scholarly journals Methanol Dehydrogenases as a Key Biocatalysts for Synthetic Methylotrophy

Author(s):  
Thien-Kim Le ◽  
Yu-Jin Lee ◽  
Gui Hwan Han ◽  
Soo-Jin Yeom

One-carbon (C1) chemicals are potential building blocks for cheap and sustainable re-sources such as methane, methanol, formaldehyde, formate, carbon monoxide, and more. These resources have the potential to be made into raw materials for various products used in our daily life or precursors for pharmaceuticals through biological and chemical processes. Among the soluble C1 substrates, methanol is regarded as a biorenewable platform feedstock because nearly all bioresources can be converted into methanol through syngas. Synthetic methylotrophy can be exploited to produce fuels and chemicals using methanol as a feedstock that integrates natural or artificial methanol assimilation pathways in platform microorganisms. In the methanol utilization in methylotrophy, methanol dehydrogenase (Mdh) is a primary enzyme that converts methanol to formaldehyde. The discovery of new Mdhs and engineering of present Mdhs have been attempted to develop synthetic methylotrophic bacteria. In this review, we describe Mdhs, including in terms of their enzyme properties and engineering for desired activity. In addition, we specifically focus on the application of various Mdhs for synthetic methylotrophy.

2016 ◽  
Vol 37 (3) ◽  
pp. 181-193 ◽  
Author(s):  
Aire Mill ◽  
Anu Realo ◽  
Jüri Allik

Abstract. Intraindividual variability, along with the more frequently studied between-person variability, has been argued to be one of the basic building blocks of emotional experience. The aim of the current study is to examine whether intraindividual variability in affect predicts tiredness in daily life. Intraindividual variability in affect was studied with the experience sampling method in a group of 110 participants (aged between 19 and 84 years) during 14 consecutive days on seven randomly determined occasions per day. The results suggest that affect variability is a stable construct over time and situations. Our findings also demonstrate that intraindividual variability in affect has a unique role in predicting increased levels of tiredness at the momentary level as well at the level of individuals.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 381
Author(s):  
Alessandro Nanni ◽  
Mariafederica Parisi ◽  
Martino Colonna

The plastic industry is today facing a green revolution; however, biopolymers, produced in low amounts, expensive, and food competitive do not represent an efficient solution. The use of wine waste as second-generation feedstock for the synthesis of polymer building blocks or as reinforcing fillers could represent a solution to reduce biopolymer costs and to boost the biopolymer presence in the market. The present critical review reports the state of the art of the scientific studies concerning the use of wine by-products as substrate for the synthesis of polymer building blocks and as reinforcing fillers for polymers. The review has been mainly focused on the most used bio-based and biodegradable polymers present in the market (i.e., poly(lactic acid), poly(butylene succinate), and poly(hydroxyalkanoates)). The results present in the literature have been reviewed and elaborated in order to suggest new possibilities of development based on the chemical and physical characteristics of wine by-products.


1992 ◽  
Vol 267 (31) ◽  
pp. 22289-22297
Author(s):  
Z.X. Xia ◽  
W.W. Dai ◽  
J.P. Xiong ◽  
Z.P. Hao ◽  
V.L. Davidson ◽  
...  

2021 ◽  
Vol 877 ◽  
pp. 141-146
Author(s):  
David Lie ◽  
Tjokorda Gde Tirta Nindhia ◽  
I Wayan Surata ◽  
Nengah Wirawan

The available of conventional fuels are fluctuating depend on distribution from the source production to consumer. The availability of biogas as renewable energy is increasing due to establishments of many organic wastes processing worldwide. The need of electricity to support daily life activity is a must, but the availability of electric source in remote area is limited especially for a farm that far away from commercial line distribution of electricity. This work is dedicated to solve this problem. The single cylinder 4 stroke spark ignition engine (83 cc) was designed to be able to be fuelled flexibly by using biogas or liquefied petroleum gas (LPG), or gasoline if sometime the biogas not available during initiation of the process or during maintenance of anaerobic digester. The engine is still can be run to provide electricity by using conventional fuel such as LPG or gasoline. The full consumption as well as emission of this flexible fuel engine was investigated. It is found that the fuel consumption is 9.97 L/mint for Biogas, 0.004 L/mint for gasoline and 2.24 L/mint for LPG. Surprisingly by using biogas the emission of carbon monoxide (CO) was down to almost zero (0.02 ppm), comparing gasoline 0.32 ppm, and LPG 0.4 ppm.


