盐度对蛋白核小球藻生长、叶绿素荧光参数及代谢酶的影响

Effect of Salinity on the Growth,Chlorophyll Fluorescence Characteristics and Enzymes of Chlorella pyrenoidosa

以蛋白核小球藻820为实验材料,研究了3种盐度(15、30、45)对其生长、叶绿素荧光参数和两种代谢酶活性的影响,以了解该小球藻对盐度的适应能力.结果表明,蛋白核小球藻820的生长随盐度增加而变慢;而油脂含量随盐度增加而升高.叶绿素荧光参数中的PSII最大光能转化效率(Fv/Fm)、PSII实际光能转化效率(ΦPSII)、光化学淬灭系数(qP)随盐度升高下降,而非光化学淬灭系数(NPQ)随盐度升高而上升.超氧化物歧化酶(SOD)活性变化大致趋势是低盐和高盐下活性较高,碳酸酐酶(CA)活性则随盐度升高而降低,第5d时45盐度是30盐度培养的0.43倍.因此,认为高盐一定程度地抑制了蛋白核小球藻的生长、叶绿素荧光参数和CA活性,但是促进了总脂含量和抗氧化酶SOD活性的提高.

Chlorella pyrenoidosa is a kind of important economic microalgae.In this paper,the effects of different salinity（15,30 and 45） on the growth,total lipid content,chlorophyll fluorescence parameters and enzymic activities of C.pyrenoidosa 820 are investigated in order to understand how the alga responds to salinity.Results show that,with the increase of salinity,the growth speed of C.pyrenoidosa 820 decreases,but the lipid contents keep increasing.The chlorophyll fluorescence parameters of the maximal photochemical efficiency of PSII（Fv/Fm）,actual photochemical efficiency of PSII（ΦPSII） and photochemical quenching（qP） declinee with the increasing salinity,whereas the non-photochemical quenching（NPQ） is enhanced with the increasing salinity.The superoxide dismutase（SOD） activities are higher under the 15 and 45 salinity than that of 30.The carbonic anhydrase（CA） activities are reversely propotional to the salinity increase,and CA activity of 45 is 43% of that of 30 salinity on the fifth day.These results suggest that the growth,chlorophyll fluorescence parameters and CA activity of C.pyrenoidosa are inhibited to a certain extent by the increased salinity,but the lipid content and SOD activity are enhanced to adapt the adverse salt environment.