No abstract

Temperature not only has direct effects on microbial activity, but can also affect activity indirectly by changing the temperature dependency of the community. This would result in communities performing better over time in response to increased temperatures. We have for the first time studied the effect of soil temperature (5-50 1C) on the community adaptation of both bacterial (leucine incorporation) and fungal growth (acetate-inergosterol incorporation). Growth at different temperatures was estimated after about a month using a short-term assay to avoid confounding the effects of temperature on substrate availability. Before the experiment started, fungal and bacterial growth was optimal around 30 1C. Increasing soil temperature above this resulted in an increase in the optimum for bacterial growth, correlated to soil temperature, with parallel shifts in the total response curve. Below the optimum, soil temperature had only minor effects, although lower temperatures selected for communities growing better at the lowest temperature. Fungi were affected in the same way as bacteria, with large shifts in temperature tolerance at soil temperatures above that of optimum for growth. A simplified technique, only comparing growth at two contrasting temperatures, gave similar results as using a complete temperature curve, allowing for large scale measurements also in field situations with small differences in temperature.

No abstract

No abstract

No abstract

No abstract

No abstract

A three-pronged coordinated research effort was undertaken by cooperating utilities at three different experimental scales investigating bioaugmentation, enrichment and performance of anammox organisms in mainstream treatment. Two major technological components were applied: density-based sludge wasting by a selective cyclone to retain anammox granules and intermittent aeration to repress nitrite oxidizers. This paper evaluates process conditions and operation modes to direct more nitrogen to the resource-saving metabolic route of deammonification.