Understanding Bacterial Mechanism Could Lead to Better Technologies for Cellulosic Biomass

2008 ◽  
Vol 3 (8) ◽  
pp. 378-378
Keyword(s):  
Cellulosic Biomass

scholarly journals Complete and efficient conversion of plant cell wall hemicellulose into high-value bioproducts by engineered yeast

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Liang Sun ◽  
Jae Won Lee ◽  
Sangdo Yook ◽  
Stephan Lane ◽  
Ziqiao Sun ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Cellulosic Biomass ◽  
Hemicellulose Hydrolysate ◽  
Acetyl Coa ◽  
Engineered Yeast ◽  
Fermentation Inhibitor ◽  
Acid Lactone

AbstractPlant cell wall hydrolysates contain not only sugars but also substantial amounts of acetate, a fermentation inhibitor that hinders bioconversion of lignocellulose. Despite the toxic and non-consumable nature of acetate during glucose metabolism, we demonstrate that acetate can be rapidly co-consumed with xylose by engineered Saccharomyces cerevisiae. The co-consumption leads to a metabolic re-configuration that boosts the synthesis of acetyl-CoA derived bioproducts, including triacetic acid lactone (TAL) and vitamin A, in engineered strains. Notably, by co-feeding xylose and acetate, an enginered strain produces 23.91 g/L TAL with a productivity of 0.29 g/L/h in bioreactor fermentation. This strain also completely converts a hemicellulose hydrolysate of switchgrass into 3.55 g/L TAL. These findings establish a versatile strategy that not only transforms an inhibitor into a valuable substrate but also expands the capacity of acetyl-CoA supply in S. cerevisiae for efficient bioconversion of cellulosic biomass.

scholarly journals Acceleration of cellodextrin phosphorolysis for bioelectricity generation from cellulosic biomass by integrating a synthetic two-enzyme complex into an in vitro synthetic enzymatic biosystem

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Dongdong Meng ◽  
Ranran Wu ◽  
Juan Wang ◽  
Zhiguang Zhu ◽  
Chun You
Keyword(s):  
Reaction Rate ◽  
Specific Interaction ◽  
Renewable Resource ◽  
Cellulosic Biomass ◽  
Initial Reaction ◽  
Enzyme Complex ◽  
Bioelectricity Generation ◽  
Favorable Reaction ◽  
Enzyme Complexes

Abstract Background Cellulosic biomass, the earth’s most abundant renewable resource, can be used as substrates for biomanufacturing biofuels or biochemicals via in vitro synthetic enzymatic biosystems in which the first step is the enzymatic phosphorolysis of cellodextrin to glucose 1-phosphate (G1P) by cellodextrin phosphorylase (CDP). However, almost all the CDPs prefer cellodextrin synthesis to phosphorolysis, resulting in the low reaction rate of cellodextrin phosphorolysis for biomanufacturing. Results To increase the reaction rate of cellodextrin phosphorolysis, synthetic enzyme complexes containing CDP and phosphoglucomutase (PGM) were constructed to convert G1P to glucose 6-phosphate (G6P) rapidly, which is an important intermediate for biomanufacturing. Four self-assembled synthetic enzyme complexes were constructed with different spatial organizations based on the high-affinity and high-specific interaction between cohesins and dockerins from natural cellulosomes. Thus, the CDP–PGM enzyme complex with the highest enhancement of initial reaction rate was integrated into an in vitro synthetic enzymatic biosystem for generating bioelectricity from cellodextrin. The in vitro biosystem containing the best CDP–PGM enzyme complex exhibited a much higher current density (3.35-fold) and power density (2.14-fold) than its counterpart biosystem containing free CDP and PGM mixture. Conclusions Hereby, we first reported bioelectricity generation from cellulosic biomass via in vitro synthetic enzymatic biosystems. This work provided a strategy of how to link non-energetically favorable reaction (cellodextrin phosphorolysis) and energetically favorable reaction (G1P to G6P) together to circumvent unfavorable reaction equilibrium and shed light on improving the reaction efficiency of in vitro synthetic enzymatic biosystems through the construction of synthetic enzyme complexes.

scholarly journals Model Based Biomass System Design of Feedstock Supply Systems for Bioenergy Production

2013 ◽  
Author(s):  
Kara G. Cafferty ◽  
David J. Muth ◽  
Jacob J. Jacobson ◽  
Kenneth M. Bryden
Keyword(s):  
Supply Chain ◽  
Corn Stover ◽  
Cellulosic Ethanol ◽  
Supply System ◽  
Cellulosic Biomass ◽  
Systems Dynamics ◽  
Climate Conditions ◽  
Unit Operations ◽  
Supply Systems

