DETERMINATION OF PROBIOTIC POTENTIALS OF LACTIC ACID BACTERIA ISOLATED FROM TRADITIONAL FERMENTED FOODS.

ABSTRACT

This study investigated the determination of probiotic potential of Lactic Acid Bacteria from traditional fermented foods. A total of 34 Lactic Acid Bacteria were identified, characterized and isolated. The study found out that LAB count were 9 Lactobacillus plantarum and Streptococcus species, having the highest and the lowest counts respectively. Most isolates (5) were present in Ogi, tomatoes and Ugba and Lactococcus lactis was the most tolerant to the heat treatment at 10, 30 and 60 minutes respectively while Streptococcus species have the lowest bile salt tolerance after exposure for 3 and 4 hours respectively. These results proved that lactobacillus which can be isolated from fermented foods are good sources of probiotics and thus recommend the uses of probiotic LAB and their application because probiotics can be of many health benefits to humans.

TABLE OF CONTENTS

Title                                                                                                                                           Page

Title Page                                                                                                                                        ii

Certification                                                                                                                                  iii

Dedication                                                                                                                                      iv

Acknowledgements                                                                                                                        v

Table of Contents                                                                                                                           vi

List of Figures                                                                                                                                 ix

List of Tables                                                                                                                                  x

Abstract                                                                                                                                          xi

CHAPTER ONE: INTRODUCTION                                                                                                      1

1.1. The History of Probiotics                                                                                                           2

1.2. Aims and Objectives                                                                                                                 3

CHAPTER 2: LITERATURE REVIEW                                                                                     5

2.1.    Raw Material Development                                                                                                   5

2.2.   Development OF Fermentation Processes                                                                               6

2.3     Purpose and Benefits Of Food Fermentation                                                                         8

2.3.1   Health Benefits Of Fermented Foods                                                                                    8

2.4     Food and Beverage Fermentation by LAB                                                                          10

2.5     Role and Importance of LAB in Traditional Fermented Foods                                            12

2.6     LAB as Probiotics                                                                                                                12

2.6.1  The Role Of LAB in Immune System Modulation And Mental Health                     13

2.7       LAB as a Source of Antimicrobial Agents                                                                         14

2.7.1    Antifungal Agents and Other Antimicrobial Agents from LAB                                             14

2.7.2    Antimicrobial Activity and Safety                                                                                     14

2.7.3.   Other Selection Criteria for Probiotic LAB                                                                       15

CHAPTER 3. MATERIALS AND METHODS

3.1.    Sample Collection                                                                                                                16

3.2.    Sterilization of Materials                                                                                                      16

3.3.    Media Preparation for Isolation of Lactic Acid Bacteria                                                     16

3.4.   Microbiological Analysis                                                                                                      17

3.5.   Identification of Isolates                                                                                                        17

3.6.   Gram Staining                                                                                                                      17

3.7.   Motility Test (Hanging Drop Method)                                                                                  18

3.8.   Biochemical Tests                                                                                                                 18

3.8.1.  Catalase Test                                                                                                                        18

3.8.2.   Coagulase Test (Slide Test)                                                                                               18

3.8.3.   Oxidase Test                                                                                                                       19

3.8.4   Citrate Utilization Test                                                                                                        19

3.8.5.  Indole Test                                                                                                                          20

3.8.6.  Voges-Proskauer Test                                                                                                          20

3.8.7.  Methyl Red Test                                                                                                                  20

3.8.8.  Sugar Utilization Test                                                                                                          21

3.9     Food Pathogen Indicator Bacteria                                                                                        21

3.10.   Determination Of Probiotic Characteristics Of The Lactic Acid Bacteria Isolates                 21

3.10.1.  Production Of Crude Bacteriocin                                                                                      21

3.10.2.   Antibacterial Activity of Lactic Acid Bacteria                                                                22

3.10.3.  Acid Tolerance                                                                                                                  22

3.10.4. Tolerance to Bile Salts                                                                                                       23

3.10.5.  Thermo Tolerance                                                                                                             23

