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African Journal of Biotechnology

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Evaluation of soil microbial communities as influenced by crude oil pollution

EO Nwaichi, M Frac

Abstract


Impact of petroleum pollution in a vulnerable Niger Delta ecosystem was investigated to assess interactions in a first-generation phytoremediation site of a crude oil freshly-spilled agricultural soil. Community-level approach for assessing patterns of sole carbon-source utilization by mixed microbial samples was employed to differentiate spatial and temporal changes in the soil microbial communities. Genetic diversity and phenotypic expressions were measured for a more holistic perspective. The 5’-
terminal restriction fragments generated after Csp digestion of 16S rRNA gene correlated with observed DNA concentrations in the community profile and revealed loss of diversity with pollution. Crude oil pollution significantly reduced phosphomonoesterases and respiratory activities and values were pH dependent. There were no expressed dehydrogenases activity in initial spill site but were enhanced with phytoremediation. Factor analysis of predictors and independent variables indicates that respiratory, alkaline phosphatase and â-glucosidase activities could be used to explain underlying factors. Positive soil – microbes - plant interactions were observed.


Key words: Species diversity, impact of crude oil pollution, soil – biota interactions, ecosystem monitoring, genetic diversity.




AJOL African Journals Online