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