Microbiological and physicochemical analysis of different water samples used for domestic purposes in Abeokuta and Ojota, Lagos State, Nigeria

Abstract

Samples of tap, well, stream, and wastewaters were collected from Abeokuta and Ojota (both in Nigeria) state and analyzed microbiologically and physico-chemically using standard methods. Total viable count was by pour plate technique while most probable number (MPN) counts were by the multiple tube fermentation technique. The pH (at 25oC) ranged from 3.10 to 8.33 for the untreated raw water samples while temperature ranged from 28 to 30oC while the turbidity of the water and waste water samples ranges from 0.08 to 1.00. All the water samples were found to harbor coliforms organisms in numbers greater than the required WHO/FAO standards for water. The total viable counts for all the water samples were generally high exceeding the limit of 1.0 x 102 cfu/ml for water. The MPN count ranges from 9.3 to 44 MPN/100 ml. The fecal coliform counts on EMB agar plate ranged between 5 and 48 cells, also exceeding the standard limit for water. The Isolated organisms were identified to be Staphylococcus aureus, Salmonellaspecies, Escherchia coli, Pseudomonas aerugionosa, Enterobacter aerogenes, Bacillus species, Proteus species, Klebsiella species, Flavobacterium species and Acinetobacter species. Key words: Microbiological analysis, standard methods, water, WHO/FAO.