丝状真菌的混合菌群降解原油的条件与效果

Condition and Effect of Degrading Crude Oil by Mixed Strain Group of Filamentous Fungi

[目的]优化丝状真菌混合菌群降解原油的环境条件。[方法]从原油污染的土壤和海水中分离并筛选到对原油降解率较高的丝状真菌菌株,由S-3(HyphochytriumZopf)、T-1(Dictyuchus leitgeb)和T-2(Pythiwm pringsheim)构建混合菌群X3,通过单因素试验和正交试验确定菌群降解原油的最佳环境条件以及3种菌株不同接种比例对原油降解的影响效果。[结果]单因素试验结果表明,菌群X3的最适氮源为(NH4)2SO4,最适磷源为K2HPO4,最适pH值范围为6.0～7.0,最适摇床转速130～195 r/min。正交试验表明,S-3、T-1和T-2菌株的最适接种比例为1∶0.4∶1,优化后的最佳原油降解条件为:(NH4)2SO41.0 g/L、K2HPO41.5 g/L、pH值6.0、接种量0.5%,原油浓度1.25 g/L。在对原油污染的土壤和海水进行的室内修复试验中,X3菌群对原油的降解率分别达到72%和66%。[结论]混合菌群X3在石油污染生物修复中具有实际应用价值。

[Objective] The study aimed to optimized the environment condition of degrading the crude oil by mixed strain group of filamentous fungi.[Method] The filamentous fungi strains were isolated and screened from the soil and seawater conta minated by the crude oil and the mixed fungi group X3 was constructed by filamentous fungi S-3（Hyphochytrium Zopf）,T-1（Dictyuchus leitgeb） and T-2（Pythiwm pringsheim）.The optimum environment condition of degrading the crude oil by mixed strain group of filamentous fungi was confirmed and the effects of 3 kinds of strains with different inoculation proportion on the crude oil degradation were studied through single factor test and the orthogonal test.[Result] The single factor test shows that the optimum N source,P source,initial pH values and rotating speed of shaking table for X3 were deter mined as（NH4）2SO4,K2HPO4,pH 6.0-7.0 and 130-195 r/min resp.The orthogonal experiment showed that the most suitable proportion of strains S-3∶T-1∶T-2 was 1∶0.4∶1;the optimum condition of degrading the crude oil after optimization was as follows：（NH4）2SO4 was1.0 g/L,K2HPO4 was 1.5 g/L,pH was 6.0,the inoculation volume was 0.5% and the crude oil content was 1.25 g/L.The results from the bioremediation experiment on the petroleum-polluted soil and seawater in the laboratory showed that the crude oil degradation rate was 72% and 66% by the mixed fungi group X3 resp.[Conclusion] The mixed fungi group X3 had the practical application value in the petroleum-polluted bioremediation.