Investigations were carried out to assess the capacity of strains of fungi
isolated from raw flowing effluent and effluent retention pond of Kaduna refinery plant
to resist and grow in the presence of lead (Pb), nickel (Ni) and cadmium (Cd) in vitro.
Fungi belonging to the genera including
Aspergillus
spp.,
Penicillium
spp.,
Fusarium
spp.,
Curvularia
spp. and
Nigrospora
spp. were isolated from the study sites. The isolates
were inoculated into duplicate 100ml flask containing 50ml of potato dextrose broth
(PDB) supplemented with 5,10 and 15ppm of Pb, Ni, and Cd. Each test isolate was
inoculated into duplicate flask containing the same medium without the heavy metals to
serve as control. All inoculated flasks were incubated aerobically at room temperature on
a rotator shaker for 7days. The mycelial mats were harvested by filtering the cultures
through preweighed filter paper (No.1). The filters bearing the mycelial mats were dried
in an oven at 70℃ for 18hours. It was observed that most of the isolates tested resisted
and grew in the medium containing 5 to 15ppm of tested heavy metals. Yield of dry
mycelia mats in the heavy metal supplemented medium were also comparable to those
grown in heavy metal free PDB medium. It was concluded that, these genera of fungi
could be playing an important role in the removal of these metals usually present in the
raw effluent during the period of residency in the retention pond through
bioaccumulation.
