ISOLATION, CHARACTERIZATION AND ANTIMICROBIAL POTENTIALS OF EXTREMOPHILIC FUNGI FROM SELECTED LOCATIONS IN LAGOS AND RIVERS STATES OF NIGERIA

Abstract

Experiments were conducted to isolate fungi from extreme environment and determine their activity against different human pathogenic strains by agar well diffusion method. In this study, water and soil samples were collected from Eko Bar Beach and also from the jetty side of the beach from which halophytes were isolated. Soil sample were also collected from Eleme in Port Harcourt from which bacidophilus organisms were isolated and soil samples were collected from Oginigba Trans Amadi in Port Harcourt from which acidophilus organisms were isolated. The following fungi were isolated from the halophytic habitat: Aspergillus niger and Trichoderma viridae from Beach soil; Aspergillus chevalieri, Aspergillus amstelodami, Mucor plumbeus, Geotrichum candidum from Jetty side water sample, and Aspergillus terreus, Phialophora fastigiata and Talaromyces thermophilus from Beach water sample. Mucor racemosus and Trichoderma reesii were isolated from the basic habitat (Eleme soil), while Gliocladium deliquescens, Paecilomyces varioli, Penicillum oxalicium and Penicillum fellutanum were isolated from the acidic habitat (Oginigba Trans Amadi soil). The fungi were cultivated in a culture medium and its secondary metabolites were extracted and used for antimicrobial susceptibility test. All the fungal culture filtrate extracts exhibited remarkable antimicrobial activities against the test human pathogenic organisms. Although Shigella flexneri was resistant to the extracts of Trichoderma viridae, Phialophora fastigiata and Penicillum fellutanum, while Salmonella typhi was also resistant to Aspergillus chevalieri extract. Gas chromatographic analysis revealed the presence of some biologically active compounds in the fungal extracts, which could be responsible for its antimicrobial action against the test fungi and bacteria. Some of the major biologically active compounds in the extracts are; Avilamycin, Capuramycin, , 8_11- Octadecadienoic acid, Homosyringic Acid, Homosyringic acid, 5_8-Dimethylquinolin, Cycloheximide, Marinomycins A-D, and Ipomycin. It was concluded that halophilic fungi from Eko Bar Beach, basidophilic fungi from Eleme soil and acidophilic fungi from Oginigba Trans Amadi soil are diverse, they produce compounds with good antimicrobial activity and could be suitable sources of new antimicrobial natural products.