The natural and anthropogenic microbiota of Glerá, a sub-arctic river in northeastern Iceland

► Pseudomonads were prominent in the microbial community of Glerá river. ► Other isolates include members of eight classes in five phyla. ► Landfill leachate is diluted by river water past the point of detectability by DGGE. ► Anthropogenic impact was detectable by culture-based methods.