干旱区生态环境知识资源中心

The glacial river Jokulsa a Fjollum, which originates in the Vatnajokull ice cap and flows through a large basaltic tephra desert on its way to discharge into the Arctic Ocean, presents a number of unique microbial habitats heretofore unexplored. We sampled river water, sediment and selected other biotopes at 12 sampling points along the river from source to mouth and generated a collection of 382 purified and confirmed reculturable psychrotrophic bacterial strains. Partial 16S rDNA sequencing yielded 19 genera and 4 non-genus specific assignments in 4 bacterial phyla, with pseudomonads and flavobacteria being particularly well represented. A large portion of the isolates produced extracellular enzymes at 15 degrees C, including amylase, betaglucanase, cellulase, protease and laccase.