ABSTRACT

This study was carried to with the aim of determining the antibacterial effect of Calotropis procera against some bacteria isolated spoilt nunu. Bacteria isolated from spoilt nunu were identified based on their Gram characteristics, morphology and biochemical characteristics. Calotropis procera was extracted using ethanol, methanol and distilled water. The ethanol and methanol extracts showed the presence of Saponins, Steroids, Terpenoids, Flavonoids, Tannins, Alkaloids, and Cardiac glycosides. The aqueous extract showed the presence of Saponins, flavonoids, tannins, and alkaloids. The antibacterial analysis was determined using agar well diffusion assay. The bacteria isolated were identified as Escherichia coli, Staphylococcus aureus and Salmonella spp. The ethanol extract against E. coli ranged from 10 mm to 16 mm; the zone diameter of inhibition of the ethanol extract against S. aureus ranged from 12 mm to 22 mm; and 10mm to 18 mm against Salmonella spp. The methanol extract effect on E. coli ranged from10 mm to 19 mm; while on S. aureus the zone ranged from 10 mm to 20 mm and 12 mm to 21 mm against Salmonella spp. The aqueous extract showed zone of inhibition against E coli ranging from 9 mm to 15 mm; 8 mm to 18 mm against S. aureus and 8 mm to 14 mm against Salmonella spp.

TABLE OF CONTENT

Title page

Dedication----------------------------------------------------ii

Declaration--------------------------------------------------iii

Certification-------------------------------------------------iv

Acknowledgement---------------------------------------v

Abstract-------------------------------------------------------vi

Table of content------------------------------------------vii

CHAPTER ONE

1.0 Introduction-------------------------------------------1

1.1 Significance of the Study----------------------4

1.2 Aims and Objectives of the Study---------4

CHAPTER TWO

2.0 Literature Review-----------------------------------6

2.1 Economic Importance of Calotropis procera---------------------------------------------------------8

2.2 Latex Composition and Health Implication of Calotropis procera-----------------9

2.3 Health Implication of Calotropis procera Extract--------------------------------------------------------10

2.4 Lactic Acid Bacteria (LAB): Classification, Characteristics and Properties---------------------------------------------------11

2.5 Cellular Metabolism and Fermentation----------------------------------------------------------------------16

CHAPTER THREE

3.0 Materials and Method-------------------------21

3.1 Study Area------------------------------------------21 

3.2 Collection of Plant Material-----------------21

3.3 Sample Collection-------------------------------22

3.4 Media and Sterilization-----------------------22

3.5 Bacteriological Analysis of Spoilt Nunu---------------------------------------------------------------------22

3.5.1 Isolation--------------------------------------------22

3.5.2 Characteristics of Isolates----------------23

3.5.2.1Gram Staining----------------------------------23

3.5.2.2 Motility Test------------------------------------23

3.5.2.3 Catalase Test----------------------------------23

3.5.2.4 Sugar Fermentation------------------------24

3.5.2.5 Citrate Utilization----------------------------24

3.5.2.6 Indole Test--------------------------------------25

3.5.2.7 Methyl Red Test------------------------------25

3.6 Extraction of Plant Material----------------25

3.7 Phytochemical Screening-------------------26

3.7.1 Test for Saponins-------------------------26

3.7.2 Test for Steroids--------------------------26

3.7.3 Test for Terpenoids----------------------27

3.7.4 Test for Flavonoids----------------------27

3.7.5 Test for Tannins---------------------------27

3.7.6 Test for Alkaloids-------------------------27

3.7.7 Test for Free Anthraquinones Derivatives-------------------------------------------------28 

3.7.8 Test for Cardiac Glycosides--------------------------------------------------------------------------------28

3.8 Antibacterial Analysis of Plant Extract-----------------------------------------------------------------------28

3.8.1 Preparation of Test Inoculum------------28

3.8.2 Antimicrobial Assay---------------------29

3.8.3 Minimum Inhibitory Concentration (MIC) ----------------------------------------------------------29

3.8.4 Minimum Bactericidal Concentration (MBC) --------------------------------------------------------30

3.9 Statistical Analysis------------------------------30

CHAPTER FOUR

4.0 Results------------------------------------------------31

CHAPTER FIVE

5.0 Discussion------------------------------------------41

5.1 Conclusion------------------------------------------43

5.2 Recommendation--------------------------------43

REFERENCES----------------------------------------------44

 LIST OF TABLES

Table 1 Biochemical Characterization of Bacterial Isolates----------------------------------------32

Table 2 Phytochemical Analysis of Constituents-----------------------------------------------34

Table 3 Antibacterial Analysis of Calotropis procera Extracts----------------------------------------36

Table 4 Minimum Inhibitory Concentration of Calotropis procera Extracts-------------------38

Table 5 Minimum Bactericidal Concentration of Calotropis procera Extracts------------------------------------------------------40