The quest for alternatives to microbial cellulase mix production: corn stover-produced heterologous multi-cellulases readily deconstruct lignocellulosic biomass into fermentable sugars

2011 ◽  
Vol 86 (5) ◽  
pp. 633-641 ◽  
Author(s):  
Sang-Hyuck Park ◽  
Callista Ransom ◽  
Chuansheng Mei ◽  
Robab Sabzikar ◽  
Chunfang Qi ◽  
...  
Keyword(s):  
Corn Stover ◽  
Lignocellulosic Biomass ◽  
Fermentable Sugars

Densifying Lignocellulosic biomass with alkaline Chemicals (DLC) pretreatment unlocks highly fermentable sugars for bioethanol production from corn stover

2021 ◽  
Author(s):  
Xiangxue Chen ◽  
Xinchuan Yuan ◽  
Sitong Chen ◽  
Jianming Yu ◽  
Rui Zhai ◽  
...  
Keyword(s):  
Corn Stover ◽  
Lignocellulosic Biomass ◽  
Low Cost ◽  
Fermentable Sugars ◽  
Bioethanol Production ◽  
Biomass Logistics

DLC pretreatment, which is simple and of low cost, not only facilitates biomass logistics but also provides a feedstock with high digestibility and high fermentability.

scholarly journals Supercharged Cellulases Show Reduced Non-Productive Binding, But Enhanced Activity, on Pretreated Lignocellulosic Biomass

2021 ◽  
Author(s):  
Bhargava Nemmaru ◽  
Jenna Douglass ◽  
John M Yarbrough ◽  
Antonio De Chellis ◽  
Srivatsan Shankar ◽  
...  
Keyword(s):  
Cell Wall ◽  
Corn Stover ◽  
Lignocellulosic Biomass ◽  
Hydrolytic Activity ◽  
Fine Tuning ◽  
Cellulolytic Enzymes ◽  
Crystalline Cellulose ◽  
Cell Wall Components ◽  
Carbohydrate Binding Modules ◽  
Wall Components

Non-productive adsorption of cellulolytic enzymes to various plant cell wall components, such as lignin and cellulose, necessitates high enzyme loadings to achieve efficient conversion of pretreated lignocellulosic biomass to fermentable sugars. Carbohydrate-binding modules (CBMs), appended to various catalytic domains (CDs), promote lignocellulose deconstruction by increasing targeted substrate-bound CD concentration but often at the cost of increased non-productive enzyme binding. Here, we demonstrate how a computational protein design strategy can be applied to a model endocellulase enzyme (Cel5A) from Thermobifida fusca to allow fine-tuning its CBM surface charge, which led to increased hydrolytic activity towards pretreated lignocellulosic biomass (e.g., corn stover) by up to ~330% versus the wild-type Cel5A control. We established that the mechanistic basis for this improvement arises from reduced non-productive binding of supercharged Cel5A mutants to cell wall components such as crystalline cellulose (up to 1.7-fold) and lignin (up to 1.8-fold). Interestingly, supercharged Cel5A mutants that showed improved activity on various forms of pretreated corn stover showed increased reversible binding to lignin (up to 2.2-fold) while showing no change in overall thermal stability remarkably. In general, negative supercharging led to increase hydrolytic activity towards both pretreated lignocellulosic biomass and crystalline cellulose whereas positive supercharging led to a reduction of hydrolytic activity. Overall, selective supercharging of protein surfaces was shown to be an effective strategy for improving hydrolytic performance of cellulolytic enzymes for saccharification of real-world pretreated lignocellulosic biomass substrates. Future work should address the implications of supercharging cellulases from various families on inter-enzyme interactions and synergism.

scholarly journals Derived high reducing sugar and lignin colloid particles from corn stover

BMC Chemistry ◽  
2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Wei Liu ◽  
Shengnan Zhuo ◽  
Mengying Si ◽  
Mengting Yuan ◽  
Yan Shi
Keyword(s):  
Corn Stover ◽  
Lignocellulosic Biomass ◽  
Alternative Energy ◽  
Reducing Sugar ◽  
Sugar Yield ◽  
Potential Candidate ◽  
Practical Utilization ◽  
Lignin Concentration ◽  
Colloid Particles ◽  
G Ratio

