Penicillium and Aspergillus Species Characterization: Adaptation to Environmental Factors and Sensitivity to Aqueous Medicinal Plants Extracts

Abstract

In this study, nine fungal species belonging to genus Aspergillus (6) and Penicillium (3), which were found on whiteflies cadavers adults collected from cucumber cultivation fields in Basra Iraq, are characterized regarding mycelial growth rate at different culture media, pH levels and temperature degrees, and their sensitivity under in vitro assay to aqueous extracts of Ocimum sanctum, Mentha arvensis and Allium sativum at different concentrations. Aspergillus and Penicillium species showed a wide range of tolerance to different culture media, pH levels and temperature degrees which decrease significantly there mycelial growth rate, although no of these parameters were able to inhibit them completely. This study has demonstrated further information on conditions favoring mycelial growth of Aspergillus and Penicillium species (at pH 6 and temperature between 25 and 30°C). In sensitivity assays, all tested species were susceptible to the aqueous extracts. The mycelial growth inhibition was significantly higher with the high concentrations of aqueous extract. The aqueous M. arvensis extracts at 150 mg/mL succeed to decrease the mycelial growth of A. parasiticus (82.5%) and A. fumigatus (81.67%). It appears that the growth rates of A. parasiticus (94.17%) and A. fumigatus (93.38%) was significantly inhibited by the aqueous A. sativum extracts at 150 mg/mL. A. fumigatus (80.83%) and A. parasiticus (76.67%) were high significantly inhibited by the aqueous extracts of O. sanctum at 150 mg/mL. The response of Aspergillus spp. and Penicillium spp. to natural situations and aqueous extracts is important to understand their behaviour and to predict fungal spoilage on crops fruits.