2021 ◽  
Author(s):  
Saeideh Heshmati ◽  
Zita Oravecz

Most assessments of well-being have relied on retrospective accounts, measured by global evaluative well-being scales. Following the recent debates focused on the assessment of hedonic and eudaimonic well-being based on the elements of the PERMA theory, the current study aimed to shed further light onto the measurement of PERMA elements in daily life and their temporal dynamics. Through an Ecological Momentary Assessment (EMA) design (N=160), we examined the dynamics of change (e.g., baselines and intra-individual variability) in the PERMA elements using the mPERMA measure, which is an EMA-adapted version of the PERMA Profiler. Findings revealed that momentary experiences of well-being, quantified via PERMA elements, map onto their corresponding hedonic or eudaimonic well-being components, and its dynamical features provide novel insights into predicting global well-being. This work offers avenues for future research to assess well-being in real-time and real-world contexts in ecologically valid ways, while eliminating recall bias.


2011 ◽  
Vol 89 (7) ◽  
pp. 845-853 ◽  
Author(s):  
Sadok Letaief ◽  
Wendy Pell ◽  
Christian Detellier

The clay mineral kaolinite was used as support of gold nanoparticles for heterogeneous catalysis of oxidation reactions, particularly of carbon monoxide oxidation. The application of clay minerals in the preparation of new functional materials provides an alternative approach for the use of these abundant raw materials. To improve the physicochemical properties of kaolinite, as well as to ensure a strong immobilization of the adsorbed species, kaolinite was functionalized by grafting 2-amino-2-methyl-1,3-propanediol on the internal and external surfaces of the octahedral sheets by reaction with the aluminol groups. Gold nanoparticles were then deposited on the external surfaces of the fine particles of the functionalized kaolinite. The resulting gold kaolinite nanohybrid material was characterized by various physicochemical techniques. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry confirmed that gold was effectively reduced to the metallic state during adsorption onto the external surfaces of the modified kaolinite. The gold nanoparticles have a narrow size distribution: more than 88% are less than 4 nm in diameter. Gold nanoparticles deposited on kaolinite catalyze the electro-oxidation of carbon monoxide in alkaline solution at room temperature.


2021 ◽  
Vol 1 (1) ◽  
pp. 50-69
Author(s):  
Wilson Uzochukwu Eze ◽  
◽  
Reginald Umunakwe ◽  
Henry Chinedu Obasi ◽  
Michael Ifeanyichukwu Ugbaja ◽  
...  

<abstract> <p>The world is today faced with the problem of plastic waste pollution more than ever before. Global plastic production continues to accelerate, despite the fact that recycling rates are comparatively low, with only about 15% of the 400 million tonnes of plastic currently produced annually being recycled. Although recycling rates have been steadily growing over the last 30 years, the rate of global plastic production far outweighs this, meaning that more and more plastic is ending up in dump sites, landfills and finally into the environment, where it damages the ecosystem. Better end-of-life options for plastic waste are needed to help support current recycling efforts and turn the tide on plastic waste. A promising emerging technology is plastic pyrolysis; a chemical process that breaks plastics down into their raw materials. Key products are liquid resembling crude oil, which can be burned as fuel and other feedstock which can be used for so many new chemical processes, enabling a closed-loop process. The experimental results on the pyrolysis of thermoplastic polymers are discussed in this review with emphasis on single and mixed waste plastics pyrolysis liquid fuel.</p> </abstract>


