Probiotic Potentials Of Lactic Acid Bacteria Isolated From Locally Fermented Maize (Akamu)

ABSTRACT

Lactic Acid Bacteria (LAB) as probiotic organisms can be sourced from fermented diary and vegetable products. The problem in Nigeria is their affordability to the greater populace, as the common sources are relatively expensive. The study was aimed at identifying the probiotic LAB and screening their probiotic activity involved in a low cost meal which is locally fermented maize (Akamu). This LAB predominates the microflora of fermented products. They produce metabolites that inhibit the growth of food borne pathogen and are beneficial to the GIT. Isolation and identification of LAB from fermented maize (akamu) was evaluated based on the biochemical characteristics and carbohydrate fermentative pattern. The four (4) isolates of lactic acid bacteria are Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus casie and Enterococcus faecium. The lactic acid bacteria (LAB) strains were tested for their probiotic activity against four test pathogens; Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Klebsiella species. Their resistance to acid and bile was determined. Their optimum antimicrobial activity was judged by their different zones of inhibition. There was significant differences between the samples at P<0.05. Lactobacillus plantarum was significantly higher at (21.67±0.58) for Salmonella followed by Lactobacillus acidophilus. The test LAB demonstrated efficient probiotic properties by inhibiting the test pathogens, tolerating acid at pH 3.0 and withstanding 0.3% bile concentration. The results revealed that akamu is a rich source of probiotic LAB and thus can be recommended as food.

TABLE OF CONTENTS

Title page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgement ﾿ iv

Table of contents ﾿ v

List of tables ﾿ vii

List of figures ﾿ viii

Abstract ﾿ ix

CHAPTER ONE

1.1 ﾿ Probiotics ﾿ 1

1.2 ﾿ Prebiotics ﾿ 2

1.3 ﾿ Synbiotics ﾿ 3

1.4 ﾿ Aim and Objectives of the study ﾿ 4 ﾿

CHAPTER TWO

2.0 ﾿ Literature Review ﾿ 5

2.1 ﾿ Lactic Acid Bacteria ﾿ 5 ﾿

2.2 ﾿ Lactobacillus bacteria ﾿ 6

2.3 ﾿ Enterococcus ﾿ 9

2.4 ﾿ Probiotic Potentials of Lactic Acid Bacteria Isolated from Locally 

Fermented Maize ﾿ 11

2.4.1 ﾿ pH and Organic Acid Production ﾿ 12

2.4.2 ﾿ Acid and Bile Tolerance ﾿ 13

2.4.3 ﾿ Stimulation of the Immune System ﾿ 14

2.4.4 ﾿ Adhesion to Intestine Mucus Layer and Epithahial Cells of Human GIT ﾿ 15

2.4.5 ﾿ Resistance of Antibiotics ﾿ 16

CHAPTER THREE

MATERIALS AND METHODS

3.1 ﾿ Collection of Akamu Samples ﾿ 17

3.2 ﾿ Test Organisms ﾿ 17

3.3 ﾿ Isolation of Lactic Acid Bacteria from Akamu ﾿ 17

3.4 ﾿ Identification of Laboratory Isolates ﾿ 18

3.4.1 ﾿ Gram Staining ﾿ 18

3.5 ﾿ Biochemical Test ﾿ 18

3.5.1 ﾿ Catalase Test ﾿ 18

3.5.2 ﾿ Oxidase Test ﾿ 19

3.6 ﾿ Sugar Utilization Test ﾿ 19

3.7 ﾿ Probiotic Activities of the Isolates ﾿ 19

3.7.1 ﾿ Antimicrobial Activities ﾿ 19

3.7.2 ﾿ Acid Tolerance ﾿ 20

3.7.3 ﾿ Bile Tolerance ﾿ 20

CHAPTER FOUR

Result ﾿ 22

CHAPTER FIVE

DISCUSSION AND CONCLUSION

5.1 ﾿ Discussion ﾿ 30

5.2 ﾿ Conclusion ﾿ 35

REFERENCES