Algal Metabolism

Abstract

Algal metabolism concerns the biochemical and transport processes by which algae take up nutrients and convert them into the materials needed for growth, reproduction and defence of the organisms. Many of the metabolic processes that occur in algae are common to those found in other living organisms. This commonality is described, but emphasis is given to those major metabolic processes in algae that are unique to, or differ in detail from, those of other organisms. This includes mechanisms of light harvesting, carbon acquisition and aspects of nitrogen (N) and sulfur (S) assimilation as well as formation of unique secondary metabolites. In addition the consequences of growth in extreme environments, such as nutrient limitation and exposure to extremes of visible and UV light, for algal metabolism are considered. The exploitation of algal metabolism and its products in biotechnology is also briefly described.

Key Concepts:

  • Algal metabolism shares many features in common with that of other living organisms but also differs in unique respects.

  • Algal metabolism gives rise to a range of unique compounds, including secondary metabolites, some of which have toxicity to other organisms.

  • Algal metabolism is modulated to a large extent by environmental factors such as nutrient availability and extremes of temperature and light.

  • Algal metabolism can be exploited to produce compounds of biotechnological importance. These include pigments, nutraceuticals and oils for biodiesel.

Keywords: algae; biochemistry; extreme environments; nutrition; photosynthesis

Figure 1.

Outline of the pathways of energy, carbon and oxygen in photosynthesis, photorespiration, dark respiration and growth of an alga. No attempt is made to represent stoichiometries. (Abbreviations: Glyc, glycolate; PCOC, photorespiratory carbon fixation cycle (or its equivalent); PCRC, photosynthetic carbon reduction cycle; PGA, 3‐phosphoglycerate; Pglyc, phosphoglycolate; RuBP, ribulose bisphosphate; Rubisco, ribulose bisphosphate carboxylase‐oxygenase.) (Adapted from Raven, .)

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Further Reading

Blankenship RE (2002) Molecular Mechanisms of Photosynthesis. Oxford: Wiley‐Blackwell.

van den Hoek C, Mann DG and Jahns HM (1995) Algae. An Introduction to Phycology. Cambridge: Cambridge University Press.

Larkum AWD, Raven JA and Douglas SE (2002) Photosynthesis in the Algae. In: Govindjee (Series ed.) Advances in Photosynthesis. Dordrecht: Kluwer Academic Publishers.

Lobban CS and Harrison PJ (1997) Seaweed Ecology and Physiology. Cambridge: Cambridge University Press.

Lüning K (1990) Seaweeds. Their Environment, Biogeography and Ecophysiology. New York: John Wiley.

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How to Cite close
Beardall, John, and Raven, John A(Jan 2012) Algal Metabolism. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0000321.pub2]