Effects Of Carbon Source On The Antifungal Activities Of Some Isolated Actinomycetes.

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