A vent microbe grew at pH 11 in an Enceladus brine
Methanothermococcus okinawensis, a methane-producing microbe that lives at hydrothermal vents of the Okinawa Trough, grew at a pH as high as 11 in salty, alkaline water built to imitate the ocean of Saturn's moon Enceladus. The experiment lasted days. According to David Rothery of the Open University, one more obstacle to microbial life there looks lower; life there remains a separate question.
Science··Morning
The vent microbe grew at pH 11
Methanothermococcus okinawensis, a methane-producing microbe that lives at hydrothermal vents of the Okinawa Trough, grew at a pH as high as 11 in salty, alkaline water built to imitate the ocean of Saturn's moon Enceladus. On the pH scale 7 is neutral; 11 is a strongly basic environment. According to William Orsi, who works at Ludwig Maximilian University in Munich, the microbe went past its known pH limit. Enceladus has a salty ocean beneath its icy surface, and the moon is one of the leading places where life is sought in space.[1]
Hydrogen came out of rock and water
Orsi's group mixed water, salts, carbonates and powdered rock to imitate the seafloor. Hydrogen appeared as the rock and the water reacted. The microbe makes its living by converting hydrogen and carbon dioxide into methane. The run lasted only days, Orsi said. Methanogens are microbes that live without oxygen and produce methane.[1]
Life on the moon is still a separate question
According to David Rothery, a scientist at the Open University, the work lowers one more obstacle to microbes living on Enceladus. The result does not show that life exists in the moon's ocean; it shows only that this microbe can grow in water that alkaline. The study is published in Science Advances. The experiment ran only for days; whether the microbe could live in those conditions for long is open.[1]
Related columns
For more information on this topic, you can read the related columns.
