Nitrososphaera gargensis

Nitrososphaera gargensis' genome is 2.83 Mb in size with a GC content of 48%, which is much larger than most other ammonia-oxidizing archaea.[3] The organism encodes for 3565 protein genes and 37 RNA genes.[3][6] N. gargensis also contains a CRISPR-Cas type I system able to target viral DNA, gene duplications in its chaperones, and numerous transposase genes.[3]

N. gargensis neighbors Nitrosopumilus maritimus and Nitrososphaera viennensis on the phylogenetic tree.[7] Like Nitrososphaera gargensis, both of these organisms are chemolithoautotrophic ammonia-oxidizers that thrive in hot and humid habitats.[7] Spang et al. elucidated, in 2012, the notable similarities between N. gargensis and N. viennensis through their nitrification ability and PHA (putatively polyhydroxybutyrate) production along with other elements.[3]

The membrane composition of ammonia-oxidizing archaea, specifically through a crenarchaeol isomer, can be used to identify them as an AOA.[4] N. gargensis was the first cultivated organism with the ability to produce a significant quantity of the crenarchaeol isomer.[4] With its ability to synthesize crenarchaeol, N. gargensis allows scientists to expand this synthesis also to the Group I.1b Crenarchaeota.[4] These discoveries indicate that these organisms are significant sources of crenarchaeol in their habitats of thermophilic and terrestrial environments and corroborate the association between AOA and crenarchaeol.[4]

Furthermore, Nitrososphaera gargensis influence as an ammonia-oxidizing archaea expands from land to water since its nitrification ability plays a role in the nitrogen cycles that are present in the ocean.[9] The nitrogen cycle determines the interplay of organisms in marine ecosystems and the activity of the ocean.[9]

Along with influencing the structure of soils and ocean communities, Nitrososphaera gargensis also plays a role in food production.[5] Since nitrogen is required for food production, fertilizers containing nitrogen are used.[5] This leads to pollution that can harm the environment and end up in wastewater.[5] Therefore, researchers are trying to develop ways to remove the nitrogen from the affected areas.[5] Organisms similar to Nitrososphaera gargensis were found to oxidize ammonia in this study, and with this knowledge, the researchers plan on coupling this ability with other processes in the nitrogen cycle in order to remove the form of nitrogen that is polluting the area.[5] Such couplings could occur due to the fact that AOA are not affected by nitrous acid concentrations whereas nitrite-oxidizing bacteria are inhibited by this chemical.[5] In this difference, techniques could be developed to foster deammonification, which is more cost-effective.[5] Overall, in these studies, researchers are trying to find the correct balance in a thermophilic bioreactor in order to eliminate nitrogen.[5]