An international research team led by microbiologists Marc Mussmann and Alexander Loy at the University of Vienna has uncovered a completely new type of microbial metabolism. The newly identified microorganisms, known as MISO bacteria, are able to „breathe” iron minerals by oxidizing toxic sulfide. The scientists discovered that the reaction between hydrogen sulfide – a poisonous gas – and solid iron minerals is not only a chemical process, but also a biological one. In this newly revealed pathway, adaptable microbes living in marine sediments and wetland soils remove toxic sulfide and use it as an energy source for growth. These bacteria may also play an important role in preventing the expansion of oxygen-depleted „dead zones” in aquatic ecosystems.

The findings were recently published in Nature.

How Microbes Power Earth’s Element Cycles

The movement of key elements such as carbon, nitrogen, sulfur, and iron through the environment occurs through what are known as biogeochemical cycles. These transformations take place through reduction and oxidation (redox) reactions that move elements between air, water, soil, rocks, and living things. Because these cycles regulate greenhouse gases, they have a direct influence on Earth’s climate and temperature balance. Microorganisms drive nearly every step of these processes, using substances like sulfur and iron for respiration in much the same way humans rely on oxygen to metabolize food.

Citește mai mult