Methanogenic bacteria, methanogenesis and methane emission from rice paddies

Abstract

Methane is an important greenhouse gas and controls several chemical processes and species in the troposphere and stratosphere. A group of anaerobic bacteria, the methanogens, which occur in a wide variety of habitats, produce CH₄ as a product of their catabolism. Methanogenesis is a complex process and is affected by several abiotic and biotic factors. The presence of methanogens, other cooperating micro-organisms, anaerobic conditions, and rice plants as conduit for transferring CH ₄ formed in the anaerobic environment to the atmosphere, make rice paddies an important source of CH₄ for the atmosphere. However, the current estimates of global emission of CH₄ from rice paddies need to be substantially reduced. There is an indication that global methane emission is only in the range of 7.34-27.81 Tg yr⁻¹.