溢油对小新月菱形藻氨基酸相对含量变化的影响

Effects of oil spill on the relative abundances of amino acids in Nitzschia closterium

以小新月菱形藻(Nitzschia closterium)为受试生物,在96 h急性毒性实验条件下,设置不同浓度的180#燃料油分散液(WAF),分析小新月菱形藻细胞内氨基酸相对含量的变化.结果表明,随着培养时间增加,对照组(Ctrl)和低浓度WAF(1%和3%)中丙氨酸和组氨酸相对含量呈上升趋势,而在高浓度WAF(5%、7%和10%)组中丙氨酸无明显变化趋势,组氨酸则呈先降低后升高的趋势.在对照组和低浓度WAF组(1%和3%)下,半胱氨酸相对含量随培养时间增加而减少,而高浓度WAF(5%、7%和10%)下,变化趋势与低浓度相反.在各WAF浓度下,脯氨酸相对含量均随着培养时间的增加而增加,而天冬氨酸的变化正好与脯氨酸相反.因此,本研究发现小新月菱形藻内的主要氨基酸对180#燃料油分散液具有敏感的生化反应,可作为海洋污染检测的一种新途径.

Nitzschia closterium( N. closterium) was selected as the test organism to study the toxicity effects of 180 # fuel oil water accommodated fractions( WAF) during the exposure time of 96 h in the present study. The relative abundance of amino acids in the cells of N. closterium were measured.The results showed that the relative abundance of alanine( Ala) and histidine( His) increased with increasing culture time in the control group and low WAF concentrations( 1% and 3%). However,the change of Ala was not obvious in the high WAF concentrations( 5%,7% and 10%),and the abundance of His first decreased and then increased. The relative abundance of cysteine( Cys) in the control group and low WAF concentrations( 1% and 3%) decreased with the increase of culture time,while variation trend was opposite in the high WAF concentrations( 5%,7% and 10%).The relative abundance of proline( Pro) increased with increasing culture time in all the WAF concentrations,and the change of aspartic acid( Asp) was just opposite to the trend of Pro. The study shows that the main amino acids in N. closterium are sensitive to the 180 # fuel oil WAF,which can serve as the new approach to monitor the marine pollution caused by the oil spill.