Seung-Beom Hong 1* †, Sung-Yong Hong 2†, Kyu-Hong Jo 1, Young-Sik Kim 3, Jong-Ho Do 4, Ji-Young Do 4, Seok- Beom Noh 5, Han-Hong Yoon 5 and Soo-Hyun Chung 2*
1Agricultural Microbiology Divison, National Academy of Agricultural Science, RDA, Wanju 55365, Korea
2School of Biosystem and Biomedical Science, Korea University, Seoul 02841, Korea
3Hakyeong Fermentation Co., Hwaseong 18324, Korea
4Suwon Fermentation Co., Hwaseong 18520, Korea
5Chungmoo Fermentation Co., Ulsan 44956, Korea
Correspondence to funguy@korea.kr, chungs59@korea.ac.kr
Korean Journal of Mycology (Kor J Mycol) September, 2015, 43(3):149-157.
https://doi.org/10.4489/KJM.2015.43.3.149
Received: September 9, 2015; Revised: September 14, 2015; Accepted: September 22, 2015
Published: September, 2015.
© The Korean Society of Mycology
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
We examined taxonomic characteristics and safety of eight Nuruk molds that are widely used for making soybean paste, soy sauce and alcoholic beverages in Korea. HK1 from Hakyeong Fermentation Co., SW101 from Suwon Fermentation Co., CF1001, CF1002, CF1003 from Chungmoo Fermaentation Co. and KACC 93210 are yellow-Nuruk molds, and SW201 from Suwon Fermentation Co. and CF1005 from Chungmoo Fermentation Co. are white-Nuruk molds. Six strains of yellow-Nuruk molds were identified as Aspergillus oryzae. HK1, SW101, CF1001 and CF1003 of yellow-Nuruk molds have middle length of stipes (711~1,121 µm), and CF1003 (for sake) produced less conidia and more hyphae than HK1, SW101 and CF1001 (for soybean paste). CF 1002 used for soy sauce has shorter stipes (543 µm) and is clustered into IBLB- group based on omtA gene analysis although the other yellow-Nuruk molds are clustered into ICAo group. KACC 93210 isolated from traditional Korean Meju has very short stipes (average 270 µm), and showed velvety colonies although the others showed floccose colonies. The strain has different DNA sequences of omtA gene from other strains in NCBI GenBank as well as strains used in Korea, suggesting that it is unique from other strains published. SW201 and CF1005 of white-Nuruk molds were identified as Aspergillus luchuensis or A. luchuensis mut. Kawachii that is known as safe, non-toxigenic fungus. The six strains of yellow-Nuruk molds did not produce mycotoxins including aflatoxin, cyclopiazonic acid, and sterigmatocystin. Therefore, eight strains of Nuruk molds used for making soy sauce, soybean paste and alcoholic beverages in Korea were proved to be safe in this study.
Aspergillus luchuensis, Aspergillus oryzae, Nuruk molds, Safety, Taxonomic characterization