Planctobacteria - AbsoluteAstronomy.com

Planctobacteria is a taxon

Taxon

|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

created by Cavalier-Smith, specifically a division (phylum

Phylum

In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....

)Historically bacteria were considered plants consequently the usage of "division" over "phylum" was brought over when the kindgom Monera

Monera

Monera is a superseded kingdom that contains unicellular organisms without a nucleus , such as bacteria....

was established. The bacteriological code has since imposed that the rank should be phylum and not division. Nevertheless, Cavalier-Smith adopts the term division., it is however not followed by the larger scientific community.

Cavalier-Smith postulated that the Planctobacteria probably lost or reduced their peptidoglycan

Peptidoglycan

Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria , forming the cell wall. The sugar component consists of alternating residues of β- linked N-acetylglucosamine and N-acetylmuramic acid...

cell wall

Cell wall

The cell wall is the tough, usually flexible but sometimes fairly rigid layer that surrounds some types of cells. It is located outside the cell membrane and provides these cells with structural support and protection, and also acts as a filtering mechanism. A major function of the cell wall is to...

twice.

In the Cavalier-Smith bacterial megaclassification, it is within the bacterial Gracilicutes

Gracilicutes

Gracilicutes is a controversial taxon in Bacterial taxonomy.Traditionally Gram staining results were most commonly used as a classification tool, consequently until the advent of molecular phylogeny, the Kingdom Prokaryotae was divided into four divisions,*...

infrakindgom and comprises three classes Chlamydiae

Chlamydiae

Chlamydiae is a bacterial phylum and class whose members are obligate intracellular pathogens. Many Chlamydiae coexist in an asymptomatic state within specific hosts, and it is widely believed that these hosts provide a natural reservoir for these species....

, Lentisphaerae

Lentisphaerae

Lentisphaerae is a phylum of bacteria closely related to Chlamydiae and Verrucomicrobia.It includes two monotypic orders Lentisphaerales and Victivallales. Phylum members can be aerobic or anaerobic and fall under two distinct phenotypes. One consists of terrestrial gut microbiota from mammals...

, Planctomycetes

Planctomycetes

Planctomycetes are a phylum of aquatic bacteria and are found in samples of brackish, and marine and fresh water. They reproduce by budding. In structure, the organisms of this group are ovoid and have a holdfast, called the stalk, at the nonreproductive end that helps them to attach to each other...

, Verrucomicrobia

Verrucomicrobia

Verrucomicrobia is a recently described phylum of bacteria. This phylum contains only a few described species . The species identified have been isolated from fresh water and soil environments and human feces...