中文摘要：

氮（N）、磷（P）是影响蛋白核小球藻生长的重要因素,通过改变培养液中N、P的浓度,可能实现对蛋白核小球藻富集砷（As）进行调控。为探讨N、P浓度对这种微藻吸收As的影响是否与其生长变化有关,采用室内培养实验,首先研究不同N、P浓度对蛋白核小球藻生长的影响;进而选择不影响小球藻生长的N（247、24.7 mg·L-1）、P（6、0.6 mg·L-1）浓度组合,设置0.8、8 mg·L-1的亚砷酸盐（As3＋）和砷酸盐（As5＋）处理3 d,研究N、P浓度对小球藻As富集和转化的影响。结果表明,当P浓度为6 mg·L-1时,N浓度降低到24.7 mg·L-1不会影响小球藻对As3＋和As5＋的富集及其胞内As形态的转化;而当N浓度为247 mg·L-1时,P浓度降低到0.6 mg·L-1则会显著增加小球藻对As3＋和As5＋的吸收和富集,藻细胞内As5＋还原、甲基化和外排也显著增强。因此,在不影响小球藻细胞生长的条件下,P对其As富集和转化过程的影响比N更为显著。

英文摘要：

Nitrogen（N）and phosphorus（P） are important factors controlling the growth of microalgae such as Chlorella pyrenoidesa. The accumulation of arsenic（As）by this alga may be regulated through adjusting N and P concentrations in the culture. However, it is unclear whether the effects of N and P on the As uptake are related to microalgal growth changes. Therefore, we first studied the impacts of N and P concentrations on the growth of C. pyrenoidesa, and then chosen N（247 mg·L-1, 24.7 mg·L-1）and P（6 mg·L-1, 0.6 mg·L-1）concentrations that had no effects on the algal growth, to investigate their effects on the As metabolism in this algae under exposure of 0.8 mg·L-1and 8mg·L-1As3＋and As5＋. Results showed that the algal As accumulation and transformation were not affected when P was 6 mg·L-1and N was decreased from 247 mg·L-1to 24.7 mg·L-1. However, these processes were significantly impacted when N was 247 mg·L-1and P was decreased from 6 mg·L-1to 0.6 mg·L-1. The decrease in P supply also promoted the reduction, methylation and excretion of As in C.pyrenoidesa. These results indicate that, when N and P have no effects on the algal growth, P influences the As accumulation and transformation greater than N does. This study would provide a theoretical basis for elucidating the regulatory mechanisms of As metabolism and enhancing the efficiency of As pollution remediation in water.