A University of Plymouth researcher is part of an international team that has provided new insights into the temperature limits of life beneath the ocean floor.
Dr Hayley Manners, Lecturer in Organic Chemistry, and colleagues from 29 different institutes found single-celled microorganisms living in sediments more than a kilometre into the ocean floor – and at a temperature of 120°C.
The study, published in Science, was carried out during a two-month research expedition in 2016 – in which Dr Manners participated – and forms a part of the work of Expedition 370 of the International Ocean Discovery Program (IODP).
It focused on the Nankai Trough off the coast of Japan, where the deep-sea scientific vessel Chikyu drilled a hole 1,180 meters deep to reach sediment at 120°C.
In detailed analyses of the samples, scientists found the concentration of vegetative cells decreased sharply to a level of less than 100 cells per cubic centimetre of sediment at over 50°C.
However, the concentration of endospores – dormant cells of certain types of bacteria that can reactivate and switch to a live state whenever conditions are favourable again – increases rapidly and reaches a peak at 85°C.
The research was led by scientists at MARUM, the Centre for Marine and Environmental Sciences at the University of Bremen in Germany.