PREVALENCE OF PETROLEUM DEGRADING BACTERIA IN CRUDE OIL POLLUTED INTERTIDAL MANGROVE SOIL

Complete Material Cost #3,000

Order for Complete Material now

ABSTRACT

The study evaluates the prevalence of petroleum degrading bacteria in crude oil intertidal mangrove soil. It was done using standard microbiological techniques. The results from the study showed that the bacteria Pseudomonas spp., Bacillus spp. and Staphylococcus aureus were present in soil samples contaminated with crude oil and also that these bacteria can survive in crude oil polluted environment. All the isolates were able to grow on crude oil as the sole carbon and energy source. However, they showed varying abilities in the degradation of the crude oil. The study revealed that Bacillus spp., Staphylococcus spp. and Pseudomonas spp., prevail in crude oil polluted intertidal mangrove soil. Bacteria isolated of this work can readily be applied to remedy an oil pollution problem in the environment.

 

CHAPTER ONE

INTRODUCTION

1.1   BACKGROUND OF THE STUDY

Crude oil is a complex mixture of hydrocarbons, composed of aliphatic, aromatic and asphaltene fractions along with nitrogen, sulfur and oxygen-containing compounds (Jain et al., 2005). Contamination of soils by oil spills is a persistent and widespread pollution problem ravaging almost all compartments of the environment and imposing serious health implication and ecological disturbances (Bundy et al., 2002; Okoh, 2006). Petroleum pollutants are not only toxic to biological component of the environment, but some hydrocarbon components are indeed carcinogenic and mutagenic, with immunomodulatory effects on humans, animals and plant life (Miller and Miller, 1981; Obayori et al., 2009). Hydrocarbon degrading bacteria and fungi are mainly responsible for the mineralization of oil pollutants and are distributed in diverse ecosystems (Leahy and Colwell, 1990). Different methods have been used in restoring petroleum polluted soil; some of these include the use of oil degrading microorganisms, inorganic fertilizers, chicken droppings, periwinkle shell, liming and tilling (Leahy and Colwell 1990; Ijah et al., 2003).

Currently, about 80% of lands and soil are contaminated/polluted by products of petroleum origin (hydrocarbons, solvents etc.) used as an energy source in the oil industry, as well as chemicals. There is a variety of pollutants affecting soil and subsoil, such as fuel and oil products, hydrocarbon residues, crude oil, and other products resulting from the operation, saturated and unsaturated aliphatic hydrocarbons, and the monocyclic and polycyclic aromatics (Marinescu et al., 2010).

The high demand for petroleum and associated products during the last ten decades has made petroleum spills inevitable consequences of oil production and refining. Despite fluctuations in its prices, oil will remain a major source of energy in the next several decades because a reliable alternative has not yet been found. As a result, the problem of pollution during production and transportation of oil would remain a major issue. Microbial degradation appears to be the most environmentally friendly method of removal of oil pollutant since other methods such as surfactant washing and incineration lead to introduction of more toxic compounds to the environment. Hydrocarbon-degrading microorganisms are widely distributed in marine, freshwater, and soil ecosystems (Atlas and Bartha, 1973). The ability to isolate high numbers of certain oil degrading microorganisms from an environment is commonly taken as evidence that those organisms are the active degraders of that environment (Okerentugba and Ezeronye, 2003). Although, hydrocarbon degraders may be expected to be readily isolated from a petroleum polluted environment, the same degree of expectation may be anticipated for microorganisms isolated from a total unrelated environment. There is an extensive body of knowledge on mineralization or degradation of hydrocarbons by microorganisms (Ojomu et al., 2005; Adenipekun and Fasidi, 2005).

Most of these organisms, majority of which are bacteria have been characterized and classified using cultural, biochemical and molecular techniques. Bacteria have evolved millions of years ago regulatory systems that ensure the synthesis of enzymes so that the initial attack on these compounds is induced only when required.

In a study, Ojo (2006) reported the capability of native bacterial population to mineralize petroleum hydrocarbons in wastewater. Similarly, Okoh (2003) demonstrated degradation rates of different strains of Pseudomonas aeruginosa on crude oil with evidence of significant reduction of major peak components of the oil. Bacillus, Enterobacter and Arthrobacter spp. are also reported to be present in soils contaminated with crude oil (Igwe, 2014).

Virtually all of these studies utilized organisms isolated from petroleum contaminated sites and degradation competencies were only tested on crude oil. In this report however, we chose to isolate hydrocarbon degraders from crude oil polluted intertidal mangrove soil. Degradation potentials of the obtained isolates were not only demonstrated on crude oil, and petroleum feedstocks including kerosene, and diesel but naphthalene which is usually less degradable compared to the petroleum fractions (Bola et al., 2006).

1.2   STATEMENT OF PROBLEM

Bodo is an oil rich community with huge environmental crude oil pollution. Microbiological studies on this environment have not been done and so it lacks information on the microbial state of the polluted environment. The conditions prevailing in the Bodo environment increase in pollution from crude oil. Hence, the evaluation of the prevalence of petroleum degrading bacteria in crude oil polluted intertidal mangrove soil.

1.3   AIM AND OBJECTIVES OF STUDY

The isolation of high numbers of certain microorganisms (bacteria) in an environment form evidence that those organisms are the active degraders of that environment.

This study therefore, intends to achieve the following objectives:

  1. To evaluate the prevalence of bacteria inhabiting oil impacted soil.
  2. To isolate indigenous bacteria capable of utilizing hydrocarbon from crude oil polluted soil.

1.4 SCOPE OF STUDY

This research work covers the isolation and identification of petroleum degrading bacteria from crude oil polluted mangrove intertidal soils. This was done through microbiological techniques.

1.5 SIGNIFICANCE OF THE STUDY

This study will isolate the bacteria associated with crude oil polluted mangrove intertidal soils. The results from this investigation would be useful for the prediction of the bacteria in crude oil polluted environments.

1.6 DEFINITION OF TERMS

CRUDE OIL

This is a naturally occurring, yellow to black liquid found I geological formations beneath the Earth’s surface, which is commonly refined into various types of fuels. Is consists of hydrocarbons of various molecular weights and other organic compounds.

POLLUTION

Pollution is the introduction of contaminants into natural environment that cause adverse change.

PETROLEUM DEGRADING BACTERIA

These are bacteria that use organic (carbon-containing) compounds as a source of energy and carbon.

INTERTIDAL SOILS

Intertidal soils are soils of the coastal shoreline covered by saltwater when the tide is high and exposed to the air when the tide is low.

 

Complete Material Cost #3,000

Order for Complete Material now

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *