scholarly journals Eco-friendly additives in acidic pretreatment to boost enzymatic saccharification of hardwood for sustainable biorefinery applications

2021 ◽  
Author(s):  
Qiulu Chu ◽  
Wenyao Tong ◽  
Shufang Wu ◽  
Yongcan Jin ◽  
Jinguang Hu ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Enzymatic Saccharification ◽  
Fermentable Sugars ◽  
Acidic Pretreatment

Pretreatment of renewable lignocellulosic biomass is essential to produce fermentable sugars and biofuels in a sustainable biorefinery. However, lignin repolymerization during pretreatment was reported to intensify the lignin inhibition on...

scholarly journals LPMO AfAA9_B and Cellobiohydrolase AfCel6A from A. fumigatus Bost Enzymatic Saccharification Activity of Cellulase Cocktail

2020 ◽  
Author(s):  
Taisa Magnani Dinamarco ◽  
Aline Vianna Bernardi ◽  
Luis Eduardo Gerolamo ◽  
Paula Fagundes de Gouvêa ◽  
Deborah Kimie Yonamine ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Lignocellulosic Biomass ◽  
Filamentous Fungi ◽  
Biochemical Parameters ◽  
Enzymatic Saccharification ◽  
Fermentable Sugars ◽  
Optimal Temperature ◽  
High Turnover ◽  
Lytic Polysaccharide Monooxygenase ◽  
Polysaccharide Monooxygenase

Cellulose is the most abundant polysaccharide in lignocellulosic biomass, where it is interlinked with lignin and hemicellulose. Bioethanol can be produced from biomass. Because breaking down biomass is difficult, cellulose-active enzymes secreted by filamentous fungi play an important role in degrading recalcitrant lignocellulosic biomass. We characterized a cellobiohydrolase (AfCel6A) and lytic polysaccharide monooxygenase LPMO (AfAA9_B) from A. fumigatus after they were expressed in Pichia pastoris and purified. The biochemical parameters suggested that the enzymes were stable; the optimal temperature was ~60 °C. Further characterization revealed high turnover numbers (kcat of 147.9 s-1 and 0.64 s-1, respectively). Surprisingly, when combined, AfCel6A and AfAA9_B did not act synergistically. Association of AfCel6A and AfAA9_B inhibits the activity of AfCel6A, an outcome that needs to be further investigated. However, addition of AfCel6A or AfAA9_B boosts the enzymatic saccharification activity of a cellulase cocktail and the activity of cellulase Af-EGL7. The supplementation of an enzymatic cocktail with AfCel6A or AfAA9_B boosted the yield of fermentable sugars from complex substrates, especially sugarcane exploded bagasse, by up to 95%. The synergism between the cellulase cocktail and AfAA9_B is enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass.

scholarly journals LPMO AfAA9_B and Cellobiohydrolase AfCel6A from A. fumigatus Boost Enzymatic Saccharification Activity of Cellulase Cocktail

2020 ◽  
Vol 22 (1) ◽  
pp. 276
Author(s):  
Aline Vianna Bernardi ◽  
Luis Eduardo Gerolamo ◽  
Paula Fagundes de Gouvêa ◽  
Deborah Kimie Yonamine ◽  
Lucas Matheus Soares Pereira ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Aspergillus Fumigatus ◽  
Lignocellulosic Biomass ◽  
Biochemical Parameters ◽  
Enzymatic Saccharification ◽  
Fermentable Sugars ◽  
Optimal Temperature ◽  
High Turnover ◽  
Lytic Polysaccharide Monooxygenase ◽  
Polysaccharide Monooxygenase

Cellulose is the most abundant polysaccharide in lignocellulosic biomass, where it is interlinked with lignin and hemicellulose. Bioethanol can be produced from biomass. Since breaking down biomass is difficult, cellulose-active enzymes secreted by filamentous fungi play an important role in degrading recalcitrant lignocellulosic biomass. We characterized a cellobiohydrolase (AfCel6A) and lytic polysaccharide monooxygenase LPMO (AfAA9_B) from Aspergillus fumigatus after they were expressed in Pichia pastoris and purified. The biochemical parameters suggested that the enzymes were stable; the optimal temperature was ~60 °C. Further characterization revealed high turnover numbers (kcat of 147.9 s−1 and 0.64 s−1, respectively). Surprisingly, when combined, AfCel6A and AfAA9_B did not act synergistically. AfCel6A and AfAA9_B association inhibited AfCel6A activity, an outcome that needs to be further investigated. However, AfCel6A or AfAA9_B addition boosted the enzymatic saccharification activity of a cellulase cocktail and the activity of cellulase Af-EGL7. Enzymatic cocktail supplementation with AfCel6A or AfAA9_B boosted the yield of fermentable sugars from complex substrates, especially sugarcane exploded bagasse, by up to 95%. The synergism between the cellulase cocktail and AfAA9_B was enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass by up to 95%. The synergism between the cellulase cocktail and AfAA9_B was enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass.

