Скачать или смотреть Microbial iron cycling in biogeochemical cycles past and present: Casey Bryce

Microbial iron cycling in biogeochemical cycles past and present
Casey Bryce, University of Bristol, UK
The redox transition between the two environmentally relevant valence states of iron (Fe2+ and Fe3+) has a fundamental role in natural systems. Iron is a readily available electron source and sink for microbial processes in aquatic and terrestrial habitats, and both abiotic and microbially-mediated Fe redox transformations exert control on the mobility of contaminants and nutrients. In this talk I will discuss the microbial processes which tie iron redox transformations to other major biogeochemical cycles, with a particular focus on photoferrotrophs. These photosynthetic bacteria, which utilise Fe(II) as an electron donor for CO2 fixation, were probably a key driver of Fe(III) mineral formation in the Earth’s early oceans and contributed to the deposition of vast iron formations. I will discuss their unique physiology and the metabolic factors which have shaped their ecology and distribution in modern and ancient habitats.