菲降解菌的分离鉴定及其在污染土壤生物修复中的应用

采用室内培养方法,从吴江市郊长期被多环芳烃污染的土壤中富集到以菲为唯一碳源和能源的菲降解复合微生物菌群,复合菌群在7d内对无机盐液体中菲(含量100mg·L-1)的降解率达到99%。从复合菌群中分离纯化获得两株菲高效降解菌B1和L2,经过菌体形态特征、生理生化特征和16SrDNA序列分析,鉴定菌株B1为百日咳博行特氏菌(Bordetella petrii),菌株L2为墨西哥假黄单胞菌(Pseudoxanthomonas mexicana)。这两株菌在菲含量为100mg·L-1的无机盐培养液中,7d内对菲(含量100mg·L-1)的降解率大约为80%,9d内的降解率可达到99%。将复合菌群和菲污染土壤混合,在光照培养箱中进行培养修复。结果表明,修复88d后,接种复合菌群的低污染浓度(8.22mg·kg-1)处理和高污染浓度(39.65mg·kg-1)处理的菲去除率分别达到95.74%和98.06%。

Isolation and Identification of Phenanthrene Degrading Bacteria and Their Roles in Bioremediation of Phenanthrene-contaminated Soil

In this study,a microbial consortium which could degrade phenanthrene and take phenanthrene as the sole carbon and energy source wero obtained from an aged PAHs-contaminated soil.The microbial consortium could metabolise 99%of phenanthrene within 7 days in a mineral medium containing 100 mg·L~(-1) phenanthrene.Two phenanthrene-degrading microorganisms,B1 and 1.2,were isolated from the consortium.Based on Physiological properties and 16S rDNA,those two strains were identified as Bordetella petrii and Pseudoxanthomonas mexicana,respectively.The degradation rate of phenanthrene in the mineral medium was about 80% by Bordetella petrii B1 within 7 days and 99% by Pseudoxanthomonas mexicana L2 within 9days.After 88 days of soil remediation by the microbial consortium.the degradation rate of phenanthrene reached upto 95.74％ for the soil containing 8.22mg·kg~(-1) of phenanthrene and 98.06％forthesoil containing 39.65 mg·kg~(-1) of phenanthrene.