Oceanotoga teriensis gen. nov., sp. nov., a thermophilic bacterium isolated from offshore oil-producing wells

Abstract

A novel, moderately thermophilic, chemo-organotrophic bacterium was isolated from formation fluid samples from an offshore oil-production well head at Bombay High (Western India). Cells were rod-shaped with a sheath-like outer structure ('toga'); the cells appeared singly, in pairs or in short chains. Cells grew at 25-70 6C (optimum 55-58 6C), pH 5.5-9.0 (optimum pH 7.3-7.8) and 0-12 % (w/v) NaCl (optimum 4.0-4.5 %). The isolate was able to grow on various carbohydrates or complex proteinaceous substances. The isolate reduced thiosulfate and elemental sulfur. The major end products of glucose fermentation were acetate, H 2 and CO 2 . The DNA G+C content of the genomic DNA was 26.8 mol%. Phylogenetic analysis of the 16S rRNA gene placed the strain within the order Thermotogales in the bacterial domain. On the basis of 16S rRNA gene sequence comparisons and in combination with morphological and physiological characteristics, the isolate represents a novel species of new genus, for which the name Oceanotoga teriensis gen. nov., sp. nov. is proposed. The type strain of the type species is OCT74 T (5JCM 15580Petroleum reservoirs constitute a group of unique sites with respect to their physico-chemical conditions (halophilic and thermophilic) and provide ecological niches from which taxonomically, physiologically and phylogenetically unusual microbes can be isolated (Bhupathiraju et al., 1993;Ravot et al., 1995;Fardeau et al., 1997). Members of the order Thermotogales, first described as an order containing hyperthermophilic bacteria, have been isolated from extreme environments such as deep-sea hydrothermal vents, hot springs, continental and subcontinental volcanic areas, marine sediments and oil reservoirs (Nunoura et al., 2007; Alain et al., 2002;Huber & Stetter, 1992;Davey et al., 1993).Within the order Thermotogales, the genera Thermotoga Feng et al., 2010) have been described. Representatives of these genera are anaerobic, chemo-organotrophic, thermophilic, Gram-negative, non-sporulating, rod-shaped bacteria that are characterized by a sheath-like outer structure called the 'toga ' (Huber et al., 1986). In this study, a novel strain of moderately thermophilic bacteria is described that was isolated from offshore oil-producing well heads located at Bombay High (Western India).Formation fluid samples were collected from oil-well heads into 50 ml anaerobic sterilized serum bottles containing sodium sulfide at a final concentration of 20 mM. Samples were transported to the laboratory under ambient conditions. Collection of samples was performed from December 2007 to January 2008.A basal medium composed of (l 21 deionized water): 1 g NH 4 Cl 2 , 0.3 g K 2 HPO 4 , 0.3 g KH 2 PO 4 , 0.2 g MgCl 2 . 6H 2 O, 0.1 g CaCl 2 . 2H 2 O, 10.0 g NaCl, 0.1 g KCl, 0.5 g NaC 2 H 3 O 2 , 2.0 g yeast extract, 2.0 g bio-Trypticase, 1 mg resazurin and 10.0 ml trace mineral element solution (Balch et al., 1979) was used for isolation and routine cultivation. The pH of the medium was adjusted to 7.5 with 1 M KOH at ambient temperature b...

8. Petroleum: from formation to microbiology

“…have representatives which originated only from oil reservoirs ( Fig. 8.4) thus suggesting that they might be indigenous [18,23,59]. However, the indigenous character of Thermotogales or other anaerobes more generally to the oilfield ecosystems should be considered with caution as indicated above [22].…”

“…They mainly belong to the order Thermotogales which comprises ten thermophilic to hyperthermophilic genera: Thermotoga, Thermosipho, Fervidobacterium, Geotoga, Petrotoga, Marinitoga, Thermococcoides, Kosmotoga, Oceanotoga and Defluviitoga [23,[59][60][61] ( Fig. 8.4).…”

Isolation, characterization, and survival strategies of Thermotoga sp. strain PD524, a hyperthermophile from a hot spring in Northern Thailand

“…Most members have optimal temperatures ranging from 50 to 90 °C including five described hyperthermophilic species, Thermotoga maritima MSB8 T , T. neapolitana NES T , T. petrophila RKU-1 T , T. naphthophila RKU-10 T , and Fervidobacterium changbaicum CBS-1 (Huber et al 1986;Jannasch et al 1988;Takahata et al 2001;Cai et al 2007). Currently, 12 official genera are reported, including Fervidobacterium (Patel et al 1985), Thermotoga (Huber et al 1986), Thermosipho , Geotoga (Davey et al 1993), Petrotoga (Davey et al 1993), Thermopallium (Duckworth et al 1996), Marinitoga (Wery et al 2001), Kosmotoga (DiPippo et al 2009), Oceanotoga (Jayasinghearachchi and Lal 2011), Mesotoga (Nesbø et al 2012), Defluviitoga (Ben Hania et al 2012), and Mesoaciditoga (Reysenbach et al 2013). Based on 16S rRNA phylogenetic, conserved signature indels in protein sequences and comparative genomic analyses, the members of order Thermotogales have been recently reclassified into 3 orders (Thermotogales, Kosmotogales ord.…”

Defluviitoga tunisiensis gen. nov., sp. nov., a thermophilic bacterium isolated from a mesothermic and anaerobic whey digester

“…The species belonging to the other genera in the order Thermotogales (i.e. Petrotoga, Geotoga, Kosmotoga, Thermococcoides and Oceanotoga) were all isolated from oilfield ecosystems (Davey et al, 1993;Miranda-Tello et al, 2004 DiPippo et al, 2009;Feng et al, 2010;Jayasinghearachchi & Lal, 2011). Curiously, some mesothermic ecosystems, such as anaerobic waste digesters and contaminated sediments, contain bacteria that have 16S rRNA gene sequences similar to those of thermophilic members of the order Thermotogales (van Houten et al, 2009;Briones et al, 2007; Chouari et al, 2005).…”