Erwinia

Erwinia
Scientific classification
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Gamma Proteobacteria
Order:	Enterobacteriales
Family:	Enterobacteriaceae
Genus:	Erwinia Winslow et al. 1920
Type species
Erwinia amylovora NCPPB 683
Species
Erwinia amylovora Erwinia aphidicola Erwinia billingiae Erwinia carotovora (now called Pectobacterium carotovorum) Erwinia chrysanthemi Erwinia mallotivora Erwinia papayae Erwinia persicina Erwinia psidii Erwinia pyrifoliae Erwinia rhapontici Erwinia toletana Erwinia tracheiphila Candidatus Erwinia dacicola

Erwinia is a genus of Enterobacteriaceae bacteria containing mostly plant pathogenic species which was named for the first phytobacteriologist, Erwin Smith. It is a gram negative bacterium related to E. coli, Shigella, Salmonella and Yersinia. It is primarily a rod-shaped bacteria. A well-known member of this genus is the species E. amylovora, which causes fireblight on apple, pear, and other Rosaceous crops. Erwinia carotovora (also known as Pectobacterium carotovorum)^{[citation needed]} is another species, which causes diseases in many plants. These species produce pectolytic enzymes that hydrolyze pectin between individual plant cells. This causes the cells to separate, a disease plant pathologists term bacterial soft rot.

Erwinia carotovora (Pectobacterium carotovorum)

This bacteria is a ubiquitous plant pathogen with a wide host range (carrot, potato, tomato, leafy greens, squash and other cucurbits, onion, green peppers, etc.), able to cause disease in almost any plant tissue it invades. It is a very economically important pathogen in terms of postharvest losses, and a common cause of decay in stored fruits and vegetables. Decay caused by E. carotovora is often referred to as bacterial soft rot (BSR). Most plants or plant parts can resist invasion by the bacteria, unless some type of wound is present. High humidity and temperatures around 30°C favor development of decay. Mutants can be produced which are less virulent. Virulence factors include: pectinases, cellulases, (which degrade plant cell walls), and also proteases, lipases, xylanases and nucleases (along with the normal virulence factors for pathogens – Fe acquisition, LPS integrity, multiple global regulatory systems).