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Applied and Environmental Microbiology Mar 2022Using the Wood-Ljungdahl pathway, acetogens can nonphotosynthetically fix gaseous C molecules, preventing them from entering the atmosphere. Many acetogens can also grow...
Using the Wood-Ljungdahl pathway, acetogens can nonphotosynthetically fix gaseous C molecules, preventing them from entering the atmosphere. Many acetogens can also grow on liquid C compounds such as formate and methanol, which avoid the storage and mass transfer issues associated with gaseous C compounds. Substrate redox state also plays an important role in acetogen metabolism and can modulate products formed by these organisms. is an acetogen known for its ability to synthesize longer-chained molecules such as butyrate and butanol, which have significantly higher values than acetate or ethanol, from one-carbon (C) compounds. We explored C metabolism by varying substrates, substrate concentrations, and substrate feeding strategies to improve four-carbon product titers. Our results showed that formate utilization by favored acetate production and methanol utilization favored butyrate production. Cofeeding of both substrates produced a high butyrate titer of 4 g/liter when methanol was supplied in excess to formate. Testing of formate feeding strategies, in the presence of methanol, led to further increases in the butyrate to acetate ratio. Mixotrophic growth of liquid and gaseous C substrates expanded the product profile, as ethanol, butanol, and lactate were produced under these conditions. We also showed that is capable of producing caproate, a six-carbon product, presumably through chain elongation cycles of the reverse β-oxidation pathway. Furthermore, we demonstrated butanol production via heterologous gene expression. Our results indicate that both selection of appropriate substrates and genetic engineering play important roles in determining titers of desired products. Acetogenic bacteria can fix single-carbon (C) molecules. However, improvements are needed to overcome poor product titers. can naturally ferment C compounds into longer-chained molecules such as butyrate alongside traditional acetate. Here, we show that can effectively grow on formate and methanol to produce high titers of butyrate. We improved ratios of butyrate to acetate through adjusted formate feeding strategies and produced higher-value six-carbon molecules. We also expanded the product profile with the addition of C gases, as the organism produced ethanol, butanol, and lactate. Furthermore, we developed a transformation protocol for to facilitate genetic engineering of this organism for the circular bioeconomy.
Topics: Acetates; Carbon Monoxide; Clostridium; Methanol
PubMed: 35138930
DOI: 10.1128/aem.02393-21 -
Biotechnology Advances 2020Methanol is a very promising feedstock alternative to sugar-based raw materials for biomanufacturing because it does not compete with food production, is abundant and... (Review)
Review
Methanol is a very promising feedstock alternative to sugar-based raw materials for biomanufacturing because it does not compete with food production, is abundant and potentially sustainable in the future. Although methylotrophic fermentations have been practiced for decades, their applications are limited by technical drawbacks and insufficient knowledge of the physiology and metabolic regulation of native methylotrophs. Synthetic biology offers great opportunities for engineering efficient methylotrophic microbial cell factories by enabling non-methylotrophic model organisms to utilize methanol via the introduction of C1 utilization pathways. This review critically comments C1 metabolism with a focus on comparing different methanol-utilization pathways in light of biomanufacturing, and highlights recent advances in the engineering of synthetic methylotrophs. Most importantly, the unique challenges in the engineering process and possible solutions are also discussed in detail.
Topics: Fermentation; Metabolic Engineering; Methanol; Synthetic Biology
PubMed: 31697995
DOI: 10.1016/j.biotechadv.2019.107467 -
Natural Product Research Feb 2022(water mimosa) is an edible medicinal plant used in treating various diseases. According to Phytochemical and Ethnobotanical Databases, is used in curing earaches,...
