Cellulose degradation in different types of limnic environments

The decrease in tensile strength of chemically untreated cotton threads that had been exposed at different levels in lake water and lake sediment was investigated. The quotient of the tensile strength before and after exposure was taken as a measure of the potential cellulolytic activity. Two oligotrophic Swedish lakes showed a very weak cellulolytic activity. In the eutrophicated Lake Trummen the activity was high in the summer specially at the sediment-water interface, but low in the winter. During the restoration of this lake by suctiondredging the nutrient-rich sediment up on land, an easily measureable activity could also be detected in the water. The cellulose degradation was also studied in some rivers and streams and in the water of three sewage treatment plants.