title: Metabolomic characterization of the salt stress response in Streptomyces coelicolor.
abstract: The humicolous actinomycete Streptomyces coelicolor routinely adapts to a wide variety of habitats and rapidly changing environments. Upon salt stress, the organism is also known to increase the levels of various compatible solutes. Here we report the results of the first high-resolution metabolomics time series analysis of various strains of S. coelicolor exposed to salt stress: the wild type, mutants with progressive knockouts of the ectoine biosynthesis pathway, and two stress regulator mutants (with disruptions of the sigB and osaB genes). Samples were taken from cultures at 0, 4, 8, and 24 h after salt stress treatment and analyzed by liquid chromatography-mass spectrometry with an LTQ Orbitrap XL mass spectrometer. The results suggest that a large fraction of amino acids is upregulated in response to the salt stress, as are proline/glycine-containing di- and tripeptides. Additionally we found that 5'-methylthioadenosine, a known inhibitor of polyamine biosynthesis, is downregulated upon salt stress. Strikingly, no major differences between the wild-type cultures and the two stress regulator mutants were found, indicating a considerable robustness of the metabolomic response to salt stress, compared to the more volatile changes in transcript abundance reported earlier.
authors.affiliation: Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, Netherlands.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kol
authors.forename: M Elena
authors.initials: ME
authors.lastname: Merlo
authors.forename: Richard A
authors.initials: RA
authors.lastname: Scheltema
authors.forename: Marcel
authors.initials: M
authors.lastname: de Vries
authors.forename: Roel J
authors.initials: RJ
authors.lastname: Vonk
authors.forename: Niels A
authors.initials: NA
authors.lastname: Kikkert
authors.forename: Lubbert
authors.initials: L
authors.lastname: Dijkhuizen
authors.forename: Rainer
authors.initials: R
authors.lastname: Breitling
authors.forename: Eriko
authors.initials: E
authors.lastname: Takano
mesh_terms: D000192:Actinomycetales; D000599:Amino Acids, Diamino / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000235:genetics; D053898:Biosynthetic Pathways / Q000235:genetics; D002853:Chromatography, Liquid; D055786:Gene Knockout Techniques; D013058:Mass Spectrometry; D055442:Metabolome; D055432:Metabolomics; D009997:Osmotic Pressure; D012492:Salts / Q000633:toxicity*; D048372:Streptomyces coelicolor / Q000502:physiology*; D013312:Stress, Physiological
chemical_list: D000599:Amino Acids, Diamino; D001426:Bacterial Proteins; D012492:Salts; C045628:ectoine