1. To isolate, characterize and identify antibiotic producing microorganisms from the Soil collected from farmlands in Michael Okpara University of agriculture, Umudike, Abia State

ABSTRACT

Antibiotics are one of the most important commercially exploited secondary metabolites produced by microorganisms. Most of the antibiotics used today are from microbes. In this present project work, soil microorganisms were isolated and screened for antibiotic production. The media used in this research study were Nutrient agar, Tryptone Soya agar and Sabouraud Dextrose agar. One gram (1g) of each of the soil samples was serially diluted in sterile normal saline to make soil suspensions. An aliquot of 0.1ml of the suspensions was innoculated on the medium by spread plate method. The inoculated plates were incubated at 35oC for 24 hours. After which the morphological and biochemical properties of the colonies were observed. A total of 57 isolates were obtained from the samples. The inhibitory activities of the isolates were investigated against some important pathogenic bacteria like; Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Enterococcus  faecalis ATCC 7080. Out of the 57 isolates obtained, 2 isolates were found to exhibit antibacterial activity against the test organisms. Although the identification of these isolates were not done up to species level, their morphological and biochemical characteristics indicate that they belong to the genus Bacillus.

TABLE OF CONTENTS

CERTIFICATION                                                                                              ﾿ i

DEDICATION                                                                                                    ﾿ ii

ACKNOWLEDGEMENTS                                                                                ﾿ iii

TABLE OF CONTENTS ﾿ iv

LIST OF TABLES                                                                                              ﾿ vi

ABSTRACT                                                                                                        ﾿ vii

CHAPTER ONE

1.0 ﾿ INTRODUCTION ﾿ 1

1.1Aims and objectives ﾿ 2 ﾿

CHAPTER TWO

2.0 ﾿ LITERATURE-REVIEW ﾿ 3

2.1Soil microbial interactions ﾿ 5

2.2 Types of microorganisms found in the soil ﾿ 6

2.2.1 Actinomycetes ﾿ 6

2.2.2 Fungi ﾿ 7

2.2.3 Algae ﾿ 7

2.2.4 Protozoa ﾿ 8

2.2.5 Some bacteria that produce antibiotics ﾿ 8

2.3. Factors affecting antibiotic production, activity and detection ﾿ 9        

2.3.1 Extraction from soil or plant material: physical and chemical considerations ﾿ 10

2.3.2 Sample collection and preparation ﾿ 11

CHAPTER THREE

MATERIALS AND METHODS

3.0 ﾿ Collection of samples ﾿ 12

3.1 Media preparation ﾿ 12

3.2 Isolation of microorganism from soil samples ﾿ 12

3.3Subculturing ﾿ 13

3.4 Characterization and identification of isolates ﾿ 13

3.4.1Colonial examination ﾿ 13

3.4.2Gram staining ﾿ 13

3.4.3Biochemical tests ﾿ 14

3.4.3.1Starch hydrolysis test ﾿ 14

3.4.3.2 Hydrogen sulfide ﾿ 14

3.5 Determination of antimicrobial activity ﾿ 14

CHAPTER FOUR

RESULTS ﾿ 17

CHAPTER FIVE

DISCUSSION, CONCLUSION AND RECOMMENDATION

5.0 ﾿ Discussion ﾿ 21

5.1 ﾿ Conclusion ﾿ 22

5.2 ﾿ Recommendation ﾿ 22

REFERENCES

LIST OF TABLES

Table                               Title                                                             Page

1:     Description of soil sample location ﾿ 18

2:     Morphology and biochemical properties of isolates ﾿ 19

3:     Antibiotic activity of bacterial isolates ﾿ 20