Effects of Low Concentration of Selected Analgesics and Successive Bioaugmentation of the Activated Sludge on Its Activity and Metabolic Diversity

Cultivable bacteria contribute to the removal of diclofenac and naproxen mix in a constructed wetland with Typha latifolia

Constructed wetlands are used to remove diclofenac and naproxen from wastewater. However, the role of plants and their root-associated bacteria in removing these pharmaceuticals is still unknown. In this work, bacteria were isolated from the roots of Typha latifolia cultivated in a constructed wetland to treat a diclofenac and naproxen mix. 16S rDNA sequencing indicated that bacterial isolates belong to the Pseudomonas, Serratia, and Rahnella genera. All bacterial isolates showed tolerance to high concentrations of diclofenac and naproxen and had differential laccase activity, phosphate-solubilizing activity, and indole acetic acid production.Bacteria were grouped into three consortia A (0-30 cm), B (50-80 cm), and C (100-130 cm), according to the site from which they were isolated in the wetland. Plant-bacteria interaction assays were conducted to determine the removal capacity of diclofenac and naproxen mix by the bacterial consortia or their interaction with T. latifolia. The results showed that all bacterial consortia removed over 50% of diclofenac and naproxen, while in their interaction with T. latifolia the removal capacity increased to over 70%. Consortium B was the most efficient in removing diclofenac and naproxen, with removal rates of 63.85 ± 0.45% and 74.93 ± 0.75%, respectively. Meanwhile, in the interaction of consortium B with T. latifolia, the removal of diclofenac and naproxen increased to 82.27 ± 0.30% and 88.12 ± 1.23%, respectively. Overall, the results indicated that T. latifolia and its root-associated bacteria removed the diclofenac and naproxen mix in the constructed wetland, contributing to understanding the role of the plant and bacteria in removing emerging contaminants. Therefore, the interaction of T. latifolia and its root-associated bacteria could potentially be used in strategies to remove emerging contaminants from wastewater.

Decomposition of non-steroidal anti-inflammatory drugs by activated sludge supported by biopreparation in sequencing batch reactor

The presence of non-steroidal anti-inflammatory drugs in wastewater from sewage treatment plants indicates that they are not completely biodegradable. The designed biopreparation based on immobilized bacteria enables the degradation of paracetamol, ibuprofen, naproxen and diclofenac at a rate of 0.50 mg/L*day, 0.14 mg/L*day, 0.16 mg/L*day and 0.04 mg/L*day, respectively. Lower degradation of drugs in the mixture than in monosubstrate systems indicates their additive, antagonistic effect, limiting the degradative capacity of microorganisms. The biopreparation is stable for at least 6 weeks in bioreactor conditions. Biochemical parameters of activated sludge functioning showed increased oxygen demand, which was related to increased ammonia concentration caused by long-term exposure of activated sludge to drugs. Reduced metabolic activity was also observed. The preparation enables decomposing drugs and their metabolites, restoring the activated sludge's functionality. The tested biopreparation can support activated sludge in sewage treatment plants in degrading non-steroidal anti-inflammatory drugs and phenolic compounds.

The microbial removal of bisphenols in aquatic microcosms and associated alteration in bacterial community

The concept of the study resulted from numerous concerns around bisphenol A (BPA) and bisphenol S (BPS) in aquatic environments. In this study, river water and sediment microcosms highly polluted with bisphenols and bioaugmented with two BPs-removing bacterial strains were constructed. The study aimed to determine the rate of high-concentrated BPA and BPS (BPs) removal from river water and sediment microniches, and the effect of water bioaugmentation with bacterial consortium on the removal rates of these pollutants. Moreover, the impact of introduced strains and exposure to BPs on the structural and functional composition of the autochthonous bacterial communities was elucidated. Our findings indicate that the removal activity of autochthonous bacteria was sufficient for effectively BPA elimination and reducing BPS content in the microcosms. The number of introduced bacterial cells decreased continuously until day 40, and on consecutive sampling days, no bioaugmented cells were detected. Sequencing analysis of the total 16S rRNA genes revealed that the community composition in bioaugmented microcosms amended with BPs differed significantly from those treated either with bacteria or BPs. A metagenomic analysis found an increase in the abundance of proteins responsible for xenobiotics removal in BPs-amended microcosms. This study provides new insights into the effects of bioaugmentation with a bacterial consortium on bacterial diversity and BPs removal in aquatic environments.

