ABSTRACT: Genome sequencing of a gamma-hexachlorocyclohexane (g-HCH)-degrading bacterium Sphingobium japonicum strain L15T isolated from an experimental field soil contaminated with g-HCH.
Project description:The project aims to to understand the response of the lin genes in Sphingobium indicum B90A under the stress of HCH isomers and the metabolites formed during degradation of hexachlorocyclohexane (HCH). Entire cell proteome from Sphingobium indicum B90A was extracted in presence of four HCH isomers. Quantitative proteomics confirmed the constitutive expression of the linA, linB and linC genes of the HCH degradation pathway crucial for the initiation of HCH isomers degradation. LinM and LinN were upregulated in the presence of β- and δ-isomers suggested the important role of ABC transporter system in the depletion of β- and δ-HCH. Besides this HCH isomers induced oxidative stress caused systemic changes in strain B90A proteome.
Project description:Biotransformation of soil organochlorine pesticides (OCP) is often impeded by a lack of nutrients relevant for bacterial growth and/or co-metabolic OCP biotransformation. By providing space-filling mycelia, fungi promote contaminant biodegradation by facilitating bacterial dispersal and the mobilization and release of nutrients in the mycosphere. We here tested whether mycelial nutrient transfer from nutrient-rich to nutrient-deprived areas facilitates bacterial OCP degradation in a nutrient-deficient habitat. The legacy pesticide hexachlorocyclohexane (HCH), a non-HCH-degrading fungus (Fusarium equiseti K3), and a co-metabolically HCH-degrading bacterium (Sphingobium sp. S8) isolated from the same HCH-contaminated soil were used in spatially structured model ecosystems. Using 13C-labelled fungal biomass and protein-based stable isotope probing (protein-SIP), we traced the incorporation of 13C fungal metabolites into bacterial proteins while simultaneously determining the biotransformation of the HCH isomers. The relative isotope abundance (RIA, 7.1 – 14.2%), labeling ratio (LR, 0.13 – 0.35), and the shape of isotopic mass distribution profiles of bacterial peptides indicated the transfer of 13C-labeled fungal metabolites into bacterial proteins. Distinct 13C incorporation into the haloalkane dehalogenase (linB) and 2,5-dichloro-2,5-cyclohexadiene-1,4-diol dehydrogenase (LinC), as key enzymes in metabolic HCH degradation, underpin the role of mycelial nutrient transport and fungal-bacterial interactions for co-metabolic bacterial HCH degradation in heterogeneous habitats. Nutrient uptake from mycelia increased HCH removal by twofold as compared to bacterial monocultures. Fungal-bacterial interactions hence may play an important role in the co-metabolic biotransformation of OCP or recalcitrant micropollutants (MPs).
Project description:Comparison of hexachlorocyclohexane (HCH) contaminated soils from Spain with a community-specific microarray. These results are being submitted for publication and represent the first use of microarrays for analysis of soil DNA and the first community-specific microarray design. Keywords: other
Project description:Comparison of hexachlorocyclohexane (HCH) contaminated soils from Spain with a community-specific microarray. These results are being submitted for publication and represent the first use of microarrays for analysis of soil DNA and the first community-specific microarray design. Keywords: other
Project description:Draft Genome Sequences of Sphingobium species associated with Hexachlorocyclohexane (HCH) degradation isolated from HCH contaminated soil
