scholarly journals Rapid mechanoenzymatic saccharification of lignocellulosic biomass without bulk water or chemical pre-treatment

2020 ◽  
Author(s):  
Fabien Hammerer ◽  
Shaghayegh Ostadjoo ◽  
Karolin Dietrich ◽  
Marie-Josée Dumont ◽  
Luis F. Del Rio ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Large Scale ◽  
Enzymatic Reaction ◽  
Renewable Resource ◽  
Bulk Water ◽  
Biomass Saccharification ◽  
Crude Product ◽  
Fuels And Chemicals ◽  
Multiple Cycles ◽  
Pre Treatment

AbstractLignocellulosic material is an abundant renewable resource with the potential to replace petroleum as a feedstock for the production of fuels and chemicals. The large scale deployment of biomass saccharification is, however, hampered by the necessity to use aggressive reagents and conditions, formation of side-products, and the difficulty to reach elevated monosaccharide concentrations in the crude product. Herein we report the high efficacy of Reactive Aging (or Raging, a technique where enzymatic reaction mixtures, without any bulk aqueous or organic solvent, are treated to multiple cycles of milling and aging) for gram-scale saccharification of raw lignocellulosic biomass samples from different agricultural sources (corn stover, wheat straw, and sugarcane bagasse). The solvent-free enzymatic conversion of lignocellulosic biomass was found to proceed in excellent yields (ca. 90%) at protein loadings as low as 2% w/w, without the need for any prior chemical pre-treatment or high temperatures, to produce highly concentrated (molar) monosaccharides. This crude product of mechanoenzymatic depolymerization is non-toxic to bacteria and can be used as a carbon source for bacterial growth.

Microbial Oil Production from Lignocellulosic Biomass – Recent Development and Prospect

2014 ◽  
Vol 541-542 ◽  
pp. 397-403
Author(s):  
Zhang Nan Lin ◽  
Hong Juan Liu ◽  
Zhi Qin Wang ◽  
Jia Nan Zhang
Keyword(s):  
Lignocellulosic Biomass ◽  
Large Scale ◽  
Raw Materials ◽  
Oil Production ◽  
Renewable Resource ◽  
Raw Material ◽  
Biodiesel Production ◽  
Microbial Oil ◽  
Key Issues ◽  
Application Potential

Microbial oil is one of the ideal raw materials for biodiesel production because of its rapid reproduction and less influence by the climate and season variation. However, the high cost is one of the key issues that restricted its production in a large-scale. Lignocellulosic biomass, the cheap and renewable resource, might be the best raw material for microbial oil production by oleaginous microorganisms. Recent development on the microbial oil production from lignocellulosic biomass was summarized in this paper. Furthermore, the challenges and application potential of microbial oil were prospected.

scholarly journals Rapid mechanoenzymatic saccharification of lignocellulosic biomass without bulk water or chemical pre-treatment

2020 ◽  
Vol 22 (12) ◽  
pp. 3877-3884
Author(s):  
Fabien Hammerer ◽  
Shaghayegh Ostadjoo ◽  
Karolin Dietrich ◽  
Marie-Josée Dumont ◽  
Luis F. Del Rio ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Bulk Water ◽  
Fermentable Sugars ◽  
Solid Reaction ◽  
Pre Treatment

Enzymes can be used in moist solid reaction mixtures to effectively depolymerize biomass to fermentable sugars.

scholarly journals Pretreatment of Lignocellulosic Materials as Substrates for Fermentation Processes

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2937 ◽  
Author(s):  
Karolina Kucharska ◽  
Piotr Rybarczyk ◽  
Iwona Hołowacz ◽  
Rafał Łukajtis ◽  
Marta Glinka ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Organic Compounds ◽  
Large Scale ◽  
Fossil Fuels ◽  
Cost Effective ◽  
Renewable Resource ◽  
Biomass Pretreatment ◽  
Lignocellulosic Materials ◽  
Fermentation Processes ◽  
Cellulose Digestibility

