I would like to express my heartfelt gratitude to my supervisor, Prof Ng Wun Jern, for the invaluable encouragement, careful technical guidance, and extraordinary patience throughout my candidature period. Without his support and supervision, this work would not have been possible. I am indebted forever for the kindness and care he had for me when I was going through my hardships.I would like to thank my co-supervisor, Prof William Chen, and my mentor, Prof Liu Yu, for their valuable suggestions and continuously improving my thesis. I would like to thank Dr. Babu Narayanaswamy for being more than a mentor, especially during the final year of my candidature. I would also extend my thanks for trusting my abilities and allowing me to finish my Graduate Assistantship Program duty under his supervision. I would like to thank Prof Lisak Grzegorz for allowing me to work on his project to clock my Research assistantship duty. I learned a lot during my time as an RA. Special thanks to Dr. Harish Venkata Krishnan, who taught me microbiological techniques during my first year. Special thanks to Dr. Dave Poh and Dr. Pan Chaozhi for helping me clarify my technical doubts in my research work and providing invaluable feedback on my data and manuscripts. I would like to express my thanks to all the lab technicians, staff, colleagues, and friends at AEBC, NEWRI. I would like to acknowledge Interdisciplinary Graduate School, Nanyang Technological University (NTU) and NEWRI Singapore, for the financial support throughout this project and the opportunity to conduct this research. I would like to especially thank Ms. Elvy Riani Wanjaya, Dr. Lv Yunbo, Dr. Han Yuan for training me on various high-end analytical instruments that are key for this study. Thanks to Ms. Hera for always being kind and helpful from day one and making my life as easy and smooth as possible at AEBC, NEWRI, SG.