Phenotypic and molecular characterization of Aspergillus species for the production of starch-saccharifying amyloglucosidase

The continuous exploration of new microbial cell factories in diverse environmental and geographical locations has led to pivotal developments in the production of industrially important extracellular metabolites. Filamentous fungi are used for large-scale production of various enzymes, and amylolytic enzymes in particular. Among them, amyloglucosidase is known to be secreted extracellularly in copious amounts. The current investigation was based on molecular phylogeny and taxonomy of filamentous fungi from the genus Aspergillus that are capable of producing amyloglucosidase under submerged fermentation conditions. Optimization of physical and chemical cultivation parameters were also investigated. Among the various natural isolates identified in the current study, Aspergillus fumigatus KIBGE-IB33 was selected based on maximum enzyme production. Parametric optimization resulted in the secretion of maximum amyloglucosidase in a modified starch medium. High enzyme yield was achieved after 4 days of fermentation at 30 °C in a starch-based medium (pH 7.0). The mesophilic nature of this isolate, with its broad pH range and reduced fermentation time, renders A. fumigatus KIBGE-IB33 an attractive candidate for large-scale production of amyloglucosidase for starch saccharification.