scholarly journals Bioreactor and Bioprocess Design Issues in Enzymatic Hydrolysis of Lignocellulosic Biomass

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 680
Author(s):  
Giuseppe Olivieri ◽  
René H. Wijffels ◽  
Antonio Marzocchella ◽  
Maria Elena Russo
Keyword(s):  
Lignocellulosic Biomass ◽  
Enzymatic Saccharification ◽  
Product Inhibition ◽  
Cellulolytic Enzymes ◽  
Main Process ◽  
Bioprocess Design ◽  
Operating Modes ◽  
Biomass Saccharification ◽  
Starting Point ◽  
The Impact

Saccharification of lignocellulosic biomass is a fundamental step in the biorefinery of second generation feedstock. The physicochemical and enzymatic processes for the depolymerization of biomass into simple sugars has been achieved through numerous studies in several disciplines. The present review discusses the development of technologies for enzymatic saccharification in industrial processes. The kinetics of cellulolytic enzymes involved in polysaccharide hydrolysis has been discussed as the starting point for the design of the most promising bioreactor configurations. The main process configurations—proposed so far—for biomass saccharification have been analyzed. Attention was paid to bioreactor configurations, operating modes and possible integrations of this operation within the biorefinery. The focus is on minimizing the effects of product inhibition on enzymes, maximizing yields and concentration of sugars in the hydrolysate, and reducing the impact of enzyme cost on the whole process. The last part of the review is focused on an emerging process based on the catalytic action of laccase applied to lignin depolymerization as an alternative to the consolidated physicochemical pretreatments. The laccases-based oxidative process has been discussed in terms of characteristics that can affect the development of a bioreactor unit where laccases or a laccase-mediator system can be used for biomass delignification.

Comparison of Chemical Pretreatment for Recovery of Fermentable Sugars and Enzymatic Saccharification

2017 ◽  
Vol 104 (7-9) ◽  
pp. 273 ◽  
Author(s):  
Maheshwari Packiam ◽  
Karthikeyan Subburamu ◽  
Ramesh Desikan ◽  
Sivakumar Uthandi ◽  
Marimuthu Subramanian ◽  
...  
Keyword(s):  
Enzymatic Saccharification ◽  
Fermentable Sugars ◽  
Chemical Pretreatment

scholarly journals Fuzzy-Enhanced Modeling of Lignocellulosic Biomass Enzymatic Saccharification

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2110
Author(s):  
Vitor B. Furlong ◽  
Luciano J. Corrêa ◽  
Roberto C. Giordano ◽  
Marcelo P. A. Ribeiro
Keyword(s):  
Lignocellulosic Biomass ◽  
Enzymatic Saccharification ◽  
Fuzzy Model ◽  
Fuzzy Rule ◽  
Batch Processes ◽  
Validation Data ◽  
Data Set ◽  
Physico Chemical ◽  
Takagi Sugeno ◽  
Simple Models

The enzymatic hydrolysis of lignocellulosic biomass incorporates many physico-chemical phenomena, in a heterogeneous and complex media. In order to make the modeling task feasible, many simplifications must be assumed. Hence, different simplified models, such as Michaelis-Menten and Langmuir-based ones, have been used to describe batch processes. However, these simple models have difficulties in predicting fed-batch operations with different feeding policies. To overcome this problem and avoid an increase in the complexity of the model by incorporating other phenomenological terms, a Takagi-Sugeno Fuzzy approach has been proposed, which manages a consortium of different simple models for this process. Pretreated sugar cane bagasse was used as biomass in this case study. The fuzzy rule combines two Michaelis-Menten-based models, each responsible for describing the reaction path for a distinct range of solids concentrations in the reactor. The fuzzy model improved fitting and increased prediction in a validation data set.

Effective Extraction of Lignin from Elephant Grass Using Imidazole and Its Effect on Enzymatic Saccharification To Produce Fermentable Sugars

2017 ◽  
Vol 56 (17) ◽  
pp. 5138-5145 ◽  
Author(s):  
Andréia Toscan ◽  
Ana Rita C. Morais ◽  
Susana M. Paixão ◽  
Luís Alves ◽  
Jürgen Andreaus ◽  
...  
Keyword(s):  
Enzymatic Saccharification ◽  
Fermentable Sugars ◽  
Elephant Grass
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