Biochemical characterization of three phase partitioned naringinase from Aspergillus brasiliensis MTCC 1344

Naringinase is a complex enzyme composed of alpha-L-rhamnosidase and beta-D-glucosidase, which has a vast potential application in the field of industrial biotechnology. The novel aspect in the present study is employing a three-phase partitioning (TPP) technique for the purification of naringinase by solid-state fermentation using Aspergillus brasiliensis MTCC 1344. At optimum conditions of 28 +/- 2 degrees C and 30% (w/v) ammonium sulfate along with a 1:1 ratio of t-butanol to crude extract, the purification is enhanced by 4.2-fold. Temperature and pH profile of TPP purified naringinase was found to be active with an optimal activity of 719.6 units at an elevated temperature of 60 degrees C. The kinetic constants K-m and V-max using naringin as substrate were 3.21 mM and 321 U/ml. The purified enzyme was not inhibited by any metal ions except Hg2+ but completely inhibited by adding chelating agents such as EDTA and SDS at a concentration of 10 mM. These results can be inevitable to establish the TPP method to be an inexpensive, economical and attractive technology for better recovery and to find its application in the industrial sector. (C) 2015 Elsevier B.V. All rights reserved.