Abstract
The current work aimed to study the effect of some component changes of Aspergillus niger culture media on the production of lipase enzyme. Media contained nitrogenous sources, ammonium nitrate, peptone, nitrate phosphate, mono-potassium phosphate, and aqueous magnesium sulfate. It was found that the isolation was unable to grow and produce lipase enzyme efficiently due to the presence of inorganic nitrogen sources. The highest value of the dry weight rate was realized while using ammonium chloride at concentration of 1.23 g/100 ml. Ammonium nitrate was the best source (treatment) compared to the rest of the sources at a concentration of 0.1 g/100 ml, where the dry weight was 1.28 g/100 ml, and the effectiveness of lipase was 22.86 U/ml. Adding peptone with the ammonium nitrate to the medium helped to raise the productivity of isolated fungus, where the dry weight reached 2.75 g/100 ml, while the lipase activity reached 36.93 U/ml. The biomass in the organic nitrogen sources medium reached (2.24 g/100 ml). The highest value of the dry weight of phosphate source media (KH2PO4) reached (2.87 g/100 ml) at a concentration (0.28 g/100 ml), achieving the best value of the lipase's effectiveness (39.96 U/ml). Aqueous magnesium sulfate concentration media resulted in a sort increase in the fungus isolation biomass, as the highest biomass for aqueous magnesium sulfate media was (3.00 g/100 ml) at (0.05 g/100 ml) concentration.