Scientists Cultivate 'Miracle Microbe' That Can Turn Crude Oil to Methane

Scientists discovered that a microbe that dwells in an underground oil reservoir can convert crude oil to methane, and their genome analyses suggests that a special archaeon can do this all by itself.

In collaboration with a team from China, the researchers have succeeded in cultivating this microbe in the laboratory to enable them to describe exactly how the transformation goes and how these various petroleum compounds are degraded.

A 'Miracle Microbe'

While it is known that microorganisms are capable of converting oil into natural gas, it was only recently that scientists found this conversion is also possible through a previously unreported biochemical pathway.

Microorganisms typically use oil as food and energy source, while converting gas such as methane in the process. A recent discovery held that this con­ver­sion was not only pos­sible through the cooperation of different organisms, but a special archaeon can do this all by itself.

It so happens that this 'mir­acle mi­crobe' breaks down oil into meth­ane (CH4) and car­bon di­ox­ide (CO2). Researchers managed to cultivate this ar­chaeon called Meth­an­ol­i­paria from a set­tling tank of an oil pro­duc­tion fa­cil­ity.

"Meth­an­ol­i­paria is a kind of hy­brid creature that com­bines the prop­er­ties of an oil de­grader with those of a meth­ano­gen, i.e. a meth­ane pro­du­cer," ex­plains study au­thor Gunter We­gener from the Max Planck In­sti­tute for Mar­ine Mi­cro­bi­o­logy and the MARUM - Cen­ter for Mar­ine En­vir­on­mental Sci­ences at the Uni­versity of Bre­men in the study.

Upon having suc­ceeded in cul­tiv­at­ing these mi­croor­gan­isms in the labor­at­ory, the un­der­ly­ing pro­cesses it goes through exhibited unique cap­ab­il­it­ies in its genetic make-up. "In its genes it car­ries the blue­prints for en­zymes that can ac­tiv­ate and de­com­pose vari­ous hy­dro­car­bons. In ad­di­tion, it also has the com­plete gear kit of a meth­ane pro­du­cer," says We­gener.

"So far, we have only cul­tiv­ated ar­chaea that live on short-chain hy­dro­car­bons such as eth­ane or bu­tane. Meth­an­ol­i­paria, on the other hand, prefers heavy oil with its long-chain com­pounds," says co-au­thor Ra­fael Laso-Pérez, who now works at Spain's Na­tional Cen­ter for Bi­o­tech­no­logy (CNB).

New pathway of methanogenesis

In the various methods used by researchers to examine and keep a close eye on the Meth­an­ol­i­paria and its underlying processes, it was par­tic­u­larly sur­pris­ing to see was that this ar­chaeon ac­tiv­ated all the dif­fer­ent hy­dro­car­bons with one and the same en­zyme.

"Meth­ano­genic mi­crobes that use long-chain hy­dro­car­bons dir­ectly - we did­n't know these ex­is­ted un­til now. Even com­plic­ated hy­dro­car­bons with ring-like or aro­matic struc­tures are not too bulky for Meth­an­ol­i­paria, at least if they are bound to at least one longer car­bon chain. This means that be­sides our other ex­cit­ing res­ults we have also found a pre­vi­ously com­pletely un­known path­way of meth­ano­gen­esis."

Findings also showed that this microbe in particular prefers to eat rather bulky chunks of food. In addition, although Meth­an­ol­i­paria cells are cul­tured and ori­gin­ate from one of Chin­a's largest oil fields, the Shengli oil field, genetic analyses revealed that they are also dis­trib­uted all over the world.

"Our res­ults hold an en­tirely new un­der­stand­ing of oil ex­ploit­a­tion in sub­sur­face oil reser­voirs. Both the wide dis­tri­bu­tion of these or­gan­isms and the po­ten­tial in­dus­trial ap­plic­a­tions make this an ex­cit­ing field of re­search in the com­ing years," We­gener con­cludes.