Gas seepage pockmark microbiomes suggest the presence of sedimentary coal seams in the Oxarfjordur graben of NE-Iceland

• Main Authors: Þorsteinsdóttir, Guðný Vala, Blischke, Anett, Sigurbjörnsdóttir, Auður, Óskarsson, Finnbogi, Arnarson, Þórarinn Sveinn, Magnússon, Kristinn Pétur, Vilhelmsson, Oddur
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2019
• Subjects: Öxarfjörður; Iceland
• Online Access: http://hdl.handle.net/1807/97611; http://www.nrcresearchpress.com/doi/abs/10.1139/cjm-2019-0081

Natural gas seepage pockmarks are found off- and onshore in the Öxarfjörður graben, Iceland. The bacterial communities of two onshore seepage sites were analysed by 16S rRNA gene amplicon sequencing; the geochemical characteristics, hydrocarbon content, and the carbon isotope composition of the sites were also determined. While one site was found to be characterised by biogenic origin of methane gas, with a carbon isotope ratio (δ13C (‰)) of −63.2, high contents of organic matter and complex hydrocarbons, the other site showed a mixed origin of the methane gas (δ13C (‰) = −26.6) with geothermal characteristics and lower organic matter content. While both sites harboured Proteobacteria as the most abundant bacterial phyla, the Deltaproteobacteria were more abundant at the geothermal site and the Alphaproteobacteria at the biogenic site. The Dehalococcoidia class of phylum Chloroflexi was abundant at the geothermal site while the Anaerolineae class was more abundant at the biogenic site. Bacterial strains from the seepage pockmarks were isolated on a variety of selective media targeting bacteria with bioremediation potential. A total of 106 strains were isolated and characterised, including representatives from the phyla Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. This article describes the first microbial study on gas seepage pockmarks in Iceland. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.