Chlortetracycline (CTC) usually presents in livestock wastewater with oxytetracycline (OTC), causing damage to human health and ecosystems. It’s urgent to seek low-cost and ecofriendly technology for ...antibiotics removal. In this study, effects of CTC and CTC + OTC (CTC:OTC= 1:1, g/g) on Spirulina platensis have been investigated. EC50 value of CTC for S. platensis was 8.76 mg/L at 96 h and risk quotient value in wastewater was 15.85. Inhibition of CTC on S. platensis gradually enhanced with increase of CTC, but CTC + OTC below 1.0 mg/L didn’t harm the growth of microalgae. Chlorophyll-a (Chl-a) and carotenoid content showed a parabolic trend with extension of time at CTC group. Chl-a synthesis gradually decreased with increase of CTC + OTC stress. High concentrations of CTC and CTC + OTC showed obvious inhibition on phycocyanin production. Polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFA) contents peaked at 1.0 mg/L CTC, corresponding to the minimum of superoxide dismutase (SOD) activity in S. platensis. SFA and PUFA contents decreased when CTC + OTC content was above 2.0 mg/L. CTC and CTC + OTC (both over 2.0 mg/L) stimulated production of dissolved extracellular organic matters in S. platensis. Removal efficiency of CTC by S. platensis was about 98.63–99.95% and its biodegradation pathways were hydroxylation and side-chain breakdown.
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•Half maximal effective concentration for Spirulina platensis was 8.76 mg/L at 96 h.•Risk quotient value indicated CTC had high risk to S. platensis in wastewater.•Inhibition rate of CTC on S. platensis was more than that of CTC + oxytetracycline.•High CTC improved yield of dissolved extracellular organic matters in S. platensis.•Hydroxylation and side-chain breakdown were the main biodegradation pathways of CTC.
The production of commercial livestock and poultry often involves using with antibiotics and feed additives, such as oxytetracycline (OTC) and copper (Cu). These are often excreted into the soil by ...animal feces; hence, combined pollutants may contaminate the soil. To evaluate single and combined toxic effects of OTC and Cu on the soil ecology, changes in quantities of bacteria, fungi, and actinomycetes in the soil were studied over a 28-d incubation period by a plate count method, microbes numbers counted on days 7, 14, 21, and 28. Abundances of ammonia monooxygenase (
amoA
) gene expression by ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in soil samples also were tested by real-time polymerase chain reactions (RT-PCRs) on day 21. The results revealed that the numbers of bacteria, fungi and actinomycetes and
amoA
genes copies of AOA and AOB were reduced seriously by exposure to Cu (1.60 mmol/kg). Similarly, the combined pollution treatments (mole ratios of OTC: Cu was 1:2, 1:8, and 1:32) also had inhibitory effect on bacteria, fungi, and actinomycetes numbers and
amoA
gene copies of AOA and AOB; the inhibitory rate was on obvious growth trend with the increasing mole ratios. Effects from single OTC pollution were found on bacteria (days 7 and 14), fungi (days 7, 14, 21, and 28), and AOA-
amoA
gene copies (day 21), with promotion at a low concentration (0.05 mmol/kg) and suppression at higher concentrations (0.2 and 0.8 mmol/kg). Also, numbers of bacteria, fungi, and actinomycetes decreased with longer culture times. Combining OTC and Cu led to a higher inhibition of soil microbes than when either chemical was used alone. However, there was no significant relationship between single and combined toxic chemicals because of their complicated interactions, either antagonistic or synergistic. The results also indicated the sensitivity of bacteria, fungi, actinomycetes on toxic chemicals existed difference and that the AOA were more tolerant than the AOB to these chemicals.
In this work a kinetic fluorometric methodology relying on the time-based monitoring of the photoluminescence quenching of AgInS2 ternary quantum dots induced by oxytetracycline, was developed. The ...kinetic approach allowed not only to reduce the LOD and improve sensitivity and selectivity but also to collect second-order data that was explored for the quantification of the target analyte in the presence of uncalibrated interfering species.
Upon processing the acquired second-order kinetic PL data by unfolded partial least-squares (U-PLS), oxytetracycline was quantified in commercially available pharmaceutical formulations. The obtained results, namely an R2P higher than 0.99 and RE lower than 8%, proved the suitability and accuracy of the developed approach.
