Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 18.208
Filtrar
1.
World J Microbiol Biotechnol ; 40(7): 200, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38730212

RESUMO

Recombinant protein production technology is widely applied to the manufacture of biologics used as drug substances and industrial proteins such as recombinant enzymes and bioactive proteins. Various heterologous protein production systems have been developed using prokaryotic and eukaryotic hosts. Especially methylotrophic yeast in eukaryotic hosts is suggested to be particularly valuable because such systems have the following advantages: protein secretion into culture broth, eukaryotic quality control systems, a post-translational modification system, rapid growth, and established recombinant DNA tools and technologies such as strong promoters, effective selection markers, and gene knock-in and -out systems. Many methylotrophic yeasts such as the genera Candida, Ogataea, and Komagataella have been studied since methylotrophic yeast was first isolated in 1969. The methanol-consumption-related genes in methylotrophic yeast are strongly and strictly regulated under methanol-containing conditions. The well-regulated gene expression systems under the methanol-inducible gene promoter lead to the potential application of heterologous protein production in methylotrophic yeast. In this review, we describe the recent progress of heterologous protein production technology in methylotrophic yeast and introduce Ogataea minuta as an alternative production host as a substitute for K. phaffii and O. polymorpha.


Assuntos
Metanol , Regiões Promotoras Genéticas , Proteínas Recombinantes , Saccharomycetales , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Metanol/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Regulação Fúngica da Expressão Gênica
2.
Vestn Oftalmol ; 140(2): 91-96, 2024.
Artigo em Russo | MEDLINE | ID: mdl-38742504

RESUMO

Optic nerve atrophy is a pathomorphological consequence of diseases of the peripheral neuron of the visual pathway, manifested as atrophy of nerve fibers of varying severity. The toxic effect of methanol is mainly associated with formic acid and formaldehyde, which suppress the cytochrome system, inhibit oxidative phosphorylation, and thereby cause a deficiency of adenosine triphosphoric acid, to which brain and retinal tissues are especially susceptible. When formiate accumulates, tissue respiration is disrupted, leading to pronounced tissue hypoxia. As a result of such methanol metabolism, metabolic acidosis occurs. Tissue hypoxia develops in the first few hours as a result of the action of formic acid on the respiratory enzyme chain at the cytochrome oxidase level. Hypoxia and, as a consequence, a decrease in energy supply lead to a disruption of biological oxidation and the development of apoptosis in the optic nerve fibers. Understanding the process of optic nerve atrophy development at the pathogenetic level in methyl alcohol intoxication will help make a correct early diagnosis and prescribe timely treatment.


Assuntos
Metanol , Nervo Óptico , Humanos , Metanol/intoxicação , Nervo Óptico/patologia , Nervo Óptico/efeitos dos fármacos , Atrofia Óptica/etiologia , Atrofia Óptica/diagnóstico , Atrofia Óptica/induzido quimicamente
3.
World J Microbiol Biotechnol ; 40(6): 188, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38702590

RESUMO

Methanol, the second most abundant volatile organic compound, primarily released from plants, is a major culprit disturbing atmospheric chemistry. Interestingly, ubiquitously found methanol-utilizing bacteria, play a vital role in mitigating atmospheric methanol effects. Despite being extensively characterized, the effect of nitrogen sources on the richness of methanol-utilizers in the bulk soil and rhizosphere is largely unknown. Therefore, the current study was planned to isolate, characterize and explore the richness of cultivable methylotrophs from the bulk soil and rhizosphere of a paddy field using media with varying nitrogen sources. Our data revealed that more genera of methylotrophs, including Methylobacterium, Ancylobacter, Achromobacter, Xanthobacter, Moraxella, and Klebsiella were enriched with the nitrate-based medium compared to only two genera, Hyphomicrobium and Methylobacterium, enriched with the ammonium-based medium. The richness of methylotrophic bacteria also differed substantially in the bulk soil as compared to the rhizosphere. Growth characterization revealed that majority of the newly isolated methanol-utilizing strains in this study exhibited better growth at 37 °C instead of 30 or 45 °C. Moreover, Hyphomicrobium sp. FSA2 was the only strain capable of utilizing methanol even at elevated temperature 45 °C, showing its adaptability to a wide range of temperatures. Differential carbon substrate utilization profiling revealed the facultative nature of all isolated methanol-utilizer strains with Xanthobacter sp. TS3, being an important methanol-utilizer capable of degrading toxic compounds such as acetone and ethylene glycol. Overall, our study suggests the role of nutrients and plant-microbial interaction in shaping the composition of methanol-utilizers in terrestrial environment.


