Characteristics of microbiota, core sulfate-reducing taxa and corrosion rates in production water from five petroleum reservoirs in China.

Microbial diversity and activities in petroleum reservoir systems can be altered by water-flooding operation, but the current understanding of the mechanism for such changes in microbial composition characteristics and community is inadequate. In this study, microbial communities especially functional groups in production water from five petroleum reservoirs in China were investigated by chemical and molecular biological analyses. The dominant and core phyla in the five oil reservoirs were Proteobacteria, Deferribacterota, Firmicutes, Desulfobacterota, Euryarchaeota and Thermoplasmatota.

Methanogenic biodegradation of C to Cn-alkanes initiated by Smithella via fumarate addition mechanism.

In the present study, a methanogenic alkane-degrading (a mixture of C to Cn-alkanes) culture enriched from production water of a low-temperature oil reservoir was established and assessed. Significant methane production was detected in the alkane-amended enrichment cultures compared with alkane-free controls over an incubation period of 1 year. At the end of the incubation, fumarate addition metabolites (C to C alkylsuccinates) and assA genes (encoding the alpha subunit of alkylsuccinate synthase) were detected only in the alkane-amended enrichment cultures.

Methanogenic Degradation of Long -Alkanes Requires Fumarate-Dependent Activation.

Methanogenic degradation of -alkanes is prevalent in -alkane-impacted anoxic oil reservoirs and oil-polluted sites. However, little is known about the initial activation mechanism of the substrate, especially -alkanes with a chain length above C Here, a methanogenic C to C-alkane-degrading enrichment culture was established from production water of a low-temperature oil reservoir. At the end of the incubation (364 days), C to C (1-methylalkyl)succinates were detected in the -alkane-amended enrichment culture, suggesting that fumarate addition had occurred in the degradation process.