Thalassospira xianhensis sp. nov., a polycyclic aromatic hydrocarbon-degrading marine bacterium

Abstract

A polycyclic aromatic hydrocarbon-degrading marine bacterium, designated strain P-4 T , was isolated from oil-polluted saline soil in Xianhe, Shangdong Province, China. Strain P-4 T was Gram-negative-staining with curved to spiral rod-shaped cells and grew optimally with 3-6 % (w/v) NaCl and at 30 6C. The predominant fatty acids were C 18 : 1 v7c (35.0 %), C 16 : 0 (25.0 %), C 16 : 1 v7c (17.9 %), C 14 : 0 (6.2 %) and C 17 : 0 cyclo (5.2 %). The major respiratory quinone was Q-9 and the genomic DNA G+C content was 61.2±1.0 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain P-4 T belonged to the genus Thalassospira of the class Alphaproteobacteria. DNA-DNA hybridization with Thalassospira xiamenensis DSM 17429 T showed relatedness of 36.0 %, and lower values were obtained with respect to other Thalassospira species. Based on physiological and biochemical tests and 16S rRNA gene sequence analysis as well as DNA-DNA relatedness, strain P-4 T should be placed in the genus Thalassospira within a novel species. The name Thalassospira xianhensis sp. nov. is proposed, with P-4 T (5CGMCC 1.6849 T 5JCM 14850 T ) as the type strain.Polycyclic aromatic hydrocarbons (PAHs) are hydrocarbons that consist of two or more fused aromatic rings (Habe & Omori, 2003;Hedlund & Staley, 2001). PAHs are released into the marine environment as a result of various anthropogenic activities such as marine seepage and accidental discharges during the transport and disposal of petroleum products and the use of fossil fuels (Sohn et al., 2004). Some PAHs are highly carcinogenic, genotoxic and cytotoxic to marine organisms and may be transferred to humans through seafood consumption (Menzie et al., 1992). Therefore, removal of PAHs from contaminated marine environments is of considerable importance.Several PAH-degrading strains have been isolated from PAH-contaminated marine sediments (Hedlund & Staley, 2001;Kwon et al., 2005;Sohn et al., 2004). In this study, we report the characterization of a PAH-degrading marine bacterium that was isolated from saline soil contaminated with crude oil in Xianhe, Shangdong Province, China.To isolate PAH-degrading bacteria, 5 % sea-salt defined medium (5 % SSDM; Zhao et al., 2009) and 5 % SSDM with 0.5 % yeast extract (5 % SSDMY) were used. Solid 5 % SSDMY medium was prepared with 1.5 % agar. A sample of oil-polluted saline soil (1 g) was added to 100 ml 5 % SSDM medium supplemented with phenanthrene (100 mg ml 21 ) in a 300 ml Erlenmeyer flask. The culture was aerobically incubated at 30 u C in darkness on a rotary shaker operating at 200 r.p.m. After 2 weeks, 10 ml culture was transferred to 100 ml 5 % SSDM medium and incubated under the conditions described above. The enrichment was performed five or six times. Next, a culture broth dilution series was spread on 5 % SSDMY agar. After incubation for 2 days, single colonies were picked and cultivated in 5 ml 5 % SSDM using phenanthrene as the sole source of carbon and energy. These isolates developed a yellowish-orange or red...

Effect of pyrene on denitrification activity and abundance and composition of denitrifying community in an agricultural soil

“…NCW, Thalassopira xianhensis sp. nov. and Pseudomonas putida belonging to the above four groups were isolated from contaminated soils, wastewater, sludge and marine, and these species were able to degrade PAHs and other hydrocarbons (Bodour et al, 2003;Guo et al, 2008;Zhao et al, 2010;Balashova et al, 1999).…”

Magnetovibrio blakemorei gen. nov., sp. nov., a magnetotactic bacterium ( Alphaproteobacteria : Rhodospirillaceae ) isolated from a salt marsh

“…Strain MV-1 T is capable of anaerobic growth using several nitrogen species as terminal electron acceptors (N 2 O, nitrate, nitrite). The type strains of Terasakiella pusilla, Thalassospira lucentensis and Magnetospira thiophila all require oxygen as the terminal electron acceptor (Satomi et al, 2002;Ló pez-Ló pez et al, 2002;Williams et al, 2012), although other Thalassospira species are facultative anaerobes that are 'Candidatus Kopriimonas byunsanensis ' KOPRI 13522 (DQ167245) Terasakiella pusilla IFO 13613 T (AB006768) Thalassospira lucentensis DSM 14000 capable of growth on nitrate (Liu et al, 2007;Kodama et al, 2008;Zhao et al, 2010). Characterized species of Terasakiella and Thalassospira are obligate chemo-organoheterotrophs, unlike strain MV-1 T and Magnetospira thiophila, both of which are capable of chemolithoautotrophic growth using the CBB cycle (Williams et al, 2012).…”

Phylogenetic diversity of bacterial communities associated with bioremediation of crude oil in microcosms

“…The ability to degrade hydrocarbon components of crude oil has been widely detected among different bacteria, and microorganism-related bioremediation has proven to be an effective method for cleaning up residual oil in various environments (Atlas, 1995;Margesin, 2000;Röling et al, 2004;Zhao et al, 2011). Hydrocarbon-degrading bacteria from various phyla, including the Alpha-, Beta-, and Gamma-proteobacteria; Flexibacter-CytophagaBacteroides, Firmicutes, Actinobacteria, and Cyanobacteria, have been successfully cultured in the laboratory (Yakimov et al, 1998;Hennessee et al, 2009;Zhao et al, 2010;Szabó et al, 2011;Luo et al, 2012). Other studies have indicated that many microorganisms usually considered to be incapable of degrading hydrocarbon contain genes homologous to alkane-hydroxylase genes (Harayama et al, 2004).…”