一株丝状蓝藻的分离鉴定及其对原油耐受性能的研究

从石油污染的港口水域分离筛选到一株丝状蓝藻GH1,通过形态学和分子生物学分析鉴定为颤藻.从生长情况和抗氧化酶活性方面研究了这株颤藻对原油的耐受性.在0～20d培养过程中,原油培养条件下GH1的叶绿素增长更快,第7天即达到生长稳定期;可溶性蛋白含量随时间的变化呈先上升后下降的趋势,原油样品的可溶性蛋白含量始终要显著高于空白样.在0～1%体积浓度范围内,第7天测定原油样品中颤藻叶绿素和可溶性蛋白含量均明显高于空白样.对抗氧化酶系统而言,在原油培养条件下,培养初期超氧化物歧化酶SOD(Superoxide Dismutase)和过氧化氢酶CAT(Catalase)活性显著高于空白样,随着培养时间增加,SOD和CAT活性呈下降趋势,而过氧化物酶POD(Peroxidase)活性一直呈上升趋势.低浓度原油能刺激3种抗氧化酶活性都升高,高浓度原油对SOD和CAT活性有抑制作用,但POD活性仍能随原油浓度增加而升高.在原油中毒性物质的胁迫下,POD与SOD、CAT的响应表现为互补的变化趋势,3种酶共同防御作用是颤藻GH1耐受原油胁迫的主要机制.

Isolation and identification of a filamentous cyanobacterium and its tolerance for crude oil

A filamentous cyanobacterium strain GH1 was isolated from oil-contaminated water collected from Huangpu Port, and was identified as Oscillatoriales by using morphological and molecular methods. The tolerance of crude oil of the strain GH1 was studied from two aspects including its growth and the activity of antioxidant enzyme. The chlorophyll of Oscillatoriales GH1 in the cultivation with crude oil was increased more rapid than the control, and could achieve the stable breading period in the 7th day. The contents of soluble protein were increased first but decreased afterwards during the 20d cultivation. The concentrations of soluble protein in the samples under crude oil condition were always significantly higher than those in control group. Both concentrations of soluble protein and chlorophyll were promoted by 0~1% (v:v) crude oil. For the antioxidant enzyme system, the activities of superoxide dismutase (SOD) and catalase (CAT) were significantly higher than the control group in the initial culture stage with crude oil cultivation. The SOD and CAT decreased but peroxidase (POD) keep increasing with time. All these three antioxidant enzymes were promoted by low concentration of crude oil. High concentration of crude oil could inhibit the activity of SOD and CAT, while the activity of POD still increased with the increasing of crude oil. There should have a complementary effect between SOD, CAT and POD to resist the toxic substances in crude oil. This complementary cooperation of the three enzymes would be the main mechanism for Oscillatoriales GH1 to tolerate crude oil.