Lignocellulosic biomass is an abundant and renewable resource that potentially contains large amounts of energy. It is an interesting alternative for fossil fuels, allowing the production of biofuels and other organic compounds. In this paper, a review devoted to the processing of lignocellulosic materials as substrates for fermentation processes is presented. The review focuses on physical, chemical, physicochemical, enzymatic, and microbiologic methods of biomass pretreatment. In addition to the evaluation of the mentioned methods, the aim of the paper is to understand the possibilities of the biomass pretreatment and their influence on the efficiency of biofuels and organic compounds production. The effects of different pretreatment methods on the lignocellulosic biomass structure are described along with a discussion of the benefits and drawbacks of each method, including the potential generation of inhibitory compounds for enzymatic hydrolysis, the effect on cellulose digestibility, the generation of compounds that are toxic for the environment, and energy and economic demand. The results of the investigations imply that only the stepwise pretreatment procedure may ensure effective fermentation of the lignocellulosic biomass. Pretreatment step is still a challenge for obtaining cost-effective and competitive technology for large-scale conversion of lignocellulosic biomass into fermentable sugars with low inhibitory concentration.

scholarly journals Choosing Physical, Physicochemical and Chemical Methods of Pre-Treating Lignocellulosic Wastes to Repurpose into Solid Fuels

2019 ◽  
Vol 11 (13) ◽  
pp. 3604 ◽  
Author(s):  
Martin Taylor ◽  
Hassan Alabdrabalameer ◽  
Vasiliki Skoulou
Keyword(s):  
Lignocellulosic Biomass ◽  
Large Scale ◽  
Relevant Literature ◽  
Scale Up ◽  
Value Added ◽  
Solid Fuels ◽  
Biomass Waste ◽  
True Value ◽  
Pre Treatment ◽  
Downstream Processes

Various methods of physical, chemical and combined physicochemical pre-treatments for lignocellulosic biomass waste valorisation to value-added feedstock/solid fuels for downstream processes in chemical industries have been reviewed. The relevant literature was scrutinized for lignocellulosic waste applicability in advanced thermochemical treatments for either energy or liquid fuels. By altering the overall naturally occurring bio-polymeric matrix of lignocellulosic biomass waste, individual components such as cellulose, hemicellulose and lignin can be accessed for numerous downstream processes such as pyrolysis, gasification and catalytic upgrading to value-added products such as low carbon energy. Assessing the appropriate lignocellulosic pre-treatment technology is critical to suit the downstream process of both small- and large-scale operations. The cost to operate the process (temperature, pressure or energy constraints), the physical and chemical structure of the feedstock after pre-treatment (decomposition/degradation, removal of inorganic components or organic solubilization) or the ability to scale up the pre-treating process must be considered so that the true value in the use of bio-renewable waste can be revealed.

Lignocellulosic biomass for bioethanol: an overview on pretreatment, hydrolysis and fermentation processes

2019 ◽  
Vol 34 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Bodjui Olivier Abo ◽  
Ming Gao ◽  
Yonglin Wang ◽  
Chuanfu Wu ◽  
Hongzhi Ma ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Lignocellulosic Biomass ◽  
Greenhouse Effect ◽  
Sugar Cane ◽  
Large Scale ◽  
Low Cost ◽  
Agricultural Residues ◽  
High Availability ◽  
Fermentation Processes ◽  
Pre Treatment

Abstract Bioethanol is currently the only alternative to gasoline that can be used immediately without having to make any significant changes in the way fuel is distributed. In addition, the carbon dioxide (CO2) released during the combustion of bioethanol is the same as that used by the plant in the atmosphere for its growth, so it does not participate in the increase of the greenhouse effect. Bioethanol can be obtained by fermentation of plants containing sucrose (beet, sugar cane…) or starch (wheat, corn…). However, large-scale use of bioethanol implies the use of very large agricultural surfaces for maize or sugarcane production. Lignocellulosic biomass (LCB) such as agricultural residues for the production of bioethanol seems to be a solution to this problem due to its high availability and low cost even if its growth still faces technological difficulties. In this review, we present an overview of lignocellulosic biomass, the different methods of pre-treatment of LCB and the various fermentation processes that can be used to produce bioethanol from LCB.

