原油分散液对小新月菱形藻C、N稳定同位素组成的影响

Effect of crude oil dispersion on carbon and nitrogen stable isotopic composition of Nitzschia closterium

以微藻类小新月菱形藻(Nitzschia closterium)为研究对象,通过设置不同的原油分散液(WAF)浓度,分别进行了急性(4 d)和亚急性(29 d)毒理实验;通过细胞计数、丙二醛(MDA)测定、稳定同位素组成分析等方法测定了原油分散液(WAF)对小新月菱形藻生长曲线、C和N稳定同位素组成(δ13C、δ15N值)的影响。结果表明,WAF在低浓度(≤1.0 mg/L)长期作用下对小新月菱形藻的生长有促进作用,而较高浓度(≥5.0 mg/L)则使藻细胞生长受到抑制;小新月菱形藻的丙二醛含量随时间及WAF浓度增大而逐渐增加,最高可达1.65倍。WAF在低浓度(≤1.0 mg/L)作用下,藻细胞的δ13C、δ15N值都趋于增大,而较高浓度(≥5.0 mg/L)则使藻细胞的δ13C、δ15N值趋于变小,这表明,微藻类的C、N稳定同位素组成能够从一定程度上反映污染程度,因此可作为海洋溢油污染监测的一种新指标。

This study made acute（ 4 d） and chronic（ 29 d） experiments by setting different oil concentrations（ WAF） and using Nitzschia closterium as the research object. We measured the effects of WAF on N. closterium by cell counting,malondialdehyde（ MDA） measuring and the carbon / nitrogen stable isotopic analyses. The results show that WAF stimulated the growth of N. closterium in low concentration（ ≤1. 0 mg / L）,while the growth of N. closterium was restrained in relatively high concentrations（ ≥5. 0 mg / L）. The MDA content increased with the growth time and the increase of WAF concentration,up to the maximum of 1. 65 times. The δ13C and δ15N value was higher in low concentration（ ≤1. 0 mg / L）,while lower in relatively high concentration（ ≥5. 0 mg / L）. Therefor the stable isotopic composition of microalgae may be used as an alternative method for oil pollution monitoring.