Colony morphology and transcriptome profiling of Pseudomonas putida KT2440 and its mutants deficient in alginate or all EPS synthesis under controlled matric potentials
Article first published online: 10 JUN 2014
© 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Volume 3, Issue 4, pages 457–469, August 2014
How to Cite
MicrobiologyOpen 2014; 3(4): 457–469
- Issue published online: 14 AUG 2014
- Article first published online: 10 JUN 2014
- Manuscript Accepted: 5 MAY 2014
- Manuscript Revised: 23 APR 2014
- Manuscript Received: 4 FEB 2014
- Villum Kann Rasmussen Foundation Center of Excellence
- Center for Environmental and Agricultural Microbiology
- environmental stress;
- microbial ecology;
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.