Purification and characterization of an amyloglucosidase from an ericoid mycorrhizal fungus (Leohumicola incrustata).

ABSTRACT: This study aimed to purify and characterize amyloglucosidase (AMG) from Leohumicola incrustata. AMG was purified to homogeneity from cell-free culture filtrate of an ERM fungus grown in a modified Melin-Norkrans liquid medium. The molecular mass of the AMG was estimated to be 101 kDa by combining the results of Sephadex G-100 gel filtration, sodium dodecyl sulphate-polyacrylamide gel electrophoresis, and zymography. The Km and kcat values were 0.38 mg mL-1 and 70 s-1, respectively, using soluble starch as a substrate. The enzyme was stable at 45 °C (pH 5.0), retaining over 65% activity after a pre-incubation period of 24 h. The metal inhibition profile of the AMG showed that Mn2+ and Ca2+ enhanced activity, while it was stable to metals ions, except a few (Al3+, Co2+, Hg2+ and Cd2+) that were inhibitory at a concentration higher than 5 mM. Thin layer chromatography revealed that only glucose was produced as the product of starch hydrolysis. The amylase from L. incrustata is a glucoamylase with promising characteristics such as temperature stability over an extended period, high substrate affinity and stability to a range of chemicals. Also, this study reports for the first time the possibility of using some culturable ERM fungi to produce enzymes for the bio-economy.

SUBMITTER: Adeoyo OR 

PROVIDER: S-EPMC6163121 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature