They therefore suspect the main source of food for AAPB is dissolved organic matter released by phytoplankton.

ECONOMIST: Bacteria and climate change: Invisible carbon pumps | The

If AAPB could be recruited, they would provide an alternative way of getting the sea to lock up CO2.

ECONOMIST: Bacteria and climate change: Invisible carbon pumps | The

It is possible that AAPB release such compounds during their normal metabolism.

ECONOMIST: Bacteria and climate change: Invisible carbon pumps | The

Indeed, he has found that AAPB are particularly prone to such infections and his team have isolated a virus that seems to be specific to this type of bacterium.

ECONOMIST: Bacteria and climate change: Invisible carbon pumps | The

That started happening in 2006, when Dr Jiao developed a technique called time-series observation-based infra-red epifluorescence microscopy, or TIREM for short, that is able to measure the amount of AAPB in the oceans accurately.

ECONOMIST: Bacteria and climate change

It was discovered ten years ago that AAPB produce refractory molecules when they metabolise sugars and L-amino acids, but it is only recently that the scale on which they do so has become apparent.

ECONOMIST: Bacteria and climate change

After sampling waters from the Pacific, Atlantic and Indian oceans at all latitudes, they found that the amount of AAPB in the water is controlled mainly by the level of planktonic algae in the region, rather than by the amount of light.

ECONOMIST: Bacteria and climate change: Invisible carbon pumps | The

Based on these findings, Dr Jiao and his colleagues propose that AAPB, and possibly other, similar microbes, have a predominant role in pumping carbon into a pool of compounds that cannot be turned back into carbon dioxide by living creatures, thereby building up a large reservoir that keeps carbon out of the atmosphere.

ECONOMIST: Bacteria and climate change