The Value of Adsorbents for Detecting Survival in Bacterial Populations Exposed to Phenols

Abstract

Summary The inclusion of 0·1 per cent, of activated charcoal or 0·03 per cent. of ferric chloride in subculture media had no consistent influence on the extinction times of Bact. coli exposed to 1 per cent, phenol, but the overall responses in experiments made with several batches of media were positive. On the whole, individual batches of medium consistently gave the same kind of response, positive or null. Activated charcoal (0·1 per cent.) adsorbed about 80 per cent, of the phenol from solution in water at a concentration of 0·005 per cent. In the presence of broth much less was adsorbed; Norit adsorbed only about 9 per cent, and Darco G 60 about 25 per cent. The ferric chloride-nutrient broth precipitate did not adsorb phenol from either water or broth. 5 In the concentration range 0·001 to 0·020 per cent., phenol in the subculture medium did not appear to influence the extinction times of bacterial populations exposed to that substance.