Assessment of paint-pigment degrading microorganisms from paint industries effluent-contaminated sites in aba, south-east nigeria

The potential of microorganisms isolated from paint industry effluent-polluted soils to degrade the constituents of the effluents and contaminant removal efficiency after the remediation period were evaluated. Samples were collected from six different paint industries in Aba. Samples from the various paint industries reveals sample F showed the highest bacterial plate counts of 6.21±0.20 x 104cfu/g while samples B and D had the least bacterial counts of 1.30±0.20 x 104cfu/g and 1.30±0.31 x 104cfu/g respectively. The fungal counts of the polluted soils indicates sample D as having the highest count of 2.30±0.24 x 104cfu/g while sample A had the least count of 1.00±0.30 x104cfu/g. Total Paint Utilizing Fungal (TPUF) counts ranges from 1.23±0.02 x 104cfu/g to 3.45±0.10 x 104cfu/g and showed a significant difference between sample C and the control (p<0.05). The bacterial isolates from the contaminated soil include Pseudomonas spp., Escherichia coli, Citrobacter spp., Klebsiella spp., Proteus spp., Enterobacter spp., Providencia rettgeri, Shigella flexneri, Staphylococcus spp., Streptococcus spp. and Enterococcus spp. while the fungal isolates include Saccharomyces cerevisiae, Rhodotorula species, Rhizopus species, Aspergillus niger, Aspergillus flavus and Penicillum notatum. The counts of actual paint utilizing fungi were relatively lower than the heterotrophic groups. The paint degrading microorganisms isolated from the paint industry effluent polluted soils include paint effluent bacterial degraders: Pseudomonas spp. (33.3%), Escherichia coli(33.3%),, Citrobacter spp. (25%), Klebsiella spp.(25%), Proteus spp.(25%), Enterobacter spp.(12.5%). and Providencia rettgeri(12.5%), While the fungal paint effluent degraders include Geotrichum candidum(33.3%), Pichia kudriavzevii(33.3%), Fusarium sp.(25%), Aspergillus niger(25%), Penicillium funiculosum(25%) and Mucor sp.(12.5%). Geotrichum candidum strain GAD1 (MN63874.1) and Pichia kudriavzevii strain (MK811096.1) showed highest degrees of growth indicated by high turbidities during the screening test. This study showed that majority of the Indigenous organisms has the ability to utilize paints as their sole carbon source hence are the major bioremediating agents in the sampling areas.