A method for the detection of phenols produced by bacteria

Abstract

The method ordinarily used for the detection of phenol is essentially as stated by Eyre.1 The culture is prepared in a flask containing nutrient broth and incubated. After incubation, 5 cc of 25 % sulphuric acid is added to the cultivation, and the flask is connected with a condenser; 15 to 20 cc are distilled over, and the distillate divided into 3 portions, (a), (b) and (c). To {a), 0.5 c c of Millon's reagent is added and the solution is boiled; red color^phenol. To (b), 0.5 cc ferric chlorid solution is added; violet color = phenol. (If the distillate be acid the reaction will be negative.) To (c), bromine water is added; crystalline white precipitate of tribromphenol^:phenol. In case indol and phenol appear to be present in cultivations of the same organism, it is recommended that they be separated before testing. This is done by redistilling the first distillate (which would contain both indol and phenol) after rendering it alkaline with caustic potash. The distillate contains indol, the residue phenol. The residue is saturated with CO 2 and redistilled. The last distillate will contain phenol and is tested as stated in the foregoing. Rettger,2 in his study of the chemical products of B. coli and B. lactis-aerogenes, used a somewhat similar method. The medium used in his experiments was an egg-meat mixture, and incubation was carried on in the presence of hydrogen. Portions of 400 c c of the decomposition mixture were diluted with an equal volume of water, and aftei