A finished compost sample was examined for bacteriocin-like substance production against five pathogenic bacteria: Salmonella typhimurium EF 85-9, Escherichia coli O157:H7 ATCC 43888, Enterococcus faecalis JCM 8726, Staphylococcus aureus JCM 2151, and Yersinia enterocolitica JCM 7577. At the preliminary detection of bacterial stains exhibiting antimicrobial activity from the compost sample, thirteen strains could be isolated. Screening of the inhibitory activity was done using agar-well diffusion assay and Microtiter plate growth assay. Six bacterial strains from the compost showed an antimicrobial activity against one or more of the tested indicator strains. Four strains (M1-M4) belonged to Shigella species and the other two strains (M5 and M6) be-longed to Salmonella species. The antimicrobial activity was sensitive for α-chymotrypsin and papain. The antimicrobial substances from M3, M4 and M6 were heat stable when heated for 15 min at 121°C with 100% relative activity. The bacteriocin-like substance produced by strain M2 was partially characterized. It exhibited an inhibitory activity against the tested food-borne patho-genic and spoilage bacteria, except Enterobacter aerogenes JCM 1235 and Lactobacillus plan-tarum subsp. plantarum JCM 1149. It was stable at a wide range of pH (3-11). There was no loss of activity for up to 3 weeks when stored at 4 and -20°C or for up to 2 weeks when stored at 28 and -80°C. This is the first report indicating the presence of bacteriocin-like activity in animal manure compost.
- Salmonella sp
- Shigella sp