biodiversity and antibiotic activity of actinomycetes isolated from cat ba island, vietnam = đa dạng sinh học và hoạt tính kháng sinh của các chủng xạ khuẩn phân lập ở đảo cát bà, việt nam tt

Le Phuong Chung BIODIVERSITY AND ANTIBIOTIC ACTIVITY OF ACTINOMYCETES ISOLATED FROM CATBA ISLAND, VIETNAM MASTER THESIS MAJOR BIOTECHNOLOGY HANOI – 2011 UNIVERSITY OF LIEGE *** VIET

Le Phuong Chung

BIODIVERSITY AND ANTIBIOTIC ACTIVITY OF ACTINOMYCETES ISOLATED FROM CATBA

ISLAND, VIETNAM

MASTER THESIS MAJOR BIOTECHNOLOGY

HANOI – 2011

UNIVERSITY OF LIEGE

***

VIETNAM NATIONAL UNIVERSITY, HANOI

INSTITUTE OF MICROBIOLOGY AND BIOTECHNOLOGY

***

Le Phuong Chung

BIODIVERSITY AND ANTIBIOTIC ACTIVITY OF ACTINOMYCETES ISOLATED FROM CATBA

ISLAND, VIETNAM

Speciality: Biotechnology Code: 60 42 80

MASTER THESIS MAJOR BIOTECHNOLOGY

SUPERVISORS: Dr NGUYEN HUYNH MINH QUYEN

Dr NGUYEN QUYNH UYEN

HANOI – 2011

LIEGE UNIVERSITY

***

VIETNAM NATIONAL UNIVERSITY, HANOI

INSTITUTE OF MICROBIOLOGY AND BIOTECHNOLOGY

***

CONTENTS

Acknowledgements i

Abbreviations ii

List of figures iii

List of tables iv

Abstract .1

Tóm tắt 3

Foreword 5

Chapter 1 Introduction 6

1.1 Antibiotic 6

1.1.1 General introduction 6

1.1.2 History of the development of antibiotics 7

1.1.3 Classification of antibiotics 9

1.1.4 Anti-tumor antibiotics 13

1.1.5 The need of developing new antibiotics 14

1.2 Actinomycetes 14

1.2.1 General characteristics 14

1.2.2 Actinomycetes and secondary metabolites 16

1.3 Objectives of the study 16

Chapter 2 Materials and methods 18

2.1 Work flow 18

2.2 Methods 19

2.2.1 Isolation of actinomycetes 19

2.2.2 Targeted microorganisms 21

2.2.3 Screening antibiotic producing actinomycetes 21

2.2.4 Ethyl-acetate extraction 22

2.2.5 Chromatography analyses of antibiotics 22

2.2.6 Screening for cytotoxicity 24

2.2.7 Taxonomical identification of actinomycete isolates 25

Chapter 3 Results and discussion 28

3.1 Biodiversity of the actinomycete isolated from Catba island 28

3.2 Screening for antibiotic producing actinomycetes 29

3.3 Chromatography analyses of crude extracts of the selected strains 31

3.3.1 Thin Layer Chromatography (TLC) 31

3.3.2 High – Performance Liquid Chromatography (HPLC) 32

3.4 Primary study on cytotoxicity activity 33

3.4.1 pH-dependent color change by the selected strains 33

3.4.2 Cytotoxicity assay against human cell lines 33

3.5 Identification of the actinomycete isolates 34

3.5.1 Morphology-based identification for the Streptomyces isolates 35

3.5.2 16S rDNA sequence-based identification for the non-Streptomyces isolates 37

Conclusion and Suggestion 38

Bibliography 40

Appendix 1 Culture media 46

Appendix 2 The 16S rDNA sequence……… …….46