Purification and functional properties of a novel glucoamylase activated by manganese and lead produced by Aspergillus japonicus

Author(s)

Pasin, Thiago Machado ; Benassi, Vivian Machado ; Heinen, Paulo Ricardo ; de Lima Damasio, Andre Ricardo ; Cereia, Mariana ; Jorge, Joao Atilio ; Teixeira de Moraes Polizeli, Maria de Lourdes

• Document type: Journal article
• Source: International Journal of Biological Macromolecules; v. 102, p. 779-788, SEP 2017.
• Web of Science Citations: 9

Abstract

Microbial amylases are used to produce ethanol, glucose and can be applied in textiles products, detergents and other industries. This study aimed to determine the best carbon source concentration to induce the amylase production by A. japonicus, and its purification and biochemical characterization. For that, this fungus was cultivated in Khanna medium, pH 5.5, for 4 days, at 25 degrees C, in static condition, supplemented with potato starch and maltose in different concentrations. The fungal crude enzymatic extract was purified in a unique elution in DEAE-cellulose column and the molecular mass was determined as 72 kDa. The optimum temperature and pH was 65 degrees C and 5.0, respectively. Amylase remained 75% of its activity after one hour at 50 degrees C and was stable in the pH range 3.0-7.0. The analysis of the end-products by thin layer chromatography showed only glucose formation, which characterizes the purified enzyme as a glucoamylase. Amylopectin was the best substrate for the enzyme assay and Mn+2 and Pb+2 were good glucoamylase activators. This activation, in addition to the biochemical characteristics are important results for future biotechnological applications of this glucoamylase in the recycling and deinking process by the paper industries. (C) 2017 Elsevier B.V. All rights reserved. (AU)