Comparison of different cells of Haematococcus pluvialis reveals an extensive acclimation mechanism during its aging process: from a perspective of photosynthesis.
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.
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
Wenhui
W
Gu
Xiujun
X
Xie
Shan
S
Gao
Wei
W
Zhou
Guanghua
G
Pan
Guangce
G
Wang
D000064:Acclimatization; D020418:Algal Proteins / Q000737:chemistry; D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000378:metabolism; D000460:Chlorophyta / Q000166:cytology* / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D010788:Photosynthesis / Q000502:physiology*; D012995:Solubility; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013347:Subcellular Fractions / Q000378:metabolism; D013696:Temperature; D020524:Thylakoids / Q000378:metabolism / Q000648:ultrastructure
D020418:Algal Proteins; D002734:Chlorophyll