The large molecular weight and high hydrophilicity of chloramphenicol(CAP) residuals in wastewater led to severe degradation difficulty,which propelled the development of new wastewater degradation processes and react...The large molecular weight and high hydrophilicity of chloramphenicol(CAP) residuals in wastewater led to severe degradation difficulty,which propelled the development of new wastewater degradation processes and reactors based on process intensification.This study enhanced the CAP degradation by ozone/peroxydisulfate(PDS) advanced oxidation process in a submerged rotating packed bed(SRPB)reactor.Compared the usage of different oxidants,it was indicated that the combination of O_(3) and PDS exhibited a higher degradation efficiency than ozone and PDS alone.The more desired degradation efficiency could be achieved at the operating conditions of ascending PDS concentration,SRPB rotational speed,ozone concentration,reduced initial CAP concentration,and the water qualities of ascended pH,lower Cl^(-)and initial CO_(3)^(2-) concentrations.Under the optimized conditions of C_(CAP)=20 mg·L^(-1),C_(O3)=30 mg·L^(-1),C_(PDS)=100 mg·L^(-1),and N=400 r·min^(-1),and water qualities of pH=10,the maximum chloramphenicol degradation efficiency of 97% and kinetic constant of 0.23 min^(-1) were achieved after treating 16 min.A comparison of the results with previously reported advanced oxidation processes of CAP indicated that the enhanced O^(3)/PDS advanced oxidation system using the SRPB can significantly improve the degradation efficiency of CAP.展开更多
[Objectives]To observe the effects of chloramphenicol prednisone liniment on anti-inflammatory and anti-pruritic responses and skin barrier function in an acute eczema mouse model and explore its potential underlying ...[Objectives]To observe the effects of chloramphenicol prednisone liniment on anti-inflammatory and anti-pruritic responses and skin barrier function in an acute eczema mouse model and explore its potential underlying mechanism.[Methods]Twenty-four female SPF-grade ICR mice were randomly and equally assigned to three groups:the blank control group,the acute eczema group,and the chloramphenicol prednisone liniment group according to the random number table method,with 8 mice per group.Except for the blank control group,the acute eczema model was established by applying 2,4-dinitrochlorobenzene(DNCB)to the right dorsal area.On day 10(d10),0.1 mL of normal saline was administered to the modeling site in both the blank control group and the acute eczema group,whereas chloramphenicol prednisone liniment was applied to the positive drug group.Medication was applied twice daily in all three groups for a total duration of 14 d.Sixty minutes following the final administration of the drug,the development of eczema in mice was visually assessed,and the severity of skin lesions was scored.Trans-epidermal water loss(TEWL)was measured using a multifunctional skin tester.Experiments inducing and alleviating pruritus were performed to compare the frequency of mice licking their bodies,the latency period before pruritus onset,and the duration of pruritus episodes.Levels of histamine and substance P(SP)in the lesion tissues were quantified using enzyme-linked immunosorbent assay(ELISA).[Results]Compared to the acute eczema group,the chloramphenicol prednisone liniment group exhibited a prolonged latency period of pruritus,an increased inhibition rate,and a shortened duration of pruritus.Additionally,there was a significant reduction in the frequency of mice licking their bodies,as well as in six eczema severity indicators:redness and swelling,scratch marks,papules,blisters,exudation or erosion at the lesion site,and the degree of skin swelling.Furthermore,levels of TEWL,histamine,and SP were also significantly decreased(P<0.05).[Conclusions]Chloramphenicol prednisone liniment exhibits anti-inflammatory and anti-pruritic properties.Its mechanism of action may involve the inhibition of mast cell activation within the lesion tissues of eczema model mice,thereby reducing the release of histamine and other active substances.This process alleviates inflammatory damage associated with eczema and contributes to the restoration of skin barrier function.展开更多
The experimental design methodology was applied for modeling and optimizing the operation parameters on photocatalytic degradation of chloramphenicol （CAP） using TiO 2 as photocatalyst in a photoreactor. Three exper...The experimental design methodology was applied for modeling and optimizing the operation parameters on photocatalytic degradation of chloramphenicol （CAP） using TiO 2 as photocatalyst in a photoreactor. Three experimental parameters （including pH, TiO 2 concentration and CAP initial concentration） were adopted to obtain the preliminary information. The multivariate experimental design was employed to establish a quadratic model as a functional relationship between the degradation rate of CAP and three experimental parameters. The interaction effects and optimal parameters were obtained by using Design Expert software. The optimal values of the operation parameters under the related constraint conditions were found at pH 6.4, TiO 2 concentration of 0.94 g/L and CAP initial concentration of 19.97 mg/L, respectively. The degradation rate of CAP approached 85.97% under optimal conditions. The regression analysis with R 2 value of 0.9519 had a good agreement between the experimental results and the predictive values. In addition, pH and TiO 2 concentration had a significant influence on the degradation rate of CAP.展开更多
Exposure to chloramphenicol（CAP）,a chlorinated nitroaromatic antibiotic,can induce CAP-resistant bacteria/genes in diverse environments. A biocathode bioelectrochemical system（BES） was applied to reduce CAP under ...Exposure to chloramphenicol（CAP）,a chlorinated nitroaromatic antibiotic,can induce CAP-resistant bacteria/genes in diverse environments. A biocathode bioelectrochemical system（BES） was applied to reduce CAP under switched operational temperatures.When switching from 25 to 10°C,the CAP reduction rate（kCAP） and the maximum amount of the dechlorinated reduced amine product（AMCl,with no antibacterial activity） by the biocathode communities were both markedly decreased. The acetate and ethanol yield from cathodophilic microbial glucose fermentation（with release of electrons） was also reduced. Formation of the product AMCl was enhanced by the biocathode dechloridation reaction compared with that produced from pure electrochemical or microbial dechloridation processes. The electrochemical and morphological analyses of cathode biofilms demonstrated that some cathodophilic microbes could adapt to low temperature and play a key role in CAP degradation. The resilient biocathode BES has a potential for the treatment of CAP-containing wastewater in temperature fluctuating environments.展开更多
In this study, we synthesized molybdenum disulfide/polyaniline（MoS2/PANI） nanocomposite via in situ polymerization of aniline in the presence of thin-layered MoS2. The as-prepared MoS2/PANI nanocomposite obtained an...In this study, we synthesized molybdenum disulfide/polyaniline（MoS2/PANI） nanocomposite via in situ polymerization of aniline in the presence of thin-layered MoS2. The as-prepared MoS2/PANI nanocomposite obtained an improved electrochemical performance due to the physisorption interaction between aromatic aniline and the basal plane of MoS2. Furthermore, we constructed a new kind of electrochemical sensor based on MoS2/PANI nanocomposite for the detection of chloramphenicol, which showed an excellent performance. The sensor has a high sensitivity and wide detection range from 1 ×10^（-7）mol/L to 1×10^（-4）mol/L, with a low detection limit of 6.9 × 10^（-8）mol/L.展开更多
In this article, poly（2-hydroxyethylmethacrylate-co-acrylamide） hydrogels were synthesized by bulk free-radical copolymerization of 2-hydroxyethylmethacrylate （HEMA） and acrylamide （AAm） for soft contact lens（...In this article, poly（2-hydroxyethylmethacrylate-co-acrylamide） hydrogels were synthesized by bulk free-radical copolymerization of 2-hydroxyethylmethacrylate （HEMA） and acrylamide （AAm） for soft contact lens（SCL）-based ophthalmic drug delivery system. The copolymer was characterized with FT-IR and SEM, the swelling property of the hydrogels were studied by gravimetrical method, and chloramphenicol was used as a model drug to investigate drug release profile of the hydrogels. The results showed that poly（2-hydroxyethylmethacrylateco-acrylamide） hydrogels were transparent and useful SCL biomaterial, the water content increased as AAm content increase and pH decrease, and in the same way, hydrogel composition affected chloramphenicol release process too. Migration rate of chloramphenicol increased as the AAm content in the hydrogels increased in the first stage of diffusion process, whereas there was no significant difference thereafter.展开更多
hloramphenicol is an antibiotic and one of the potential contaminants in honey.Solid-phase extraction is the key pretreatment procedure for analysis of chloramphenicol in honey.In this work,an on-line pretreatment liq...hloramphenicol is an antibiotic and one of the potential contaminants in honey.Solid-phase extraction is the key pretreatment procedure for analysis of chloramphenicol in honey.In this work,an on-line pretreatment liquid chromatography-tandem mass spectrometer system for sensitive,reliable and higher throughput analysis was developed.With the methylcellulose-immobilized reversed-phase column,sugars in a honey sample were efficiently removed in 1 min.As a result,the limit of quantitation of chloramphenicol was 20 pg/mL（0.2 μg/kg honey）.展开更多
[ Objective] This study was conducted to establish a new UPLC-MS method for simultaneous detection of sulfonanfides and chloramphenicols in honey. [ Method] In this experiment, 0.2% formic acid-acetonitrile was used a...[ Objective] This study was conducted to establish a new UPLC-MS method for simultaneous detection of sulfonanfides and chloramphenicols in honey. [ Method] In this experiment, 0.2% formic acid-acetonitrile was used as an extractant to simultaneously extract chloramphenicoJs and sulfonamides from drugs. The extract was then loaded and extracted with an efficient separation column Oasis PRIME HLB. After nitrogen blow-concentration and dissolution with mobile phase, the extract was loaded on UPLC and detected by MS. [ Resultl There was a good linear relation in the range of 0. 1 - 10 ng/ml for chloramphenicols, with a correlation coefficient of 0.991, while sulfonamides had a good linear relation in the range of 0.5 - 50 ng/ml. The lowest detection limit of chloramphenicols and sulfonamides were 0. 1 and 0.5 μg/kg, respectively. The recoveries were in the range of 82.50% - 101.2%, with RSD values in the range of 3.2% -4.0%. [ Conclusion] This method is simple and fast with low detection limit, high recovery and good reproducibility, and could be used for simultaneous detection of re- sidual chloramphenicols and sulfonamides in honey. Key words UHPLC-MS; Sulfonamides ; Chloramphenicols ; Honey展开更多
The purpose of this study was to evaluate the potential of electron beam to decompose chloramphenicol （CAP） in aqueous solutions. At the absorbed dose of 15 kGy, the decomposition rate of CAP was 95.24%. The degrada...The purpose of this study was to evaluate the potential of electron beam to decompose chloramphenicol （CAP） in aqueous solutions. At the absorbed dose of 15 kGy, the decomposition rate of CAP was 95.24%. The degradation of CAP under electron beam irradiation followed pseudo-first-order kinetics. Redox reactions of CAP aqueous solutions with hydroxyl radicals （.OH）, hydrated electrons （eaq） and hydrated atoms （·H） were studied. The increase of the additives would result in the decrease of the degradation efficiency. The concentration of Cl- and NO3- in aqueous solution increased after electron beam irradiation. On the basis of the experimental results, a photocatalytic mechanism was discussed. The rate constant for reactions of .OH and CAP was 9.36×10^7 L/（mol.s） and for reaction of eaq and CAP was 7.33×10^7 L/（mol.s）..OH was supposed to play the key role in the radiation system of aqueous solution. Other free radicals like eaq and .H could also initiate the degradation.展开更多
Waste polyolefin plastics, accounting for 50% of all plastic waste, represent a tremendously unexploited carbon source. Efficiently upcycling polyolefin waste into value-added carbon materials for waste water treatmen...Waste polyolefin plastics, accounting for 50% of all plastic waste, represent a tremendously unexploited carbon source. Efficiently upcycling polyolefin waste into value-added carbon materials for waste water treatment avoiding using noble metals is challenging but economically and environmentally sustainable. In this work, MAX-Ti_(3)AlC_(2) supported Fe selectively catalyzes polyolefin into few-layered graphene in 5 min under microwave treatment. Graphene and MAX supported Fe(Fe@MLC) can completely(99.9%)degrade chloramphenicol(CAP) within 60 min, retain robust after 10 cycles and work efficiently at a wide p H range(3.87–13.03), avoiding the usage of noble metal. Moreover, the electrochemical active surface area(ECSA) of Fe@MLC is 2.7 times higher than that of commercial Pt/C. This work provides a cheap and efficient catalyst that promotes deconstruction of plastic wastes and indirectly degrades antibiotics thereby realizes the treatment of waste water with waste plastic.展开更多
BiOI/ZnO/rGO(reduced graphene oxide) composite photocatalyst was fabricated using a simple one-step hydrothermal process and applied to the degradation of antibiotic chloramphenicol(CAP). By tuning the Bi/Zn ratios, t...BiOI/ZnO/rGO(reduced graphene oxide) composite photocatalyst was fabricated using a simple one-step hydrothermal process and applied to the degradation of antibiotic chloramphenicol(CAP). By tuning the Bi/Zn ratios, the structure and photoelectric properties of the catalyst were investigated and characterized in terms of their morphological, structural, optical and photoelectrochemical properties. The as-synthesized composite photocatalysts are well-crystalline, uniform dispersion and exhibit good photocatalytic properties.The photocatalytic degradation rate of CAP by BiOI/ZnO/rGO composite is 8.1 times and 1.8times that of BiOI and ZnO, respectively. The photocatalytic mechanism studies revealed that the synergistic effect between rGO and BiOI/ZnO can effectively separate photogenerated electron–hole, enhance photocurrents and conductivity, and improve charge carrier densities. Moreover, BiOI/ZnO/rGO possesses good stability and reusability that the degradation efficiency remained above 80% even after 5 recycling. This study reveals that both the introduction of rGO and heterostructure construction between BiOI and ZnO play a crucial role in their photoelectrochemical and photocatalytic properties.展开更多
