Soil Enzyme Activity: From Microbial Physiology to Ecosystem Function.

Microbes appear to exercise several extracellular enzyme production-tactics to acquire carbon and nutrients from their environments.  End-product suppression on enzyme production is one of such strategies and explains the negative associations between the activity of soil phosphatases and phosphorus availability and in some cases between the activity of nitrogen-acquiring enzymes and nitrogen availability.  Microbial resource allocation represents another microbial enzyme production strategy and predicts that the activity of soil carbon-mineralization enzymes will increase with nitrogen fertilization or soil phosphorus availability.  Recently, the concept “microbial nitrogen mining” has emerged from the observation that soil phenol oxidase activity is inhibited by increased nitrogen availability.  The ability of mining nitrogen occluded within recalcitrant organics appears to be an important strategy for microbes to generate organic carbon-degrading extracellular enzymes.  There are a number of studies elucidating microbial community physiology for soil enzyme production and its applications for managing soil carbon sequestration and nutrient availability under global environmental change.  This work presents some uncertainty and challenges in applying the principles of soil enzyme production to the management practices in agro- and urban-ecosystems.