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[Display omitted] • New study to expand the use of sugarcane bagasse (SCB) in the biorefinery concept. • Minimized cellulase at 15 U/g NaOH-pretreated SCB efficiently released sugars (70.8%). • K. oxytoca KIS004-91T produced D-lactate at 99.9 g/L with 0.97 g/g by fed-batch SSF. • D-lactate yield approached 97% theoretical maximum with 99.5% optical purity. Sugarcane bagasse (SCB) was utilized for efficiently producing optically pure D-(−)-lactate by Klebsiella oxytoca KIS004-91T strain. Cellulase (15 U/g NaOH-treated SCB) sufficiently liberated high sugars with saccharifications of 79.8 % cellulose and 52.5 % hemicellulose. For separated hydrolysis and fermentation, D-(−)-lactate was produced at 53.5 ± 2.1 g/L (0.98 ± 0.01 g/g sugar utilized or 0.71 ± 0.01 g/g total sugars) while D-(−)-lactate at 47.2 ± 1.8 g/L (0.78 ± 0.03 g/g sugar used or 0.69 ± 0.01 g/g total sugars) was obtained under simultaneous saccharification and fermentation (SSF). D-(−)-lactate at 99.9 ± 0.9 g/L (0.97 ± 0.01 g/g sugar utilized or 0.78 ± 0.01 g/g total sugars) was improved via fed-batch SSF. Based on mass balance, raw SCB of 7 kg is required to produce 1 kg D-(−)-lactate. Unlike others, D-(−)-lactate production was performed in low-cost salt medium without requirements of rich nutrients. Costs regarding medium, purification, and waste disposal may be reduced. This unlocks economic capability of SCB bioconversion or agricultural and agro-industrial wastes into high valuable D-(−)-lactate. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sugarcane bagasse fermentation liquid is used as an additional carbon source. • Addition of fermentation liquid enhanced denitrification efficiency of CWs. • Fermentation liquid mitigated N 2 O emissions than sucrose in all operating stage. • Highest TN removal and lowest GWP were obtained at an influent C/N ratio of 3. Sugarcane bagasse was recycled to produce fermentation liquid (FL) as a supplementary carbon source that was added to constructed wetlands (CWs) for regulating influent carbon to nitrogen ratio (C/N), and then being applied to investigate nitrogen transformations and greenhouse gas emissions. Results showed that this FL achieved faster NO 3 −-N removal and lower N 2 O fluxes than sucrose did, and the lowest N 2 O flux (67.6 μg m−2h−1) was achieved when FL was added to CWs in a C/N of 3. In contrast, CH 4 emissions were higher by the FL addition than by the sucrose addition, although the fluxes under both additions were in a lower range of 0.06–0.17 mg m−2h−1. The utilization of FL also induced significant variations in microbial communities and increased the abundance of denitrification genes. Results showed the application of FL from sugarcane bagasse can be an effective strategy for improving nitrogen removal and mitigating N 2 O emissions in CWs. [ABSTRACT FROM AUTHOR]

[Display omitted] • T. sanguinea LSR01 and T. villosa LSR02 produce biofoams from beer bagasse. • Biofoam production has potential in the valorization of brewery waste. • The mechanical stability of biofoams improves as laccase production increases. • Biofoams have residual laccase activity after drying oven process. • Biofoams can be used as green catalysts in biooxidation reactions. White rot fungi are promising organisms for the production of mycelial-based biofoams, providing a sustainable means of valorizing lignocellulosic wastes. This study explores the utilization of two indigenous fungal species, isolated from Argentina and belonging to the genera Trametes , for producing biofoams from brewery waste. The resulting biofoams exhibited an average density of 0.30 g cm−3, a Young's modulus of approximately 1 MPa, and a compressive stress of around 19 MPa. Additionally, the variation of laccase activity throughout the biofoam production process was evaluated. Surprisingly, residual laccase activity was detected in the biofoams following oven drying at temperatures of 60, 80, and 100 °C. This detection highlights the untapped enzymatic potential of the biofoams and positions them as promising green catalysts for various biotechnological applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Increasing sugarcane bagasse loadings led to decreasing carbohydrate solubilization. • Increasing loadings led to increasing unutilized soluble carbohydrate concentration. • Increasing bagasse loadings led to increasing product formation. • Cocultures increase carbohydrate solubilization and utilization. • Monoculture spent broth causes temporary inhibition on solubilization. • Diluting high solids has a positive