Influence of redox potential on biomethanation of h2 and co2by methanobacterium thermoautotrophicum in eh-stat batch cultures

Abstract

The influence of redox potential (Eh) on biomethanation from H2and CO2 by Methanobacterium thermoautotrophicum Δ H was studied in pH-controlled anaerobic batch cultures at 65°C in which the Eh of the culture medium was regulated by the addition of titanium(III)-citrate or potassium ferricyanide at values ranging from —315 to —500 mV. The specific growth rate μ and the specific methane production rate Qch4Were Optimum under the Eh range from —370 to —500 mV, while it sharply decreased at the higher Eh range of —315 to —350 mV. The maximum values of Qch4And μ under the optimum environments were 5 (l CH4) (g cell)-1 hr-1 and 0.36hr-1, respectively. © 1987, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation. All rights reserved.