PHOTOACOUSTIC SPECTRA AFFECTED BY FUEL-OIL IN THE CHLOROCOCCAL ALGA SCENEDESMUS-ARMATUS

Photoacoustic (PA) spectra of the green chlorococcal alga Scenedesmus armatus grown in batch. cultures with fuel oil have been examined. Concentration-dependent increase in PA-signals in the red chlorophyll and the blue carotenoid regions of the treated algae was observed, irrespective of the culture time. The maxima in the differential PA-spectra after a short-term (3 h) effect of AFOE exhibit a drop of used energy yield absorbed and provided by light-harvesting pigments. These spectra in relation to the long-term cultures additionally prove that quantes of energy transferred to the photosynthetic process are lowered. The PA signal ratios for 684, 484 and 434 nm of algae cultured with/without fuel oil indicate that temporal changes in photoacoustic signals are correlated to the growth rate of the algae exposed. These ratios reached the maxima values in 7th (AFOE) and 9th (10 ppm) day of cultures. The phytotoxicity data (the growth of population, chlorophyll a and dry matter content of cells) and PA spectra of algae cultured with AFOE are discussed.