Chemical characterization, antimicrobial, antioxidant and larvicidal activities of certain fungal extracts

Fungal extracts are considered a promising source of bioactive compounds that represent the basic core of the drug industry. This study aimed at exploring the antimicrobial, antioxidant and larvicidal activities of three ethyl acetate extracts of three fungal isolates Fusarium oxysporum, Aspergillus fumigatus and Penicilluim griseofulvum. These fungi were isolated from sediment samples collected in water courses of three Egyptian governorates; Giza, Qalubeya and Gharbeya, during a year from January to December 2019, molecularly identified using 18Sr RNA technique and were grown on rice medium for 14 days and extracted with ethyl acetate. GC-MS examination of the extracts led to identification of 15, 29 and 24 compounds, respectively. Hexadecanoic acid was detected as a main component in the investigated extracts. Moreover, in Folin-Ciocalteu's assay, the tested fungal extracts showed noticeable total phenolic contents (TPCs) values of 115.84, 88.24 and 73.22, respectively for Aspergillus fumigatus, Penicillium griseofulvum and Fusarium oxysporum. Additionally, Aspergillus fumigatus extract exhibited strong total antioxidant capacity (TAC) value of 409.46 mg AAE/g dry extract, followed by Penicillium griseofulvum and Fusarium oxysporum extracts with TAC values of 299.28 and 281.31 mg AAE/g dry extract, respectively. All extracts exhibited antimicrobial activities against Staphylococcus aureus (G+ve bacterium), Escherichia coli (G-ve bacterium), Candida albicans (yeast) and Aspergillus niger (Fungus). Also, the extracts showed high larvicidal activity against miracidia and cercariae of Schistosoma mansoni. In conclusion, Fusarium oxysporum, Aspergillus fumigatus and Penicilluim griseofulvum are excellent sources of bioactive compounds which have multiple biological effects.