Bioaugmentation of a historically contaminated soil by polychlorinated biphenyls with Lentinus tigrinus

Microbial Cell Factories

Research

Guglielmo Santi¹  Alessandro D'Annibale¹  Mariangela Giubilei¹  Maurizio Petruccioli¹  Ermanno Federici²  Giulio Zanaroli³  Andrea Negroni³  Fabio Fava³ 

[1] Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, Viterbo, Italy;Department of Cellular and Environmental Biology, University of Perugia, Perugia, Italy;Department of Civil, Environmental and Materials Engineering, Unit of Environmental Biotechnology and Biorefinery, Alma Mater Studiorum, University of Bologna, Bologna, Italy;

关键词: Polychlorinated biphenyls;    Lentinus tigrinus;    Bioaugmentation;    Soybean oil;    Degradation;    Dechlorination;    Biodiversity;    Microbial community structure;   

DOI  :  10.1186/1475-2859-11-35

 received in 2012-01-04, accepted in 2012-03-23,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundSeveral species belonging to the ecological group of white-rot basidiomycetes are able to bring about the remediation of matrices contaminated by a large variety of anthropic organic pollutants. Among them, polychlorobiphenyls (PCBs) are characterized by a high recalcitrance due to both their low bioavailability and the inability of natural microbial communities to degrade them at significant rates and extents. Objective of this study was to assess the impact of a maize stalk-immobilized Lentinus tigrinus CBS 577.79 inoculant combined with soybean oil (SO), as a possible PCB-mobilizing agent, on the bioremediation and resident microbiota of an actual Aroclor 1260 historically contaminated soil under unsaturated solid-phase conditions.ResultsBest overall PCB depletions (33.6 ± 0.3%) and dechlorination (23.2 ± 1.3%) were found after 60 d incubation in the absence of SO where, however, the fungus appeared to exert adverse effects on both the growth of biphenyl- and chlorobenzoate-degrading bacteria and the abundance of genes coding for both biphenyl dioxygenase (bph) and catechol-2,3-dioxygenase. A significant (P < 0.001) linear inverse relationship between depletion yields and degree of chlorination was observed in both augmented and control microcosms in the absence of SO; conversely, this negative correlation was not evident in SO-amended microcosms where the additive inhibited the biodegradation of low chlorinated congeners. The presence of SO, in fact, resulted in lower abundances of both biphenyl-degrading bacteria and bph.ConclusionsThe PCB depletion extents obtained in the presence of L. tigrinus are by far higher than those reported in other remediation studies conducted under unsaturated solid phase conditions on actual site soils historically contaminated by Aroclor 1260. These results suggest that the bioaugmentation strategy with the maize stalk-immobilized mycelium of this species might be promising in the reclamation of PCB-contaminated soils. The addition of SO to matrices contaminated by technical PCB mixtures, such as Aroclor 1242 and Delor 103 and characterized by a large preponderance of low chlorinated congeners, might not be advisable.

【 授权许可】

Unknown   
© Ermanno et al; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.