Asemoloye Michael Dare, Ahmad Rafiq, Jonathan Segun Gbolagade
Food and Environmental Mycology/Biotechnology Unit, Department of Botany, University of Ibadan, Ibadan, Nigeria; Department of Environmental Sciences, COMSATS Institute of Information Technology, 22060, Abbottabad, Pakistan.
Department of Environmental Sciences, COMSATS Institute of Information Technology, 22060, Abbottabad, Pakistan.
Chemosphere. 2017 Nov;187:1-10. doi: 10.1016/j.chemosphere.2017.07.158. Epub 2017 Aug 2.
This study was aimed at combining the potentials of plant and some rhizospheric fungal strains in remediation of crude-oil polluted soil. Four new rhizospheric fungi were identified from an aged crude-oil polluted site and used with Megathyrsus maximus (guinea grass) for a 90 day synergistic remediation experiment. Cultures of these strains were first mixed with spent mushroom compost (SMC), the mixture was then applied to a sterilized crude oil polluted soil at concentrations of 10%, 20%, 30% and 40% potted in three replicates. Soil with plant alone (0%) and soil with fungi-SMC alone (0%) served as controls. The soil's initial and final pH, nutrient, 16 EPA PAHs and heavy metal contents were determined, degradation rate, half-life and percentage loss of the total polyaromatic hydrocarbon (TPAH) were also calculated. Finally, the remediated soils were further screened for seed germination supporting index. The fungal strains were identified and registered at NCBI as Aspergillus niger asemoA (KY473958.1), Talaromyces purpurogenus asemoF (KY488463.1), Trichoderma harzianum asemoJ (KY488466.1) and Aspergillus flavus asemoM (KY488467.1). We observed for the first time that the synergistic mechanism improved the soil nutrient, reduced the heavy metal concentration and sped up hydrocarbon degradation rate. Using the initial and final concentrations of the TPAH, we recorded highest biodegradation rates (K) and half-life (t) in 30 and 40% treatments over controls, these treatments also had highest seed germination supporting index. This work suggests that the set-up synergistic remediation could be used to remediate crude oil polluted soil and this could be used in large scale.
本研究旨在结合植物和一些根际真菌菌株在修复原油污染土壤方面的潜力。从一个长期受原油污染的场地中鉴定出四种新的根际真菌，并将其与大黍（几内亚草）一起用于为期90天的协同修复实验。首先将这些菌株的培养物与废蘑菇堆肥（SMC）混合，然后将混合物以10%、20%、30%和40%的浓度施用于灭菌后的原油污染土壤中，每个浓度设置三个重复盆栽。仅种植植物的土壤（0%）和仅含真菌-SMC的土壤（0%）作为对照。测定了土壤的初始和最终pH值、养分、16种美国环保署（EPA）多环芳烃（PAHs）和重金属含量，还计算了降解率、半衰期和总多环芳烃（TPAH）的损失百分比。最后，对修复后的土壤进一步筛选种子发芽支持指数。这些真菌菌株在NCBI上被鉴定并登记为黑曲霉asemoA（KY473958.1）、产紫青霉asemoF（KY488463.1）、哈茨木霉asemoJ（KY488466.1）和黄曲霉asemoM（KY488467.1）。我们首次观察到协同机制改善了土壤养分，降低了重金属浓度，并加快了碳氢化合物的降解速率。利用TPAH的初始和最终浓度，我们记录到在30%和40%处理中，相对于对照，生物降解率（K）和半衰期（t）最高，这些处理的种子发芽支持指数也最高。这项工作表明，所建立的协同修复方法可用于修复原油污染土壤，并且可大规模应用。
