ABSTRACT

This study was conducted to isolate sulphur oxidising bacteria from Oguta lake of Oguta local government area, Imo state and  their sulphur oxidation ability was evaluated. Results showed that in total five sulphuroxidising bacteria were isolated from four different points of the lake. From the qualitative screening it was found that out of the Nine bacterial isolates, five isolates could efficiently reduce the pH of the medium upto 3.8 from the initial pH 8.1. Their sulphate ion production abilities were in the range of 1.67 mg/ml-2.58 mg/ml. From morphological and biochemical characterisation, most of the isolates were identified as Micrococcus sp., Bacillus sp., Pseudomonas sp., Klebsiella sp. and xanthobacter sp.

TABLE OF CONTENT

Cover Page i

Title Page ii

Certification iii

Dedication iv

Acknowledgement v

Table of content vi

List of Tables vii

Abstract viii

Chapter One

1.1 Introduction      1                                                                                1.2 Statement of Problem 3

1.3 Aim and Objective 3

1.3.1 Specific Objective 3

Chapter Two

Literature Review 4

2.1 Sulphur Oxidizing Microorganisms 4

2.2 The Sulphur-Oxidizing Bacteria 5

2.3 Other Sulphur Bacteria 6

2.4 Isolation,Characterization And Identification Of Sulphur Oxidizing Bacteria 6

2.4.1 Isolation 6

2.4.2 Characterization and Identification 7

2.5 Review of Sulphur Oxidizing Bacteria 9

2.5.1 Isolation of Sulphur-Oxidizing Bacteria At 37°C & 50°C 10

2.5.2 Moderately ThermophilicSulphur-Oxidizing Bacteria 11

2.6 Forms of Sulphur Oxidizing Bacteria 11

2.6.1 Green Sulfur Bacteria 11

2.6.2 Purple Sulfur Bacteria 12

2.6.3 Thiobacillus 12

2.6.4 Thermococcus 13

2.7 Effect of Sulfur Bacteria or Hydrogen Sulfide 13

2.7.1 Problems Associated With Sulfur Bacteria Or Hydrogen Sulfide 14

2.8 Sulfates and Hydrogen Sulfide 14

2.8.1 Sulfate\ 15

2.8.2 Hydrogen Sulfide 15

2.9 Health Issues Associated With Sulfate 16

2.10 Testing Options for Sulphur 17

2.11 Drinking Water Standards 17

2.12 Oxidation 22

2.12.1 Photoautotrophic Oxidation of Sulphide 23

2.12.2 ChemolithothrophicSulphide Oxidation 24

2.13 Enzyme Responsible For Sulphur Oxidation 26

2.14 Sox Gene InSulphurOxidising Bacteria 27

2.15 Some Important Biological Application OfSulphur Oxidizing        Bacteria 28

2.15.1 Bioleaching 28

2.15.2 Biofertiliser 28

2.15.3 Plant Growth Promotion 29

2.15.4 Biocontroling Agent 29

2.15.5  Deodorization 30

2.15.6 Rubber Recycling 30

Chapter Three: Materials and Methods 32

3.1 Source of Materials 32

3.2 Sampling and Sample Preparation 32

3.2.2 Preparation Of Medium For Qualitative Sulphur Oxidizing Test

(Thiosulphate Agar Broth). 32

3.3      Preparation of Media For Bacteria Isolate. 33

3.4. Isolation of Bacteria 33

3.5. Qualitative Screening for Sulphur Oxidizing Bacteria Isolates 34

3.6. Determination of Sulphur Production Activity Of Sob Isolates 34

3.7.   Identification of Sulphur Oxidizing Isolates 35

3.7.1   Morphological Characterisitcs 35

3.7.2  Gram Staining 36

3.7.2. Biochemical Characteristics 36

3.7.4. Identification 37

Chapter Four: Result 38

Chapter Five    Discussion and Conclusions 

5.1    Discussion 44

5.2    Conclusion 45

        References

       Appendix