SCREENING, ISOLATION, AND CHARACTERIZATION OF ANTIBIOTIC PRODUCING MICROORGANISMS FROM SOIL SAMPLES IN MICHAEL OKPARA UNIVERSITY OF AGRICULTURE, UMUDIKE ABIA STATE

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