title: Identification of ochratoxin A producing fungi associated with fresh and dry liquorice.
abstract: The presence of fungi on liquorice could contaminate the crop and result in elevated levels of mycotoxin. In this study, the mycobiota associated with fresh and dry liquorice was investigated in 3 producing regions of China. Potential toxigenic fungi were tested for ochratoxin A (OTA) and aflatoxin B1 (AFB1) production using liquid chromatography/mass spectrometry/mass spectrometry. Based on a polyphasic approach using morphological characters, β-tubulin and RNA polymerase II second largest subunit gene phylogeny, a total of 9 genera consisting of 22 fungal species were identified, including two new Penicillium species (Penicillium glycyrrhizacola sp. nov. and Penicillium xingjiangense sp. nov.). The similarity of fungal communities associated with fresh and dry liquorice was low. Nineteen species belonging to 8 genera were detected from fresh liquorice with populations affiliated with P. glycyrrhizacola, P. chrysogenum and Aspergillus insuetus comprising the majority (78.74%, 33.33% and 47.06% of total) of the community from Gansu, Ningxia and Xinjiang samples, respectively. In contrast, ten species belonging to 4 genera were detected from dry liquorice with populations affiliated with P. chrysogenum, P. crustosum and Aspergillus terreus comprising the majority (64.00%, 52.38% and 90.91% of total) of the community from Gansu, Ningxia and Xinjiang samples, respectively. Subsequent LC/MS/MS analysis indicated that 5 fungal species were able to synthesize OTA in vitro including P. chrysogenum, P. glycyrrhizacola, P. polonicum, Aspergillus ochraceus and A. westerdijkiae, the OTA concentration varied from 12.99 to 39.03 µg/kg. AFB1 was absent in all tested strains. These results demonstrate the presence of OTA producing fungi on fresh liquorice and suggest that these fungi could survive on dry liquorice after traditional sun drying. Penicillium chrysogenum derived from surrounding environments is likely to be a stable contributor to high OTA level in liquorice. The harvesting and processing procedure needs to be monitored in order to keep liquorice free of toxigenic fungi.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China.
authors.forename: Amanda Juan
authors.initials: AJ
authors.lastname: Chen
authors.forename: Dan
authors.initials: D
authors.lastname: Tang
authors.forename: Ying Qun
authors.initials: YQ
authors.lastname: Zhou
authors.forename: Bing Da
authors.initials: BD
authors.lastname: Sun
authors.forename: Xiao Jin
authors.initials: XJ
authors.lastname: Li
authors.forename: Li Zhi
authors.initials: LZ
authors.lastname: Wang
authors.forename: Wei Wei
authors.initials: WW
authors.lastname: Gao
mesh_terms: D016604:Aflatoxin B1 / Q000737:chemistry; D002681:China; D002853:Chromatography, Liquid / Q000379:methods; D005506:Food Contamination / Q000032:analysis; D005658:Fungi / Q000737:chemistry*; D006035:Glycyrrhiza / Q000737:chemistry* / Q000382:microbiology*; D009183:Mycotoxins / Q000737:chemistry*; D009793:Ochratoxins / Q000737:chemistry*; D010802:Phylogeny; D012319:RNA Polymerase II / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods; D014404:Tubulin / Q000737:chemistry
chemical_list: D009183:Mycotoxins; D009793:Ochratoxins; D014404:Tubulin; C025589:ochratoxin A; D016604:Aflatoxin B1; D012319:RNA Polymerase II