Cycloclasticus pugetii gen. nov., sp. nov., an Aromatic Hydrocarbon-Degrading Bacterium from Marine Sediments

Abstract

Three heterotrophic bacterial strains were isolated from different locations in Puget Sound, Washington, by using biphenyl as the principal carbon source. These strains grow by using a limited number of organic compounds, including the aromatic hydrocarbons naphthalene, phenanthrene, anthracene, and toluene, as sole carbon sources. These aerobic, gram-negative rods are motile by means of single polar flagella. Their 16s rRNA sequences indicate that they are all members of the y subdivision of the Proteobacteriu. Their closest known relatives are the genera Methylobacter and Methylomonas (genera of methane-oxidizing bacteria), uncultured sulfur-oxidizing symbionts found in marine invertebrates, and clone FL5 containing 16s ribosomal DNA amplified from an environmental source. However, the Puget Sound bacteria do not use methane or methanol as a carbon source and do not oxidize reduced sulfur compounds. Furthermore, a 16s rRNA base similarity comparison revealed that these bacteria are sufficiently different from other bacteria to justify establishment of a new genus. On the basis of the information summarized above, we describe a new genus and species, Cycloclasticus pugetii, for these bacteria; strain PS-1 is the type strain of C. pugetii.Nearshore marine environments receive a wide variety of recalcitrant organic compounds, including hydrocarbons from shipping activities, terrestrial and freshwater runoff and pollution, sewage, and accidental spillage of fuels and other petroleum products. The aliphatic fraction of petroleum hydrocarbons tends to be more easily degraded than the aromatic compounds. Polycyclic aromatic hydrocarbons (PAHs) are of particular concern because of their persistence and toxicity. Many of these compounds are known to be mutagenic and are suspected carcinogens. Because of their relatively poor solubility in water and hydrophobic nature, PAHs strongly adsorb to particulate material, settle to the seafloor, and accumulate in marine sediments. High concentrations of toxic contaminants in sediments have been correlated with a high incidence of histopathological abnormalities in bottomfish, toxicity to sediment infauna, and other adverse effects (41, 42). In Puget Sound and in many other areas of the world, another source of PAH pollution has been the wood products industry; many sites are contaminated with creosote, a wood preservative that is primarily composed of PAHs (33).Despite their refractory nature, hydrocarbons are degraded by microbial activity in marine environments. Alkane degradation has been studied most thoroughly, and degradation of PAHs has also been described (28). Although most of the research on the microbiology of PAH degradation has focused on a few Pseudomonas species, other bacterial genera whose members have been reported to degrade PAHs include the genera Aeromonas, Flavobacterium, Beijerinckia, Alcaligenes, Micrococcus, Vibrio, Flavobacterium, and Mycobacterium (13, 18, 20, 21, 24, 25, 32, 34, 43).In this paper we describe the isolation and characterization of ...

Obligate oil-degrading marine bacteria

“…dieselolei [10], C. pugetii [11], and C. oligotrophus [12], and more nutritionally versatile species with less restricted substrate profiles, like A. venustensis and C. spirillensus [9,13]. The three other genera of the OHCB group, despite being represented by numerous members, are monophyletic and represented by the three type species Oleiphilus messinensis [14], Oleispira antarctica [15] and Thalassolituus oleivorans [16].…”

Marine Oil-Degrading Microorganisms and Biodegradation Process of Petroleum Hydrocarbon in Marine Environments: A Review

“…Shi et al have found that 91.1 % of nalkane was degraded in 7 days, while the degradation rate of Naphthalene, 1-methylnaphthalene, 2-methylnaphtha-lene, 2,6-dimethylnaphthalene, and phenanthrene Vibrio cyclotrophicus sp.nov. [35] Naphthalene, anthracene, phenanthrene, and pyrene Aeram onas punctata TII [14,53] Phenanthrene and Chrysene Vibrio, Pseudoalteromonas, Marinomonas [31] n-Alkanes aromatic hydrocarbon, naphthalene, phenanthrene and anthracene Cycloclasticus oligotrophus [23,73] n-Alkanes, branched alkanes and alkylbenzenes Alcanivorax sp. [22,29,30,48,75] Aliphatic hydrocarbons, alkanoles, and alkanoates Oleiphilusand, Oleispira [28,74] Alkanes…”

Vibrio cyclotrophicus sp. nov., a polycyclic aromatic hydrocarbon (PAH)-degrading marine bacterium.

“…The pHs and salinities that allowed growth were examined in ONR7a broth with 0n1 % Bacto peptone (Difco). For pH determinations, media were prepared with alternative buffers at 25 mM concentrations near their pK a values, as described (Dyksterhouse et al, 1995). Salinities were adjusted by varying the inorganic salt concentrations [except NH % Cl, Na # HPO % , FeCl # and TAPSO (3[N-tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonic acid ; Sigma).…”