Volume 3 • Issue 2 • 1000116 J Pet Environ Biotechnol ISSN: 2157-7463 JPEB, an open access journal Open Access Research Article Petroleum & Environmental Biotechnology Nduka et al., J Pet Environ Biotechnol 2012, 3:2 http://dx.doi.org/10.4172/2157-7463.1000116 *Corresponding author: John Kanayochukwu Nduka, Environmental Chemistry and Toxicology Research Unit, Pure & Industrial Chemistry Department, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Anambra State, Nigeria, E-mail: johnnduka2000@yahoo.co.uk Received December 17, 2011; Accepted February 20, 2012; Published February 22, 2012 Citation: Nduka JK, Umeh LN, Okerulu IO, Umedum LN, Okoye HN (2012) Utilization of Different Microbes in Bioremediation of Hydrocarbon Contaminated Soils Stimulated With Inorganic and Organic Fertilizers. J Pet Environ Biotechnol 3:116. doi:10.4172/2157-7463.1000116 Copyright: © 2012 Nduka JK, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Different microbes (E.coli, Proteus, Klebsiella and Pseudomonas sp) were utilized in degradation of different hydrocarbon (Engine oil/diesel, kerosene and fuel) contaminated soils amended with inorganic (NPK and urea) and organic (cow dung and poultry litter) fertilizers and in some their combination. The incubation period ranged from 3 – 18 days. Bacterial population count and residual hydrocarbon were determined .Results showed that bacterial population count increased as the microbes utilized hydrocarbon for carbon and energy sources, the increase in population count and degradation of the hydrocarbons was stimulated by the fertilizer. It was also observed that as the population count increased due to hydrocarbon utilization for carbon and energy, residual hydrocarbon decreased and percentage degradation increased. Urea fertilizer was the best amendment for E.coli to degrade kerosene, NPK and cow dung differently aided the same E.coli in degrading engine oil. Pseudomonas and Proteus species degraded kerosene and fuel better in the presence of NPK fertilizer. Klebsiella specie degraded diesel and engine oil better when amended with poultry litter and cow dung respectively at least for the irst 9 days. More than 90% of the hydrocarbons were degraded within each incubation period. The microbes began to die as from the 15 th day of incubation, this may be due to secretion of toxic secondary metabolites. Control experiments revealed that there was initial increase in population count of the microbes as they utilized the hydrocarbon for carbon and energy, but they began to die because of non-stimulation with fertilizer, therefore less than 50% of the hydrocarbons were degraded in all the control experiments. Maize seeds grew on the remediated soil within six (6) days of planting. Utilization of Different Microbes in Bioremediation of Hydrocarbon Contaminated Soils Stimulated With Inorganic and Organic Fertilizers John Kanayochukwu Nduka*, Linda Nkechi Umeh, Isaac Obi Okerulu, Lilian Ngozi Umedum and Helen Nkechi Okoye Environmental Chemistry and Toxicology Research Unit, Pure & Industrial Chemistry Department, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Anambra State, Nigeria Keywords: Biodegradation; Bioremediation; Microbes; Hydrocarbon; Fertilizer; Contaminated soil Introduction he world, in which we live as it is today, is the world in which everything we do as regards human growth, biological, physical, economic, industrial and infrastructural growth, science and technological growth etc. revolves around energy. Apart from the traditional irewood, wind and hydro power, petroleum hydrocarbon continues to be used as the most principal and versatile source of energy and therefore an important global environmental pollutant [1]. Crude oil or petroleum hydrocarbon exploration and exploitation which came ater industrial revolution stems from advances in science and technology which have enabled humans to exploit their natural resources, although not without a cost, as it has generated unprecedented disturbances in global elemental cycles [2]. he relatively sudden introduction of xenobiotic chemicals as well as the massive relocation of natural materials to diferent environmental compartments can oten overwhelm the self cleaning capacity of recipient ecosystems and therefore result in the accumulation of pollutants to problematic or even harmful levels [3]. Bioremediation plays a great role in solving some of these problems. Bioremediation is the application of biological treatment to clean up hazardous chemicals. his process involves detoxiication where the pollutant may be converted to less toxic substances and mineralization, where the waste material can be converted into inorganic compounds such as carbon dioxide, water, methane and sometimes fatty acids [4]. Bioremediation is not new to human race but new approaches that stem from advances in molecular biology and process engineering are emerging. Microbes bioremediate the environment as they biodegrade the pollutant to obtain carbon and energy, Biodegradation speciically refers to chemical breakdown or mineralization of materials facilitated by biological organisms or products [5]. Contamination of the environment with petroleum hydrocarbons has caused critical health defects and therefore increasing attention has been focused on developing and implementing innovative technology for cleaning up this contamination [3,6]. When oil spillages occur as with the cases in the Niger-delta region of Nigeria , concerted eforts are made to remove, remediate or recover the spilled oil immediately, but when the spill is small as in automobile workshops, gasoline petrol station, and during tanker, loading or of-loading operations at the reinery or during clean-up operations, the possible efect is that it may be ignored, but on continuous and prolonged spill as the case has been, contamination of ground water and air due to evaporation is possible because of its persistence. Bioremediation methods therefore come in handy and have correctly received favorable publicity as promising environmentally friendly technique for the remediation of hydrocarbon contaminated ecosystem [7]. his is possible because microorganisms have enzyme system to degrade and utilize diferent hydrocarbon as a source of carbon and energy [8]. A number of gram positive and negative microbes have been reported to be capable of utilizing a wide variety of hydrocarbons as carbon and energy [9]. he microorganisms include bacteria of the genera Klebsiella, Proteus, Bacillus, Escherichia, Pseudomonas, Streptomyces, Nocardia, Seratia, Xanthomonas, Micrococcus etc. and