|Families & Genera|
Planctomycetes are a ovoid and have a holdfast, at the tip of a thin cylindrical extension from the cell body called the stalk, at the nonreproductive end that helps them to attach to each other during budding.
- Structure 1
- Genome 2
- Life cycle 3
- Phylogeny 4
- References 5
- External links 6
For a long time bacteria belonging to this group were considered to lack peptidoglycan, (also called murein) in their cell walls, which is an important heteropolymer present in most bacterial cell walls that serves as a protective component. It was thought that instead their walls were made up of glycoprotein which is rich in glutamate. Recently, however, representatives of all three clades within the Planctomycetes were found to possess peptidoglycan containing cell walls.
Planctomycetes have a distinctive morphology with the appearance of membrane-bound internal compartments, often referred to as the paryphoplasm (ribosome-free space), pirellulosome (ribosome-containing space) and nucleoid (condensed nucleic acid region, in these species surrounded by a double membrane). Until the discovery of the Poribacteria, planctomycetes were the only bacteria known with these apparent internal compartments. Three-dimensional electron tomography reconstruction of a representative species, Gemmata obscuriglobus, has yielded varying interpretations of this observation. One 2013 study found the appearance of internal compartments to be due to a densely invaginated but continuous single membrane, concluding that only the two compartments typical of Gram-negative bacteria - the cytoplasm and periplasm - are present. However, the excess membrane triples the surface area of the cell relative to its volume, which may be related to Gemmata's sterol biosynthesis abilities. A 2014 study using similar methods reported confirmation of the earlier enclosed compartment hypothesis.
It has recently been shown that Gemmata obscuriglobus is able to take in large molecules via a process which in some ways resembles endocytosis, the process used by eukaryotic cells to engulf external items.
operons, which is unusual for bacteria. A number of genes have been found (through sequence comparisons) that are similar to genes found in eukaryotes. One such example is a gene sequence (in Gemmata obscuriglobus) that was found to have significant homology to the integrin alpha-V, a protein that is important in transmembrane signal transduction in eukaryotes.
The life cycle of many planctomycetes involves alternation between sessile cells and flagellated swarmer cells. The sessile cells bud to form the flagellated swarmer cells which swim for a while before settling down to attach and begin reproduction.
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LSPN)  and the phylogeny is based on 16S rRNA-based LTP release 111 by The All-Species Living Tree Project 
♠ Strains found at the National Center for Biotechnology Information (NCBI) but not listed in the List of Prokaryotic names with Standing in Nomenclature (LSPN)
♪ Prokaryotes where no pure (axenic) cultures are isolated or available, i. e. not cultivated or can not be sustained in culture for more than a few serial passages
- Jeske, O., Schueler, M., Schumann, P., Schneider, A., Boedeker, C., Jogler, M., Bollschweiler, D., Rohde, M., Mayer, C., Engelhardt, H., Spring, S. & Jogler, C. (2015). "Planctomycetes do possess a peptidoglycan cell wall". Nature communications 6.
- van Teeseling, M.C.F., Mesman, R.J., Kuru, E., Espaillat, A., Cava, F., Brun, Y.V., VanNieuwenhze, M.S., Kartal, B & van Niftrik, L. (2015). "Anammox Planctomycetes have a peptidoglycan cell wall". Nature communications 6.
- Lindsay, M. R.; Webb, R. I.; Strous, M; Jetten, M. S.; Butler, M. K.; Forde, R. J.; Fuerst, J. A. (2001). "Cell compartmentalisation in planctomycetes: Novel types of structural organisation for the bacterial cell". Archives of microbiology 175 (6): 413–29.
- Glöckner, F. O.; Kube, M; Bauer, M; Teeling, H; Lombardot, T; Ludwig, W; Gade, D; Beck, A; Borzym, K; Heitmann, K; Rabus, R; Schlesner, H; Amann, R; Reinhardt, R (2003). "Complete genome sequence of the marine planctomycete Pirellula sp. Strain 1". Proceedings of the National Academy of Sciences 100 (14): 8298–303.
- Fieseler, L; Horn, M; Wagner, M; Hentschel, U (June 2004). "Discovery of the novel candidate phylum "Poribacteria" in marine sponges.". Applied and environmental microbiology 70 (6): 3724–32.
- Santarella-Mellwig, R., Pruggnaller, S., Roos, N., Mattaj, I., & Devos, D. (2013). "Three-Dimensional Reconstruction of Bacteria with a Complex Endomembrane System". PLoS Biology 11.
- Sagulenko, E; Morgan, G. P.; Webb, R. I.; Yee, B; Lee, K. C.; Fuerst, J. A. (2014). "Structural studies of planctomycete Gemmata obscuriglobus support cell compartmentalisation in a bacterium". PLoS ONE 9 (3): e91344.
- Lonhienne, Thierry G. A.; Sagulenko, Evgeny; Webb, Richard I.; Lee, Kuo-Chang; Franke, Josef; Devos, Damien P.; Nouwens, Amanda; Carroll, Bernard J. & Fuerst, John A. (2010). "Gemmata obscuriglobus"Endocytosis-like protein uptake in the bacterium . Proceedings of the National Academy of Sciences 107 (29): 12883–12888.
- Williams, Caroline (2011). "Who are you calling simple?". New Scientist 211 (2821): 38–41.
- Hou S., Makarova K.S., Saw J.H., Senin P., Ly B.V., Zhou Z., Ren Y., Wang J., Galperin M.Y., Omelchenko M.V., Wolf Y.I., Yutin N., Koonin E.V., Stott M.B., Mountain B.W., Crowe M.A., Smirnova A.V., Dunfield P.F., Feng L., Wang L., Alam M. 2008 Complete genome sequence of the extremely acidophilic methanotroph isolate V4, Methylacidiphilum infernorum, a representative of the bacterial phylum Verrucomicrobia. Biol. Direct. 3(1):26.
- F. O. Glöckner, M. Kube, M. Bauer, H. Teeling, T. Lombardot, W. Ludwig, D. Gade, A. Beck, K. Borzym, K. Heitmann, R. Rabus, H. Schlesner, R. Amann, and R. Reinhardt (2003) Complete genome sequence of the marine planctomycete Pirellula sp. strain 1 PNAS 100:14 8298-8303 doi=10.1073/pnas.1431443100 pmid= 12835416 pmc=166223
- Cheryl Jenkins, Vishram Kedar, and John A. Fuerst (2002) Gene discovery within the planctomycete division of the domain Bacteria Genome Biology 3:6 1-11
- See the
- See the
- Beyond Prokaryotes and Eukaryotes : Planctomycetes and Cell Organization.
- Gemmata at Microbewiki