effect in solubilization and utilization. In Brazil the main feedstock used for ethanol production is sugarcane juice, resulting in large amounts of bagasse. Bagasse has high potential for cellulosic ethanol production, and consolidated bioprocessing (CBP) has potential for lowering costs. However, economic feasibility requires bioprocessing at high solids loadings, entailing engineering and biological challenges. This study aims to document and characterize carbohydrate solubilization and utilization by defined cocultures of Clostridium thermocellum and Thermoanaerobacterium thermosaccharolyticum at increasing loadings of sugarcane bagasse. Results show that fractional carbohydrate solubilization decreases as solids loading increases from 10 g/L to 80 g/L. Cocultures enhance solubilization and carbohydrate utilization compared to monocultures, irrespective of initial solids loading. Rinsing bagasse before fermentation slightly decreases solubilization. Experiments studying inhibitory effects using spent media and dilution of broth show that negative effects are temporary or reversible. These findings highlight the potential of converting sugarcane bagasse via CBP, pointing out performance limitations that must be addressed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Non-treated sugarcane bagasse can be solubilized by Clostridium thermocellum. • Cotreatment led to a 1.8-fold increase in total carbohydrate solubilization. • Thermoanaerobacterium thermosaccharolyticum can withstand cotreatment conditions. • Coculturing and cotreatment increased overall product formation by 2-fold. • The hemicellulose fractional solubilization was higher under cotreatment conditions. Cotreatment, mechanical disruption of lignocellulosic biomass during microbial fermentation, is a potential alternative to thermochemical pretreatment as a means of increasing the accessibility of lignocellulose to biological attack. Successful implementation of cotreatment requires microbes that can withstand milling, while solubilizing and utilizing carbohydrates from lignocellulose. In this context, cotreatment with thermophilic, lignocellulose-fermenting bacteria has been successfully evaluated for a number of lignocellulosic feedstocks. Here, cotreatment was applied to sugarcane bagasse using monocultures of the cellulose-fermenting Clostridium thermocellum and cocultures with the hemicellulose-fermenting Thermoanaerobacterium thermosaccharolyticum. This resulted in 76 % carbohydrate solubilization (a 1.8-fold increase over non-cotreated controls) on 10 g/L solids loading, having greater effect on the hemicellulose fraction. With cotreatment, fermentation by wild-type cultures at low substrate concentrations increased cumulative product formation by 45 % for the monoculture and 32 % for the coculture. These findings highlight the potential of cotreatment for enhancing deconstruction of sugarcane bagasse using thermophilic bacteria. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful translation of steam explosion parameters to pressurised disc refining. • Miscanthus xylan hydrolysis of ∼ 90 % at batch SE-THP and ∼ 80 % at continuous PDR-THP. • Discussion of scale-up issues highlighted. The first comparative pre-treatment study of Miscanthus (Mxg) and sugarcane bagasse (SCB) using steam explosion (SE) and pressurised disc refining (PDR) pretreatment to optimise xylose and xylo -oligosaccharide release is described. The current investigation aimed to 1) Develop optimised batch-wise steam explosion parameters for Mxg and SCB, 2) Scale from static batch steam explosion to dynamic continuous pressurised disc refining, 3) Identify, understand, and circumvent scale-up production hurdles. Optimised SE parameters released 82% (Mxg) and 100% (SCB) of the available xylan. Scaling to PDR, Miscanthus yielded 85% xylan, highlighting how robust scouting assessments for boundary process parameters can result in successful technical transfer. In contrast, SCB technical transfer was not straightforward, with significant differences observed between the two processes, 100% (SE) and 58% (PDR). This report underlines the importance of feedstock-specific pretreatment strategies to underpin process development, scale-up, and optimisation of carbohydrate release from biomass. