Methanotrophic bacteria can reducing greenhouse gas emissions and promote plant growth at the same time

A group from Institute for Water Research and Department of Microbiology, University of Granada, 18071 Granada, Spain, etc. has reported that methanotrophic bacteria can reducing greenhouse gas emissions and promote plant growth at the same time.

Although carbon dioxide (CO2) receives the most attention as a global warming factor, there are other gases to consider, for instance methane (CH4). It is thought that methane is the cause of at least one-fourth of the current gross warming. Atmospheric concentrations of methane are rising rapidly, principally due to anthropogenic contributions, with wastewater treatment facilities, landfills, and livestock considered to be the key producers. The removal of atmospheric methane is needed to offset the steady release of methane, thereby limiting the contribution of this potent greenhouse gas to climate change.

This paper explores the potential of methanotrophic bacteria as plant-growth-promoting rhizobacteria (PGPR) to save plants from droughts and also to reduce greenhouse gas, methain, at the same time. Since methane oxidation leads to water production as a byproduct (i.e., CH4 + O2 = [CH2O] + H2O), it was thought that methane-consuming microbes produce water intracellularly and are capable of surviving with a limited external water supply, releasing excess water into its environment.
Actually, the highest values of relative humidity in vermiculite used as a soil were detected in some methanotrophic innoculated samples, with values of 72.29 ~ 62.26%. It is noteworthy that in the absence of methane, its relative humidity was drastically reduced by almost half. These results suggest that the methanotrophic bacteria could efficiently preserve water using methane-derived metabolic water. And interestingly, the PGPR effect was maximized with the same methanotrophic bacteria, which can help water preservation, at the same time.