Vergani, L., F. Mapelli, J. Suman, T. Cajthaml, O. Uhlik, and S. Borin.
PLoS ONE 14(8): e0221253(2020)

Rhizoremediation was investigated as a method to treat PCB-contaminated soil from the highly polluted SIN Brescia-Caffaro site in Italy using bacterial strains with the potential to degrade PCBs as well as promote plant and root development. Aerobic bacteria from the site were biostimulated by the plant Phalaris arundinacea. The isolated strains, selected based on their ability to grow on biphenyl and plant secondary metabolites, were largely dominated by Actinobacteria, and a significant number showed traits of interest for remediation, harboring genes homologous to bphA involved in the PCB oxidation pathway and displaying 2,3-catechol dioxygenase activity and emulsification properties. Several strains also showed the potential to alleviate plant stress through 1-aminocyclopropane-1-carboxylate deaminase activity. In particular, three Rhodococcus strains were identified that were able to degrade several PCB congeners in vitro and to promote lateral root emergence in the model plant Arabidopsis thaliana in vivo. These strains also showed the capacity to colonize the root system and to increase the plant biomass in PCB contaminated soil, making them ideal candidates to sustain microbial-assisted PCB rhizoremediation through a bioaugmentation approach. https://journals.plos.org/plosone/article/file?type=printable&id=10.1371/journal.pone.0221253