Inhibitory activity of Lactobacillus plantarum LMG P-26358 against Listeria innocua when used as an adjunct starter in the manufacture of cheese

Abstract

Lactobacillus plantarum LMG P-26358 isolated from a soft French artisanal cheese produces a potent class IIa bacteriocin with 100% homology to plantaricin 423 and bacteriocidal activity against Listeria innocua and Listeria monocytogenes. The bacteriocin was found to be highly stable at temperatures as high as 100°C and pH ranges from 1-10. While this relatively narrow spectrum bacteriocin also exhibited antimicrobial activity against species of enterococci, it did not inhibit dairy starters including lactococci and lactobacilli when tested by well diffusion assay (WDA). In order to test the suitability of Lb. plantarum LMG P-26358 as an anti-listerial adjunct with nisin-producing lactococci, laboratory-scale cheeses were manufactured. Results indicated that combining Lb. plantarum LMG P-26358 (at 108 colony forming units (cfu)/ml) with a nisin producer is an effective strategy to eliminate the biological indicator strain, L. innocua. Moreover, industrial-scale cheeses also demonstrated that Lb. plantarum LMG P-26358 was much more effective than the nisin producer alone for protection against the indicator. MALDI-TOF mass spectrometry confirmed the presence of plantaricin 423 and nisin in the appropriate cheeses over an 18 week ripening period. A spray-dried fermentate of Lb. plantarum LMG P-26358 also demonstrated potent anti-listerial activity in vitro using L. innocua. Overall, the results suggest that Lb. plantarum LMG P-26358 is a suitable adjunct for use with nisin-producing cultures to improve the safety and quality of dairy products.

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

“…plantarum LMG P-26358 in situ. The latter strain was previously shown to have a narrow spectrum of inhibition, inhibiting Listeria and enterococcal strains but not clostridia, Escherichia coli, Bacillus species, Salmonella, or members of the LAB (18). The strain proved to be an effective adjunct for controlling Listeria growth in a cheese model (18).…”

“…The latter strain was previously shown to have a narrow spectrum of inhibition, inhibiting Listeria and enterococcal strains but not clostridia, Escherichia coli, Bacillus species, Salmonella, or members of the LAB (18). The strain proved to be an effective adjunct for controlling Listeria growth in a cheese model (18). In the present study, CSK3594, CSK3281, and CSK3533 failed to inhibit L. innocua by agar well diffusion assay; however, by the end of the ripening period, Listeria numbers from cheeses prepared with these starters were significantly reduced compared to those for the control, vat 1 (no bacteriocin).…”

“…In the case of Lb. plantarum LMG P-26358, the culture was grown in 10% RSM containing 0.1% (vol/vol) yeast extract and 0.2 g/liter MnSO 4 4H 2 O as previously reported (18).…”

“…Nisin (3,352 Ϯ 3 Da), lacticin (Ltn␤) (2,847 Ϯ 4 Da), and plantaricin (3,928 Ϯ 3 Da) present within cheese samples from vats 4, 5, 6, and 7 were verified by MALDI-TOF MS as described previously (18). In the case of lacticin, the presence of the correct mass for Ltn␤ was indicative of lacticin, since Ltn␣ can be difficult to detect in a complex fraction.…”

A novel bacteriocin produced by Lactobacillus plantarum LpU4 as a valuable candidate for biopreservation in artisanal raw milk cheese

“…), IIb (bacteriocins composed of two separate peptides working synergistically to have antimicrobial activity), IIc (cyclic bacteriocins) and IId (single peptide, non-pediocin-like, linear bacteriocins). Several bacteriocins from cheese-isolated Lactobacillus plantarum strains have been characterized in the past (Hernández et al 2005;Mills et al 2011;Martinez et al 2013). Occurrence of non-starter L. plantarum in cheese microbiota appears to be a common trait of a variety of raw milk cheeses (Golic et al 2013;De Pasquale et al 2014;Caro et al 2013).…”