Assuntos
Bactérias , Metanol , Nitrogênio , Oryza , Rizosfera , Microbiologia do Solo , Nitrogênio/metabolismo , Metanol/metabolismo , Oryza/microbiologia , Bactérias/classificação , Bactérias/metabolismo , Bactérias/isolamento & purificação , Solo/química , RNA Ribossômico 16S/genética , Filogenia , Minerais/metabolismo , Temperatura , Carbono/metabolismo
4.
Medicine (Baltimore) ; 103(18): e38039, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38701291

RESUMO

As a result of increasing drug resistance, crossover resistance development, prolonged therapy, and the absence of different agents with innovative methods for implementation, the efficacy of recent antileishmanial medications is severely declining. So, it is vital to look for other medications from botanical remedies that have antileishmanial activity. The latex of Euphorbia abyssinica (E abyssinica) and the leaves of Clematis simensis fresen (C simensis) were macerated in methanol (80%). In vitro antileishmanial activity of the preparation was tried on promastigotes of Leishmania aethiopica (L aethiopica) and Leishmania donovani (L donovani) using resazurin assay, and fluorescence intensity was measured. One percent of dimethyl sulfoxide (DMSO) and media as negative control and amphotericin B as positive control were used. Additionally, hemolytic & phytochemical tests of the preparation were done. The mean and standard errors of each extract were evaluated and interpreted for statistical significance using one-way analysis of variance. From sigmoidal dose-response curves of % inhibition, half maximal inhibitory concentration (IC50) values were determined by GraphPad Prism and Microsoft Excel; outcomes were presented as mean ±â€…standard error of mean of triplicate trials. P < .05 was statistical significance. The phytochemical screening of C simensis and E abyssinica confirmed the existence of steroids, phenols, tannins, saponins, alkaloids, terpenoids, flavonoids and glycosides. C simensis possesses antileishmanial activity with IC50 outcomes of 46.12 ±â€…0.03 and 8.18 ±â€…0.10 µg/mL on the promastigotes of L aethiopica and L donovani, respectively. However, E abyssinica showed stronger activity with IC50 outcomes of 16.07 ±â€…0.05 µg/mL and 4.82 ±â€…0.07 µg/mL on L aethiopica and L donovani, respectively. C simensis and E abyssinica have a less hemolytic effect on human red blood cells at low concentrations. The outcomes from this investigation demonstrated that the preparation of C simensis and E abyssinica indicated significant antileishmanial activity. Therefore, further in vivo assessment of antileishmanial, cytotoxicity activity and quantitative identification of secondary metabolites are highly recommended.


Assuntos
Antiprotozoários , Euphorbia , Látex , Extratos Vegetais , Folhas de Planta , Extratos Vegetais/farmacologia , Euphorbia/química , Látex/farmacologia , Látex/química , Antiprotozoários/farmacologia , Folhas de Planta/química , Humanos , Leishmania donovani/efeitos dos fármacos , Concentração Inibidora 50 , Leishmania/efeitos dos fármacos , Metanol , Solventes , Hemólise/efeitos dos fármacos
5.
J Chromatogr A ; 1725: 464930, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38696889

RESUMO

Unsuitable sample preparation may result in loss of important analytes and consequently affect the outcome of untargeted metabolomics. Due to species differences, different sample preparations may be required within the same biological matrix. The study aimed to compare the in-house sample preparation method for urine with methods from literature and to investigate the transferability of sample preparation from human urine to rat urine. A total of 12 different conditions for protein precipitation were tested, combining four different extraction solvents and three different reconstitution solvents using an untargeted liquid-chromatography high resolution mass spectrometry (LC-HRMS) metabolomics analysis. Evaluation was done based on the impact on feature count, their detectability, as well as the reproducibility of selected compounds. Results showed that a combination of methanol as extraction and acetonitrile/water (75/25) as reconstitution solvent provided improved results at least regarding the total feature count. Additionally, it was found that a higher amount of methanol was most suitable for extraction of rat urine among the tested conditions. In comparison, human urine requires significantly less volume of extraction solvent. Overall, it is recommended to systematically optimize both, the extraction method, and the reconstitution solvent for the used biofluid and the individual analytical settings.


