Degradation of dibenzofuran via multiple dioxygenation by a newly isolated Agrobacterium sp. PH-08

Abstract

Aims: To demonstrate the biodegradation of dibenzofuran (DF) and its structural analogs by a newly isolated Agrobacterium sp. PH-08. Methods and Results: To assess the biodegradation potential of newly isolated Agrobacterium sp. PH-08, various substrates were evaluated as sole carbon sources in growth and biotransformation experiments. ESI LC-MS/MS analysis revealed the presence of angular degrading by-products as well as lateral dioxygenation metabolites in the upper pathway. The metabolites in the lower pathway also were detected. In addition, the cometabolically degraded daughter compounds of DF-related compounds such as BP and dibenzothiophene (DBT) in dual substrate degradation were observed. Strain PH-08 exhibited the evidence of meta-cleavage pathway as confirmed by the activity and gene expression of catechol-2,3-dioxygenase. Conclusions: Newly isolated bacterial strain, Agrobacterium sp. PH-08, grew well with and degraded DF via both angular and lateral dioxygenation as demonstrated by metabolites identified through ESI LC-MS/MS and GC-MS analyses. The other heterocyclic pollutants were also cometabolically degraded. Significance and Impact of the Study: Few reports have described the complete degradation of DF by a cometabolic lateral pathway. Our study demonstrates the novel results that the newly isolated strain utilized the DF as a sole carbon source and mineralized it via multiple dioxygenation.

Genetic diversity of Agrobacterium species isolated from nodules of common bean and soybean in Brazil, Mexico, Ecuador and Mozambique, and description of the new species Agrobacterium fabacearum sp. nov.

“…It has also been reported that Agrobacterium strains can carry a symbiotic plasmid (Sym) and form nodules in legumes [5–7]. In addition, several reports of Agrobacterium are about their roles as human pathogens maintaining relationships with nosocomial infections [8], and as a biotechnological tool [9], for example, in programs for obtaining genetically modified plants [10].…”

Aerobic bacterial transformation and biodegradation of dioxins: a review

“…The dioxygenases have a wide range of substrates specificity and belong to the Rieske non-heme iron oxygenases. A few reports have implicated bacteria in the degradation of DF through both dioxygenation pathways Le et al 2014).…”

“…Agrobacterium sp. PH-08 isolated from a saw mill waste dump site also degraded DF through both angular and lateral dioxygenation (Le et al 2014). Growth of the organism was also sustainable on biphenyl but not as efficient as when DF was used as carbon.…”

“…strain p52 (Peng et al 2013), Pseudomonas mendocina strain NSYSU , and Agrobacterium sp. PH-08 (Le et al 2014), Among the listed organisms, Pseudomonas sp. strain CA10 (Sato et al 1997) and strain RW1 (Nam et al 2006) were extensively studied with regards to the genes coding for the dioxin catabolic routes, and also as potential candidates for remediation of contaminated soils.…”

2-Hydroxy-4-(3′-oxo-3′H-benzofuran-2′-yliden)but-2-enoic acid biosynthesis from dibenzofuran using lateral dioxygenation in a Pseudomonas putida strain B6-2 (DSM 28064)

“…Other microorganisms can conduct co-metabolic degradation of DBF via lateral dioxygenation when cultivated with biphenyl (BP) or naphthalene (Becher et al 2000;Kaiya et al 2012;Li et al 2009;Shi et al 2014;Stope et al 2002). A few studies have shown that several bacteria can degrade DBF via both pathways (Jaiswal et al 2011;Le et al 2014;Yamazoe et al 2004). Bacteria using the angular dioxygenation pathway can easily degrade DBF channeled into the tricarboxylic acid (TCA) cycle ; Additional file 1: Figure S1), while bacteria co-metabolizing DBF via lateral (1) 4-Hydroxy-3-methyl-6-phenylbenzofuran-2-carboxylic acid ethyl ester showed selective and potent cytotoxicity against tumors (Hayakawa et al 2004a, b).…”