The Antifungal Efficacy of Handroanthus impetiginosus Extract (Pau D’Arco) on the Growth of Aspergillus niger

Fungal contamination poses significant threats to various industries, highlighting the need for natural antifungal agents. Handroanthus impetiginosus has been historically reported to exhibit significant antimicrobial and antifungal, but its effects on certain filamentous fungi are limited. The purpose of this study aimed to evaluate the antifungal properties of Pau D’Arco extract combined with olive oil, against Aspergillus niger as an application to develop a natural fungal pesticide. The hypothesis stated that increasing concentrations of Pau D’Arco would inhibit the growth of A. niger, due to antifungal compounds being able to restrict and inhibit fungal growth. Three groups were tested for 90 trials: one control and two experimental with varying Pau D’Arco concentrations. 30 discs were soaked in each suspension and placed in the center of each quadrant of A. niger plates grown on potato dextrose agar. The plates were incubated for 48 hours. No measurable and visual zone of inhibition was observed, and fungal overgrowth occurred in all 90 trials. It was determined that fungal overgrowth was due to environmental factors or a low-quality extract. Factors such as pH, oxygen levels, moisture, and chemical fumes would cause a deviation in the natural growing pattern of A. niger, leading to spiking proliferation and overgrowth of the fungi. Strictly controlling environmental factors and using higher-quality extracts can produce better results. In addition, carefully researching higher-quality extracts that are more soluble in oil and can contain higher amounts of antifungal compounds can be beneficial to obtain better results.