Novel PCB-degrading Rhodococcus strains able to promote plant growth for assisted rhizoremediation of historically polluted soils

0518271 - MBÚ 2020 RIV US eng J - Journal Article
Vergani, L. - Mapelli, F. - Šuman, J. - Cajthaml, Tomáš - Uhlík, O. - Borin, S.
Novel PCB-degrading Rhodococcus strains able to promote plant growth for assisted rhizoremediation of historically polluted soils.
PLoS ONE. Roč. 14, č. 8 (2019), č. článku e0221253. ISSN 1932-6203. E-ISSN 1932-6203
Institutional support: RVO:61388971
Keywords : polychlorinated-biphenyls pcbs * contaminated soils * bioremediation
OECD category: Microbiology
Impact factor: 2.740, year: 2019
Method of publishing: Open access
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0221253

Extended soil contamination by polychlorinated biphenyls (PCBs) represents a global environmental issue that can hardly be addressed with the conventional remediation treatments. Rhizoremediation is a sustainable alternative, exploiting plants to stimulate in situ the degradative bacterial communities naturally occurring in historically polluted areas. This approach can be enhanced by the use of bacterial strains that combine PCB degradation potential with the ability to promote plant and root development. With this aim, we established a collection of aerobic bacteria isolated from the soil of the highly PCB-polluted site 'SIN Brescia-Caffaro' (Italy) biostimulated by the plant Phalaris arundinacea. The strains, selected on biphenyl and plant secondary metabolites provided as unique carbon source, were largely dominated by Actinobacteria and a significant number showed traits of interest for remediation, harbouring 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, we identified three Rhodococcus strains able to degrade in vitro several PCB congeners and to promote lateral root emergence in the model plant Arabidopsis thaliana in vivo. In addition, these strains 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.
Permanent Link: http://hdl.handle.net/11104/0303441