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

Abstract

In this study, we evaluated the impact of the successive bioaugmentation of the activated sludge (AS) with the defined bacterial consortium on the activity and functional capacity of the AS microorganisms. In parallel, the removal of low concentrations of the selected non-steroidal anti-inflammatory drugs (ibuprofen, naproxen, diclofenac) and analgesic paracetamol was studied. We found that the addition of the bacterial consortium consisting of three pharmaceuticals-degrading strains Bacillus thuringiensis B1 (2015b), Stenotrophomonas maltophilia KB2, and Pseudomonas moorei KB4 into the AS did not cause any significant changes in the biomass abundance and metabolic activity of the AS microorganisms. Although, the successive bioaugmentation of the AS caused a slight increase in the metabolic diversity, the intensity of carbohydrates usage, and metabolic richness. Microorganisms in the bioaugmented and non-bioaugmented AS were able to degrade the mixture of the analyzed drugs with similar efficiency, however, diclofenac was removed more effectively in the bioaugmented AS. Several metabolites were identified and efficiently utilized, with the exception of 4-OH diclofenac. Two new diclofenac-degrading strains assigned as Serratia proteamaculans AS4 and Rahnella bruchi AS7 were isolated from the diclofenac-treated AS.

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

“…However, the presence of easily accessible carbon source, which serves as an electron-donating compound, may have also the opposite effect as demonstrated by Larcher et al [ 35 ] and Aissaoui et al [ 16 ]. A similar degraded dose was shown by Grandclément et al [ 14 ] for B. subtilis and B. laterosporus , which metabolized 1 mg L −1 of DCF in a nutrient broth medium during 17 h. In our previous work, we have isolated from DCF-treated activated sludge S. proteamaculans AS4 and R. bruchi AS7 strains, that were able to degrade nearly 0.5 mg L −1 of DCF within 14 days after 1.0 g L −1 of Glc addition [ 23 ]. Moreira et al [ 10 ] described complete degradation of DCF via co-metabolism at the concentration of 1.7 µM during 6 days and 34 µM during 25 days by L. portucalensis F11 strain.…”

“…The detection wavelength was set at 276 nm. DCF in the supernatant was identified by comparing the HPLC retention time and UV spectra with that of the external standard [ 23 ].…”

“…Mass spectrometer parameters were: nebulizing gas flow 3 L min −1 , drying gas flow 8 L min −1 , temperature 250 °C desolvation line, 400 °C heating block temperature. The analyses were performed in multiple reaction monitoring (MRM) mode [ 23 ]. For gas chromatography the samples were prepared according to Marchlewicz et al (2017).…”

“…The major bacterial taxa identified in the immobilized cell biofilter were Granulicella pectinivorans and Rhodanobacter terrae as well as the members of the species Castellaniella denitrificans , Parvibaculum lavamentivorans , Bordetella petrii , Bryocella elongata and Rhodopseudomonas palustris . We have previously described two novel strains isolated from DCF-treated activated sludge from Serratia and Rahnella genera [ 23 ]. So far, degradation of DCF has not been confirmed for any strain of Pseudomonas genus.…”

“…So far, degradation of DCF has not been confirmed for any strain of Pseudomonas genus. Despite the relatively large body of the literature about DCF degradation, mainly by activated sludge microflora [ 18 , 23 , 24 , 25 , 26 ], the genetic background of its decomposition remains scarce. Palyzová et al [ 20 ] reported about the presence of few genes related to DCF degradation encoding catechol 1,2-dioxygenase, protocatechuate 3,4-dioxygenase and quercetin 2,3-dioxygenase in Raoultella sp.…”