Production of Extracellular Phospholipase C by Species of Genus Bacillus with Potential for Bioremediation

The application of phospholipases produced by species of genus Bacillus in different industries reduces the negative impact on the environment by reducing the need of toxic chemicals, consumed energy, and produced carbon emissions. In the current study one hundred sixty-six bacterial strains belonging to the genus Bacillus were tested for phospholipase C production. Eighty-seven percent of the studied strains demonstrated phospholipase C activity on egg-yolk agar. Strain Bacillus thuringiensis was selected as the most promising for the phospholipase production with initial activity of 19.61 U/ml. The nutrient medium composition and cultivating conditions were optimized for achieving higher enzyme yields. The highest phospholipase production was achieved on the following conditions of the liquid medium: 1% of yeast extract as a source of nitrogen; 0.5% NaCl; 0.4% of glucose as a carbon source; NaHCO3 – 3 g/l; Na2HPO4 – 0.4 g/l; 1 mM ZnCl2; pH 7; inoculated with 3% (1.4 x 109 cfu/ml) subculture and 8 hours duration of the cultivation. The production of phospholipase C by the selected strain was scaled up in a bioreactor with a volume of 2l.