Characterization of Hydrophobic Stream Bacteria Based on Adhesion to n-Octane

The purpose of this study was to characterize stream bacterial communities based on cell surface hydrophobicity. Because hydrophobicity is related to adhesion we hypothesized that more hydrophobic bacteria would be found on solid surfaces than in water. Water, rock, and sediment from two northeastern Ohio streams weresampled and bacteria were plated on modified nutrient agar. Hydrophobicity was determined by measuring adherence to n-octane. No difference was found in theproportion of hydrophobic bacteria among habitats. Two hydrophobic isolates were identified as Sphingomonas paucimobilis and Chryseomonas luteola. A largeproportion of hydrophobic bacteria were gram positive and urease positive; none were gelatinase positive. More hydrophobic than hydrophilic bacteria were able to grow using manatose or malatose as the only carbon source. These physiological differences indicate that hydrophobic bacteria may be able to utilize resources not available to hydrophilic bacteria.