Investigation into a stress-inducible promoter region from Marinococcus halophilus using green fluorescent protein

A 480-bp Marinococcus halophilus DNA-fragment upstream of the ectoine genes ectABC was linked to the reporter gene gfp(uv) in the stress probe plasmid pBRGFP(uv). On the basis of green fluorescence emitted after application of different types of stress to recombinant Escherichia coli, the DNA sequence was characterized as a stress-responding promoter region. In E. coli, osmotic stress resulted in an increasing fluorescence intensity, whereas the effects of heat or cold were insignificant, suggesting that transcription and/or translation is controlled mainly by an osmotic stress/low-water stress response. Additionally, the stress-counteracting effects of the compatible solutes ectoine and betaine were demonstrated.