摘要：The factors affecting prokaryotic and virus structure dynamics and bacterial community composition (BCC) in aquatic habitats along a ca. 1500 m of the Brattegg Valley lake–stream system (SW Spitsbergen) composed of three postglacial lakes created by Brattegg Glacier meltwater were examined. A high number of small-volume prokaryotic cells were found in the recently-formed, deep, upper, subglacial lake. Bacterial taxonomic diversity assessed by PCR-DGGE indicated that the lakes’ BCC differed; with its richness decreasing down the system. Fluorescence in situ hybridisation (FISH) revealed a BCC increase; mainly in α-Proteobacteria, Cytophaga/Flavobacterium and Actinobacteria. We found increasing β-Proteobacteria and Actinobacteria numbers and a decrease in α-Proteobacteria down the system. Our results indicate that glacial meltwater sustains an active bacterial community which is then stimulated or partly eliminated by the proglacial lakes’ higher temperature and nutrient input. We conclude that the prokaryotic succession along this lake–stream system occurs through changes in the structure of dominant bacterial communities, their replacement and elimination.
