Identification and Characterization of Aspergillus oryzae Isolated from Soybean Products in Sunchang County

Eunmi Lim1   Ji Young Lee1   Mohammed A. Abdo Elgabbar2   Kap-Hoon Han2   Bo-Soon Lee3   Yong Sik Cho4   Hyoun-Young Kim1   


In this study, we attempted to isolate fungi from soybean fermented foods produced in Sunchang County and to identify Aspergillus oryzae from fungal isolates. Ten fungal isolates were identified with β -tubulin gene. According to the sequences of β -tubulin gene, ten fungal isolates were identified as A. oryzae/flavus complex. For further identification of the ten of fungal isolates, omtA gene, one gene of the aflatoxin biosynthesis gene cluster, was sequenced and the sequences were compared with those of A. oryzae and A. flavus strains from the GenBank database. In addition, identification of the ten fungal isolates was further confirmed using the PCR amplicon of norB and cypA intergenic region, in which a deletion was recognized relative to A. flavus and A. parasiticus. The amplicon size of the ten fungal isolate strains was smaller than those of A. flavus and A. parasiticus, but the same as that of the reference A. oryzae strain. These results indicated that the ten isolates should be identified as A. oryzae. The protease activity in rice koji made with 6, 13, 17, 27, 37 and 38 of strain, respectively was twice higher than that in control. The kojis made with nine of the A. oryzae isolates, respectively, did not produce aflatoxin, suggesting that the strains could possibly be used as starters for soybean products.


본 논문은 농촌진흥청 연구사업(세부과제명:장류(된장) 제조에 적합한 종균 선발(곰팡이) 및 제조기술 개발, 세부과제번호:PJ00999002)의 지원에 의해 이루어진 것임.

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