Assuntos
Metabolômica , Metanol , Solventes , Animais , Ratos , Metabolômica/métodos , Humanos , Solventes/química , Metanol/química , Reprodutibilidade dos Testes , Cromatografia Líquida/métodos , Acetonitrilas/química , Masculino , Espectrometria de Massas/métodos , Urina/química , Água/química , Urinálise/métodos
6.
Anal Biochem ; 691: 115553, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38697592

RESUMO

We describe a microwave-assisted, methanol and acetic acid-free, inexpensive method for rapid staining of SDS-PAGE proteins. Only citric acid, benzoic acid, and Coomassie brilliant blue G-250 (CBG) were used. Microwave irradiation reduced the detection duration, and proteins in a clear background were visualized within 30 min of destaining, after 2 min of fixing and 12 min of staining. By using this protocol, comparable band intensities were obtained to the conventional methanol/acetic acid method.


Assuntos
Ácido Acético , Eletroforese em Gel de Poliacrilamida , Metanol , Micro-Ondas , Proteínas , Eletroforese em Gel de Poliacrilamida/métodos , Metanol/química , Proteínas/análise , Ácido Acético/química , Coloração e Rotulagem/métodos , Corantes de Rosanilina/química
7.
Molecules ; 29(9)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38731430

RESUMO

The root of Carlina acaulis L. has been widely used in traditional medicine for its antimicrobial properties. In this study, the fractionation of methanol extract from the root was conducted. Four fractions (A, B, C, and D) were obtained and tested against a range of bacteria and fungi. The results showed promising antibacterial activity, especially against Bacillus cereus, where the minimal inhibitory concentration (MIC) was determined to be equal to 0.08 mg/mL and 0.16 mg/mL for heptane (fraction B) and ethyl acetate (fraction C), respectively. In the case of the methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 strain, the same fractions yielded higher MIC values (2.5 and 5.0 mg/mL, respectively). This was accompanied by a lack of apparent cytotoxicity to normal human BJ foreskin fibroblasts, enterocytes derived from CaCo2 cells, and zebrafish embryos. Further analyses revealed the presence of bioactive chlorogenic acids in the fractionated extract, especially in the ethyl acetate fraction (C). These findings support the traditional use of the root from C. acaulis and pave the way for the development of new formulations for treating bacterial infections. This was further evaluated in a proof-of-concept experiment where fraction C was used in the ointment formulation, which maintained high antimicrobial activity against MRSA and displayed low toxicity towards cultured fibroblasts.


Assuntos
Antibacterianos , Bacillus cereus , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Extratos Vegetais , Raízes de Plantas , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Bacillus cereus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Raízes de Plantas/química , Animais , Células CACO-2 , Metanol/química , Fracionamento Químico , Peixe-Zebra
8.
Sci Total Environ ; 929: 172629, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38649057

RESUMO

In the context of the increasing global use of ethanol biofuel, this work investigates the concentrations of ethanol, methanol, and acetaldehyde, in both the gaseous phase and rainwater, across six diverse urban regions and biomes in Brazil, a country where ethanol accounts for nearly half the light-duty vehicular fuel consumption. Atmospheric ethanol median concentrations in São Paulo (SP) (12.3 ± 12.1 ppbv) and Ribeirão Preto (RP) (12.1 ± 10.9 ppbv) were remarkably close, despite the SP vehicular fleet being ∼13 times larger. Likewise, the rainwater VWM ethanol concentration in SP (4.64 ± 0.38 µmol L-1) was only 26 % higher than in RP (3.42 ± 0.13 µmol L-1). This work demonstrated the importance of evaporative emissions, together with biomass burning, as sources of the compounds studied. The importance of biogenic emissions of methanol during forest flooding was identified in campaigns in the Amazon and Atlantic forests. Marine air masses arriving at a coastal site led to the lowest concentrations of ethanol measured in this work. Besides vehicular and biomass burning emissions, secondary formation of acetaldehyde by photochemical reactions may be relevant in urban and non-urban regions. The combined deposition flux of ethanol and methanol was 6.2 kg ha-1 year-1, avoiding oxidation to the corresponding and more toxic aldehydes. Considering the species determined here, the ozone formation potential (OFP) in RP was around two-fold higher than in SP, further evidencing the importance of emissions from regional distilleries and biomass burning, in addition to vehicles. At the forest and coastal sites, the OFP was approximately 5 times lower than at the urban sites. Our work evidenced that transition from gasoline to ethanol or ethanol blends brings the associated risk of increasing the concentrations of highly toxic aldehydes and ozone, potentially impacting the atmosphere and threatening air quality and human health in urban areas.


