Vibrio splendidus

Classification

NCBI Taxonomy

Vibrio splendidus

Lineage:Bacteria; Proteobacteria; Gammaproteobacteria; Vibrionales; Vibrionaceae; Vibrio; Vibrio splendidus; Vibrio splendidus.

Genome Structure

The genome of Vibrio splendidus consists of two circular chromosomes. The larger of the two, chromosome 1, is 3299 kb, and it contains 199 out of 205 of the minimal gene set. Chromosome 2 is 1675 kb long and is subject to more frequent genome rearrangements than chromosome 1, in which there is a higher conservation of gene order. Although differing in size, chromosomes 1 and 2 have similar G+C contents (44.03% G+C and 43.64% G+C, respectively) (Le Roux 2009).

The genome of V. splendidus also contains 4498 predicted open reading frames, with 2998 on chromosome 1 and 1500 on chromosome 2. Chromosome 1 contains 7 rRNA genes and 97 tRNA genes, while chromosome 2 contains 1 rRNA and 17 tRNA genes (Le Roux 2009).

Few mobile elements exist in the genome of V. splendidus. Chromosome 1 houses one RS1-like phage and 8 transposons, and chromosome 2 contains one transposon as well. Because all DNA repair enzymes are present in the organism, the high genotypic diversity between strains of V. splendidus is most likely not to be the result of a missing repair pathway. Rather, because it contains several genes that play a role in transformation competence (including those coding for a type IV pilus assembly complex and a putative DNA binding protein), it has been suggested that natural transformation may be one of the sources of high genomic polymorphism (Le Roux 2009).

One surprising finding regarding the organism's genome is the nature of its chromosomal integron; in some strains of Vibrio splendidus, it is very small, while in others, it is completely absent from the genome. Prior to this finding, the chromosomal integron was thought to be a universal feature of all species in the Vibrio genus (Le Roux 2009).

Cell Structure, Metabolism and Life Cycle

Vibrio splendidus is a gram negative bacterium. It is rod-shaped, and has perichous sheathed polar flagella. It is also luminous, and for optimal growth it requires a salt concentration between 300 and 400 mM Na+ (Baumann 1980).

V. splendidus is chemoorganotrophic in nature, obtaining its energy from chemicals and electrons from organic sources, and its metabolism is facultatively fermentative (Thompson 2005).

Ecology and Pathogenesis

Habitat

Vibrio Splendidus is a dominant culturable Vibrio found in costal maring sedements, seawater and bivalve organisms (Le Roux).

symbiosis; biogeochemical significance; contributions to environment.

If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

Ecology

Vibrio splendidus a planktonic vibrio species found in oceanic environment. It is a facultative anaerobe that has strains that have been found to be culturable in a lab environment. It has been found to be extremely prevalent in the gulf coast where it is able to be sampled out of most open water in the gulf. V. splendidus strains have been found that emit a sort of bioluminescence that is visible in high cell concentration areas. A study has found that V. splendidus and Vibrio harveyi are so closely related that a site specific probe for V. harveyi was also found to hybridize with V. splendidus, although the true phylogenetic relationship between these two organisms is still unknown.

{It has been found to kill some vertebrates.}

Vibrio Spendidus is a bioluminating organism. This means that the light it emits is not actual emitting a lot of thermal radiation. It is commonly accepted that nearly 90% of marine animals emit some sort of bioluminescence, so just that fact could show how common this organism may be in aquatic environments. This light that is emitted by the organism can offer many benefits to any animal that chooses to uptake this microbe and associate it with itself. It is speculated that the light could be used as an attractant luring prey in, as a deterrent keeping predators away or even simply a light source that allows the animal to see things that reflect the certain wavelength of light that V. splendiduus is emitting. It is still not very well known what else this organism may be doing in marine life.

