Nan Xiang
Report of GLOMAR PhD student Nan Xiang about her research placement in Konstanz, Germany, at the University of Konstanz from October to December 2021.
I started my PhD in November 2018, and my project aims to understand how microbes drive nutrient cycling in coral symbiosis, with main focus on exploring which prokaryotes are involved and what are (a)biotic drivers for them. Our recent study suggested that a majority of putative denitrifying bacteria in the coral holobiont were core microbiome of algal symbionts. Still limited, our finding is based on the functional attribution of 16S rRNA sequencing data. It would be a major advance if we could distinguish the respective (in)direct contribution of coral host and algal symbionts to the structuring of denitrifying bacterial community using nitrite reductase nirS gene sequencing.
In this light, I conducted my research stay in the group of Prof. Dr. Christian Voolstra at the University of Konstanz from October to December 2021. Here, we take the unique advantage of the coral model sea anemone (‘Aiptasia’), and use nirS metabarcoding sequencing to characterize the denitrifying bacterial community in six host-algal combinations of Aiptasia. This is a project with both opportunities and challenges; I really appreciated that three of my thesis committee members (Prof. Dr. Astrid Gärdes, Prof. Dr. Christian Wild, and Prof. Dr. Christian Voolstra) agreed and supported my research stay. To catch up the schedule, my lovely advisors, Dr. Claudia Pogoreutz and Dr. Nils Rädecker had started the algal depletion and inoculations in Aiptasia animals six months before my arrival. We three worked together to collect samples, measure physiological parameters, and prepare the library for nirS sequencing. Thanks to their generous knowledge sharing and patient guidance, it was such a productive and fun time. When nirS sequencing data arrived in November 2021, I got the support from Dr. Anny Cárdenas in guiding me analyze and visualize the data. Her wise and kind guidance makes me feel that running code is not a stressful thing anymore but is an interesting thing that makes my work more logistic and efficient.
I also enjoyed my time exploring nature in southern Germany. The landscape is perfect for cycling and hiking, and I marveled at the breathtaking mountains and lakes. Taken together, my research stay in Konstanz is definitely one of the most precious memories of my PhD life. More lovely colleagues and friends to thank: Alyssa, Gabi, Rach, Ben, Kris, Petra, Melanie, Valent, Guanwen, … Finally, I am deeply grateful to the GLOMAR for the generous financial support for my research stay.
