Molecular and morphological identification of fungal species isolated from rice meju

Abstract

The microflora of natural fermented Korean rice meju are assumed to be diverse, but has not yet been investigated. The fungi was isolated and identified from rice meju on the bases of morphology, culture characteristics, and molecular approaches of internal transcribed spacer and β-tubulin gene sequencing, and their enzyme activities were determined. Six species of fungi were primarily isolated from rice meju, specifically Aspergillus candidus, Aspergillus tritici, Cladosporium oxysporum, Penicillium commune, Penicillium griseofulvum, and Rhizomucor variabilis var. regularior. All isolates produced protease (5.17–15.78), and all strains except Mucor circinelloides PR06 expressed amylase activities (0.04–0.23). In comparison, lipase was produced by zygomycetous fungi isolates (1.70–0.25) and Aspergillus oryzae PR07 (0.68). The enzyme producing fungal strains might be involved in the rice meju fermentation. The identification of fungal diversity in meju is useful for understanding the fermentation processes and these strains might be used in the fermentation of foods.