Inhibition of clostridium species responsible for late-blowing defect using different antimicrobial agents

The present study investigated, the effects of different antimicrobial compounds on Clostridium species, responsible for the late-blowing defect (LBD) in the dairy industry. The antimicrobial effect of nisin, lysozyme and water-soluble extracts (WSE) on tested Clostridium spp. strains. The minimum inhibition concentration (MIC) of nisin against vegetative cells of C. sporogenes 73, C. sporogenes 97, and C. butyricum 99 was determined to be 6.25 μg mL-1, 12.5 μg mL-1and 6.25 μg mL-1, respectively. The MIC of nisin against spores of all Clostridium species/strains was found to be 1.56 μg mL-1. However, it was determined that lysozyme, known to be effective on gram-positive microorganisms, and did not affect Clostridium spp. vegetative cells and spores at the 10 mg mL-1 maximum concentration. In addition to nisin and lysozyme, the anticlostridial effect of WSEs from different cheeses was also investigated. The WSEs (50 mg mL-1) obtained from various ripened cheeses did not have an affect on Clostridium spores, whereas they showed a strong antimicrobial effect on vegetative cells. Furthermore, the peptide profiles of these WSEs were determined in reserve-phase high performance liquid chromatography (RP-HPLC), and these peptide profiles were found to differ. (author)