The hydrophobicity of bacteria - an important factor in their initial adhesion at the air-water interface

Bacteria isolated from the surface and the subsurface water at four stations along the Swedish west coast were assessed for their hydrophobicity with hydrophobic interaction chromatography (HIC). The surface bacteria were sampled by the Teflon sheet technique. [3H]-L-leucine metabolically labeled isolates were run on a column packed with Octyl-Sepharose CL-4B gel. The relative hydrophobicity of the bacteria was expressed as the ratio, g/e, between the radioactivity of the gel and the eluate. The results revealed a positive correlation between the degree of enrichment of bacteria at the surface and their hydrophobicity. The subsurface bacteria exhibited a broader spectrum of g/e-values than the surface bacteria. The initial adhesion of bacteria to the surface microlayer depends on several factors of which the hydrophobic interaction may be one of the most important.