Adsorption of coliphages T1 and T7 to host and non-host microbes and to clay minerals

Abstract

The clay minerals, kaolinite (K) and montmorillonite (M), suspended in either distilled water (DW) or a minimal medium (M-9), were better adsorbents for coliphages T1 or T7 than were bacteria (including early log, late log, or stationary phase cultures of the hosts), actinomycetes, and yeasts. Except for the host bacteria, the microbial cells (regardless of their type, phase of growth, viability, weight or number of cells, and volume of the suspension medium) adsorbed few or no coliphages. Although early log phase cultures (3 h) ofEscherichia coli B, suspended in DW, adsorbed an appreciable amount of T1 (94%), washing the cells with DW reduced the amount of T1 adsorbed (48%); 3-h cultures ofE. coli B/1,5, suspended in DW, adsorbed 15% of a T7 inoculum, and washing the cells with DW reduced the amount of T7 adsorbed to 1%. There was appreciable adsorption (35 to 97%) of both coliphages (with the exception of T1 on K) to 1 mg K or M suspended in either DW or M-9. These results suggest that clays are more important than microbes as adsorbents of viruses in environments of low ionic strength and that microbes do not inactivate coliphages T1 and T7.