Bacteriocin-producing (Bac+) lactic acid bacteria (LAB) were isolated from a variety of food products and animal sources. Samples were enriched in de Man, Rogosa, and Sharpe (MRS) Lactocilli broth and plated onto MRS agar plates using a “sandwich overlay” technique. Inhibitory activity was detected by the “deferred antagonism” indicator overlay method using Listeria monocytogenes as the primary indicator organism. Antimicrobial activity against L. monocytogenes was detected by 41 isolates obtained from 23 of 170 food samples (14%) and 11 of 110 samples from animal sources (10%) tested. Isolated Bac+ LAB included Lactococcus lactis, Lactobacillus curvatus, Carnobacterium maltaromaticum, Leuconostoc mesenteroides, and Pediococcus acidilactici, as well as Enterococcus faecium, Enterococcus faecalis, Enterococcus hirae, and Enterococcus thailandicus. In addition to these, two Gram-negative bacteria were isolated (Serratia plymuthica, and Serratia ficaria) that demonstrated inhibitory activity against L. monocytogenes, Staphylococcus aureus, and Enterococcus faecalis (S. ficaria additionally showed activity against Salmonella Typhimurium). These data continue to demonstrate that despite more than a decade of antimicrobial interventions on meats and produce, a wide variety of food products still contain Bac+ microbiota that are likely eaten by consumers and may have application as natural food preservatives.
|Number of pages||14|
|State||Published - Mar 2015|
Bibliographical noteFunding Information:
This paper was funded in part by an OCAST-OARS grant (#AR12-049), Nutrition Physiology Co. (Guyman, OK, USA), the Department of Animal Science, the R.M. Kerr Food & Ag Products Center (Oklahoma State University), and the Oklahoma Agricultural Experiment Station (Hatch Project #OKL02885).
© 2015 by the authors; licensee MDPI, Basel, Switzerland.
- Food preservative
- Lactic acid bacteria
- Listeria monocytogenes
ASJC Scopus subject areas
- Microbiology (medical)