Fluoroquinolone (FQ) antibiotics are extensively used both in human and veterinary medicine, and their accumulation in the environment is causing an increasing concern. In this study, the ...biodegradation of the three most worldwide used FQs, namely ofloxacin, norfloxacin, and ciprofloxacin, by the fluoroorganic-degrading strain Labrys portucalensis F11 was assessed. Degradation occurred when the FQs were supplied individually or as mixture in the culture medium, in the presence of an easily degradable carbon source. Consumption of individual FQs was achieved at different extents depending on its initial concentration, ranging from 0.8 to 30 μM. For the lowest concentration, total uptake of each FQ was observed but stoichiometric fluoride release was not achieved. Intermediate compounds were detected and identified by LC-MS/MS with a quadrupole time of flight detector analyzer. Biotransformation of FQs by L. portucalensis mainly occurred through a cleavage of the piperazine ring and displacement of the fluorine substituent allowing the formation of intermediates with less antibacterial potency. FQ-degrading microorganisms could be useful for application in bioaugmentation processes towards more efficient removal of contaminants in wastewater treatment plants.
Treatment of tannery wastewater is problematic due to high and variable concentrations of complex pollutants often combined with high salinity levels. Two series of horizontal subsurface flow ...constructed wetlands (CWs) planted with
Arundo donax and
Sarcocornia fruticosa were set up after a conventional biological treatment system operating at a tannery site. The aim of the CWs was polishing organics and nitrogen from the high salinity effluent (2.2–6.6 g Cl
− L
−1). Both plant species established and grew well in the CW.
Arundo, however, had more vigorous growth and a higher capacity to take up nutrients. The CWs were efficient in removing COD and BOD
5 with removal efficiencies varying between 51 and 80% for COD (inlet: 68–425 mg L
−1) and between 53 and 90% for BOD
5 (inlet: 16–220 mg L
−1). Mass removal rates were up to 615 kg COD ha
−1 d
−1 and 363 BOD
5 kg ha
−1 d
−1. Removal efficiencies were 40–93% for total P, 31–89% for NH
4
+ and 41–90% for Total Kjeldahl Nitrogen. CW systems planted with salt tolerant plant species are a promising solution for polishing saline secondary effluent from the tannery industry to levels fulfilling the discharge standards.
► High salinity tannery wastewater can successfully be treated in constructed wetlands. ►
Arundo and
Sarcocornia tolerate high salinity tannery wastewater. ► Removal efficiencies of up to 80% for COD (inlet: 68–425 mg L
−1) were achieved. ► The effluent coming from the constructed wetlands fulfilled the discharge standards. ► For operational flexibility CW should be established with beds in series.
•The multi-techniques analytical approach allowed the evaluation of the degradation of fluoroquinolones by a microbial consortium.•Fluoride ions released exposed the incomplete mineralization of the ...fluoroquinolones.•Metabolites were identified by LC–MS/MS and QqTOF MS.•New structures of the intermediates were proposed.
Antibiotics are a therapeutic class widely found in environmental matrices and extensively studied due to its persistence and implications for multi-resistant bacteria development. This work presents an integrated approach of analytical multi-techniques on assessing biodegradation of fluorinated antibiotics at a laboratory-scale microcosmos to follow removal and formation of intermediate compounds. Degradation of four fluoroquinolone antibiotics, namely Ofloxacin (OFL), Norfloxacin (NOR), Ciprofloxacin (CPF) and Moxifloxacin (MOX), at 10mgL−1 using a mixed bacterial culture, was assessed for 60 days. The assays were followed by a developed and validated analytical method of LC with fluorescence detection (LC–FD) using a Luna Pentafluorophenyl (2) 3μm column. The validated method demonstrated good selectivity, linearity (r2>0.999), intra-day and inter-day precisions (RSD<2.74%) and accuracy. The quantification limits were 5μgL−1 for OFL, NOR and CPF and 20μgL−1 for MOX. The optimized conditions allowed picturing metabolites/transformation products formation and accumulation during the process, stating an incomplete mineralization, also shown by fluoride release. OFL and MOX presented the highest (98.3%) and the lowest (80.5%) extent of degradation after 19 days of assay, respectively. A representative number of samples was selected and analyzed by LC–MS/MS with triple quadrupole and the molecular formulas were confirmed by a quadruple time of flight analyzer (QqTOF). Most of the intermediates were already described as biodegradation and/or photodegradation products in different conditions; however unknown metabolites were also identified. The microbial consortium, even when exposed to high levels of FQ, presented high percentages of degradation, never reported before for these compounds.
