriocin producer at reducing Listeria numbers in laboratory-scale cheese. However, combining the double producer or the lacticin-producing starter with a class II bacteriocin producer, Lactobacillus plantarum LMG P-26358, proved to be most effective at reducing Listeria numbers and was significantly better than a combination of the three bacteriocin-producing strains, as the double producer is not inhibited by either of the class I bacteriocins. Since the simultaneous use of lacticin and nisin should reduce the emergence of

Dietary Fibers and Protective Lactobacilli Drive Burrata Cheese Microbiome

“…and Enterobacteriaceae) are the main spoiling agents of burrata cheeses (4,9,10). One of the approaches used to prevent the growth of undesirable microorganisms and prolong the shelf life of fresh cheese is the application of biopreservatives (i.e., nisin or protective cultures) (11)(12)(13)(14)(15)(16). Protective cultures are live microorganisms that are deliberately added to food items to inhibit the growth of undesired (spoiling and/or pathogenic) microorganisms, without negatively affecting the sensorial quality of food (11).…”

LAB Bacteriocins Controlling the Food Isolated (Drug-Resistant) Staphylococci

“…Bacteriocins, especially those produced by lactic acid bacteria (LAB), are useful compounds to be applied in food industry. In fact, many of the producer bacteria are regarded as safe (GRAS) or enjoy the status of qualified presumption of safety (QPS), which favors their usage in foods (Cotter et al, 2005 ; Gálvez et al, 2007 ; Lianou et al, 2017 ; Lourenço et al, 2017 ; Mills et al, 2017 ). The main purpose of this study was to assess the potential of bacteriocins and their in vitro synergistic effects in combination against four species of Staphylococcus isolated from a sample of Spanish goat cheeses.…”

“…In fact, the great potential of bacteriocins used in conjunction with or as potential alternatives to antibiotics, is one of the most promising options in the next wave of antibacterial compounds (Cavera et al, 2015 ). Nevertheless, the field where combination of bacteriocins has met more application is the food industry, where they have shown broad potential, a long record of safety and control over undesirable bacteria (Cotter et al, 2005 ; Gálvez et al, 2007 ; Lianou et al, 2017 ; Lourenço et al, 2017 ; Mills et al, 2017 ).…”

Renaissance of traditional DNA transfer strategies for improvement of industrial lactic acid bacteria

“…For example, in L. lactis genes encoding lactose utilization, extracellular proteinase, and polysaccharide production are commonly encoded on conjugal plasmids [20], whereas nisin production as well as sucrose and raffinose utilization are encoded on ICEs [21,22]. Mobilization of these elements allows the combination of beneficial traits in a single strain [23], or alteration of a strain's capacity to interact with its environment [24]. However, MGEs have also been associated with undesirable traits like antibiotic resistance.…”