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful one-pot synthesis of furan-modified lignin from agricultural waste. • Lignin can be successfully modified with furans during the lignin-first approach. • 2D HSQC data reveals the successful attachment of furan molecules with lignin. • The solid residue converted to 5-chloromethyl furfural in a biphasic solvent system. This study investigated a lignin-first approach to produce furan-modified lignin from sugarcane bagasse (SB), rice hull (RH), and sunn hemp biomass (SHB) using 5 methylfurfural (MF) and 5 methul-2-furanmethanol (MFM). The reaction time (5 h) was selected based on the delignification of SB using methanol and Ru/C catalyst which yielded the highest hydroxyl content. Delignification of SB with various MF weight ratios (1:1, 1:2, 1:3, 2:1, and 3:1) revealed that 1:1 and 2:1 ratios produced the highest hydroxyl content (7.7 mmol/g) and bio-oil yield (23.2 % wt% total weight). Further exploration identified that RH and MF at 1:1 ratio and SHB and MF at a 2:1 ratio produced the highest hydroxyl content (13.0 mmol/g) and bio-oil yield (31.6 % wt% tot. weight). This study developed a one-step method to extract and modify lignin with furan compounds simultaneously while opening new avenues for developing value-added products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Liquefaction is linearly correlated to saccharification based on rheological change. • Size reduction of submillimeter particles has no correlation with slurry rheology. • Free water and insoluble solids/components are associated with rheological behavior. • Interrelated particle properties are successfully integrated into two new variables. • Saccharification can be well predicted by two PCA variables with a high R2 of 0.96. This study identified the intrinsic relationships among slurry rheology, particle characteristics, and lignocellulosic liquefaction/saccharification based on correlation analysis and principal component analysis during the hydrolysis of sugarcane bagasse pretreated by deep eutectic solvents (DES) and mechanical milling (MM). The DES-MM pretreated lignocellulosic slurry (20% solids) exhibited high apparent viscosity of 1.4 × 104 Pa·s and shear stress of 929.0 Pa under steady state. Glucose production had a negative linear correlation with slurry viscosity (R2 , 0.69–0.97), whereas its correlation with yield stress (R2 , 0.85–0.98) depended on the particle liquefaction rate. The availability of free water provided a major contribution to improving slurry rheology. However, the size reduction of submillimeter particles and the changes in particle hydrophilicity during liquefaction were not significantly correlated with rheological changes. Various interrelated particle characteristics and rheological changes were integrated into two simple principal variables to predict glucose production with a high R2 of 0.96. [ABSTRACT FROM AUTHOR]

[Display omitted] • Industrially wastewater treated Bagasse was explored to bioenergy production. • Established boosted regression tree Model with Pseudo component analysis. • Pyrolysis and thermodynamic experiments were explored. • Products analysis confirmed the feasibility to produce bioenergy. • Reaction mechanism to identify product descriptions and reaction chemistry. This study explored bagasse's energy potential grown using treated industrial wastewater through various analyses, experimental, kinetic, thermodynamic, and machine learning boosted regression tree methods. Thermogravimetry was employed to determine thermal degradation characteristics, varying the heating rate from 10 to 30 °C/min. The primary pyrolysis products from bagasse are H 2 , CH 4 , H 2 O, CO 2 , and hydrocarbons. Kinetic parameters were estimated using three model-free methods, yielding activation energies of approximately 245.98 kJ mol−1, 247.58 kJ mol−1, and 244.69 kJ mol−1. Thermodynamic parameters demonstrated the feasibility and reactivity of pyrolysis with ΔH ≈ 240.72 kJ mol−1, ΔG ≈ 162.87 kJ mol−1, and ΔS ≈ 165.35 J mol−1 K-1. The distribution of activation energy was analyzed using the multiple distributed activation energy model. Lastly, boosted regression trees predicted thermal degradation successfully, with an R2 of 0.9943. Therefore, bagasse's potential as an eco-friendly alternative to fossil fuels promotes waste utilization and carbon footprint reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrodynamic cavitation showed high performance for acid pretreatment of SCB. • 97 % glucan hydrolysis yield was obtained in HC-assisted FENTON pretreatment. • SSCF with interconnected columns was used to produce ethanol with S. parashehatae. • SSCF fed-batch was interesting to increase the concentration of released sugars. A new alternative for hydrodynamic cavitation-assisted pretreatment of sugarcane bagasse was proposed, along with a simultaneous saccharification and co-fermentation (SSCF) process performed