Processes in the Action of Pantothenate on Growth

The effect of pantothenate on microorganisms, which was first observed and in relation to which the majority of the foregoing observations were made, was its action on the over-all process of growth. In the present section further characteristics of growth are described, and it is attempted to link them with the metabolic behavior of pantothenate. Evidence obtained by the use of specific inhibitors related in structure to pantothenate has played a large part in this. 

Its ability to do this varied markedly in different bacterial species. Competitive relationships of the type described above, between pantoyl- 

Pantothenate present initially. MX 10- Pantoyltaurine added, later, M Population siae at time of addn. of pantoyltaurine, mg. dry wt. per 3 ml. medium Time after inoculation at which pantoyltaurine added, min. Period of growth permitted after addn., min. Increase in culture sise permitted (ratio to sise at time of addn.) 

Evidence bearing on the manner in which pantoyltaurine affects growth has been obtained by examining its effects in other reactions between the streptococci and pantothenate, and these effects will now be considered. 

Further examination has shown a close relationship between inhibition of the two processes. In this, first, the action of pantoyltaurine on growth and on the inactivation in a series of organisms was compared. The concentrations of pantoyltaurine required for the inhibition varied widely in different organisms, but in parallel (74). Second, a similarly close 

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