A mechanistic approach is presented to describe oxidation of the greenhouse gas methane in the rice rhizosphere of flooded paddies by obligate methanotrophic bacteria. In flooded rice paddies these methanotrophs compete for available O(2) with other types of bacteria. Soil incubation studies and most-probable-number (MPN) counts of oxygen consumers show that microbial oxygen consumption rates w...

In sediments, methane-oxidizing bacteria live in opposing gradients of methane and oxygen. In such a gradient system, the fluxes of methane and oxygen are controlled by diffusion and consumption rates, and the rate-limiting substrate is maintained at a minimum concentration at the layer of consumption. Opposing gradients of methane and oxygen were mimicked in a specific cultivation set-up in wh...

Symbioses between marine invertebrates and their chemoautotrophic and methanotrophic symbionts are now known to exist in a variety of habitats where reduced chemical species are present. The utilization of chemical energy and reliance on C(1) compounds by these symbioses are well documented. Much less is known about their metabolism of nitrogen. Earlier work has shown that the tissues of organi...

The methane-emitting cold seeps of Hikurangi margin (New Zealand) are among the few deep-sea chemosynthetic ecosystems of the Southern Hemisphere known to date. Here we compared the biogeochemistry and microbial communities of a variety of Hikurangi cold seep ecosystems. These included highly reduced seep habitats dominated by bacterial mats, partially oxidized habitats populated by heterotroph...

Methanotroph abundance was analyzed in control and long-term nitrogen-amended pine and hardwood soils using rRNA-targeted quantitative hybridization. Family-specific 16S rRNA and pmoA/amoA genes were analyzed via PCR-directed assays to elucidate methanotrophic bacteria inhabiting soils undergoing atmospheric methane consumption. Quantitative hybridizations suggested methanotrophs related to the...