Desulfovibrio alaskensis sp. nov., a sulphate-reducing bacterium from a soured oil reservoir

Abstract

A novel sulphate-reducing bacterium (Al1 T ) was recovered from a soured oil well in Purdu Bay, Alaska. Light and atomic force microscopy observations revealed that cells were Gram-negative, vibrio-shaped and motile by means of a single polar flagellum. The carbon and energy sources used by the isolate and the salinity, temperature and pH ranges facilitating its growth proved to be typical of a partial lactate-oxidizing, moderately halophilic, mesophilic, sulphate-reducing bacterium. Analysis of the fatty acid profile revealed that C 18 : 0 , isoC 15 : 0 and isoC 17 : 1 v7c were the predominant species. Fatty acid profile and complete 16S rRNA gene sequencing demonstrated the similarity between strain Al1 T and members of the genus Desulfovibrio. The position of strain Al1 T within the phylogenetic tree indicated that it clustered closely with Desulfovibrio vietnamensis DSM 10520 T (98?9 % sequence similarity), a strain recovered from a similar habitat. However, whole-cell protein profiles, Fourier-transform infrared studies and DNA-DNA hybridization demonstrated that, in spite of the high level of 16S rRNA gene sequence similarity, there is sufficient dissimilarity at the DNA sequence level between D. vietnamensis DSM 10520 T and strain Al1 T (10?2 % similarity) to propose that strain Al1 T belongs to a separate species within the genus Desulfovibrio. Based on the results obtained, the name Desulfovibrio alaskensis sp. nov. is therefore proposed, with Al1 T (=NCIMB 13491 T =DSM 16109 T ) as the type strain.

Vi Khuẩn Khử Sunphat Ưa Ấm Sử Dụng Dầu Thô Desulfovibrio Desulfuricans Đh3p Phân Lập Từ Giếng Khoan Dầu Khí Mỏ Đại Hùng, Vũng Tàu

“…KSF ưa ấm có pH thích hợp nằm khoảng 6.8 -7.5 . Tuy vậy chúng vẫn có thể sống ñược nếu pH giảm xuống ñến 5 hay tăng lên ñến 10 (Dang et al, 1996;Lien, Beeder, 1997;Feio et al, 2004). Vậy chủng ðH3P có khoảng pH tối ưu cho sinh trưởng giống như các KSF ưa ấm khác không?…”

“…Kết quả (hình 3D) cho thấy chủng ðH3P có khả năng sinh trưởng trong dải pH từ 5 ñến 8 và pH trung tính hơi kiềm (pH 7-8) là pH tối ưu cho sinh trưởng của chủng này. Kết quả này một lần nữa khẳng ñịnh lại dải pH phù hợp cho sinh trưởng của KSF ưa ấm nói chung (Lien, Beeder, 1997;Feio et al, 2004;CravoLaureau et al, 2004; cũng như KSF ưa ấm phân lập từ giếng khoan dầu khí Vũng Tàu (Dang và cs, 1996; Lại Thúy Hiền, ðặng Phương Nga, 1998).…”

Mo and W bis-MGD enzymes: nitrate reductases and formate dehydrogenases

“…More recently, the characterization of the enzyme D. alaskensis Fdh, which can incorporate Mo and W at the active site, was reported [23]. R. capsulatus W-DMSO reductase and E. coli W-TMAO reductase were obtained in a medium supplemented with tungsten, but D. alaskensis W-Fdh and Mo-Fdh were co-purified in a medium with traces of W and Mo, which was shown to better mimic the growth conditions experienced by SRB in their natural habitats [52].…”

Corrosion of Iron by Sulfate-Reducing Bacteria: New Views of an Old Problem

“…Two of the isolates, Desulfovibrio ferrophilus and Desulfopila corrodens, have been key in the recent investigations of this new type of microbe-metal interaction (12,39,60,86). Such strains have probably evaded earlier discovery as they are rapidly outcompeted by "conventional" organotrophic SRB in the commonly used media that employ high concentrations of organic substrates such as lactate (91,92). It should be emphasized in this context that many of the commonly studied organotrophic SRB do not show the capability to corrode iron directly via the EMIC mechanism (12,39,47).…”