In vivo kinetics of lipids and astaxanthin evolution in Haematococcus pluvialis mutant under 15% CO2 using Raman microspectroscopy

In vivo spatiotemporal dynamics of lipids and astaxanthin evolution in Haematococcus pluvialis mutant induced with 15% CO2 and high light intensity were monitored with high spatial resolution in a nondestructive and label-free manner using single-cell Raman imaging. Astaxanthin intensity increased by 3.5 times within 12 h under 15% CO2, and the accumulation rate was 5.8 times higher than that under air. Lipids intensity under 15% CO2 was 27% higher than that under air. The lipids initially concentrated in chloroplast under 15% CO2 due to an increase of directly photosynthetic fatty acid, which was different from the whole-cell dispersed lipids under air. Astaxanthin produced in chloroplast first accumulated around nucleus and then spread in cytoplasmic lipids under both air and 15% CO2. The calculation results of kinetic models for lipids and astaxanthin evolutions showed that accumulation rate of lipids was much higher than that of astaxanthin in cells. (C) 2017 Elsevier Ltd. All rights reserved.