[5] They play a considerable role in global carbon and nitrogen cycles, with many species of this phylum capable of anaerobic ammonium oxidation, also known as anammox.

[5][6] Many Planctomycetota occur in relatively high abundance as biofilms,[7] often associating with other organisms such as macroalgae and marine sponges.

The species Gemmata obscuriglobus has been identified specifically as comprising bacteria with unique characteristics among the Planctomycetota,[15][16] such as their ability to synthesize sterols.

[18] Early examination of the Planctomycetota suggested that their cell plan differed considerably from both Gram-positive and Gram-negative bacteria.

Peptidoglycan is an essential polymer of glycans, present in all free-living bacteria, and its rigidity helps maintain integrity of the cell.

The excess membrane observed in G. obscuriglobus triples the surface area of the cell relative to its volume, which is suggested to be associated with sterol synthesis.

[16] Many Planctomycetota species display pink or orange coloring, suggested to result from the production of carotenoid pigments.

[19] In marine environments, Planctomycetota are often suspended in the water column or present as biofilms on the surface of macroalgae, and are often exposed to harmful ultraviolet radiation.

[15] The dominant form of reproduction observed in almost all bacteria is cell division by binary fission, which involves the synthesis of both peptidoglycans and proteins known as FtsZ.

[12][13] Planctomycetota are known for their unusual cellular characteristics, and their distinctness from all other bacteria is additionally supported by the shared presence of two conserved signature indels (CSIs).

[9] When comparing under a microscope, a defining characteristic for some Planctomycetota is that a single unlinked rRNA operon can be identified near the origin.

This creates a way of diversification in the Planctomycetota variants as multiple transposon genes in these regions have reverse orientation that transfers to rearrangements.

Some Planctomycetota thrive in regions containing highly concentrated nitrate,[6] and have genes that are required for heterotactic acid fermentation.

In comparison with a different species of prokaryotic, Pseudomonas aeruginosa, only 6 sulfatases occur and the genes that express these proteins are contained as two to five pairs, usually clustered in 22 groups.

[31] Originally classified as a eukaryote due to morphology, the advent of genetic sequencing allowed researchers to agree that the Planctomycetota belong to the domain Bacteria.

Both the Planctomycetota and Chlamydiota encode proteins for nucleotide transporters, and the Verrucomicrobiota have also been found to have features common among eukaryotic cells.

[9] Sedimentisphaerales Tepidisphaerales Phycisphaerales Gemmatales Isosphaerales Planctomycetales Pirellulales "Uabimicrobiales" "Brocadiales" Sedimentisphaerales Tepidisphaerales Phycisphaerales Gemmatales Isosphaerales Planctomycetales Pirellulales Members of the Planctomycetota are found in a diverse range of environments, both geographically and ecologically,[39] and occur in both aquatic and terrestrial habitats.

[9] Planctomycetota account for roughly 11% of prokaryotic communities in marine systems, and their vast distribution demonstrates their ability to inhabit many different environments.

Thermostilla marina, a thermophilic anaerobic species occupying hydrothermal vent regions, can use elemental sulfur to generate sulfide and respire with nitrate.

[8] Planctomycetota have a significant impact on global biogeochemistry and climate, with their ability to mineralize and break down detritus particles in the water column.

This ability to recycle carbon has been linked to specific C1 metabolism genes observed in many Planctomycetota and are suggested to play a significant role, but this area of research is still poorly understood.

[42] Planctomycetota have often been observed in association with many organisms, including, macroalgae, microalgae, marine sponges, and plants such as lichens and bryophytes.

[8] Kelp forests dominate the rocky coastlines of temperate regions, and provide habitat, shelter, and food for many organisms, including the Planctomycetota.

[44] Planctomycetota also play an important role as components of detritus in the water column, also known as marine snow,[5][44] given their ability to attach to surfaces.

The seaweed Caulerpa taxifolia was incubated under higher CO2 conditions, and the abundance of Planctomycetota increased substantially, as much as 10 times in some species.

[18] In addition, with the use of cryoelectron tomography-based three-dimensional reconstruction of Planctomycetota has found that what were originally thought to be vesicles being held in the periplasm are actually just folds in the cytoplasmic membrane.

Three hypotheses have been put forth: First, the Planctomycetota excrete an enzyme which, outside of the cell wall, degrades the complex substrates into smaller monosaccharides, which can more easily be transported through the different membranes.

Planctomycetota are unique in that they have large invaginations of their cytoplasmic membrane, pulling away from the peptidoglycan cell wall and leaving room for the periplasm.

Sterol synthesis is suggested to be associated with regulation of membrane fluidity in Planctomycetota,[15] and has been described as essential to the proper growth and reproduction of G.

However, with Planctomycetota's growing influences on metabolic processes involving water and air, it may also have a role in interchanges between oceans and atmosphere, potentially affecting climate change.