Research Information System University of Greifswald

Schroeter R*, Hoffmann T, Voigt B, Meyer H, Bleisteiner M, Muntel J, Jürgen B, Albrecht D¹, Becher D², Lalk M³, Evers S, Bongaerts J, Maurer K, Putzer H, Hecker M, Schweder T⁴, Bremer E

1 - Institut für Mikrobiologie / Abteilung Mikrobielle Physiologie und Molekularbiologie

2 - Institut für Mikrobiologie / Abteilung Mikrobielle Proteomics

3 - Institut für Biochemie / AG Stoffwechselbiochemie / Metabolomics

4 - Institut für Pharmazie / AG Pharmazeutische Biotechnologie

The Gram-positive endospore-forming bacterium Bacillus licheniformis can be found widely in nature and it is exploited in industrial processes for the manufacturing of antibiotics, specialty chemicals, and enzymes. Both in its varied natural habitats and in industrial settings, B. licheniformis cells will be exposed to increases in the external osmolarity, conditions that trigger water efflux, impair turgor, cause the cessation of growth, and negatively affect the productivity of cell factories in biotechnological processes. We have taken here both systems-wide and targeted physiological approaches to unravel the core of the osmostress responses of B. licheniformis. Cells were suddenly subjected to an osmotic upshift of considerable magnitude (with 1 M NaCl), and their transcriptional profile was then recorded in a time-resolved fashion on a genome-wide scale. A bioinformatics cluster analysis was used to group the osmotically up-regulated genes into categories that are functionally associated with the synthesis and import of osmostress-relieving compounds (compatible solutes), the SigB-controlled general stress response, and genes whose functional annotation suggests that salt stress triggers secondary oxidative stress responses in B. licheniformis. The data set focusing on the transcriptional profile of B. licheniformis was enriched by proteomics aimed at identifying those proteins that were accumulated by the cells through increased biosynthesis in response to osmotic stress. Furthermore, these global approaches were augmented by a set of experiments that addressed the synthesis of the compatible solutes proline and glycine betaine and assessed the growth-enhancing effects of various osmoprotectants. Combined, our data provide a blueprint of the cellular adjustment processes of B. licheniformis to both sudden and sustained osmotic stress.

PloS one;Schroeter, Rebecca Hoffmann, Tamara Voigt, Birgit Meyer, Hanna Bleisteiner, Monika Muntel, Jan Jurgen, Britta Albrecht, Dirk Becher, Dorte Lalk, Michael Evers, Stefan Bongaerts, Johannes Maurer, Karl-Heinz Putzer, Harald Hecker, Michael Schweder, Thomas Bremer, Erhard Research Support, Non-U.S. Gov't United States PLoS One. 2013 Nov 15;8(11):e80956. doi: 10.1371/journal.pone.0080956. eCollection 2013.