Antibiotics are the most consumed therapeutic classes worldwide and are released to the environment in their original form as well as potentially active metabolites and/or degradation products. ...Consequences of the occurrence of these compounds in the environment are primarily related to bacterial resistance development.
This work presents a validated analytical method based on solid phase extraction (SPE) using HLB cartridges, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for quantification of seven different fluoroquinolone antibiotics, namely ciprofloxacin (CPF), enrofloxacin (ENR), lomefloxacin (LOM), norfloxacin (NOR), ofloxacin (OFL), prulifloxacin (PLF) and moxifloxacin (MOX) and its application to detect the target compounds in influents and effluents of wastewater treatment plants (WWTP). Linearity was established through calibration curves in solvent and matrix match using internal calibration method in the range of 50–1300 ng L−1 and all the fluoroquinolones showed good linear fit (r2 ≥ 0.991). Accuracy ranged between 80.3 and 92.9%, precision was comprised between 7.2 and 14.6%, and 10.7 and 18.1% for intra- and inter-batch determinations, respectively. Method detection and quantification limits ranged from 6.7 to 59.0 ng L−1 and 22.3–196.6 ng L−1, respectively.
Influents and effluents of fifteen WWTPs of North of Portugal were analyzed. OFL was the fluoroquinolone found at the highest concentration, up to 4587.0 ng L−1 and 987.9 ng L−1, in influent and effluent, respectively. NOR and PLF were not detected.
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•FQs were analyzed in thirty WWTP samples (influent and effluent) from fifteen WWTPs.•High concentration of ciprofloxacin and ofloxacin was found in WWTP influents.•Ofloxacin was quantified in most of all WWTP effluents.•Important information about FQs in WWTP with different removal systems.
The present works characterizes WWTP influents and effluents regarding seven different fluoroquinolone antibiotics in fifteen Portuguese northern WWTPs with diverse operational features and treatment procedures.
A granular sludge sequencing batch reactor (SBR) was operated for 340 days for treating a synthetic wastewater containing fluoroquinolones (FQs), namely ofloxacin, norfloxacin and ciprofloxacin. The ...SBR was intermittently fed with FQs, at concentrations of 9 and 32 μM. No evidence of FQ biodegradation was observed but the pharmaceutical compounds adsorbed to the aerobic granular sludge, being gradually released into the medium in successive cycles after stopping the FQ feeding.
Overall COD removal was not affected during the shock loadings. Activity of ammonia oxidizing bacteria and nitrite oxidizing bacteria did not seem to be inhibited by the presence of FQs (maximum of 0.03 and 0.01 mM for ammonium and nitrite in the effluent, respectively). However, during the FQs feeding, nitrate accumulation up to 1.7 mM was observed at the effluent suggesting that denitrification was inhibited. The activity of phosphate accumulating organisms was affected, as indicated by the decrease of P removal capacity during the aerobic phase. Exposure to the FQs also promoted disintegration of the granules leading to an increase of the effluent solid content, nevertheless the solid content at the bioreactor effluent returned to normal levels within ca. 1 month after removing the FQs in the feed allowing recovery of the bedvolume. Denaturing gradient gel electrophoresis revealed a dynamic bacterial community with gradual changes due to FQs exposure. Bacterial isolates retrieved from the granules predominantly belonged to α- and γ-branch of the Proteobacteria phylum.
The capacity of the system to return to its initial conditions after withdrawal of the FQ compounds in the inlet stream, reinforced its robustness to deal with wastewaters containing organic pollutants.
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•Effect of ofloxacin, norfloxacin and ciprofloxacin on aerobic granules was studied.•Fluoroquinolones adsorbed reversibly onto granular sludge, no biodegradation occurred.•Prolonged fluoroquinolones feeding led to nitrate accumulation in the SBR effluent.•Exposure to fluoroquinolones destabilized the granules.•Granules quickly recovered after withdrawing fluoroquinolones from influent.
•Zea mays plants were inoculated with phosphate solubilizing bacteria (PSB).•P-deficiency in soils negatively influenced Z. mays growth.•Inoculation of PSB promoted Z. mays biomass production in ...P-deficient soils.•PSB were able to colonize rhizosphere soils of the Z. mays plants.•These PSB can be used as biofertlizers in P-deficient soils.
