中文摘要：此前有研究检测了生腰果仁的真菌污染情况，主要针对曲霉及黄曲霉毒素产毒菌，发现生腰果仁受黑曲霉污染程度很高，但没有黄曲霉毒素污染。为了弄清包括霉菌毒素在内的次生代谢物的多样性，以及这些黑曲霉种类可能产生并造成生腰果仁污染，本研究从腰果仁中分离了150株黑曲霉，并采用液相色谱-高分辨质谱(LC-HRMS)法分析其次生代谢物。结果从样品中检测到了三类霉菌毒素：伏马菌素、赭曲霉素A和裸麦酸，意味着这些毒素可能造成腰果污染。
外文摘要：a previous study, raw cashew kernels were assayed for the fungal contamination focusing on strains belonging to the genus Aspergillus and on aflatoxins producers. These samples showed high contamination with Aspergillus section Nigri species and absence of aflatoxins. To investigate the diversity of secondary metabolites, including mycotoxins, the species of A. section Nigri may produce and thus threaten to contaminate the raw cashew kernels, 150 strains were isolated from cashew samples and assayed for their production of secondary metabolites using liquid chromatography high resolution mass spectrometry (LC-HRMS). Seven species of black Aspergilli were isolated based on morphological and chemical identification: A. tubingensis (44%), A. niger (32%), A. brasiliensis (10%), A. carbonarius (8.7%), A. luchuensis (2.7%), A. aculeatus (2%) and A. aculeatinus (0.7%). From these, 45 metabolites and their isomers were identified. Aurasperone and pyranonigrin A, produced by all species excluding A. aculeatus and A. aculeatinus, were most prevalent and were encountered in 146 (97.3%) and 145 (95.7%) isolates, respectively. Three mycotoxins groups were detected: fumonisins (B2 and B4) (2.7%) ochratoxin A (13.3%), and secalonic acids (2%), indicating that these mycotoxins could occur in raw cashew nuts. Thirty strains of black Aspergilli were randomly sampled for verification of species identity based on sequences of β-tubulin and calmodulin genes. Among them, 27 isolates were positive to the primers used and 11 were identified as A. niger, 7 as A. tubingensis, 6 as A. carbonarius, 2 as A. luchuensis and 1 as A. welwitschiae confirming the species names as based on morphology and chemical features. These strains clustered in 5 clades in A. section Nigri. Chemical profile clustering also showed also 5 groups confirming the species specific metabolites production.
外文关键词：Secondary Metabolites；Aspergillus Section Nigri ；Raw Cashew Nuts；LC-HRMS
作者：Lamboni, Y；Nielsen, KF；Linnemann, AR；Gezgin, Y；Hell, K；Nout, MJR；Smid, EJ；Tamo, M；van Boekel, MAJS；Hoof, JB；Frisvad, JC
作者单位：Int Inst Trop Agr
期刊名称：PLOS ONE
期刊影响因子：3.057
出版年份：2016
出版刊次：10
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