Assuntos
Acetaldeído , Poluentes Atmosféricos , Monitoramento Ambiental , Etanol , Metanol , Chuva , Brasil , Acetaldeído/análise , Etanol/análise , Metanol/análise , Poluentes Atmosféricos/análise , Cidades
9.
Nanotheranostics ; 8(3): 312-329, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38577319

RESUMO

Cancer chemotherapy remains a serious challenge, and new approaches to therapy are urgently needed to build novel treatment regimens. The methanol extract of the stem of Tinospora Cordifolia was used to synthesize biogenic zinc oxide nanoparticles (ZnO-NPs) that display anticancer activities against colorectal cancer. Biogenic ZnO-NPs synthesized from methanol extract of Tinospora Cordifolia stem (ZnO-NPs TM) were tested against HCT-116 cell lines to assess anticancer activity. UV-Vis, FTIR, XRD, SEM, and TEM analysis characterized the biogenic ZnO-NPs. To see how well biogenic ZnO-NPs fight cancer, cytotoxicity, AO/EtBr staining, Annexin V/PI staining, mitochondrial membrane potential (MMP), generation of reactive oxygen species (ROS) analysis, and caspase cascade activity analysis were performed to assess the anticancer efficacy of biogenic ZnO-NPs. The IC50 values of biogenic ZnO-NPs treated cells (HCT-116 and Caco-2) were 31.419 ± 0.682µg/ml and 36.675 ± 0.916µg/ml, respectively. qRT-PCR analysis showed that cells treated with biogenic ZnO-NPs Bax and P53 mRNA levels increased significantly (p ≤ 0.001). It showed to have impaired MMP and increased ROS generation. In a corollary, our in vivo study showed that biogenic ZnO-NPs have an anti-tumour effect. Biogenic ZnO-NPs TM showed both in vitro and in vivo anticancer effects that could be employed as anticancer drugs.


Assuntos
Neoplasias Colorretais , Nanopartículas , Tinospora , Óxido de Zinco , Humanos , Óxido de Zinco/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Tinospora/metabolismo , Células CACO-2 , Metanol/farmacologia , Apoptose , Estresse Oxidativo , Neoplasias Colorretais/tratamento farmacológico
10.
Molecules ; 29(7)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38611754

RESUMO

In the current study, chromatographic and in silico techniques were applied to investigate the biotransformation of ethyl 5-(4-bromophenyl)-1-(2-(2-(2-hydroxybenzylidene) hydrazinyl)-2-oxoethyl)-2-methyl-1H-pyrrole-3-carboxylate (11b) in hepatocytic media. The initial chromatographic procedure was based on the employment of the conventional octadecyl stationary phase method for estimation of the chemical stability. Subsequently, a novel and rapid chromatographic approach based on a phenyl-hexyl column was developed, aiming to separate the possible metabolites. Both methods were performed on a Dionex 3000 ThermoScientific (ACM 2, Sofia, Bulgaria) device equipped with a diode array detector set up at 272 and 279 nm for analytes detection. An acetonitrile: phosphate buffer of pH 3.5: methanol (17:30:53 v/v/v) was eluted isocratically as a mobile phase with a 1 mL/min flow rate. A preliminary purification from the biological media was achieved by protein precipitation with methanol. A validation procedure was carried out, where the method was found to correspond to all ICH (Q2) and M10 set criteria. Additionally, an in silico-based approach with the online server BioTransformer 3.0 was applied in an attempt to predict the possible metabolites of the title compound 11b. It was hypothesized that four CYP450 isoforms (1A2, 2C9, 3A4, and 2C8) were involved in the phase I metabolism, resulting in the formation of 12 metabolites. Moreover, docking studies were conducted to evaluate the formation of stable complexes between 11b and the aforementioned isoforms. The obtained data indicated three metabolites as the most probable products, two of which (M9_11b and M10_11b) were synthesized by a classical approach for verification. Finally, liquid chromatography with a mass detector was implemented for comprehensive and summarized analysis, and the obtained results revealed that the metabolism of the 11b proceeds possibly with the formation of glucuronide and glycine conjugate of M11_11b.