A new,simple,rapid microbial assay was put forward for the detection of chloramphenicol(CAP)residues in Turbot muscles using luminescent bacteria DB(Photobacterium phosphoreum)as test organ-ism.By the luminescence inh...A new,simple,rapid microbial assay was put forward for the detection of chloramphenicol(CAP)residues in Turbot muscles using luminescent bacteria DB(Photobacterium phosphoreum)as test organ-ism.By the luminescence inhibition of DB,the concentrations of CAP were determined.CAP spiked inTurbot muscle tissues ranging from 0.5 to 100μg/kg was extracted using ethyl acetate and hexane.Themethod had a good recovery of 93.69% with a minimum detection limit of 0.65μg/kg.It can be per-formed within 30min following simple extraction.The method therefore proved to be advantageous overchromatographic procedures as it was inexpensive,quite sensitive and can be adopted for rapid screeningof CAP in Turbot tissues.展开更多
Objective:To evaluate the antibacterial activity of Ocimum sanctum(O.sanctum) leaf extract, alone,and in combination with chloramphenicol(C) and trimethoprim(Tm) against Salmonella enterica serovar Typhi(S.typhi).Meth...Objective:To evaluate the antibacterial activity of Ocimum sanctum(O.sanctum) leaf extract, alone,and in combination with chloramphenicol(C) and trimethoprim(Tm) against Salmonella enterica serovar Typhi(S.typhi).Methods:The antibacterial activity of ethanolic extract of tulsi, 0.sanctum,leaf(TLE:500μg) for 23 S.typhi isolates was determined following agar diffusion. The C(30μg) and Tm(5μg) activity alone and in combination with TLE(250μg) was determined by disk diffusion.The zone diameter of inhibition(ZDI) for the agents was recorded, and growth inhibitory indices(Glls) were calculated.Results:The S.typhi isolates(n=23),which were resistant to both C(ZDI 6 mm) and Tm(ZDI 6 mm),had TLE(500μg) ZDIs 16-24 mm.The ZDIs of C and Tm were increased up to 15-21 mm and 17-23 mm,respectively,when TLE(250μg) was added to the C and Tm discs.The Glls ranged 0.789-1.235 and 0.894-1.352,due to combined activity against S.typhi isolates,of C and TLE and Tm and TLE.respeclivelv.Conclusions:The data suggest that TLE,in combination with C and Tm,had synergistic activity for S.typhi isolates, and hence O.sanclum is potential in combating S.typhi drug resistance,as well promising in the development of non-antibiotic drug for S.typhi infection.展开更多
Objective: To investigate the roles of chloramphenicol (CAP) preconditioning in the oxidative respiratory function of cerebral mitochondria in rats exposed to acute hypoxia during acute hypoxia by observing the change...Objective: To investigate the roles of chloramphenicol (CAP) preconditioning in the oxidative respiratory function of cerebral mitochondria in rats exposed to acute hypoxia during acute hypoxia by observing the changes of mitochondrial oxidative respiratory function and cytochrome C oxidase (COX) activity. Methods: Adult male Wistar rats were randomly divided into 4 groups: control (C), medication (M), hypoxia (H), and medication plus hypoxia (MH). Rats in groups M and MH were administered by peritoneal injection of CAP (50 mg/kg) every 12 h for 7 d before decapitation, but those in groups H and MH were exposed to a hypobaric chamber simulating 5 000 m high altitude for 24 h. The rat cerebral cortex was removed and mitochondria were isolated by centrifugation. Mitochondrial respiratory function and COX activity were measured by Clark oxygen electrode. Results: Compared with Group C, Group H showed significantly elevated state 4 respiration (ST 4), decreased state 3 respiration (ST 3), and respiratory control rate (RCR) in mitochondrial respiration during acute hypoxic exposure. ST 3 in Group MH was significantly lower than that in Group C, but was not significantly different from that in Groups H and M, while ST 4 in Group MH was significantly lower than that in groups C and H. RCR in Group MH was higher than that in Group H, but lower than that in Group C. COX activity in Group H was significantly lower than that in Group C. In Group MH, COX activity increased and was higher than that in Group H, but was still lower than that in Group C. Conclusion: Acute hypoxic exposure could lead to mitochondrial respiratory dysfunction, suggesting that CAP preconditioning might be beneficial to the recovery of rat respiratory function. The change of COX activity is consistent with that of mitochondrial respiratory function during acute hypoxic exposure and CAP-administration, indicating that COX plays an important role in oxidative phosphorylation function of mitochondria from cerebral cortex of hypoxic rats.展开更多
[Objectives]To observe and analyze the clinical efficacy and possible mechanism of Chuanbai antipruritic lotion"water film"wet compress combined with chloramphenicol prednisone liniment in the treatment of a...[Objectives]To observe and analyze the clinical efficacy and possible mechanism of Chuanbai antipruritic lotion"water film"wet compress combined with chloramphenicol prednisone liniment in the treatment of acute eczema.[Methods]A total of 76 acute eczema cases admitted to Shiyan Taihe Hospital from January 2022 to March 2023 were divided into Western medicine treatment group and integrated traditional Chinese and Western medicine group.In the Western medicine treatment group,chloramphenicol and prednisone liniment was applied to the skin lesions and oral administration of cetirizine hydrochloride.The course of treatment in both groups was 2 weeks(w).The levels of interferon-γ(IFN-γ),interleukin-4(IL-4)and the ratio of IFN-γ/IL-4 in the peripheral blood of patients before and 2 weeks after treatment,as well as serum immunoglobulin E(IgE),anti-IgE antibody and histamine(HA)level,and with skin lesions disappearing time,skin oil,transepidermal water loss(TEWL),eczema area and severity index(EASI)score,total effective rate,degree of pruritus and traditional Chinese medicine quality of life scale(EPQOLS)score to evaluate the efficacy.[Results]Compared with the Western medicine treatment group at 2 w,the disappearance time of skin lesions in the integrated traditional Chinese and Western medicine group was shortened,TEWL,itching degree and EASI score,serum IgE and HA,and peripheral blood IL-4 levels were all decreased(P<0.05).IFN-γand IFN-γ/IL-4 ratio,anti-IgE antibody,EPQOLS score and total effective rate were all increased(P<0.05),and the difference was statistically significant.[Conclusions]Chuanbai antipruritic lotion"water film"wet compress combined with chloramphenicol prednisone liniment is an optimized and safe and efficient method for the treatment of acute eczema,which can quickly relieve the symptoms of inflammatory damage of eczema and restore the skin barrier function,dry dampness and relieve itch.Inhibition of the release of histamine active substances and regulation of immunity may be the main mechanisms.展开更多
