UCLA

Nitro- and amino- aromatics, 2,4-dinitrotoluene (DNT), 2-amino-4-nitrotoluene (ANT), and 2,4-diaminotoluene (DAT) are carcinogens and environmentally persistent pollutants. This research investigated their biodegradation by Phanerochaete chrysosporium, natural manganese peroxidase (nMnP), and vault-packaged manganese peroxidase (vMnP). Encapsulation of MnP in ribonucleoprotein nanoparticle cages, called vaults, increased the stability of MnP in reactive conditions by localized concentration. P. chrysosporium removed 25-30% of DNT and ANT within 120 hours. Both vMnP and nMnP catalyzed 73% removal of ANT in-vitro, which indicates that vault packaging did not limit substrate diffusion. This study is also the first report of DAT degradation by MnP. ANT and DAT were not significantly biodegraded by nMnP, but were efficiently degraded even by lower enzyme activities of vMnP. Collectively, these results indicate that fungal enzymes packaged in vault nanoparticles are more stable, concentrated, and active, and they would be effective in biodegradation of energetic compounds in industrial systems and contaminated environments.