Batch cultures were performed for uptake of methanol, and acetate for production of methane and CO2 by Methanosarcina mazei cultures. The growth, substrate consumption, methane and CO2 production characteristics were analysed and compared. The maximum values of specific growth rate, specific rate of substrate consumption from methanol were 0.047-0.084 ha(-1), and 0.37-0.67 g methanol g(-1) cells h(-1) while the values of specific rate of methane and CO2 formation were 13.38-19.99 mM methane g(-1) cells h(-1), and 5.46 m(M) CO2 g(-1) cells h(-1), respectively. Similarly, maximum values of specific growth rate, and specific rate of acetate consumption were 0.059-0.096 h(-1), 0.49-0.74 g acetate g(-1) cells h(-1), respectively, while the values of specific rate of methane and CO2 formation were, 5.30-9.90 mM methane g(-1) cells h(-1), and 5.30-11.0 mM CO2 g(-1) cells h(-1) from its consumption. The values of substrate consumption kinetic parameters are significantly higher than those reported in other studies for Methanosarcina spp. and other acetoclastic methane producers.