ABSTRACT

This study was carried out to find the antimicrobial effects of soil microorganisms that have the potential to produce antibiotics. Ten soil samples were collected from four different (Rhizosphere, Waterlog, Back of COLNAS, Forest soil) sites of Umudike. The isolated strains were obtained by ten-fold serial dilution method plated on Sabrouraud Dextrose agar and Nutrient agar by spread plate method. These were then assessed for antibacterial activity against four pathogenic bacteria. Twenty six isolates were recovered and four showed evidence of antibiotic. However, result indicated that three out of the four that showed evidence of antibiotic were active against at least one of the test organisms, Escherichia coli (ATCC 25922),Staphylococcus aureus (ATCC25923), Pseudomonas aeruginosa (ATCC 27853),Mycobacterium smegmatis (ATCC 28735).S1A2 and S3A19 exhibited high antibacterial activity against Staphylococcus aureus, S4A24 showed slight zone of inhibition against Pseudomonas aeruginosa, while S2A15 shown no clear zone of inhibition against test organisms. Therefore, it is confirmed that soil samples screened for microorganisms producing antibiotic collected within the University premises of Umudike were found to be potential source of novel antibiotics.

TABLE OF CONTENTS

Title page ii

Certification iii

Dedication iv

Acknowledgements v

Table of contents vi 

List of Tables viii

Abstract ix

CHAPTER ONE

1.0 INTRODUCTION 1

1.1 Antibiotics 2

1.2 Aims and Objectives 4

CHAPTER TWO

2.0 LITERATURE REVIEW 5

2.1  Occurences of Antibiotic producing Bacteria from Soils 6

2.2 Factors Considering in Selection of Antibiotics 9

2.3  Antibiotics and its Classification 9

2.4  Physiology of Antibiotic Production 11

2.5 Factors affecting Antibiotic Production 11

2.6 Fermentation Conditions 13

2.7  Biology and Pathogenicity of some Test Organisms 15

CHAPTER THREE

MATERIALS AND METHODS

3.1  Collection of Soil Samples 18

3.2 Media Used 18

3.3 Media Preparation 18

3.4 Collection of Test Organisms 18

3,5 Sample Preparation 19

3.6 Sub culturing 19

3.7 Gram Staining 19

3.8 Biochemical Identification of Bacterial Isolates ` 20

3.9 Biochemical Tests 20

3.10 Confirmation of Antibacterial Activity

CHAPTER FOUR

RESULTS 23

CHAPTER FIVE

 DISCUSSION 28

Conclusion 30

References 31

LIST OF TABLES

TABLES TITLE PAGES   

 1;          Description of Samples collected from different sites in 

Michael Okpara University of Agriculture,Umudike. 24

 2;          Description of Samples collected from different sites in Umudike, and isolate actinomycetes. 25

 3;          Morphology, and Biochemical Characterization of the 

Bacterial Isolates 26

 4;                   Inhibition of test organisms by  bacterial isolates 2