Competitive Interactions in Mixed-Species Biofilms Containing the Marine Bacterium Pseudoalteromonas tunicata

• DOI: 10.1128/aem.71.4.1729-1736.2005
• Publication Date: 2005-04-06T13:23:15Z
• Authors: Dhana Rao; Jeremy S. Webb; Staffan Kjelleberg
• Keywords: Pseudoalteromonas; Extracellular polymeric substance; Marine bacteriophage; Ulva lactuca; Biofouling

Pseudoalteromonas tunicata is a biofilm-forming marine bacterium that often found in association with the surface of eukaryotic organisms. It produces range extracellular inhibitory compounds, including an antibacterial protein (AlpP) thought to be beneficial for P. during competition space and nutrients on surfaces. As part our studies interactions between epiphytic bacterial community plant Ulva lactuca, we investigated hypothesis superior competitor compared other bacteria isolated from plant. A number U. lactuca isolates were (i) identified by 16S rRNA gene sequencing, (ii) characterized production or sensitivity proteins, (iii) labeled fluorescent color tag (either red DsRed green protein). We then grew single- mixed-species biofilms containing glass flow cell reactors. In pure culture, all formed microcolony structures within 72 h. However, biofilms, removed competing strain unless its was relatively insensitive AlpP (Pseudoalteromonas gracilis) produced strong activity against (Roseobacter gallaeciensis). Moreover, biofilm conducted AlpP- mutant indicated less competitive when it introduced into preestablished suggesting has role formation. When single-species allowed form microcolonies before introduction competitor, these coexisted extended periods time they removed. Two (R. gallaeciensis tunicata) competitors this study. Our data suggest dominance can attributed ability organisms rapidly their produce compounds.