The agricultural production of ruminants is responsible for 24% of global methane
emissions, contributing 39% of emissions of this greenhouse gas from the agricultural …

Seaweeds are macroalgae, which can be of many different morphologies, sizes, colors, and
chemical profiles. They include brown, red, and green seaweeds. Brown seaweeds have …

The diagenetic cycling of carbon within recent unconsolidated sediments and soils generally
can be followed more effectively by discerning changes in the dissolved constituents of the …

Production and consumption processes in soils contribute to the global cycles of many trace
gases (CH4, CO, OCS, H2, N2O, and NO) that are relevant for atmospheric chemistry and …

Methylmercury is a potent human neurotoxin, to which the fetus is particularly sensitive (I).
Concentrations in fish from freshwater lakes are often elevatedabove guidelines for human …

Methane is the most abundant organic chemical in Earth's atmosphere, and its concentration
is increasing with time, as a variety of independent measurements have shown …

Microbial arsenic (As) methylation and demethylation are important components of the As
biogeochemical cycle. Arsenic methylation is enhanced under flooded conditions in paddy …

Publisher Summary This chapter highlights the physiology of autotrophic ammonia-and
nitrite-oxidizing bacteria. Several aspects of the physiology of nitrifiers of relevance to their …

Life evolved and flourished in the absence of molecular oxygen (02). As the 02 content of
the atmosphere rose to the present level of 21% beginning about two billion years ago …

Field and laboratory studies of anoxic sediments from Cape Lookout Bight, North Carolina,
suggest that anaerobic methane oxidation is mediated by a consortium of methanogenic …