''Planococcus'' is a genus of

Gram-Positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bac ...

or Gram-variable, cocci or short rod-shaped bacteria in the family ''

Caryophanaceae The ''Caryophanaceae'' is a family of Gram-positive bacteria. In 2020, the now defunct family ''Planococcaceae'' was merged into ''Caryophanaceae'' to rectify a nomenclature anomaly. The type genus of this family is '' Caryophanon.'' The family ...

'' from the order Caryophanales''.'' The type species of this genus is ''Planococcus citreus.'' Some members of ''Planococcus'' are previously species belonging to ''Planomicrobium.'' Instead of branching with species from ''Planomicrobum'', these species formed a monophyletic branch with members of ''Planococcus'' in various phylogenetic trees constructed based on conserved genome sequences, indicating their phylogenetic relatedness. The family ''

'' encompassed many branching anomalies such as this one, partially due to the reliance on 16S rRNA sequences as a method for classification, which is known to have low resolution power and give differing results depending on the algorithm used. In 2020, a comparative genomic study emended the family, resulting in the establishment of three new genera as well as the amendment of a number of genera including ''Planococcus''. The name ''Planococcus'' is derived from the Greek noun ''planes'', translating into "a wanderer" and the Latin term ''coccus.'' Together, ''Planococcus'' can be translated as a motile coccus.

Biochemical Characteristics and Molecular Signatures

Cells exhibit

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bac ...

or Gram-variable staining and they are cocci or short rods and generally motile. Genomic analyses identified five

conserved signature indels Conserved signature inserts and deletions (CSIs) in protein sequences provide an important category of molecular markers for understanding phylogenetic relationships. CSIs, brought about by rare genetic changes, provide useful phylogenetic markers ...

(CSIs) that are uniquely present in members of this genus in the following proteins : penicillin-binding protein 2, hypothetical protein, NADPH-dependent 7-cyano-7-deazaguanine reductase QueF, ACT domain-containing protein, and

methylmalonyl-CoA mutase Methylmalonyl-CoA mutase (, MCM), mitochondrial, also known as methylmalonyl-CoA isomerase, is a protein that in humans is encoded by the ''MUT'' gene. This vitamin B12-dependent enzyme catalyzes the isomerization of methylmalonyl-CoA to succiny ...

. These molecular signatures provide a reliable method for differentiating ''Planococcus'' species from other genera within the family ''Caryophanaceae'' and all other bacteria.

Taxonomy

''Planococcus'', as of 2021, contains 24 species with validly published names. This genus was identified as a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...

clade and phylogenetically unrelated to other species in the family ''Caryophanaceae'' in studies examining the taxonomic relationships within the family.

References

{{reflist Bacillales Bacteria genera