Micro organisms carbon cycle

The interaction between the carbonate cycle and the organic carbon cycle takes place under a variety of circumstances. At one end of the spectrum, carbonate chemistry may be under direct enzymic control (see Chapter 2.2). It may take place within cells, within organisms, or within micro-environments in close contact with living tissues (e.g., molluscan mantle). At the other extreme, where products of metabolic activities modify the overall chemistry of the environment, carbonate dissolution or precipitation may be influenced indirectly. The closer the contact between the organism and the substrate, the more specific are the biogenic dissolution and crystallization patterns that remain as traces of biological activity in sediments. 

The carbon cycle is not at all dependent on the presence of animals or plants. It could continue in the presence of micro-organisms alone and with special intensity in the oceans where the photosynthesis is eight times more intense than that due to land plants. This marine photosynthesis is due to the presence of Diatoms and the Dinoflagellates of phytoplankton. Figure 100 shows a carbon cycle which is entirely microbial in character. 

Data on the radiocarbon tracer detected in various plant species is shown in Table 12.6. These results confirm that polymer fragments produced by the photodegradation of certain plastic molecules are indeed attacked and metabolized by soil micro-organisms, and are assimilated into the natural carbon cycle. Because radiocarbon assay of the CO2 produced by plant and animal... 

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