Degradation of fluorene and phenanthrene in PAHs-contaminated soil using Pseudomonas and Bacillus strains isolated from oil spill sites
Degradation of fluorene and phenanthrene in PAHs-contaminated soil using Pseudomonas and Bacillus strains isolated from oil spill sites
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DOI：
10.1016/j.jenvman.2018.11.005
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发表时间：
2019-02-15
影响因子：
8.7
通讯作者：
Ouddane, B.
中科院分区：
文献类型：
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作者：
Rabodonirina, S.;Rasolomampianina, R.;Ouddane, B.
研究了3环和4环多环芳烃（PAHs）模型（芴、菲、氟蒽和芘）的生物降解。从污染菌中分离出27株菌株。漏油现场。对多环芳烃降解菌进行筛选，筛选出耐受性高的菌种，确保有效的生物修复。分别在不同浓度（250、500、1000和1500 mg/L）下培养分离菌株。27株菌株中，有8株菌株对高浓度多环芳烃（1500 mg/L）具有抗性，可以利用多环芳烃作为唯一的碳源和能量来源。采用MALDI-TOF VITEK MS和16S rDNA测序方法对耐药菌株进行分子鉴定。利用鉴定出的stutzeri假单胞菌（P. stutzeri）、单纯芽孢杆菌（B. simplex）和短小芽孢杆菌（B. pumilus）菌株对被多环芳烃污染的土壤进行生物修复试验。研究是在受控条件下进行的，土壤中添加了目标多环芳烃和三种微观菌株的混合物。结果表明，在试验生物培养72天内，只有低分子量的多环芳烃芴和菲被有效降解。对芴和菲的降解率分别为65-86%和86-95%。同时，与芴和菲相反，高分子量的多环芳烃、芘和荧光蒽对这些选定的微生物菌株具有抗性。在R-2值为0.88 ~ 0.92的范围内，芴和菲的生物降解动力学均符合一级速率。菲的半衰期（2.4 ~ 2.7 d）和芴的半衰期（3.5 ~ 4.6 d）均小于10 d，说明菌株已驯化。
Biodegradation of 3-ring and 4-ring polycyclic aromatic hydrocarbons (PAHs) model (fluorene, phenanthrene, fluoranthene and pyrene) were investigated. Twenty-seven bacterial strains were isolated from contaminated. site by oil spills. PAHs-degrading bacteria were screened to select high tolerant species for ensuring an efficient bioremediation. Each of the isolated bacterial strains was grown under different PAHs concentrations (250, 500, 1000 and 1500 mg/L). Among the 27 strains, 8 resulted to be resistant to high concentration level of PAHs (1500 mg/L) and thereof can use PAHs as sole source of carbon and energy. The most tolerant strains were molecularly identified using mass spectrometer MALDI-TOF VITEK MS and 16S rDNA sequencing approaches. The identified bacterial strains Pseudomonas stutzeri (P. stutzeri), Bacillus simplex (B. simplex) and Bacillus pumilus (B. pumilus) were used for the bioremediation experiment of soils contaminated by PAHs. The studies were conducted under controlled conditions using soil spiked with a mixture of the target PAHs and the three microcosm strains. The results revealed that only fluorene and phenanthrene, which are low molecular weight PAHs, were degraded efficiently within 72 days of test organism incubation. These degradations were about 65-86% and 86-95% for fluorene and phenanthrene, respectively. At the same time and conversely to fluorene and phenanthrene, the high molecular weight PAHs, pyrene and fluoranthene were recalcitrant to these selected microbial strains. The biodegradation kinetics of both fluorene and phenanthrene were fit a first order rate with R-2 values ranging from 0.88 to 0.92. The half-lives of phenanthrene (2.4-2.7 days) and those of fluorene (3.5-4.6 days) were all less than 10 days, delineating therefore acclimatization with the strains.