The ''Pectobacteriaceae'' are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Gram-negative bacteria Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the Crystal violet, crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelo ...

which largely consist of plant pathogens. This family is a member of the order

Enterobacterales Enterobacterales is an order of Gram-negative bacteria, Gram-negative, non-spore forming, Facultative anaerobic organism, facultatively anaerobic, rod-shaped bacteria with the class Gammaproteobacteria. The type genus of this order is ''Enterob ...

in the class

Gammaproteobacteria ''Gammaproteobacteria'' is a class of bacteria in the phylum ''Pseudomonadota'' (synonym ''Proteobacteria''). It contains about 250 genera, which makes it the most genus-rich taxon of the Prokaryotes. Several medically, ecologically, and scienti ...

of the phylum

Pseudomonadota Pseudomonadota (synonym "Proteobacteria") is a major phylum of gram-negative bacteria. Currently, they are considered the predominant phylum within the domain of bacteria. They are naturally found as pathogenic and free-living (non- parasitic) ...

. The type species of this family is '' Pectobacterium''. The name ''Pectobacteriaceae'' is derived from the Latin term ''Pectobacterium'', referring the type genus of the family and the suffix "-aceae", an ending used to denote a family. Together, ''Pectobacteriaceae'' refers to a family whose nomenclatural type is the genus ''Pectobacterium''.

Biochemical Characteristics and Molecular Signatures

Source: Members of the family produce acid from N-acetylglucosamine and are negative for arginine dihydrolase, orthinine decarboxylase and lysine decarboxylase. These bacteria are catalase-positive, oxidase-negative, and do not produce hydrogen disulfide. Genomic analyses identified four

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 specific this family in the proteins transcriptional activator RhaS, flagellar motor protein MotB, a two-component sensor

histidine kinase Histidine kinases (HK) are multifunctional, and in non-animal kingdoms, typically transmembrane, proteins of the transferase class of enzymes that play a role in signal transduction across the cellular membrane. The vast majority of HKs are ho ...

protein and a hypothetical protein. These molecular signatures provide a reliable molecular means for distinguishing members of the family ''Pectobacteriaceae'' from other families in the order ''Enterobacterales'' and other bacteria.

Historical Systematics and Current Taxonomy

''Pectobacteriaceae'', as of 2021, contains eight validly published genera. Members of this family were originally members of the ''

Enterobacteriaceae Enterobacteriaceae is a large family (biology), family of Gram-negative bacteria. It includes over 30 genera and more than 100 species. Its classification above the level of Family (taxonomy), family is still a subject of debate, but one class ...

family'', a large phylogenetically unrelated group of species with distinct biochemical characteristics and different ecological niches. The original assignment of species into the family ''Enterobacteriaceae'' was largely based on 16S rRNA genome sequence analyses, which is known to have low discriminatory power and the results of which changes depends on the algorithm and organism information used. Despite this, the analyses still exhibited polyphyletic branching, indicating the presence of distinct subgroups within the family. In 2016, Adeolu et al. proposed the division of ''Enterobacteriaceae'' into 7 novel families based on comparative genomic analyses and the branching pattern of various phylogenetic trees constructed from conserved genome sequences, 16S rRNA sequences and multilocus sequence analyses. Molecular markers, specifically

, specific to this family were also identified as evidence supporting the division independent of phylogenetic trees.

References

Gram-negative bacteria Enterobacterales Pectobacteriaceae {{gammaproteobacteria-stub