Journal article
Growth inhibition of Listeria monocytogenes by a nonbacteriocinogenic Carnobacterium piscicola
Aims: This study elucidates the mechanisms by which a nonbacteriocinogenic Carnobacterium piscicola inhibits growth of Listeria monocytogenes. Methods and Results: Listeria monocytogenes was exposed to live cultures of a bacteriocin-negative variant of C. piscicola A9b in co-culture, in a diffusion chamber system, and to a cell-free supernatant.
Suppression of maximum cell density (0-3.5 log units) of L. monocytogenes was proportional to initial levels of C. pisciola (10(3)-10(7) CFU ml(-1)). Cell-to-cell contact was not required to cause inhibition. The cell-free C. piscicola supernatant caused a decrease in L. monocytogenes maximum cell density, which was abolished by glucose addition but not by amino acid, vitamin or mineral addition.
The fermentate also gave rise to a longer lag phase and a reduction in growth rate. These effects were independent of glucose and may have been caused by acetate production by C. piscicola. 2D gel-electrophoretic patterns of L. monocytogenes exposed to C. piscicola or to L. monocytogenes fermentate did not differ.
Treatment with C. piscicola fermentate resulted in down-regulation (twofold) of genes involved in purine- or pyrimidine metabolism, and up-regulation (twofold) of genes from the regulon for vitamin B-12 biosynthesis and propanediol and ethanolamine utilization. Conclusions: A nonbacteriocinogenic C. piscicola reduced growth of L. monocytogenes partly by glucose depletion.
Significance and Impact of the Study: Understanding the mechanism of microbial interaction enhances prediction of growth in mixed communities as well as use of bioprotective principles for food preservation.
Language: | English |
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Year: | 2005 |
Pages: | 172-183 |
ISSN: | 13652672 , 13645072 , 1472765x and 02668254 |
Types: | Journal article |
DOI: | 10.1111/j.1365-2672.2004.02438.x |
ORCIDs: | Gram, Lone and 0000-0003-3777-7123 |