Weak-Acid Sites Catalyze the Hydrolysis of Crystalline Cellulose to Glucose in Water: Importance of Post-Synthetic Functionalization of the Carbon Surface

A bioethanol by-product, dried distiller’s grains with solubles (DDGS) contains high levels of cellulose and starch. We hypothesized that combinations of solid-state fermentation (SSF) and digestion by black soldier fly larvae (BSFL) (Hermetia illucens) could increase the recovery of glucose from this by-product by concentrating and loosening the cellulose matrix through their activities. DDGS was individually fermented with Aspergillus niger, Aspergillus fumigatus, Trichoderma koningii, Phanerochaete chrysosporium, or Lactobacillus plantarum. The fermented DDGS was fed to BSFL, and glucose recoveries from spent feeds were conducted. SSF increases lipid and protein contents, supporting BSFL growth, and weakens the cellulosic matrix. BSFL use nutrients in SSF–DDGS, further concentrating and weakening the cellulose, i.e., DDGS is halved without changing the cellulose contents. For example, Lactobacillus plantarum SSF with BSFL culture concentrates the cellulose content from 9.7% to 26.5% of spent feed. Glucose recovery was determined using three sequential processes (free glucose determination, weak-acid hydrolysis of amorphous cellulose, and enzymatic hydrolysis of micronized crystalline cellulose). Total glucose obtained from 100 g of DDGS increased from 4.8 to 10.7 g. These results show that the combinations of SSF and BSFL could provide additional fermentable sugars (and insect biomass) from bioethanol by-products, suggesting a high productivity from the same feedstock.

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Deep Eutectic Solvents with Multiple Weak Acid Sites for Highly Efficient, Reversible and Selective Absorption of Ammonia

Separation and Purification Technology ◽

10.1016/j.seppur.2021.118791 ◽

2021 ◽

pp. 118791

Author(s):

Ning-Ning Cheng ◽

Zi-Liang Li ◽

Hong-Chao Lan ◽

Wen-Long Xu ◽

Wen-Jing Jiang ◽

...

Keyword(s):

Deep Eutectic Solvents ◽

Acid Sites ◽

Weak Acid ◽

Selective Absorption ◽

Highly Efficient

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Conditions of hydrolysis with a specific pair of endo- and exo-cellulases

10.32920/ryerson.14652435.v1 ◽

2021 ◽

Author(s):

Yoshiki Kitano

Keyword(s):

Synergistic Effect ◽

Crystalline Cellulose ◽

Carbohydrate Binding ◽

Amorphous Cellulose ◽

Potential Synergy ◽

Hydrolysis Of Cellulose ◽

Potential Alternative ◽

Specific Pair ◽

Hydrolysis Of ◽

Increased Activity

Enzymatic hydrolysis of cellulose is a technology involved in the production of bioethanol, a potential alternative renewable energy. Many cellulases with endo- and exo- type of activity are known to hydrolyze cellulose synergistically. In this thesis, potential synergy between an endo-cellulase, Cel5B, with and without a carbohydrate- binding module (CBM6), and a new exo-cellulase, CBH1, from Trichoderma harzianum FP108 were examined during the hydrolysis of semi- crystalline cellulose (Avicel). Since CBM6 is recognized as having a high affinity for amorphous cellulose, it was hypothesized that this affinity could enhance the synergistic effect between the endo- and exo-cellulases by focusing the action to Cel5B+CBM6 on the amorphous regions of the Avicel substrate. The increased activity of Cel5B+CBM6 over Cel5B alone was confirmed. However, in contrast to our expectations, a synergistic effect was not observed between either endo- and exo-cellulase pairs. From the obtained hydrolysis yield, it was inferred that Cel5B+CBM6 may have exo-type activity that caused a competitive interaction with the exo-cellulase, which resulted in no synergy.

