Fluorescence of chlorophyll in brown algae and diatoms

摘要

At−196°C, brown algae and a diatom showed two emission bands of fluorescence at 690–695 nm and 705–715 nm. This is in contrast to the occurrence of three low temperature emission bands in green, blue-green and red algae, and in chloroplasts of higher plants. Further, the position of the long-wavelength emission band in brown algae and the diatom lies about 15 nm on the shorter wavelengths side than those for other classes of algae and for chloroplasts of higher plantsThe form of chlorophyllawhich emits long-wavelength bands is unstable and is easily destroyed by mechanical treatment of the tissue or cells of brown algae and diatomsAction spectra of fluorescence showed that 530–560 nm-light, absorbed by fucoxanthin, contributed to the emissions at 690–695 nm and 705–715 nm at−196°C. Light absorbed by chlorophyllcalso contributed to both emissions, but was less effective for the long-wavelength band at 705–715 nmThe time course of fluorescence for the long-wavelength emission band at−196°C showed the same pattern as those for other algae and chloropl