sentences:  During the war the Allies needed pure acetone as a solvent for nitro-cellulose, a highly flammable compound that is the main component in gunpowder.In 1916, biochemist and future first president of Israel Chaim Weizmann was the first to isolate "Clostridium acetobutylicum", a Gram-positive, anaerobic bacteria in which acetoacetate decarboxylase is found.Weizmann was able to harness the organism's ability to yield acetone from starch in order to mass-produce explosives during the war.