3.10.6.   Antibiotic Activities of the LAB Isolates                                                                         24

CHAPTER 4: RESULT

 Result                                                                                                                                             25

CHAPTER  5:  DISCUSSION, CONCLUSION AND RECOMMENDATION

Discussion                                                                                                                                       44

Conclusion                                                                                                                                      49

Recommendation                                                                                                                           49

References                                                                                                                                      50

LIST OF FIGURES

Figure1. Flow Chart of Cassava Processing                                                                                     6

Figure 2  Packaging Of Iru By Traditional And Modern Industrial Methods                                8

LIST OF TABLES

Table 4.1: Average Total Lactic Acid Bacteria (LAB) Count From Fermented Food Sample    30

Table 4.2: Identification And Characterization Of Lactic Acid Bacteria (LAB) Isolates             33

Table 4.3: Distribution of Lactic Acid Bacteria (LAB) Isolates from Traditional

     Fermented Food                                                                                                            34

Table 4.4: Percentage Occurrence of Lactic Acid Bacteria (LAB) Isolates From Traditional

     Fermented Food                                                                                                            35

Table 4.5: Antibacterial Activity of the Lactic Acid Bacteria (LAB) Isolates                               36

Table 4.6: Activities of Acid Tolerance of the Lactic Acid Bacteria (LAB) Isolates                   37

Table 4.7: Activities of Bile Salt Tolerance of the Lactic Acid Bacteria (LAB) Isolates             38

Table 4.8a: Activities of Thermo Tolerance of the Lactic Acid Bacteria (LAB) Isolates at 10

      minutes                                                                                                                        39

Table 4.8b: Activities of Thermo Tolerance of the Lactic Acid Bacteria (LAB) Isolates at 30

       minutes                                                                                                                       40

Table 4.8c: Activities of Thermo Tolerance of the Lactic Acid Bacteria (LAB) Isolates at 60

        minutes                                                                                                                      41

Table 4.9a: Antibiotic Susceptibility Patterns of the Lactic Acid Bacteria (LAB) Isolates from

      Fermented Food                                                                                                          42

Table 4.9b: Antibiotic Susceptibility Patterns Of The Lactic Acid Bacteria (LAB) Isolates From  

      Fermented Food                                                                                                           43

CHAPTER ONE

1.0       Introduction

Probiotic bacteria may produce various compounds, which are inhibitory to the pathogen’s growth, which include organic acids (lactic and Acid acids), bacteriocins, and reuterin. The organic acids not only lower the pH, thereby affecting the growth of the pathogen, but they can also be toxic to the microbes (Tambekar and Bhutada, 2010). There is increasing evidence that probiotics are beneficial in gastrointestinal disturbances, such as diarrhoea, dysentery, typhoid etc (Tambekar and Bhutada, 2010). It is important to underline when considering the effectiveness and biological activity of probiotics, prebiotics or their combination (synbiotics) that they are food products and not drugs.

Furthermore, in many cases, their effects are mainly prophylactic in nature, rather than therapeutic, i.e. preventive rather than curative (Suskovic et al., 2001). Lactic acid bacteria were referred to as probiotics in scientific literature by Lilley and Stillwell. Lactic acid bacteria (LAB) are a group of Gram positive, non-spore forming, cocci or rods which produce lactic acid as major end product from fermentation of carbohydrates. Majority of microorganisms used as probiotics are the Lactic acid bacteria and bifidobacteria. Within the group of LAB, Lactobacillus species are most commonly utilized group of microorganisms for their potential beneficiary properties as probiotics. The antagonistic activity of such bacteria is known to inhibit a large number of enteric and urinary pathogenic bacteria (Hutt et al., 2006). Lactic acid bacteria including Lactobacillus, leuconostoc, Lactococcus, pediococcus and Bifidobacterium are found throughout the gastrointestinal tract. Lactobacillus and Bifidobacterium spp. are prominent members of the intestinal flora and are the commonly studied probiotics bacteria. They cause reduced lactose intolerance alleviation of some diarrhoeas, lowered blood cholesterol, increased immune response and prevention of cancer.

