Erwinia carotovora
A Microbial Biorealm page on the genus Erwinia carotovora
Classification
Higher order taxa
Kingdom: Bacteria Phylum: Proteobacteria Class: Gammaproteobacteria Order: Enterobacteriales Family: Enterobacteriaceae Genus: Erwinia Species: carotovora
Species
Erwinia amylovora; Erwinia aphidicola; Erwinia billingiae; Erwinia carotovora; Erwinia chrysantum; Erwinia mallotivora; Erwinia papayae; Erwinia persicina; Erwinia psidii; Erwinia pyrifoliae; Erwinia rhapontici; Erwinia toletana; Erwinia tracheiphila
Description and significance
Erwinia carotovora is a rod shaped bacterium that was named after the crop of carrots from which it was first isolated. The bacterium infects a variety of vegetables and plants including carrots, potatoes, cucumbers, onions, tomatoes, lettuce and ornamental plants like iris.(2) These widespread microbes can be found in soil, guts of insects, water and suspended aerosols in air.(1) A major problem in agriculture, the microbes ceaselessly invade crops of potatoes and other vegetables in the fields or in storages that cause plant tissues to become soft and watery which eventually turn slimy and foul-smelling.(2) Whereas Erwinia carotovora subsp. atrosepticum’s pathogencity is restricted to potatoes in temperate temperatures, Erwinia carotovora subsp. carotovora infects a much broader host of plants, including potatoes, in warmer climates.(3)
Genome structure
Genome analysis of Erwinia carotovora indicates that this organism not only fixes nitrogen but also catabolize plant-produced opines. Along with all six of the known secretion systems, the chromosome also encodes a sizeable collection of plant cell wall-degrading enzymes such as pectinases. This signifies the bactium's ability produce pathogenicity determinants such as the aforementioned degradative enzymes and avirulence proteins. Disruption of the type IV secretion system affected virulence, which suggests this does not simply reflect an integrated plasmid in the chromosome.
Cell structure and metabolism
Erwinia Carotovora is a Gram-negative, rod-shaped bacterium that lives alone or aggregates into pairs and chains. Non-sporeforming and peritrichously flagellated, it is a facultative anaerobe that is catalase negative and oxidase positive. Erwinia carotovora produces a number of extracellular plant cell wall degrading enzymes such as pectic enzymes that degrade pectin, cellulase that degrades cellulose, hemicellulases, arabanases, cyanoses and a protease. As a mesophilic bacterium, Erwinia carotovora thrives the most in the temperature range between 27 and 30 degrees Celsius.(1) The genome sequencing of Erwinia carotovora subsp. atroseptica indicates that this microbe may not only be capable of nitrogen fixation and opine catabolism, but may also utilize around eighty ATP binding cassette transport systems.(3)
Ecology
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Pathology
Erwinia carotovora is a plant pathogen that causes cell death through plant cell wall destruction by creating an osmotically fragile cell through the production of extracellular pectic enzymes and cellulase that break down integrity of the pectin and degrades cellulose. This organism causes soft-rot diseases of many plants, including potatoes through plant to plant infection, insect to plant infection, soil to plant and water to plant infection.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
In the recent article "Genome sequence of the enterobacterial phytopathogen Erwinia carotovora subsp. atroseptica and characterization of virulence factors.", it was discovered that organism responsible for blackleg and soft-rot disease in potatoes, Erwinia Carotovora, demonstrates unexpected metabolic traits such as nitrogen fixation and opine catabolism. The proportion of genes responsible for the aforementioned features also encoded pathogenic determinants which were possibly aquired through horizontally transfered gene clusters of type IV secretion and polyketide phytotoxin synthesis.
References
Wood, M. 1998. Ubi7-new tool for potato breeders. Agricultural Research/January 1998, pp. 12-13.
Perombelon, Michael CM. The Prokaryotes. Second Edition. p2899- - 2921.
Bell KS, Sebaihia M, Pritchard L, Holden MT, Hyman LJ, Holeva MC, Thomson NR, Bentley SD, Churcher LJ, Mungall K, Atkin R, Bason N, Brooks K, Chillingworth T, Clark K, Doggett J, Fraser A, Hance Z, Hauser H, Jagels K, Moule S, Norbertczak H, Ormond D, Price C, Quail MA, Sanders M, Walker D, Whitehead S, Salmond GP, Birch PR, Parkhill J, Toth IK. "Genome sequence of the enterobacterial phytopathogen Erwinia carotovora subsp. atroseptica and characterization of virulence factors" Proceedings of the National Academy of Sciences of the United States of America 2004 Jul 27;101(30):11105-10. Epub 2004 Jul 19
