The only existing complete genomes available from marine ammonia-oxidizing archaea (AOA) were isolated from a tropical aquarium and the other an obligate sponge symbiont. Although the genomes of these organisms have been extremely valuable to the field, neither organism is truly representative of abundant planktonic (water column) AOA found in the ocean. Studies suggest there are there are two distinct groups of “water column AOA.” The first group is primarily found in the upper ocean and thought to represent a “shallow” ecotype, while the second group appears to represent a “deep” ecotype, whose abundance increases considerably with depth below 200 meters in the ocean. Through metagenomics and single-cell genomics, researchers hope to fill in gaps of knowledge about these AOA communities.
PI: Christopher Francis, Stanford University