Assuntos
Hepatócitos , Metanol , Animais , Ratos , Estudos Prospectivos , Biotransformação , Cromatografia Líquida , Hidrazonas , Isoformas de Proteínas
11.
Molecules ; 29(7)2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38611770

RESUMO

Irritable bowel syndrome (IBS), a common gastrointestinal disorder worldwide, is characterized by chronic abdominal pain, bloating, and disordered defecation. IBS is associated with several factors, including visceral hypersensitivity, gut motility, and gut-brain interaction disorders. Because currently available pharmacological treatments cannot adequately improve symptoms and may cause adverse effects, the use of herbal therapies for managing IBS is increasing. Lysimachia vulgaris var. davurica (LV) is a medicinal plant used in traditional medicine to treat diarrhea. However, information on whether LV can effectively improve diarrhea-predominant IBS (IBS-D) remains limited. In this study, using an experimental mouse model of IBS-D, we elucidated the effects of the LV extract. The methanol extract of LV decreased fecal pellet output in the restraint stress- or 5-hydroxytryptamine (5-HT)-induced IBS mouse model and inhibited 5-HT-mediated [Ca2+]i increase in a dose-dependent manner. Furthermore, we developed and validated a high-performance liquid chromatography method using two marker compounds, namely, chlorogenic acid and rutin, for quality control analysis. Our study results suggest the feasibility of the methanol extract of LV for developing therapeutic agents to treat IBS-D by acting as a 5-HT3 receptor antagonist.


Assuntos
Encefalopatias , Síndrome do Intestino Irritável , Animais , Camundongos , Síndrome do Intestino Irritável/tratamento farmacológico , Cromatografia Líquida de Alta Pressão , Lysimachia , Metanol , Serotonina , Diarreia/tratamento farmacológico , Modelos Animais de Doenças , Extratos Vegetais/farmacologia
12.
J Chromatogr A ; 1722: 464856, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38579610

RESUMO

Complex mixture analysis requires high-efficiency chromatography columns. Although reversed phase liquid chromatography (RPLC) is the dominant approach for such mixtures, hydrophilic interaction liquid chromatography (HILIC) is an important complement to RPLC by enabling the separation of polar compounds. Chromatography theory predicts that small particles and long columns will yield high efficiency; however, little work has been done to prepare HILIC columns longer than 25 cm packed with sub-2 µm particles. In this work, we tested the slurry packing of 75 cm long HILIC columns with 1.7 µm bridged-ethyl-hybrid amide HILIC particles at 2,100 bar (30,000 PSI). Acetonitrile, methanol, acetone, and water were tested as slurry solvents, with acetonitrile providing the best columns. Slurry concentrations of 50-200 mg/mL were assessed, and while 50-150 mg/mL provided comparable results, the 150 mg/mL columns provided the shortest packing times (9 min). Columns prepared using 150 mg/mL slurries in acetonitrile yielded a reduced minimum plate height (hmin) of 3.3 and an efficiency of 120,000 theoretical plates for acenaphthene, an unretained solute. Para-toluenesulfonic acid produced the lowest hmin of 1.9 and the highest efficiency of 210,000 theoretical plates. These results identify conditions for producing high-efficiency HILIC columns with potential applications to complex mixture analysis.


