The Combined Effects of Neem and Eucalyptus Oil on the Growth of Aspergillus niger

Asthma is a chronic condition that affects an individual's airways, leading to inflammation that diminishes oxygen intake. Asthma is a severe issue that fungi can exacerbate. The growth and development of fungi is problematic as it cause asthma due to the dampness in one’s home. Synthetic fungicides are used to combat fungi. However, the side effects produced can harm human health and the environment. Natural fungicides such as essential oils are equally effective or better than synthetic fungicides (Pezantes-Orellana et al. 2024). Studies have also shown that combined essential oils provide increased antifungal potential (Allizond et al., 2023). Therefore, the purpose of this study was to examine the combined antifungal effects of two selected essential oils, neem and eucalyptus oil, on the growth of Aspergillus niger. It was hypothesized that combining neem and eucalyptus oil would have greater antifungal effects on black mold than using each oil separately. The fungi were revived and inoculated on a plate to grow. The spores were placed on a hemocytometer for quantification. The spores were collected and distributed across two well plates along with essential oils. This was repeated on petri dishes containing potato extract dextrose. A one-way ANOVA with a 0.05 alpha value confirmed the results and proved the hypothesis true with a large statistical significance, F(3,116) = 66214.58, p < 0.001. The post-hoc Tukey test concluded that every group had a statistical difference except the combination versus eucalyptus groups, showing that the addition of both types of oils can inhibit fungal growth more.