Pigment composition and adaptation in free-living and symbiotic strains of Acaryochloris marina

Acaryochloris marina strains have been isolated from several varied locations and habitats worldwide, thus demonstrating a diverse and dynamic ecology. In this study, the whole cell photophysiologies of strain MBIC11017, originally isolated from a colonial ascidian, and the free-living epilithic strain CCMEE5410 are analysed by absorbance and fluorescence spectroscopy, laser scanning confocal microscopy, SDS-PAGE and subsequent protein analysis. We demonstrate pigment adaptation in MBIC11017 and CCMEE5410 under different light regimes. We show that strain MBIC11017 loses its phycobilins relative to its chlorophyll d content when grown at light intensities of 40 μE m-2 s-1 without shaking and 100 μE m-2 s-1 with shaking. Our results indicate the greater the light intensity both strains MBIC11017 and CCMEE5410 are grown at, the greater the decrease in their chlorophyll d content. We also conclude that phycobiliproteins are absent in the free-living strain CCMEE5410.