Abstract

Biosurfactants are amphiphilic molecules that have both hydrophilic and hydrophobic moieties which partition preferentially at the interfaces such as liquid/liquid, gas/liquid or solid/liquid interfaces. Such characteristics enable emulsifying, foaming, detergency and dispersing properties. Their low toxicity and environmental friendly nature and the wide range of potential industrial applications in bioremediation, health care, oil and food processing industries makes them a highly sought after group of chemical compounds. Interest in them has also been encouraged because of the potential advantages they offer over their synthetic counterparts in many fields spanning environmental, food, biomedical, petrochemical and other industrial applications. Their large scale production and application however are currently restricted by the high cost of production and by the limited understanding of their interactions with cells and with the abiotic environment.

TABLE OF CONTENTS

Certification i

Dedication ii

Acknowledgement iii

Table of contents iv

List of Tables vii

List of Figures viii

List of Plates   ix 

Indent                         x

Abstract xi

CHAPTER ONE

INTRODUCTION

1.1 Background of the study 1

1.2 Statement of the Problem 3

1.3 Objective of the Study 3

CHAPTER TWO

LITERATURE REVIEW

2.1 Microorganisms producing biosurfactant 4

2.2 Applications Of Biosurfactant 7

2.3 Biosurfactant Production Substrates 8

2.3.1 Agro-industrial waste 9

2.3.2 Vegetable Oils and Oil Wastes 10

2.3.3 Olive Oil Mill Waste Effluents (OMWE) 11

2.3.4 Starchy substrates 12

2.3.5 Industrial waste from animals and plant origin 13

2.4 Influence of culture medium composition on Biosurfactant production 15

2.4.1 Carbon source 15

2.4.2 Nitrogen source 16

2.5 Environmental factors affecting the production of Biosurfactant 17

2.6 Classes of Biosurfactant 20

2.7 Properties of Biosurfactant 23

CHAPTER THREE

MATERIALS AND METHODS

3.1 Sample Collection 26

3.2 Preparation and Sterilization Of Media 26 

3.3 Isolation and Screening Of Bacterial Isolates 27

3.4 Morphological and Biochemical Characterization of Biosurfactant 

Producing Isolates 27 

CHAPTER FOUR

RESULTS

 4.1 Isolation And Screening Of Isolates for  Biosurfactant Production 32

4.2 Morphological And Biochemical Characterization Of Biosurfactant 

Producing Isolates 36

4.3 Degree of Occurrence of Biosurfactant Producing Microorganisms 38

CHAPTER FIVE

DISCUSSION, CONCLUSION AND RECOMMENDATION

5.1 Discussion 39

5.2 Conclusion 40

5.3 Recommendation 41

REFERENCES 42

LIST OF TABLES

Table     Title       Page

2.1 List of Biosurfactant producing organisms 4

3.1 Composition of Mineral Salt Medium(MSM) 26

4.1 Biosurfactant production by distinct isolates 32

4.2 Biochemical characterization of Biosurfactant producing isolates 38

4.3 Frequency of occurrence of Biosurfactant producing organisms 39

LIST OF FIGURES

Figure             Title             Page

2.1 Structure of glycolipids 20

2.2 Structure of mono and di rhamnolipid 18

2.3 Structure of Trehalose lipid 18

2.4 Structure of sl lactonized and acid form 19

2.5 Structure of aminolipopeptide and cyclic aminolipopeptide 20

LIST OF PLATES

Plate                                                        Title                                                    Page

1 Biosurfactant testing of isolates using drop collapse method 34

2 Culture plate showing physical characteristics of some isolates 35

APPENDIX

Appendix               Title Page

1 Cross section of flower samples used for this work 54

2          Vaginalis flower specie 55

3 Hibiscus flower 56