Injecting bacteria into rice paddies could reduce methane by over 90%

A newly discovered bacteria shown to reduce greenhouse gas produced by rice fields by up to 93%

Researchers in Denmark and Germany have shown that adding a recently discovered bacteria, called a “cable bacteria,” to rice plantings in their test lab resulted in a 93% reduction in the release of methane gas. Today rice fields worldwide are responsible for over 11% of all methane, a greenhouse gas several times more potent than CO2. The cable bacteria, one centimeter long (which is big for a bacteria), is named for its ability to create an electrical current along its filaments which oxidates the sulfides that cause methane, creating sulfates in deeper soils. This causes a downward migration of sulfates, boosting sulfate density in soils that outcompetes methanogens, the bacteria that cause methane gas.  Aboveground plant growth was not affected by adding cable bacteria in this experiment.

The current practice of adding sulfates (ammonium sulfate or gypsum) to reduce methane causes an unhealthy build-up of sulfates in topsoil. But with bacteria recycling sulfides into sulfates below the surface, this build-up is prevented. The production of methane gas was reduced by 93% in this study. Field trials will follow to test the results on a larger scale.