Evaluation of the lipolytic activity of starter cultures for meat fermentation purposes

A modified pork fat based agar method was specially developed to determine the lipolytic activity of starter strains used for meat fermentations. The lipolytic ability of strains of lactobacilli, pediococci, staphylococci and micrococci, was examined on agar plates using different substrates and in a lipid broth model system. The screening results indicate that lipase activity was confined to strains of Staphylococcus and Micrococcus. None of the lactic acid bacteria tested showed lipolytic activity. A strain of Staphylococcus xylosus, which displayed high lipolytic activity during the screening process was examined to find its optimum conditions for lipase activity regarding pH, temperature and NaCl concentration. The lipolytic activity of seven bacterial strains was determined under optimum conditions (0% salt, pH 7 and 30°C) and sausage conditions (3.5% salt, pH 5 and 20°C) using fat buffer model systems. High lipolytic activity was determined for all seven strains under optimal conditions, whereas no activity was detected under fermented sausage conditions.