persists in sterile soils, indicating that soil microorganisms are responsible for its
rapid dissipation. This was confirmed by the isolation and characterization of several
fungal [156, 196–200] and bacterial strains able to degrade diclofenac as sole carbon
source [87, 97, 201] or through cometabolism [87, 93, 94, 196, 202–205].
Ecotoxicity of diclofenac on Gram-positive [206, 207] and Gram-negative bacteria [208, 209] was reported because of the inhibition of DNA synthesis [210] or of
the impairment of membrane activity [211, 212]. To date, only two studies have
assessed the effects of diclofenac on soil microorganisms [123, 160]. Experiments
performed by Cycon et al. [160] with different endpoints including substrateinduced respiration, soil enzyme activities, and enumeration of culturable bacteria
and fungi showed that diclofenac exposure led to an increase in the number of
culturable bacteria and fungi. At the highest dose (10 mg/kg), diclofenac increased
soil respiration as well as the activity of some soil enzymes (acid and alkaline
phosphatase, urease). On the contrary, it inhibited the activity of soil dehydrogenases, while it does not affect enzymatic activities (nitrification and ammonification)
of N cycle. Experiments performed by Thelusmond et al. [213] by means of Illumina
sequencing, STAMP and PiCRUST in agricultural soils observed an increase in
Proteobacteria, Gemmatimonadetes, and Actinobacteria and identified four metabolic pathways positively impacted (propanoate, lysine, fatty acid, and benzoate
metabolism) during diclofenac biodegradation.
3.2 Other Analgesics and Antipyretics: Paracetamol or
Acetaminophen
Paracetamol or acetaminophen is one of the most widely used over-the-counter
analgesic and antipyretic drug. The mechanism of action is complex and includes
the inhibition of the cyclooxygenase isozyme COX-3 involved in the synthesis of
prostaglandins and the activation of metabolites influencing cannabinoid receptors
[214, 215]. As result of its popular use, paracetamol has been frequently found in
wastewater treatment plants and in various environmental matrices all over the world
[147, 175, 216–227].
Paracetamol is transformed by both fungal [228, 229] and bacterial cultures
[96, 98, 99, 111, 230, 231]. In bacteria, two different biodegradation pathways via
hydroquinone [101, 111] or pyrocatechol [232] have been characterized [233]. To
date, only one study has addressed the fate of paracetamol in soil [39] showing that
17% of initial dose applied was mineralized in 120 days, while 73.4–93.3% was
recovered as non-extractable residues. Additionally, eight different transformation
products were identified, and new biodegradation pathways for paracetamol degradation in soil were proposed. In this study, paracetamol dissipation was mainly
explained by the rapid formation of bound residues preventing the dispersion of
paracetamol by leaching and/or runoff but accumulating in soil where it may
represent a risk for in soil living organisms.
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rapid dissipation. This was confirmed by the isolation and characterization of several
fungal [156, 196–200] and bacterial strains able to degrade diclofenac as sole carbon
source [87, 97, 201] or through cometabolism [87, 93, 94, 196, 202–205].
Ecotoxicity of diclofenac on Gram-positive [206, 207] and Gram-negative bacteria [208, 209] was reported because of the inhibition of DNA synthesis [210] or of
the impairment of membrane activity [211, 212]. To date, only two studies have
assessed the effects of diclofenac on soil microorganisms [123, 160]. Experiments
performed by Cycon et al. [160] with different endpoints including substrateinduced respiration, soil enzyme activities, and enumeration of culturable bacteria
and fungi showed that diclofenac exposure led to an increase in the number of
culturable bacteria and fungi. At the highest dose (10 mg/kg), diclofenac increased
soil respiration as well as the activity of some soil enzymes (acid and alkaline
phosphatase, urease). On the contrary, it inhibited the activity of soil dehydrogenases, while it does not affect enzymatic activities (nitrification and ammonification)
of N cycle. Experiments performed by Thelusmond et al. [213] by means of Illumina
sequencing, STAMP and PiCRUST in agricultural soils observed an increase in
Proteobacteria, Gemmatimonadetes, and Actinobacteria and identified four metabolic pathways positively impacted (propanoate, lysine, fatty acid, and benzoate
metabolism) during diclofenac biodegradation.
3.2 Other Analgesics and Antipyretics: Paracetamol or
Acetaminophen
Paracetamol or acetaminophen is one of the most widely used over-the-counter
analgesic and antipyretic drug. The mechanism of action is complex and includes
the inhibition of the cyclooxygenase isozyme COX-3 involved in the synthesis of
prostaglandins and the activation of metabolites influencing cannabinoid receptors
[214, 215]. As result of its popular use, paracetamol has been frequently found in
wastewater treatment plants and in various environmental matrices all over the world
[147, 175, 216–227].
Paracetamol is transformed by both fungal [228, 229] and bacterial cultures
[96, 98, 99, 111, 230, 231]. In bacteria, two different biodegradation pathways via
hydroquinone [101, 111] or pyrocatechol [232] have been characterized [233]. To
date, only one study has addressed the fate of paracetamol in soil [39] showing that
17% of initial dose applied was mineralized in 120 days, while 73.4–93.3% was
recovered as non-extractable residues. Additionally, eight different transformation
products were identified, and new biodegradation pathways for paracetamol degradation in soil were proposed. In this study, paracetamol dissipation was mainly
explained by the rapid formation of bound residues preventing the dispersion of
paracetamol by leaching and/or runoff but accumulating in soil where it may
represent a risk for in soil living organisms.
274
S. Gallego and F. Martin-Laurent