Plant-microorganism combined remediation of polychlorinated naphthalenes contaminated soils based on molecular directed transformation and Taguchi experimental design-assisted dynamics simulation.

The molecular directed transformation procedure was adopted by combining molecular docking and homology modeling to reconstruct the proteins, which are involved in the absorption, degradation, and mineralization of polychlorinated naphthalenes (PCNs). A comprehensive evaluation system for developing new proteins that are responsible for the absorption (aquaporin: 1Z98), degradation (peroxidase: 1ATJ), and mineralization (lignin peroxidase: 1B85) of PCNs was established using the Rank Sum Ratio (RSR) and weighted average methods. The Taguchi experimental design-assisted dynamics simulation was used to determine the optimal external stimulus conditions of plant-microorganism combined remediation system to absorb, degrade, and mineralize PCNs. Results showed that a total of 60 amino acid sequences were designed, and 19 new proteins (increasing amplitude: 66.67%-500.00%) were significantly higher than those of target proteins through the screening of comprehensive evaluation system. Additionally, 10 new proteins improved the efficiency of absorption, degradation, and mineralization of PCNs in a real environment which were simulated under the optimal external stimulus conditions. Moreover, remediation efficiency was significantly enhanced when the template proteins was replaced with a combination of 1Z98-9, 1ATJ-7, and 1B85-20 in plant-microorganism systems, and the van der Waals force and polar solvation were the main factors affecting the absorption, degradation, and mineralization of PCNs.