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Effect of Subsequent Dilute Acid and Enzymatic Hydrolysis on Reducing Sugar Production from Sugarcane Bagasse and Spent Citronella Biomass

Journal of Energy ◽

10.1155/2016/8506214 ◽

2016 ◽

Vol 2016 ◽

pp. 1-12 ◽

Cited By ~ 20

Author(s):

Robinson Timung ◽

Narendra Naik Deshavath ◽

Vaibhav V. Goud ◽

Venkata V. Dasu

Keyword(s):

Enzymatic Hydrolysis ◽

Sugarcane Bagasse ◽

Crystallinity Index ◽

Sem Analysis ◽

Reducing Sugar ◽

Dilute Acid Pretreatment ◽

Crystalline Cellulose ◽

Dilute Acid ◽

Acid Pretreatment ◽

Hydrolysis Of

This work was aimed at investigating the effect of process parameters on dilute acid pretreatment and enzymatic hydrolysis of spent citronella biomass (after citronella oil extraction) and sugarcane bagasse on total reducing sugar (TRS) yield. In acid pretreatment, the parameters studied were acid concentration, temperature, and time. At the optimized condition (0.1 M H2SO4, 120°C, and 120 min), maximum TRS obtained was 452.27 mg·g−1and 487.50 mg·g−1for bagasse and citronella, respectively. Enzymatic hydrolysis of the pretreated biomass usingTrichoderma reesei26291 showed maximum TRS yield of 226.99 mg·g−1for citronella and 282.85 mg·g−1for bagasse at 10 FPU, 50°C, and 48 hr. The maximum crystallinity index (CI) of bagasse and citronella after acid pretreatment obtained from X-ray diffraction analysis was 64.41% and 56.18%, respectively. Decreased CI after enzymatic hydrolysis process to 37.28% and 34.16% for bagasse and citronella, respectively, revealed effective conversion of crystalline cellulose to glucose. SEM analysis of the untreated and treated biomass revealed significant hydrolysis of holocellulose and disruption of lignin.

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THE INTERRELATION OF THE SURVIVING HEART AND PANCREAS OF THE DOG IN SUGAR METABOLISM

Journal of Experimental Medicine ◽

10.1084/jem.26.5.721 ◽

1917 ◽

Vol 26 (5) ◽

pp. 721-744 ◽

Cited By ~ 11

Author(s):

Admont H. Clark

Keyword(s):

Optical Rotation ◽

Reducing Power ◽

Sugar Metabolism ◽

Weak Acid ◽

Perfused Pancreas ◽

Melting Points ◽

Optical Rotations ◽

Normal Utilization ◽

Hydrolysis Of ◽

Reducing Properties

When the pancreas of a dog is perfused aseptically with a Locke's solution containing dextrose in physiological concentrations, the optical rotation of the perfusate is diminished, but its reducing power is unaltered. This change also occurs if dextrose is added to a sugarfree pancreatic perfusate and the mixture incubated. These perfusates yield osazones with lower melting points than glucosazone, but when the perfusates are hydrolyzed with weak acid their optical, rotations and the melting points of their osazones are increased. These changes do not occur with levulose, or with an extract of the pancreas and dextrose. When the heart, spleen, or kidneys are perfused with dextrose solutions hydrolysis of the perfusates does not increase their optical rotation or power of reduction. When a pancreatic perfusate containing dextrose is circulated through a living heart not only do the above changes take place but, in addition, the reducing properties of the perfusate are altered. Hydrolysis of such a perfusate increases its reducing power, its optical rotation, and the melting point of its osazone. A heart does not cause this effect either alone or when perfused together with the spleen or kidneys. Levulose perfused through the heart and pancreas is unchanged. These phenomena are believed to be due to an enzyme or enzymes obtained from the perfused pancreas. The changes in optical rotation, in reduction, and in the osazones are accounted for by different degrees of dextrose condensation. While the living heart can destroy both dextrose and levulose to some extent, the experimental results suggest that the enzyme or enzymes derived from the perfused pancreas have a specific action on dextrose and are responsible for certain essential steps by which dextrose is prepared for normal utilization.

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