北戴河滨海湿地根际石油降解菌的筛选及功能分析

Isolation and functional evaluation of oil degrading bacteria in the rhizosphere of Beidaihe coastal wetlands

以北戴河碱蓬-芦苇滨海湿地采集的5个根际土壤样品为研究材料,使用以原油为唯一碳源的选择培养基富集培养石油降解菌,采用重量法评价降解效率,通过GC-MS分析研究高效降解菌的降解特性,利用排油圈法测定降解菌的表面活性剂产生能力。研究结果表明,初筛获得22株石油降解菌,在25℃降解21d的条件下对石油的降解率为17%～38%,其中qhd2B降解率最高,为38%,其中8株具有较好的产表面活性剂的能力。16s测序结果经BLAST比对,所分离获得的22株菌中,8株菌属于放线菌门(Actinobacteria),13株菌属于变形菌门(Proteobacteria),有一株拟杆菌门(Bacteroidetes)丽水菌属(Yeosuana)。选取石油降解率在31%以上菌株进行GC-MS分析,结果显示其对大部分烷烃和多环芳香烃都有较好的降解效果。其中菌株qhd2B对烷烃和芳烃的总降解率分别为79.9%和76.7%,是一株优良的石油降解菌。

5 samples of rhizosphere sediment samples collected in coastal wetlands of suaeda glauca-phragmites australis in Beidaihe as the research materials, the oil-degrading bacteria were enriched by selective medium with oil as the sole carbon source, the degradation efficiency was evaluated by gravimetric method, and the degradation characteristics of the highly efficient degrading bacteria were studied by GC-MS analysis. The results showed that the oil degradation rate of oil degrading bacteria isolated was 17%-38% at 25℃ and 21 days after degradation. Among them, the degradation rate of qhd2B was the highest, reaching 38%;and 8 of them had good ability of producing surfactant. 16S sequencing results were compared with BLAST tools. 8 of the 22 isolates were isolated from Actinomycetes, 13 strains belonged to Proteobacteria, and one strain belonged to Yeosuana genus of Bacteriomycetes. GC-MS analysis was carried out for the strain more than 31% of the oil degradation rate. The results showed that most of the alkanes and PAHs hydrocarbons had good degradation effect. Among them, the total degradation rate of strain qhd2B to alkanes and PAHs was 79.9% and 76.7% respectively, which was an excellent oil degrading bacteria.