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1.
Water Res ; 203: 117488, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34482236

RESUMO

The biodegradability of the anticonvulsant pregabalin (PGB) was studied in laboratory incubation experiments in contact with water/sediment systems under different redox conditions. PGB was degraded by biological processes under aerobic conditions reaching half-lives of 8 to 10 d, while inactivated and anaerobic control experiments revealed no significant decrease of PGB concentrations. Within experiments spiked with elevated PGB concentrations, 12 TPs were formed and tentative chemical structures could be proposed by accurate masses and fragmentation pathways detected via measurements with high resolution mass spectrometry (LC-QToF-MS). Four of the proposed TPs were finally confirmed either by authentic reference standards (PGB-Lactam, ISA, TP 157-A (II)) or a self-synthesized standard (NA-PGB). PGB-Lactam was identified as the quantitatively most relevant TP formed via intramolecular cyclization under aerobic conditions, reaching up to 33% of the initial PGB concentration. Incubation experiments spiked with PGB-Lactam revealed three times higher half-lives compared to the parent compound, indicating that PGB-Lactam is more stable than PGB. A comparison with results gained from water/sediment incubation experiments with the structurally related compound gabapentin (GBP) revealed, that the transformation behaviour can be mainly extrapolated to PGB. Most of the observed transformation reactions found for PGB were comparable to the ones found for GBP. The TPs PGB-Lactam and NA-PGB as well as three GBP TPs (GBP-Lactam, NA-GBP and CCHA) have been detected in German wastewater treatment plants (WWTPs) effluents and the river Rhine including some of its tributaries such as Main, Neckar, Moselle and Aare. Moreover, GBP and PGB as well as some of their TPs were detected in German bank filtrates and finished drinking waters up to 260 ng L-1. For that reason these compounds should be monitored in drinking water in the future.


Assuntos
Poluentes Químicos da Água , Água , Biotransformação , Gabapentina , Pregabalina , Rios , Águas Residuárias , Poluentes Químicos da Água/análise
2.
Braz J Biol ; 83: e253009, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495170

RESUMO

Today, global focus of research is to explore the solution of energy crisis and environmental pollution. Like other agricultural countries, bulk quantities of watermelon peels (WMP) are disposed-off in environment as waste in Pakistan and appropriate management of this waste is the need of hour to save environment from pollution. The work emphasizes the role of ethanologenic yeasts to utilize significant sugars present in WMP for low-cost bioethanol fermentation. Dilute hydrochloric acid hydrolysis of WMP was carried out on optimized conditions employing RSM (response surface methodology) following central composite design (CCD). This experimental design is based on optimization of ethanologenesis involving some key independent parameters such as WMP hydrolysate and synthetic media ratio (X1), incubation temperature (X2) and incubation temperature (X3) for maximal ethanol yield exploiting standard (Saccharomyces cerevisiae K7) as well as experimental (Metchnikowia cibodasensisY34) yeasts. The results revealed that maximal ethanol yields obtained from S. cerevisiae K7 was 0.36±0.02 g/g of reducing sugars whereas M. cibodasensisY34, yielded 0.40±0.01 g ethanol/g of reducing sugars. The yeast isolate M. cibodasensisY34 appeared as promising ethanologen and embodies prospective potential for fermentative valorization of WMP-to-bioethanol.


Assuntos
Cucurbitaceae , Etanol , Biotransformação , Fermentação , Estudos Prospectivos , Saccharomyces cerevisiae , Água
3.
Enzyme Microb Technol ; 150: 109892, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34489045

