Photobacterium leiognathi

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A Microbial Biorealm page on the genus Photobacterium leiognathi Photobacterium leiognathi

[[Image:Photobacterium leiognathi on agar plate.jpeg|250px|thumb|right|Photobacterium Leiognathi[Figure 1. Plate culture of Photobacterium leiognathi. Curtesy of Pearson Educacion]

Classification

Higher order taxa

Domain (Bacteria); Phylum (Proteobacteria); Class (Gammaproteobacteria); Order (Vibrionales); Family (Vibrionales); Genus (Photobacterium)

Species

NCBI: Taxonomy

Photobacterium leiognathi

[[Image:Photobacterium leiognathi.jpg‎|frame|right|150px|Photobacterium leiognathi [Figure 2. Photobacterium leiognathi cells. Curtesy of ALL-Earth.org]

Description and significance

The Actinobacteria phylum is known to include freshwater life, marine life and some common soil life. It’s important in the decomposition of organic material and carbon cycle, which puts nutrients back into the environment. Actinobacteria are also of high pharmacological interest because they can produce secondary metabolites (3). C. acidiphila is known only to be found in soil in Gerenzano, Italy. C. acidiphila forms aerial and vegetative mycelia (2). Since it’s part of the class Actinobacteria and the order Actinomycetales, it may produce novel metabolites or be an antibiotic producer. However, no information on the production of novel metabolites is currently known (1).

Genome structure

The complete genome of C. acidiphila was sequenced and published in 2009; this was the first complete genome sequenced of the Actinobacterial family Catenulisporaceae. The genome is 10,467,782 bp in length and comprises one circular chromosome. The content of the G-C in DNA is 69.8% of the total number of genes. Of the 9122 predicted genes, 99.28% were protein coding genes and just 0.76% of the genes were classified as RNA genes (2). For more information about the known functions of this genome, see tables 3 and 4 in the following article: “Complete genome sequence of Catenulispora acidiphila type strain” (2).

Cell and colony structure

Catenulispora genus consists of Gram-positive, non-motile and non-acid fast colonies of the organism that form branching hyphae. Vegetative mycelium are non-fragmentary and the aerial hyphae start to septate into chains of arthrospores (a resting sporelike cell produced by some bacteria) that are cylindrical. In C. acidiphila the spores have an average diameter of about 0.5 µm and are also known to range in length from 0.4-1 µm (1).

Metabolism

C. acidiphila is an aerobic species, but is also capable of non-pigmented and reduced growth under anaerobic and microaerophilic conditions. It has the ability to hydrolyze starch and casein. It can also use carbon sources as a source of energy. The sources of carbon that this species can use are the following: glucose, fructose, glycerol, mannitol, xylose and arabinose. C. acidiphila can’t reduce nitrates. Hydrogen sulfide (H2S) is also produced by this species (1, 2). The strain of C. acidiphila was also resistant to lysozyme, which wasn’t reported for the Catenulispora genus (2). The mechanism of how it reduces hydrogen sulfide is not known at this time.

Ecology

C. acidiphila is an acidophilic species that grows well in the pH range of 4.3-6.8, but optimally at a pH of 6.0. They can grow optimally at a temperature of between 22-28 ̊C; however, it can grow significantly between 11-37 ̊C. As of right now, C. acidiphila has only been found in Geranzano, Italy. (1).

Pathology

As of right now, C. acidiphila is not known to cause any infections or diseases. However, some species of the Actinobacteria are known to form a wide variety of secondary metabolites. Since a wide variety of secondary metabolites are a source of potent antibiotics, the Streptomyces species has been the main organism targeted by the pharmaceutical industry (3). Since C. acidiphila is part of the Actinobacteria phylum, it could possibly be targeted by the pharmaceutical industry (2).

References

[1] Nijvipakul, Sarayut, et al. 2008, "LuxG Is a Functioning Flavin Reductase for Bacterial Luminescence", American Society for Microbiology: Journal of Bacteriology, Vol 190, No 5, pg. 1531-1538,doi: 10.1128/​JB.01660-07 [2] Valentine N. Petushkov, Bruce G. Gibson,and John Lee. 1995, “Properties of recombinant fluorescent proteins from Photobacterium leiognathi and their interaction with luciferase intermediates”, Biochemistry including biophysical chemistry and molecular biology. Vol 34, No 10, pg.3300-3309, DOI: 10.1021/bi00010a020 [3] Lee,Chan Yong, Rose B. Szittner, and Edward A. Meighen. 1991, “The lux genes of the luminous bacterial symbiont, Photobacterium leiognathi, of the ponyfish; nucleotide sequence, difference in gene organization, and high expression in mutant Escherichia coli” European Journal of Biochemistry, Vol 201, Issue 1, pg. 161-167, DOI: 10.1111/j.1432-1033.1991.tb16269.x [4] Herring, Peter. 2002, “Marine microlights: the luminous marine bacteria” Microbiology Today, Vol 29, pg. 174-176 [5] Coil, David. 2011, “Microbiology Christmas Tree – luminescent bacteria,giant microbes, and more” Microbiology of the Built Environment Network [6] Boisvert, H. 1967, “Photobacterium leiognathi” National Center for Biotechnology Information [7] Yirka, Bob. 2011, “Research shows ocean bacteria glow to attract those that would eat them” Physorg.com. doi: 10.1073/pnas.1116683109

Edited by Jossary Gerry, student of Dr. Lisa R. Moore, University of Southern Maine