Microbial film formation on metals in an enriched arctic river

Abstract

Attachment of microorganisms to metal surfaces was investigated in a nutrient enriched pristine arctic river. Biofilms were characterised in terms of bacterial population size and metabolic activity. Metals were placed in the river at an untreated and a phosphate + nitrate enriched site. After 25 days, poorly developed bacterial films were formed on stainless steel and titanium surfaces at the control site. However, at the enriched site thick algal/bacterial films developed on both of these metals, as shown by scanning and transmission electron microscopy. The bacteria in these films were highly active, with high levels of polyhydroxy alkanoic acid synthesis. Even after 25 days, adhesion was minimal on copper alloy surfaces at both sites. The data are discussed in relation to the pristine nature of this river system and the implications for eutrophic rivers.