Analysis of microbial potential of a biopile in soil bioremediation contaminated by petroleum hydrocarbons

ABSTRACT This research evaluated the microbial potential of a biopile in bioremediation of soils contaminated by hydrocarbons, mounted on a fuel distribution base in the metropolitan region of Porto Alegre, Rio Grande do Sul. Of this biopile were evaluated concentrations of total petroleum hydrocarbons (TPH) and benzene compounds, toluene, ethylbenzene and xylenes (BTEX) at nine points, for four stages of operation and a point in three depths. Of each collection were also reserved sampled soil to perform the microbiological testing. From the samples, we sought to identify fungi and yeasts by analyzing their reproductive structures microcultivation blades, and bacteria by the technique of Polymerase Reaction Chair (PCR) and gene sequencing encoding the 16S rRNA. Still, we evaluated the ability of microorganisms to degrade commercial diesel oil, using the redox indicator 2,6-dichlorophenol indophenol (DCPIP). As result of this study, there was a high percentage reduction in the concentration of TPH and BTEX in biopilha as 92 and 100%, respectively. Of soil samples were isolated from biopilha 101 strains of microorganisms, of which 19 were identified strains of filamentous fungi and 34 bacterial yeast. The results showed the ability of some genera of fungi such as Aspergillus, Trichoderma, Penicillium, Cladosporium and Verticillium and bacteria such as Bacillus spp. and Streptomyces sp. to degrade hydrocarbons constituents of commercial diesel oil.

摘要
本研究评估了位于巴西南里奥格兰德州阿雷格里港都会区某燃油配送基地的生物堆（biopile）在烃类污染土壤生物修复中的微生物应用潜力。针对该生物堆，本研究在9个采样点、4个运行阶段下，于每个采样点的3个深度层级测定了总石油烃（total petroleum hydrocarbons, TPH）以及苯、甲苯、乙苯、二甲苯（BTEX）的浓度；同时留存每份采集的土壤样品以开展微生物学检测。
针对所得样品，本研究通过微培养玻片观察真菌及酵母菌的生殖结构以完成种类鉴定，同时采用聚合酶链式反应（Polymerase Chain Reaction, PCR）及16S rRNA编码基因测序技术鉴定细菌种类。此外，本研究以2,6-二氯吲哚酚（2,6-dichlorophenol indophenol, DCPIP）作为氧化还原指示剂，测定了微生物降解商用柴油的能力。
本研究结果显示，生物堆内总石油烃与苯系物的浓度分别降低了92%与100%，降幅显著。从该生物堆的土壤样品中共分离得到101株微生物，其中19株经鉴定为丝状真菌，34株为酵母菌及细菌。研究结果表明，曲霉属（Aspergillus）、木霉属（Trichoderma）、青霉属（Penicillium）、枝孢属（Cladosporium）及轮枝孢属（Verticillium）等真菌，以及芽孢杆菌属（Bacillus spp.）、链霉菌属（Streptomyces sp.）等细菌，均具备降解商用柴油中烃类组分的能力。