Biodegradation of PCBs in contaminated water using spent oyster mushroom substrate and a trickle-bed bioreactor

0524386 - MBÚ 2021 RIV GB eng J - Journal Article
Šrédlová, Kamila - Škrob, Zdena - Filipová, Alena - Mašín, P. - Holecová, Jana - Cajthaml, Tomáš
Biodegradation of PCBs in contaminated water using spent oyster mushroom substrate and a trickle-bed bioreactor.
Water Research. Roč. 170, March 1 (2020), č. článku 115274. ISSN 0043-1354. E-ISSN 1879-2448
R&D Projects: GA TA ČR TE01020218
Institutional support: RVO:61388971
Keywords : Polychlorinated biphenyls * Bioremediation * Pleurotus ostreatus
OECD category: Environmental biotechnology
Impact factor: 11.236, year: 2020
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0043135419310486

Due to their persistence, polychlorinated biphenyls (PCBs) represent a group of important environmental pollutants, but conventional physicochemical decontamination techniques for their removal are usually expensive. The main aim of this work was to develop a cost-effective method for PCB bioremediation, focusing on contaminated water and utilizing the well-known degradation capability of Pleurotus ostreatus (the oyster mushroom). For this purpose, the conditions of several laboratory-scale reactors (working volume 1 L) were optimized. Spent oyster mushroom substrate obtained from a commercial farm was used as a fungal inoculum and growth substrate. The highest degradation efficiency (87%) was recorded with a continuous low-flow setup, which was subsequently scaled up (working volume 500 L) and used for the treatment of 4000 L of real contaminated groundwater containing 0.1-1 mu g/L of PCBs. This trickle-bed pilot-scale bioreactor was able to remove 82, 80, 65, and 30-50% of di-, tri-, tetra- and pentachlorinated PCB congeners, respectively. No degradation was observed for hexa- or heptachlorinated congeners. Multiple mono- and dichlorobenzoic acids (CBAs) were identified as transformation products by mass spectrometry, confirming the role of biodegradation in PCB removal. A Vibrio fischeri bioluminescence inhibition test revealed slight ecotoxicity of the primary reactor effluent (sampling after 24 h), which was quickly suppressed once the effluent passed through the reactor for the second time. Moreover, no other effluent exhibited toxicity for the rest of the experiment (71 days in total). Microbial analyses (phospholipid fatty acid analysis and next-generation sequencing) showed that P. ostreatus was able to degrade PCBs in the presence of an abundance of other fungal species as well as aerobic and anaerobic bacteria.
Permanent Link: http://hdl.handle.net/11104/0308738