Heidtmann-Bemvenuti Renata, Tralamazza Sabina Moser, Jorge Ferreira Cláudia Fetter, Corrêa Benedito, Badiale-Furlong Eliana
Laboratory of Mycotoxins and Food Science, Chemical and Food School, Federal University of Rio Grande, RS, Brazil.
Laboratory of Mycotoxins and Mycotoxigenic Fungi, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
J Sci Food Agric. 2016 Sep;96(12):3998-4008. doi: 10.1002/jsfa.7591. Epub 2016 Feb 17.
A search is underway for new solutions to counter farm loss caused by fungal contamination of grains, since the active agents of fungicides can remain in the environment and contribute to the development of resistant and toxigenic species. In this study, the antifungal activity of natural compounds (γ-oryzanol, phenolic extract of neem seeds and of rice bran) was assessed on three toxigenic strains of Fusarium graminearum isolated from wheat, rice and barley. Their efficacy was compared to that of synthetic fungicides. The halo diameters were measured and the susceptible pathways were determined by the levels of structural compounds and activities of enzymes involved in the primary metabolism of the microorganisms. Moreover, mycotoxin production and gene expression were examined.
Phenolic extracts were more effective at inhibiting F. graminearum than was γ-oryzanol, as evidenced by the minimum inhibitory concentration. This work contributed to the elucidation of the mechanism of action of natural antifungal agents.
Natural antifungals effectively inhibited fungal growth, especially via the inactivation of the enzymatic systems of F. graminearum. Natural antifungals inhibited mycotoxin production by the fungi. A correlation between the levels of deoxynivalenol and the expression of Tri5 gene was observed, indicating that the natural compounds could be considered alternatives to synthetic antifungals. © 2015 Society of Chemical Industry.
由于杀菌剂的活性成分会残留在环境中，并促使耐药菌和产毒菌的产生，因此人们正在寻找新的解决方案来应对谷物真菌污染造成的农业损失。在本研究中，评估了天然化合物（γ-谷维素、印楝种子和米糠的酚类提取物）对从小麦、水稻和大麦中分离出的三种禾谷镰刀菌产毒菌株的抗真菌活性。将它们的功效与合成杀菌剂进行了比较。测量了抑菌圈直径，并通过微生物初级代谢中涉及的结构化合物水平和酶活性确定了敏感途径。此外，还检测了霉菌毒素的产生和基因表达。
酚类提取物在抑制禾谷镰刀菌方面比γ-谷维素更有效，最低抑菌浓度证明了这一点。这项工作有助于阐明天然抗真菌剂的作用机制。
天然抗真菌剂能有效抑制真菌生长，尤其是通过使禾谷镰刀菌的酶系统失活。天然抗真菌剂抑制了真菌产生霉菌毒素。观察到脱氧雪腐镰刀菌烯醇水平与Tri5基因表达之间的相关性，表明天然化合物可被视为合成抗真菌剂的替代品。© 2015化学工业协会。
