Glycine betaine as a substrate for methanogenesis
Methane, a greenhouse gas about 23 times more potent than carbon dioxide, is responsible for ~20% of the global warming caused by greenhouse gases. In marine and brackish environments, the two predominant methanogenesis pathways are inhibited due to competition with sulfate-reducing bacteria. However, the methylotrophic methanogenesis pathway is not inhibited by competition because it relies on different substrates like methylamines. One such compound that can be directly utilized in the methylotrophic methanogenesis pathway is the organic osmolyte glycine betaine. While many salt marsh plants use glycine betaine as an osmolyte, we do not know the concentrations of glycine betaine present in salt marsh sediment porewater or how much it contributes to methane flux in these environments. We are working to address these questions.