The isolation of biosurfactant producing bacteria in floral nectar

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