ABSTRACT

The microbiological and physiochemical qualities of the soil contaminated with diesel were also analyzed; the total heterotrophic bacterial and fungal counts ranged from 1.1x105 cfulg to 6.1 x105 cfulg and 1.8 x103 cfulg to 7.2 x103 cfu/g respectively. The bacterial isolates were Staphylococcus species, Bacillus species, Streptococcus species Micrococcus species, Acinetobacter species, Pseudomonas aeroginosa, Escherichia coli, Klebsiella species, Arthrobacter, Citrobacter species. Fungi isolated include Aspergillus species, Mucor species, Geotrichum species, Rhizopus species and Fusarium species.  The values of the physiochemical parameters ranged as follows; total organic carbon 12.20% to 24.40%; total petroleum hydrocarbon, sulphate, nitrates and phosphate and ranged from 90mg/kg to 1650mg/kg, 75mg/kg to 1450mg/kg, 7.50mg/kg – 21.56mg/kg, 2.05mg/kg to 6.0mg/kg and 1.20mg/kg to 3.62mg/kg respectively. These changes brought by diesel contamination resulted in the reduction of pH and microbial biomass. 

TABLE OF CONTENTS

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Table of Contents v

List of Tables viii

Abstract ix

CHAPTER ONE: INTRODUCTION 1

1.1 Objective of the study 2

I.2 Limitation of the study 2

CHAPTER TWO: LITERATURE REVIEW

2.1 Soils 3

2.2 Basic branches of soil sciences 4 

2.2.1 Edaphology 4

2.2.3 Pedology 4

2.3 Physio-chemical properties of soil 4

2.3.1 Soil physical properties 4

2.3.1.1 Soil texture 5

2.3.2.1 Soil structure 5

2.3.2.2 Soil porosity 6

2.4 Soil chemical properties 7

2.4.1 Exchange capacity      7

2.4.1.1 Soil pH 7

2.4.1.2 Salt affected soils 8

2.4.1.3 Electrical conductivity 8

2.5 Organism associated with soil contaminated with diesel  9

2.5.1 Bacterial isolates 9

2.5.1.1   Staphylococcus species 9

2.5.1.2   Bacillus species 10

2.5.1.3   Micrococcus species 10

2.5.1.4   Streptococcus species 11

2.5.1.4   Corynebacterium 11

2.5.2 Acinetobacter species 11

2.5.2.1 Arthrobacter 12

2.5.2.2 Escherichia coli 12

2.5.2.3 Klebsiella species 12

2.5.2.4 Pseudomonas aeruginosa 13

2.6 Fungal isolates 13

2.6.1 Aspergillus species 13

2.6.2 Rhizopus species 13

2.6.2.1 Fusarium species 14

2.6.2.2 Mucor species 14

2.6.2.3 Geotrichum species 14

2.6.3 Bioremediation of Soils Contaminated with Diesel 14

CHAPER THREE: MATERIALS AND METHODS

3.1 Environment of study 16

3.2 Sample collection 16

3.3 Sterility of glass wares 16

3.3.1 Preparation of media 17

3.3.1.1 Enumeration of fungi and bacteria  17

3.3.2 Identification and characteristics of isolates 17

3.3.2.1 Cultural Examination 18

3.3.2.2 Microscope Examination 18

3.3.2.3 Gram Staining 18

3.3.2.4 Lactophenol Cotton Blue Stain 19

3.3.2.5 Test for Motility (Stab-culture technique) 19

3.4 Biochemical tests 19

3.4.1 Catalase production tests 19

3.4.1.1 Oxidase Test 20

3.4.1.2 Urease Test 20

3.4.1.3 Citrate Utilization Test 20

3.4.1.4 Voges-Proskaurer Test 21

3.5 Indole test 21

3.5.1  Sugar Fermentation Test 22

3.5.1.1 Coagulase Test 23

3.5.1.2 Methyl-Red (MR) Test 23

3.6 Determination of the physicochemical parameters 24

3.6.1 Determination of pH 24

3.6.2 Determination of Electrical Conductivity 24

3.6.2 Determination of Sulphates, Nitrates and Phosphates 24

3.6.3 Determination of Exchangeable Cations 24

3.6.4 Determination of Oil and Grease and Total Petroleum Hydrocarbon (TPN) 25

CHAPTER FOUR: RESULTS 26

CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATIONS

5.1 Discussion 34

5.2 Recommendations 35

5.3 Conclusion 35

REFERENCES 36

Appendix 41

LIST OF TABLES 

Table Title Page 

1: Mean count of microorganisms isolated from the soil samples (cfu/g) 28

2: Bacterial isolates and their percentage occurrence 29

3: Fungal isolates and their percentage occurrence 30

4: The value of the physiochemical parameter of the contaminated and 31

control soil Samples

5: Biochemical characterization of Bacteria Isolates 38

6: Isolation and Identification of fungi isolates from soil contaminated 39

with diesel