Effect of Nickel Levels on Hydrogen Partial Pressure and Methane Production in Methanogens - Fig 3

<p>Hydrogen partial pressure (_pH₂, Pa) during growth of a) M. bourgensis MAB1, b) M. barkeri and c) M. bryantii, plotted as a function of time. A refill of H₂/CO₂ (1 atm, 20:80) was made before the fifth sampling point (i.e. after 68 days of incubation).