Archives of Microbiology

, 184:56

Role of trehalose synthesis pathways in salt tolerance mechanism of Rhodobacter sphaeroides f. sp. denitrificans IL106

Authors

  • Fumihiro Makihara
    • Department of Applied Biological Chemistry, Graduate School of Agriculture and Life SciencesThe University of Tokyo
    • Department of Applied Biological Chemistry, Graduate School of Agriculture and Life SciencesThe University of Tokyo
  • Kiichi Sato
    • Department of Applied Biological Chemistry, Graduate School of Agriculture and Life SciencesThe University of Tokyo
  • Shinji Masuda
    • Graduate School of Bioscience and BiotechnologyTokyo Institute of Technology
  • Kenji V. P. Nagashima
    • Despartment of BiologyTokyo Metropolitan University
  • Mitsuru Abo
    • Department of Applied Biological Chemistry, Graduate School of Agriculture and Life SciencesThe University of Tokyo
  • Akira Okubo
    • Department of Applied Biological Chemistry, Graduate School of Agriculture and Life SciencesThe University of Tokyo
Original Paper

DOI: 10.1007/s00203-005-0012-5

Cite this article as:
Makihara, F., Tsuzuki, M., Sato, K. et al. Arch Microbiol (2005) 184: 56. doi:10.1007/s00203-005-0012-5

Abstract

The photosynthetic bacterium Rhodobacter sphaeroides (R. sphaeroides) f. sp. denitrificans IL106 accumulates trehalose as the major organic osmoprotectant in response to a salt stress. An analysis of the R. sphaeroides 2.4.1 genome sequence revealed the presence of five different genes encoding enzymes belonging to three putative trehalose biosynthesis pathways (OtsA-OtsB, TreY-TreZ, and TreS). The function of the different pathways of trehalose was studied by characterizing strains defective in individual trehalose biosynthetic routes. A phenotypic comparison revealed that trehalose synthesis in R. sphaeroides f. sp. denitrificans IL106 is mediated mainly by the OtsA-OtsB pathway and, to some extent, by the TreY-TreZ pathway. Strains with the simultaneous inactivation of these two pathways were completely unable to synthesize trehalose. On the other hand, treS mutants showed an increase in the trehalose level. These results suggest that treS plays a role in trehalose degradation. In addition, treS was found to be important in reducing trehalose after osmotic stress was removed. In this report, we show that the strains that accumulate the most trehalose adapt to salt stress earlier. This is the first report of an organism using multiple pathways to synthesize trehalose solely for use as a compatible solute against salt stress.

Keywords

Rhodobacter sphaeroidesTrehaloseSalt stress

Copyright information

© Springer-Verlag 2005