Figure 3.

Gas-chromatographic tracings show the concentrations of sulfur-containing gases in the gas space before and after a 60-minute incubation of cecal homogenate with a gas space initially containing H₂S. In contrast to the studies shown in Figures 1 and 2, in this study the buffer was supplemented with the methyl donor S-adenosylmethionine. Similarly attenuated measurements of the sulfur gas concentrations present at 0 and 60 minutes are shown in a and b, respectively. Most of the H₂S had been metabolized by 60 minutes, with no evidence of CH₃SH or CH₃SCH₃ production (b). (c) The same recording shown in b, with the attenuation reduced by 16-fold. Even with 16-fold “magnification,” no CH₃SH nor CH₃SCH₃ evolution could be identified.