Influence of redox potential on methanation of methanol by Methanosarcina barkeri in Eh-stat batch cultures

Abstract

The effect of Eh on the methanogenesis of methanol by Methanosarcina barkeri strain Fusaro was studied in pH-controlled anaerobic batch cultures at 37°C, in which the Eh of the culture medium was controlled by the addition of Ti(III)-citrate at values ranging from −340 to −520 mV. The changes in Eh revealed that the specific growth rate, μ, specific methane production rate, Q CH 4 and growth yield, Y X/S were optimum under an Eh between −430 and −520 mV, while they decreased at the higher Eh of −340 mV. The maximum values of Q CH 4 and μ under the optimum Eh condition were 210 ml CH 4/g dry cell weight·h −1 and 0.11 h −1, respectively.