This work aimed to evaluate the ability of phosphate-solubilizing bacteria (PSB) to enhance Zea mays growth in an agricultural P-deficient soil. Five strains were screened for their ability to solubilize P and to produce plant growth promoting (PGP) substances. The best P-solubilizing strains Rhodococcus sp. EC35 (B1), Pseudomonas sp. EAV (B2) and Arthrobacter nicotinovorans EAPAA (B3) were inoculated in maize plants growing in P-deficient soils without P fertilization and amended with soluble (KH2PO4) and with tricalcium phosphate (TCP). The inoculated PSB were monitored in soil by DGGE. PSB enhanced maize biomass production in all P-treatments. In soils without P fertilization, bacterial inoculation increased P concentration in roots and shoots and plant dry biomass (ca. 20%). In soils amended with soluble P, strain B2 was the bacteria that better performed improving root and shoot biomass by 102% and 63%, respectively. In soils amended with TCP, plant biomass was also enhanced by bacterial inoculation as well as P accumulation in plant tissues (B3 and BM – mixed inoculation). Plant growth enhancement seems to be related not only to P solubilization but also to other PGP traits, like indol-3-acetic acid and ACC-deaminase activity. DGGE profiles allowed to confirm the presence of PSB in maize rhizosphere after 45 days. This work clearly indicates that inoculated PSB have great potential to be used as biofertilizers in P-deficient soils, especially strains Pseudomonas sp. EAV and A. nicotinovorans EAPAA since both highly increased P availability in soils and promoted maize growth, constituting an attractive alternative to the phosphatic fertilizers amendments.
Zea mays, one of the most important cereals worldwide, is a plant not only with food and energy value, but also with phytoremediation potential. The use of plant growth promoting (PGP) rhizobacteria ...may constitute a biological alternative to increase crop yield and plant resistance to degraded environments. In search for PGP rhizobacteria strains, 6 bacterial isolates were isolated from a metal contaminated site, screened
in vitro for their PGP characteristics and their effects on the growth of
Z. mays were assessed. Isolates were identified as 3A10
T, ECP37
T, corresponding to
Chryseobacterium palustre and
Chryseobacterium humi, and 1ZP4, EC15, EC30 and 1C2, corresponding to strains within the genera
Sphingobacterium,
Bacillus,
Achromobacter, and
Ralstonia, respectively. All the bacterial isolates were shown to produce indole acetic acid, hydrogen cyanide and ammonia when tested
in vitro for their plant growth promoting abilities, but only isolates 1C2, 1ZP4 and ECP37
T have shown siderophore production. Their further application in a greenhouse experiment using
Z. mays indicated that plant traits such as root and shoot elongation and biomass production, and nutrient status, namely N and P levels, were influenced by the inoculation, with plants inoculated with 1C2 generally outperforming the other treatments. Two other bacterial isolates, 1ZP4 and ECP37
T also led to increased plant growth in the greenhouse. These 3 species, corresponding to strains within the genera
Ralstonia (1C2),
Sphingobacterium (1ZP4), and to a strain identified as
C. humi (ECP37
T) can thus be potential agents to increase crop yield in maize plants.
The wide chemical and biological diversity observed in the marine environment makes the ocean an extraordinary source of high added value compounds (HAVC) which can be employed in many applications. ...Minerals, lipids, amino acids, polysaccharides and proteins from marine sources have unique features and, surprisingly, their highest concentration is often found in parts of marine organisms that are commonly discarded. Fish heads, viscera, skin, tails, offal and blood, as well as seafood shells possess several HAVC suitable for human health applications, yet most end up as residues throughout the raw material processing.
This review updates information on this issue and conveys critical analysis of the chief methodologies to carry out extraction, purification and eventual transformation, with a focus on their actual and potential applications.
Wastewaters from leather processing are very complex and lead to water pollution if discharged untreated, especially due to its high organic loading. In this study the survival of different plant ...species in subsurface horizontal flow constructed wetlands receiving tannery wastewater was investigated. Five pilot units were vegetated with
Canna indica,
Typha latifolia,
Phragmites australis,
Stenotaphrum secundatum and
Iris pseudacorus, and a sixth unit was left as an unvegetated control. The treatment performance of the systems under two different hydraulic loading rates, 3 and 6
cm
d
−1, was assessed. COD was reduced by 41–73% for an inlet organic loading varying between 332 and 1602
kg
ha
−1
d
−1 and BOD
5 was reduced by 41–58% for an inlet organic loading varying between 218 and 780
kg
ha
−1
d
−1. Nutrient removal occurred to lower extents.
Phragmites australis and
Typha latifolia were the only plants that were able to establish successfully. Despite the high removal of organic content from the influent wastewater, during 17 months of operation, no significant differences in performance were observed between units.
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