Bioremediation of Industrial Pollutants by Insects Expressing a Fungal Laccase

Inadequate management
of household and industrial wastes poses
major challenges to human and environmental health. Advances in synthetic
biology may help address these challenges by engineering biological
systems to perform new functions such as biomanufacturing of high-value
compounds from low-value waste streams and bioremediation of industrial
pollutants. The current emphasis on microbial systems for biomanufacturing,
which often requires highly preprocessed inputs and sophisticated
infrastructure, is not feasible for many waste streams. Furthermore,
concerns about transgene biocontainment have limited the release of
engineered microbes or plants for bioremediation. Engineering of animals
may provide opportunities for utilizing various waste streams that
are not suitable for microbial biomanufacturing while effective transgene
biocontainment options should enable in situ bioremediation.
Here, we engineer the model insect Drosophila melanogaster to express a functional laccase from the fungus Trametes
trogii. Laccase-expressing flies reduced concentrations
of the endocrine disruptor bisphenol A by more than 50% when present
in their growth media. A lyophilized powder prepared from engineered
adult flies retained substantial enzymatic activity, degrading more
than 90% of bisphenol A and the textile dye indigo carmine in aqueous
solutions. Our results demonstrate that transgenic animals may be
used to bioremediate environmental contaminants in vivo and serve as novel production platforms for industrial enzymes.
These results support further development of insects, and possibly
other animals, as bioproduction platforms and their potential use
in bioremediation.