Comparison of Different Cells of Haematococcus pluvialis Reveals an Extensive Acclimation Mechanism during its Aging Process: From a Perspective of Photosynthesis

Abstract

Both biomass dominated green vegetative cells (GV) and astaxanthin-dominated orange resting cells (OR) affect the final astaxanthin yield in industry. Examination of Haematococcus pluvialis revealed that the OR cells greatly varied from the GV cells at both cellular and subcellular levels. In particular, the thylakoid membranes in the OR were disassembled and fragmented. Furthermore, the OR conserved most of the photosynthetic pigments, with elevated concentrations of violaxanthin, antheraxanthin, and neoxanthin. Notably, moderate photosynthesis was detected in OR, even though most of the thylakoid membranes were disassembled, when compared with those in the GV. However, the energy distribution pattern between photosystem I and II (PSI and PSII) in the OR favored PSI, which was also confirmed by 77-K fluorescence. As zeaxanthin was not detected in the OR, we attribute the acclimation role to astaxanthin, instead of xanthophyll cycle. Additionally, proteomic-scale comparison analysis of thylakoids of the OR and GV indicated no photosynthetically remarkable variations. However, an extensive acclimation mechanism of H. pluvialis was proposed, in which proteins in thylakoid of GV were noted to be involved in biomass accumulation and those in OR were involved in stress response. Conclusions of the comparative analysis might provide some physiological background of OR for astaxanthin production by using H. pluvialis.

Cellular Capacities for High-Light Acclimation and Changing Lipid Profiles across Life Cycle Stages of the Green Alga Haematococcus pluvialis

“…PSI cyclic electron transport may have multiple functions in photoprotection, such as dissipating energy absorbed at PSI and maintaining a ΔpH for NPQ to down-regulate energy production at PSII [26]. H. pluvialis cells changed the energy balance between PSII and PSI under HL by enhancing the quantum yield of PSI [Y(I)] while reducing Y(II) [15].We speculate that increasing the PSI/PSII ratio, decoupling PSI and PSII by decreasing cytochrome b 6 f during encystment, and increasing cyclic electron transport around PSI are a suite of photoprotective mechanisms developed in palmella cells for acclimation under HL.…”

Silicon enhances the growth of Phaeodactylum tricornutum Bohlin under green light and low temperature

“…Assessment of photosynthesis was carried out as described48 with minor modification using a chlorophyll fluorometer Dual-PAM-100 (Heinz Walz GmbH, Germany). Briefly,samples of normal cultured cells and silicon starved cells were dark-adapted for 15 min before the measurement.…”

Commercial astaxanthin production derived by green alga Haematococcus pluvialis : A microalgae process model and a techno-economic assessment all through production line

“…20 μm) as well as the calculated concentration of suspended solids in the 'red stage' (i.e. 0.035%, see Section 4.2) 1 in association with the high TSS concentration of disk-stack centrifugation (15% combined with gravity sedimentation), this method is ideal for an astaxanthin production line [37,42,65,94,109]. Implementing disk-stack centrifugation at 13,000 g, a biomass recovery efficiency that exceeds 95% can be achieved [40].…”