EFFECTS OF SIMULATED CRUDE OIL CONTAMINATION ON THE PHYSICOCHEMICAL PROPERTIES AND BACTERIAL POPULATION OF RHIZOSPHERE OF SORGHUM VULGARE PERS, A RESEARCH PROJECT TOPIC ON PLANT SCIENCE
ABSTRACT
This study has been undertaken to investigate the physicochemical properties and the bacterial population of the rhizosphere of Sorghum vulgare. In order to simulate spillage, 0.2, 0.9 and 5.0 v/w concentrations of crude oil were used to contaminate soil sown with seeds of Sorghum vulgare, while the control had no crude oil contamination. One hundred and twenty days after contamination, the physicochemical properties and bacterial population of the rhizosphere were analyzed using standard techniques. Results showed that 5.0 % v/w of crude oil used in this study caused significant (P<0 .05=”” 0.05=”” 0.9=”” 5.0=”” a=”” all=”” and=”” as=”” bases=”” been=”” bulk=”” cations=”” compared=”” concentration=”” conditions=”” conductivity=”” content=”” could=”” crude=”” density=”” electrical=”” exchangeable=”” fertility=”” gave=”” have=”” highest=”” hydrocarbon=”” in=”” increase=”” low=”” matter=”” may=”” moisture=”” na=”” of=”” oil=”” organic=”” other=”” particle=”” petroleum=”” ph=”” physicochemical=”” pollution.=”” reduced=”” result=”” sand=”” significantly=”” silt=”” simulate=”” soil=”” span=”” such=”” suggest=”” temperature=”” the=”” these=”” to=”” total=”” treated=”” treatments.=”” used=”” v=”” w=”” were=”” when=”” while=”” with=””>+, Ca2+, Mg2+ and K+, total nitrogen and bacterial population when compared with all the other treatments and significant decrease in total petroleum hydrocarbon when compared with all the crude oil treated samples. This suggests that there was synergistic cooperation between roots of Sorghum vulgare and rhizospheric bacteria which may have facilitated removal of petroleum hydrocarbon and improved the physicochemical conditions and bacterial population of the soil treated with 0.9 % v/w concentration of crude oil. Hydrocarbon-utilizing bacteria isolated from the crude oil contaminated rhizosphere of Sorghum vulgare were Pseudomonas sp., Bacillus sp., Klebsiellasp. and Streptomyces sp.
CHAPTER ONE
1.0Â Â Â Â Â INTRODUCTION
The inevitable and disastrous consequence of crude oil pollution for the biotic and abiotic components of the ecosystem has been a major source of concern to the government and people living in oil producing and industrialized countries. This had led to ethnic and regional crises in the Niger Delta region that generated significant tension between them and the multinational oil companies operating in the region (Vidal, 2010).Crude oil exploration, production and transportation in the Niger Delta region have increased tremendously since its discovery in Nigeria in 1956 and has become a veritable source of economic growth and the main stay of the Nigerian economy (Okoh, 2006).The global scale of oil production is staggering and its demand is in the order of 3.25 x 109Â tones or 3.8 x 1012Â liters per year and much of it is transported thousands of kilometers before it is used (Prince and Lessard, 2004).
