海绵动物共附生微生物对海洋柴油污染物的降解作用及影响

Degradation and influence of sponges co-adherent microorganisms on marine diesel pollutants

目的探索海绵动物共附生微生物对海洋柴油污染的生物修复作用。方法以柴油降解率为指标从海绵中筛选降烃菌株,对降烃效果较好的3种菌株进行鉴定和复配,选出最佳降烃组合开展单因素试验和响应面优化试验,并构建柴油污染模型验证生物修复效果。结果筛选降烃菌共38株,其中降烃效果最好的D1、D7、D8菌株分别鉴定为Halomonas aquamarina、Sphingopyxis terrae、Marinobacter aquaeolei;其降解率均在65%以上;3种菌株复配后优选最佳组合为D1-D7-D8;对降烃效果影响较大的3因素为初始pH值、柴油质量浓度和温度;对其响应面优化后得出最佳降解条件分别为7.41、32.79 g/L、30.65℃;按最优条件构建的模型实际降解率为84.17%,与预测值86.27%的吻合度较好。结论该研究可为海绵-降烃菌系共生体的构建提供理论支撑,为解决海水中柴油污染难以集中处理的问题开辟新途径。

Objective The bioremediation effect of sponge-associated microorganisms on marine diesel pollution is to be explored.Methods Diesel-degrading bacteria strains were screened from sponge-associated microorganism based on diesel degradation rate,and 3 strains were selected for identification and composite analysis.The best combination was selected to carry out the single-factor test and response surface optimization test,and a diesel pollution model was constructed to verify the effect of bioremediation.Results 38 diesel-degrading bacteria strains were screened.Among them,D1,D7 and D8 with the best hydrocarbon-reducing effect were identified as Halomonas aquamarina,Sphingopyxis terrae and Marinobacter aquaeolei respectively,and their degradation rates were all above 65%.The best combination is D1-D7-D8;and the three factors that affect the hydrocarbon reduction effect were the initial pH value,concentration of diesel oil,and temperature.Based on the response surface methodology,the optimal degradation conditions were identified to be as follow:initial pH value at 7.41,concentration of diesel oil at 32.79 g/L,and the temperature at 30.65℃.The actual degradation rate of the model constructed under the optimal conditions was 84.17%,which was in good agreement with the predicted value of 86.27%.Conclusions This study can provide theoretical support for the construction of sponge-hydrocarbon-depressing bacteria symbionts,and open up a new way to solve the problem that diesel pollution in seawater is difficult to be centralized.