Many aspects of the flux of dissolved organic carbon (DOC) through
bacteria is poorly understood for both marine and freshwater environments.
Recent experimental work suggests that chemically complex pools of DOC are
composed of compounds with a range of biodegradability, and that some
fractions, traditionally viewed as highly refractory, may be taken up by
bacteria on biologically relevant time scales.  Rates and kinetic patterns
of uptake of compounds from these complex pools are predictably diverse. 
Bacterial uptake of simple compounds from bulk DOC is likewise kinetically
diverse.  Experimental evidence suggests that bacteria utilize multiple
uptake strategies which maximize potential carbon and energy flow as
substrate concentrations vary both spatially and temporally.