ABSTRACT

Antibiotics have substantially reduced the threat of infectious diseases. In the present study, twenty (20) soil samples were collected from the farm land behind Centre for Molecular Biosciences and Biotechnology (CMBB) in  Michael Okpara University of Agriculture Umudike (MOUAU). Streptomyces spp. and Bacillus spp. were isolated using Tryptone Soy Agar (T.S.A), Nutrient Agar (N.A), Sabouraud dextrose agar (S.D.A). A total of 50 isolates were gotten. These organisms were screened with regard to their antibacterial potential against different test organisms. The antibacterial activity of the isolates was tested using the disk diffusion method on a spread plate of the test organism (Staphylococcus aureus ATCC 2593TM, Pseudomonas aeruginosa ATCC 27853TM, Eschericha coli ATCC 25922TM, Enterococcus fecalis ATCC 7080TM). Five (5) isolates (10%) (A3, L2, C3, D1, J4) showed positive antibacterial activity. The positive isolates were further characterized based on their gram status and biochemical tests which include starch Hydrolysis, Hydrogen sulphide test, Catalase test. Some fungal spp which were isolated did not show any positive antibacterial activity and were not further characterized. The result obtained from this study, provides some information that would be useful to pharmaceutical industries that may be interested in the local production of antibiotics using locally isolated stains of microorganisms.

TABLE OF CONTENTS

Title Page i

Certification  ii

Dedication iii

Acknowledgements iv

Table of contents v

List of Tables vii

Abstract  x

CHAPTER ONE

1.0 INTRODUCTION 1

1.1 Aims and Objectives 3

CHAPTER TWO

2.0 LITERATURE REVIEW 4

2.1      Brief Overview of Antibiotic Isolation 8

2.2      Increasing Antibiotic Yield and Recovery 9

2.3      Natural Habitat of Antibiotic Producing Microorganisms 11

2.4      Factors Affecting Antibiotic Production and Activity 11

2.5      Isolation of Antibiotics from Microbial Biomass 12

CHAPTER THREE

MATERIALS AND METHODS

3.1      Collection of Soil Samples 14

3.2      Isolation and Enumeration of Microbes from Soil 14

3.3      Identification of Isolates 15

3.4      Gram Reaction 15

3.5      Biochemical Characterization 15

3.5.1 Starch Hydrolysis 15

3.5.2 Hydrogen Sulphide (H2S) Production Test 16

3.5.3   Catalase Test 16

3.6      Test Microorganisms 16

3.7 Antibiotic Sensitivity Test 17

CHAPTER FOUR

4.1      RESULTS 18

CHAPTER FIVE

DISCUSSION, CONCLUSION AND RECOMMENDATION

5.1 Discussion 23

5.2      Conclusion 25

5.3      Recommendations 25

REFERENCES

LIST OF TABLES

Table Title Page

1  Soil Samples with their total bacterial and fungal counts 19

2 Sample site and number of bacterial and fungal isolate 20

3 Colonial Morphology and biochemical test of isolate 21

4 Antibacterial Screening of isolates against test organisms with 

their zone(s) of Inhibition in (mm) 22