Testing your rotten organics

Tobacco skyWill your molecules rot, is biodegradability an intrinsic property of those chemicals you handle on a daily basis? A study published today in the journal Molecular Systems Biology reveals whether or not thousands of chemicals will be biodegradable. The work could help in environmental risk assessment of production, transportation and disposal of organic compounds.

Biodegradability is determined primarily by whether or not there are microbes in the environment that can diget any given compound. Victor de Lorenzo and colleagues at the National Biotechnology Centre in Madrid, Spain, used a database of all known microbial metabolic reactions to train a computer algorithm to distinguish between the biodegradable from the recalcitrant compounds. With this in silico test kit they looked at almost 10000 chemicals.

This automatic predictive approach to assessing biodegradability could help researchers evaluate the potential of new compounds to pollute the environment and help in the implementation of international regulations on the use of new chemicals.

Perhaps not surprisingly, the press release associated with this work focused on those compounds, including herbicides, that are most resistant to biodegradation, but fails to mention the even larger group of compounds that are intrinsically biodegradable. The usual news write-ups about toxic chemicals and the environment 9999 times out of 10000 will inevitably highlight those that are the nastiest.

The huge benefits of the thousands of organic compounds used in the pharma, biotech, plastics, and other industries as well as medicine and agriculture will simply be ignored whether or not those compounds accumulate in the environment or not. Biodegradation is only one route by which thousands of compounds are destroyed naturally in the environment (heat, light and interaction with other non-living materials, are others). The predictive system will be useful, certainly, but its wider applicability should consider these other routes and the risk factors and toxicity associated with any particular chemical, rather than tarnishing all entries in the database simply on the basis of whether or not a microbial enzyme exists to digest it.

The original research paper can be read here.