title: Colony morphology and transcriptome profiling of Pseudomonas putida KT2440 and its mutants deficient in alginate or all EPS synthesis under controlled matric potentials.
abstract: Pseudomonas putida is a versatile bacterial species adapted to soil and its fluctuations. Like many other species living in soil, P. putida often faces water limitation. Alginate, an exopolysaccharide (EPS) produced by P. putida, is known to create hydrated environments and alleviate the effect of water limitation. In addition to alginate, P. putida is capable of producing cellulose (bcs), putida exopolysaccharide a (pea), and putida exopolysaccharide b (peb). However, unlike alginate, not much is known about their roles under water limitation. Hence, in this study we examined the role of different EPS components under mild water limitation. To create environmentally realistic water limited conditions as observed in soil, we used the Pressurized Porous Surface Model. Our main hypothesis was that under water limitation and in the absence of alginate other exopolysaccharides would be more active to maintain homeostasis. To test our hypothesis, we investigated colony morphologies and whole genome transcriptomes of P. putida KT2440 wild type and its mutants deficient in synthesis of either alginate or all known EPS. Overall our results support that alginate is an important exopolysaccharide under water limitation and in the absence of alginate other tolerance mechanisms are activated.
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Building 113, Kongens Lyngby, Denmark.
authors.forename: Gamze
authors.initials: G
authors.lastname: Gulez
authors.forename: Ali
authors.initials: A
authors.lastname: Altıntaş
authors.forename: Mustafa
authors.initials: M
authors.lastname: Fazli
authors.forename: Arnaud
authors.initials: A
authors.lastname: Dechesne
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Workman
authors.forename: Tim
authors.initials: T
authors.lastname: Tolker-Nielsen
authors.forename: Barth F
authors.initials: BF
authors.lastname: Smets
mesh_terms: D000464:Alginates / Q000378:metabolism*; D003681:Dehydration; D020869:Gene Expression Profiling; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D016958:Pseudomonas putida / Q000235:genetics* / Q000378:metabolism*; D013312:Stress, Physiological; D014867:Water / Q000378:metabolism
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D011135:Polysaccharides, Bacterial; D014867:Water; D020723:Glucuronic Acid
keywords: Bioinformatics; Pseudomonas; environmental stress; microbial ecology