Engineering feedstock supply systems that deliver affordable, high-quality biomass remains a challenge for the emerging bioenergy industry. Cellulosic biomass is geographically distributed and has diverse physical and chemical properties. Because of this feedstock supply systems that deliver cellulosic biomass resources to biorefineries require integration of a broad set of engineered unit operations. These unit operations include harvest and collection, storage, preprocessing, and transportation processes. Design decisions for each feedstock supply system unit operation impact the engineering design and performance of the other system elements. These interdependencies are further complicated by spatial and temporal variances such as climate conditions and biomass characteristics. This paper develops an integrated model that couples a SQL-based data management engine and systems dynamics models to design and evaluate biomass feedstock supply systems. The integrated model, called the Biomass Logistics Model (BLM), includes a suite of databases that provide 1) engineering performance data for hundreds of equipment systems, 2) spatially explicit labor cost datasets, and 3) local tax and regulation data. The BLM analytic engine is built in the systems dynamics software package Powersim™. The BLM is designed to work with thermochemical and biochemical based biofuel conversion platforms and accommodates a range of cellulosic biomass types (i.e., herbaceous residues, short-rotation woody and herbaceous energy crops, woody residues, algae, etc.). The BLM simulates the flow of biomass through the entire supply chain, tracking changes in feedstock characteristics (i.e., moisture content, dry matter, ash content, and dry bulk density) as influenced by the various operations in the supply chain. By accounting for all of the equipment that comes into contact with biomass from the point of harvest to the throat of the conversion facility and the change in characteristics, the BLM evaluates economic performance of the engineered system, as well as determining energy consumption and green house gas performance of the design. This paper presents a BLM case study delivering corn stover to produce cellulosic ethanol. The case study utilizes the BLM to model the performance of several feedstock supply system designs. The case study also explores the impact of temporal variations in climate conditions to test the sensitivity of the engineering designs. Results from the case study show that under certain conditions corn stover can be delivered to the cellulosic ethanol biorefinery for $35/dry ton.

Ionic Liquid 1-Butyl-3-Methylimidazolium Chloride/FeCl3 Pretreatment of Sugarcane Residue for Second Generation Bioethanol Production

2013 ◽  
Vol 275-277 ◽  
pp. 1662-1665 ◽  
Author(s):  
Qiang Li ◽  
Juan Juan Fei ◽  
Xu Ding Gu ◽  
Geng Sheng Ji ◽  
Yang Liu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Enzymatic Hydrolysis ◽  
Low Temperature ◽  
Second Generation ◽  
Reducing Sugars ◽  
Enzymatic Saccharification ◽  
Cellulosic Biomass ◽  
Candida Shehatae ◽  
Second Generation Bioethanol ◽  
Temperature Pretreatment

This study aims to establish a natural cellulosic biomass pretreatment process using ionic liquid (IL) for efficient enzymatic hydrolysis and second generation bioethanol. The IL 1-Butyl-3-methylimidazolium Chloride/FeCl3 ([Bmim]Cl/FeCl3) was selected in view of its low temperature pretreatment ability and the potential of accelerating enzymatic hydrolysis, and it could be recyclable. The yield of reducing sugars from sugarcane residue pretreated with this IL at 80 oC for 1 h reached 46.8% after being enzymatically hydrolyzed for 24 h. Sugarcane residue regenerated were hydrolyzed more easily than that treated with water. The fermentability of the hydrolyzates, obtained after enzymatic saccharification of the regenerated sugarcane residue, was transformed into bioethanol using Candida shehatae. This microbe could absorb glucose and xylose efficiently, and the ethanol production was 0.38 g/g glucose within 30 h fermentation. In conclusion, the metal ionic liquid pretreatment in low temperature shows promise as pretreatment solvent for natural biomass.

scholarly journals Critical Point Drying: An Effective Drying Method for Direct Measurement of the Surface Area of a Pretreated Cellulosic Biomass

Polymers ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 676 ◽  
Author(s):  
Kyu-Young Kang ◽  
Kyung-Ran Hwang ◽  
Ji-Yeon Park ◽  
Joon-Pyo Lee ◽  
Jun-Seok Kim ◽  
...  
Keyword(s):  
Critical Point ◽  
Surface Area ◽  
Direct Measurement ◽  
Cellulosic Biomass ◽  
Drying Method ◽  
Critical Point Drying

Fuel Ethanol from Cellulosic Biomass

Science ◽  
1991 ◽  
Vol 251 (4999) ◽  
pp. 1318-1323 ◽  
Author(s):  
L. R. LYND ◽  
J. H. CUSHMAN ◽  
R. J. NICHOLS ◽  
C. E. WYMAN
Keyword(s):  
Fuel Ethanol ◽  
Cellulosic Biomass

scholarly journals Structure of a Talaromyces pinophilus GH62 arabinofuranosidase in complex with AraDNJ at 1.25 Å resolution

2018 ◽  
Vol 74 (8) ◽  
pp. 490-495 ◽  
Author(s):  
Olga V. Moroz ◽  
Lukasz F. Sobala ◽  
Elena Blagova ◽  
Travis Coyle ◽  
Wei Peng ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Cellulosic Biomass ◽  
Structural Basis ◽  
Side Chain ◽  
Polymeric Substrates ◽  
Hydrolysis Of ◽  
Insight Into ◽  
Positively Charged ◽  
Talaromyces Pinophilus ◽  
Resolution Structure

The enzymatic hydrolysis of complex plant biomass is a major societal goal of the 21st century in order to deliver renewable energy from nonpetroleum and nonfood sources. One of the major problems in many industrial processes, including the production of second-generation biofuels from lignocellulose, is the presence of `hemicelluloses' such as xylans which block access to the cellulosic biomass. Xylans, with a polymeric β-1,4-xylose backbone, are frequently decorated with acetyl, glucuronyl and arabinofuranosyl `side-chain' substituents, all of which need to be removed for complete degradation of the xylan. As such, there is interest in side-chain-cleaving enzymes and their action on polymeric substrates. Here, the 1.25 Å resolution structure of the Talaromyces pinophilus arabinofuranosidase in complex with the inhibitor AraDNJ, which binds with a K d of 24 ± 0.4 µM, is reported. Positively charged iminosugars are generally considered to be potent inhibitors of retaining glycosidases by virtue of their ability to interact with both acid/base and nucleophilic carboxylates. Here, AraDNJ shows good inhibition of an inverting enzyme, allowing further insight into the structural basis for arabinoxylan recognition and degradation.

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