Biochemical properties of lipase produced from Aspergillus niger isolated from compost soil and its industrial significance

This study investigated the biochemical properties of lipase produced from Aspergillus niger isolated from compost soil and its industrial significance. Soil samples were collected using the soil auger. The medium was compounded using the various salts in grams per litre (g/L) and sugarcane bagasse as a carbon source. The crude extract was subjected to ammonium sulphate fractionation. The precipitate was dissolved with 10 mM sodium phosphate buffer pH 6.5. Gel filtration was done using Sephadex G-200 resin. A column (4.5 x 30 cm) was packed by eluting the same buffer at a flow rate of 5mL/min with test tubes. The physicochemical properties such as pH, temperature, substrate concentration, incubation time, thermal stability and kinetic constants Km and Vmax were determined. Enzyme activity was assayed; the unit activity for lipase was 4.60 U/ml, to 7.20U/ml. The optimum temperature for lipase was at 60°C with an optimum activity at 30 minutes of incubation. The optimum activity for the enzymes was at pH 8. The result shows that Ca2+, Zn2+ and EDTA inhibit the activity of the enzyme while Cu+ activate the activity when compared to the control while EDTA increases the lipase activity whereas Ca2+, Zn2+, and Cu+ suppress it. From the physicochemical properties of the enzyme produced by Aspergillus niger, the findings show that theenzyme possess the properties to withstand industrial processes.