The toxicity of naphthalene to marine Chlorella vulgaris under different nutrient conditions.
The toxicity of naphthalene to Chlorella vulgaris was studied under nitrogen (N)-, phosphorus (P)-enriched and N,P-starved condition. Results showed that naphthalene was less toxic under N,P-starved condition. The inhibitory rates were less than 15.3% to C. vulgaris during 7 days exposure with the initial concentrations of naphthalene at 5, 10, 50, 100mg/L, respectively under N,P-starved condition, while they were 7.5-72.3% under N,P-enriched condition. The malondialdehyde (MDA) content indicated that there was no oxidative damage to algae when the initial concentration of naphthalene was less than 10mg/L, and oxidative damage exhibited to algae at 50-100mg/L of naphthalene under N,P-starved condition. Naphthalene induced oxidative damage to the algae at all tested concentrations (5-100mg/L) under N,P-enriched condition. The results indicated that there was a negative relationship between the special growth rate (SGR) and naphthalene concentration in the medium. Under N,P-enriched condition SGR of the control decreased slowly from 0.669 to 0.186. However, SGR of the naphthalene treated group decreased sharply during the first 2-3 days when the dissolved concentration of naphthalene was above 0.1mg/L, and then increased gradually with the evaporation of naphthalene.
Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028, China.
Qingxia
Q
Kong
Lizhong
L
Zhu
Xueyou
X
Shen
D048408:Chlorella vulgaris / Q000187:drug effects* / Q000254:growth & development; D003470:Culture Media; D008315:Malondialdehyde / Q000737:chemistry; D009281:Naphthalenes / Q000633:toxicity*; D009584:Nitrogen / Q000378:metabolism; D009747:Nutritional Physiological Phenomena; D010758:Phosphorus / Q000378:metabolism; D012623:Seawater / Q000032:analysis
D003470:Culture Media; D009281:Naphthalenes; C031721:naphthalene; D010758:Phosphorus; D008315:Malondialdehyde; D009584:Nitrogen