Assuntos
Acetonitrilas , Benzenossulfonatos , Interações Hidrofóbicas e Hidrofílicas , Acetonitrilas/química , Cromatografia Líquida/métodos , Cromatografia de Fase Reversa/métodos , Cromatografia de Fase Reversa/instrumentação , Metanol/química , Solventes/química , Acetona/química , Tamanho da Partícula , Pressão , Água/química
13.
BMC Emerg Med ; 24(1): 64, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627622

RESUMO

BACKGROUND: Acute methanol intoxication, whether unintentional or deliberate, necessitates prompt intervention to prevent severe morbidity and mortality. Homemade alcoholic beverages are a frequent source of such poisoning. This retrospective analysis examined two outbreaks of methanol intoxication in Saudi Arabia. It investigated the clinical presentation, implemented management strategies, and any lasting complications (sequelae) associated with these cases. The aim was to assess the potential impact of different treatment modalities and the timeliness of their initiation on patient outcomes. METHODS: This was a retrospective case series of methanol poisoning cases which presented to the adult emergency department (ED) at King Abdulaziz Medical City (KAMC) in Riyadh, Saudi Arabia. There were two separate outbreaks in the city, the first one was from September 1 to September 10, 2020 and the second one was from May 14 to May 20, 2021. Electronic charts were reviewed, and data were extracted to previously prepared data extraction sheets. RESULT: From the 22 patients who arrived in the ED alive, the most common complaints were nausea or vomiting followed by altered level of consciousness. About 9% from the patient were hypotensive, 36% were tachycardic, 41% were tachypneic and 4% were having SpO2 < 94%. Brain CT was abnormal in 6 patients. Vision impairment was the most common sequalae of methanol poisoning (7 out of 12 patients who were assessed by ophthalmologist, 58%). When the patients were divided based on severity (mild, moderate, severe), nausea or vomiting and loss of consciousness were the most common complaints among the moderate group while loss of consciousness predominated in the severe group. Two patients presented with low blood pressure and were in the sever group. The severe group had a mean Glasgow Coma Scale (GCS) of 8. Most of the patients in the severity groups underwent the same management apart from those who died or deposited. Eight patients in the severe group had to be intubated. CONCLUSION: This study demonstrates the multifaceted clinical presentation of methanol poisoning, culminating in a 17.4% mortality rate. Notably, our findings emphasize the critical role of prompt diagnosis and swift initiation of combined fomepizole therapy and hemodialysis in mitigating mortality and minimizing the potential for chronic visual sequelae associated with methanol poisoning.


Assuntos
Metanol , Intoxicação , Adulto , Humanos , Metanol/uso terapêutico , Estudos Retrospectivos , Arábia Saudita/epidemiologia , Surtos de Doenças , Náusea/epidemiologia , Vômito/epidemiologia , Inconsciência , Intoxicação/epidemiologia , Intoxicação/terapia
15.
Int J Mol Sci ; 25(7)2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38612389

RESUMO

Alkaline earth metal oxide (MgO, CaO, SrO) catalysts supported on BEA zeolite were prepared by a wet impregnation method and tested in the transesterification reaction of rapeseed oil with methanol towards the formation of biodiesel (FAMEs-fatty acid methyl esters). To assess the influence of the SiO2/Al2O3 ratio on the catalytic activity in the tested reaction, a BEA zeolite carrier material with different Si/Al ratios was used. The prepared catalysts were tested in the transesterification reaction at temperatures of 180 °C and 220 °C using a molar ratio of methanol/oil reagents of 9:1. The transesterification process was carried out for 2 h with the catalyst mass of 0.5 g. The oil conversion value and efficiency towards FAME formation were determined using the HPLC technique. The physicochemical properties of the catalysts were determined using the following research techniques: CO2-TPD, XRD, BET, FTIR, and SEM-EDS. The results of the catalytic activity showed that higher activity in the tested process was confirmed for the catalysts supported on the BEA zeolite characterized by the highest silica/alumina ratio for the reaction carried out at a temperature of 220 °C. The most active zeolite catalyst was the 10% CaO/BEA system (Si/Al = 300), which showed the highest triglyceride (TG) conversion of 90.5% and the second highest FAME yield of 94.6% in the transesterification reaction carried out at 220 °C. The high activity of this system is associated with its alkalinity, high value of the specific surface area, the size of the active phase crystallites, and its characteristic sorption properties in relation to methanol.


