Is Erwinia Gram positive or negative?

Is Erwinia Gram positive or negative?

Erwinia amylovora, a Gram negative bacteria of the Enterobacteriaceae family, is the causal agent of fire blight, a devastating plant disease affecting a wide range of host species within Rosaceae and a major global threat to commercial apple and pear production.

What causes Erwinia carotovora?

The bacterial soft rot is caused by Erwinia carotovora p.v. carotovora, a common problem in many vegetables especially during storage. It usually develops in onions after heavy rains or after irrigation with contaminated water. This disease is primarily a problem on mature onion bulbs during warm humid conditions.

How is Erwinia carotovora treated?

There are no compounds that can rid infected plants of Erwinia; although, bactericides containing copper can help slow the spread of the pathogen. Antibiotics have been recommended, but the bacteria adapt and populations become resistant within a matter of weeks.

What enzyme is produced by bacterium Erwinia?

Extracellular Enzymes

Does Erwinia produce endospores?

Spores: None. Other: They occur singly or in pairs and sometimes in short chains.

Is Erwinia citrate positive or negative?

Biochemical tests. The genus Erwinia has been defined as Gram-negative bacteria, facultative anaerobes, motile by peritrichous flagella, rod-shaped, acid produced from glucose, fructose, galactose and sucrose.

What are the 3 factors needed in order for a plant disease to occur?

Plant diseases– their occurrence and severity– result from the impact of three factors: the host plant, the pathogen, and the environmental conditions. This is represented with the disease triangle. If any one of the three factors is missing, the triangle is not complete, no disease will occur.

Is Erwinia a lactose fermenter?

Wild-type strains of the phytopathogenic enterobacterium Erwinia chrysanthemi are unable to use lactose as a carbon source for growth although they possess a beta-galactosidase activity. Lactose-fermenting derivatives from some wild types, however, can be obtained spontaneously at a frequency of about 5 X 10(-7).

How does Erwinia carotovora kill cells?

(1) Erwinia carotovora is a plant pathogen that causes cell death through plant cell wall destruction by creating an osmotically fragile cell. This is achieved through the production of PCWDEs (3) such as extracellular pectic enzymes and cellulase that break down pectin and cellulose, respectively.

What is the microscopic appearance of Erwinia spp?

MICROSCOPIC APPEARANCE Gram Stains: Gram-negative. Morphology: Straight rods. Size: 0.5-1.0 micrometer by 1.0-3.0 micrometer Motility: Erwinia spp. are motile by peritrichous Capsules: None.

What is Erwinia uredovora?

Erwinia uredovora is a parasite of rust fungi and multiples in the plant tissue infected by the rust organism. Strains of E. herbicola are common in the epiphytic microflora of plants; instances have been reported in which E. herbicola has produced symptoms on plants, sometimes possibly in association with other phytopathogenic bacteria. (2)

What are the diseases caused by Erwinia?

Erwinia species cause plant diseases which include blights, cankers, die back, leaf spots, wilts, discoloration of plant tissues, and sot rots variously described as stalk rot, crown rot, stem rot, or fruit collapse.