title: A comparison of the response of two Burkholderia fungorum strains grown as planktonic cells versus biofilm to dibenzothiophene and select polycyclic aromatic hydrocarbons.
abstract: In natural environments, bacteria often exist in close association with surfaces and interfaces by establishing biofilms. Here, we report on the ability of Burkholderia fungorum strains DBT1 and 95 to survive in high concentrations of hydrocarbons, and we compare their growth as a biofilm vs. planktonic cells. The 2 compounds tested were dibenzothiophene (DBT) and a mixture of naphthalene, phenanthrene, and pyrene (5:2:1) as representative compounds of thiophenes and polycyclic aromatic hydrocarbons (PAHs), respectively. The results showed that both strains were able to degrade DBT and to survive in the presence of up to a 2000 mg·L-1concentration of this compound both as a biofilm and as free-living cells. Moreover, B. fungorum DBT1 showed reduced tolerance towards the mixed PAHs (2000 mg·L-1naphthalene, 800 mg·L-1phenanthrene, and 400 mg·L-1pyrene) both as a biofilm and as free-living cells. Conversely, biofilms of B. fungorum 95 enhanced resistance against these toxic compounds compared with planktonic cells (P < 0.05). Visual observation through confocal laser scanning microscopy showed that exposure of biofilms to DBT and PAHs altered their structure: high concentrations of DBT triggered an aggregation of biofilm cells. These findings provide new perspectives on the effectiveness of using DBT-degrading bacterial strains in bioremediation of hydrocarbon-contaminated sites.
authors: a Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors: Nazanin Seyed
authors: NS
authors: Khoei
authors: a Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors: Marco
authors: M
authors: Andreolli
authors: a Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors: Silvia
authors: S
authors: Lampis
authors: a Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
authors: Giovanni
authors: G
authors: Vallini
authors: b Biofilm Research Group, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.
authors: Raymond J
authors: RJ
authors: Turner
mesh_terms: D001673:Biodegradation, Environmental; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D019117:Burkholderia / Q000187:drug effects / Q000254:growth & development*; D050296:Microbial Viability; D010933:Plankton / Q000187:drug effects / Q000254:growth & development; D011084:Polycyclic Aromatic Hydrocarbons / Q000494:pharmacology*; D012989:Soil Pollutants / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants; D013876:Thiophenes; C016366:dibenzothiophene
keywords: Burkholderia fungorum; biofilm; bioremediation; biorestauration; dibenzothiophene; dibenzothiophène; hydrocarbures aromatiques polycycliques; polycyclic aromatic hydrocarbons