RESUMO

Cell-free synthesis has been adopted in the bioconversion process due to its known advantages, such as fast production rate, high product content, and no substrate/product inhibition effect. In this study, the cell-free supernatant of Pseudomonas aeruginosa was used to improve the production of 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) from oleic acid. DOD production using cell-free supernatant demonstrated reduction in bioconversion duration and higher product concentration than conventional method using whole cell culture. The maximum DOD concentration (6.41 g/L) was obtained after 36 h of biotransformation using 1 % v/v oleic acid as a substrate with a productivity of 0.178 g/L/h and a yield of 74.8 %. DOD concentration, productivity, and yield using cell-free supernatant were 2.12, 7.12, and 2.22 times higher, respectively, than using the conventional whole cell culture method. Of the carbon and nitrogen sources used in pre-culture, galactose and sodium glutamate along with diammonium phosphate were found to be the most effective for DOD production. An incubation temperature of 27 °C and pH 8.0 were found to be most favorable for DOD production. In addition, sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis demonstrated the presence of enzymes related to DOD production in the cell-free supernatant, which was substantiated by performing DOD production experiment using the supernatant enzymes extracted from protein gel bands with oleic acid as a substrate. To the best of our knowledge, this is the first report on DOD production using a cell-free supernatant and verifying the existence of the relevant enzymes in the cell-free supernatant. Compared to whole cell process, cell-free DOD production holds several advantages, including higher DOD productivity which could be beneficial for large-scale production.


Assuntos
Ácido Oleico , Pseudomonas aeruginosa , Biotransformação , Nitrogênio , Ácidos Oleicos
4.
Food Res Int ; 147: 110470, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399468

RESUMO

Lactic acid bacteria have been reported to be capable of converting polyunsaturated fatty acids, e.g. linoleic acid (LA) into bioactive and other fatty acid metabolites that are not toxic to the bacteria themselves, but the mechanism of this conversion is not clear. Here we reported for the first time that probiotic L. plantarum 12-3 derived from Tibet kefir when supplemented with LA from 1% to 10% in the MRS medium transformed LA to various fatty acid derivatives. These derivatives formed in the medium were identified with gas chromatography and mass spectrometry. In silico studies were done to confirm the enzymatic reactions responsible for this conversion. We found that L. plantarum 12-3 could convert LA at different concentrations to 8 different fatty acid derivatives. Putative candidate enzymes involved in biotransformation of LA into fatty acid derivatives were identified via whole genome of L. plantarum 12-3, including linoleate isomerase, acetoacetate decarboxylase and dehydrogenase. Therefore, the present study provides further understanding of the mechanism of conversion of LA to health-beneficial fatty acid metabolites in probiotic L. plantarum, which can be explored for potential application in functional foods.


Assuntos
Lactobacillus plantarum , Biotransformação , Simulação por Computador , Cromatografia Gasosa-Espectrometria de Massas , Ácido Linoleico
5.
Appl Microbiol Biotechnol ; 105(16-17): 6515-6527, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34423412

RESUMO

Pharmaceuticals find their way to the aquatic environment via wastewater treatment plants (WWTPs). Biotransformation plays an important role in mitigating environmental risks; however, a mechanistic understanding of involved processes is limited. The aim of this study was to evaluate potential relationships between first-order biotransformation rate constants (kb) of nine pharmaceuticals and initial concentration of the selected compounds, and sampling season of the used activated sludge inocula. Four-day bottle experiments were performed with activated sludge from WWTP Groesbeek (The Netherlands) of two different seasons, summer and winter, spiked with two environmentally relevant concentrations (3 and 30 nM) of pharmaceuticals. Concentrations of the compounds were measured by LC-MS/MS, microbial community composition was assessed by 16S rRNA gene amplicon sequencing, and kb values were calculated. The biodegradable pharmaceuticals were acetaminophen, metformin, metoprolol, terbutaline, and phenazone (ranked from high to low biotransformation rates). Carbamazepine, diatrizoic acid, diclofenac, and fluoxetine were not converted. Summer and winter inocula did not show significant differences in microbial community composition, but resulted in a slightly different kb for some pharmaceuticals. Likely microbial activity was responsible instead of community composition. In the same inoculum, different kb values were measured, depending on initial concentration. In general, biodegradable compounds had a higher kb when the initial concentration was higher. This demonstrates that Michealis-Menten kinetic theory has shortcomings for some pharmaceuticals at low, environmentally relevant concentrations and that the pharmaceutical concentration should be taken into account when measuring the kb in order to reliably predict the fate of pharmaceuticals in the WWTP. KEY POINTS: • Biotransformation and sorption of pharmaceuticals were assessed in activated sludge. • Higher initial concentrations resulted in higher biotransformation rate constants for biodegradable pharmaceuticals. • Summer and winter inocula produced slightly different biotransformation rate constants although microbial community composition did not significantly change.


