Screening of lactic acid bacteria from vacuum packaged beef for antimicrobial activity

Abstract

The objective of this study was to isolate lactic acid bacteria (LAB) from vacuum packaged beef and to investigate their antagonist activity. LAB mean counts of 5.19 log cfu/cm 2 were obtained from five samples of vacuum packaged beef. Two hundred isolates were selected and screened for the inhibitory effect on five ATCC reference Lactobacillus strains. Thirty six isolates showed activity in the agar spot test against at least two of the indicator strains. However, only six cell free supernatants (CFS) from these isolates exhibited activity against the indicator strains using the well-diffusion test and conditions that eliminated the effects of organic acids and hydrogen peroxide. L. acidophilus was the most sensitive indicator tested, whereas L. plantarum and L. fermentum were the most resistant ones. Identification by MIDI system indicated that these LAB isolates were Lactococcus lactis subsp. cremoris, Pediococcus acidilactici, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus casei GC subgroup A. The antagonistic factors produced by most of these LAB against L. acidophilus were resistant to heat treatment (100ºC for 10 min) and stable over a wide pH range (4.0 to 9.0). These data suggest that these isolates could be used as promising hurdles aiming increased safety and extended shelf life of meat products.

Evaluation on Antibacterial Activity of <i>Lactobacillus acidophilus</i> Strains Isolated from Honey

“…Similarly, Coconnier et al (1997) observed that the antimicrobial activity of supernatant of L. acidophilus strain LB from human was heat stable at 110 ο C for 1 and the activity was increased under acidic condition against S. Typhimurium, E. coli, Listeria monocytogenes, Shigella flexneri, Klebsiella pneumoniae, Pseudomonas aeruginosa and Enterobacter spp. Ollveira et al (2008) reported that L. acidophilus 30SC produced antimicrobial compound that was heat stable at 95°C for 20 minand 50% of activity was lost after heating at 121°C for 20 min Heating supernatant of L casei GC subgroup A isolated from vacuum packaged beef at 100 ο C for 10 min showed antagonistic activity against reference strains L. acidophilus, L. fermentum and L. plantarum (Oh et al, 2000). The antibacterial activity of strains of L. acidophilus 1 supernatants was active under acidic conditions between pH 3-5 against all target Gram negative bacteria (Table 7 and 8).…”

“…Maurad and Meriem (2008) reported that the antimicrobial activity of L. plantarum isolated from camel milk butter was stable at pH 2-6 but the activity was lost at pH 8 against indicator strain of Lactococcus lactis B8. Ollveira et al (2008) isolated Lactobacillus casei GC subgroup A from vacuum packaged beef and had antagonistic activity against indicator strains of L. acidophilus, L. fermentum and L. plantarum; the activity was stable at pH 4-9.…”

Inhibition of mycotoxin-producing Aspergillus nomius vsc 23 by lactic acid bacteria and Saccharomyces cerevisiae

“…Lactic acid bacteria (LAB) are GRAS (generally recognized as safe) microorganisms that modify the food enhancing quality, and additionally they possess nutritional and therapeutic benefits (20). The majority of the numerous reports on antimicrobial activity by LAB have focused on antibacterial effects (30), whereas there are only few reports on antifungal effects. The adaptability of LAB and yeasts to sourdoughs prepared from cereals, was investigated, the dominant LAB was Lactobacillus fermentum and S. cerevisiae constituted the dominating yeast (40).…”

Synergistic growth effect among bacteria recovered from root canal infections

“…Gram-negative bacteria (17). In this study, L. paracasei presented antagonistic activity against S. anginosus and G.…”