Purpose: While there were numerous clinical examples of ocular damage, the histopathology of retinal responses was poorly characterized, and animal model research was limited. The consequences of retinal lesions with ...Purpose: While there were numerous clinical examples of ocular damage, the histopathology of retinal responses was poorly characterized, and animal model research was limited. The consequences of retinal lesions with traditional medicine treatment were mostly unknown. In this work, goldfish was employed as a model for penetrating injury of the eyes to study the ocular trauma with antibiotic and traditional medicine treatments. Materials and Methods: The penetration of the eyes was performed at 2mm above the midline of the limbus in the superior quadrant with an 18-gauge sterile needle, all the way to the retina but avoiding the lens while the animals were anaesthetized in water containing 100 mg/L ethyl 3-aminobenzoate methanesulfonate (MS-222). The animals were divided into three groups and received treatments of saline, chloramphenicol, and Angong Niuhuang pill (Angong) eyedrops twice a day respectively. Angong after seven days, the animals were sacrificed. Immunohistochemical evaluation of proliferative cell nuclear antigen (PCNA), brain-derived neurotrophic factor (BDNF), catalase, and cleaved caspase-3, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) for apoptotic cells were performed on the fish’s superior quadrants of the retinae. The whole experiment was repeated two times. Result: It was evident that both the retinae treated with chloramphenicol and Angong had fewer apoptotic cells and more proliferative cells, particularly in the cases of the Angong treatment. BDNF was in the inner nuclear layer and ganglion cell layer of all groups. In the chloramphenicol and Angong groups, some cells in the outer nuclear layer displayed BDNF. Catalase reactions confirmed equivalent findings that the treated retinae with chloramphenicol or Angong treatment had less catalase. Conclusion: Angong Niuhuang pill is a traditional medicine composite formula with antibiotic and neuroprotective effects on the brain and the eyes, and this work also pointed out its possible pharmaceutical potential.展开更多
The aim is to evaluate the effect of ciprofloxacin and chloramphenicol on anti-BSA antibody production triggered by bovine albumin encapsulated in non-ionic surfactant vesicle,niosomes.Reverse phase evaporation method...The aim is to evaluate the effect of ciprofloxacin and chloramphenicol on anti-BSA antibody production triggered by bovine albumin encapsulated in non-ionic surfactant vesicle,niosomes.Reverse phase evaporation method was adopted to entrap the antigen in colloidal carrier composed of Span 80 and Span 85 followed by simultaneous characterization for particle size,entrapment efficiency and in vitro release.The protein content was determined by Bradford method using UV Visible Spectrophotometer at 595 nm.Humoral immune response was measured in terms of systemic IgG antibody titre by ELISA method.Experimental data indicated that 7∶3 molar ratio of Span 80 and cholesterol based niosomal formulation possessed maximum(39.8±2.9)% of soluble protein.Ciprofloxacin markedly(P<0.05) decreased the antibody titre.In contrast,chloramphenicol did not reduce the antibody titre significantly in comparison to control group(P>0.05).It is necessary to explore the effect of a vaccine antigen when a candidate is medicated with a therapeutic agent,which might help in programming a new drug management and vaccination programme.展开更多
Conventional wastewater treatment facilities lack the appropriate design to abate the presence of antibiotics,which are potential hazards in natural water sources.The use of electroactive bacteria and biochar to elimi...Conventional wastewater treatment facilities lack the appropriate design to abate the presence of antibiotics,which are potential hazards in natural water sources.The use of electroactive bacteria and biochar to eliminate antibiotics has been reported;however,the impact and underlying mechanisms by which biochar enhances the biodegradation of antibiotics by electroactive microorganisms remain unclear.As chloramphenicol exhibits a high degree of toxicity to aquatic organisms,this study investigated the synergistic effect of biochar on the biodegradation of chloramphenicol by electroactive Shewanella oneidensis MR-1.Biochar significantly improved chloramphenicol degradation rates from 36.05%to 70.79%within 24 h by promoting electron transfer processes in S.oneidensis MR-1,a typical electroactive microorganism.This study offers unique insights into the electrochemical properties of biochar,particularly those influenced by pyrolysis temperature,in enhancing the microbial electron transfer processes.Furthermore,the findings demonstrated that biochar not only promotes the growth and activity of electroactive bacteria but also facilitates direct and indirect electron transfer mechanisms,leading to significantly improved antibiotic degradation rates.In summary,biochar is a novel perspective in environmental biotechnology that offers an innovative approach to address the challenge of persistent antibiotics in wastewater treatment.展开更多
Geobacter metallireducens is known to be capable of removing nitroaromatic compounds via an oxidation mode. However, little attention has been paid to investigate the reductive removal of chlorinated nitroaromatic com...Geobacter metallireducens is known to be capable of removing nitroaromatic compounds via an oxidation mode. However, little attention has been paid to investigate the reductive removal of chlorinated nitroaromatic compounds by G. metallireducens. In this study, G. metallireducens was used to reduce chloramphenicol(CAP), a typical chlorinated nitroaromatic antibiotic. Cyclic voltammograms and chronoamperometry highlighted a higher peak current for CAP reduction by G. metallireducens compared to the control without bacteria. G. metallireducens efficiently reduced CAP(20 mg/L) with acetate as the sole electron donor, and the removal efficiency reached(97.6±4.9)% within 6 d. Aromatic amine(AMCl2), AMCl(dechlorinated AMCl2) and AM(dechlorinated AMCl) were identified as reduction products by liquid chromatography-mass spectrometry. However, the removal efficiency declined to(25.0±3.6)% when the CAP dosage increased to 80 mg/L. Transcriptomic analysis indicated the significant upregulation of genes related to electron transfer, such as pilus assembly protein gene(2.8 folds), NADH-quinone oxidoreductase subunit K2 gene(4.5 folds) and many c-type cytochrome genes such as cytochrome c biogenesis protein Res B(Gmet 2901, 4.6 folds), cytochrome c(Gmet 0335, 4.4 folds) and cytochrome c7(Gmet 2902, 3.4 folds). Furthermore, a gene related to chlorinated contaminant removal(Gmet 1046, 5.4 folds) was also upregulated, possibly resulting in enhanced CAP reduction. This work deepened our knowledge of the bioremediation ability of G. metallireducens with respect to environmental contaminants and provided a potential strategy to treat antibiotics with electrochemically active bacteria.展开更多
基金supported by the National Natural Science Foundation of China(22288102)。
文摘The large molecular weight and high hydrophilicity of chloramphenicol(CAP) residuals in wastewater led to severe degradation difficulty,which propelled the development of new wastewater degradation processes and reactors based on process intensification.This study enhanced the CAP degradation by ozone/peroxydisulfate(PDS) advanced oxidation process in a submerged rotating packed bed(SRPB)reactor.Compared the usage of different oxidants,it was indicated that the combination of O_(3) and PDS exhibited a higher degradation efficiency than ozone and PDS alone.The more desired degradation efficiency could be achieved at the operating conditions of ascending PDS concentration,SRPB rotational speed,ozone concentration,reduced initial CAP concentration,and the water qualities of ascended pH,lower Cl^(-)and initial CO_(3)^(2-) concentrations.Under the optimized conditions of C_(CAP)=20 mg·L^(-1),C_(O3)=30 mg·L^(-1),C_(PDS)=100 mg·L^(-1),and N=400 r·min^(-1),and water qualities of pH=10,the maximum chloramphenicol degradation efficiency of 97% and kinetic constant of 0.23 min^(-1) were achieved after treating 16 min.A comparison of the results with previously reported advanced oxidation processes of CAP indicated that the enhanced O^(3)/PDS advanced oxidation system using the SRPB can significantly improve the degradation efficiency of CAP.
