African Journal of Biotechnology Vol. 5 (10), pp. 983-986, 16 May 2006   

ISSN 1684–5315 © 2006 Academic Journals        

Full Length Research Paper

Effect of organic nutrient on microbial utilization of hydrocarbons on crude oil contaminated soil

Ibekwe, V. I.¹, Ubochi, K. C.² and Ezeji, E. U.²*

¹Dept. of Ind. Microbiology, Federal University of Technology Owerri, Nigeria.

²Dept. of Biotechnology, Federal University of Technology Owerri, Nigeria.

*Corresponding authors E-mail: ucheezeji@yahoo.com, Phone; +234-8033-429-193.

Accepted 22 March, 2006

Abstract

The effect of organic nutrient (poultry manure) on biodegradation of soil (5 kg) contaminated with crude oil (50 g) was investigated for seven weeks. Four different test options were prepared namely; (i) 100 g of contaminated soil + 30 g of poultry manure; (ii) 100 g of contaminated soil + 60 g of poultry manure; (iii) 100 g of contaminated soil + 90 g of poultry manure; (iv) 100 g of contaminated soil only (control). The microbial degradation was monitored by the measurement of total heterotrophic count (THC), hydrocarbon utilizing bacterial count (HUB) and gravimetric loss of the crude oil with time. The cumulative THC of 6.9x10⁷, 9.0x10⁷, 1.03x10⁸ and 3.1x10⁷ cfu/g were recorded for test options (i), (ii), (iii) and (iv), respectively. The hydrocarbon utilizing bacterial counts (HUB) were 1.68x10⁵, 1.63x10⁵, 1.9x10⁵ and 4.8x10⁴ cfu/g for tests options (i), (ii), (iii) and (iv), respectively. There was a corresponding gravimetric hydrocarbon loss of 40.0, 45.26, 49.47 and 29.47% for test conditions (i), (ii), (iii), and (iv), respectively. The results of the study suggest that addition of organic nutrient (especially 90 g poultry manure) will further enhance microbial utilization of hydrocarbons.

Key words: Biodegradation, crude oil, poultry manure.