α-.

An α--rhamnosidase producing fungal strain has been isolated from decaying lemon fruit. The fungal strain has been identified as Aspergillus flavus. The α--rhamnosidase has been purified from the culture filtrate of the fungal strain using ultra filtration and cation exchange chromatography on carboxy methyl (CM) cellulose. The molecular mass of the purified enzyme determined by SDS-PAGE analysis was 41 kDa. The K values of the enzyme using p-nitrophenyl-α--rhamnopyranoside and naringin as the substrates were 1.89 and 1.6 m respectively. The pH and temperature optima of the enzyme were 11.0 and 50 °C respectively. The effects of various chemical species present in grape fruit juice and wine on the activity of the enzyme have been determined. [ABSTRACT FROM AUTHOR]