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

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

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

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

CHAPTER TWO

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

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

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

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

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

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

CHAPTER THREE

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

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

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

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

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

3.5Bacteriological 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

CHAPTER FOUR

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

CHAPTER FIVE

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

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

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

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

 LIST OF TABLES

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

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

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

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

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