Reuse of Wastewaters in Agriculture by Means of Sprinkler Irrigation on a Farmland Area of 3000 ha – Large Scale Experience in Germany

1986 ◽  
Vol 18 (9) ◽  
pp. 163-173
Author(s):  
R. Boll ◽  
R. Kayser
Keyword(s):  
Large Scale ◽  
Treatment Process ◽  
Treatment Plant ◽  
Sprinkler Irrigation ◽  
Paper Briefly ◽  
Treatment Results ◽  
Sewage Farm ◽  
Western Germany ◽  
Pre Treatment ◽  
Main Components

The Braunschweig wastewater land treatment system as the largest in Western Germany serves a population of about 270.000 and has an annual flow of around 22 Mio m3. The whole treatment process consists of three main components : a pre-treatment plant as an activated sludge process, a sprinkler irrigation area of 3.000 ha of farmland and an old sewage farm of 200 ha with surface flooding. This paper briefly summarizes the experiences with management and operation of the system, the treatment results with reference to environmental impact, development of agriculture and some financial aspects.

Use of lime for the upgrading of existing wastewater treatment systems

1994 ◽  
Vol 29 (12) ◽  
pp. 279-282 ◽  
Author(s):  
C. Güldner ◽  
W. Hegemann ◽  
N. Peschen ◽  
K. Sölter
Keyword(s):  
Large Scale ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Precipitation ◽  
Fatty Acid Production ◽  
German States ◽  
Lime Solution ◽  
First Results ◽  
Pre Treatment

The integration of the chemical precipitation unit which would inject a lime solution into a series of mechanical-biological processes, including nitrification/denitrification, and the sludge treatment are the subject of this project. The essential target is the large-scale reconstruction of a mechanical-biological sewage treatment plant with insufficient cleaning performance in the new German states and the adjustment of the precipitation stage to the unsteady inflow of sewage. First results indicate that the pre-treatment performance could be improved by ≅ 20% and the discharge of concentrations of COD, BOD, N and P could be reduced and homogenized. In addition, experiments on hydrolysis and acidifiability of the pre-treatment sludge have been carried out on a laboratory level with the object of making sources of carbon readily available for denitrification. In the course of the experiment, inhibition of fatty acid production by calcareous primary sludge could not be detected. The characteristics of the sludge, such as draining and thickening were considerably improved by the adding of lime.

scholarly journals Further engineering of R. toruloides for the production of terpenes from lignocellulosic biomass

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
James Kirby ◽  
Gina M. Geiselman ◽  
Junko Yaegashi ◽  
Joonhoon Kim ◽  
Xun Zhuang ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Copy Number ◽  
Mevalonate Pathway ◽  
Mevalonate Kinase ◽  
Metabolite Analysis ◽  
Lignocellulosic Hydrolysate ◽  
Microbial Conversion ◽  
Lignocellulosic Hydrolysates ◽  
Lignocellulosic Feedstocks ◽  
Fuels And Chemicals

Abstract Background Mitigation of climate change requires that new routes for the production of fuels and chemicals be as oil-independent as possible. The microbial conversion of lignocellulosic feedstocks into terpene-based biofuels and bioproducts represents one such route. This work builds upon previous demonstrations that the single-celled carotenogenic basidiomycete, Rhodosporidium toruloides, is a promising host for the production of terpenes from lignocellulosic hydrolysates. Results This study focuses on the optimization of production of the monoterpene 1,8-cineole and the sesquiterpene α-bisabolene in R. toruloides. The α-bisabolene titer attained in R. toruloides was found to be proportional to the copy number of the bisabolene synthase (BIS) expression cassette, which in turn influenced the expression level of several native mevalonate pathway genes. The addition of more copies of BIS under a stronger promoter resulted in production of α-bisabolene at 2.2 g/L from lignocellulosic hydrolysate in a 2-L fermenter. Production of 1,8-cineole was found to be limited by availability of the precursor geranylgeranyl pyrophosphate (GPP) and expression of an appropriate GPP synthase increased the monoterpene titer fourfold to 143 mg/L at bench scale. Targeted mevalonate pathway metabolite analysis suggested that 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR), mevalonate kinase (MK) and phosphomevalonate kinase (PMK) may be pathway bottlenecks are were therefore selected as targets for overexpression. Expression of HMGR, MK, and PMK orthologs and growth in an optimized lignocellulosic hydrolysate medium increased the 1,8-cineole titer an additional tenfold to 1.4 g/L. Expression of the same mevalonate pathway genes did not have as large an impact on α-bisabolene production, although the final titer was higher at 2.6 g/L. Furthermore, mevalonate pathway intermediates accumulated in the mevalonate-engineered strains, suggesting room for further improvement. Conclusions This work brings R. toruloides closer to being able to make industrially relevant quantities of terpene from lignocellulosic biomass.

