The ''Pectobacteriaceae'' are a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Gram-negative bacteria Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

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

Enterobacterales Enterobacterales is an order of Gram-negative, non-spore forming, facultatively anaerobic, rod-shaped bacteria with the class Gammaproteobacteria. The type genus of this order is '' Enterobacter.'' The name Enterobacterales is derived from th ...

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 genera-rich taxon of the Prokaryotes. Several medically, ecologically, and scientifically imp ...

of the phylum

Pseudomonadota Pseudomonadota (synonym Proteobacteria) is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The ...

. The type species of this family is ''

Pectobacterium ''Pectobacterium'' is a bacterial genus of the family Pectobacteriaceae; it used to be a member of the genus ''Erwinia'', which was split into three genera: ''Erwinia'', ''Pectobacterium'', and ''Brenneria''. Species include ''Pectobacterium c ...

''. 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

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 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 family ''

Enterobacteriaceae Enterobacteriaceae is a large family of Gram-negative bacteria. It was first proposed by Rahn in 1936, and now includes over 30 genera and more than 100 species. Its classification above the level of family is still a subject of debate, but on ...

'', 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

Pectobacteriaceae

Gram-negative bacteria Enterobacterales {{gammaproteobacteria-stub