The selection criteria for probiotic LAB include: safety, viability/activity in delivery vehicles, resistance to acid and bile, adherence to gut epithelial tissue ability to colonise the gastro intestinal tract, production of antimicrobial substances, ability to stimulate a host immune response and the ability to influence metabolic activities such as vitamin production, cholesterol assimilation and lactose activity (Savodago et al., 2006).

1.1       THEHISTORYOFPROBIOTICS

The word ‘probiotic’ comes from Greek language ‘pro bios’ which means ‘for life’ opposed to ‘antibiotics’ which means ‘against life’. The history of probiotics began with the history of man by consuming fermented foods that is well known Greek and Romans consume very much (Guarneret al., 2005).

In 1908 a Russian researcher Ellie Metchnikoff, who has a nobel prize, firstly proposed the beneficial effects of probiotic microorganisms on human health. Metchnikoff hypothesized that Bulgarians are healthy and long lived people because of the consumption of fermented milk products which consists of rod shaped bacteria (Lactobacillus spp.). Therefore, these bacteria affect the gut microflora positively and decrease the microbial toxic activity (Chuayana et al., 2003).

The term ‘probiotic’ firstly used in 1965 by Lilly and Stillwell to describe substances which stimulate the growth of other microorganisms. After this year the word ‘probiotic’ was used in different meaning according to its mechanism and the effects on human health. The meaning was improved to the closest one we use today by Parker in 1974. Parker defined ‘probiotic’ as ‘substances and organisms which contribute to intestinal microbial balance’. In 1989, the meaning use today was improved by Fuller. Thus, probiotic is a live microbial supplement which affects host’s health positively by improving its intestinal microbial balance (Sanders 2003).

 In the following years lots of researchers studied on probiotics and made so much definition.

Ø  ‘Living microorganisms, which upon ingestion in certain numbers, exert health benefits beyond inherent basic nutrition(Shaafasma, 1996).

Ø  ‘A microbial dietary adjuvant that beneficially affects the host physiology by modulating mucosal and systemic immunity, as well as improving nutritional and microbial balance in the intestinal tract(Naidu et al., 1999).

Ø  ‘A live microbial food ingredient that is beneficial to health’ (Salminen et al., 1998).

Ø  ‘A preparation of or a product containing viable, defined microorganisms in sufficient numbers, which alter the microflora (by implantation or colonization) in a compartment of the host and by that exert beneficial health effects in this host’ (Schrezenmeir and de Vrese, 2001).

Ø  ‘Live microorganisms which when administered in adequate amounts confer a health benefit on the host’ is accepted by FAO/WHO (Guarner, et al., 2005).

1.2       AIMS AND OBJECTIVES

1.2.1   Aim

The aim of this project is to determine the probiotic potential of lactic acid bacteria isolated from traditional fermented foods.

1.2.2   Objectives

The specific objectives are,

      i.         To determine Lactic Acid Bacteria (LAB) count from the fermented food sample

     ii.         To identify and characterize Lactic Acid Bacteria isolates from the fermented foods

   iii.         To determine the survival rates of the Lactic Acid Bacteria from the fermented foods

   iv.         The antibiotics susceptibility pattern of the Lactic Acid Bacteria from the fermented foods.

Buyers has the right to create dispute within seven (7) days of purchase for 100% refund request when you experience issue with the file received. 

Dispute can only be created when you receive a corrupt file, a wrong file or irregularities in the table of contents and content of the file you received. 

ProjectShelve.com shall either provide the appropriate file within 48hrs or send refund excluding your bank transaction charges. Term and Conditions are applied.

Buyers are expected to confirm that the material you are paying for is available on our website ProjectShelve.com and you have selected the right material, you have also gone through the preliminary pages and it interests you before payment. DO NOT MAKE BANK PAYMENT IF YOUR TOPIC IS NOT ON THE WEBSITE.

In case of payment for a material not available on ProjectShelve.com, the management of ProjectShelve.com has the right to keep your money until you send a topic that is available on our website within 48 hours.

You cannot change topic after receiving material of the topic you ordered and paid for.