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Saraoui, Taous; Fall, Papa-abdoulaye; Leroi, Francoise; Antignac, Jean-philippe; Chereau, Sylvain; Pilet, Marie France. |
Listeria monocytogenes is a pathogenic Gram positive bacterium and the etiologic agent of listeriosis, a severe food-borne disease. Lactococcus piscium CNCM I-4031 has the capacity to prevent the growth of L. monocytogenes in contaminated peeled and cooked shrimp. To investigate the inhibititory mechanism, a chemically defined medium (MSMA) based on shrimp composition and reproducing the inhibition observed in shrimp was developed. In co-culture at 26°C, L. monocytogenes was reduced by 3-4 log CFU g-1 after 24 h. We have demonstrated that the inhibition was not due to secretion of extracellular antimicrobial compounds as bacteriocins, organic acids and hydrogen peroxide. Global metabolomic fingerprints of these strains in pure culture were assessed by... |
Tipo: Text |
Palavras-chave: Listeria monocytogenes; Lactococcus piscium; Nutrients competition; Cellular contact; Chemically defined medium; Bacterial interaction. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00250/36123/34677.pdf |
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Fall, Papa-abdoulaye; Pilet, Marie-france; Leduc, Francois; Cardinal, Mireille; Duflos, Guillaume; Guerin, Camille; Joffraud, Jean-jacques; Leroi, Francoise. |
This study investigated the sensory quality and physicochemical evolution (pH, glucose, l-lactic acid, biogenic amine, free amino-acids and volatile compounds) during storage at 8 °C of cooked peeled shrimp inoculated with the specific spoilage bacteria Brochothrix thermosphacta alone or mixed with the protective strain Lactococcus piscium CNCM I-4031. Growth of both bacteria was monitored at regular intervals during storage by microbial counts and the thermal temperature gradient gel electrophoresis (TTGE) technique. Bacterial counts showed that L. piscium and B. thermosphacta inoculated at 7 log CFU/g and 3 log CFU/g were well adapted to shrimp, reaching a maximum level of 9 log CFU/g after 4 days and 10 days respectively. In mixed culture, the growth of... |
Tipo: Text |
Palavras-chave: Biopreservation; Sensory quality; Volatile compounds; Biogenic amines; Amino-acid; TTGE. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00042/15348/15630.pdf |
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Leroi, Francoise; Fall, Papa-abdoulaye; Pilet, Marie-france; Chevalier, Frederique; Baron, Regis. |
The maximum specific growth rate (μmax) of Brochothrix thermosphacta, a spoilage bacteria of cooked peeled shrimp, and Lactococcus piscium CNCM I-4031, a bioprotective strain, was investigated under different conditions of temperature, NaCl concentrations and pH. The basic modelling approach used was the Gamma concept (γ-concept) and the model developed was then adapted to shrimp. Cardinal growth parameters were quite similar for the two strains, except for NaCl. No NaCl was required for growth and the NaClmax was three-times higher for B. thermosphacta than for L. piscium (62 and 23 g l−1 respectively). However, tolerance to NaCl was higher in seafood than in liquid broth, possibly due to presence of osmoltically active molecules. L. piscium and B.... |
Tipo: Text |
Palavras-chave: Modelling; Biopreservation; Shrimp; Lactic acid bacteria; Brochothrix thermosphacta; Spoilage bacteria; Environmental conditions. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00083/19473/17088.pdf |
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