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•The kinetic behavior of the PL quenching of AIS QDs in the presence of OTC was studied.•Chemometric methods were implemented to improve the performance of the OTC kinetic determination.•U-PLS/RBL was applied to obtain second-order advantage circumventing selectivity issues.•Kinetic approach resorting to chemometric tools allowed to reduce the LOD with enhanced sensitivity.•The developed methodology was successfully applied in OTC monitoring in pharmaceutical formulations.
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•The pH affected the destruction of OTC by UV-C only and UV-C/H2O2 AOP.•Second-order rate constant of OTC with HO increased with increasing pH.•The presence of carbonate/bicarbonate ...enhanced the removal of OTC by UV/H2O2.•The effective role of CO3− for the degradation of OTC was confirmed.•Second-order rate constant of OTC with CO3− was estimated to be 2.9×108M−1s−1.
In this study, the influence of pH on the degradation of oxytetracycline (OTC) by UV-C only and UV-C/H2O2 advanced oxidation process (AOP) was investigated. The effect of carbonate and bicarbonate on the photochemical transformation of OTC in UV/H2O2 system was also evaluated. It was found that, by UV irradiation alone, the degradation of OTC was significantly improved with increasing pH; while in UV/H2O2 system, the observed UV fluence based pseudo first-order rate constant of OTC was found to be the highest at pH 5.5 and comparable at neutral and basic pH conditions. The conversion of OTC by UV/H2O2 was not inhibited in the presence of carbonate or bicarbonate. Instead, a slight promotion was observed at high concentrations of carbonate or bicarbonate. The presence of carbonate radical in UV/H2O2/Na2CO3 and UV/H2O2/NaHCO3 systems was demonstrated by adding three different alcohols, i.e., tert-butanol (t-BuOH), methanol (MeOH), and isopropanol (i-PrOH) that barely react with carbonate radical, and by adding 4-chlorophenol (4-CP) which has a high second-order rate constant with carbonate radical. The second-order rate constant of OTC with carbonate radical was subsequently determined. The results indicate that carbonate radical can play an important role on the degradation of organic compounds such as OTC in UV/H2O2 system in the presence of carbonate or bicarbonate that is commonly found in natural environment.
Little is known about the effects of oxytetracycline (OTC) on marine fish. Using juvenile pearl gentian grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂), we investigated the effects of 56 days ...dietary oxytetracycline (OTC; OTCD) exposure (80 mg/kg body weight/day) on fish growth performance, intestinal health and antibiotic residue. Meanwhile, the alteration of intestinal health status and antibiotic residue after 7 (O7) or 14 days (O14) OTC withdrawal treatment were explored. We also assessed the potential human health risks based on target hazard quotient (THQ). The results showed that OTC exposure had no effects on growth rate parameters but caused liver and intestine atrophy. OTC exposure impaired the intestinal health by distorting intestinal morphological features, inducing oxidative stress, repressing immune function, triggering NF-κB-mediated inflammatory response and apoptosis, while 7 days OTC withdrawal treatment improved intestinal health status and 14 days OTC withdrawal treatment further improved it. In addition, the order of OTC residue in tested tissues after OTC exposure was: liver > kidney > spleen > muscle > intestine. OTC residue was significantly decreased in all tissues along with the increasing of withdrawal treatment period. Adults and children consuming the edible tissues (muscle) of OTC-treated or withdrawal-treated pearl gentian grouper would not experience any previous health risk as the THQ < 1 in all group.
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•Dietary oxytetracycline (OTC) impaired intestinal health of pearl gentian grouper.•Dietary OTC triggered NF-κB signaling pathway in pearl gentian grouper.•OTC residue was the highest in the liver of pearl gentian grouper.•Withdrawal treatment attenuated the side effects induced by OTC exposure.
In this study, novel MnO2/UIO-66 composite material was constructed via oil bath heating. MnO2 was prepared from KMnO4 and UIO-66 was prepared from C8H6O4 and ZrCl4. The MnO2/UIO-66 activated ...peroxymonosulfate (PMS) with high efficiency for oxytetracycline (OTC) decomposition under UV-light which was much more effective than adding MnO2/UIO-66 without PMS. Characterization analysis was carried out by means of XRD, SEM, TEM and XPS, etc. The effects of reaction system and catalyst addition on the degradation of OTC were also studied. Degradation of OTC with MnO2, UIO-66 and MnO2/UIO-66 was inhibited in the H2O2 system and promoted in the PMS and H2O2/PMS system. The MnO2/UIO-66 also displayed prominent stability and recyclability. The effect of initial pH on OTC degradation was studied. The effects of inorganic anions such as CO32−, HCO3−, SO42−, Cl− and NO3− on the degradation of OTC was also being studied. This study showed that MnO2/UIO-66 composite had great potential in antibiotic-contaminated wastewater treatment. Most importantly, reliable free radical attack sites were proposed based on density functional theory (DFT) calculation.
