Arcobacter isolated from the produced fluids of a Marcellus shale well may play a currently unappreciated role in sulfur cycling

Abstract

Microorganisms play a pivotal role in the corrosion of steel infrastructure and the biodegradation of chemical additives used for hydraulic fracturing in hydrocarbon-rich shales. Although numerous studies have reported the presence of novel microbial community members in produced waters recovered from shale gas wells within the U.S., cultivation of these microbes and characterization of their metabolisms relating to energy production has lagged. Here we report methods for isolation and cultivation of a novel bacterial species with a 16S rRNA gene sequence closely related to DNA sequences observed in produced fluids from several Marcellus and Utica-Pt. Pleasant shale wells. Phylogenetic analysis of the 16S rRNA gene revealed our isolate is closely (~99% 16S identity) related to Arcobacter marinus CS-L1, a halotolerant marine bacterium of the class Epsilonproteobacteria. The Arcobacter strain is one of several genera isolated from produced fluids collected from wells and separator tanks at the Marcellus Shale Energy and Environment Laboratory (MSEEL) field site near Morgantown, West Virginia. We are currently characterizing the salinities this Arcobacter strain can tolerate, the carbon substrates that it can utilize, and its preferred mode of respiration through cultivation studies and genome sequencing. Multiple species in previously characterized Arcobacter genus are known to be involved in sulfur oxidation (including hydrogen sulfide (H2S), elemental sulfur, and thiosulfate) using oxygen and nitrate electron acceptors. This new isolate may therefore prove important for reducing concentrations of corrosive products (e.g. H2S) under certain redox conditions in shale energy systems.

AAPG Datapages/Search and Discovery Article #90258 © 2016 AAPG Eastern Section Meeting, Lexington, Kentucky, September 25-27, 2016