The Impact of Sodium Selenite on the Growth, Antioxidant Enzyme Activity and Selenium Content of <i>Nannochloropsis oceanica</i>

为探究不同质量浓度的亚硒酸钠对微拟球藻(Nannochloropsis oceanica)生长、抗氧化酶活性及硒含量的影响，试验设计0 (对照)、3、6、12、24 mg/L共5个处理组，分别为A、B、C、D和E组，每组设3个平行，定期检测各组微拟球藻的藻细胞密度、相对生长速率、抗氧化酶活性(过氧化氢酶CAT、谷胱甘肽过氧化物酶GSH-Px和超氧化物歧化酶SOD)及硒含量的变化，藻初始接种密度为5 × 106 cells/mL。试验结果表明：C组从第3天开始藻细胞密度显著高于其他组(P P P > 0.05)；从培养第3天至结束，C组微拟球藻细胞密度显著高于对照组和其他浓度组(P P P P To investigate the effects of different concentrations of sodium selenite on the growth, antioxidant enzyme activities, and selenium content of Nannochloropsis oceanica, the experiment was designed with five treatment groups: 0 (A, control), 3 (B), 6 (C), 12 (D), and 24 mg/L (E), each with three replicates. The cell density, relative growth rate, antioxidant enzyme activities (catalase, CAT; glutathione peroxidase, GSH-Px; and (superoxide dismutase, SOD), and selenium content of N. oceanica were measured periodically. The results showed that when the initial inoculation cell density of N. oceanica was 5 × 106 cells/mL, from the third day of cultivation until the end, the cell density in the group C was significantly higher than that in the other groups (P P N. oceanica in the group C was significantly higher than that in the groups A, D, and E (P N. oceanica (P N. oceanica increased with the increasing concentration of sodium selenite, but the selenium accumulation capacity decreased when the concentration was too high. The study indicates that adding a low concentration of sodium selenite can promote the growth and antioxidant enzyme activities of N. oceanica and effectively enhance selenium accumulation. Under the experimental conditions, the optimal concentration of sodium selenite for N. oceanica cultivation was found to be 6 mg/L.