ABSTRACT
The
industrial importance of gelatinase cannot be overemphasized as more jaw
dropping discoveries have uncovered the various undisputable applications of
the enzyme in several aspects of science. In this study, gelatinase producing
bacteria were probed from sediment samples of Kwa River and Atimbo River, Cross
River State. Primary screening uncovered 3 isolates (B5, A7 and B6) that could
elaborate gelatinase activity. This exposed the quantity of gelatinolytic
bacteria to be 5.4% of the entire sediment sample population. The isolates that
showed positive gelatinolytic activity were then quantitatively screened using
the Bradford method which displayed high production in 2 isolates (B6 and
B5). The isolate that showed maximum
gelatinolytic activity was then centrifuged and evaluated to determine the
extracellular production of the enzyme using cell free supernatants. The cell
free supernatants of positive isolates were used as crude gelatinase.
Determination of carbon source required by the bacteria for optimal production
of the gelatinase showed high rates of enzyme activity in sucrose which was
selected. The successful organism was identified to be of Bacillus species
using identification tests.
TABLE OF CONTENTS
Title page i
Certification
ii
Dedication iii
Acknowledgements
iv
Abstract
v
Table of Contents
vi
List of Figures
vii
List of Plates
viii
List of Tables
ix
CHAPTER ONE: INTRODUCTION
1
Aim and objectives of study
3
Justification of study
3
CHAPTER TWO: LITERATURE REVIEW 4
Gelatins
4
Sources of gelatin
7
Production of gelatin
9
Gelatin structure
12
Mechanism of gelatin gelation 14
Properties of gelatin
15
Industrial applications of gelatin
17
Proteases
21
Microbial proteases
22
Applications of microbial proteases 24
Matrix Metalloproteases (MMPs)
27
Gelatinase
29
Types of gelatinases 30
Structure of gelatinases
31
Activation of gelatinases
32
Initiation of gelatinases
33
CHAPTER THREE: MATERIALS AND METHODS 34
Materials
34
Methods
34
Sampling
34
Sample collection
34
Sample preparation
35
Microbial analysis
35
Enumeration
36
Isolation
36
Primary screening for gelatinase-liquefying bacteria 36
Secondary screening for gelatinase production in submerged
culture 37
Evaluation of carbon sources for optimal gelatinase
production 39
Characterization and identification of selected
gelatinase-producing bacterium
41
CHAPTER FOUR: RESULTS
42
Microbial analysis 42
Primary screening for gelatinase-liquefying bacteria 42
Secondary screening for gelatinase production in submerged
culture 43
Evaluation of carbon sources for optimal gelatinase production 43
Characterization and identification of selected
gelatinase-producing bacterium
44
CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATION 49
Discussion
49
Conclusion
50
Recommendation
51
References