SZU-HKUST Joint PhD Dayu Zou published a paper titled “Genomic adaptation to eutrophication of ammonia-oxidizing Archaea in the Pearl River estuary” in Environmental Microbiology. (Impact Factor 5.434). Dr. Dayu Wei is the first author of the paper, and Prof. Meng Li from IAS and Prof. Hongbin Liu from HKUST are as the corresponding authors.
Ammonia-oxidizing archaea (AOA) are ubiquitous in natural ecosystems, and they are responsible for a significant fraction of ammonia oxidation globally. Since the first AOA isolate was established a decade ago, molecular surveys of their environmental distribution (based primarily on amplicon sequencing of the amoA, which codes for the alpha subunit of ammonia monooxygenase; AMO), show that their habitats are believed to range from marine to terrestrial environments. However, the mechanisms of adaptation underpinning to their habitat expansion remain poorly understood. Here, we report that AOA accounts for almost all of the ammonia oxidizers in the shelf water adjacent to the Pearl River estuary (PRE), with the Nitrosopumilusmaritimus SCM1-like (SCM1-like) being the main amoA genotype. Using a metagenomic approach, seven high-quality AOA genomes were reconstructed from the PRE. Phylogenetic analysis indicated that four of these genomes with high completeness were closely affiliated with the Nitrosomatrinuscatalina strain SPOT01, which was originally isolated off the coast of California. Genomic comparison revealed that the PRE AOA genomes encoded genes functioning in amino acid synthesis, xenobiotic biodegradation metabolism, and transportation of inorganic phosphate and heavy metals. This illustrates the different adaptations of AOA in one of the largest estuaries in China, which is strongly influenced by anthropogenic input. Overall, this study provides additional genomic information about estuarine AOA, and highlights the importance of their contribution to nitrification in eutrophic coastal environments.
A diagram of the metabolic mechanism of ammonia-oxidizing archaea in the Pearl River Estuary