2014 ◽  
Vol 3 (4) ◽  
pp. 44-56
Author(s):  
Kanza Abid ◽  
Zafar Iqbal Shams

Many processes in the iron and steel making industries emit carbon monoxide, which causes a variety of toxic effects on human health, such as fatigue, impaired memory, headache, and nausea. At elevated exposure, carbon monoxide poisoning may lead to loss of consciousness and death. Therefore, the current study has been carried out to investigate the occupational exposure of randomly selected fifty-eight employees of Pakistan Steel Mills to the carbon monoxide. The selected employees were from 10 different facilities of the Pakistan Steel Mills, who were working in two different shifts viz. nightshift and dayshift, each of twelve hours. Thirty employees from nightshift and twenty-eight employees from dayshift were monitored for their exposure to carbon monoxide. The instrument was logged to measure the employee’s exposure to carbon monoxide with 1-minute interval. The study reveals that the employees, working in the Raw Materials Production Plant during nightshift were exposed to the highest mean concentration of carbon monoxide while those working in Oxygen Plant during nightshift were exposed to the lowest mean concentration of carbon monoxide. According to study, the highest recorded exposure was found near Blast Furnace during dayshift. The employees’ exposure to 98th percentile concentration of carbon monoxide in different facilities of the steel mills has also been analyzed. The employees’ exposure to carbon monoxide during commuting from home to their workplace has also been investigated.DOI: http://dx.doi.org/10.3126/ije.v3i4.11730      International Journal of EnvironmentVolume-3, Issue-4, Sep-Nov 2014Page: 44-56


2020 ◽  
Vol 1 (3) ◽  
pp. 275-289
Author(s):  
Alessa Hinzmann ◽  
Selina Sophie Druhmann ◽  
Harald Gröger

Currently, investigations of polymer-building blocks made from biorenewable feedstocks such as, for example, fatty acids, are of high interest for the chemical industry. An alternative synthesis of nitrile-substituted aliphatic carboxylic acids as precursors for ω-amino acids, which are useful to produce polymers, was investigated starting from biorenewable fatty acids. By hydroformylation of unsaturated fatty acids or unsaturated acids being accessible from unsaturated fatty acids by cross-metathesis reactions, aldehydes are formed. In this work, the hydroformylation of such unsaturated acids led to the formation of the corresponding aldehydes, which were afterwards converted with hydroxylamine to aldoximes. Subsequent dehydration by an aldoxime dehydratase as a biocatalyst or by CuII acetate led to the desired nitriles. Within this work, C7-, C9- and C11-carboxylic acids with a terminal nitrile functionality as well as a branched nitrile-functionalized stearate derivative were synthesized by means of this approach. As these nitriles serve as precursors for amino acids being suitable for polymerization, this work represents an alternative synthetic access to polyamide precursors, which starts directly from unsaturated fatty acids as biorenewable resources and avoids harsh reaction conditions as well as and by-product formation.


Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 895
Author(s):  
Aitziber Iriondo ◽  
Ion Agirre ◽  
Nerea Viar ◽  
Jesús Requies

The depletion of fossil resources in the near future and the need to decrease greenhouse gas emissions lead to the investigation of using alternative renewable resources as raw materials. One of the most promising options is the conversion of lignocellulosic biomass (like forestry residues) into bioenergy, biofuels and biochemicals. Among these products, the production of intermediate biochemicals has become an important goal since the petrochemical industry needs to find sustainable alternatives. In this way, the chemical industry competitiveness could be improved as bioproducts have a great potential market. Thus, the main objective of this review is to describe the production processes under study (reaction conditions, type of catalysts, solvents, etc.) of some promising intermediate biochemicals, such as; alcohols (1,2,6-hexanetriol, 1,6-hexanetriol and pentanediols (1,2 and 1,5-pentanediol)), maleic anhydride and 5-alkoxymethylfuran. These compounds can be produced using 5-hydroxymethylfurfural and/or furfural, which they both are considered one of the main biomass derived building blocks.


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