title: Expanding small-molecule functional metagenomics through parallel screening of broad-host-range cosmid environmental DNA libraries in diverse proteobacteria.
abstract: The small-molecule biosynthetic diversity encoded within the genomes of uncultured bacteria is an attractive target for the discovery of natural products using functional metagenomics. Phenotypes commonly associated with the production of small molecules, such as antibiosis, altered pigmentation, or altered colony morphology, are easily identified from screens of arrayed metagenomic library clones. However, functional metagenomic screening methods are limited by their intrinsic dependence on a heterologous expression host. Toward the goal of increasing the small-molecule biosynthetic diversity found in functional metagenomic studies, we report the phenotypic screening of broad-host-range environmental DNA libraries in six different proteobacteria: Agrobacterium tumefaciens, Burkholderia graminis, Caulobacter vibrioides, Escherichia coli, Pseudomonas putida, and Ralstonia metallidurans. Clone-specific small molecules found in culture broth extracts from pigmented and antibacterially active clones, as well as the genetic elements responsible for the biosynthesis of these metabolites, are described. The host strains used in this investigation provided access to unique sets of clones showing minimal overlap, thus demonstrating the potential advantage conferred on functional metagenomics through the use of multiple diverse host species.
authors.affiliation: Howard Hughes Medical Institute, Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, USA.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Craig
authors.forename: Fang-Yuan
authors.initials: FY
authors.lastname: Chang
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Kim
authors.forename: Steven C
authors.initials: SC
authors.lastname: Obiajulu
authors.forename: Sean F
authors.initials: SF
authors.lastname: Brady
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics*; D003360:Cosmids; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004783:Environmental Microbiology; D015723:Gene Library; D014644:Genetic Variation; D055432:Metabolomics / Q000379:methods*; D056186:Metagenomics / Q000379:methods*; D008969:Molecular Sequence Data; D020560:Proteobacteria / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial