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.
Highlights
Liquorice, the root of the leguminous Glycyrrhiza plant species (Glycyrrhiza uralensis Fisch., Glycyrrhiza inflate Bat. and Glycyrrhiza glabra L.), is a popular botanical with a long history of cultivation and use in China
Forty-one and 32 sequences recovered from GenBank that were associated with Penicillium subgenus Penicillium sect
Penicillium polonicum strain CGMCC3.15264 (G3323) was excluded from this clade, but subsequent morphological observations suggests that it should be included in this lineage
Summary
The root of the leguminous Glycyrrhiza plant species (Glycyrrhiza uralensis Fisch., Glycyrrhiza inflate Bat. and Glycyrrhiza glabra L.), is a popular botanical with a long history of cultivation and use in China. Liquorice is a common dietary supplement and its derivatives have been given Generally Recognized as Safe (GRAS) status in the USA in 1985 [2]. Liquorice and its derivatives are used as flavoring and sweetening agents in confectionery and other food products, such as beverages and chewing gum [3,4]. The wild plants of liquorice (G. uralensis, G. inflate and G. glabra) are primarily distributed in arid desert and grassland areas in Gansu, Ningxia, Xinjiang and Inner Mongolia in northwest China, among which G. uralensis is the most widely distributed variety [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
