Enzymes in the environment: What do we really know?

Background/Question/Methods

Extracellular enzymes are the proximate agents of organic matter decomposition, and are critical for biogeochemical cycling in all environments.  Enzyme activities are frequently measured, but do we really know how to interpret them? Despite decades of research, many fundamental questions linger about the controls on enzyme production, stabilization, turnover, and in-situ activity.  This limits our ability to interpret measured enzyme activities in an ecological framework. I will present an overview of current knowledge, misconceptions, and recent advancements as an introduction to our symposium on this topic, organized by the Enzymes in the Environment Research Coordination Network. 

Results/Conclusions

Recent studies have shed new light on the ecology of enzymes in the environment.  Recent emperical evidence supports theories about controls on enzyme production, but also shows some surprising results.  For example, we found that enzyme production decreases with increasing temperature, resulting in no net effect of temperature on decomposition rates during litter decomposition.  New technologies are providing insights into the stabilization and in situ activity of extracellular enzymes.  We recently developed a model to predict in situ enzyme activity based on both temperature and soil moisture. As a result, it is now becoming practical and useful to explicitly incorporate enzymes into models. 

Enabled by new technologies, creative approaches, and building off of important classic studies, scientists from many fields are contributing to a rapidly evolving understanding of the fundamental controls on enzyme production, stabilization, turnover, and in situ activity.  These innovations will be highlighted in this symposium.