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Effects of resource chemistry on the composition and function of stream hyporheic biofilms.

February 1, 2012

Fluvial ecosystems process large quantities of dissolved organic matter as it moves from the headwater streams to the sea. In particular, hyporheic sediments are centers of high biogeochemical reactivity due to their elevated residence time and high microbial biomass and activity. However, the interaction between organic matter and microbial dynamics in the hyporheic zone remains poorly understood. We evaluated how variance in resource chemistry affected the microbial community and its associated activity in experimentally grown hyporheic biofilms. To do this we fed beech leaf leachates that differed in chemical composition to a series of bioreactors filled with sediment from a sub-alpine stream. Differences in resource chemistry resulted in differences in diversity and phylogenetic origin of microbial proteins, enzyme activity, and microbial biomass stoichiometry. Specifically, increased lignin, phenolics, and manganese in a single leachate resulted in increased phenoloxidase and peroxidase activity, elevated microbial biomass carbon:nitrogen ratio, and a greater proportion of proteins of Betaproteobacteria origin. We used this model system to attempt to link microbial form (community composition and metaproteome) with function (enzyme activity) in order to better understand the mechanisms that link resource heterogeneity to ecosystem function in stream ecosystems.

Citation Information

Publication Year 2012
Title Effects of resource chemistry on the composition and function of stream hyporheic biofilms.
DOI 10.3389/fmicb.2012.00035
Authors E. K. Hall, K. Besemer, L. Kohl, C. Preiler, K. Reidel, T. Schneider, W. Wanek, T.J. Battin
Publication Type Article
Publication Subtype Journal Article
Series Title Frontiers in Microbiology
Series Number
Index ID 70118124
Record Source USGS Publications Warehouse
USGS Organization