Assuntos
Biocombustíveis , Zeolitas , Óxido de Magnésio , Metanol , Óleo de Brassica napus , Dióxido de Silício , Ácidos Graxos , Óxidos
16.
Mymensingh Med J ; 33(2): 350-355, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38557509

RESUMO

Evaluation of the in vitro antibacterial activity of Methanolic extracts isolated from Black pepper seeds (Piper nigrum L.) against two infection causing pathogens, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Between July 2022 and June 2023, this experimental study was conducted at the Mymensingh Medical College's Department of Pharmacology and Therapeutics in conjunction with the Department of Microbiology. Using the disc diffusion and broth dilution methods, the antibacterial activity of methanolic extract of black pepper seeds (MBPE) was evaluated at various doses. The solvents Methanol and 10.0% Di Methyl Sulfoxide (DMSO) were used to make the extract. Using the broth dilution procedure, the conventional antibiotic Ciprofloxacin was utilized and the outcome was contrasted with that of Methanol extracts. Methanolic extract of black pepper seeds (MBPE) at seven distinct concentrations (100, 80, 60, 40, 20, 10 and 5 mg/ml) were utilized, then later in chosen concentrations as needed to confirm the extracts' more precise margin of antimicrobial sensitivity. At 80 mg/ml and above doses of the MBPE, it had an inhibitory impact against the aforementioned microorganisms. For Staphylococcus aureus and Escherichia coli the MIC were 60 and 75 mg/ml in MBPE respectively. As of the MIC of Ciprofloxacin was 1µg/ml against Staphylococcus aureus and Escherichia coli. In comparison to MICs of MBPE for the test organisms, the MIC of Ciprofloxacin was the lowest. This study clearly shows that Staphylococcus aureus and Escherichia coli are sensitive to the methanolic extract of black pepper seeds' antibacterial properties.


Assuntos
Piper nigrum , Staphylococcus aureus , Humanos , Metanol , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Ciprofloxacina , Sementes , Escherichia coli
17.
Microb Cell Fact ; 23(1): 99, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566096

RESUMO

BACKGROUND: The yeast Komagataella phaffii has become a very popular host for heterologous protein expression, very often based on the use of the AOX1 promoter, which becomes activated when cells are grown with methanol as a carbon source. However, the use of methanol in industrial settings is not devoid of problems, and therefore, the search for alternative expression methods has become a priority in the last few years. RESULTS: We recently reported that moderate alkalinization of the medium triggers a fast and wide transcriptional response in K. phaffii. Here, we present the utilization of three alkaline pH-responsive promoters (pTSA1, pHSP12 and pPHO89) to drive the expression of a secreted phytase enzyme by simply shifting the pH of the medium to 8.0. These promoters offer a wide range of strengths, and the production of phytase could be modulated by adjusting the pH to specific values. The TSA1 and PHO89 promoters offered exquisite regulation, with virtually no enzyme production at acidic pH, while limitation of Pi in the medium further potentiated alkaline pH-driven phytase expression from the PHO89 promoter. An evolved strain based on this promoter was able to produce twice as much phytase as the reference pAOX1-based strain. Functional mapping of the TSA1 and HSP12 promoters suggests that both contain at least two alkaline pH-sensitive regulatory regions. CONCLUSIONS: Our work shows that the use of alkaline pH-regulatable promoters could be a useful alternative to methanol-based expression systems, offering advantages in terms of simplicity, safety and economy.


Assuntos
6-Fitase , Saccharomycetales , Pichia/metabolismo , Metanol/metabolismo , 6-Fitase/genética , 6-Fitase/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Concentração de Íons de Hidrogênio , Proteínas Recombinantes/metabolismo
18.
Water Environ Res ; 96(4): e11017, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38565318

