Under the microscope: microbial life at pore scale under extreme deep-environment conditions

to reproduce the standard headspace mixture for culture of methanogens. Surprisingly, despite 36 h incubation under these expected favourable conditions, we observe general mortality of both species, except for vigourous population growth of T. atlanticus at a point a few millimetres from the interface with the headspace. The space-time development of the concentrations of dissolved gases and of the pH are modelled in a numerical solution of the diffusion equations. It predicts quasi-stationary conditions at that particular point during the first ≈ 1/2h of incubation.