Fig. 1

Phycobilisome excitation energy transfer in L. glaciale. A A typical absorbance spectrum from L. glaciale, obtained from measured reflectivity. B Representative time-resolved fluorescence spectra of L. glaciale after excitation with 200 fs light pulses at 515 nm across time windows up to 500 ps. C Fluorescence kinetics of chromophore phycoerythrobilin (PEB), phycocyanobilin (PCB) and photosysystems II and I. D The compartmental model of consecutive energy transfer (A → B → C) applied to fit the time-resolved fluorescence spectra with time constants and spectral amplitudes of each compartment obtained from fitting. The down-pointing arrows from A and B compartments represent the natural decay of excitons in phycoerythrin (PE) and phycocyanin (PC) hexamers with a time constant of 1 ns which is taken from the fluorescence decay of PE in water (cf. Additional File 1: Figure S2), whilst the 220 ps decay time of the C compartment is obtained from fitting and represents charge separation in photosystems