Evaluation of the Defined Bacterial Consortium Efficacy in the Biodegradation of NSAIDs

Due to the increasing pollution of wastewater with non-steroidal anti-inflammatory drugs, preparations need to be developed to decompose these drugs. This work aimed to develop a bacterial consortium with a defined composition and boundary conditions for the degradation of paracetamol and selected non-steroidal anti-inflammatory drugs (NSAIDs), including ibuprofen, naproxen, and diclofenac. The defined bacterial consortium consisted of Bacillus thuringiensis B1(2015b) and Pseudomonas moorei KB4 strains in a ratio of 1:2. During the tests, it was shown that the bacterial consortium worked in the pH range from 5.5 to 9 and temperatures of 15-35 °C, and its great advantage was its resistance to toxic compounds present in sewage, such as organic solvents, phenols, and metal ions. The degradation tests showed that, in the presence of the defined bacterial consortium in the sequencing batch reactor (SBR), drug degradation occurred at rates of 4.88, 10, 0.1, and 0.05 mg/day for ibuprofen, paracetamol, naproxen, and diclofenac, respectively. In addition, the presence of the tested strains was demonstrated during the experiment as well as after its completion. Therefore, the advantage of the described bacterial consortium is its resistance to the antagonistic effects of the activated sludge microbiome, which will enable it to be tested in real activated sludge conditions.

Orange peel-derived Cu2O/RGO nanocomposite: Mesoporous binary system for degradation of doxycycline in water

In recent times, there is a mammoth challenge for the world and mankind to deal with the frequent use and misuse of antibiotics and its casual discard to the water bodies. The scavenging degradation of antibiotics which are no longer in use from the environment is a growing concern and compulsively needs to be addressed. Herein, we have devised a novel and green protocol for the synthesis of Cu2O decorated on reduced graphene oxide (Cu2O/RGO) nanocomposite (NCs) using agro-waste, i.e., orange pomace extract (OPE) as a reducing and stabilizing agent for the degradation of antibiotic. The biogenically synthesized Cu2O/RGO NCs proved to emerge as an excellent degradation catalyst exhibiting efficiency of 98.68% within 15 min and 86.38% within 30 min for 10 mg/L DC concentration assisted by ultrasound waves and solar light respectively in separate reactions. The complete degradation process followed a pseudo-first-order kinetics with a rate constant of 0.29 min- 1 and 0.0542 min- 1 for sonocatalytic and photocatalytic degradation process, respectively. Surface area analysis showed that with the increase in the GO amount, the doxycycline degradation increases. An in-depth mechanistic account of sonocatalytic and photocatalytic process has been discussed followed by a radical scavenging test which validated the major role of the synthesized NCs in the degradation of DC. The extraordinary catalytic indulgence of biogenically synthesized graphene-based nanocatalyst opens newer avenues for future research in green chemistry and catalytic field.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10668-022-02895-2.

Effluent decontamination by the ibuprofen-mineralizing strain, Sphingopyxis granuli RW412: Metabolic processes

The high global consumption of ibuprofen and its limited elimination by wastewater treatment plants (WWTPs), has led to the contamination of aquatic systems by this common analgesic and its metabolites. The potentially negative environmental and public health effects of this emerging contaminant have raised concerns, driving the demand for treatment technologies. The implementation of bacteria which mineralize organic contaminants in biopurification systems used to decontaminate water or directly in processes in WWTPs, is a cheap and sustainable means for complete elimination before release into the environment. In this work, an ibuprofen-mineralizing bacterial strain isolated from sediments of the River Elbe was characterized and assayed to remediate different ibuprofen-polluted media. Strain RW412, which was identified as Sphingopyxis granuli, has a 4.48 Mb genome which includes plasmid sequences which harbor the ipf genes that encode the first steps of ibuprofen mineralization. Here, we confirm that these genes encode enzymes which initiate CoA ligation to ibuprofen, followed by aromatic ring activation by a dioxygenase and retroaldol cleavage to unequivocally produce 4-isobutylcatechol and propionyl-CoA which then undergo further degradation. In liquid mineral salts medium, the strain eliminated more than 2 mM ibuprofen within 74 h with a generation time of 16 h. Upon inoculation into biopurification systems, it eliminated repeated doses of ibuprofen within a few days. Furthermore, in these systems the presence of RW412 avoided the accumulation of ibuprofen metabolites. In ibuprofen-spiked effluent from a municipal WWTP, ibuprofen removal by this strain was 7 times faster than by the indigenous microbiota. These results suggest that this strain can persist and remain active under environmentally relevant conditions, and may be a useful innovation to eliminate this emerging contaminant from urban wastewater treatment systems.

