Browsing by Author "Wanjala , Muyoma Paul"

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    Characterization of culturable microbial community in oil contaminated soils in Greater Port Harcourt Area, Nigeria
    (Academic Journals, 2020-09-17) Wanjala , Muyoma Paul
    The study investigated microbial population dynamics in soils of Greater Port Harcourt Area, Nigeria. The study involved the quantification of petroleum pollutants and the enumeration and characterization of culturable fungi and bacteria. Gas Chromatograph FID method was used to quantify total petroleum hydrocarbons (TPH) in the soil while morphological and biochemical tests were used to characterize the microorganisms. The highest TPH was 9,759.37±883.36 ppm which exceeded the Department of Petroleum Resources’ (DPRs’) intervention value of 5,000 ppm. The percentage of hydrocarbon utilizing fungi (% HUF) ranged between 1.93±0.57 and 66.55±5.60 which were observed in sites A1 (Aluu) and CA (Agricultural control), respectively. The percentage of hydrocarbon utilizing bacteria (% HUB) ranged between 0.12±0.01 and 7.89±1.25 which was observed in sites A3 (Emuoha) and CU (Urban control), respectively. The most prevalent bacterial species includes Bacillus subtilis, Micrococcus lylae, Staphylococcus aureus, Bacillus cereus and Alcaligen faecalis. The most prevalent HUB isolate was Bacillus subtilis. The most prevalent fungal isolates were Aspergillus niger, Aspergillus flavus and Candida torulopsis. A. niger was the most prevalent among the HUF isolates which was identified in 12 sites. It was concluded that the study sites harboured TPH degrading microorganisms that are appropriate for bioremediation of TPH polluted sites.
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    Impact of Nitrogen Fertilizer Use on Soil Ecosystem Integrity in the Greater Port Harcourt Region, Nigeria
    (Science Publishing Group, 2021-10-05) Wanjala , Muyoma Paul
    Fertilizers are used to increase crop yields in agriculture but can affect the integrity of soil ecosystems if misused. The present study was conducted to observe the impact of inorganic fertilizers in selected soils in Greater Port Harcourt Area on soil microbial population, in addition, the association between soil microbial population and Lethal Concentration 50 (LC50) was observed. Microbial communities and LC50 values were determined using normal analytical procedures. The study showed various fertilizer types that altered soil microbial population and LC50 values. For agricultural areas the maximum NPKB mean value was 0.70±0.76 ppm which was higher than the mean value of the control location of 0.23±0.00 ppm. Urea tolerant fungi’s (UREAF's) LC50 mean value was 0.43±0.09 ppm in the agricultural area as compared to the control with a mean value of 0.46±0.00 ppm. Industrial and urban areas had significantly different mean values of 0.29 ± 0.19 ppm and 0.18±0.01 ppm and 0.23 ± 0.06 ppm and 0.23 ± 0.060.17 ± 0.010.17 ± 0.010.17 ± 0.01 ppm respectively (p = 0.001). This research concluded that the application of UREA and NPK fertilizers in study area soils lowered the pH of soils in A1, A2 and A3 agricultural sites. Application of UREA and NPK fertilizers in soils of the study areas increased the population of microorganisms in threshold concentrations but was detrimental for NPK and UREA fertilizers at concentrations of 1.50% or above. Further findings showed that microorganisms were more tolerant of NPK and UREA fertilizers in agricultural areas compared to urban and industrial areas which showed higher LC50 values. This research concludes that fertilizers used in the study areas were related to soil microorganisms developing tolerance to NPK and UREA. Farmers should observe application of the recommended professional quantities of fertilizers to ensure the sustenance of the soil ecosystem integrity.