A magnetic nanocomposite combined with cinnamic acid for capture–inhibition–separation of Aspergillus fumigatus

Abstract

Abstract To prevent the generation of drug‐resistant fungi from long‐term exposure to microorganisms, cinnamic acid (CA), a natural effective antifungal agent, was successfully coupled with poly‐dopamine magnetic nanoparticles (CA–DMPs). Due to the low solubility of CA, the saturated solution of CA (1.61 mg/mL, 45°C) had no antifungal effect. Contrarily, CA–DMPs showed a good antifungal effect. The resulting heat‐stable and reusable antifungal CA–DMP composite particles were superparamagnetic (49.79 emu g−1) and had an average diameter of 25.01 ± 1.36 nm. The novel composites showed good antifungal activity and excellent recycling performance, the sterilization rate of CA–DMPs remained above 96% after seven consecutive running cycles. CA–DMP composites could damage the fungal cell wall and membrane system, leading to the leakage of cell inclusions. Furthermore, transcriptome analysis of Aspergillus fumigatus treated with composites showed that 466 differentially expressed genes were primarily associated with cell wall membrane, membrane transporters, energy metabolism, genetic expression, and oxidation–reduction. The effect of CA–DMPs in inducing mitochondrial membrane dysfunction might result in the disruption of energy metabolism and REDOX homeostasis. Overall, the results reported herein provide new insight into the potential antifungal nanomaterials. In vitro antifungal experiments performed on cherry tomatoes confirm the application potential of the synthesized material in the field of fruit and vegetable preservation.

Keywords

• antifungal activity
• Aspergillus fumigatus
• cinnamic acid
• poly‐dopamine magnetic nanoparticles
• transcriptome