Anaerobic denitrification and biotechnological potentials of filamentous fungi isolated from coastal marine sediment
By: C. N. Ariole, N. Ofuase
Key Words: Marine fungi, Coastal sediment, Anaerobic denitrification, Enzyme, Antibacterial activity
Int. J. Micro. Myco. 4(3), 8-15, October 2016.
The anaerobic denitrification, antibacterial and enzyme-producing potentials of filamentous fungi isolated from sediment collected from the coastal region of the Niger Delta in Bonny Island, Nigeria were investigated. The fungi were aerobically isolated using spread plate method on sterile acidified potato dextrose agar. The capability of isolates to survive under anoxic environment was assessed by incubating cultured plates in anaerobic jars. Four isolates were studied for growth and denitrifying capacity in mineral salts supplemented with nitrate, glucose and peptone for 14 days under anaerobic conditions. Agar diffusion assay was employed for antibacterial activity of isolates against fish and shellfish pathogens (Aeromonas hydrophila and Vibrio parahaemolyticus). The isolates were screened for production of amylase, cellulase, protease and lipase using starch agar, cellulose agar, skim milk agar and tributyrin agar correspondingly. Twelve fungal isolates of the genera Fusarium, Aspergillus, Cladosporium, Penicillium, Acremonium and Trichoderma were isolated at different frequencies with Aspergillus predominating. A decrease in nitrate concentration and accumulation of nitrite and ammonia were observed at the end of the denitrification study. Nine fungal isolates (75%) were found active against the pathogens. The percentage composition of amylase, cellulase, protease and lipase producing strains were 83.3, 83.3, 75.0 and 66.7% respectively. The denitrification pattern and organic substrate degradation ability observed showed that fungi can play a role in nitrogen and carbon cycles occurring in marine sediment. The results also revealed that the indigenous multiple enzyme-producing fungi with antibacterial potential isolated in this study can be efficiently used for biotechnological applications.