Novel MnO2/UIO-66 composites were fabricated to achieve efficient OTC degradation with the addition of PMS/H2O2 under UV-light illumination. Display omitted
•The prepared MnO2 had a rod-like structure.•MnO2/UIO-66 composite was an efficient photocatalyst for OTC cleanup.•PMS/H2O2 system exhibited synergistic effect in OTC degradation.•DFT calculation with high Fukui index revealed the vulnerable sites on OTC.
Oxytetracycline (OTC) is a widely used antibiotic in aquaculture. In this study, red seabream (Pagrus major), the most popular aquaculture species in Japan, were treated with OTC mimicking a real ...administration scenario in aquaculture. The treatment groups were as follows: no OTC, 40 mg/kg body wt/day (equivalent to the dose used in actual aquaculture), or 178 mg/kg body wt/day. The first exposure was conducted for a week (1st OTC exposure period), followed by a 4-week interval, and the second exposure was for one week (2nd OTC exposure period). We investigated the effects of OTC on the liver proteome with the isobaric tags for relative and absolute quantitation (iTRAQ) technology accompanied by liquid chromatography and mass spectrometry. The pathway and disease enrichment analyses of differentially abundant proteins in OTC-exposed groups compared to their respective controls showed that the abundance of proteins related to the immune and nervous systems was altered after the 1st and 2nd OTC exposures, respectively. Quantitative real-time PCR of the transcripts of immune-related genes corroborated with the results of proteome analysis. OTC exposure also modulated the expression of metabolism-related proteins after the 1st and 2nd OTC exposures. Furthermore, after four weeks of the 2nd exposure, weight loss and changes in the expression of proteins related to metabolism were observed, suggesting that OTC exposure disrupts the metabolic system and causes growth inhibition. Based on these results, we suggest that the use of OTC in aquaculture poses a health risk in fish species. Thus, we need to pay more attention to the contamination with OTC in aquaculture.
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•Effects of oxytetracycline (OTC) exposure on red seabreams were investigated.•OTC exposure mimicked a real administration scenario.•Hepatic proteome was analyzed 1 day and 4 weeks after OTC exposure.•Proteins related to immune, metabolic, and neuronal systems were affected.•Alterations in the hepatic proteome by OTC may account for growth inhibition.
This study developed a new water treatment method using liquid-phase plasma (LPP) process that can decompose oxytetracycline (OTC) remaining in the aquatic environment. Relatedly, the OTC causes ...damage to the human body and cannot be removed by traditional water treatment methods. The study also prepared Fe/TiO2 photocatalyst responding to visible light using the LPP process. In particular, the OTC decomposition efficiency of the LPP process improved by more than 10% with the use of the Fe/TiO2 photocatalyst as compared to that of the one with the use of bare TiO2 photocatalyst. Further, the optimal LPP process parameters and Fe/TiO2 photocatalyst amount in the LPP process for OTC decomposition were established in the study. Finally, the degradation pathway of the OTC in the LPP process was found based on the five intermediates of the LPP reaction that were detected by the liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analysis. In particular, the decomposition pathway was estimated to be involving the mineralization of the OTC through demethylation, deamination, dehydration, and ring cleavage.
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•Prepare of visible light-responsive Fe/TiO2 photocatalysts by LPP method.•The band gap energy of TiO2 photocatalysts was lowered by iron precipitated.•OCT in water was successfully removed by the LPP process alone.•Fe/TiO2 was effectively used to mineralize the oxytetracycline antibiotic.•OTC is mineralized by two decomposition pathways by oxidizing agents such as OH radicals.
