Conversion of DMS and MT and formation of methane by 9-ml cell suspension samples taken from the chemostat amended with methanol (A, C, and E) or DMS (B, D, and F) and incubated in 60-ml serum bottles. Symbols: ■, controls containing methanol or DMS; ▴, samples containing methanol plus MT or DMS plus MT; ⧫, samples containing methanol plus Na2S or DMS plus Na2S.