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The use of an underutilized and abundant lignocellulosic feedstock residue, wheat bran, was studied for ethanol production using dilute phosphoric acid pretreatment followed by fermentation using edible fungi Neurospora intermedia . Wheat bran was subjected to dilute acid pretreatment at varying acid concentrations (0.5–3.0% w/v), temperature (150–210 °C), and reaction time (5–20 min). The interaction of multiple factors showed the optimum pretreatment conditions at acid concentration of 1.75% (w/v), at 190 °C for 10 min. The maximum total polysaccharide yield of 0.27 ± 0.01 g/g dry biomass loading, corresponding to 66% of the theoretical maximum was observed. Subsequent fermentation with N. intermedia showed 85% of the theoretical maximum ethanol yield from the untreated bran glucose. The effect of the dilute acid pretreatment on the functional groups of the wheat bran cellulose was determined with 78% reduction in the cellulose crystallinity index. The validation of the dilute phosphoric acid pretreatment in a demo plant is also reported for the first time. Enzymatic hydrolysis of pretreated slurry from the demo plant showed 85% total theoretical yield of polysaccharides. Compared to the untreated bran biomass, an increase of 51% was observed in the ethanol yield following pretreatment, with a total ethanol yield of 95% theoretical maximum. Higher yield of ethanol is also attributed to the xylose fermenting capability of the fungi. [ABSTRACT FROM AUTHOR]

Highlights: [•] Furfural was produced from corn stover by one stage dilute H3PO4 pretreatment process. [•] Maximum furfural yield was obtained at 200°C and 0.75% (v/v) acid dose. [•] Glucose yield was high from solid residues after enzymatic hydrolysis. [•] Ethanol was produced efficiently from glucose by Saccharomyces cerevisiae. [ABSTRACT FROM AUTHOR]

Highlights: [•] We showed that biochar from agricultural residues can remove fermentation inhibitors. [•] We showed a reduced fermentation lag phase when inhibitors were removed. [•] We demonstrated that the biochar can remain in the broth during fermentation. [•] Neither enzyme nor yeast appeared negatively affected by biochar. [ABSTRACT FROM AUTHOR]

• The SPAP removed part of lignin and disrupted the crystalline regions of bamboo. • Glucose yield of SPAP-DS was 89.06 %, which was 4.5 times higher than PAP-DS. • Sulfomethylation contributed to the decrystallize of bamboo cellulose in the subsequent H 3 PO 4 -pretreatment. The sulfomethylation-aided phosphoric acid pretreatment (SPAP) was investigated for bamboo biorefinery. The yield of glucose and xylose were increased from 19.8 % and 13.88 % for H 3 PO 4 -pretreated D. sinicus alone (PAP-DS) to 89.06 % and 72.92 % for SPAP-DS. Ethanol concentration for SPAP-DS was 13.26 g/L, which improved by about 3-folds than PAP-DS. The SPAP-DS exhibited the lower lignin content and cellulose crystallinity, thus resulting in the enzyme accessibility to cellulose increased remarkably. The pre-step of sulfomethylation loosened compact structure of bamboo, which significantly contributed to the decrystallization of cellulose in the following H 3 PO 4 -pretreatment. The study has potential implications in biomass pretreatments, which should target synergistically and simultaneously toward cellulose, hemicellulose, or lignin fraction for obtaining higher bio-based chemical compounds and biofuels. [ABSTRACT FROM AUTHOR]

[Display omitted] • Glucose release rate and viscosity govern ethanol/glycerol ratio disturbance. • The reduced glycerol concentration results from the decreased broth viscosity. • Transcriptomic landscape of cellulase-assisted ethanol production was investigated. In-situ corn fiber conversion enables to greenly convert corn fiber into bioethanol with saving energy and capital expenditure. However, the remaining challenge is to understand how the additive cellulases improve substrate utilization efficiency but reduce the side-product glycerol concentration. Herein, we investigated a comprehensive responses pattern of cellulases-assisted ethanol production on fermentation properties and transcriptomic level. Two determinants, glucose release rate and viscosity, were identified to govern ethanol/glycerol ratio disturbance. The transcriptomic studies revealed three genes in ethanol synthetic and two genes in synthetic glycerol pathway present remarkably up-regulated (up to 4.28-fold) and down-regulated (up to 4.81-fold) under cellulases condition, respectively. Interestingly, 15 upregulated/downregulated genes were commonly obtained in (non-)cellulases and (non-)sodium-polyacrylate transcriptomic landscape, suggesting the reduced glycerol concentration most likely result from the decreased broth viscosity. This obtained knowledge unmask molecular mechanisms of cellulases-assisted ethanol improvement and empower engineers to rationally optimize the biofuel process for higher ethanol concentration. [ABSTRACT FROM AUTHOR]