| Content Provider |
World Health Organization (WHO)-Global Index Medicus |
| Author |
Wang, Ning-Xin Huang, Bin Xu, Shen Wei, Zhong-Bo Miao, Ai-Jun Ji, Rong Yang, Liu-Yan |
| Description |
Country affiliation: China Author Affiliation: Wang NX ( State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu Province, China.); Huang B ( State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu Province, China.); Xu S ( State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu Province, China.); Wei ZB ( State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu Province, China.); Miao AJ ( State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu Province, China. Electronic address: miaoaj@nju.edu.cn.); Ji R ( State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu Province, China. Electronic address: ji@nju.edu.cn.); Yang LY ( State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu Province, China.) |
| Abstract |
We studied arsenite (iAs(III)) accumulation, oxidation, and toxicity in the freshwater green alga Chlamydomonas reinhardtii under nutrient-enriched (+NP), phosphorus-limited (-P), and nitrogen-limited (-N) conditions. The -P alga (55.1 µM) had a Michaelis constant (Kd) for uptake approximately one tenth of the +NP (419 µM) and -N (501 µM) cells, indicating iAs(III) uptake inhibition by extracellular phosphate. This conclusion was supported by the hyperbolic reduction in iAs(III) uptake rate (V) from 9.2 to 0.8 µmol/g-dw/h when the extracellular phosphate concentration went up from 0 to 250 µM. The maximal iAs(III) uptake rate (Vmax) of the -N alga (24.3 µmol/g-dw/h) was twice as much as that of the +NP (12 µmol/g-dw/h) and -P (8.1 µmol/g-dw/h) cells. It implies that more arsenic transporters were synthesized under the -N condition. Once accumulated, iAs(III) was oxidized and a higher proportion of arsenate (iAs(V)) was observed at lower [As]dis or under nutrient-limited conditions. Nevertheless, iAs(III) oxidation mainly occurred outside the cells with the extent of oxidation reciprocal to [As]dis. Based on the logistic modeling of the concentration-response curves in the +NP, -P, and -N toxicity tests, iAs(III) had an [As]dis-based EC50 of 1763, 13.1, and 1208 µM and an intracellular arsenic concentration based EC50 of 35.6, 28.8, and 195 µmol/g-dw, respectively. Higher iAs(III) toxicity to the -P cells occured because of their increased iAs(III) accumulation, whereas the underlying mechanisms why the -N alga was more tolerant need to be further revealed. Overall, both N and P had remarkable effects on the behavior and effects of iAs(III), which cannot be disregarded in the biogeochemical cycling research of arsenic. |
| File Format |
HTM / HTML |
| ISSN |
0166445X |
| Volume Number |
157 |
| e-ISSN |
18791514 |
| Journal |
Aquatic Toxicology |
| Language |
English |
| Publisher |
Elsevier |
| Publisher Date |
2014-12-01 |
| Publisher Place |
Netherlands |
| Access Restriction |
One Nation One Subscription (ONOS) |
| Subject Keyword |
Discipline Toxicology Arsenites Metabolism Toxicity Chlamydomonas Reinhardtii Drug Effects Nitrogen Pharmacology Arsenates Analysis Arsenic Logistic Models Oxidation-reduction Phosphorus Toxicity Tests Water Pollutants, Chemical Journal Article Research Support, Non-u.s. Gov't |
| Content Type |
Text |
| Resource Type |
Article |
| Subject |
Health, Toxicology and Mutagenesis Aquatic Science |
