Serratia liquefaciens: Difference between revisions
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Not much is actually known about <i>Serratia liquefaciens</i>. In fact, up until 1971, it was actually characterized as <i>Enterobacter liquefaciens</i>. After extensive comparison with <i>S. marcescens</i>, <i>E. liquefaciens</i> was determined to be closely related to <i>S. marcescens</i> and the genus was changed to <i>Serratia</i>.[http://www.annualreviews.org/doi/abs/10.1146/annurev.mi.32.100178.001253] | Not much is actually known about <i>Serratia liquefaciens</i>. In fact, up until 1971, it was actually characterized as <i>Enterobacter liquefaciens</i>. After extensive comparison with <i>S. marcescens</i>, <i>E. liquefaciens</i> was determined to be closely related to <i>S. marcescens</i> and the genus was changed to <i>Serratia</i>.[http://www.annualreviews.org/doi/abs/10.1146/annurev.mi.32.100178.001253] | ||
Following the genus change, little can be found regarding <i>S. liquefaciens</i>. However, it has been proven to have certain antifungal properties in a plant’s rhizosphere. [http://www.sciencedirect.com/science/article/pii/S0944501396800140] It is also a pathogenic bacterium that has been associated with severe nosocomial infections. | Following the genus change, little can be found regarding <i>S. liquefaciens</i>. However, it has been proven to have certain antifungal properties in a plant’s rhizosphere. [http://www.sciencedirect.com/science/article/pii/S0944501396800140] It is also a pathogenic bacterium that has been associated with severe nosocomial infections. | ||
==Genome structure== | ==Genome structure== | ||
Revision as of 04:15, 10 May 2012
A Microbial Biorealm page on the genus Serratia liquefaciens
Classification
Higher order taxa [1]
Domain: Bacteria
Phylum: Proteobacteria
Class: Gammaproteobacteria
Order: Enterobacteriales
Family: Enterbacteriaceae
Genus: Serratia
Species
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NCBI: Taxonomy |
Serratia liquefaciens
Description and significance
S. liquefaciens is a straight rod shaped bacterium with a diameter of 0.5-0.8 μm, a length of 0.9-2.0 μm, and Gram negative. Serratia species are usually motile and contain peritrichous flagella. [Bergey’s Manual of Determinative Bacteriology:9th edition p.187]
S. liquefaciens are facultative anaerobes making oxygen inessential to survival. They can inhabit both aerobic and anaerobic environments. Thus, S. liquefaciens is a widespread bacteria found in the environment and capable of colonizing on soil, water, plants, and the digestive tracts of rodents, insects, fish, and humans.[2] However, it must be noted that S. liquefaciens is not a normal component of human fecal flora. [3]
Not much is actually known about Serratia liquefaciens. In fact, up until 1971, it was actually characterized as Enterobacter liquefaciens. After extensive comparison with S. marcescens, E. liquefaciens was determined to be closely related to S. marcescens and the genus was changed to Serratia.[4]
Following the genus change, little can be found regarding S. liquefaciens. However, it has been proven to have certain antifungal properties in a plant’s rhizosphere. [5] It is also a pathogenic bacterium that has been associated with severe nosocomial infections.
Genome structure
Limited information can be found on the genome of Serratia liquefaciens. The entire genome has not been sequenced so the complete size and contents of the genome are unknown along with number of chromosomes. Several partial sequences of 16S ribosomal RNA have been analyzed and are indicated as linear strands.[6] [7] [8] However, the close relative S. marcescens has a single circular chromosome that is signature to many bacterial species. [9] It has also been proven that some bacteria may have multiple circular chromosomes or linear chromosomes and linear plasmids.[10]
Cell structure and metabolism
Serratia liquefaciens has a straight rod structure that is Gram negative. Gram negative organisms have a thinner layer of peptidoglycan surrounded by an inner and outer membrane. Serratia species are usually motile and have peritrichous flagella.
S. liquefaciens is able to ferment glucose and other carbohydrates (i.e. sucrose, D-mannose,D- mannitol, maltose, salicin, and trehalose) as a source of carbon while producing acid as a byproduct. S. liquefaciens also utilizes lysine, ornithine, and hydrolyzes gelatin, as a source of carbon and energy for growth. It can also hydrolyze DNA and reduce nitrate to nitrite –which may be a byproduct of anaerobic respiration and.[Bergey’s 217]
Ecology
S. liquefaciens is commonly found on many plant species and specifically in the rhizosphere. A rhizosphere is a 1mm area of soil that surrounds the root of a plant and is teeming with biological and chemical activity. The biological makeup is influenced by the specific root where a symbiotic relationship forms. The root releases water soluble compounds into the rhizosphere that provides the microorganisms with nutrients. [11] Meanwhile, the microorganisms will benefit the plant in a variety of ways. Serratia species – including S. liquefaciens - are known to have antifungal properties that benefit oilseed rape. The antifungal properties of the genus produce antibiotics, siderophores, and lytic enzymes like chitinase. Furthermore, S. liquefaciens is specifically linked to protection carnation rhizospheres from root cutting.[12]
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Current Research and or Application to Biotechnology
Enter summaries of the most recent research and/or application to biotechnology here--at least three required
References
Edited by student of Dr. Lynn M Bedard, DePauw University http://www.depauw.edu
