小球藻和盐藻利用石油烃富集油脂的研究

Lipid enrichment of Chlorellasp.and Dunaliella salina by degradation of petroleum hydrocarbons

利用单细胞分离和紫外诱变技术分别获得海水小球藻和盐生杜氏藻的生长优势株,将其分别接种于不同石油浓度的海水培养液中,利用紫外和荧光分光光度法分别测定培养液中带共轭双键的烃类化合物和芳烃的含量,利用索氏提取法测定胞内油脂含量。结果表明,石油浓度为1.5～10.0μg/ml的培养液中,小球藻和盐藻均能有效降解带共轭双键的烃类化合物,降解率分别为25.3%～35.5%和17.9%～24.0%,芳烃降解率分别为22.1%～30.2%和18.7%～26.2%;石油浓度为3.5μg/ml时,两种微藻对带共轭双键的烃类化合物和芳烃的降解效率均最大,小球藻的降解能力略好于盐藻;石油浓度为1.5μg/ml和3.5μg/ml时,两种微藻的胞内油脂含量分别占细胞干重的14.0%和25.5%,分别是对照组的1.5倍和1.2倍,浓度为3.5μg/ml时两种微藻的胞内油脂含量均最高。该研究为利用石油污染海水培养微藻使其富集油脂及今后开发微藻燃料奠定了基础。

This study aims to investigate the possibility of using marine microalgae （green microalgae） to degrade petroleum hydrocarbons and converse them into lipids in cells. Rapid growth strains of Chlorella sp. and Dunaliella salina were obtained by single separation tech- nology and ultraviolet mutation breeding techniques. The mutagenesis dominant strains were then cultured in oily seawater with different oil concentrations. The contents of conjugated hy- drocarbon compounds and petroleum aromatic hydrocarbons were determined respectively by UV spectrophotometry and fluorescence speetrophotometry. The lipid content of the microalgae cells was measured by the Soxhlet extraction method. The results showed that Chlorella and D. salina were able to degrade petroleum hydrocarbons effectively at oil concentrations of 1.5 -10.0μg/ml. The degradation rates of conjugated hydrocarbon compounds were 25.3% -39.5% and 17.9% -24.0%, respectively, while the degradation rates o{ petroleum aromatic hydrocar- bons were 18.7%-26.2% and 22.1%-30.2%, respectively, Degradation rates for both pe- troleum hydrocarbons were the highest at oil concentration of 3.5μg/ml, and the performance of Chlorella was slightly better than D. salina. The lipid contents of the algal cells were 1.2 and 1.5 folds of the control when cultured in oily seawater at oil concentrations of 1.5μg/ml and 3.5μg/ml, and the lipid content of the algal cells was the highest for the latter.