Characterization And Identification Of Microorganisms Involved In Wood Deterioration

ABSTRACT

The study evaluated the isolation and characterization of microorganisms involved in wood degradation. A total of six bacterial and four fungal isolates were found to be responsible for the deterioration of used and unused wood samples. These microorganisms were isolated using the streak plate technique. The bacteria species isolated and identified using morphological and biochemical characterization included; Escherichia coli, Staphylococcus aurues, Klebsiella species, Serratia species, Citrobacter species, and Bacillus species, while the fungi species are Aspergillus niger, Aspergillus fumugatus, Mucor alternaria and Rhodotorula spp. Amongst the five (5) used wood samples, Ash wood (used) had the highest bacteria count at 7.6x1011while among the unused wood samples Beach wood (unused) was recorded to have the highest bacteria count at 7.3x1011 and Fibreboard (unused) having the least fungi count at 3.5 x1011. It was also observed that Escherichia coli is the most frequently occurring isolates with a high percentage occurrence of (20.0%) and (22.2%) respectively, followed by Staphylococcus aureus (16.0%) and (16.6%). The occurrence of Escherichia coli is usually associated with faecal matter and also affirmed poor hygiene in the area. Among the fungal isolates, Aspergillus niger (8.3 %), (16.6%) was the most predominant and frequently occurring isolates on both wood types. The extracellular enzymes activities for isolate revealed that Staphylococcus aureus, Bacillus spp and Citrobacter species were found to exhibit the highest enzymes production. Statistical analysis showed that there were significant differences in the bacterial mean count of the wood samples at P< 0.05, while no significant was recorded on fungal meant count of the wood samples.

TABLE OF CONTENTS

Title Page ﾿   ﾿ i

Certification ﾿ iii

Dedication ﾿ iv

Acknowledgement ﾿ v

Table of Contents ﾿ vi

List of Tables ﾿ ix

Abstract ﾿ x

CHAPTER ONE

1.1 ﾿ INTRODUCTION ﾿ 1

1.2 ﾿ Aim and Objectives ﾿ 1

CHAPTER TWO

2.0 ﾿ LITERATURE REVIEW ﾿ 2

2.1 ﾿ Wood and its Component ﾿ 2

2.1.1 ﾿ Cellulose ﾿ 2

2.1.2 ﾿ Hemicellulose ﾿ 3

2.1.3 Lignin ﾿ 3

2.2 ﾿ TYPES OF WOOD ﾿ 4

2.2.1 ﾿ Beech Wood ﾿ 4

2.2.2 ﾿ Ash Wood ﾿ 5

2.2.3 ﾿ Fibreboard ﾿ 5

2.2.4 ﾿ Plywood ﾿ 5

2.2.3 ﾿ Veneer ﾿ 5

2.3 ﾿ CLASSIFICATION OF WOOD ﾿ 6

2.3.1 ﾿ Hardwoods ﾿ 6

2.3.1.1 ﾿ Maple ﾿ 6

2.3.1.2 ﾿ Mahogany ﾿ 7

2.3.1.3 ﾿ Cherry ﾿ 7

2.3.1.4 ﾿ Walnut ﾿ 8

2.3.2 ﾿ Softwoods ﾿ 8

2.3.2.1 ﾿ Pine ﾿ 8

2.3.2.2 ﾿ Ash ﾿ 8

2.3.2.3 ﾿ Birch ﾿ 9

2.3.2.3 ﾿ Cedar ﾿ 9

2.3.2.4 ﾿ Redwood ﾿ 9

2.3.2.4 ﾿ Hemlock ﾿ 10

2.4 ﾿ WHERE WOODS CAN BE FOUND IN NIGERIA ﾿ 10

2.4.1 ﾿ The Makoko-Oko Baba Wood Market ﾿ 10

2.4.2       The Umuahia Modern Timber Market ﾿ 11

2.5 ﾿ Degradation of Wood by Fungi ﾿ 11

2.5.1 ﾿ White-rot Fungi ﾿ 12

2.5.2 ﾿ Brown-Rot Fungi ﾿ 12

2.6 ﾿ Microbial Colonization of Wood ﾿ 13

2.7 ﾿ Diversity of Bacterial Communities in Wood ﾿ 14

2.7.1 ﾿ Edaphic and Atmospheric Sources of Bacteria ﾿ 15

2.7.2 ﾿ Bacterial Endophytes ﾿ 16

2.8 ﾿ Bacterial Nitrogen Fixation in Wood ﾿ 16

2.9 ﾿ Bacterial Wood Decomposition ﾿ 18

2.10 ﾿ Isolation and Characterization of Microorganisms Involved in 

﾿ Degradation of Wood Waste ﾿ 18

CHAPTER THREE

3.0 ﾿ MATERIALS AND METHOD ﾿ 21

3.1 ﾿ Study Area ﾿ 21

3.2 ﾿ Collection of Samples ﾿ 21

3.3 ﾿ Sterilization of Materials ﾿ 21

3.4 ﾿ Preparation of Culture Media ﾿ 22

3.5 ﾿ Isolation of Hydrolytic Microorganisms from Wood Chips ﾿ 22

3.6 ﾿ Screening of Hydrolytic Enzyme-Producing Microorganisms from Wood Chips ﾿ 22

3.7 ﾿ Identification of the Isolates ﾿ 23

3.8 ﾿ Gram Staining ﾿ 23

3.9 ﾿ Biochemical Test ﾿ 24

3.9.1 ﾿ Catalase Test ﾿ 24

3.9.2 ﾿ Indole Test ﾿ 24

3.9.3 ﾿ Citrate Utilization Test ﾿ 24

3.9.4 ﾿ Hydrogen Sulphide (H2S) Production Test ﾿ 24

3.9.5 ﾿ Starch Hydrolysis ﾿ 25

3.9.6 ﾿ Motility, Indole, Urease (MIU) ﾿ 25

3.9.7 ﾿ Coagulase Test ﾿ 26

3.9.8 ﾿ Oxidase Test ﾿ 26

3.10 ﾿ Identification of Fungal Isolates ﾿ 26

3.10.1 ﾿ Wet Preparation ﾿ 26

3.10.2 ﾿ Colonial Morphology ﾿ 26

3.11 ﾿ Qualitative Screening for Extracellular Enzyme Producing Isolate by Plate Assay ﾿ 26

3.11.1 ﾿ Purification of Isolate ﾿ 26

 3.11.2 ﾿ Production of Xylanase Enzyme ﾿ 28

3.11.3 ﾿ Production of Amylases Enzyme ﾿ 28

3.11.4 ﾿ Production of Cellulases Enzyme ﾿ 28

3.12 ﾿ Statistical Analysis ﾿ 28

CHAPTER FOUR

4.0 ﾿ RESULTS ﾿ 29

CHAPTER FIVE

5.0 ﾿ DISCUSSION, CONCLUSION AND RECOMMENDATION ﾿ 42

5.1 ﾿ Discussion ﾿ 42

5.2 ﾿ Conclusion ﾿ 44

5.3 ﾿ Recommendation ﾿ 45

﾿ References 

﾿ Appendix I

﾿ Appendix II