title: Lyophilized preparations of bacteriocinogenic Lactobacillus curvatus and Lactococcus lactis subsp. lactis as potential protective adjuncts to control Listeria monocytogenes in dry-fermented sausages.
abstract: OBJECTIVE
  Study of the effectiveness of in situ bacteriocin production by lactic acid bacteria (LAB) to control Listeria monocytogenes in dry-fermented sausages.
  
  
  RESULTS
  Two bacteriocin-producing strains: Lactococcus lactis subsp. lactis LMG21206 and Lactobacillus curvatus LBPE were grown in a pilot scale fermentor and lyophilized to be directly used in dry sausage fermentation. A commercial starter culture (Bel'meat SL-25) not inhibitory to L. monocytogenes (Bac- starter) was mixed (1 : 1) with each of the two lyophilized bacteriocin-producing strains to obtain starters active against the pathogen (Bac+ starter). Anti-Listeria effectiveness of the Bac+ starters was studied in dry-fermented sausages. The meat batter was experimentally contaminated with a mixture of four different strains of L. monocytogenes (10(2)-10(3) CFU g(-1)). The results showed that L. monocytogenes did not grow in any of the contaminated batches, but no significant decrease (P > 0.05) was observed either in the positive control (no added starter culture) or in samples fermented with the Bac- starter culture during the fermentation period and up to 15 days of drying. When the Bac+ starter contained Lb. curvatus LBPE, cell counts of L. monocytogenes decreased to below the detectable limit (<10 CFU g(-1)) after 4 h of fermentation and no survivors could be recovered by enrichment beyond day 8 of drying. When the Bac+ starter culture containing Lc. lactis LMG21206 was used, a decrease in Listeria counts to below the detectable limit was achieved after 15 days of drying.
  
  
  CONCLUSIONS
  The bacteriocin-producing strains studied may be used as adjunct cultures for sausage fermentations to control the occurrence and survival of L. monocytogenes.
  
  
  CONCLUSIONS
  Addition of the Bac+ strains, especially the Lb. curvatus strain would provide an additional hurdle to enhance the control of L. monocytogenes in fermented meat products.
authors.affiliation: Département des Sciences Alimentaires et Nutritionnelles, Institut Agronomique et Veterinaire Hasssan II, Rabat, Morocco. n.benkerroum@iav.ac.ma
authors.forename: N
authors.initials: N
authors.lastname: Benkerroum
authors.forename: A
authors.initials: A
authors.lastname: Daoudi
authors.forename: T
authors.initials: T
authors.lastname: Hamraoui
authors.forename: H
authors.initials: H
authors.lastname: Ghalfi
authors.forename: C
authors.initials: C
authors.lastname: Thiry
authors.forename: M
authors.initials: M
authors.lastname: Duroy
authors.forename: P
authors.initials: P
authors.lastname: Evrart
authors.forename: D
authors.initials: D
authors.lastname: Roblain
authors.forename: P
authors.initials: P
authors.lastname: Thonart
mesh_terms: D001430:Bacteriocins / Q000096:biosynthesis; D005285:Fermentation; D005516:Food Microbiology; D005519:Food Preservation; D007778:Lactobacillus / Q000378:metabolism; D013294:Lactococcus lactis / Q000378:metabolism; D008461:Meat Products
chemical_list: D001430:Bacteriocins