RESUMO

This study explored the implementation of mainstream partial denitrification with anammox (PdNA) in the second anoxic zone of a wastewater treatment process in an integrated fixed film activated sludge (IFAS) configuration. A pilot study was conducted to compare the use of methanol and glycerol as external carbon sources for an IFAS PdNA startup, with a goal to optimize nitrogen removal while minimizing carbon usage. The study also investigated the establishment of anammox bacteria on virgin carriers in IFAS reactors without the use of seeding, and it is the first IFAS PdNA startup to use methanol as an external carbon source. The establishment of anammox bacteria was confirmed in both reactors 102 days after startup. Although the glycerol-fed reactor achieved a higher steady-state maximum ammonia removal rate because of anammox bacteria (1.6 ± 0.3 g/m2/day) in comparison with the methanol-fed reactor (1.2 ± 0.2 g/m2/day), both the glycerol- and methanol-fed reactors achieved similar average in situ ammonia removal rates of 0.39 ± 0.2 g/m2/day and 0.40 ± 0.2 g/m2/day, respectively. Additionally, when the upstream ammonia versus NOx (AvN) control system maintained an ideal ratio of 0.40-0.50 g/g, the methanol-fed reactor attained a lower average effluent TIN concentration (3.50 ± 1.2 mg/L) than the glycerol-fed reactor (4.43 ± 1.6 mg/L), which was prone to elevated nitrite concentrations in the effluent. Overall, this research highlights the potential for PdNA in IFAS configurations as an efficient and cost-saving method for wastewater treatment, with methanol as a viable carbon source for the establishment of anammox bacteria. PRACTITIONER POINTS: Methanol is an effective external carbon source for an anammox startup that avoids the need for costly alternative carbon sources. The methanol-fed reactor demonstrated higher TIN removal compared with the glycerol-fed reactor because of less overproduction of nitrite. Anammox bacteria was established in an IFAS reactor without seeding and used internally stored carbon to reduce external carbon addition. Controlling the influent ammonia versus NOx (AvN) ratio between 0.40 and 0.50 g/g allowed for low and stable TIN effluent conditions.


Assuntos
Compostos de Amônio , Esgotos , Esgotos/microbiologia , Amônia , Desnitrificação , Metanol , Glicerol , Nitritos , Projetos Piloto , Oxidação Anaeróbia da Amônia , Reatores Biológicos/microbiologia , Bactérias , Nitrogênio , Oxirredução
19.
BMC Complement Med Ther ; 24(1): 137, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566161

RESUMO

BACKGROUND: A study carried out by World Health Organization revealed that around 80% of individuals globally depends on herbal forms of medication with 40% of pharmaceutical products being sourced from medicinal plants. The study objective was to evaluate the phytochemicals composition, in vitro antimicrobial and antioxidant properties of the leaves of Terminalia catappa L. aqueous and methanolic extracts. METHODS: Antimicrobial activity was analyzed by disk diffusion, the minimum inhibitory concentration in-vitro assays with ciprofloxacin as the standard for antibacterial assay while nystatin for antifungal assay. Ferric reducing antioxidant power and 2,2-diphenyl-1-picryl-hydrazyl-hydrate assays were used for the evaluation of antioxidant properties of the crude extracts while the groups responsible for this activity identified using Fourier transform infrared spectrophotometer. RESULTS: The study found that the leaves of Terminalia catappa contained alkaloids, tannins, steroids, cardiac glycosides, flavonoids, phenols, saponins, and coumarins, but terpenoids were absent. Presence of functional groups associated with this class of compounds such as OH vibrational frequencies were observed in IR spectrum of the crude extracts. Methanolic extract from Terminalia catappa exhibited greater antibacterial properties against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus, whereas aqueous extract displayed greater antibacterial activity against Bacillus subtilis for all concentrations tested. The amount of the sample that scavenged 50 percent of DPPH (IC50) was found to be 8.723, 13.42 and 13.04 µg/mL for L-ascorbic acid, Terminalia catappa L. methanolic and aqueous extracts respectively. The antimicrobial and antioxidant activities varied with the extract concentration and solvent used in extractions. CONCLUSION: Terminalia catappa L. leaves are prospective for use as a source of therapeutic agents that could lead to the advancement of new antimicrobial and antioxidant products.


Assuntos
Anti-Infecciosos , Terminalia , Humanos , Antioxidantes/química , Metanol , Terminalia/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Estudos Prospectivos , Anti-Infecciosos/química , Antibacterianos/farmacologia , Antibacterianos/química , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/química , Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA