Pseudomonas putida

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Scientific classification
Kingdom: Eubacteria
Phylum: Proteobacteria
Class: Gamma Proteobacteria
Order: Pseudomonadales
Family: Pseudomonadaceae
Genus: Pseudomonas
Species: putida
Binomial name
Pseudomonas putida

Description and significance

Pseudomonas putida are Gram-negative rod-shaped bacteria. They normally dwell in moist soil environments. Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced. Describe how and where it was isolated. Include a picture or two (with sources) if you can find them.

Genome structure

The genome of Pseudomonas putida was sequenced due to the many unique abilities that this bacterium possesses. Scientists are interested in which genes cause what function. So far, P. putida has the most genes of any microorganism that break down chemicals such as aromatic hydrocarbons. Research is being done on the difference in genome of P. putida and its relative Pseudomonas aeruginos in relation to cystic fibrosis. While P. aeruginos infects and kills those with the disease, P. putida lacks the genes that causes such destruction, like the genes that code for enzymes that digest cell membranes. The Pseudomonas putida strain KT2440 genome was sequenced as a joint project between The Institute for Genomic Research and a German consortium in 1999. The way that they sequenced the genome was using the random shotgun method. They found that the one circular chromosome contains 6,181,863 base pairs. The total number of genes is 5,516, with 5,421 being protein coding. The total number of repeats, or stretches greater than 200 base pairs and almost identical, was 398. Interestingly, there was a high GC content in the genome, which created some difficulty in sequencing through the traditional methods. Through sequencing the Pseudomonas putida genome, scientists were able to determine the biotechnological potential of the organism. Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?

Cell structure and metabolism

Pseudomonas putida are aerobic, non sporeforming, oxidase positive bacteria. Having one or more polar flagella, they are motile organisms. They can be found in moist environments, such as soil and water, and grow optimally at room temperature. P. putida are unique saprobes in that use a wide variety of non-living material as their source of nutrition, including multiple types of aromatic hydrocarbons [[1]]. This allows them to be agents of bioremediation, one of the most differentiating and impressive features of Pseudomonas putida. Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.

Ecology

Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.

Pathology

In genetic terms, Pseudomonas putida is very similar to strains of Pseudomonas aeroginosa, an opportunistic human pathogen. Although there is a considerable amount of genome conservation, P. putida seems to be missing the key virulent segments that P. aeroginosa has. Being a non-pathogenic bacteria, there has been only a handful of episodes where P. putida has infected humans. For the most part, it has been with immunocompromised patients, causing septicaemia, septic arthritis, or peritonitis. P. putida is also closely related to Pseudomonas syringae, an abundant plant pathogen, but again it lacks the gene that causes such disease. How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

Application to Biotechnology

Pseudomonas putida is being used in conjunction with Escherichia coli for developing new drugs. This study focuses on myxochromide S, a compound produced by Stigmatella aurantiaca, but the method is revolutionary in that there is unprecedented expression of gene clusters. The beginnings of many new drugs are from natural sources, such as plants and microorganisms, but they are too expensive to harvest from the origin. Combinatorial biosynthesis has revolutionized drug development by allowing the structure of certain molecules to be changed within an organism. With this metabolic engineering, where genes are introduced and their expressions are tightly controlled, successful production of drugs is possible. Pseudomonas putida is unique in that it allows the expression of a large biosynthetic cluster, producing five times as much myxochromide S as Stigmatella aurantiaca. This will also permit scientists to connect multiple clusters of genes onto a single DNA fragment. Does this organism produce any useful compounds or enzymes? What are they and how are they used?

Current Research

Enter summaries of the most recent research here--at least three required

References