Methane is usually produced from petroleum by consortia of petrolem-degrading bacteria and methanobacteria. A team from Shenzhen University, the Chengdu Biogas Institute and the Max-Planck Institute of Marine Microbiology in Bremen has now isolated an archaebacterium from a oil reservoir surface which grows on petroleum in the absence of other petroleum degraders. Molecular analyses revealed that Candidatus Methanoliparum contains and overexpresses genes encoding alkyl-coenzyme M reductases and methyl-coenzyme M reductases, the marker genes for archaeal multicarbon alkane and methane metabolism. Incubation experiments with different substrates and mass spectrometric detection of coenzyme-M-bound intermediates confirm that Ca. Methanoliparum thrives not only on a variety of long-chain alkanes, but also on n-alkylcyclohexanes and n-alkylbenzenes with long n-alkyl (C≥13) moieties.
In traditional recovery process, crude oil deep underground is recovered by the pressure of water or chemicals, but more than half of the deposits are difficult to recover and stay underground.
The wide distribution of Ca. Methanoliparum could lead to a new process where the crude oil could be degraded into methane leading to a mixed recovery of oil and methane with higher recovery efficiency. The exploitation life of depleted oil fields could thus be extended.