文摘[Objectives]To observe the effects of chloramphenicol prednisone liniment on anti-inflammatory and anti-pruritic responses and skin barrier function in an acute eczema mouse model and explore its potential underlying mechanism.[Methods]Twenty-four female SPF-grade ICR mice were randomly and equally assigned to three groups:the blank control group,the acute eczema group,and the chloramphenicol prednisone liniment group according to the random number table method,with 8 mice per group.Except for the blank control group,the acute eczema model was established by applying 2,4-dinitrochlorobenzene(DNCB)to the right dorsal area.On day 10(d10),0.1 mL of normal saline was administered to the modeling site in both the blank control group and the acute eczema group,whereas chloramphenicol prednisone liniment was applied to the positive drug group.Medication was applied twice daily in all three groups for a total duration of 14 d.Sixty minutes following the final administration of the drug,the development of eczema in mice was visually assessed,and the severity of skin lesions was scored.Trans-epidermal water loss(TEWL)was measured using a multifunctional skin tester.Experiments inducing and alleviating pruritus were performed to compare the frequency of mice licking their bodies,the latency period before pruritus onset,and the duration of pruritus episodes.Levels of histamine and substance P(SP)in the lesion tissues were quantified using enzyme-linked immunosorbent assay(ELISA).[Results]Compared to the acute eczema group,the chloramphenicol prednisone liniment group exhibited a prolonged latency period of pruritus,an increased inhibition rate,and a shortened duration of pruritus.Additionally,there was a significant reduction in the frequency of mice licking their bodies,as well as in six eczema severity indicators:redness and swelling,scratch marks,papules,blisters,exudation or erosion at the lesion site,and the degree of skin swelling.Furthermore,levels of TEWL,histamine,and SP were also significantly decreased(P<0.05).[Conclusions]Chloramphenicol prednisone liniment exhibits anti-inflammatory and anti-pruritic properties.Its mechanism of action may involve the inhibition of mast cell activation within the lesion tissues of eczema model mice,thereby reducing the release of histamine and other active substances.This process alleviates inflammatory damage associated with eczema and contributes to the restoration of skin barrier function.
文摘The experimental design methodology was applied for modeling and optimizing the operation parameters on photocatalytic degradation of chloramphenicol （CAP） using TiO 2 as photocatalyst in a photoreactor. Three experimental parameters （including pH, TiO 2 concentration and CAP initial concentration） were adopted to obtain the preliminary information. The multivariate experimental design was employed to establish a quadratic model as a functional relationship between the degradation rate of CAP and three experimental parameters. The interaction effects and optimal parameters were obtained by using Design Expert software. The optimal values of the operation parameters under the related constraint conditions were found at pH 6.4, TiO 2 concentration of 0.94 g/L and CAP initial concentration of 19.97 mg/L, respectively. The degradation rate of CAP approached 85.97% under optimal conditions. The regression analysis with R 2 value of 0.9519 had a good agreement between the experimental results and the predictive values. In addition, pH and TiO 2 concentration had a significant influence on the degradation rate of CAP.
基金supported by the National Science Foundation for Distinguished Young Scholars of China (No.51225802)the National Natural Science Foundation of China (No.51178140)+2 种基金the National Creative Research Groups Project (No.51121062)the State Key Laboratory of Urban Water Resource and Environment of HIT (No.2013DX02)the Hundred Talents Program of the Chinese Academy of Sciences (No.29BR2013001)
文摘Exposure to chloramphenicol（CAP）,a chlorinated nitroaromatic antibiotic,can induce CAP-resistant bacteria/genes in diverse environments. A biocathode bioelectrochemical system（BES） was applied to reduce CAP under switched operational temperatures.When switching from 25 to 10°C,the CAP reduction rate（kCAP） and the maximum amount of the dechlorinated reduced amine product（AMCl,with no antibacterial activity） by the biocathode communities were both markedly decreased. The acetate and ethanol yield from cathodophilic microbial glucose fermentation（with release of electrons） was also reduced. Formation of the product AMCl was enhanced by the biocathode dechloridation reaction compared with that produced from pure electrochemical or microbial dechloridation processes. The electrochemical and morphological analyses of cathode biofilms demonstrated that some cathodophilic microbes could adapt to low temperature and play a key role in CAP degradation. The resilient biocathode BES has a potential for the treatment of CAP-containing wastewater in temperature fluctuating environments.
基金supported by the National Natural Science Foundation of China (Nos. 21275084 and 41476083)Doctoral Foundation of the Ministry of Education of China (No. 20113719130001)+1 种基金Scientific and Technical Development Project of Qingdao (No. 12-1-4-3-(23)-jch)Outstanding Adult-Young Scientific Research Encouraging Foundation of Shandong Province (No. BS2012CL013)
文摘In this study, we synthesized molybdenum disulfide/polyaniline（MoS2/PANI） nanocomposite via in situ polymerization of aniline in the presence of thin-layered MoS2. The as-prepared MoS2/PANI nanocomposite obtained an improved electrochemical performance due to the physisorption interaction between aromatic aniline and the basal plane of MoS2. Furthermore, we constructed a new kind of electrochemical sensor based on MoS2/PANI nanocomposite for the detection of chloramphenicol, which showed an excellent performance. The sensor has a high sensitivity and wide detection range from 1 ×10^（-7）mol/L to 1×10^（-4）mol/L, with a low detection limit of 6.9 × 10^（-8）mol/L.
基金Supported by the Natural Science Foundation of Guangdong Province （5300978） and Zhongkai University of Agriculture and Engineering （G2360221）.
文摘In this article, poly（2-hydroxyethylmethacrylate-co-acrylamide） hydrogels were synthesized by bulk free-radical copolymerization of 2-hydroxyethylmethacrylate （HEMA） and acrylamide （AAm） for soft contact lens（SCL）-based ophthalmic drug delivery system. The copolymer was characterized with FT-IR and SEM, the swelling property of the hydrogels were studied by gravimetrical method, and chloramphenicol was used as a model drug to investigate drug release profile of the hydrogels. The results showed that poly（2-hydroxyethylmethacrylateco-acrylamide） hydrogels were transparent and useful SCL biomaterial, the water content increased as AAm content increase and pH decrease, and in the same way, hydrogel composition affected chloramphenicol release process too. Migration rate of chloramphenicol increased as the AAm content in the hydrogels increased in the first stage of diffusion process, whereas there was no significant difference thereafter.
基金supported by the National Natural Science Foundation of China(No.21227006)the Research Fund for the Doctoral Program of Higher Education(No.20110002110052)
文摘hloramphenicol is an antibiotic and one of the potential contaminants in honey.Solid-phase extraction is the key pretreatment procedure for analysis of chloramphenicol in honey.In this work,an on-line pretreatment liquid chromatography-tandem mass spectrometer system for sensitive,reliable and higher throughput analysis was developed.With the methylcellulose-immobilized reversed-phase column,sugars in a honey sample were efficiently removed in 1 min.As a result,the limit of quantitation of chloramphenicol was 20 pg/mL（0.2 μg/kg honey）.
文摘[ Objective] This study was conducted to establish a new UPLC-MS method for simultaneous detection of sulfonanfides and chloramphenicols in honey. [ Method] In this experiment, 0.2% formic acid-acetonitrile was used as an extractant to simultaneously extract chloramphenicoJs and sulfonamides from drugs. The extract was then loaded and extracted with an efficient separation column Oasis PRIME HLB. After nitrogen blow-concentration and dissolution with mobile phase, the extract was loaded on UPLC and detected by MS. [ Resultl There was a good linear relation in the range of 0. 1 - 10 ng/ml for chloramphenicols, with a correlation coefficient of 0.991, while sulfonamides had a good linear relation in the range of 0.5 - 50 ng/ml. The lowest detection limit of chloramphenicols and sulfonamides were 0. 1 and 0.5 μg/kg, respectively. The recoveries were in the range of 82.50% - 101.2%, with RSD values in the range of 3.2% -4.0%. [ Conclusion] This method is simple and fast with low detection limit, high recovery and good reproducibility, and could be used for simultaneous detection of re- sidual chloramphenicols and sulfonamides in honey. Key words UHPLC-MS; Sulfonamides ; Chloramphenicols ; Honey
基金Project supported by the National Natural Science Foundation of China(Grant Nos.40973073,40830744)the Shanghai Leading Academic Discipline Project(Grant No.S30109)+1 种基金the National Key Technology Research and Development Program in the 11th Five Year Plan of China(Grant Nos.2008BAC32B03,2009BAA24B04)the Natural Science Foundation of Shanghai Municipality(Grant Nos.09ZR1411300,09XD1401800)
文摘The purpose of this study was to evaluate the potential of electron beam to decompose chloramphenicol （CAP） in aqueous solutions. At the absorbed dose of 15 kGy, the decomposition rate of CAP was 95.24%. The degradation of CAP under electron beam irradiation followed pseudo-first-order kinetics. Redox reactions of CAP aqueous solutions with hydroxyl radicals （.OH）, hydrated electrons （eaq） and hydrated atoms （·H） were studied. The increase of the additives would result in the decrease of the degradation efficiency. The concentration of Cl- and NO3- in aqueous solution increased after electron beam irradiation. On the basis of the experimental results, a photocatalytic mechanism was discussed. The rate constant for reactions of .OH and CAP was 9.36×10^7 L/（mol.s） and for reaction of eaq and CAP was 7.33×10^7 L/（mol.s）..OH was supposed to play the key role in the radiation system of aqueous solution. Other free radicals like eaq and .H could also initiate the degradation.
基金the financial support provided by the National Key R&D Program of China (Nos.2020YFC1808401 and 2020YFC1808403)National Natural Science Foundation of China (Nos.22078213, 21938006 and 51973148)+3 种基金Basic Research Project of Cutting-Edge Technology in Jiangsu Province (No.BK20202012)Prospective Application Research Project of Suzhou (No.SYC2022042)Water Research and Technology Project of Suzhou (No.2022006)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘Waste polyolefin plastics, accounting for 50% of all plastic waste, represent a tremendously unexploited carbon source. Efficiently upcycling polyolefin waste into value-added carbon materials for waste water treatment avoiding using noble metals is challenging but economically and environmentally sustainable. In this work, MAX-Ti_(3)AlC_(2) supported Fe selectively catalyzes polyolefin into few-layered graphene in 5 min under microwave treatment. Graphene and MAX supported Fe(Fe@MLC) can completely(99.9%)degrade chloramphenicol(CAP) within 60 min, retain robust after 10 cycles and work efficiently at a wide p H range(3.87–13.03), avoiding the usage of noble metal. Moreover, the electrochemical active surface area(ECSA) of Fe@MLC is 2.7 times higher than that of commercial Pt/C. This work provides a cheap and efficient catalyst that promotes deconstruction of plastic wastes and indirectly degrades antibiotics thereby realizes the treatment of waste water with waste plastic.
基金supported by the National Natural Science Foundation of China (No.31270620)the Dalian Scientific and Technological Innovation Foundation (No.2018J12SN072)。
文摘BiOI/ZnO/rGO(reduced graphene oxide) composite photocatalyst was fabricated using a simple one-step hydrothermal process and applied to the degradation of antibiotic chloramphenicol(CAP). By tuning the Bi/Zn ratios, the structure and photoelectric properties of the catalyst were investigated and characterized in terms of their morphological, structural, optical and photoelectrochemical properties. The as-synthesized composite photocatalysts are well-crystalline, uniform dispersion and exhibit good photocatalytic properties.The photocatalytic degradation rate of CAP by BiOI/ZnO/rGO composite is 8.1 times and 1.8times that of BiOI and ZnO, respectively. The photocatalytic mechanism studies revealed that the synergistic effect between rGO and BiOI/ZnO can effectively separate photogenerated electron–hole, enhance photocurrents and conductivity, and improve charge carrier densities. Moreover, BiOI/ZnO/rGO possesses good stability and reusability that the degradation efficiency remained above 80% even after 5 recycling. This study reveals that both the introduction of rGO and heterostructure construction between BiOI and ZnO play a crucial role in their photoelectrochemical and photocatalytic properties.
基金Supported by the National Natural Science Foundation of China ( No. 30500384)the High Technology Research and Development Programme of China (No. 2006AA09Z431)
文摘A new,simple,rapid microbial assay was put forward for the detection of chloramphenicol(CAP)residues in Turbot muscles using luminescent bacteria DB(Photobacterium phosphoreum)as test organ-ism.By the luminescence inhibition of DB,the concentrations of CAP were determined.CAP spiked inTurbot muscle tissues ranging from 0.5 to 100μg/kg was extracted using ethyl acetate and hexane.Themethod had a good recovery of 93.69% with a minimum detection limit of 0.65μg/kg.It can be per-formed within 30min following simple extraction.The method therefore proved to be advantageous overchromatographic procedures as it was inexpensive,quite sensitive and can be adopted for rapid screeningof CAP in Turbot tissues.
文摘Objective:To evaluate the antibacterial activity of Ocimum sanctum(O.sanctum) leaf extract, alone,and in combination with chloramphenicol(C) and trimethoprim(Tm) against Salmonella enterica serovar Typhi(S.typhi).Methods:The antibacterial activity of ethanolic extract of tulsi, 0.sanctum,leaf(TLE:500μg) for 23 S.typhi isolates was determined following agar diffusion. The C(30μg) and Tm(5μg) activity alone and in combination with TLE(250μg) was determined by disk diffusion.The zone diameter of inhibition(ZDI) for the agents was recorded, and growth inhibitory indices(Glls) were calculated.Results:The S.typhi isolates(n=23),which were resistant to both C(ZDI 6 mm) and Tm(ZDI 6 mm),had TLE(500μg) ZDIs 16-24 mm.The ZDIs of C and Tm were increased up to 15-21 mm and 17-23 mm,respectively,when TLE(250μg) was added to the C and Tm discs.The Glls ranged 0.789-1.235 and 0.894-1.352,due to combined activity against S.typhi isolates,of C and TLE and Tm and TLE.respeclivelv.Conclusions:The data suggest that TLE,in combination with C and Tm,had synergistic activity for S.typhi isolates, and hence O.sanclum is potential in combating S.typhi drug resistance,as well promising in the development of non-antibiotic drug for S.typhi infection.
文摘Objective: To investigate the roles of chloramphenicol (CAP) preconditioning in the oxidative respiratory function of cerebral mitochondria in rats exposed to acute hypoxia during acute hypoxia by observing the changes of mitochondrial oxidative respiratory function and cytochrome C oxidase (COX) activity. Methods: Adult male Wistar rats were randomly divided into 4 groups: control (C), medication (M), hypoxia (H), and medication plus hypoxia (MH). Rats in groups M and MH were administered by peritoneal injection of CAP (50 mg/kg) every 12 h for 7 d before decapitation, but those in groups H and MH were exposed to a hypobaric chamber simulating 5 000 m high altitude for 24 h. The rat cerebral cortex was removed and mitochondria were isolated by centrifugation. Mitochondrial respiratory function and COX activity were measured by Clark oxygen electrode. Results: Compared with Group C, Group H showed significantly elevated state 4 respiration (ST 4), decreased state 3 respiration (ST 3), and respiratory control rate (RCR) in mitochondrial respiration during acute hypoxic exposure. ST 3 in Group MH was significantly lower than that in Group C, but was not significantly different from that in Groups H and M, while ST 4 in Group MH was significantly lower than that in groups C and H. RCR in Group MH was higher than that in Group H, but lower than that in Group C. COX activity in Group H was significantly lower than that in Group C. In Group MH, COX activity increased and was higher than that in Group H, but was still lower than that in Group C. Conclusion: Acute hypoxic exposure could lead to mitochondrial respiratory dysfunction, suggesting that CAP preconditioning might be beneficial to the recovery of rat respiratory function. The change of COX activity is consistent with that of mitochondrial respiratory function during acute hypoxic exposure and CAP-administration, indicating that COX plays an important role in oxidative phosphorylation function of mitochondria from cerebral cortex of hypoxic rats.
文摘[Objectives]To observe and analyze the clinical efficacy and possible mechanism of Chuanbai antipruritic lotion"water film"wet compress combined with chloramphenicol prednisone liniment in the treatment of acute eczema.[Methods]A total of 76 acute eczema cases admitted to Shiyan Taihe Hospital from January 2022 to March 2023 were divided into Western medicine treatment group and integrated traditional Chinese and Western medicine group.In the Western medicine treatment group,chloramphenicol and prednisone liniment was applied to the skin lesions and oral administration of cetirizine hydrochloride.The course of treatment in both groups was 2 weeks(w).The levels of interferon-γ(IFN-γ),interleukin-4(IL-4)and the ratio of IFN-γ/IL-4 in the peripheral blood of patients before and 2 weeks after treatment,as well as serum immunoglobulin E(IgE),anti-IgE antibody and histamine(HA)level,and with skin lesions disappearing time,skin oil,transepidermal water loss(TEWL),eczema area and severity index(EASI)score,total effective rate,degree of pruritus and traditional Chinese medicine quality of life scale(EPQOLS)score to evaluate the efficacy.[Results]Compared with the Western medicine treatment group at 2 w,the disappearance time of skin lesions in the integrated traditional Chinese and Western medicine group was shortened,TEWL,itching degree and EASI score,serum IgE and HA,and peripheral blood IL-4 levels were all decreased(P<0.05).IFN-γand IFN-γ/IL-4 ratio,anti-IgE antibody,EPQOLS score and total effective rate were all increased(P<0.05),and the difference was statistically significant.[Conclusions]Chuanbai antipruritic lotion"water film"wet compress combined with chloramphenicol prednisone liniment is an optimized and safe and efficient method for the treatment of acute eczema,which can quickly relieve the symptoms of inflammatory damage of eczema and restore the skin barrier function,dry dampness and relieve itch.Inhibition of the release of histamine active substances and regulation of immunity may be the main mechanisms.
文摘Purpose: While there were numerous clinical examples of ocular damage, the histopathology of retinal responses was poorly characterized, and animal model research was limited. The consequences of retinal lesions with traditional medicine treatment were mostly unknown. In this work, goldfish was employed as a model for penetrating injury of the eyes to study the ocular trauma with antibiotic and traditional medicine treatments. Materials and Methods: The penetration of the eyes was performed at 2mm above the midline of the limbus in the superior quadrant with an 18-gauge sterile needle, all the way to the retina but avoiding the lens while the animals were anaesthetized in water containing 100 mg/L ethyl 3-aminobenzoate methanesulfonate (MS-222). The animals were divided into three groups and received treatments of saline, chloramphenicol, and Angong Niuhuang pill (Angong) eyedrops twice a day respectively. Angong after seven days, the animals were sacrificed. Immunohistochemical evaluation of proliferative cell nuclear antigen (PCNA), brain-derived neurotrophic factor (BDNF), catalase, and cleaved caspase-3, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) for apoptotic cells were performed on the fish’s superior quadrants of the retinae. The whole experiment was repeated two times. Result: It was evident that both the retinae treated with chloramphenicol and Angong had fewer apoptotic cells and more proliferative cells, particularly in the cases of the Angong treatment. BDNF was in the inner nuclear layer and ganglion cell layer of all groups. In the chloramphenicol and Angong groups, some cells in the outer nuclear layer displayed BDNF. Catalase reactions confirmed equivalent findings that the treated retinae with chloramphenicol or Angong treatment had less catalase. Conclusion: Angong Niuhuang pill is a traditional medicine composite formula with antibiotic and neuroprotective effects on the brain and the eyes, and this work also pointed out its possible pharmaceutical potential.
文摘The aim is to evaluate the effect of ciprofloxacin and chloramphenicol on anti-BSA antibody production triggered by bovine albumin encapsulated in non-ionic surfactant vesicle,niosomes.Reverse phase evaporation method was adopted to entrap the antigen in colloidal carrier composed of Span 80 and Span 85 followed by simultaneous characterization for particle size,entrapment efficiency and in vitro release.The protein content was determined by Bradford method using UV Visible Spectrophotometer at 595 nm.Humoral immune response was measured in terms of systemic IgG antibody titre by ELISA method.Experimental data indicated that 7∶3 molar ratio of Span 80 and cholesterol based niosomal formulation possessed maximum(39.8±2.9)% of soluble protein.Ciprofloxacin markedly(P<0.05) decreased the antibody titre.In contrast,chloramphenicol did not reduce the antibody titre significantly in comparison to control group(P>0.05).It is necessary to explore the effect of a vaccine antigen when a candidate is medicated with a therapeutic agent,which might help in programming a new drug management and vaccination programme.
基金National Key R&D Program of China(No.2021YFC3200602)the Key Research and Development Program of Ningxia Hui Autonomous Region of China(No.2023BEG02053)the Shanghai Chengtou Water Group Co.Ltd.Scientific Research Reserve Project(No.KY.WB.23.001).
文摘Conventional wastewater treatment facilities lack the appropriate design to abate the presence of antibiotics,which are potential hazards in natural water sources.The use of electroactive bacteria and biochar to eliminate antibiotics has been reported;however,the impact and underlying mechanisms by which biochar enhances the biodegradation of antibiotics by electroactive microorganisms remain unclear.As chloramphenicol exhibits a high degree of toxicity to aquatic organisms,this study investigated the synergistic effect of biochar on the biodegradation of chloramphenicol by electroactive Shewanella oneidensis MR-1.Biochar significantly improved chloramphenicol degradation rates from 36.05%to 70.79%within 24 h by promoting electron transfer processes in S.oneidensis MR-1,a typical electroactive microorganism.This study offers unique insights into the electrochemical properties of biochar,particularly those influenced by pyrolysis temperature,in enhancing the microbial electron transfer processes.Furthermore,the findings demonstrated that biochar not only promotes the growth and activity of electroactive bacteria but also facilitates direct and indirect electron transfer mechanisms,leading to significantly improved antibiotic degradation rates.In summary,biochar is a novel perspective in environmental biotechnology that offers an innovative approach to address the challenge of persistent antibiotics in wastewater treatment.
基金supported by the Postdoctoral Science Foundation of China(Grant No.2018M632735)the National Natural Science Foundation of China(Grant Nos.91751112,and 41573071)+2 种基金the Senior User Project of RV KEXUE(Grant No.KEXUE2018G01)the Natural Science Foundation(Grant No.JQ201608)the Young Taishan Scholars Program(Grant No.tsqn20161054)of Shandong Province
文摘Geobacter metallireducens is known to be capable of removing nitroaromatic compounds via an oxidation mode. However, little attention has been paid to investigate the reductive removal of chlorinated nitroaromatic compounds by G. metallireducens. In this study, G. metallireducens was used to reduce chloramphenicol(CAP), a typical chlorinated nitroaromatic antibiotic. Cyclic voltammograms and chronoamperometry highlighted a higher peak current for CAP reduction by G. metallireducens compared to the control without bacteria. G. metallireducens efficiently reduced CAP(20 mg/L) with acetate as the sole electron donor, and the removal efficiency reached(97.6±4.9)% within 6 d. Aromatic amine(AMCl2), AMCl(dechlorinated AMCl2) and AM(dechlorinated AMCl) were identified as reduction products by liquid chromatography-mass spectrometry. However, the removal efficiency declined to(25.0±3.6)% when the CAP dosage increased to 80 mg/L. Transcriptomic analysis indicated the significant upregulation of genes related to electron transfer, such as pilus assembly protein gene(2.8 folds), NADH-quinone oxidoreductase subunit K2 gene(4.5 folds) and many c-type cytochrome genes such as cytochrome c biogenesis protein Res B(Gmet 2901, 4.6 folds), cytochrome c(Gmet 0335, 4.4 folds) and cytochrome c7(Gmet 2902, 3.4 folds). Furthermore, a gene related to chlorinated contaminant removal(Gmet 1046, 5.4 folds) was also upregulated, possibly resulting in enhanced CAP reduction. This work deepened our knowledge of the bioremediation ability of G. metallireducens with respect to environmental contaminants and provided a potential strategy to treat antibiotics with electrochemically active bacteria.
