Occurrence of mycotoxins and yeasts and moulds identification in corn silages in tropical climate
Occurrence of mycotoxins and yeasts and moulds identification in corn silages in tropical climate
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DOI：
10.1111/jam.13057
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发表时间：
2016-05-01
影响因子：
4
通讯作者：
Schwan, R. F.
中科院分区：
文献类型：
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作者：
Carvalho, B. F.;Avila, C. L. S.;Schwan, R. F.
目的本研究旨在鉴定巴西米纳斯吉拉斯州南部玉米青贮中的酵母菌和霉菌以及检测真菌毒素。方法和结果选取36个养殖场的青贮饲料，对其干物质、粗蛋白质、粗脂肪、灰分、中性洗涤纤维、非纤维碳水化合物和真菌毒素含量、酵母和霉菌数量、pH值和温度进行分析。检出频率较高的真菌毒素为黄曲霉毒素（777%）、赭曲霉毒素（333%）和玉米赤霉烯酮（222%）。霉菌毒素浓度与霉菌存在之间无显著相关性。pH值与赭曲霉毒素浓度呈负相关。青贮饲料中均有烟曲霉生长。采用培养依赖法鉴定了10种不同的酵母菌：双假丝酵母菌、乙醇假丝酵母菌、白色假丝酵母菌、东方假丝酵母菌、马氏克卢维酵母菌、manshurica Pichia、膜性毕赤酵母Pichia、酿酒酵母菌Saccharomyces cerevisiae、ashitrichosporon和japonicum。另外6种不同的酵母菌用培养不依赖的方法鉴定。结论青贮饲料霉菌毒素污染率较高，占青贮饲料的916%。结果表明，常规培养与PCR-DGGE相结合，可以较好地描述玉米青贮相关微生物群。研究的意义和影响本研究提供了玉米青贮发酵动力学的信息，我们的研究结果与青贮发酵的优化有关。
AimsThis study was aimed to identify yeasts and moulds as well as to detect mycotoxin in corn silages in southern Minas Gerais, Brazil.Methods and ResultsCorn silages from 36 farms were sampled to analyse dry matter, crude protein, ether extract, ash, neutral detergent fibre, nonfibre carbohydrates and mycotoxins contents, yeasts and moulds population, pH and temperature values. The mycotoxins found in high frequency were aflatoxin in 777% of analysed samples, ochratoxin (333%) and zearalenone (222%). There was no significant correlation between the mycotoxin concentration and the presence of moulds. The pH was negatively correlated with ochratoxin concentration. Aspergillus fumigatus was identified in all silages that presented growth of moulds. Ten different yeast species were identified using the culture-dependent method: Candida diversa, Candida ethanolica, Candida rugosa, Issatchenkia orientalis, Kluyveromyces marxianus, Pichia manshurica, Pichia membranifaciens, Saccharomyces cerevisiae, Trichosporon asahii and Trichosporon japonicum. Another six different yeast species were identified using the culture-independent method.ConclusionsA high mycotoxin contamination rate (916% of the analysed silages) was observed. The results indicated that conventional culturing and PCR-DGGE should be combined to optimally describe the microbiota associated with corn silage.Significance and Impact of the StudyThis study provides information about the corn silage fermentation dynamics and our findings are relevant to optimization of this silage fermentation.