Erwinia
Encyclopedia
Erwinia is a genus of Enterobacteriaceae
bacteria containing mostly plant
pathogen
ic 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) 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.
, 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, xylanase
s and nucleases (along with the normal virulence factors for pathogens – Fe acquisition, LPS integrity, multiple global regulatory systems).
Enterobacteriaceae
The Enterobacteriaceae is a large family of bacteria that includes many of the more familiar pathogens, such as Salmonella, Escherichia coli, Yersinia pestis, Klebsiella and Shigella. This family is the only representative in the order Enterobacteriales of the class Gammaproteobacteria in the...
bacteria containing mostly plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
ic species which was named for the first phytobacteriologist, Erwin Smith. It is a gram negative bacterium related to E. coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
, Shigella
Shigella
Shigella is a genus of Gram-negative, nonspore forming, non-motile, rod-shaped bacteria closely related to Escherichia coli and Salmonella. The causative agent of human shigellosis, Shigella causes disease in primates, but not in other mammals. It is only naturally found in humans and apes. During...
, Salmonella
Salmonella
Salmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...
and Yersinia
Yersinia
Yersinia is a genus of bacteria in the family Enterobacteriaceae. Yersinia are Gram-negative rod shaped bacteria, a few micrometers long and fractions of a micrometer in diameter, and are facultative anaerobes. Some members of Yersinia are pathogenic in humans; in particular, Y. pestis is the...
. It is primarily a rod-shaped bacteria. A well-known member of this genus is the species E. amylovora, which causes fireblight
Fireblight
Fire blight, also written fireblight, is a contagious disease affecting apples, pears, and some other members of the family Rosaceae. It is a serious concern to producers of apples and pears...
on apple, pear, and other Rosaceous crops. Erwinia carotovora (also known as Pectobacterium carotovorum) 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 lossesPostharvest losses
The postharvest sector includes all points in the value chain from production in the field to the food being placed on a plate for consumption. Postharvest activities include: Harvesting, handling, storage, processing, packaging, transportation and marketing...
, 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, xylanase
Xylanase
Xylanase is the name given to a class of enzymes which degrade the linear polysaccharide beta-1,4-xylan into xylose, thus breaking down hemicellulose, one of the major components of plant cell walls....
s and nucleases (along with the normal virulence factors for pathogens – Fe acquisition, LPS integrity, multiple global regulatory systems).