Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005, Porto, Portugal.
Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005, Porto, Portugal.
Chemosphere. 2021 Jul;275:130037. doi: 10.1016/j.chemosphere.2021.130037. Epub 2021 Feb 24.
An increasing amount of industrial chemicals are being released into wastewater collection systems and indigenous microbial communities in treatment plants are not always effective for their removal. In this work, extracellular polymeric substances (EPS) recovered from aerobic granular sludge (AGS) were used as a natural carrier to immobilize a specific microbial strain, Rhodococcus sp. FP1, able to degrade 2-fluorophenol (2-FP). The produced EPS granules exhibited a 2-FP degrading ability of 100% in batch assays, retaining their original activity after up to 2-months storage. Furthermore, EPS granules were added to an AGS reactor intermittently fed with saline wastewater containing 2-FP. Degradation of 2-FP and stoichiometric fluorine release occurred 8 and 35 days after bioaugmentation, respectively. Chemical oxygen demand removal was not significantly impaired by 2-FP or salinity loads. Nutrients removal was impaired by 2-FP load, but after bioaugmentation, the phosphate and ammonium removal efficiency improved from 14 to 46% and from 25 to 42%, respectively. After 2-FP feeding ceased, at low/moderate salinity (0.6-6.0 g L NaCl), ammonium removal was completely restored, and phosphate removal efficiency increased. After bioaugmentation, 11 bacteria isolated from AGS were able to degrade 2-FP, indicating that horizontal gene transfer could have occurred in the reactor. The improvement of bioreactor performance after bioaugmentation with EPS immobilized bacteria and the maintenance of cell viability through storage are the main advantages of the use of this natural microbial carrier for bioaugmentation, which can benefit wastewater treatment processes.
越来越多的工业化学品被排放到废水收集系统中，而处理厂中的土著微生物群落并不总是能够有效地去除这些化学品。在这项工作中，从好氧颗粒污泥（AGS）中回收的胞外聚合物（EPS）被用作一种天然载体，来固定一种能够降解 2-氟苯酚（2-FP）的特定微生物菌株 Rhodococcus sp. FP1。所产生的 EPS 颗粒在批式实验中表现出 100%的 2-FP 降解能力，在长达 2 个月的储存后仍保留其原始活性。此外，EPS 颗粒被间歇添加到AGS 反应器中，该反应器连续进料含 2-FP 的盐水废水。生物强化后 8 天和 35 天分别发生 2-FP 降解和化学计量氟释放。2-FP 或盐度负荷对化学需氧量的去除没有显著影响。养分去除受到 2-FP 负荷的影响，但生物强化后，磷酸盐和铵盐的去除效率分别从 14%提高到 46%和从 25%提高到 42%。停止 2-FP 进料后，在低盐度（0.6-6.0 g/L NaCl）下，铵盐去除完全恢复，磷酸盐去除效率提高。生物强化后，从 AGS 中分离出的 11 种细菌能够降解 2-FP，表明在反应器中可能发生了水平基因转移。通过生物强化用 EPS 固定细菌来提高生物反应器的性能，以及通过储存来保持细胞活力，是使用这种天然微生物载体进行生物强化的主要优势，这可以使废水处理过程受益。
