Bacteriovorax stolpii
| Bacteriovorax stolpii | |
|---|---|
| Scientific classification | |
| Superkingdom: | Bacteria |
| Kingdom: | Bacteria |
| Phylum: | Proteobacteria |
| Class: | Deltaproteobacteria |
| Order: | Bdellovibrionales |
| Family: | Bacteriovoracaceae |
| Genus: | Bacteriovorax |
| Binomial name | |
| Bacteriovorax stolpii (Seidler et al.) Baer et al. | |
| Synonyms | |
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Bacteriovorax stolpii is a species of bacterium in the family Bacteriovoracaceae. It is a predator that feeds on larger Gram-negative bacteria.[1] These prey bacteria tend to live in enteric environments and have similar lipopolysaccharide structures.[2] Bacteriovorax stolpii recognizes its prey by outer membrane protein receptors, which explains why Gram-positive bacteria that lack outer membranes do not serve as prey.[2] They prey on bacteria by invading the interperiplasmic space where they feed, grow, and reproduce.[2] Bacteriovorax stolpii used to be classified in the genus Bdellovibrio because of similar morphologies and lifestyle characteristics, however they were recognized as a new genus through phylogenetic analysis.[3]
Characteristics
Bacteriovorax and Bdellovibrio genera share numerous morphological and lifestyle characteristics.[2] Bacteriovorax and similar genera are recognized by their presence of sphingolipids, which are not widely distributed in prokaryotes.[1] Bacteriovorax stolpii is known for the presence of sphinophosphonolipids in its membranes.[1] The genome size of the Bacteriovorax genus has been noted from 2.0–2.6 Mb.[2] Bacteriovorax is only predatory to Gram-negative bacteria, though they have been found in the gut of humans.[2] Bacteriovorax and Bdellovibrio are approximately 0.2-0.4 x 0.5-1.4 μm, are aerobic, with oxygen as a terminal electron acceptor, and are mesophilic.[2] They display a typical Gram-negative morphology and are motile by a single, polar, sheathed flagellum.[2]
History
The description of Bacteriovorax stolpii is based on the original description by Seidler et al.[4] Strain Uki2T is the only isolate described at this time and is the type strain of Bacteriovorax stolpii.[3] This isolate has a GC content of 41±8 mol%.[4] The optimal temperature range for growth of this organism is 15–35 °C. The major cellular fatty acids are 5:1ω8c13:0 and 13:0iso.[5] Uki2T is sensitive to most antibiotics tested (penicillin, streptomycin, neomycin, kanamycin, gentamicin, methicillin, nalidixic acid, pteridine 0/129 and vancomycin).[5]
Life cycle
Members of the Bacteriovorax exhibit the same general morphological and life cycle features as described for the genus Bdellovibrio.[2] In addition, members of this genus exhibit a biphasic life cycle, with the potential of displaying an actively predacious form as well as a PI (predatory independent), saprophytic form capable of growing on nutrient medium. Prey-dependent (wild-type) strains are comma-shaped rods, 0±5–1±4 µm in length, which demonstrate a predatory lifestyle in the presence of susceptible prey bacteria. The wild-type strains are motile by a single, polar flagellum. PI cells (mutants) are pleomorphic, demonstrating a range of cell shapes from simple rods to long, tightly spiral shaped cells.[3]
Reclassification
Most bacteria that prey on Gram-negative bacteria were lumped together in the genus Bdellovibrio.[3] This was done regardless of their isolation from various habitats and unstudied phylogenetic relatedness.[3] The previously wide genus included differences in sodium chloride tolerance and %G+C content.[2] Bacteriovorax stolpii and Bacteriovorax starrii were compared to Bdellovibrio bacteriovorus, the model bacterium for its genus, using 16S rDNA sequences and analyses.[3] There was only 81.7% 16S rDNA sequence similarity between Bdellovibrio bacteriovorus and Bacteriovorax stolpii.[2] DNA-DNA hybridization also only yielded <4% hybridization between the species.[3] On these findings, the genus Bacteriovorax was created and Bacteriovorax stolpii and Bacteriovorax starrii moved into it.[3]
References
- 1 2 3 Jayasimhulu, K.; Hunt, S.M.; Kaneshiro, E.S.; Watanabe, Y.; Giner, J-L. (2007). "Detection and Identification of Bacteriovorax stolpii UKi2 Sphingophosphonolipid Molecular Species". Journal of the American Society for Mass Spectrometry 18: 394–403. doi:10.1016/j.jasms.2006.10.014. PMID 17123828.
- 1 2 3 4 5 6 7 8 9 10 11 Bergey, D.H.; Brenner, D.J.; Krieg, N.R.; Staley, J.T. (2005). Bergey's Manual of Systematic Bacteriology. Volume 2. The Proteobacteria. Part C. The Alpha-, Beta-, Delta-, and Epsilonproteobacteria. New York, NY: Springer. pp. 1053–7.
- 1 2 3 4 5 6 7 8 Baer, Marcie L., Jacques Ravel, and Jongsik Chun (2000). "A Proposal for the Reclassification of Bdellovibrio Stolpii and Bdellovibrio Starrii into a New Genus, Bacteriovorax Gen. Nov. as Bacteriovorax Stolpii Comb. Nov. and Bacteriovorax Starrii Comb. Nov., Respectively". International Journal of Systematic and Evolutionary Microbiology 50 (1): 219–24. doi:10.1099/00207713-50-1-219. PMID 10826807.
- 1 2 Althauser, M., Samsonoff, W. A., Anderson, C. & Conti, S. F. (1972). "Isolation and preliminary characterization of bacteriophages for Bdellovibrio bacteriovorus". J Virol 10: 516–23. PMC 356493. PMID 4116140.
- 1 2 Guether, D. L., Osterhout, G. J., Dick, J. D. & Williams, H. N. (1993). Analysis of fatty acid composition of Bdellovibrio isolates. Abstract Q-243 presented at the 93rd General Meeting of the American Society for Microbiology, Atlanta, Georgia, USA.