Degradation of diclofenac by new bacterial strains and its influence on the physiological status of cells

Diclofenac (DCF) is one of the most commonly utilized non-steroidal anti-inflammatory drugs (NSAIDs), which is known to pose an ecotoxicological threat. In this study, from activated sludge and contaminated soil, we isolated four new bacterial strains able to degrade DCF under mono-substrate and co-metabolic conditions with glucose supplementation. We found that the effectiveness of DCF removal is strictly strain-specific and the addition of the primary substrate is not always beneficial. To assess the multidirectional influence of DCF on bacterial cells we evaluated the alterations of increasing concentrations of this drug on membrane structure. A significant increase was observed in the content of 17:0 cyclo fatty acid, which is responsible for reduced fluidity and profound changes in membrane rigidity. The cell injury and oxidative stress were assessed with biomarkers used as endpoints of toxicity, i.e. catalase (CAT), superoxide dismutase (SOD), lipids peroxidation (LPX), and both intra- and extracellular alkaline and acid phosphatase activity. Results indicated that DCF induced oxidative stress, frequently intensified by the addition of glucose. However, the response of the microbial cells to the presence of DCF should not be generalized, since the overall picture of the particular alterations greatly varied for each of the examined strains.

Graphene-Based Composites as Catalysts for the Degradation of Pharmaceuticals

The incessant release of pharmaceuticals into the aquatic environment continues to be a subject of increasing concern. This is because of the growing demand for potable water sources and the potential health hazards which these pollutants pose to aquatic animals and humans. The inability of conventional water treatment systems to remove these compounds creates the need for new treatment systems in order to deal with these class of compounds. This review focuses on advanced oxidation processes that employ graphene-based composites as catalysts for the degradation of pharmaceuticals. These composites have been identified to possess enhanced catalytic activity due to increased surface area and reduced charge carrier recombination. The techniques employed in synthesizing these composites have been explored and five different advanced oxidation processes-direct degradation process, chemical oxidation process, photocatalysis, electrocatalyis processes and sonocatalytic/sono-photocatalytic processes-have been studied in terms of their enhanced catalytic activity. Finally, a comparative analysis of the processes that employ graphene-based composites was done in terms of process efficiency, reaction rate, mineralization efficiency and time required to achieve 90% degradation.

Diclofenac Degradation-Enzymes, Genetic Background and Cellular Alterations Triggered in Diclofenac-Metabolizing Strain Pseudomonas moorei KB4

Diclofenac (DCF) constitutes one of the most significant ecopollutants detected in various environmental matrices. Biological clean-up technologies that rely on xenobiotics-degrading microorganisms are considered as a valuable alternative for chemical oxidation methods. Up to now, the knowledge about DCF multi-level influence on bacterial cells is fragmentary. In this study, we evaluate the degradation potential and impact of DCF on Pseudomonas moorei KB4 strain. In mono-substrate culture KB4 metabolized 0.5 mg L⁻¹ of DCF, but supplementation with glucose (Glc) and sodium acetate (SA) increased degraded doses up to 1 mg L⁻¹ within 12 days. For all established conditions, 4′-OH-DCF and DCF-lactam were identified. Gene expression analysis revealed the up-regulation of selected genes encoding biotransformation enzymes in the presence of DCF, in both mono-substrate and co-metabolic conditions. The multifactorial analysis of KB4 cell exposure to DCF showed a decrease in the zeta-potential with a simultaneous increase in the cell wall hydrophobicity. Magnified membrane permeability was coupled with the significant increase in the branched (19:0 anteiso) and cyclopropane (17:0 cyclo) fatty acid accompanied with reduced amounts of unsaturated ones. DCF injures the cells which is expressed by raised activities of acid and alkaline phosphatases as well as formation of lipids peroxidation products (LPX). The elevated activity of superoxide dismutase (SOD) and catalase (CAT) testified that DCF induced oxidative stress.