a51 0. | Oxidation of Phenol by Certain Bacteria. 155 
_ Four hundred cubic centimetres of this solution were sterilised in a litre 
flask, plugged with cotton wool, in a steam steriliser for three successive 
days. When sterile, a few drops of a broth culture of the organism 
were added, particular care being taken to prevent contamination. It was 
intended to limit the amount of carbon in the media, it being supposed that 
the phenol on oxidation would supply the deficiency. 
The flask and contents were incubated for several days at 20° C., the liquid 
being aérated by an occasional shake. The solution was tested after five 
days with the usual precaution to prevent contamination. 
Results :— 
Oxygen absorbed from acid 
permanganate in 3 minutes. 
Parts per 100,000. 
At Commencement ............c.00s 19°20* 
AdGER OF CAS hrie.§ wctncnempemess ved ac 8°57 
Pr a) eh Wile CRA RA Oc), eee 1°83 
¥ Equivalent to 12°5 parts of phenol per 100,000. 
On the ninth day, before submitting the solution to chemical tests, gelatine 
plates were made. Two plates were made taking 1 c.c. of the liquid, and one 
plate each for 0°01 cc., 0°0001 c.c., and 0°000001 c.c. 
Bacteriological Results (3 days at 20° C.). 
esc. original, 2 plates ...... Crowded with organisms. All one kind. No lique- 
| fying colonies. 
0°01 c.c. m 1 Ape Me Crowded. All one kind. Chromogenic. 
0:0001 c.c. S tL Pals eee Senet Hundreds of colonies. All one kind. Chromogenic. 
0000001 «ec. ,, Ty ost hs 130 colonies. Chromogenic. All one kind. 
The solution contained 130,000,000 organisms per cubic centimetre, and 
there was not the slightest evidence of contamination. It may be safely 
concluded, therefore, that dilute solutions of phenol are oxidised by the 
particular organism under investigation. 
Experiments are being carried out to determine the exact effect upon the 
oxidation of phenol by this organism, of the addition of other nutrient 
substances, Experiment II (0) having shown team the addition of broth 
accelerated the action. 
Researches have also been in progress on the bacterial oxidation of 
sulphocyanates, which appears to be more complex, and certainly less rapidly 
effected than the oxidation of phenol, inasmuch as when a mixture of the 
two substances is submitted to bacterial oxidation the phenol is invariably 
the first to disappear. 
