Alexander Loy
Iron Oxide (III) concretions found on a beach
A team of Vienna University researchers found that the metabolism of a rock-breathing microorganism allows to oxidize toxic sulfretos and reduce iron minerals to obtain energy.
According to a new study, the so -called “Bacteria MISO”They turn the dangerous sulfate sulfide into sulfates, thus helping to wrap the expansion of oxygen -free zones in the planet’s oceans and wet zones.
Led by an international team of scientists, led by microbiologists at the University of Vienna, and published on Wednesday in the journal Nature, suggests that these organisms may be responsible for even 7% of global removal of sulfuretes existing in marine sediments.
Researchers found that the reaction between toxic hydrogen sulfide and solid iron minerals It’s not just a chemical processbut also a biological process so far unknownin which versatile microorganisms in marine sediments and terrestrial moist zones remove toxic sulfide and use it to grow.
These bacteria may prevent the expansion of the so -called “dead zones” Without oxygen in aquatic environments, the study authors say.
Os Carbon Biogeochemical Cyclesnitrogen, sulfur and iron describe how These elements become through reduction and oxidation reactions (Redox reactions) and how they circulate between the atmosphere, water, soil, rocks and living organisms.
These cycles are closely linked to the climate of the earthsince they regulate the flow of greenhouse gases and influence the planet’s thermal balance.
Os microorganisms are in the center of virtually every step of these round transformations, using compounds such as sulfur and iron for breathing, form similar to the way human beings They use oxygen to metabolize food.
O sulfur and iron are particularly vital For microbial life in oxygen -free environments, such as the oceanic background or moist zones.
Sulfur exists In various forms – such as gas in the atmosphereas a sulfate in the oceans or integrated in rock minerals. Similarly, iron can transit between different forms depending on the presence of oxygen.
When microorganisms metabolize sulfursimultaneously change the shape of the iron-and vice versa, explains the.
This coupling of sulfur and iron cycles has deep implications, influencing the nutrient availability and the production or decomposition of greenhouse gases such as carbon dioxide and methane.
Understanding these interconnected cycles is fundamental to predict how ecosystems react to pollutionclimate change and other human activities.
Breathe iron minerals to detoxify sulfide
The activity of microorganisms specialized in oxygen -free environments, such as marine sediments, moist zones and freshwater aquifers, produces hydrogen sulfide – a toxic gas with a characteristic smell to rotten eggs.
The interaction between sulfide and solid minerals of iron oxide (III), such as rusty iron, plays an essential role in controlling sulfide concentrations.
So far, biogeochemical models have treated this reaction as purely abioticresulting mainly in the formation of elementary sulfur and Iron Monosulfurete (FES)a black mineral responsible, for example, for the dark color of the beach sediments in low oxygen conditions.
“We show that this Redox reaction, so important to the environment, is not exclusively chemical,” explains Alexander Loyresearcher at the University of Vienna and main author of the study. “Microorganisms also get it enjoy your growth”.
The now discovered microbial energy metabolism, designated MISOassociates the reduction of iron oxide (III) with sulfide oxidation. Unlike the chemical reaction, MISO produces directly sulfatebypassing intermediate steps of the sulfur cycle.
“Miso bacteria remove toxic sulfide and can help prevent the expansion of so-called ‘dead zones’ in aquatic environments, while setting carbon dioxide to grow-similar to plants,” adds Marc Mussmann, also a researcher at the University of Vienna and co-author of the study.
“This discovery demonstrates the metabolic ingenuity of microorganisms and underlines their indispensable role in the modeling of the global cycles of the elements on Earth, ”concludes Loy.
