Synthetic biology approaches towards the recycling of metals from the environment

Metals are a finite resource and their demand for use within existing and new technologies
means metal scarcity is increasingly a global challenge. Conversely, there are areas
containing such high levels of metal pollution that they are hazardous to life, and there is
loss of material at every stage of the lifecycle of metals and their products. While traditional
resource extraction methods are becoming less cost effective, due to a lowering
quality of ore, industrial practices have begun turning to newer technologies to tap into
metal resources currently locked up in contaminated land or lost in the extraction and
manufacturing processes. One such technology uses biology for the remediation of
metals, simultaneously extracting resources, decontaminating land, and reducing waste.
Using biology for the identification and recovery of metals is considered a much ‘greener’
alternative to that of chemical methods, and this approach is about to undergo a renaissance
thanks to synthetic biology. Synthetic biology couples molecular genetics with
traditional engineering principles, incorporating a modular and standardised practice into
the assembly of genetic parts. This has allowed the use of non-model organisms in place
of the normal laboratory strains, as well as the adaption of environmentally sourced
genetic material to standardised parts and practices. While synthetic biology is revolutionising
the genetic capability of standard model organisms, there has been limited incursion
into current practices for the biological recovery of metals from environmental
sources. This mini-review will focus on some of the areas that have potential roles to play
in these processes.