title: Glutamate transport and xanthan gum production in the plant pathogen Xanthomonas axonopodis pv. citri.
abstract: L-glutamate plays a central role in nitrogen metabolism in all living organisms. In the genus Xanthomonas, the nitrogen nutrition is an important factor involved in the xanthan gum production, an important exopolysaccharide with various industrial and biotechnological applications. In this report, we demonstrate that the use of L-glutamate by the phytopathogen Xanthomonas axonopodis pv. citri as a nitrogen source in defined medium significantly increases the production of xanthan gum. This increase is dependent on the L-glutamate concentration. In addition, we have also characterized a glutamate transport system that is dependent on a proton gradient and on ATP and is modulated by amino acids that are structurally related to glutamate. This is the first biochemical characterization of an energy substrate transport system observed in a bacterial phytopathogen with a broad economic and industrial impact due to xanthan gum production.
authors.affiliation: Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, Avenida Lineu Prestes 1374, Cidade Universitária, São Paulo, 05508-900, Brazil, robert.rojas@medkem.gu.se.
authors.forename: Robert
authors.initials: R
authors.lastname: Rojas
authors.forename: Sabrina
authors.initials: S
authors.lastname: Nishidomi
authors.forename: Roberto
authors.initials: R
authors.lastname: Nepomuceno
authors.forename: Elisa
authors.initials: E
authors.lastname: Oshiro
authors.forename: Rita
authors.initials: R
authors.lastname: de Cassia Café Ferreira
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D027322:Amino Acid Transport System X-AG / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D011392:Proline / Q000378:metabolism; D011522:Protons; D013379:Substrate Specificity; D053532:Xanthomonas axonopodis / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D027322:Amino Acid Transport System X-AG; D001426:Bacterial Proteins; D011135:Polysaccharides, Bacterial; D011522:Protons; D018698:Glutamic Acid; D000255:Adenosine Triphosphate; D011392:Proline; D009584:Nitrogen; C002563:xanthan gum