AbstractLignocellulosic biomass is considered as the largest potential candidate to develop alternative energy, such as biofuel, biomaterial. However, the efficient conversion of cellulose and practical utilization of lignin are great challenges for sustainable biorefinery. In this study, high reducing sugar yield and different size of lignin colloid particles (LCPs) were obtained via tetrahydrofuran–water (THF–H2O) pretreatment of corn stover (CS). THF–H2O as a co-solvent, could efficiently dissolve lignin and retain cellulose. After the pretreatment, 640.87 mg/g of reducing sugar was produced, that was 6.66-fold higher than that of the untreated CS. Meanwhile, the pretreatment liquor could form spherical LCPs with different sizes ranged from 202 to 732 nm through self-assembly. We studied the optimal pretreatment condition to simultaneously realize the high reducing sugar yield (588.4 mg/g) and excellent LCPs preparation with average size of 243 nm was under TH22 (THF–H2O pretreatment at 120 °C for 2 h). To further explore the formation of LCPs with different sizes. We studied the lignin structure changes of various conditions, concluded the size of LCPs was related to the lignin concentration and syringyl/guaiacyl (S/G) ratio. As the increase of the lignin concentration and S/G, the sizes of LCPs were increased. G-type lignin was easier to dissolve in the mild pretreatment supernatant, contributing to form smaller LCPs with a good dispersibility. In the severe condition, both of S and G-type lignin were dissolved due to the lignin depolymerization, formed the larger sphere particles. This work provides a novel perspective for the technical design of lignocellulosic biomass conversion.

PRODUCTION OF BIOFUEL FROM WASTE LIGNOCELLULOSIC BIOMASS MATERIALS BASED ON ENERGY SAVING VIEWPOINT

2012 ◽  
Vol 06 ◽  
pp. 715-720
Author(s):  
Maki Takano ◽  
Kazuhiro Hoshino
Keyword(s):  
Lignocellulosic Biomass ◽  
Rice Straw ◽  
Steam Explosion ◽  
Simultaneous Saccharification And Fermentation ◽  
Biofuel Production ◽  
Fermentable Sugars ◽  
Renewable Material ◽  
Suitable Combination ◽  
Biomass Materials ◽  
Simultaneous Saccharification

To develop biofuel production from waste lignocellulosic biomass materials the rice straw was selected one of renewable material and the degradation condition about pretreatment and enzymatic hydrolysis to obtain effectively fermentable sugars was investigated. Rice straw was pretreated by five kinds of methods and then the components ratio of rice straw was examined. First, the steam explosion was selected based on the degradability and the requirement energy. In addition, the best suitable combination of two cellulases to effective and economical hydrolyze was determined from the degradability of these pretreated rice straws. In the simultaneous saccharification and fermentation of the steam explosion rice straw by combining cellulase cocktail and a novel fermenting fungus, 13.2 g/L ethanol was able to product for 96 h.

Evaluation of microwave-assisted pretreatment of lignocellulosic biomass immersed in alkaline glycerol for fermentable sugars production

2015 ◽  
Vol 185 ◽  
pp. 316-323 ◽  
Author(s):  
Ana Belen Diaz ◽  
Marcia Maria de Souza Moretti ◽  
Carolina Bezerra-Bussoli ◽  
Christiane da Costa Carreira Nunes ◽  
Ana Blandino ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Fermentable Sugars ◽  
Microwave Assisted

The influence of the explosive decompression in steam-explosion pretreatment on the enzymatic digestibility of different biomasses

2017 ◽  
Vol 202 ◽  
pp. 269-280 ◽  
Author(s):  
Christoph-M. Seidel ◽  
Thomas Pielhop ◽  
Michael H. Studer ◽  
Philipp Rudolf von Rohr
Keyword(s):  
Corn Stover ◽  
Lignocellulosic Biomass ◽  
Steam Explosion ◽  
Steam Pressure ◽  
Positive Influence ◽  
Herbaceous Plants ◽  
Enzymatic Digestibility ◽  
Maximum Enhancement ◽  
Steam Explosion Pretreatment ◽  
Pretreatment Conditions

For the production of second generation biofuels from lignocellulosic biomass, pretreatment of the biomass feedstock is necessary to overcome its recalcitrance in order to gain fermentable sugars. Due to many reasons, steam-explosion pretreatment is currently the most commonly used pretreatment method for lignocellulosic biomass on a commercial scale [S. Brethauer and M. H. Studer, CHIMIA, 2015, 69, 572–581]. In contrast to others, we showed that the explosive decompression at the end of this pretreatment step can have a positive influence on the enzymatic digestibility of softwood, especially in combination with high enzyme dosages [T. Pielhop, et al., Biotechnology for Biofuels, 2016, 9, 152]. In this study, the influence of the explosive decompression on the enzymatic digestibility of hardwood and herbaceous plants was systematically studied. Beech and corn stover were pretreated under different pretreatment conditions and enzymatically hydrolysed with different enzyme dosages. The maximum enhancement of the digestibility of corn stover was 16.53% after a 2.5 min pretreatment step at 15 barg steam pressure. For beech, a maximum relative enhancement of 58.29% after a 10 min pretreatment step at 15 barg steam pressure could be reached. With this, we show that the explosive decompression can also enhance the enzymatic cellulose digestibility of hardwood and herbaceous plants.

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