Microbial Physiology and Stress Adaptation of Anaerobic Methanotrophs

Abstract

Coastal ecosystems are dynamic hotspots for methane. They are highly sensitive to anthropogenic impacts and climate-change derived challenges. This PhD dissertation investigated the mechanisms by which anaerobic methanotrophs, important microorganisms in counteracting methane emissions, respond to coastal ecosystem stressors such as sulfide, nitric oxide, and salinity-induced osmotic pressure. Additionally, sulfide was studied in the context of sulfate-dependent anaerobic oxidation of methane (S-AOM) in meromictic Lake Cadagno. To conduct this investigation, we used a complementary approach, combining co-cultures of anaerobic methanotrophs in bioreactors, enrichments started with anoxic coastal sediments, along with biogeochemical measurements, meta-omics analysis, stable isotope activity tests, molecular assays, and physiological studies.