Open AccessIsolation and structure determination of a novel compatible solute from the moderately halophilic purple sulfur bacterium Ectothiorhodospira marismortui
Author(s) -
GALINSKI Erwin A.,
OREN Aharon
Publication year - 1991
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1991.tb16055.x
Subject(s) - halophile , rhodospirillales , betaine , osmolyte , ectoine , biochemistry , osmoregulation , halobacteriaceae , biology , chemistry , osmoprotectant , bacteria , proline , amino acid , halobacterium salinarum , photosynthesis , ecology , genetics , salinity , gene , archaea
The halophilic phototrophic bacterium Ectothiorhodospira marismortui produces three organic osmolytes to counterbalance the osmotic pressure of the surrounding medium: glycine betaine, sucrose, and a novel compound. This new compound, which accounts for approximately 30% of the cells' compatible solutes, was isolated and identified by mass spectrometry and nuclear magnetic resonance. It was characterized as N α ‐carbamoyl‐ l ‐glutamine 1‐amide, an unusual amino acid derivative with no previous reference in the chemical literature. The relatively high cytoplasmic concentration of this compound (∼ 0.5 M) observed at all growth conditions suggests that it may serve a vital function as an osmoticum and/or protectant for Ectothiorhodospira marismortui in a saline environment.