Magnoli C, Violante M, Combina M, Palacio G, Dalcero A
Departamento de Microbiología e Inmunología, Universidad Nacional de Río Cuarto, Córdoba, Argentina.
Lett Appl Microbiol. 2003;37(2):179-84. doi: 10.1046/j.1472-765x.2003.01376.x.
The aims of this work were to evaluate the mycoflora and to identify the species of Aspergillus with the potential to produce ochratoxin A (OA) from different wine grape varieties from Mendoza, Argentina. Likewise, the capacity to produce OA by Aspergillus section Nigri was studied.
Fifty samples of wine grapes were obtained from a winery of Mendoza province, Argentina. The surface-disinfection method was used for mycoflora determination using the medium dichloran 18% glycerol agar (DG18). Alternaria, Aspergillus and Penicillium were identified at species level. OA production was tested in 63 strains belonging to section Nigri. Alternaria genus was the most frequent (80% of the samples) followed by Aspergillus (70%). Alternaria alternata was the only specie identified from the Alternaria genus, followed by A. niger var. niger, A. flavus among others. From Penicillium genus, P. crysogenum was the most frequent specie. From 63 strains of Aspergillus section Nigri, 41.3% were OA producers. The levels of produced toxin ranged from 2 to 24.5 ng ml-1 of culture medium.
The presence of ochratoxigenic strains of Nigri section in this substrate suggests that they may be an important source of OA in grapes from tropical and subtropical zones. Therefore, the industry should work further to diminish the growth of these fungi and mycotoxins formation in grapes, with the aim to reduce OA content in wine products.
The wine grape contamination with A. alternata and Aspergillus section Nigri was significant.
本研究旨在评估阿根廷门多萨不同酿酒葡萄品种上的真菌区系，并鉴定具有产生赭曲霉毒素A（OA）潜力的曲霉种类。同样，对黑曲霉组产生OA的能力进行了研究。
从阿根廷门多萨省的一家酿酒厂采集了50个酿酒葡萄样本。采用表面消毒法，使用二氯苯胺18%甘油琼脂（DG18）培养基测定真菌区系。在种水平上鉴定了链格孢属、曲霉属和青霉属。对属于黑曲霉组的63个菌株进行了OA产生测试。链格孢属是最常见的（占样本的80%），其次是曲霉属（占70%）。链格孢是链格孢属中唯一鉴定出的物种，其次是黑曲霉变种黑曲霉、黄曲霉等。在青霉属中，产黄青霉是最常见的物种。在63个黑曲霉组菌株中，41.3%能够产生OA。产生的毒素水平在每毫升培养基2至24.5纳克之间。
该基质中存在黑曲霉组产赭曲霉毒素菌株表明，它们可能是热带和亚热带地区葡萄中OA的重要来源。因此，该行业应进一步努力减少这些真菌在葡萄中的生长和霉菌毒素的形成，以降低葡萄酒产品中的OA含量。
酿酒葡萄被链格孢和黑曲霉组污染的情况较为严重。
