▁Pr ont os il , ▁was ▁developed ▁by ▁a ▁research ▁team ▁led ▁by ▁Ger hard ▁Dom ag k ▁in ▁ 1 9 3 2 ▁or ▁ 1 9 3 3 ▁at ▁the ▁Bayer ▁Labor ator ies ▁of ▁the ▁I G ▁Far ben ▁con gl omer ate ▁in ▁Germany , ▁for ▁which ▁Dom ag k ▁received ▁the ▁ 1 9 3 9 ▁Nobel ▁Prize ▁in ▁Phys i ology ▁or ▁Medicine . ▁Sul fan il am ide , ▁the ▁active ▁drug ▁of ▁Pr ont os il , ▁was ▁not ▁pat ent able ▁as ▁it ▁had ▁already ▁been ▁in ▁use ▁in ▁the ▁d ye ▁industry ▁for ▁some ▁years . ▁Pr ont os il ▁had ▁a ▁relatively ▁broad ▁effect ▁against ▁Gram - pos itive ▁c oc ci , ▁but ▁not ▁against ▁enter ob acter ia . ▁Research ▁was ▁stim ulated ▁ap ace ▁by ▁its ▁success . ▁The ▁discovery ▁and ▁development ▁of ▁this ▁sul fon am ide ▁drug ▁opened ▁the ▁era ▁of ▁ant ib acter ial s . ▁ ▁Pen ic ill in ▁and ▁other ▁natural ▁ant ib iot ics ▁ ▁Observ ations ▁about ▁the ▁growth ▁of ▁some ▁micro organ isms ▁in hib iting ▁the ▁growth ▁of ▁other ▁micro organ isms ▁have ▁been ▁reported ▁since ▁the ▁late ▁ 1 9 th ▁century . ▁These ▁observations ▁of ▁ant ib ios is ▁between ▁micro organ isms ▁led ▁to ▁the ▁discovery ▁of ▁natural ▁ant ib acter ial s . ▁Louis ▁P aste ur ▁observed , ▁" if ▁we ▁could ▁interven e ▁in ▁the ▁ant agon ism ▁observed ▁between ▁some ▁b acter