Bacterial Enhancement of Vinyl Fouling by Algae

The role of bacteria in the development of algae on low-density vinyl was investigated. Unidentified bacterial contaminants in unialgal stock cultures of Phormidium faveolarum and Pleurochloris pyrenoidosa enhanced, by 1 to 2 orders of magnitude, colonization of vinyl by these algae, as determined by epifluorescence microscopy counts and chlorophyll a in extracts of colonized vinyl. Colonization by bacteria always preceded that by algae. Scanning electron microscopy of the colonized Phormidium-bacteria mixture revealed the presence of a slime matrix engulfing both bacteria and algae that may have facilitated algal attachment. Slime was not evident in the Pleurochloris-bacteria mixture, suggesting that the attachment mechanisms differ for the two algae.