in interconnected columns. Influential variables in the pretreatment were evaluated using a statistical design, indicating that an ozone flow rate of 10 mg min−1 and a pH of 5.10 resulted in 86 % and 72 % glucan and xylan hydrolysis yields, respectively, in the subsequent enzymatic hydrolysis process. Under these optimized conditions, iron sulfate (15 mg L−1) was added to assess Fenton pretreatment, resulting in glucan and xylan hydrolysis yields of 92 % and 71 %, respectively, in a material pretreated for 10 min. In SSCF, ethanol volumetric productivities of 0.33 g L−1 h−1 and of 0.54 g L−1 h−1 were obtained in batch and fed-batch operation modes, achieving 26 g L−1 of ethanol in 48 h in the latter mode. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bagasse was catalyzed to yield HMF and FAL by CTA:BT (170 °C, 0.5 h). • Reduction of HMF and FAL was conducted by SCFD23 cell co-expressing FDH and SsCR. • Bagasse was transformed into furans via a chemobiocatalytical approach in DES-water. • Co-production of DHMF and FOL was conducted from biomass in one-pot two-step way. 2,5-Dihydroxymethylfuran and furfuryl alcohol serve as versatile building-blocks in pharmaceuticals, polymers, and value-added intermediates. To develop an efficient and sustainable method for their production from biomass, a combined approach using deep eutectic solvent Citric acid:Betaine (CTA:BT) for bagasse catalysis and recombinant E. coli SCFD23 for bioreduction of bagasse-derived 5-hydroxymethylfurfural and furfural was devised. Bagasse was effectively transformed into 5-hydroxymethylfurfural (48 mM) and furfural (14 mM) in CTA:BT (8 wt%)-water at 170 °C for 30 min. Bioreduction of 5-hydroxymethylfurfural and furfural by SCFD23 cell co-expressing formate dehydrogenase and NAD(P)H-dependent aldehyde reductase (SsCR) yielded 2,5-dihydroxymethylfuran (90.0 % yield) and furfuryl alcohol (99.0 % yield) in 6 h, using biomass-derived formic acid, xylose and glucose as co-substrates. Molecular docking confirmed the stable binding and reductase activity of SsCR with the biomass-derived 5-hydroxymethylfurfural and furfural. An efficient and eco-friendly chemobiological approach was applied for co-production of 2,5-dihydroxymethylfuran and furfuryl alcohol from biomass in one-pot two-step reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • The MBBR material showed ECmax of 416 g/m3·h at EBRT of 120 s. • The SCB material showed ECmax of 273 g/m3·h at EBRT of 180 s. • SCB accumulated with sulfur can be used as agricultural fertilizer. • The dominant bacteria immobilized on both BTFs were Acidithiobacillus sp. • SCB could be excellent alternative packing material, due to low cost and high EC. This study compared two biotrickling filter packing materials for hydrogen sulfide removal. Inlet H 2 S concentrations and empty-bed retention time were tested on the two biotrickling filters. First reactor (BT1) had immobilized sulfur-oxidizing bacteria on commercial moving-bed media, whereas second reactor (BT2) had sulfur-oxidizing bacteria on sugarcane bagasse. The study found that BT1 performed best at 120 s empty-bed retention time, 422.39 g/m3·h hydrogen sulfide loading rate, resulted in 416 g/m3·h hydrogen sulfide elimination capacity. In contrast, BT2 performed best at 180 s empty-bed retention time, 278.77 g/m3·h hydrogen sulfide loading rate, and 273 g/m3·h elimination capacity was achieved. High-throughput sequencing showed Acidithobacillus spp. dominated the sulfur-oxidizing bacteria consortium. Sugarcane bagasse may receive less hydrogen sulfide loading than moving bed medium under optimal conditions, but its low cost and reasonable removal capacity of hydrogen sulfide -containing industrial gases in a biotrickling filter system make it an excellent alternative packing material. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrothermal combined with mild acid allowed the recovery of xylooligosaccharides. • XOS yield of 67.79% was obtained with 5% gluconic acid at 160 °C for 60 min. • Glucose obtained after enzymatic hydrolysis was used for the production of BC. • BC production with XOS can be integrated for sustainable circular bioprocess. A hydrothermal process is a sustainable approach for biorefinery leading to conversion of lignocellulosic (LC) biomass into value-added products. This study is based on the production of xylooligosaccharides (XOS) from pineapple leaves (PL) waste by using mild acid like gluconic acid (GA). GA, when used as catalyst in hydrothermal process to produce XOS the yield improved. The above process can be integrated with bacterial cellulose (BC) production bioprocess via Komagataeibacter europaeus 14,148 where gluconic acid is produced as by-product. Maximum XOS (2–5 degree of polymerisation) yield of 67.79 % in the liquid fraction was obtained via hydrothermal treatment at 160 °C for 60 min with 5% gluconic acid concentration. It is based on the selective solubilization of hemicellulose fraction. Enzymatic hydrolysis of GA hydrothermally pretreated solid fraction of PL biomass gave 14.5 g/L glucose with 5% solid loading and 10 FPU/gds enzyme loading which was employed for Bacterial cellulose production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Glutamic acid (GA) can selectively hydrolyze hemicellulose in sugarcane bagasse. • GA promoted the enzymatic reaction of cellulase. • Separation of GA and xylo -oligosaccharide (XOS) solution was not required. • The yield of XOS obtained from sugarcane bagasse by GA hydrolysis was 56.42%. • Efficient co-production of XOS and fermentable sugars from sugarcane bagasse. In the production of xylo -oligosaccharides (XOS) by organic acid pretreatment, it is often difficult to isolate organic acids from XOS. Here, an acidic amino acid, glutamic acid (GA), was used to pretreat sugarcane bagasse (SCB) to prepare XOS and fermentable sugars. The effects of GA concentration, hydrolysis temperature, and pretreatment time on the yield and polymerization distribution of XOS were investigated. After hydrolysis by 0.2 M GA at 140 °C for 30 min, the maximum yield of X 2-5 was 53.3%, and the concentrations of xylose and furfural were 1.8 g/L and 0.1 g/L, respectively. Meanwhile, GA increased the pore size and porosity of SCB as well as the number of functional groups of amino acid residues, which improved the enzymatic efficiency and the maximum yield of glucose was 95.3%. Thus, GA pretreatment provides a more economical, environmentally friendly and sustainable method for the co-production of XOS and glucose from SCB. [ABSTRACT FROM AUTHOR]

[Display omitted] • Syringic acid (SA) pretreatment was used to achieve the full utilization of SCB. • 58.7% XOS DP 2–6 was obtained at 180 °C/20 min with 9% SA additive. • Lignin degree of condensation decreased from 0.55 to 0.42 after SA additive. • Glucose yield reached 92.4% at lower enzyme due to the less lignin inhibition. • SA is a catalyst, lignin condensation inhibitor, and antimicrobial. Current strategies for the production of xylooligosaccharides (XOS) from biomass through non–enzymatic catalysis often led to a certain degree of lignin condensation, which severely restrains subsequent enzyme hydrolysis of cellulose. Herein, syringic acid (SA) pretreatment was investigated to coproduce XOS, glucose, and less-condensed lignin from sugarcane bagasse. SA acted as a catalyst and lignin condensation inhibitor during the pretreatment. The highest XOS yield of 58.7% (27.7% xylobiose and 24.7% xylotriose) was obtained at 180 °C − 20 min − 9% SA, and the corresponding xylose/XOS ratio was only 0.42. Compared with the pretreatment at 180 °C − 20 min − 0% SA, the addition of 9% SA increased the glucose yield from 85.7% to 92.4% and decreased the degree of lignin condensation from 0.55 to 0.42. Moreover, 26.7% of SA could be easily recovered. This work presents a pretreatment strategy in which the efficient production of XOS and the suppression of lignin condensation are achieved simultaneously. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lignin (47.1%) and xylan (44.6%) were removed at severity factor LogR 0 = 3.67. • Linear relations with saccharification relation were fitted. • The cellulase digestibility of Betaine:LA-treated SCB was 73.8%. • Comprehensive understanding of Betaine:LA pretreated SCB was explored. Green solvents, especially deep eutectic solvents (DESs), are widely applied to pretreat biomass for enhancing its enzymatic hydrolysis. In this work, lactic acid was selected as the hydrogen-bond-donor to prepare Betaine-base DES (Betaine:LA), The DES was utilized to pretreat sugarcane bagasse (SCB) at 160 ℃ for 80 min (severity factor LogR 0 = 3.67). The influences of Betaine:LA treatment on the chemical composition, crystal and microstructure structure of cellulose, and cellulase digestion were investigated. The results showed that the lignin (47.1%) and xylan (44.6%) were removed, the cellulase digestibility of Betaine:LA-treated SCB was 4.2 times that of the raw material. This improved efficiency was attributed to the enhanced accessibility of cellulose, the weakened surface area of lignin, the declined hydrophobicity, and the decreased crystallinity of cellulose. Several compelling linear correlations were fitted between enzymatic hydrolysis and these alterations of physicochemical features, comprehensively understanding enzymatic saccharification of Betaine:LA-pretreated SCB. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pullulan is an interesting alternative for lignocellulosic biorefineries. • Pullulan application can be expanded if produced in a biorefinery concept. • Modification of pullulan can tune and enhance its properties for specific applications. • There is a growing interest in utilizing pullulan in different industrial sectors. Pullulan is an exopolysaccharide produced by Aureobasidium pullulans , with interesting characteristics which lead to its application in industries such as pharmaceuticals, cosmetics, food, and others. To reduce production costs for industrial applications, cheaper raw materials such as lignocellulosic biomass can be utilized as a carbon and nutrient source for the microbial process. In this study, a comprehensive and critical review was conducted, encompassing the pullulan production process and the key influential variables. The main properties of the biopolymer were presented, and different applications were discussed. Subsequently, the utilization of lignocellulosics for pullulan production within the framework of a biorefinery concept was explored, considering the main published works that deal with materials such as sugarcane bagasse, rice husk, corn straw, and corn cob. Next, the main challenges and future prospects in this research area were highlighted, indicating the key strategies to favor the industrial production of pullulan from lignocellulosic biomasses. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Catalytic co-pyrolysis of sugarcane bagasse with waste plastic was investigated. • Mesoporous faujasite-type zeolite from electric arc furnace slag was prepared. • Hydrocarbon production was greatly enhanced with 74.55% selectivity. • Oxygenate content was considerably decreased with 1.24% selectivity. Abstract This study investigated the catalytic co-pyrolysis of sugarcane bagasse (SCB) and waste high-density polyethylene (HDPE) over faujasite-type zeolite derived from electric arc furnace slag (FAU-EAFS) in a fixed-bed reactor. The effects of reaction temperature, catalyst-to-feedstock ratio, and HDPE-to-SCB ratio on product fractional yields and chemical compositions were discussed. The co-pyrolysis of SCB and HDPE over FAU-EAFS increased the liquid yield and enhanced the quality of bio-oil. The maximum bio-oil (68.56 wt%) and hydrocarbon yield (74.55%) with minimum yield of oxygenated compounds (acid = 0.57% and ester = 0.67%) were achieved under the optimum experimental conditions of catalyst-to-feedstock ratio of 1:6, HDPE-to-SCB ratio of 40:60, and temperature of 500 °C. The oil produced by catalytic co-pyrolysis had higher calorific value than the oil produced by the pyrolysis of SCB alone. [ABSTRACT FROM AUTHOR]

• Up to 13 L H 2 /L-d were obtained with binary hydrolysates of agave bagasse in CSTR. • Binary hydrolysates improved H 2 production compared to individual hydrolysates. • The substrate availability is the limiting factor of H 2 production in TBRs. • The H 2 consumption by homoacetogenesis is lower in TBR than in CSTR. • The type of reactor and hydrolysate were decisive in the cost of H 2 production. Continuous hydrogen (H 2) production from individual (Stonezyme, IH) and binary (Celluclast-Viscozyme, BH) enzymatic hydrolysates of agave bagasse was evaluated in continuous stirred-tank reactors (CSTR) and trickling bed reactors (TBR). The volumetric H 2 production rates (VHPR) in CSTR were 13 and 2.25 L H 2 /L-d with BH and IH, respectively. Meanwhile, VHPR of 5.76 and 2.0 L H 2 /L-d were obtained in the TBR configuration using BH and IH, respectively. Differences on VHPR between reactors could be explained by substrate availability, which is intrinsic to the growth mode of each reactor configuration; while differences of VHPR between hydrolysates were possibly related to the composition of enzymatic hydrolysates. Furthermore, homoacetogenesis was strongly influenced by H 2 and substrate transfer conditions. Considering VHPR, H 2 yields, and costs of hydrolysis, hydrogen production from binary hydrolysates of agave bagasse was identified as the most promising alternative evaluated with scale-up potential for the production of energy biofuels. [ABSTRACT FROM AUTHOR]

