Department of Chemical Engineering, Universidad Autónoma de San Luis Potosí, Coordinación Académica Región Altiplano, Carretera a Cedral Km 5+600, San José de las Trojes, Matehuala City, San Luis Potosí, Mexico.
Department of Genetic and Molecular Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Zacatenco, Av. IPN 2508, Col. San Pedro Zacatenco,, 07360, Mexico City D.F., Mexico.
Environ Monit Assess. 2019 Jan 31;191(2):118. doi: 10.1007/s10661-019-7227-4.
The aim of this study was to know the biodiversity of total microorganisms contained in two polychlorinated biphenyl-contaminated aged soils and evaluate the strategies of bioaugmentation and biostimulation to biodegrade the biphenyls. Besides, the aerobic cultivable microorganisms were isolated and their capacity to biodegrade a commercial mixture of six congeners of biphenyls was evaluated. Biodiversity of contaminated soils was dominated by Actinobacteria (42.79%) and Firmicutes (42.32%) phyla, and others in smaller proportions such as Proteobacteria, Gemmatimonadetes, Chloroflexi, and Bacteroidetes. At the genus level, the majority of the population did not exceed 7% of relative abundance, including Bacillus, Achromobacter, Clostridium, and Pontibacter. Furthermore, four autochthonous bacterial cultures were possible isolates from the soils, which were identified by partial sequencing of the 16S rRNA gene, as Bacillus sp., Achromobacter sp., Pseudomonas stutzeri, and Bacillus subtilis, which were used for the bioaugmentation process. The bioaugmentation and biostimulation strategies achieved a biodegradation of about 60% of both soils after 8 weeks of the process; also, the four isolates were used as mixed culture to biodegrade a commercial mix of six polychlorinated biphenyl congeners; after 4 weeks of incubation, the concentration decreased from 0.5 mg/L to 0.23 mg/L.
本研究旨在了解两种多氯联苯污染老化土壤中总微生物的生物多样性，并评估生物强化和生物刺激策略以降解联苯。此外，还分离了好氧可培养微生物，并评估了它们降解六种商用联苯同系物混合物的能力。污染土壤的生物多样性主要由放线菌（42.79%）和厚壁菌门（42.32%）主导，其他如变形菌门、芽单胞菌门、绿弯菌门和拟杆菌门的比例较小。在属水平上，大多数种群的相对丰度不超过 7%，包括芽孢杆菌属、无色杆菌属、梭菌属和 Pontibacter 属。此外，从土壤中分离出了四个可能的土著细菌培养物，通过 16S rRNA 基因的部分测序鉴定为芽孢杆菌属、无色杆菌属、施氏假单胞菌和枯草芽孢杆菌，这些细菌被用于生物强化过程。生物强化和生物刺激策略在 8 周的时间内实现了两种土壤中约 60%的生物降解；此外，这四个分离株被用作混合培养物来降解六种商用多氯联苯同系物混合物；经过 4 周的培养，浓度从 0.5mg/L 降低到 0.23mg/L。
