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Publications in VIVO

Hobbie, John Distinguished Scientist, Ecosystems Center


My research as an aquatic ecologist has attempted to identify the factors controlling decomposition and productivity within aquatic Ecosystems. I am primarily interested in the role natural assemblages of microbes play in ecosystems. I began studying this problem over 30 years ago in Swedish lakes, where I developed and applied methods for measuring the kinetics of uptake of organic compounds by bacteria using radiolabelled substrates. I later developed methods for measuring the mineralization of organic compounds to CO2, and visualizing and enumerating bacteria present in natural water samples using DNA specific stains (acridine orange and DAPI). The development of molecular biology has allowed us to put specific names on bacteria found in nature and we are attempting to determine what species are present and active seasonally. I also look at larger systems in estuaries and arctic tundra lakes where we have a 20-year data set. The combination of observations and experimental manipulations carried out over many years have proven a valuable tool for understanding ecological processes.

selected publications