ABSTRACT

Thiamine, riboflavin and niacin are among the essential vitamins required for normal physiological function that cannot be synthesized by the body, and thus must be obtained from dietary source.  Five lactic acid bacteria were isolated from selected Nigerian fermented foods (Yoghurt, ogi, ogiri, ugba). The isolates were identified based on cultural and biochemical characteristics. All the isolates were screened for thiamine, riboflavin and niacin production. Thiamine, riboflavin and niacin produced were quantified. The five lactic acid bacteria isolated were Lactobacillus plantarum,Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus casei and Lactococcuslactis. The most frequent isolate was Lactobacillus plantarum (100%) followed by Lactobacillus caesi (75%). Lactobacillus brevis, Lactobacillus fermentum and Lactobacillus lactis were the least isolates having (50%) occurrence each. Lactobacillus plantarum produced the highest amount of thiamine (5.8833µg/100ml) and riboflavin (5.0400µg/100ml) while Lactobacillus lactis had the least thiamine (5.2267µg/100ml) and Lactobacillus caesi had the least riboflavin (4.8300µg/100ml). Lactobacillus casei produced the highest niacin (1.6433µg/100ml) while Lactobacillus fermentum had the least (1.2900µg/100ml). This study revelsLactobacillus plantarum as the most efficient thiamine and riboflavin producer. Lactobacillus caseiproduced the most niacin. 

TABLE OF CONTENTS

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Tables of contents v

List of tables vi

Abstract vii

Chapter One

1.0 Introduction 1

1.1 Aim 2

1.2 Objectives 2

Chapter Two

2.1 Lactic Acid Bacteria (LAB) 3

2.2 What are Lactic Acid Bacteria? 3

2.3. Physiology and Morphology 5

2.4  General Description 7

2.5  Genetics 9

2.6. Application of Lactic Acid Bacteria 10

2.7.  Lactic Acid Bacteria as Source of Probiotics 11

2.7.1 Probiotics and Health 13

2.8 Lactic Acid Bacteria as Source of Starter Cultures 14

2.8.1 Starter Culture and Functional Starter Cultures in Fermentation of Foods 14

2.8.2 Probiotics as Functional Starter Culture 14

2.8.3 Functional Starter Cultures in Fermented Dairy Products 17

2.8.4 Functional Starter Cultures in Fermented Non Dairy Products. 17

2.8.4.1. Fermented Meat and Meat Products 17

2.8.4.3. Starter Culture in Silage 17

2.9 Lactic Acid Bacteria as Source of Antimicrobial Agents. 18

2.9.1 Bacteriocins 19

2.10. Lactic Acid Bacteria as a Source of Vitamins 19

2.10.1 Folate 20

2.10.2. Vitamin B12 21

2.10.3 Vitamin K 21

2.10.4 Riboflavin 22

2.11. Lactic Acid Bacteria as Source of Enzymes 22

2.12. Lactic Acid Bacteria as Source of Exopolysaccharides 23

2.13. Lactic Acid Bacteria as Source of Low-Calories Sweeteners. 24

Chapter Three

3.0 Materials and Method 25

3.1 Source of Materials 25

3.2 Sample Preparation 25

3.3 Media Preparation 25

3.4 Isolation of Lactic Acid Bacteria 26

3.5. Morphological Identification of Bacterial Isolates. 26

3.5.1 Gram Staining 26

3.5.2 Biochemical Parameters. 27

3.6.1. Determination of Thiamine (Vitamin B1) 29

3.6.2 Determination of Riboflavin (Vitamin B2¬) 31

3.6.3. Determination of Niacin (Vitamin B3) 31

3.7 Statistical Analysis 32

Chapter Four

Results 33

Chapter Five

5.1 Discussion 38

5.2 Conclusion 40

References

Appendix