Planctomycetaceae is the only family in the order Planctomycetales within the

Bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

. Species within this family are mostly spherical, inhabiting a vast array of aquatic environments with the majority being in marine ecosystems. ''Planctomycetaceae'' species are generally aerobic, but are uniquely classified by fatty acid synthesis and stalk-like formations.

Morphology

When compared to other species of the order ''Planctomycetales'', species of the ''Planctomycetaceae'' family have very few unique characteristics that can taxonomically distinguish them from other related families''. Planctomycetaceae'' species typically form colonies of a pink or white hue. Their cell structure has been recorded to be spherical, but many species are elliptical or pear-shaped; all species range from 0.4 micrometers to 2.5 micrometers in size. When reproducing, cell structures of ''Planctomycetaceae'' are usually observed to be in either a rosette or aggregate grouping; the species ''Thalassoglobus neptunius'' is the only known example in this family capable of growing in chains. Some members of ''Planctomycetaceae'' (including other taxonomic groups of ''Planctomycetota'') develop stalk-like projections. The species ''Planctomyces bekefii'' is well-known in this family for its stalks, using them to connect newly produced cells.

Physiology

Families in ''Planctomycetales'' that have more research conducted have been noted to undergo anaerobic respiration, with the family ''Brocadiaceae'' being well known for its anaerobic ammonium redox (anammox) capabilities. ''Planctomycetaceae'' is one of the many families of ''Planctomycetales'' that is both aerobic and cannot do anammox reactions. Similar to other families, members of ''Planctomycetaceae'' are capable of motility using flagella with some having cycles of motile and immotile lifestyles. Standing out from other bacteria, this group has been able to utilize its stalk-like structures to aid in biofilm production, providing a second source of adherence than usual extracellular polymeric substances. Fatty acids and lipids synthesized by ''Planctomycetaceae'' are similar in composition to other families of the order ''Planctomycetales'', but are unique enough to be considered taxonomically critical. Phosphocholine, phosphatidylcholine, and phosphatidylglycerol are considered the major lipids of this family, which only some other families are capable of synthesizing. Most notably, fatty acid C_18:1-ω9C is synthesized only within this family of Planctomycete bacteria.

Phylogeny

The currently accepted taxonomy is based on the

List of Prokaryotic names with Standing in Nomenclature List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclatu ...

(LPSN) and

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is lo ...

(NCBI). As of 2022, researchers have discovered that there are currently 14 genera and 29 species within ''Planctomycetaceae.'' Genera incertae sedis: * '' Planctomyces'' Gimesi 1924 * '' Planctellipticum'' corrig. Wurzbacher et al. 2024 * "'' Rhodopilula''" Frank 2011 * "'' Thermopirellula''" Liu et al. 2012

References

{{Taxonbar, from1=Q131798, from2=Q18674592 Planctomycetota Bacteria families

Morphology

Physiology

Phylogeny

See also

References