SPECTRA OF THE FORMALDEHYDE-INDUCED ULTRAWEAK LUMINESCENCE FROM YEAST-CELLS

An increase in the intensity and distinct spectral changes of ultrawea k luminescence from the yeast Saccharomyces cerevisiae were measured w hen the metabolism of cells was drastically altered. A small emission peak and a red emission band 680-850 nm appeared when air-dried cells were imbibed in water. Lethal concentrations of HCHO (0.01%-10%) elici ted a 2500 fold increase of the emission intensity and distinct spectr al alterations. A transient 500-580 nm emission appeared in the initia l phase of interaction. Then a gradually increasing long-lasting red e mission band centered around 620 nm predominated in the total spectral range covering 470-850 nm. These emissions were not correlated with m inor changes in fluorescence emission and excitation spectra originati ng from tryptophan, flavins, and unidentified emitters.