Bioreactivity of Dissolved Organic Matter

The strength of the bioassay approach is that it directly estimates the fraction of natural DOC that can be used by a natural microbial assemblage under defined conditions. However, there are numerous manipulations of water samples during bioassay incubations, and the effects of these manipulations on the measured parameters are not well known. For example, containment of water samples can rapidly alter microbial population structure. Nutrients, rather than carbon, can be limiting for microbial utilization of DOM. Moreover, there are no standard protocols for bioassay experiments. Different indicators of DOM utilization are measured by different investigators, and many of the measured parameters rely on conversion factors that are also quite variable. The extent of DOM utilization also depends upon the duration and temperature of the bioassay experiment. Despite these shortcomings, the bioassay experiment remains the best approach for estimating the bioavailability of DOM. 

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IV. RELATIONSHIPS BETWEEN THE CHEMICAL COMPOSITION AND BIOREACTIVITY OF DISSOLVED ORGANIC MATTER... 

Amon, R. M. W., H.-R Fitznar, and R. Benner. 2001. Linkages among the bioreactivity, chemical composition, and diagenetic state of marine dissolved organic matter. Limnology... 

Kramer, G.D. and Hemdl, G.J. (2004). Photo- and bioreactivity of chromophoric dissolved organic matter produced by marine bacterioplankton. Aquat. Microb. Ecol, 36(3), 239-246. 

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