Red Sea brine pools hint at life before oxygen

Researchers found manganese-oxidizing microbes such as Nitrospira in an oxygen-free brine pool 1,770 m deep in the Red Sea, with sediments enriched in manganese, iron, molybdenum and copper over 100 times above background levels. The signatures suggest metal oxidation may have powered early life before the Great Oxidation Event 2.4–2.2 billion years ago.

• Nitrospira microbes oxidize manganese in the oxygen-free brine pool
• Metal concentrations in sediments exceed background by over 100x
• Similar signatures found in an extinct brine pool 1,400 m deep
• Study used metagenomics and metatranscriptomics on sediments