(water mimosa) is an edible medicinal plant used in treating various diseases. According to Phytochemical and Ethnobotanical Databases, is used in curing earaches, dysentery, syphilis, and tumour. The present study was aimed at demonstrating the anticancer activity of the methanolic extract. The methanolic extract was isolated and its anti-proliferative activity was studied on haematological cancer cell lines. The activity of the extract was further evaluated using cell cycle analysis and apoptosis assays. In addition to this, effect of the extract on c-Myc and PErk1/2 modulation was also evaluated. extract induced cell death in cancer cells while sparing normal cells. An increase in cleaved PARP and reduction in BCL-2 levels observed upon treatment causes reduction in c-Myc levels and pERK1/2 protein levels. Thus, our work highlights the methanolic extract of as a promising anti-cancer agent.
Topics: Apoptosis; Fabaceae; Methanol; Plant Extracts
PubMed: 33213226
DOI: 10.1080/14786419.2020.1844693 -
International Journal of Molecular... Apr 2022One- or two-carbon (C1 or C2) compounds have been considered attractive substrates because they are inexpensive and abundant. Methanol and ethanol are representative C1...
One- or two-carbon (C1 or C2) compounds have been considered attractive substrates because they are inexpensive and abundant. Methanol and ethanol are representative C1 and C2 compounds, which can be used as bio-renewable platform feedstocks for the biotechnological production of value-added natural chemicals. Methanol-derived formaldehyde and ethanol-derived acetaldehyde can be converted to 3-hydroxypropanal (3-HPA) via aldol condensation. 3-HPA is used in food preservation and as a precursor for 3-hydroxypropionic acid and 1,3-propanediol that are starting materials for manufacturing biocompatible plastic and polytrimethylene terephthalate. In this study, 3-HPA was biosynthesized from formaldehyde and acetaldehyde using deoxyribose-5-phosphate aldolase from (DERA) and cloned and expressed in for 3-HPA production. Under optimum conditions, DERA produced 7 mM 3-HPA from 25 mM substrate (formaldehyde and acetaldehyde) for 60 min with 520 mg/L/h productivity. To demonstrate the one-pot 3-HPA production from methanol and ethanol, we used methanol dehydrogenase from (MDH) and DERA. One-pot 3-HPA production via aldol condensation of formaldehyde and acetaldehyde from methanol and ethanol, respectively, was investigated under optimized reaction conditions. This is the first report on 3-HPA production from inexpensive alcohol substrates (methanol and ethanol) by cascade reaction using DERA and MDH.
Topics: Acetaldehyde; Escherichia coli; Ethanol; Formaldehyde; Methanol
PubMed: 35409349
DOI: 10.3390/ijms23073990 -
Applied and Environmental Microbiology Sep 2020Industrial methanol production converts methane from natural gas into methanol through a multistep chemical process. Biological methane-to-methanol conversion under...
Industrial methanol production converts methane from natural gas into methanol through a multistep chemical process. Biological methane-to-methanol conversion under moderate conditions and using biogas would be more environmentally friendly. Methanotrophs, bacteria that use methane as an energy source, convert methane into methanol in a single step catalyzed by the enzyme methane monooxygenase, but inhibition of methanol dehydrogenase, which catalyzes the subsequent conversion of methanol into formaldehyde, is a major challenge. In this study, we used the thermoacidophilic methanotroph "" SolV for biological methanol production. This bacterium possesses a XoxF-type methanol dehydrogenase that is dependent on rare earth elements for activity. By using a cultivation medium nearly devoid of lanthanides, we reduced methanol dehydrogenase activity and obtained a continuous methanol-producing microbial culture. The methanol production rate and conversion efficiency were growth-rate dependent. A maximal conversion efficiency of 63% mol methanol produced per mol methane consumed was obtained at a relatively high growth rate, with a methanol production rate of 0.88 mmol/g (dry weight)/h. This study demonstrates that methanotrophs can be used for continuous methanol production. Full-scale application will require additional increases in the titer, production rate, and efficiency, which can be achieved by further decreasing the lanthanide concentration through the use of increased biomass concentrations and novel reactor designs to supply sufficient gases, including methane, oxygen, and hydrogen. The production of methanol, an important chemical, is completely dependent on natural gas. The current multistep chemical process uses high temperature and pressure to convert methane in natural gas to methanol. In this study, we used the methanotroph "" SolV to achieve continuous methanol production from methane as the substrate. The production rate was highly dependent on the growth rate of this microorganism, and high conversion efficiencies were obtained. Using microorganisms for the production of methanol might enable the use of more sustainable sources of methane, such as biogas, rather than natural gas.