Assuntos
Preparações Farmacêuticas , Poluentes Químicos da Água , Biotransformação , Cromatografia Líquida , RNA Ribossômico 16S/genética , Esgotos , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise
6.
Chemosphere ; 277: 130254, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34384174

RESUMO

Liver S9 fractions from common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) were incubated with seven pesticides (fenamidone, fenoxaprop-p-ethyl, penflufen, spirotetramat, tebuconazole, tembotrione and trifloxystrobin) and the metabolic pathways of the applied chemicals were determined by HPLC-high-resolution mass spectrometry. Five of the seven pesticides (fenamidone, penflufen, spirotetramat, trifloxystrobin and fenoxaprop-p-ethyl) revealed a higher metabolic capacity of rainbow trout liver fractions compared to carp liver fractions. The other two pesticides (tebuconazole and tembotrione) showed a similar and marginal biotransformation for liver S9 fractions of both species. Furthermore, four compounds (penflufen, spirotetramat, tembotrione and tebuconazole) were incubated with cryo-preserved hepatocytes of rainbow trout showing additional conjugated metabolites compared to liver S9 fractions. The incubations were performed with concentrations of 1 and 10 µM for experiments with liver S9 fractions and 5 µM with hepatocytes for up to 120 (liver S9 fractions) or 240 min (hepatocytes). A set of positive controls was used to confirm the metabolic capability of the in vitro systems. The comparison of the in vitro results from hepatocyte assays of penflufen and tebuconazole with the data from corresponding in vivo studies performed according to OECD (Organisation for Economic Co-operation and Development) guideline 305 exhibited a similar metabolic behavior for these pesticides and emphasizes the reliability of the in vitro assays. Besides investigation of the metabolism of plant protection products for research purposes, inter-species comparison by in vitro assays and the use of PBTK modelling approaches will allow improved environmental and dietary risk assessments.


Assuntos
Carpas , Oncorhynchus mykiss , Praguicidas , Animais , Biotransformação , Fígado/metabolismo , Praguicidas/metabolismo , Praguicidas/toxicidade , Reprodutibilidade dos Testes
7.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445678

RESUMO

Wogonin is one of the most active flavonoids from Scutellaria baicalensis Georgi (baikal skullcap), widely used in traditional Chinese medicine. It exhibits a broad spectrum of health-promoting and therapeutic activities. Together with baicalein, it is considered to be the one of main active ingredients of Chinese medicines for the management of COVID-19. However, therapeutic use of wogonin may be limited due to low market availability connected with its low content in baikal skullcap and lack of efficient preparative methods for obtaining this compound. Although the amount of wogonin in skullcap root often does not exceed 0.5%, this material is rich in wogonin glucuronide, which may be used as a substrate for wogonin production. In the present study, a rapid, simple, cheap and effective method of wogonin and baicalein preparation, which provides gram quantities of both flavonoids, is proposed. The obtained wogonin was used as a substrate for biotransformation. Thirty-six microorganisms were tested in screening studies. The most efficient were used in enlarged scale transformations to determine metabolism of this xenobiotic. The major phase I metabolism product was 4'-hydroxywogonin-a rare flavonoid which exhibits anticancer activity-whereas phase II metabolism products were glucosides of wogonin. The present studies complement and extend the knowledge on the effect of substitution of A- and B-ring on the regioselective glycosylation of flavonoids catalyzed by microorganisms.


