A novel glucoamylase activated by manganese and calcium produced in submerged fermentation by Aspergillus phoenicis

Abstract

This study investigates the production of glucoamylase from Aspergillus phoenicis in Machado Benassi (MB) medium using 1% maltose as carbon source. The maximum amylase activity was observed after four days of cultivation, on static conditions at 30 °C. Glucoamylase production was induced by maltose and inhibited by different glucose concentrations. The optimum of temperature and pH were 60-65 °C, and 4.5 or 5.0 to sodium acetate and Mcllvaine buffers, respectively. It was observed that the enzyme was totally stable at 30-65 °C for 1 h, and the pH range was 3.0-6.0. The enzyme was mainly activated by manganese (176%), and calcium (130%) ions. The products of starch hydrolysis were analyzed by thin layer chromatography and after 3 h, only glucose was detected, characterizing the amylolytic activity as a glucoamylase.

Keywords: Activation; Aspergillus phoenicis; Calcium activation; Glucoamylase; Manganese activation.