{Emits bioluminescence}

Pathology

The Vibrio splendidus metallo protease gene vsm is hypothesized to directly contribute to this organisms toxic effect on oysters . Other research is attempting to determine the toxic effects of this gene product on bivalves and to further determine its pathogenic ability (Le Roux 2006). {Vibriosis}

{Kills some invertebrates}

Significance

The creation of biofuels and renewable energy resources by microbial fermentation is becoming a prominent area of research. The product yield and efficiency of processes is important for the development of such biofuels. The common biofuel substrates, corn and sugar present issues with efficient production and competition with the food market supply. Current microbial technology is unable to address the cost and complex metabolic requirements to make use of the sugars released from recalcitrant polysaccharides (Stephanopolos). Biomass products such as seaweed could potentially be used as such a substrate if a sustainable method was developed for the release and metabolism of such sugars from the substrate (Adam 2012). Brown macroalgae has the potential to be used for the creation of biofuels (Somerville 2010). Brown macroalgae does not compete with food crops for the use of landmass, fertilizer or fresh water and this has no major influence on the production of food crops (Roesijadi). This macroalgae does not contain lignin and its sugars can be released by crushing or milling (Adam 2012). It is estimated that 59 dry metric tons/ha of this substrate can be produced per year with an optimal yield of 0.254 ethanol/weight of dry algae (Adam 2012). The estimated bio-ethanol activity from this crop is 19,000 liters/ha/year (Adam 2012). This ethanol yield is 2x greater than that of sugar and 5x than that of corn (Adam 2012). The most abundant sugars in brown macroalgae is alginate, mannitol and glucan (Adam 2012). The full potential for the use of alginate has not been realized because of lack of processes to Current technologies have not developed a method for the microbial metabolism of alginate and thus, the full potential of this substrate has not been realized. Vibrio splendidus contains a 30 kilo-base pair fragment which may codes for the transport and metabolism of alginate (Adam 2012). Direct cloning of the fragment and reconstruction of the pathway was done creating a fosmid library using fragments of the Vibrio splendidus genomic DNA coding for the alginate metabolism pathway (pGAL) and transforming it into E. coli. It was reported that this engeneered organism could produce ethanol at levels over 80% of the estimated maximum yield (Adam 2012).

References

1.Somerville C, Youngs H, Taylor C, Davis SC, Long SP. “Feedstocks for lignocellulosic biofuels”.“Science”. 2010 329(5993):790-2. 2. Gay M, Berthe FC, Le Roux F. “Screening of Vibrio isolates to develop an experimental infection model in the Pacific oyster Crassostrea gigas.” “Diseases of Aquatic Organisms”. 2004 Apr 21;59(1):49-56. 3. Le Roux F, Binesse J, Saulnier D, Mazel D. “Construction of a Vibrio splendidus mutant lacking the metalloprotease gene vsm by use of a novel counterselectable suicide vector.””Applied Environmental Microbiology”.2007 Feb;73(3):777-84. 4. Wargacki AJ, Leonard E, Win MN, Regitsky DD, Santos CN, Kim PB, Cooper SR, Raisner RM, Herman A, Sivitz AB, Lakshmanaswamy A, Kashiyama Y, Baker D, Yoshikuni Y. “An engineered microbial platform for direct biofuel production from brown macroalgae.”“Science”. 2012 Jan 20;335(6066):308-13. 5.Stephanopoulos G. “Challenges in engineering microbes for biofuels production.”“Science”. 2007 Feb 9;315(5813):801-4. 6.Shin Y, Liu J, Wang LQ, Nie Z, Samuels WD, Fryxell GE, Exarhos GJ. “Ordered Hierarchical Porous Materials: Towards Tunable Size- and Shape-Selective Microcavities in Nanoporous Channels The Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy under Contract DE-AC06-76RL0 1830. This work is supported by the Office of Basic Energy Sciences, Division of Materials Sciences, of the U.S. Department of Energy.” “Angewandte Chemie International Edition”. 2000 Aug 4;39(15):2702-2707. 7.[1]Le Roux F, Zouine M, Chakroun N, Binesse J, Saulnier D, Bouchier C, Zidane N, Ma L, Rusniok C, Lajus A, Buchrieser C, Médigue C, Polz MF, Mazel D. "Genome sequence of Vibrio splendidus: sn abundant planctonic marine species with a large genotypic diversity." Environmental Microbiology. 2009 Aug;11(8):1959-70. 8.[2] Thompson FL, Gevers D, Thompson CC, Dawyndt P, Naser S, Hoste B, Munn CB, Swings J. "Phylogeny and Molecular Identification of Vibrios on the Basis of Multilocus Sequence Analysis." Applied Environmental Microbiology. 2005 Sep;71(9):5107-15. 9.[3] Baumann P, Baumann L, Bang S, Woolkalis M. "Reevaluation of the Taxonomy of Vibrio, Beneckea, and Photobacterium: Abolition of the Genus Beneckea." Current Microbiology. 1980;4:127-132.

Author

Page authored by _____, student of Prof. Jay Lennon at Michigan State University.

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