Design of a Synthetic Enzyme Cascade for the in vitro Fixation of a C1 Carbon Source to a Functional C4 Sugar

2021 ◽  
Author(s):  
Samed Güner ◽  
Vanessa Wegat ◽  
André Pick ◽  
Volker Sieber

Realizing a sustainable future requires intensifying the waste stream conversion, such as converting the greenhouse gas carbon dioxide into value-added products. In this paper, we focus on utilizing formaldehyde as...

2021 ◽  
Author(s):  
Wenbo Wang ◽  
Runqing Lu ◽  
Xin-Xin Xiao ◽  
Shanhe Gong ◽  
Daniel Kobina Sam ◽  
...  

Electrochemical carbon dioxide reduction reaction (eCO2RR) is a promising technology that uses electrical energy to catalytically reduce the greenhouse gas-CO2, which can convert CO2 into high value-added products such as...


2018 ◽  
Vol 260 ◽  
pp. 68-75 ◽  
Author(s):  
Pavlo Bohutskyi ◽  
Leo A. Kucek ◽  
Eric Hill ◽  
Grigoriy E. Pinchuk ◽  
Sagadevan G. Mundree ◽  
...  

2022 ◽  
Vol 10 (1) ◽  
pp. 184
Author(s):  
Izumi Orita ◽  
Gento Unno ◽  
Risa Kato ◽  
Toshiaki Fukui

Methylorubrum extorquens AM1 is the attractive platform for the production of value-added products from methanol. We previously demonstrated that M. extorquens equipped with PHA synthase with broad substrate specificity synthesized polyhydroxyalkanoates (PHAs) composed of (R)-3-hydroxybutyrate and small fraction of (R)-3-hydroxyvalerate (3HV) and (R)-3-hydroxyhexanoate (3HHx) units on methanol. This study further engineered M. extorquens for biosynthesis of PHAs with higher 3HV and 3HHx composition focusing on the EMC pathway involved in C1 assimilation. The introduction of ethylmalonyl-CoA decarboxylase, catalyzing a backward reaction in the EMC pathway, aiming to increase intracellular propionyl/butyryl-CoA precursors did not affect PHA composition. Reverse b-oxidation pathway and subsequent (R)-specific hydration of 2-enoyl-CoA were then enhanced by heterologous expression of four genes derived from Ralstonia eutropha for the conversion of propionyl/butyryl-CoAs to the corresponding (R)-3-hydroxyacyl-CoA monomers. The resulting strains produced PHAs with higher 3HV and 3HHx compositions, while the methylotrophic growth was severely impaired. This growth impairment was interestingly restored by the addition of La3+ without a negative impact on PHA biosynthesis, suggesting the activation of the EMC pathway by La3+. The engineered M. extorquens synthesized PHA terpolymer composed of 5.4 mol% 3HV and 0.9% of 3HHx with 41% content from methanol as a sole carbon source in the presence of La3+.


RSC Advances ◽  
2015 ◽  
Vol 5 (5) ◽  
pp. 3581-3589 ◽  
Author(s):  
Surya Singh ◽  
Bedika Phukan ◽  
Chandan Mukherjee ◽  
Anil Verma

CO2, being a linear and centrosymmetric molecule, is very stable, and the electrochemical reduction of CO2 requires energy. However, the salen complexes are found to be very efficient to minimize overpotential as compared to their metal counterparts.


2018 ◽  
Vol 9 (11) ◽  
pp. 2952-2960 ◽  
Author(s):  
Eva M. Nichols ◽  
Jeffrey S. Derrick ◽  
Sepand K. Nistanaki ◽  
Peter T. Smith ◽  
Christopher J. Chang

The development of catalysts for electrochemical reduction of carbon dioxide offers an attractive approach to transforming this greenhouse gas into value-added carbon products with sustainable energy input.


Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 413 ◽  
Author(s):  
Silvia Mena ◽  
Iluminada Gallardo ◽  
Gonzalo Guirado

Carbon dioxide (CO2) is a known greenhouse gas, and is the most important contributor to global warming. Therefore, one of the main challenges is to either eliminate or reuse it through the synthesis of value-added products, such as carboxylated derivatives. One of the most promising approaches for activating, capturing, and valorizing CO2 is the use of electrochemical techniques. In the current manuscript, we described an electrocarboxylation route for synthesizing 4-cyanobenzoic acid by valorizing CO2 through the synergistic use of electrochemical techniques (“green technology”) and ionic liquids (ILs) (“green solvents”)—two of the major entries in the general green chemistry tool kit. Moreover, the use of silver cathodes and ILs enabled the electrochemical potential applied to be reduced by more than 0.4 V. The “green” synthesis of those derivatives would provide a suitable environmentally friendly process for the design of plasticizers based on phthalate derivatives.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Manuel Nieto-Domínguez ◽  
José Alberto Martínez-Fernández ◽  
Beatriz Fernández de Toro ◽  
Juan A. Méndez-Líter ◽  
Francisco Javier Cañada ◽  
...  

Abstract Background Currently, industrial societies are seeking for green alternatives to conventional chemical synthesis. This demand has merged with the efforts to convert lignocellulosic biomass into value-added products. In this context, xylan, as one of main components of lignocellulose, has emerged as a raw material with high potential for advancing towards a sustainable economy. Results In this study, the recombinant endoxylanase rXynM from the ascomycete Talaromyces amestolkiae has been heterologously expressed in Pichia pastoris and used as one of the catalysts of an enzyme cascade developed to synthesize the antiproliferative 2-(6-hydroxynaphthyl) β-d-xylopyranoside, by transglycosylation of 2,6-dihydroxynaphthalene. The approach combines the use of two fungal xylanolytic enzymes, rXynM and the β-xylosidase rBxTW1 from the same fungus, with the cost-effective substrate xylan. The reaction conditions for the cascade were optimized by a Central Composite Design. Maximal productions of 0.59 and 0.38 g/L were reached using beechwood xylan and birchwood xylan, respectively. For comparison, xylans from other sources were tested in the same reaction, suggesting that a specific optimization is required for each xylan variety. The results obtained using this enzyme cascade and xylan were similar or better to those previously reported for a single catalyst and xylobiose, an expensive sugar donor. Conclusions Beechwood and birchwood xylan, two polysaccharides easily available from biomass, were used in a novel enzyme cascade to synthetize an antiproliferative agent. The approach represents a green alternative to the conventional chemical synthesis of 2-(6-hydroxynaphthyl) β-d-xylopyranoside using a cost-effective substrate. The work highlights the role of xylan as a raw material for producing value-added products and the potential of fungal xylanolytic enzymes in the biomass conversion.


2020 ◽  
Vol 5 (2) ◽  
pp. 486-519 ◽  
Author(s):  
Vignesh Kumaravel ◽  
John Bartlett ◽  
Suresh C. Pillai

2020 ◽  
Vol 13 (12) ◽  
pp. 2156-2171
Author(s):  
Leonardo Setti ◽  
Seyedeh Parya Samaei ◽  
Irene Maggiore ◽  
Lorenzo Nissen ◽  
Andrea Gianotti ◽  
...  

AbstractHemp (Cannabis sativa L.) seeds are considered a nutritional powerhouse, rich in proteins and unsaturated fatty acids. The market for hemp seed food products is growing, due to the loosening of constraints in industrial cultivation. During the food processing chain, the external part of the seed is discarded, although it contains a significant amount of proteins. Converting this material into value-added products with a biorefinery approach could meet the ever-increasing need for sustainable protein sources while reducing food waste. In this study, creating value from hemp byproducts was pursued with three different approaches: (i) chemical extraction followed by enzymatic digestion, (ii) liquid fermentation by strains of Lactobacillus spp., and (iii) solid-state fermentation by Pleurotus ostreatus. The resulting products exhibited a range of in vitro antioxidant and antihypertensive activity, depending on the proteases used for enzymatic digestion, the bacterial strain, and the length of time of the two fermentation processes. These byproducts could be exploited as functional ingredients in the food, pharmaceutical, and cosmetic industries; the suggested biorefinery processes thus represent potential solutions for the development of other protein-containing byproducts or wastes.


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