The enumeration and characterization of microorganisms from laboratory effluents in Madonna University laboratories were carried out. The total aerobic plate count, coliform count, Escherichia coli count and fungal count were investigated using pour plate technique in nutrient agar, MacConkey agar, eosine methylene blue agar and Sabouraud dextrose agar respectively. The statistical analysis used ANOVA. The mean total aerobic plate count for the treated and untreated effluents ranged from 0Log10cfu/mL to 4.47 ± 0.01Log10cfu/mL and 6.97 ± 0.10Log10cfu/mL to 7.21 ± 0.20Log10cfu/mL respectively. The fungal count ranged from 0 Log10cfu/mL to 3.82 ± 0.17Log10cfu/mL and 5.98 ± 0.10Log10cfu/mL to 6.57 ± 0.14Log10cfu/mL respectively. The mean coliform and Escherichia coli counts for the untreated effluents ranged from 6.82 ± 0.14Log10cfu/mL to 7.09 ± 0.10Log10cfu/mL and 0Log10cfu/mL to 2.2 ± 1.24Log10cfu/mL respectively. There was no coliform and Escherichia coli counts for the treated effluents. Bacterial genera isolated were Escherichia coli, Klebsiella species, Staphylococcus aureus, Streptococcus species, Micrococcus species and Pseudomonas species. The fungal genera isolated were Penicillum species, Aspergillus species, Rhizopus species and Yeast species. High microbial counts observed in the untreated effluents when compared with the treated effluents showed the need for proper treatment of laboratory effluents before disposal.
