高效降解烷烃的无色杆菌X_L株的分离鉴定及其降解特性

从山东东营胜利油田附近被石油污染的土壤中,通过逐步驯化筛选原油降解菌株,并对其降解特性进行研究。结果表明:①分离到一株以原油为唯一碳源,且摇瓶培养对原油降解率高达72.6%的降解菌XL。②通过形态、生理生化和16 SrDNA序列分析,XL与木糖氧化无色杆菌(Achromobacter xylosoxidans)的同源性达99.0%,最终确定为木糖氧化无色杆菌(Achromobacter xylosoxidans)。③通过GC-MS分析表明,菌株对C12-C23和C27-C43的烷烃几乎能彻底降解,说明菌株具有高效较宽的烷烃降解谱。④XL菌株发酵液溶血圈和排油圈直径较大,分别为3.6 cm和4.7 cm,说明其能产生表面活性剂。⑤通过油污土壤的室内外培养降解试验发现,当土壤中原油含量为10%时,锯末、秸秆、菌剂及N、P营养物协同处理60 d后,土壤原油降解率为79.5%(室内)和71.0%(室外),明显高于仅加菌剂或加菌剂+N、P营养物的处理组。⑥室外堆制试验中,XL菌株对石油污染物的降解速度、能力均低于室内的。

Isolation and Identification of a High-Efficiency Alkane-Degrading Achromobacter insolitus X_L Strain and Its Degradation Characteristics

Petroleum-degrading XL strain was obtained by using the method of gradient dilution and petroleum selective cultivation from contaminated soil samples collected from Shengli oil field in Dongying of Shandong.Then the characteristics of the degradation were studied.The result was as followed: ①The test in shaking flasks showed that it could degrade petroleum hydrocarbon well and the degradation rate could reach 72.6% at 14d.②The isolated strain was identified according to morphological,physiological and biochemical characters respectively,and 16Sr DNA of strain was sequenced.The results of identification demonstrated that XL strain was Achomoobacter xylosoxidans.③GC-MS analysis showed C12-C23 and C26-C43 n-alkyl benzene could be degraded markedly.④XL had capability of the relative draining oil and dissolving blood,which implied it could produce bio-surfactant.⑤The rates of oil degradation were 79.5% and 71.0% respectively by laboratory simulation after 60-day inoculation of oil-degrading bacteria in combination of N,P,sawdust and straw,which was evidently higher than single degrading bacteria amendment or degrading bacteria plus N and P nutrition.⑥The degradation rates and capacity of XL in the outside compost were lower than those in laboratory simulation.