DEGRADATIVE ABILITIES OF MICROORGANISMS FROM SELECTED RIVERS IN AKURE, NIGERIA ON SOME DETERGENTS AND SOAPS

Abstract

Water samples were collected from five different rivers in Akure, namely; Ala, Majo, Ero, Owena and Otere. The rivers were selected based on the activities of the inhabitants of nearby settlements. Omo, Ariel and Sunlight detergents, B29 and Canoe soaps sourced from Akure main market were used for the research which was carried out between the months of June and November, 2013. The physico-chemical properties of the water samples were determined. A survey of the microbial load and surfactant degrading microbes were carried out. The total bacterial load of the water samples range from 7.20 ± 0.69(x103 cfu/ml) to 40.0 ± 2.31 (x103 cfu/ml), while the surfactant degrading bacteria counts was within the range of 0.33±0.02 (x103 cfu/ml) to 5.37±2.3(x103cfu/ml). The total fungi count was within the range of 5.00±1.15(x102 sfu/ml) to 11.0 ±1.73 (x102 sfu/ml). Surfactants degrading fungi counts were within the range of 0.60 ± 0.11 (x102 sfu/ml) to 1.20 ± 0.05(x102 sfu/ml). The surfactant degrading bacteria isolated from the water samples are Escherichia coli, Klebsiella sp, Enterobacter sp, Bacillus subtilis, Citrobacter sp, Pseudomonas putida, Proteus sp, Staphylococcus albus, Exiguobacterium profundum and Klebsiella oxytoca, while the surfactant degrading fungi isolated from the water samples are Articulospora inflate, penicilium italicum, Aspergillus flavus, Trichoderma viridae, Varicosporum elodeae, Gonatobotryum apiculatum and Aspergillus saprophyticus. Omo, Ariel and Sunlight detergents, B29 and Canoe soaps sourced from the Akure main market were subjected to 50-days bacterial and fungal degradation by the isolates, so as to extensively monitor the degradability of the surfactants. Sunlight detergent, canoe and B29 soaps were most affected by Pseudomonas putida having their residual surfactant content and growth turbidity as 0.004 mg/ml (6.23± 0.0), 0.012 mg/ml (6.93±0.01) and 0.007mg/ml (7.0±0.0) respectively. Ariel and omo detergent were most affected by Exiguobacterium profundum having the same residual surfactant content and different 4 growth turbidity as 0.014 mg/ml (6.95 ± 0.0) and (6.85±0.0). In the fungal degradation, sunlight detergent and canoe soap were most affected by Trichoderma viridae having their residual surfactant content and growth turbidity as 0.021mg/ml (2.12±0.0) and 0.027mg/ml (2.44±0.03) respectively. The B29 soap and omo detergent were most affected by Penicillium italicum having their residual surfactant content as 0.027mg/ml (2.36±0.04) and 0.021mg/ml (2.64±0.0) respectively, while Ariel detergent was most affected by Varicosporum elodeae having its residual surfactant content as 0.025mg/ml and its growth turbidity as 3.0±0.01. The isolates were later subjected to alkylsulphatase enzyme assay to futher clarify the ability of the microbial isolates for enzymatic degradation of the detergents and soaps. Pseudomonas putida and Exiguobacterium profundum showed greater biodegrading potential amongst the isolates after quantifying the enzyme activity. They were subjected to molecular characterization to confirm their identity