A study from the lab of CoE Key Researcher Alexander Loy (Centre for Microbiology and Environmental Systems Science, University of Vienna), in collaboration with other colleagues from CeMESS and China, introduces a newly discovered microbial energy metabolism, shortly termed MISO.
The rapid reaction between sulfide and solid iron minerals has long been considered a purely abiotic process, playing a critical role in the global biogeochemical cycles of sulfur and iron. The team now shows that microorganisms in oxygen-free environments, such as marine sediments and terrestrial wetlands, can harness this reaction to generate energy for growth.
Unlike the abiotic reaction, MISO bacteria couple the reduction of iron(III) oxide with the oxidation of sulfide to directly produce sulfate, effectively bypassing intermediate steps in the sulfur cycle. Thus, MISO bacteria remove toxic sulfide and may help prevent the expansion of so-called “dead zones” in aquatic environments, while fixing carbon dioxide for growth, similar to plants.
The discovery of this previously unknown biological mechanism links sulfur, iron, and carbon cycling in oxygen-free environments and underscores the metabolic ingenuity of microorganisms and their profound influence on global biogeochemical processes.
More on Alex Loy’s work
In a recent study, Alex’s teams showed that sulfoquinovose – a sulfonated glucose found in dietary green plants and algae – is a promising prebiotic compound that selectively stimulates the activities of specific gut bacteria.
In a recent article in the Austrian Newspaper profil, Alex talks about the possible link between gut microbes and chronic pain (in German).