Levoglucosan Production by Fast Pyrolysis of Biomass After Dilute Acid Pretreatment

Abstract Background During the dilute acid pretreatment process, the resulting pseudo-lignin and lignin droplets deposited on the surface of lignocellulose and inhibit the enzymatic digestibility of cellulose in lignocellulose. However, how these lignins interact with cellulase enzymes and then affect enzymatic hydrolysis is still unknown. In this work, different fractions of surface lignin (SL) obtained from dilute acid-pretreated bamboo residues (DAP-BR) were extracted by various organic reagents and the residual lignin in extracted DAP-BR was obtained by the milled wood lignin (MWL) method. All of the lignin fractions obtained from DAP-BR were used to investigate the mechanism for interaction between lignin and cellulase using surface plasmon resonance (SPR) technology to understand how they affect enzymatic hydrolysis Results The results showed that removing surface lignin significantly decreased the yield for enzymatic hydrolysis DAP-BR from 36.5% to 18.6%. The addition of MWL samples to Avicel inhibited its enzymatic hydrolysis, while different SL samples showed slight increases in enzymatic digestibility. Due to the higher molecular weight and hydrophobicity of MWL samples versus SL samples, a stronger affinity for MWL (KD = 6.8–24.7 nM) was found versus that of SL (KD = 39.4–52.6 nM) by SPR analysis. The affinity constants of all tested lignins exhibited good correlations (r > 0.6) with the effects on enzymatic digestibility of extracted DAP-BR and Avicel. Conclusions This work revealed that the surface lignin on DAP-BR is necessary for maintaining enzyme digestibility levels, and its removal has a negative impact on substrate digestibility.

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Dilute acid pretreatment of rye straw and bermudagrass for ethanol production

Bioresource Technology ◽

10.1016/j.biortech.2004.12.022 ◽

2005 ◽

Vol 96 (14) ◽

pp. 1599-1606 ◽

Cited By ~ 291

Author(s):

Y SUN ◽

J CHENG

Keyword(s):

Ethanol Production ◽

Dilute Acid Pretreatment ◽

Dilute Acid ◽

Acid Pretreatment ◽

Rye Straw

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Structural Reorganization of Noncellulosic Polymers Observed In Situ during Dilute Acid Pretreatment by Small-Angle Neutron Scattering

ACS Sustainable Chemistry & Engineering ◽

10.1021/acssuschemeng.1c06276 ◽

2021 ◽

Author(s):

Zhi Yang ◽

Marcus B. Foston ◽

Hugh O’Neill ◽

Volker S. Urban ◽

Arthur Ragauskas ◽

...

Keyword(s):

Neutron Scattering ◽

Small Angle ◽

Small Angle Neutron Scattering ◽

Dilute Acid Pretreatment ◽

Dilute Acid ◽

Acid Pretreatment ◽

Structural Reorganization

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A Process Study of Lactic Acid Production from Phragmites australis Straw by a Thermophilic Bacillus coagulans Strain under Non-Sterilized Conditions

Processes ◽

10.3390/pr6100175 ◽

2018 ◽

Vol 6 (10) ◽

pp. 175 ◽

Cited By ~ 3

Author(s):

Yuming Zhang ◽

Mengran Li ◽

Tian Nie ◽

Zhihua Ni

Keyword(s):

Lactic Acid ◽

Phragmites Australis ◽

Lactic Acid Production ◽

Scale Up ◽

Bacillus Coagulans ◽

Dilute Acid Pretreatment ◽

Integrated Process ◽

Dilute Acid ◽

Acid Pretreatment ◽

Process Study

Phragmites australis straw (PAS) is an abundant and renewable wetland lignocellulose. Bacillus coagulans IPE22 is a robust thermophilic strain with pentose-utilizing capability and excellent resistance to growth inhibitors. This work is focused on the process study of lactic acid (LA) production from P. australis lignocellulose which has not been attempted previously. By virtue of thermophilic feature of strain IPE22, two fermentation processes (i.e., separated process and integrated process), were developed and compared under non-sterilized conditions. The integrated process combined dilute-acid pretreatment, hemicellulosic hydrolysates fermentation, and cellulose utilization. Sugars derived from hemicellulosic hydrolysates and cellulose enzymatic hydrolysis were efficiently fermented to LA in a single vessel. Using the integrated process, 41.06 g LA was produced from 100 g dry PAS. The established integrated process results in great savings in terms of time and labor, and the fermentation process under non-sterilized conditions is easy to scale up for economical production of lactic acid from PAS.

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