Graphene‐based nanomaterials (GBNs) have attracted considerable interest nowadays due to their wide range of applications. However, very little attention has been paid to the application of nanomaterials as potential elicitors for production of valuable metabolites. Herein, aiming to earn insight into effects of nanomaterials on secondary metabolite biosynthesis by medicinal fungi, we evaluated the influence of GBNs on growth and production of ganoderic acid (GA) by Ganoderma lucidum in submerged culture. Graphene oxide (GO), reduced graphene oxide (rGO), and rGO/Fe₃O₄ nanocomposite were synthesized successfully and characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy analysis. The prepared nanomaterials were added to the culture of G. lucidum at final concentrations of 50, 100, and 150 mg/L on Day 5. The results showed that the elicitation of G. lucidum with GO and rGO decreased the cell dry weight and GA production slightly, especially in higher concentrations. However, rGO/Fe₃O₄ nanocomposite not negatively affected cell growth and improved GA production. G. lucidum growth rate responded to elicitation experiments differently and depended on the type of nanomaterials and their concentrations, but almost all GBNs caused an increase in GA content (mg/100 mg dry weight). Also, field emission scanning electron microscopy morphological study showed that under elicitation, mycelia were more condensed and tightly stacked together. The findings from this study may suggest that GBNs in low concentrations could be applied as elicitors to secondary metabolites production from higher fungus, but further environmental, physiological, and biological studies required.

中文翻译：

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不同石墨烯基纳米材料作为诱导剂对灵芝生长和灵芝酸生产的影响。

石墨烯基纳米材料（GBNs）由于其广泛的应用，如今引起了人们的极大兴趣。然而，很少有人关注纳米材料作为生产有价值代谢物的潜在诱导剂的应用。在此，为了深入了解纳米材料对药用真菌次级代谢物生物合成的影响，我们评估了 GBNs 对水下培养灵芝生长和生产灵芝酸 (GA) 的影响。氧化石墨烯 (GO)、还原氧化石墨烯 (rGO) 和 rGO/Fe ₃ O ₄成功合成了纳米复合材料，并通过 X 射线衍射、傅里叶变换红外光谱和扫描电子显微镜分析对其进行了表征。在第 5 天将制备的纳米材料以50、100 和 150 mg/L 的终浓度添加到灵芝培养物中。结果表明灵芝与 GO 和 rGO的诱导降低了细胞干重和 GA产量略有增加，尤其是在较高浓度下。然而，rGO/Fe ₃ O ₄纳米复合材料不会对细胞生长产生负面影响并提高GA产量。灵芝生长速率对诱导实验的反应不同，取决于纳米材料的类型及其浓度，但几乎所有 GBN 都会导致 GA 含量（mg/100 mg 干重）增加。此外，场发射扫描电子显微镜形态学研究表明，在诱导下，菌丝体更加凝聚和紧密堆积在一起。这项研究的结果可能表明，低浓度的 GBN 可以作为诱导剂用于从高等真菌中产生次级代谢产物，但还需要进一步的环境、生理和生物学研究。