Diversity, metabolism and cultivation of archaea in mangrove ecosystems

Mangroves comprise a globally significant intertidal ecosystem that contains a high diversity of microorganisms, including fungi, bacteria and archaea. Archaea is a major domain of life that plays important roles in biogeochemical cycles in these ecosystems. In this review, the potential roles of archaea in mangroves are briefly highlighted. Then, the diversity and metabolism of archaeal community of mangrove ecosystems across the world are summarized and Bathyarchaeota, Euryarchaeota, Thaumarchaeota, Woesearchaeota, and Lokiarchaeota are confirmed as the most abundant and ubiquitous archaeal groups. The metabolic potential of these archaeal groups indicates their important ecological function in carbon, nitrogen and sulfur cycling. Finally, some cultivation strategies that could be applied to uncultivated archaeal lineages from mangrove wetlands are suggested, including refinements to traditional cultivation methods based on genomic and transcriptomic information, and numerous innovative cultivation techniques such as single-cell isolation and high-throughput culturing (HTC). These cultivation strategies provide more opportunities to obtain previously uncultured archaea.