Lactic Acid Bacterial Species Associated With Locally Fermented Maize

ABSTRACT

Lactic Acid Bacteria play key roles in the fermentation of maize to akamu. The lactic acid bacterial species associated with the local fermentation of maize were isolated, characterized and identified. The isolation of the lactic acid bacteria was done by culturing of the sample after serial dilution on MRS agar for 24hrs at 37oC. The isolates obtained were subcultured on a nutrient agar to obtain a pure culture of the lactic acid bacteria. The occurrences of the lactic acid bacteria were determined. The characterization and identification of the lactic acid bacteria was achieved by the different biochemical tests that were carried out such as the, sugar fermentation, catalase. The morphology, gram reaction and colony features were also investigated. The 12 samples showed high microbial load which ranged from 1.8×106cfu/ml to 2.8×106cfu/ml. A total of 43 lactic acid bacteria were isolated which comprised of Lactobacillus spp (12), Streptococcus spp (9), Lactococcus spp (7), Pediococcus spp (8) and Leuconostoc spp (7). Lactobacillus spp had 100% occurrence in the 12 samples. Lactic acid bacteria are essential bacteria responsible for the fermentation of maize to akamu.

TABLE OF CONTENTS

Title page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgements ﾿ iv

Table of contents ﾿ vi

List of tables ﾿ vii

Abstract ﾿ viii

CHAPTER ONE

1.0 ﾿ ﾿ Introduction ﾿ 1

1.1 ﾿ Food fermentation ﾿ 1

1.2 ﾿ Akamu ﾿ 2

1.3 ﾿ Aim ﾿ 3

1.4 ﾿ Objectives ﾿ 3

CHAPTER TWO

2.0 ﾿ Literature review ﾿ 4

2.1 ﾿ Lactic acid bacteria ﾿ 4

2.2 ﾿ Physiology and morphology ﾿ 6

2.3 ﾿ General description of lactic acid bacteria ﾿ 8

2.4 ﾿ Applications of lactic acid bacteria ﾿ 9

2.5 ﾿ Cereal ﾿ 12

2.6 ﾿ Maize ﾿ 13

2.6.1 ﾿ Distribution ﾿ 14

2.6.2 ﾿ Nutritional Value and Health Benefits ﾿ 14

2.6.3 ﾿ Medicinal Value ﾿ 15

2.6.4 ﾿ Economic Importance ﾿ 15

CHAPTER THREE

3.0 ﾿ Materials and methods ﾿ 16

3.1 ﾿ Sources of material ﾿ 16

3.2 ﾿ Sample preparation ﾿ 16

3.3 ﾿ Preparation of media for bacteria isolation ﾿ 16

3.4 ﾿ Enumeration of bacteria from locally fermented maize  ﾿ 16

3.5 ﾿ Isolation of microorganism ﾿ 17

3.6 ﾿ Characterization of bacteria isolates ﾿ 17

3.6.1 ﾿ Colony features of bacteria isolates ﾿ 17

3.6.2 ﾿ Microscopic Feature ﾿ 17

3.6.3    Biochemical Tests for Identification of Bacteria ﾿ 18

3.7      ﾿ Identification of isolates ﾿ 19

CHAPTER FOUR

4.0 ﾿ Results ﾿ 20

CHAPTER FIVE

5.0 ﾿ Discussion ﾿ 25

5.1 ﾿ Conclusion ﾿ 25

REFERENCES ﾿