What do we mean by metabolism?

Socio-Economic Metabolism

With increasing development of metabolic engineering in biotechnology and molecular biology – see for example the journal, Metabolic Engineering – our community needs to delve deeper and elaborate our conception of metabolism as it is applied to material flows.  Metabolic engineering, in the words of Wikipedia, is the ‘practice of optimizing genetic and regulatory processes within cells to increase the cells’ production of a certain substance’ and intersects the environmental arena in such areas as biofuels and bioplastics.  It’s not inconceivable that we will see a substance flow analysis (SFA) performed on a substance developed through metabolic engineering in the near future.


The potential confusion of terminology, though, is not a critical issue.  Multiple and differing uses of the same term in various fields is a familiar problem.  What is more important is that the development gives us a prod to further develop our conception of metabolism.  In 2004, I published an editorial ‘Probing Metabolism’ that sketched some questions that might be pursued in this regard.  In the forthcoming issue of the JIE, a literature review of ‘urban metabolism’ provides an especially interesting comparison of how the notion of urban metabolism has been used in industrial ecology, urban ecology, ecological economics, political ecology, and political economy.  Contributions to the JIE that reflect on how we have used the notion of metabolism and how the notion might be further developed or refined would be most welcome.


Castan Broto, V., Allen, A.; and Rapoport, E.  2012. Interdisciplinary perspectives on urban metabolism.  Journal of Industrial Ecology.  16:6. In press.


Lifset, R. 2004. Probing metabolism. Journal of Industrial Ecology 8(3): 1-3. http://dx.doi.org/doi:10.1162/1088198042442315


Reid Lifset

Editor-in-chief, Journal of Industrial Ecology