硒浓度对紫球藻的有机硒转化能力及生长的影响

Effects of selenium concentrationson organic selenium transformation capacity and growth of Porphyridium cruentum

目的探究不同外加硒质量浓度对紫球藻有机硒转化能力、生长及抗氧化酶活性的影响。方法通过一次添加亚硒酸钠使硒终质量浓度分别达到0.2、0.5、1.0、2.0、5.0 mg/L,以不添加硒的紫球藻为对照组,对紫球藻生长指标和抗氧化酶活性进行分析,并采用氢化物原子荧光光谱法(hydride generation atomic fluorescence spectrometry,HG-AFS)检测紫球藻藻体中总硒以及无机硒含量。结果0.2、0.5 mg/L质量浓度的硒对紫球藻生长具有促进作用,1.0、2.0、5.0 mg/L质量浓度的硒则抑制了紫球藻生长;0~5.0 mg/L硒质量浓度浓度范围内,紫球藻硒含量与所加硒质量浓度成正比,其中5.0 mg/L硒质量浓度下,紫球藻有机硒含量达484.47μg/g,占总硒含量的93.71%;硒能诱导紫球藻细胞谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)和超氧化物歧化酶(superoxide dismutase,SOD)活性增加,且在高硒质量浓度下,两种酶活性会再次增强。结论低质量浓度硒有利于紫球藻生长,高质量浓度硒则抑制其生长,紫球藻GSH-Px与SOD酶活性表现相似,且紫球藻对硒的富集和转化能力较强。

Objective To investigate the effects of different added selenium concentrations on the organic selenium conversion capacity,the growth and antioxidant enzyme activity of Porphyridium cruentum.Methods The growth index and antioxidant enzyme activity of Porphyridium cruentum were analyzed by adding sodium selenite once to reach the final selenium mass concentration of 0.2,0.5,1.0,2.0 and 5.0 mg/L,respectively,using Porphyridium cruentum without selenium as the control group,and the content of total and inorganic selenium in Porphyridium cruentum algae was determined by hydride generation atomic fluorescence spectrometry(HG-AFS).Results The growth of Porphyridium cruentum was promoted by 0.2,0.5 mg/L selenium,while 1.0,2.0,5.0 mg/L selenium inhibited the growth of Porphyridium cruentum.The selenium content of Porphyridium cruentum was proportional to the added selenium concentration in the range of 0-5.0 mg/L selenium concentrations,and when the concentration of selenium was 5.0 mg/L,the content of organic selenium reached 484.47μg/g,accounting for 93.71%of the total selenium content.Glutathione peroxidase(GSH-Px)and super oxide dismutase(SOD)activities of Porphyridium cruentum could be increased by selenium induction,and both enzyme activities were enhanced again at high selenium concentration.Conclusion Low concentration of selenium led to promote the growth of Porphyridium cruentum,while high concentration of selenium inhibits its growth,GSH-Px and SOD enzymes of Porphyridium cruentum show similar activities,and Porphyridium cruentum has a high capacity for enrichment and transformation of selenium.