Abstract
Effects of sulfur-containing compounds, such as n-butylthiolsulfinic acid ester (B. S. A.), thio-cyanoacetic acid isopropyl ester (SCN-P), thiocyanoacetic acid n-butyl ester (SCN-B) and thio-cyanoacetic acid isoamyl ester (SCN-A) upon the respiration of both E. coli and Sacch. cerevisiae were observed.
The inhibiting effects of all drugs upon E. coli were 54_??_63%, and to Sacch. cerevisiae 85_??_97%. To establish from what cause the decrease of 02 uptake of microbes occurred, the number of active microbes under the same condition of respiratory experiments were counted. B. S. A. combined with the essential SH-radicals of microbes under 20 minutes reaction and inhibited their growth 100%, while SCN-compounds inhibited 30_??_40% under 90 minutes reaction.
In view of the above results it is concluded that the decrease of 02 uptake of resting cell is due to the inhibition of the essential stages in metabolism, which destroys the normal respiration of microbes.
