Lipase enzyme production with lactic acid bacteria

Fifty lactic acid bacteria isolated from milk and cheese were screened for lipase activity. Eleven isolates with high lipase activity were selected. Those selected 11 isolates were identified by 16S rRNA sequence analysis. Nine of 11 isolates were identified as E. faecium and 2 as E. durans. Optimum enzyme production conditions were determined with those selected isolates. Optimum growth conditions for lipase production were determined with selected bacteria. The activity of the extracellular enzymes was maximum that obtained from microorganisms after incubation at 40-60° C, 48 hour and 120 rpm in a medium containing 5% peptone as nitrogen source and pH 6.5 as carbon source. Factors affecting extracellular enzyme activity that was produced under optimum conditions were determined. The partially purified extracellular enzyme activity was maximum at 30-45°C and pH 9-10. Lipase enzymes showed halophilic properties, high activity was observed at high salt concentrations. The resistance of the extracellular enzymes against temperature was changed according to the strains. The activity of extracellular enzymes was continued after incubation in 45oC alkaline medium (pH 8-11) for 3.5 hours. The effect of various cations and surfactants on enzyme activity showed differences. Olive waste may also be a suitable medium for lipase production. However, further studies are needed. Partially purified extracellular enzymes of Enterococcus spp. strains were active in low temperature and high temperature and had halophilic properties. Because of those properties, they will be used in the food industry, especially in the fermented products such as meat and dairy products for the purpose of providing flavor, in the future. Keywords: Enterococcus faecium, Enterococcus durans, Lipase, Enzyme activity