石油污染土壤鞘氨醇单胞菌遗传多样性16S rDNA-PCR-DGGE分析

鞘氨醇单胞菌是降解多环芳烃(PAHs)的重要功能微生物。然而,采用属特异引物直接从PAHs污染土壤中检测鞘氨醇单胞菌进而研究鞘氨醇单胞菌在污染土壤中的多样性、种群结构及其与PAHs污染的关系鲜有报道。本研究自行设计鞘氨醇单胞菌属特异性引物,通过16S rDNA-PCR-DGGE技术对沈抚灌区石油污染土壤鞘氨醇单胞菌遗传多样性进行了研究。结果表明,自行设计的鞘氨醇单胞菌属引物732f-982r能够特异、灵敏的从环境样品中检出鞘氨醇单胞菌。当沈抚灌区原位污染土壤的PAHs浓度小于5 mg kg-1时,鞘氨醇单胞菌多样性随着PAHs浓度的增加而增加;而初始PAHs浓度高的实验室模拟实验土壤,其鞘氨醇单胞菌多样性较低。鞘氨醇单胞菌种群结构受污染土壤总石油烃(TPH)含量的影响,TPH含量接近的土壤,鞘氨醇单胞菌的群落结构较为相似。

Analysis of Sphingomonas genetic diversity in petroleum-contaminated soils by using PCR-DGGE technique

Members of Sphingomonas genus played a key role in the biodegradation of polycyclic aromatic hydrocarbons (PAHs). However, little was available in the literature about diversity and population structure of genus Sphingomonas in petroleum-contaminated soils, and relationships between Sphingomonas and PAHs based on direct detection Sphingomonas strains with Sphingomonas genus-specific primers. In this paper, total soil DNA from the soil in Shenfu irrigation zone were amplified with newly designed Sphingomonas genus-specific primer set 732f-982r and then these amplified DNA fragments were separated by DGGE for analysis of genetic diversity of Sphingomonas in the soil of the irrigation zone. Results indicate that the newly developed primer set 732f-982r could be used for specific detection of strains belonging to the genus Sphingomonas. When PAHs contamination of the soil is at a low level, i.e. less than 5 mg kg-1, the diversity of Sphingomonas increased with rising PAHs concentration; but when the initial concentration of PAHs in lab incubation experiment is relatively high, the diversity of Sphingomonas decreased. Different concentrations of total petroleum hydrocarbons (TPH) lead to difference in Sphingomonas population, and soils the same in TPH contamination level are similar in Sphingomonas population.