scholarly journals Tyrosinase Nanoparticles: Understanding the Melanogenesis Pathway by Isolating the Products of Tyrosinase Enzymatic Reaction

2021 ◽  
Vol 22 (2) ◽  
pp. 734
Author(s):  
Paul K. Varghese ◽  
Mones Abu-Asab ◽  
Emilios K. Dimitriadis ◽  
Monika B. Dolinska ◽  
George P. Morcos ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Large Scale ◽  
Magnetic Beads ◽  
Enzymatic Reaction ◽  
Oculocutaneous Albinism ◽  
Transmission Electron ◽  
Hill Kinetics ◽  
Rate Limiting ◽  
Human Tyrosinase

Human Tyrosinase (Tyr) is the rate-limiting enzyme of the melanogenesis pathway. Tyr catalyzes the oxidation of the substrate L-DOPA into dopachrome and melanin. Currently, the characterization of dopachrome-related products is difficult due to the absence of a simple way to partition dopachrome from protein fraction. Here, we immobilize catalytically pure recombinant human Tyr domain (residues 19–469) containing 6xHis tag to Ni-loaded magnetic beads (MB). Transmission electron microscopy revealed Tyr-MB were within limits of 168.2 ± 24.4 nm while the dark-brown melanin images showed single and polymerized melanin with a diameter of 121.4 ± 18.1 nm. Using Hill kinetics, we show that Tyr-MB has a catalytic activity similar to that of intact Tyr. The diphenol oxidase reactions of L-DOPA show an increase of dopachrome formation with the number of MB and with temperature. At 50 °C, Tyr-MB shows some residual catalytic activity suggesting that the immobilized Tyr has increased protein stability. In contrast, under 37 °C, the dopachrome product, which is isolated from Tyr-MB particles, shows that dopachrome has an orange-brown color that is different from the color of the mixture of L-DOPA, Tyr, and dopachrome. In the future, Tyr-MB could be used for large-scale productions of dopachrome and melanin-related products and finding a treatment for oculocutaneous albinism-inherited diseases.

The assessment of density functionals for DNA–protein stacked and T-shaped complexes

2010 ◽  
Vol 88 (8) ◽  
pp. 815-830 ◽  
Author(s):  
Lesley R. Rutledge ◽  
Stacey D. Wetmore
Keyword(s):  
Amino Acid ◽  
Potential Energy ◽  
Large Scale ◽  
Enzymatic Reaction ◽  
Basis Sets ◽  
Density Functionals ◽  
Interaction Energies ◽  
Π Interactions ◽  
Hybrid Techniques ◽  
Semi Empirical

The present work uses 129 nucleobase – amino acid CCSD(T)/CBS stacking and T-shaped interaction energies as reference data to test the ability of various density functionals with double-zeta quality basis sets, as well as some semi-empirical and molecular mechanics methods, to accurately describe noncovalent DNA–protein π–π and π+–π interactions. The goal of this work is to identify methods that can be used in hybrid approaches (QM/MM, ONIOM) for large-scale modeling of enzymatic systems involving active-site (substrate) π–π contacts. Our results indicate that AMBER is a more appropriate choice for the lower-level method in hybrid techniques than popular semi-empirical methods (AM1, PM3), and suggest that AMBER accurately describes the π–π interactions found throughout DNA–protein complexes. The M06–2X and PBE-D density functionals were found to provide very promising descriptions of the 129 nucleobase – amino acid interaction energies, which suggests that these may be the most suitable methods for describing high-level regions. Therefore, M06–2X and PBE-D with both the 6–31G(d) and 6–31+G(d,p) basis sets were further examined through potential-energy surface scans to better understand how these techniques describe DNA–protein π–π interactions in both minimum and nonminimum regions of the potential-energy surfaces, which is critical information when modeling enzymatic reaction pathways. Our results suggest that studies of stacked nucleobase – amino acid systems should implement the PBE-D/6–31+G(d,p) method. However, if T-shaped contacts are involved and (or) smaller basis sets must be considered due to limitations in computational resources, then M06–2X/6–31G(d) provides an overall excellent description of both nucleobase – amino acid stacking and T-shaped interactions for a range of DNA–protein π–π and π+–π interactions.

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