Involvement of thermophilic archaea in the biocorrosion of oil pipelines

Abstract

Summary Two thermophilic archaea, strain PK and strain MG, were isolated from a culture enriched at 80°C from the inner surface material of a hot oil pipeline. Strain PK could ferment complex organic nitrogen sources (e.g. yeast extract, peptone, tryptone) and was able to reduce elemental sulfur (S°), Fe3+ and Mn4+. Phylogenetic analysis revealed that the organism belonged to the order Thermococcales. Incubations of this strain with elemental iron (Fe°) resulted in the abiotic formation of ferrous iron and the accumulation of volatile fatty acids during yeast extract fermentation. The other isolate, strain MG, was a H2:CO2‐utilizing methanogen, phylogenetically affiliated with the genus Methanothermobacter family. Co‐cultures of the strains grew as aggregates that produced CH4 without exogenous H2 amendment. The co‐culture produced the same suite but greater concentrations of fatty acids from yeast extract than did strain PK alone. Thus, the physiological characteristics of organisms both alone and in combination could conceivably contribute to pipeline corrosion. The Thermococcus strain PK could reduce elemental sulfur to sulfide, produce fatty acids and reduce ferric iron. The hydrogenotrophic methanogen strain MG enhanced fatty acid production by fermentative organisms but could not couple the dissolution Fe° with the consumption of water‐derived H2 like other methanogens.

Complementary Microorganisms in Highly Corrosive Biofilms from an Offshore Oil Production Facility

“…However, they may play an important role in the ecosystem (19,30). All of the archaea detected in 16S rRNA gene surveys were related to methanogenic lineages belonging to five different orders.…”

“…Likewise, there is no single corrosive biochemical reaction in biofilms, as demonstrated by metabolically versatile bacteria such as Desulfovibrio species, which can scavenge hydrogen, reduce sulfate to hydrogen sulfide, and/or reduce iron, depending on the environmental conditions (6,16). However, the composition and activity of microbial communities from corrosive biofilms appear to depend on various factors like the temperature (12,30) and the availability of carbon substrates and electron acceptors (26). Additionally, under certain conditions, microbial biofilms may have a positive role.…”

“…Direct reduction of iron might also increase corrosion by removing the Fe(III) oxide coating from metal surfaces (26,27). However, corrosion cannot be linked to a single microbial species and laboratory studies typically exhibit less severe corrosion than is reported in the field, where corrosion is associated with multispecies biofilms (28)(29)(30). Likewise, there is no single corrosive biochemical reaction in biofilms, as demonstrated by metabolically versatile bacteria such as Desulfovibrio species, which can scavenge hydrogen, reduce sulfate to hydrogen sulfide, and/or reduce iron, depending on the environmental conditions (6,16).…”

Dominance of Desulfotignum in sulfate-reducing community in high sulfate production-water of high temperature and corrosive petroleum reservoirs

“…Methanogenic archaea have been linked to elemental iron oxidation and corrosion (Uchiyama et al, 2010), as well as in the terminal degradation of hydrocarbons in petroleum reservoirs (Zengler et al, 1999), and it can also exacerbate corrosion by facilitating elemental oxidation (Davidova et al, 2012). In oil production systems, biofilm formation can cause numerous problems, including plugging of reservoirs, corrosion and biodegradation of materials and petroleum souring (Bass and Lappin-Scott, 1997).…”

Dethiosulfatarculus sandiegensis gen. nov., sp. nov., isolated from a methanogenic paraffin-degrading enrichment culture and emended description of the family Desulfarculaceae

“…Sulfate and sulfite loss were monitored by ion chromatography as previously described (Caldwell et al, 1998), while sulfur species reduction was monitored by sulfide production as previously reported (Trüper & Schlegel, 1964). Fermentation products were detected and quantified as previously described (Davidova et al, 2012).…”