ABSTRACT

Isolation and identification of antibiotic producing bacteria from soil were carried out. Ten (10) soil samples were collected from different sites around the institution and screened for potential antibiotic producing bacteria. The samples collected were analyzed for total heterotrophic bacteria and coliform count. The result showed that total heterotrophic count ranged from 2.0 × 104 cfu/g – 12 × 102 cfu/g and coliform count ranged from 1.4 × 102 cfu/g – 8.5 × 102 cfu/g. The bacteria isolated were Bacillus species, Micrococcus species, Pseudomonas species Staphylococcus species Streptococcus species Proteus species and Escherichia coli. Staphylococcus aureus, Bacillus species, Proteus species and Micrococcus species showed heavy growth as all the organisms grow in the media at different rates.  Bacillus species showed evidence of antibiotic production by inhibiting the growth of the test organisms such as Staphylococcus aureus (zone of inhibition 10mm), Escherichia coli (zone of inhibition 11mm), Pseudomonas species (zone of inhibition 3mm) and Streptococcus species (zone of inhibition 5mm). Moreover, the production of potential antibiotics as seen in this preliminary work was not recovered in large quantity around the university.

TABLE OF CONTENTS

Title Page

Certificate

Dedication                                                                                                  iii

Acknowledge

Table of Contents

List of Tables           

Abstract CHAPTER ONE: INTRODUCTION 1      1.1      STATEMENT OF PROBLEM 3 1.2 JUSTIFICATION                                               3         1.3       AIMS AND OBJECTIVES 5  

CHAPTER TWO: LITERATURE REVIEW 6

2.1       MICROORGANISMS AS SOURCES OF NATURAL PRODUCTS 7

2.1.1 ENZYME PRODUCTION 7

2.1.2 ANTIBIOTIC PRODUCTION 8

2.2 SOURCES OF ANTIBIOTIC PRODUCING MICROORGANISMS 9

2.3 CLASSIFICATION AND NOMENCLATURE OF ANTIBIOTICS 9

2.4 ANTIBIOTIC DIVERSITY 15

2.5 CONCEPT OF INDUSTRIAL RESEARCH IN ANTIBIOTIC PRODUCTION 15

2.6 PROGRESS OF TRENDS IN ANTIBIOTIC RESEARCH 17

2.7 GOALS OF ANTIBIOTIC RESEARCH 17

2.8 FACTORS CONSIDERED IN SELECTION OF ANTIBIOTIC 18

2.9 FACTORS AFFECTING ANTIBIOTIC PRODUCTION 19

2.10 BIOCHEMISTRY OF ANTIBIOTIC PRODUCTION 20

2.11 MECHANISMS OF ANTIMICROBIAL ACTION 22

2.12 SPECTRA OF ANTIMICROBIAL ACTIVITY 26

2.13 SCREENING METHODS

2.14 PRIMARY TESTING OF ANTIBIOTIC PRODUCTION 28

2.15 MICROBIAL DIVERSITY IN SOIL

CHAPTER THREE: MATERIALS AND METHODS

3.1 COLLECTION OF SOIL SAMPLE

3.2 PREPARATION AND STERILIZATION 31

3.3 SAMPLE PREPARATION AND INOCULATION 32

3.4 COLONIAL MORPHOLOGY 32

3.4.1 SUBCULTURING

3.4.2 GRAM STAINING

3.5 BIOCHEMICAL TESTS

35.1 CATALASE TEST

3.5.2 COAGULASE TEST

3.5.3 CITRATE UTILIZATION TEST 34

3.5.4 INDOLE TEST

3.5.5 OXIDASE TEST

3.5.6 UREASE TEST

3.5.7 STARCH HYDROLYSIS

CHAPTER FOUR: RESULTS 36

CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATIONS

5.1 DISCUSSION

5.2 CONCLUSION

             REFERENCES

LIST OF TABLES

Table         Title    Pages

1        The thirteen named groups of antibiotics based chemical structure        12

2        Microorganisms producing various antibiotics        13

3         Mean Colony Count (cfu/g)        37

4                Bacteria isolates and their percentage occurrence                   38

5                Zone of inhibition diameter (mm) of bacterial isolates against test organisms