Microbes and Metabolism

Microbes and Metabolism

So fundamental are the concepts of cell growth and metabolic capability to the whole of environmental biotechnology and especially to remediation. Metabolic pathways (Michal 1992) are interlinked to produce what can develop into an extraordinarily complicated net-work, involving several levels of control. However, they are fundamentally about the interaction of natural cycles and represent the biological element of the nat-ural geobiological cycles. These impinge on all aspects of the environment, both living and nonliving. Using the carbon cycle as an example, carbon dioxide in the atmosphere is returned by dissolution in rainwater, and also by the process of photosynthesis to produce sugars, which are eventually metabolised to liberate the carbon once more. In addition to constant recycling through metabolic pathways, carbon is also sequestered in living and nonliving components such as in trees in the relatively short term, and deep ocean systems or ancient deposits, such as carbonaceous rocks, in the long term. Cycles which involve similar principles of incorporation into biological molecules and subsequent re-release into the envi-ronment operate for nitrogen, phosphorus and sulphur. All of these overlap in some way, to produce the metabolic pathways responsible for the synthesis and degradation of biomolecules. Superimposed, is an energy cycle, ultimately driven by the sun, and involving constant consumption and release of metabolic energy.

 To appreciate the biochemical basis and underlying genetics of environmental biotechnology, at least an elementary grasp of molecular biology is required. For the benefit of readers unfamiliar with these disciplines, background information is incorporated in appropriate figures.