Bacterial Inactivation of Pantothenate

It was found by the use of inhibitors that the circumstance noce.s.sary for nactivation of pantothenate was not only that glucose should be present, but that it should be broken down by the streptococci. The organisms produced from glucose, with or without pantothenate, about 1.9 moles of lactic acid per mole of glucose. Such glycolysis, and pantothenate breakdown, proceeded aerobically or anaerobically, but, when it was inhibited by iodoacetate, benzene, malonate, or propamidine, the reaction with pantothenate was also inhibited. The streptococcal extracts in which pantothenate was stable were also incapable of glycolysis. 

While glycolysis was proceeding at a steady rate, pantothenate inactivation was also nearly proportional to time. This was demonstrated with Streptococus hemolyticus, P. morganii, and C. diphtheriae. The ratio between the two rates was relatively stable. Usually 2500 to 4500 moles of acid were produced from glucose during the inactivation of one mole of pantothenate by streptococci (71) under a variety of conditions. The ratio between the two rates was remarkably similar also, in different organisms. 

Inhibition op Microbial Growth by Substances Structurally Rei.ated 

Ratio (inhibitor concn. /pantothenate concn.) required for inhibition of visible growth for some days 

Leuconostoc mesenteroides Proteus morganii /3-Hemolytio streptococci D. pneumoniae C. diphtheriae 

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