Bacterial degradation of nicotinic acid.

Abstract

A BACTERIUM utilizing nicotinic acid was isolated from culture media made up of a solution of nicotinic acid and dilute sodium sulphide and inoculated with a small amount of Potomac mud. After allowing the bacteria to grow anaerobically, several successive transfers were made into a medium containing nicotinic acid, peptone, yeast extract, metals, phosphate and sodium sulphide. The mixed bacterial suspension was then serially diluted in agar media of the same composition under anaerobic conditions. This serial dilution was repeated until the bacterium utilizing nicotinic acid was isolated in pure culture. By this enrichment culture technique, an anaerobic spore-forming rod was isolated which ferments nicotinic acid and which utilizes high concentrations of this compound for its growth. Maximum growth is achieved in the presence of 0.6 per cent yeast extract, 0.2 per cent peptone and 0.4 per cent nicotinic acid. No growth occurs with yeast extract and peptone alone. Neither will the bacterium grow on nicotinic acid as a sole source of carbon.