Influence of Substratum Wettability on Attachment of Freshwater Bacteria to Solid Surfaces

We studied the attachment of a number of freshwater bacteria from River Sowe, Coventry, England, to test substrata. The attachment of each organism to hydrophobic and hydrophilic surfaces was evaluated, and further studies evaluated the attachment of selected isolates to a number of substrata with a range of water wettabilities. The wettability of each substratum was determined by contact angle measurements and was expressed as the work of adhesion (W(A)). No generic pattern of attachment to the test surfaces was found, although the majority of the organisms isolated showed a preference for the hydrophobic surface. A more detailed study of selected isolates showed a relationship between W(A) and number of attached cells. Each bacterium attached in maximum numbers to a surface that was characteristic of that organism and that had a W(A) between 75 and 105 mJ m.