Abstract

Naringin was extracted from lemon peels with a yield of 0.25%. The activity of crude naringinase was 157.7μmol/min and 493.64μmol/ min using naringin disappearance and reducing sugars appearance assay methods respectively. Naringinase was precipitated at 50% ammonium sulphate saturation. After gel filtration, a purification fold of 32.84 with specific activity of 7279.37μmol/min/mg was observed while using naringin disappearance assay method and a 20.48 purification fold with specific activity of 14463.57μmol/min/mg with reducing sugars appearance method of assay. Percentage yields of 11.63% and 7.38% were observed using naringin disappearance and reducing sugars appearance methods of assay respectively. The enzyme pH and temperature optima were found to be 3.50 and 50 °C with a Km and V_max obtained as 5.8mg/ml and 1111.11μmol/ min respectively. This investigation suggests that lemon peels could be a good source of naringin which could be used as a carbon source in submerged fermentation for naringinase production using Aspergillus niger.

Keywords: Naringin; Naringinase; Aspergillus niger; Submerged fermentation and lemon peels