Topics: Methane; Methanol; Verrucomicrobia
PubMed: 32631865
DOI: 10.1128/AEM.01188-20 -
ACS Sensors Aug 2022Methanol is a major volatile organic compound (VOC) emitted from plants. Methanol emission reflects indirect plant defense against insects, promotes cell-to-cell...
Methanol is a major volatile organic compound (VOC) emitted from plants. Methanol emission reflects indirect plant defense against insects, promotes cell-to-cell communication, and adapts plants to various environmental stresses. This paper reports a wearable plant sensor that can monitor methanol emission directly on the leaf of a plant under field conditions with low cost, high portability, and easy installation and use. The sensor technology eliminates the need for complex sampling, expensive instruments, and skilled operators for conventional gas chromatography-mass spectrometry. The sensor uses a composite of conducting polymer microcrystallites and platinum nanoparticles (PtNPs). The conducting poly(2-amino-1,3,4-thiadiazole) or poly(ATD) provides a high electrocatalytic activity with redox behavior. The modification of poly(ATD) with catalytic PtNPs enables efficient electrochemical oxidation of methanol at a specific potential. The advantages of poly(ATD) and PtNPs are synergized for high sensitivity and selectivity of the sensor for detecting methanol emissions with a sub-ppm limit of detection. Further, the infusion of a polymer electrolyte into the porous electrode of the sensor enables an all-solid-state VOC sensor. The sensor is integrated into a miniature gas collection chamber and capped with a hydrophobic gas diffusion membrane to minimize the influence of environmental humidity on the sensor performance. The sensor is installed on the leaf surface. In situ detection shows a difference in methanol emission between the lower and upper leaves of greenhouse maize plants. Further, under field conditions, the sensor reveals a noticeable difference in methanol emission concentration between two genotypes (Mo17 and B73 inbred lines) of maize plants. Therefore, the sensor will provide a promising new means of directly monitoring volatile emission of plants, which is a physiological phenotype as a function of genes and environment.
Topics: Metal Nanoparticles; Methanol; Plants; Platinum; Polymers; Volatile Organic Compounds; Wearable Electronic Devices
PubMed: 35939805
DOI: 10.1021/acssensors.2c00834 -
Methods in Molecular Biology (Clifton,... 2021Alcohol oxidase (EC 1.1.3.13; AOX) is a flavoprotein that catalyzes the oxidation of primary short-chain alcohols to corresponding carbonyl compounds with a concomitant... (Review)
Review
Alcohol oxidase (EC 1.1.3.13; AOX) is a flavoprotein that catalyzes the oxidation of primary short-chain alcohols to corresponding carbonyl compounds with a concomitant release of hydrogen peroxide. It is a key enzyme of methanol metabolism in methylotrophic yeasts, catalyzing the first step of methanol oxidation to formaldehyde.Here we describe the isolation and purification of AOX from the thermotolerant methylotrophic yeast Ogataea (Hansenula) polymorpha, and using this enzyme in enzymatic assay of ethanol, simultaneous analysis of methanol and formaldehyde, and in construction of amperometric biosensors selective to primary alcohols and formaldehyde.
Topics: Alcohol Oxidoreductases; Batch Cell Culture Techniques; Biosensing Techniques; Chromatography, Ion Exchange; Cloning, Molecular; Formaldehyde; Fungal Proteins; Methanol; Saccharomycetales
PubMed: 33751439
DOI: 10.1007/978-1-0716-1286-6_15 -
Natural Product Research Jun 2022This work presents the volatile compounds and phenolic profile investigation of the leaves of L. growing in Tunisia, together with antioxidant and antibacterial...
