Interaction between organisms and abiotic

INTERACTIONS BETWEEN ORGANISMS AND ABIOTIC ENVIRONMENT REDFIELD STOICfflOMETRY... 

The integration of biotic and abiotic dynamics also needs to take into account interactions between organisms and chemical properties of the environment, which are stmctured, not only by the synthesis of metabolites, but also by local disturbances of the physicochemical equilibria. The study of organic matter degradation processes, in the form of particulate or macrodebris, in benthic marine enviromnents, combined with that of community diversity and d5rnamic, helps illustrate this integration. 

Interactions between plants and microorganisms in remediation must be studied further and with greater attention, because in many contaminated sites they both can be beneficial if applied simultaneously, and synergy may enhance the individual site cleanup and reduce costs.. This holistic approach considers interactions in the environment, not only between organisms, but also between contaminants, and between biotic and abiotic factors. 

The environmental interactions of CdSe QDs in abiotic environments are expected to be enhanced in biological environments due to the presence of biofilms (89). Biofilms are bacterial cells attached to surfaces where the cells multiply and produce extracellular polymeric substances (EPS) (90). Thus, a biofilm is a combination of cells, polysaccharides, nucleic acids, proteins, and inorganic material that may form structured channels (91, 92). The biophysiochemical interactions between biofilms and CdSe QDs can include binding and uptake, decomposition, and expulsion. These processes may have toxic repercussions for biological organisms. 

In natural waters organisms and their abiotic environment are interrelated and interact upon each other. Such ecological systems are never in equilibrium because of the continuous input of solar energy (photosynthesis) necessary to maintain life. Free energy concepts can only describe the thermodynamically stable state and characterize the direction and extent of processes that are approaching equilibrium. Discrepancies between predicted equilibrium calculations and the available data of the real systems give valuable insight into those cases where chemical reactions are not understood sufficiently, where nonequilibrium conditions prevail, or where the analytical data are not sufficiently accurate or specific. Such discrepancies thus provide an incentive for future research and the development of more refined models. 

Metalloreceptors, and the supermolecules that they form, thus open up a vast area for the study of interactions and reactions between simultaneously co-bound organic and inorganic species [4.67,4.68]. In view of the number of metal-ion complexes known and of the various potential molecular substrates, numerous types of metalloreceptors may be imagined that would be of interest as abiotic chemical species or as bioinorganic model systems. 

---