A NEW GROWTH FACTOR REQUIRED BY BUTYRIBACTERIUM RETTGERI

Publisher Website
Google Scholar
Abstract
For growth on a medium containing lactate as the fermentable C source, B. rettgeri requires a new factor which is not replaceable by any of known composition or by strepogenin and vitamin B12. For the assay of the new factor a synthetic medium was devised which permitted comparable growth when supplemented with either 5-10 mg. of a crude source (such as yeast extract) or 1-5 [mu]g. of a purified prepn. per 10 ml. of medium. The factor occurs largely in the bound form and is liberated by autoclaving in I N acid or alkali. It is stable to enzymes, heat, acid, and alkali and partitions readily into a number of immiscible organic solvents. The effect of pH upon the extraction of the activity from aqueous soln. suggests that it is a weak acid with pKa close to 5.2.