CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123, Porto, Portugal.
Biodegradation. 2013 Feb;24(1):111-23. doi: 10.1007/s10532-012-9562-9. Epub 2012 Jun 13.
In this work, the potential effect of metals, such as Cd, Cu and Pb, on the biodegradation of petroleum hydrocarbons in estuarine sediments was investigated under laboratory conditions. Sandy and muddy non-vegetated sediments were collected in the Lima River estuary (NW Portugal) and spiked with crude oil and each of the metals. Spiked sediments were left in the dark under constant shaking for 15 days, after which crude oil biodegradation was evaluated. To estimate microbial abundance, total cell counts were obtained by DAPI staining and microbial community structure was characterized by ARISA. Culturable hydrocarbon degraders were determined using a modified most probable number protocol. Total petroleum hydrocarbons concentrations were analysed by Fourier Transform Infrared Spectroscopy after their extraction by sonication, and metal contents were determined by atomic absorption spectrometry. The results obtained showed that microbial communities had the potential to degrade petroleum hydrocarbons, with a maximum of 32 % degradation obtained for sandy sediments. Both crude oil and metals changed the microbial community structure, being the higher effect observed for Cu. Also, among the studied metals, only Cu displayed measurable deleterious effect on the hydrocarbons degradation process, as shown by a decrease in the hydrocarbon degrading microorganisms abundance and in the hydrocarbon degradation rates. Both degradation potential and metal influence varied with sediment characteristics probably due to differences in contaminant bioavailability, a feature that should be taken into account in developing bioremediation strategies for co-contaminated estuarine sites.
在这项工作中，研究了在实验室条件下，金属（如 Cd、Cu 和 Pb）对河口沉积物中石油烃生物降解的潜在影响。在葡萄牙西北部的利马河口采集了沙质和泥质无植被沉积物，并向其中添加了原油和每种金属。添加了金属的污染沉积物在黑暗中保持恒定摇动 15 天，然后评估原油的生物降解情况。为了估计微生物丰度，通过 DAPI 染色获得总细胞计数，并通过 ARISA 表征微生物群落结构。使用改良的最可能数方案确定可培养的烃降解菌。通过超声提取后，采用傅里叶变换红外光谱法分析总石油烃浓度，并通过原子吸收光谱法测定金属含量。结果表明，微生物群落具有降解石油烃的潜力，沙质沉积物的最大降解率可达 32%。原油和金属都改变了微生物群落结构，Cu 的影响最大。此外，在所研究的金属中，只有 Cu 对烃降解过程表现出可测量的有害影响，这表现为烃降解微生物丰度和烃降解率的下降。降解潜力和金属的影响因沉积物特性而异，这可能是由于污染物生物可利用性的差异造成的，在开发用于受污染河口的生物修复策略时应考虑这一特征。
