ABSTRACT

This study was carried out to determine the effects of carbon source on the antifungal activities of some isolated species of Actinomycetes. Two (2) isolates of Actinomycetes and Streptomyces species were tested against two phytopathogens (Alternaria and Collectotrichum) On screening for its ability to enhance antifungal activity of actinomycetes, basal medium supplemented with glucose as a carbon source was found to be the best for antibiotic production by Actinomyces with the zone of inhibition of (17mm) against Alternaria and (21mm) against Collectrotrichum, this is followed by soluble starch with the zone of inhibition of (15mm) and (18mm) against Alternaria and Collectrotrichum, lactose (5mm and 4mm) and sucrose (2mm and 1mm) whereas fructose had repressed the production of the antimicrobial substance. Basal medium supplemented with soluble starch (12mm and 14mm) as a carbon source was found to be the best for antibiotic production by Streptomyces; this is followed by glucose (10mm and 11mm), lactose (5 and 6) and sucrose (4mm and 6mm) whereas no antimicrobial activity was detected using fructose. The results of this study showed that Actinomyces and Streptomyces species produces antifungal substances which are particularly active against the test organisms; Alternaria and Collectotrichum. Also, soluble starch and glucose were good carbon sources for optimal production of secondary metabolites. 

TABLE OF CONTENTS

Title Page   i

Certification ii

Dedication iii

Acknowledgement iv

Table of Contents v

List of Tables vii

Abstract viii

CHAPTER ONE

1.0 Introduction 1

1.1 Aims and Objectives 3

CHAPTER TWO

2.0 Literature Review 4

2.1 The Actinomycetes 4

2.2 Streptomyces 6

2.3 Classification of Streptomyces 7

2.4 The Life Cycle of Streptomyces 7

2.5 Streptomyces Habitats 8

2.5.1 Hay and other organic material 8

2.5.2 Fresh water and marine habitats 9

2.6 Streptomyces Requirements 9

2.7 Streptomyces Metabolites 10

2.8 Isolation of Streptomyces 10

2.9 importances of streptomyces 11

2.10 Streptomyces and antibiotics 12

2.11 Antibacterial activity of Streptomyces 14

2.11.1 Sampling 14

2.12 Nutrient Requirements for Antibiotic Production 14

2.13 Antibacterial Activity Protocols 16

2.13.1 Cross streak method 16

2.13.2 Agar overlay method 16

2.13.3 Disc Diffusion assay 16

2.13.4 Agar well diffusion assay 17

2.14 Factors Affecting Antibiotic Production 17

2.14.1 Carbon Source 17

2.14.2 Nitrogen source 18

2.14.3 Inorganic phosphate 18

2.14.4 Trace metals 19

CHAPTER THREE

3.0 Materials and Methods 20

3.1 Study Area 20

3.2 Sample Collection 20

3.3 Preparation of Culture Media 20

3.4 Sample Inoculation 21

3.5 Screening for Antimicrobial Activity Of The Isolates 21

CHAPTER FOUR

4.0 Result 23

CHAPTER FIVE

5.0 Discussion and Conclusion 26

5.1 Discussion 26

5.2 Conclusion 27

References 28

Appendix 36