Microbial reporters of metal bioavailability
Article first published online: 19 FEB 2008
© 2008 The Authors. Journal compilation © 2008 Society for Applied Microbiology and Blackwell Publishing Ltd
Volume 1, Issue 4, pages 320–330, July 2008
How to Cite
Magrisso, S., Erel, Y. and Belkin, S. (2008), Microbial reporters of metal bioavailability. Microbial Biotechnology, 1: 320–330. doi: 10.1111/j.1751-7915.2008.00022.x
- Issue published online: 19 FEB 2008
- Article first published online: 19 FEB 2008
- Received 23 September 2007; revised 16 December 2007; accepted 18 December 2007.
When attempting to assess the extent and the implications of environmental pollution, it is often essential to quantify not only the total concentration of the studied contaminant but also its bioavailable fraction: higher bioavailability, often correlated with increased mobility, signifies enhanced risk but may also facilitate bioremediation. Genetically engineered microorganisms, tailored to respond by a quantifiable signal to the presence of the target chemical(s), may serve as powerful tools for bioavailability assessment. This review summarizes the current knowledge on such microbial bioreporters designed to assay metal bioavailability. Numerous bacterial metal-sensor strains have been developed over the past 15 years, displaying very high detection sensitivities for a broad spectrum of environmentally significant metal targets. These constructs are based on the use of a relatively small number of gene promoters as the sensing elements, and an even smaller selection of molecular reporter systems; they comprise a potentially useful panel of tools for simple and cost-effective determination of the bioavailability of heavy metals in the environment, and for the quantification of the non-bioavailable fraction of the pollutant. In spite of their inherent advantages, however, these tools have not yet been put to actual use in the evaluation of metal bioavailability in a real environmental remediation scheme. For this to happen, acceptance by regulatory authorities is essential, as is a standardization of assay conditions.