Absorption, Steady-State Fluorescence and Solvent Effect Studies of Fluorescent Haloarchaeal Bacterioruberin

Fluorescence characterization of halophilic archaeal C50 carotenoid-bacterioruberin extracts was investigated using UV/Vis and steady-state fluorescence spectrophotometry in solvents with different polarity. Different extracts showed maximum absorption and fluorescence wavelengths between 369-536 nm and 540-569 nm. Stokes' shifts varied between 50-79 nm depending on the solvent. In particular, water extract showed significant Stokes' shifts with the increase in polarity index; however, fluorescence wavelength (band position) and shape were found to be independent of polarity. According to the obtained results, it is thought that bacterioruberin will be a new alternative material with increasing applications in optics, biosensor/chemosensor, biotechnology, analytical chemistry and nanotechnology due to its fluorescence properties.