Emission of antibiotics into riverine environments affects aquatic ecosystem functions and leads to the development of antibiotic resistance. Here, the profiles of forty-four antibiotics and eighteen ...antibiotic resistance genes (ARGs) were analyzed in two large rivers of the Pearl River System. In addition, the risks of ecotoxicity and resistance selection posed by the antibiotics were estimated. As compared to the reservoirs, the river sections close to the urban and livestock areas contained more antibiotics and ARGs. Seasonal variations of antibiotics (higher in the dry season) and relative ARGs (normalized by 16S rRNA gene, higher in the wet season) were found in the water, but not in the sediment. Sulfonamide resistance genes were the most prevalent ARGs in both river water and sediment. Antibiotic concentration was correlated with ARG abundance in the water, indicating that antibiotics play a critical role in ARG spread. In addition, oxytetracycline was the most abundant antibiotic with concentrations up to 2030 ng/L in the water and 2100 ng/g in the sediment respectively, and posed the highest risks for resistance selection. Oxytetracycline, tetracycline and sulfamethoxazole were expected to be more ecotoxicologically harmful to aquatic organisms, while ofloxacin, enrofloxacin, norfloxacin, chlortetracycline, oxytetracycline and tetracycline posed ecotoxicological risks in the sediment. The Nanliujiang river with intensive livestock activities was contaminated by antibiotics and ARGs and faced high ecotoxicological and resistance selection risks. Collectively, these findings reflect the impacts of anthropogenic activities on the spread of antibiotic resistance in large river basins.
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•Tetracyclines were the major antibiotics in both river waters and sediments.•Sulfonamide resistance genes were prevalent in the rivers except reservoirs.•Antibiotics were the major drivers of antibiotic resistance in large river basins.•OTC produced the most serious ecological risks to the rivers.•Nanliujiang river faced the most antibiotic resistance and ecological risks.
Because broiler chickens can meet human nutritional demands, they are commonly consumed in many nations worldwide. Although the abuse of antibiotics in the chicken business has had major negative ...effects on public health, antibiotics have been used in broiler diets to minimize poultry infections and increase growth performance. Probiotics are therefore a secure and healthful substitute for antibiotics. Pediococcus pentosaceus is a promising strain of lactic acid bacteria (LAB) which is gradually attracting attention, leading to a rapid increase in experimental research. Pediococcus pentosaceus strains can be applied as an animal growth bio-promoter and as a probiotic. However, information on the use of Pediococcus pentosaceus as a probiotic remain scanty. This study was therefore conducted to investigate the effects of different doses of Pediococcus pentosaceus GT001 supplementation on the growth performance, immune function, intestinal development and histomorphology of broilers and to understand the protective mechanisms of Pediococcus pentosaceus GT001 probiotics on the host. Exploring alternatives to antibiotics is imperative in reducing antibiotic resistance and antibiotic residues in poultry products. The beneficial effects of antibiotic products derived from natural sources in comparison with the synthetic ones has been reported. Pediococcus pentosaceus has been applied as an animal growth bio-promoter and probiotic. To elucidate the protective mechanisms of P. pentosaceus, this study investigated the effects of different doses of P. pentosaceus supplementation on broiler growth performance, immune function, intestinal development and histomorphology. Five hundred (500) one-day-old Ross 708 broiler chicks were randomly enrolled into five experimental groups with 20 chicks per replicate. The treatments were imposed as follows: (T1) basal diet (control); (T2) basal diet with 1 g/kg antibact 3X; (T3) basal diet with P. pentosaceus GT001 at 4.0 × 10sup.8 cfu/g; (T4) basal diet with P. pentosaceus GT001 at 8.0 × 10sup.8 cfu/g; and (T5) basal diet with P. pentosaceus GT001 at 1.2 × 10sup.9 cfu/g. Dietary inclusion of P. pentosaceus GT001 at 4.0 × 10sup.8 cfu/g significantly improved body weight gain, feed intake and lipid profile of the broilers compared to the control group (p < 0.05). The addition of P. pentosaceus GT001 significantly improved the intestinal pH of the broilers. The digestive enzymes of the broilers were impacted with the supplementation of P. pentosaceus GT001 at 4.0 × 10sup.8 cfu/g. The highest serum antioxidant production was observed in the P. pentosaceus-treated group compared to the control. P. pentosaceus GT001 at 4.0 × 10sup.8 cfu/g increased the levels of serum cytokines and immunoglobin and improved the small intestinal morphology of the broilers in comparison with the control. The load of Pedococcus spp was similar among T3, T4 and T5 but significantly higher than that of the control (T1) and the antibiotics (T2)-fed birds. The load of E. coli in the gut was significantly reduced in T3, T4 and T5 compared to T1 and T2. There was no Salmonella growth among the treatments. This study highlights the importance of probiotics in broiler diets and suggests that Pediococcus pentosaceus GT001 could be used as a feasible substitute to antimicrobials in broiler production.
