Cells of Haematococcus pluvialis Flot. et Will were collected in four different growth phases. We quantified the initial and total enzyme activity of ribulose-1,5-bisphosphate carboxylase （Rubiseo） in crude extracts...Cells of Haematococcus pluvialis Flot. et Will were collected in four different growth phases. We quantified the initial and total enzyme activity of ribulose-1,5-bisphosphate carboxylase （Rubiseo） in crude extracts, and the relative expression of large-subunit ribulose-1,5-bisphosphate caboxylase / oxygenase （rbcL） mRNA. We measured the ratio of photosynthetic rate to respiration rate （P/R）, maximal effective quantum yield of photosystem II （Fv/Fm）, electron transport rate （ETR）, actual photochemical efficiency of PSI1 in the light （ФPSII）, and non-photochemical quenching （NPQ）. Green vegetative cells were found to be in the most active state, with a relatively higher P/R ratio. These cells also displayed the lowest NPQ and the highest Fv/Fm, ETR, and ФPSII, indicating the most effective PSII. However, both Rubisco activity and rbcL mRNA expression were the lowest measured. In orange resting cysts with relatively lower P/R and NPQ, Rubisco activity and rbcL expression reached a peak, while Fv/Fm, ETR, and ФPSII were the lowest measured. Taking into account the methods of astaxanthin induction used in industry, we suggest that Rubisco may participate in astaxanthin accumulation in H. pluvialis. A continuous and sufficient supply of a carbon source such as CO2 may therefore aid the large scale production of astaxanthin.展开更多
基金Supported by the National Basic Projects for Science and Technology(No. SQ2012FY4910019-1)the Project of Science and Technology for Supporting Tianjin Development (No. 10ZCKFSH0070)the Project for Developing Marine Economy by Science and Technology in Tianjin(KX2010-0005)
文摘Cells of Haematococcus pluvialis Flot. et Will were collected in four different growth phases. We quantified the initial and total enzyme activity of ribulose-1,5-bisphosphate carboxylase （Rubiseo） in crude extracts, and the relative expression of large-subunit ribulose-1,5-bisphosphate caboxylase / oxygenase （rbcL） mRNA. We measured the ratio of photosynthetic rate to respiration rate （P/R）, maximal effective quantum yield of photosystem II （Fv/Fm）, electron transport rate （ETR）, actual photochemical efficiency of PSI1 in the light （ФPSII）, and non-photochemical quenching （NPQ）. Green vegetative cells were found to be in the most active state, with a relatively higher P/R ratio. These cells also displayed the lowest NPQ and the highest Fv/Fm, ETR, and ФPSII, indicating the most effective PSII. However, both Rubisco activity and rbcL mRNA expression were the lowest measured. In orange resting cysts with relatively lower P/R and NPQ, Rubisco activity and rbcL expression reached a peak, while Fv/Fm, ETR, and ФPSII were the lowest measured. Taking into account the methods of astaxanthin induction used in industry, we suggest that Rubisco may participate in astaxanthin accumulation in H. pluvialis. A continuous and sufficient supply of a carbon source such as CO2 may therefore aid the large scale production of astaxanthin.
