Aspergillus Associated with Meju, a Fermented Soybean Starting Material for Traditional Soy Sauce and Soybean Paste in Korea

Aspergillus is an important fungal genus used for the fermentation of Asian foods; this genus is referred to as koji mold in Japan and China. A. oryzae, A. sojae, and A. tamari are used in the production of miso and shoyu in Japan, but a comprehensive taxonomic study of Aspergillus isolated from Meju, a fermented soybean starting material for traditional soy sauce and soybean paste in Korea, has not been conducted. In this study, various Aspergillus species were isolated during a study of the mycobiota of Meju, and the aspergilli were identified based on phenotypic characteristics and sequencing of the beta-tubulin gene. Most strains of Aspergillus were found to belong to the following sections: Aspergillus (n = 220), Flavi (n = 213), and Nigri (n = 54). The most commonly identified species were A. oryzae (n = 183), A. pseudoglaucus (Eurotium repens) (n = 81), A. chevalieri (E. chevalieri) (n = 62), A. montevidensis (E. amstelodami) (n = 34), A. niger (n = 21), A. tamari (n = 15), A. ruber (E. rubrum) (n = 15), A. proliferans (n = 14), and A. luchuensis (n = 14); 25 species were identified from 533 Aspergillus strains. Aspergillus strains were mainly found during the high temperature fermentation period in the later steps of Meju fermentation.

Isolation and Identification of Aspergillus Section Fumigati Strains from Arable Soil in Korea

63 strains of Aspergillus section Fumigati were isolated from 17 samples of arable soil in a central province of Korea. Based on the results of genotypic and phenotypic analyses, they were identified as Aspergillus fumigatus, A. lentulus, Neosartorya coreana, N. fennelliae, N. fischeri, N. glabra, N. hiratsukae, N. laciniosa, N. pseudofischeri, N. quadricincta, N. spinosa and N. udagawae. Among these, N. fennelliae, N. hiratsukae, N. quadricincta, and N. udagawae had not been previously recorded in Korea. The diversity of Aspergillus section Fumigati species from arable soil in Korea is also addressed.