FIG. 1.

Biofilm formation in microtiter wells by the 17 epiphytic isolates (including Pseudoalteromonas tunicata) isolated from the marine alga Ulva australis. After 24 h of incubation, the biofilm formation was quantified by staining with crystal violet followed by spectrophotometric absorbance measurements (OD₆₀₀). The ratio of biofilm absorbance/planktonic absorbance was calculated, and this value is presented as the “biofilm formation” on the y axis. Isolates with a biofilm formation of less than 2 (indicated by a line) were chosen for further studies on interactions in biofilms. Bars represent means ± standard errors for four replicates.