Assuntos
Flavanonas/química , Flavanonas/farmacologia , Scutellaria baicalensis/química , Animais , Biotransformação , COVID-19/tratamento farmacológico , Flavanonas/isolamento & purificação , Flavanonas/farmacocinética , Fungos/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , SARS-CoV-2/efeitos dos fármacos
8.
Molecules ; 26(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206424

RESUMO

Determination of the metabolism pathway of xenobiotics undergoing the hepatic pass is a crucial aspect in drug development since the presence of toxic biotransformation products may result in significant side effects during the therapy. In this study, the complete hepatic metabolism pathway of dapoxetine established according to the human liver microsome assay with the use of a high-resolution LC-MS system was described. Eleven biotransformation products of dapoxetine, including eight metabolites not reported in the literature so far, were detected and identified. N-dealkylation, hydroxylation, N-oxidation and dearylation were found to be the main metabolic reactions for the investigated xenobiotic. In silico analysis of toxicity revealed that the reaction of didesmethylation may contribute to the increased carcinogenic potential of dapoxetine metabolites. On the other hand, N-oxidation and aromatic hydroxylation biotransformation reactions possibly lead to the formation of mutagenic compounds.


Assuntos
Benzilaminas , Simulação por Computador , Microssomos Hepáticos/química , Naftalenos , Benzilaminas/química , Benzilaminas/farmacocinética , Biotransformação , Cromatografia Líquida de Alta Pressão , Humanos , Naftalenos/química , Naftalenos/farmacocinética
9.
Sci Total Environ ; 794: 148650, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34198081

RESUMO

The present study aimed to clarify the effect of oxygen respiration on biotransformation of alternative electron acceptors (e.g., nitrate and sulfate) underlying the simultaneous removal of ammonium and sulfate in a single aerated sequencing batch reactor. Complete nitrification was achieved in feast condition, while denitrification was carried out in both feast and famine conditions when aeration intensity (AI) was higher than 0.22 L/(L·min). Reactors R1 [0.56 L/(L·min)], R2 [0.22 L/(L·min)], and R3 [0.08 L/(L·min)] achieved 72.39% sulfate removal efficiency in feast condition, but H2S release occurred in R3. Following exogenous substrate depletion, sulfate concentration increased again and exceeded the influent value in R1, indicating that sulfate transformation was affected by oxygen intrusion. Metagenomic analysis showed that a higher AI promoted sulfate reduction by switching from dissimilatory to assimilatory pathway. Lower AI-acclimated microorganisms (R3) produced H2S and ammonium, while higher AI-acclimated microorganisms (R1) accumulated nitrite, which confirmed that biotransformation of N and S was strongly regulated by redox imbalance driven by aeration. This implied that respiration control, a microbial self-regulation mechanism, was linked to the dynamic imbalance between electron donors and electron acceptors. Aerobic nitrate (sulfate) reduction, as one of the effects of respiration control, could be used as an alternative strategy to compensate for dynamic imbalance, when supported by efficient endogenous metabolism. Moderate aeration induced microorganisms to change their energy conservation and survival strategy through respiration control and inter-genus protection of respiratory activity among keystone taxa (including Azoarcus in R1, Thauera in R2, and Thiobacillus, Ottowia, and Geoalkalibacter in R3) to form an optimal niche in response to oxygen intrusion and achieve benign biotransformation of C, N, and S without toxic intermediate accumulation. This study clarified the biotransformation mechanism of ammonium and sulfate driven by aeration and provided theoretical guidance for optimizing existing aeration-based techniques.


Assuntos
Compostos de Amônio , Nitrogênio , Reatores Biológicos , Biotransformação , Desnitrificação , Metagenoma , Nitrificação , Esgotos , Sulfatos , Enxofre
10.
Toxicol Appl Pharmacol ; 426: 115639, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34256052

