title: Biodegradation of Ochratoxin A byAspergillus tubingensisIsolated from Meju.
abstract: Ochratoxin A (OTA), a mycotoxin, contaminates agricultural products and poses a serious threat to public health worldwide. Microbiological methods are known to be a promising approach for OTA biodegradation because physical and chemical methods have practical limitations. In the present study, a total of 130 fungal isolates obtained from 65 traditional Korean meju (a fermented starter for fermentation of soybeans) samples were examined for OTA-biodegradation activity using thin-layer chromatography. Two fungal isolates were selected for OTA-biodegradation activity and were identified asAspergillus tubingensisM036 and M074 through sequence analysis of the beta-tubulin gene. After culturing bothA. tubingensisisolates in Soytone-Czapek medium containing OTA (40 ng/ml), OTA-biodegradation activity was analyzed using high-performance liquid chromatography (HPLC). BothA. tubingensisstrains degraded OTA by more than 95.0% after 14 days, and the HPLC analysis showed that the OTA biodegradation by theA. tubingensisstrains led to the production of ochratoxin α, which is much less toxic than OTA. Moreover, crude enzymes from the cultures of A. tubingensis M036 and M074 led to OTA biodegradation of 97.5% and 91.3% at pH 5, and 80.3% and 75.3% at pH 7, respectively, in a buffer solution containing OTA (40 ng/ml) after 24 h. In addition, the OTA-biodegrading fungi did not exhibit OTA production activity. Our data suggest thatA. tubingensisisolates and their enzymes have the potential for practical application to reduce levels of OTA in food and feed.
authors: Department of Integrated Biomedical and Life Science, Korea University, Seoul 02841, Republic of Korea.
authors: Sung Min
authors: SM
authors: Cho
authors: Department of Integrated Biomedical and Life Science, Korea University, Seoul 02841, Republic of Korea.
authors: Seong Eun
authors: SE
authors: Jeong
authors: Department of Integrated Biomedical and Life Science, Korea University, Seoul 02841, Republic of Korea.
authors: Kyu Ri
authors: KR
authors: Lee
authors: Department of Food Science and Technology, Yeungnam University, Gyeongsan 38541, Republic of Korea.
authors: Hemanth P K
authors: HP
authors: Sudhani
authors: Department of Food Science and Technology, Yeungnam University, Gyeongsan 38541, Republic of Korea.
authors: Myunghee
authors: M
authors: Kim
authors: Department of Integrated Biomedical and Life Science, Korea University, Seoul 02841, Republic of Korea.
authors: Sung-Yong
authors: SY
authors: Hong
authors: Department of Integrated Biomedical and Life Science, Korea University, Seoul 02841, Republic of Korea.
authors: Soo Hyun
authors: SH
authors: Chung
mesh_terms: D001230:Aspergillus / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D005285:Fermentation; D059022:Food Safety; D009793:Ochratoxins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D013025:Glycine max / Q000382:microbiology*
chemical_list: D009793:Ochratoxins; C025589:ochratoxin A
keywords: Aspergilllus tubingensis; Biodegradation; Ochratoxin A; meju