RESUMO
Three nitrogenous dump-sites viz. urinary spots; poultry dung compost and nitrogenous fertilizer storage site; and a non-nitrogenous site (as control) in Port Harcourt Metropolis; Rivers State of Nigeria; were characterised for their aerobic ureolytic bacteria isolates. The nitrogenous waste sites compared with the non-nitrogenous site clearly indicated that the TCFU of bacteria was significantly lowered as a result of dumping of all forms of nitrogenous wastes (ANOVA P = 0.019). Tentatively and cumulatively identified 10 randomly isolated aerobic bacterial species from the sites included Staphylococcus 5(12.5)*; Streptococcus 2(5.0); Proteus 8(20.0); Serratia 2(5.0); Flavobacterium /Xanthomonas 3(7.5); Escherichia coli 4(10.0); Klebsiella /Enterobacter 2(5.0) and Pseudomonas 4(10.0); Bacillus and other Gram-positive rods 10(25.0) were frequently isolated in all the samples. From these isolates; urease activity was more elaborated in the nitrogenous fertilizer dump-site in which three isolates of Proteus sp and three of Pseudomonas sp elaborated urease activity. While urease activity was also elaborated by Proteus (2 isolates) and the Klebsiella /Enterobacter (one isolate) in the urinary spot only (2 isolates) of Proteus elaborated urease activity in the poultry-dung site. It was not clear if there were physiological factors arising from human urine and poultry dung that might have limited the activity Pseudomonas sp to the nitrogenous fertilizer only. The probable source of variability in the type of urea degrading bacterial isolated from the sites and the effect of compromising microbiological environmental cleansing capability were discussed