Bioremediation of industrial pollutants by insects expressing a fungal laccase

Abstract

Inadequate management of household and industrial wastes pose 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 require highly pre-processed inputs and sophisticated infrastructure, is not feasible for many waste streams. Concerns about transgene biocontainment have limited the release of engineered microbes or plants for bioremediation. Engineering 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 made 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.