This work presents the volatile compounds and phenolic profile investigation of the leaves of L. growing in Tunisia, together with antioxidant and antibacterial properties. Volatile constituents were determined by HS-SPME coupled to GC/MS, and the results showed that α-pinene (31.6%) and limonene (16.9%) were the main volatiles. The phenolic profile was determined by HPLC analysis, the methanol extract revealed the presence of four hydroxycinnamic acids (chlorogenic, ferulic, p-coumaric and sinapic acids), two hydroxybenzoic acids (syringic and gallic acids), and four flavonoids (catechol, catechin hydrate, epigallocatechin and epicatechin 3-O-gallate). The methanol extract showed the best significantly antiradical activity by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS ((2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) antioxidant assays, with EC of 0.32 and 0.45 mg/mL, respectively. For antibacterial activity, the methanol extract inhibits all the tested strains. It can be concluded that kohlrabi leaves are rich in bioactive compounds and are a potential source of natural antioxidants and antibacterials.
Topics: Anti-Bacterial Agents; Antioxidants; Methanol; Phenols; Plant Extracts; Plant Leaves
PubMed: 34154474
DOI: 10.1080/14786419.2021.1940177 -
Sensors (Basel, Switzerland) Jul 2022Methanol, naturally present in small quantities in the distillation of alcoholic beverages, can lead to serious health problems. When it exceeds a certain concentration,...
Methanol, naturally present in small quantities in the distillation of alcoholic beverages, can lead to serious health problems. When it exceeds a certain concentration, it causes blindness, organ failure, and even death if not recognized in time. Analytical techniques such as chromatography are used to detect dangerous concentrations of methanol, which are very accurate but also expensive, cumbersome, and time-consuming. Therefore, a gas sensor that is inexpensive and portable and capable of distinguishing methanol from ethanol would be very useful. Here, we present a resistive gas sensor, based on tin oxide nanowires, that works in a thermal gradient. By combining responses at various temperatures and using machine learning algorithms (PCA, SVM, LDA), the device can distinguish methanol from ethanol in a wide range of concentrations (1-100 ppm) in both dry air and under different humidity conditions (25-75% RH). The proposed sensor, which is small and inexpensive, demonstrates the ability to distinguish methanol from ethanol at different concentrations and could be developed both to detect the adulteration of alcoholic beverages and to quickly recognize methanol poisoning.
Topics: Alcoholic Beverages; Ethanol; Machine Learning; Methanol; Nanowires
PubMed: 35898057
DOI: 10.3390/s22155554 -
Molecules (Basel, Switzerland) Apr 2021Methanol is a natural ingredient with major occurrence in fruit spirits, such as apple, pear, plum or cherry spirits, but also in spirits made from coffee pulp. The... (Review)
Review
Methanol is a natural ingredient with major occurrence in fruit spirits, such as apple, pear, plum or cherry spirits, but also in spirits made from coffee pulp. The compound is formed during fermentation and the following mash storage by enzymatic hydrolysis of naturally present pectins. Methanol is toxic above certain threshold levels and legal limits have been set in most jurisdictions. Therefore, the methanol content needs to be mitigated and its level must be controlled. This article will review the several factors that influence the methanol content including the pH value of the mash, the addition of various yeast and enzyme preparations, fermentation temperature, mash storage, and most importantly the raw material quality and hygiene. From all these mitigation possibilities, lowering the pH value and the use of cultured yeasts when mashing fruit substances is already common as best practice today. Also a controlled yeast fermentation at acidic pH facilitates not only reduced methanol formation, but ultimately also leads to quality benefits of the distillate. Special care has to be observed in the case of spirits made from coffee by-products which are prone to spoilage with very high methanol contents reported in past studies.
Topics: Alcoholic Beverages; Fermentation; Food Quality; Fruit; Hydrogen-Ion Concentration; Kinetics; Methanol
PubMed: 33925245
DOI: 10.3390/molecules26092585