RESUMO

Polychlorinated biphenyls (PCBs) are endocrine disrupting chemicals with documented, though mechanistically ill-defined, reproductive toxicity. The toxicity of dioxin-like PCBs, such as PCB126, is mediated via the aryl hydrocarbon receptor (AHR) in non-ovarian tissues. The goal of this study was to examine the uterine and ovarian effects of PCB126 and test the hypothesis that the AHR is required for PCB126-induced reproductive toxicity. Female Holzman-Sprague Dawley wild type (n = 14; WT) and Ahr knock out (n = 11; AHR-/-) rats received a single intraperitoneal injection of either corn oil vehicle (5 ml/kg: WT_O and AHR-/-_O) or PCB126 (1.63 mg/kg in corn oil: WT_PCB and AHR-/-_PCB) at four weeks of age. The estrous cycle was synchronized and ovary and uterus were collected 28 days after exposure. In WT rats, PCB126 exposure reduced (P < 0.05) body and ovary weight, uterine gland number, uterine area, progesterone, 17ß-estradiol and anti-Müllerian hormone level, secondary and antral follicle and corpora lutea number but follicle stimulating hormone level increased (P < 0.05). In AHR-/- rats, PCB126 exposure increased (P ≤ 0.05) circulating luteinizing hormone level. Ovarian or uterine mRNA abundance of biotransformation, and inflammation genes were altered (P < 0.05) in WT rats due to PCB126 exposure. In AHR-/- rats, the transcriptional effects of PCB126 were restricted to reductions (P < 0.05) in three inflammatory genes. These findings support a functional role for AHR in the female reproductive tract, illustrate AHR's requirement in PCB126-induced reprotoxicity, and highlight the potential risk of dioxin-like compounds on female reproduction.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/deficiência , Disruptores Endócrinos/toxicidade , Bifenilos Policlorados/toxicidade , Receptores de Hidrocarboneto Arílico/deficiência , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Biotransformação/genética , Peso Corporal/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Hormônios/sangue , Tamanho do Órgão/efeitos dos fármacos , Ovário/efeitos dos fármacos , Ovário/metabolismo , Ovário/patologia , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Ratos Transgênicos , Receptores de Hidrocarboneto Arílico/genética , Reprodução/efeitos dos fármacos , Útero/efeitos dos fármacos , Útero/metabolismo , Útero/patologia
11.
Xenobiotica ; 51(9): 1081-1086, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34284691

RESUMO

1. Challenges and opportunities in the field of biotransformation were presented and discussed at the 1st European Biotransformation workshop which was conducted virtually in collaboration with the DMDG 27 January 2021. Here we summarize the presentations and discussions from this workshop.The following topics were covered:2. Needs for radiolabel for IND filing versus quantitation without standards.3. Applications of cyclic ion mobility in the field of biotransformation.4. Computational predictions of xenobiotic metabolism.5. Future (outsourcing) needs in biotransformation.6. Genotoxicity risk assessment of metabolites and qualification of impurities using metabolite data.7. Regulatory aspects of MIST.


Assuntos
Biotransformação , Inativação Metabólica
12.
Water Res ; 202: 117412, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34303164

RESUMO

For most micropollutants (MPs) present in surface waters, such as pesticides and pharmaceuticals, the contribution of biotransformation to their overall removal from lake ecosystems is largely unknown. This study aims at empirically determining the biotransformation rate constants for 35 MPs at different periods of the year and depths of a meso-eutrophic lake. We then tested statistically the association of environmental parameters and microbial community composition with the biotransformation rate constants obtained. Biotransformation was observed for 14 out of 35 studied MPs for at least one sampling time. Large variations in biotransformation rate constants were observed over the seasons and between compounds. Overall, the transformation of MPs was mostly influenced by the lake's temperature, phytoplankton density and bacterial diversity. However, some individual MPs were not following the general trend or association with microorganism biomass. The antidepressant mianserin, for instance, was transformed in all experiments and depths, but did not show any relationship with measured environmental parameters, suggesting the importance of specific microorganisms in its transformation. The results presented here contribute to our understanding of the fate of MPs in surface waters and thus support improved risk assessment of contaminants in the environment.


Assuntos
Lagos , Fitoplâncton , Bactérias , Biotransformação , Ecossistema , Estações do Ano , Temperatura
13.
Molecules ; 26(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202717

RESUMO

Timosaponin BII is one of the most abundant Anemarrhena saponins and is in a phase II clinical trial for the treatment of dementia. However, the pharmacological activity of timosaponin BII does not match its low bioavailability. In this study, we aimed to determine the effects of gut microbiota on timosaponin BII metabolism. We found that intestinal flora had a strong metabolic effect on timosaponin BII by HPLC-MS/MS. At the same time, seven potential metabolites (M1-M7) produced by rat intestinal flora were identified using HPLC/MS-Q-TOF. Among them, three structures identified are reported in gut microbiota for the first time. A comparison of rat liver homogenate and a rat liver microsome incubation system revealed that the metabolic behavior of timosaponin BII was unique to the gut microbiota system. Finally, a quantitative method for the three representative metabolites was established by HPLC-MS/MS, and the temporal relationship among the metabolites was initially clarified. In summary, it is suggested that the metabolic characteristics of gut microbiota may be an important indicator of the pharmacological activity of timosaponin BII, which can be applied to guide its application and clinical use in the future.


Assuntos
Microbioma Gastrointestinal/efeitos dos fármacos , Saponinas/farmacocinética , Esteroides/farmacocinética , Animais , Biotransformação , Masculino , Ratos , Ratos Sprague-Dawley , Saponinas/farmacologia , Esteroides/farmacologia
14.
Sci Total Environ ; 796: 148927, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34271385

RESUMO

This study aimed to investigate the biotransformation of ZnO nanoparticles (NPs) in maize grown in hydroponics for ecotoxicity assessment. Maize seedlings grown for 14 days were exposed to a solution of 9 nm ZnO NPs, 40 nm ZnO NPs, and ZnSO4 at a Zn concentration of 300 mg L-1 for 1, 3, and 7 days, respectively. The results of in-situ Zn distribution in maize (Zea mays) showed that 9 nm ZnO NPs could quickly enter the roots of maize and reach the center column transport system of the stem. The results of transmission electron microscopy combined with energy dispersive X-ray spectroscopy revealed that ZnO NPs were accumulated in the vacuoles of the roots, and then transformed and transported through vesicles. Simulated studies showed that low pH (5.6) played a critical role in the transformation of ZnO NPs, and organic acids (Kf = 1011.4) could promote particle dissolution. Visual MINTEQ software simulated the species of Zn after the entry of ZnO NPs or Zn2+ into plants and found that the species of Zn was mainly Zn2+ when the Zn content of plants reached 200-300 ppm. Considering that the lowest Zn content of the roots in treatments was 1920 mg kg-1, combination of the result analysis of root effects showed that the toxicity of roots in most treatments had a direct relationship with Zn2+. However, treatment with 9 nm ZnO NPs exhibited significantly higher toxicity than ZnSO4 treatment on day 1 when the Zn2+ concentration difference was not significant, which was mainly due to the large amount of ZnO NPs deposited in the roots. To the authors' knowledge, this study was the first to confirm the process of biotransformation and explore the factors affecting the toxicity of ZnO NPs in depth.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Óxido de Zinco , Biotransformação , Nanopartículas Metálicas/toxicidade , Nanopartículas/toxicidade , Raízes de Plantas , Zea mays , Óxido de Zinco/toxicidade
15.
J Environ Manage ; 296: 113152, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34217942

RESUMO

Anaerobic digestion (AD) comprises a series of biochemical reactions, with methane as one of the target products. Amino acids (AAs) are important molecular and primary intermediate products when protein is the main component of organic waste/wastewater. The L (levorotatory, left-handed)-configuration is natural for AAs, while D (dextrorotatory, right-handed) -AAs also widely exist in the natural environment and can be generated by racemization. However, the effects and underlying mechanisms of natural AAs and their enantiomers on the methane yield and the underlying mechanisms remain unclear. In this study, the effects of certain widespread L-AAs and their enantiomers on two-stage AD and the mechanisms therein were investigated. The AAs enantiomers showed variable or even opposite effects on different processes. The methane yield from a model monosaccharide (glucose) decreased by 57% with D-leucine addition. The butyrate generation and the methane yield from propionate were sensitive to the AA configuration and were inhibited by D-leucine by 80% and 61.8%, respectively, with D-leucine addition, while the volatile fatty acids concentration was slightly increased with the addition of L-leucine. The related mechanisms were further investigated in terms of key enzymes and microbial communities. The addition of D-Leucine decreased acetic acid production from homoacetogens by 30.2% due to the inhibition of key enzymes involved in hydrogen generation and consumption. The transform of butyryl CoA to butyryl phosphate was the rate-limiting step, with the related enzyme (phosphotransbutylase) was inhibited by D-leucine. Furthermore, the bacteria related to butyric acid generation and organic matter degradation were inhibited by D-leucine, while the methanogenic archaea remained stable irrespective of leucine addition. The effect of D-AAs on microorganisms is related to the type of sludge. In this study, the methanogenetic seed sludge was granular and did not dissociate after treatment; however, the D-AAs could trigger biofilm disassembly and reduce the stability of the sludge floc. The study provides a novel method for regulating AD by adding specific AAs with L or D configuration.


Assuntos
Reatores Biológicos , Metano , Aminoácidos , Anaerobiose , Biotransformação , Ácidos Graxos Voláteis , Esgotos
16.
J Environ Manage ; 297: 113195, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34280855

RESUMO

Phosphogypsum (PG) is a waste by-product of phosphate fertilizer industry, produced in huge amount during the manufacture of phosphoric acid by economic wet process. Assessment of PG toxicity on soil has been poorly emphasized, therefore an efficient methods needs to be adopted to assess its toxic effect on soil fertility. We also need an effective eco-technological strategies for better waste PG management in order to improve the environmental health. The present study aimed to investigate the impact of PG toxicity on fertile soil and utilization of indigenous microorganisms for aerobic detoxification of PG contaminated soil to evaluate the scope for biostimulation based in situ bioremediation. In this study it is evident that application of PG to fertile soil in certain concentration results highly acidic, sulfate rich, aerobic environment, thus severely weakens the metabolic activity of the indigenous microorganisms. This investigation via microcosm based study further evaluated the intrinsic biotransformation ability of these microorganisms and found that was enhanced significantly (>95% reduction in sulfate concentration in 180 days) with carbon, nitrogen and phosphate amendments. Community level physiological profiling analyses indicated distinct shift in metabolic abilities following carbon amendments. Our study for the first time may help to formulate a strategy in aerobic biotransformation of PG contaminated soil environment, yet appreciable rate by supplying adequate nutrients.


Assuntos
Poluentes do Solo , Solo , Biodegradação Ambiental , Biotransformação , Sulfato de Cálcio , Fósforo , Poluentes do Solo/análise , Tecnologia
17.
Aquat Toxicol ; 237: 105901, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34198209

RESUMO

Arsenic is a toxic metalloid that is widely distributed in the environment due to its persistence and accumulative properties. The occurrence, distribution, and biological effects of arsenic in aquatic environments have been extensively studied. Acute and chronic toxicities to arsenic are associated with fatal effects at the individual and molecular levels. The toxicity of arsenic in aquatic organisms depends on its speciation and concentration. In aquatic environments, inorganic arsenic is the dominant form. While trivalent arsenicals have greater toxicity compared with pentavalent arsenicals, inorganic arsenic can assume a variety of forms through biotransformation in aquatic organisms. Biotransformation mechanisms and speciation of arsenic have been studied, but few reports have addressed the relationships among speciation, toxicity, and bioavailability in biological systems. This paper reviews the modes of action of arsenic along with its toxic effects and distribution in an attempt to improve our understanding of the mechanisms of arsenic toxicity in aquatic organisms.


Assuntos
Arsênio , Arsenicais , Poluentes Químicos da Água , Organismos Aquáticos , Arsênio/toxicidade , Biotransformação , Poluentes Químicos da Água/toxicidade
18.
Methods Mol Biol ; 2342: 481-550, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34272705

RESUMO

The efficacy, safety, and tolerability of drugs are dependent on numerous factors that influence their disposition. A dose that is efficacious and safe for one individual may result in sub-therapeutic or toxic blood concentrations in others. A significant source of this variability in drug response is drug metabolism, where differences in presystemic and systemic biotransformation efficiency result in variable degrees of systemic exposure (e.g., AUC, Cmax, and/or Cmin) following administration of a fixed dose.Interindividual differences in drug biotransformation have been studied extensively. It is recognized that both intrinsic factors (e.g., genetics, age, sex, and disease states) and extrinsic factors (e.g., diet , chemical exposures from the environment, and the microbiome) play a significant role. For drug-metabolizing enzymes, genetic variation can result in the complete absence or enhanced expression of a functional enzyme. In addition, upregulation and downregulation of gene expression, in response to an altered cellular environment, can achieve the same range of metabolic function (phenotype), but often in a less predictable and time-dependent manner. Understanding the mechanistic basis for variability in drug disposition and response is essential if we are to move beyond the era of empirical, trial-and-error dose selection and into an age of personalized medicine that will improve outcomes in maintaining health and treating disease.


Assuntos
Família 4 do Citocromo P450/genética , Preparações Farmacêuticas/metabolismo , Variantes Farmacogenômicos , Biotransformação , Regulação da Expressão Gênica , Humanos , Inativação Metabólica , Medicina de Precisão
19.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206260

RESUMO

Although manure is an important source of minerals and organic compounds it represents a certain risk of spreading the veterinary drugs in the farmland and their permeation to human food. We tested the uptake of the anthelmintic drug fenbendazole (FBZ) by soybean, a common crop plant, from the soil and its biotransformation and accumulation in different soybean organs, including beans. Soybeans were cultivated in vitro or grown in a greenhouse in pots. FBZ was extensively metabolized in roots of in vitro seedlings, where sixteen metabolites were identified, and less in leaves, where only two metabolites were found. The soybeans in greenhouse absorbed FBZ by roots and translocated it to the leaves, pods, and beans. In roots, leaves, and pods two metabolites were identified. In beans, FBZ and one metabolite was found. FBZ exposure did not affect the plant fitness or yield, but reduced activities of some antioxidant enzymes and isoflavonoids content in the beans. In conclusion, manure or biosolids containing FBZ and its metabolites represent a significant risk of these pharmaceuticals entering food consumed by humans or animal feed. In addition, the presence of these drugs in plants can affect plant metabolism, including the production of isoflavonoids.


Assuntos
Fenbendazol/metabolismo , Soja/metabolismo , Transporte Biológico , Biotransformação , Fenbendazol/farmacocinética
20.
Environ Res ; 200: 111368, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34081974

RESUMO

Organophosphorus insecticides (OPIs) have low persistence and are easily biodegradable in nature. The United States and India are the major countries producing OPIs of about 25% and 17% of the world, respectively. OPIs commonly used for agricultural practices occupy a major share in the global market, which leads to the increasing contamination of OPIs residues in various food chains. To overcome this issue, an enzymatic degradation method has been approved by several environmental toxic, and controlling agencies, including United States Environmental Protection Agency (USEPA). Different catalytic enzymes have been isolated and identified from various microbial sources to neutralize the toxic pesticides and/or insecticides. In this review, we have gathered information on OPIs biotransformation and their residual toxicity in the environment. Particularly, it focuses on OPIs degrading enzymes such as chlorpyrifos hydrolase, diisopropylfluorophosphatase, organophosphate acid anhydrolase, organophosphate hydrolases, and phosphotriesterases like lactonasesspecific activity either P-O link group type or P-S link group of pesticides. To summarize, the catalytic degradation of organophosphorus insecticides is not only profitable but also environmentally friendly. Hence, the enzymatic catalyst is an ultimate and super bio-weapon to mitigate or decontaminate various OPIs residues in both terrestrial and aqueous environments.


Assuntos
Clorpirifos , Inseticidas , Praguicidas , Biodegradação Ambiental , Biotransformação , Compostos Organofosforados/toxicidade
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