Highlights • C. glycerinogenes UG21 was used to degrade glucose and furfural in hydrolysates. • Sugarcane bagasse-based BT production was realized by microbial fermentation. • BT production reached 4.9 g/L. • Co-production of ethanol and BT was achieved. Abstract The aim of this work was to realize 1,2,4-butantriol (BT) production from sugarcane bagasse hydrolysates by microbial fermentation, and obtain co-production of BT and ethanol. Candida glycerinogenes UG21 was utilized to reduce the effect of osmolality resulting from high glucose concentration and furfural in hydrolysates on cell growth of BT-producing strains, and produced 54.1 g/L ethanol from glucose. After ethanol recovering, xylose containing stillage was obtained and used for BT production. 1.3 g/L BT was generated by a BT-producing strain. By the deletion of the crr gene and process optimization, BT titer reached 4.9 g/L. Meanwhile, the efficient utilization of sugarcane bagasse was achieved by a two-stage fermentation for co-production of BT and ethanol. This study provided a novel strategy for BT production from sugarcane bagasse, and demonstrated the potential for making full use of sugarcane bagasse hydrolysates to co-production value-added products. [ABSTRACT FROM AUTHOR]

Highlights • An integrative approach for co-producing XOS and GA was designed. • High XOS yield was obtained by HAc pretreatment of sugarcane bagasse. • 96.3% yield of GA was obtained by low pH fermentation of G. oxydans. • 105 g XOS and 340 g GA were co-produced from 1000 g sugarcane bagasse. Abstract An integrated and green process for co-producing xylooligosaccharides (XOS) and gluconic acid (GA), was developed by utilizing sugarcane bagasse as starting material. In this study, the highest XOS yield of 39.1% obtained from the prehydrolysis was achieved with 10% acetic acid at 150 °C for 45 min. Subsequently, 88.6% conversion of cellulose was achieved in a fed-batch enzymatic hydrolysis using a solid loading of 15%. Results of glucose fermentation suggested that inherent regulatory system of strain Gluconobacter oxydans ATCC 621H boosted GA accumulation without the requirement of pH control, leading to a good 96.3% of GA yield. Great performance of this strain offer an economically feasible option for the large-scale sustainable GA production from biomass. Overall, approximately 105 g XOS and 340 g GA were co-produced from 1 kg of dried sugarcane bagasse as feedstock; this integrated process might be a cost-effective option for the comprehensive utilization of sugarcane bagasse. [ABSTRACT FROM AUTHOR]

Highlights • Deacetylation removed 66% of acetyl groups in corn stover and sugarcane bagasse. • Glucose recovery rate was 92.2% from deacetylated and pretreated stover. • Residual xylose reduced 61.3% by blending a C6 yeast with engineered C5/C6 yeast. Abstract Corn stover and sugarcane bagasse are the most widely available agriculture processing biomass and could serve as feedstocks for production of biofuel. In this study, three different technologies are combined to develop a more efficient conversion process for each of these feedstocks. The three technologies are diluted alkaline deacetylation process, combined thermochemical and mechanical shear pretreatment, and fermentation using a combined inoculum of two commercial Saccharomyces yeast strains. The two yeast strains used were a non-GMO and GMO strain engineered for xylose fermentation. The final ethanol concentrations obtained were 35.7 g/L from deacetylated corn stover and 32.9 g/L from sugarcane bagasse. Blending the two yeast reduced residual xylose content from 1.24 g/L to 0.48 g/L and increased ethanol production by 6.5% compared to solely using the C5/C6 yeast. The optimized yeast blend also lowered the amount of C5/C6 yeast required for inoculation by 80%. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The best pretreatment conditions were 1:5, 170 °C, and 3 h for the HWP. • FS, GQDs, and HPC were produced simultaneously by hydrothermal-carbonization process. • The GQDs mainly derived from the dissolved lignin and polysaccharides in HWP process. • The GQDs had small diameter and exhibited a spherical shape and graphene structure. • The oxygen content and pore properties of HPC were controlled by HWP. Abstract A green and facile approach was proposed to simultaneously produce fermentative sugar (FS), graphene quantum dots (GQDs), and hierarchical porous carbon (HPC) from sugarcane bagasse through the hydrothermal-carbonization process. In this work, the maximum yields of FS were 35.77%, 30.54%, 1.23%, 28.52%, and 41.85% for xylose, mannose, glucose, galactose, and arabinose, respectively. The GQDs, with bright blue fluorescence, had an average diameter at 2.26 nm, and exhibited a well-defined spherical shape and graphene structure. The formation mechanism of GQDs was further investigated, and the GQDs mainly derived from the dissolved lignin and polysaccharides. Moreover, the HPC presented a much higher surface area and controllable oxygen content than non-hydrothermal pretreatment porous carbon, whose unique pore structure was mainly resulted from the dissolution of FS. The green and facile approach provides a novel pathway to produce high value-added materials from sugarcane bagasse, developing a foundation for the preparation of better biomass materials. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Commercial immobilized keratinase removed 86.6–91.1% of colorants in TMWW. • Immobilized keratinase had the potential to replace immobilized oxidoreductase to decolorize TMWW. • KMT-wt immobilized modified bagasse cellulose removed 84.7–90.2% of pigments. • Immobilized KMT-wt had the merit of low-cost compared to commercial immobilized keratinase. • Additional reaction catalyzed the unsaturated bond to destroy the conjugated system of melanoidins. Abstract The aim of this work was to study the ability of commercial immobilized hydrolases in the decolorization of molasses wastewater. Commercial immobilized keratinase obtained the highest decolorization yield (86.6–91.1%) among all of commercial immobilized enzymes tested. Immobilized keratinase had the potential to replace immobilized oxidoreductase to decolorize molasses wastewater. Keratinase from Meiothermus taiwanensis WR-220 (KMT) immobilized on modified bagasse cellulose obtained a decolorization yield of 84.7–90.2%. It removed 60.2–65.6% of colorants and 61.4–69.8% of chemical oxygen demand (COD) for 5 days continuously. Notably, the treatment cost was less than 0.15 dollar per ton. Immobilized KMT-wt had similar performance with commercial immobilized keratinase in bleaching molasses wastewater. Importantly, it was more economic. Finally, the results confirmed that additional reaction catalyzing the unsaturated bonds to destroy the conjugated system by keratinase, weakening the chromogenic group of melanoidins. Accordingly, this work is meaningful to the industrial decolorization of molasses wastewater. [ABSTRACT FROM AUTHOR]

Highlights • Hydrochloric acid washing removed 94.25% of the metal content. • Pretreated sweet sorghum bagasse had an obviously loose porous structure. • Hydrochloric acid washing reduced the varieties of bio-oil compounds. • Pretreatment significantly enhanced the d -allose and ketones contents in bio-oil. Abstract Acid washing is an alternative and promising approach for biomass to produce high-quality bio-oil. The hydrochloric acid washing pretreatment of sweet sorghum bagasse was performed in this study. The effects of acid washing on the ultrastructure of sweet sorghum bagasse were investigated using scanning electron microscope and Fourier transform infrared, and the effects on pyrolysis using thermogravimetric analyzer and a fast pyrolysis device. The results indicated acid treatment obviously changed the surface morphology of the cell walls of sweet sorghum bagasse, effectively removed most metals from sweet sorghum bagasse, and increased the volatiles and bio-oil yields. The results showed that bio-oil produced from pretreated sweet sorghum bagasse contained less components categories, lower contents of phenols, aldehydes, furans and alcohols, while much higher contents of d-allose and ketones than that from the original sample. Hydrochloric acid-washing pretreatment of sweet sorghum bagasse can increase the contents of some high-value chemicals in bio-oil. [ABSTRACT FROM AUTHOR]

Highlights • Sweet sorghum bagasse has much of free sugars after squeezing juice. • Single stage autohydrolysis causes degradation of free sugars. • Two-stage autohydrolysis pretreat bagasse minimizing free sugars degradation. • Two-stage autohydrolysis is effective for sugar recovery from Sweet sorghum bagasse. Abstract Modified autohydrolysis combined with mechanical refining has been suggested to recover free sugars from sweet sorghum bagasse and facilitates enzyme access to cellulose in bagasse for enhancing its conversion to fermentable sugars. The amount of total available sugars in sweet sorghum bagasse was found to be 76.1% and this value was used to evaluate the efficiency of the process suggested. Total sugar recovery was achieved up to 68.1% through the single-stage autohydrolysis at 170 °C for 60 min, followed by mechanical refining and enzymatic hydrolysis; however, the sugar recovery through partial degradation of free sugars induced by high-temperature autohydrolysis was lower than expected. A modified two-stage autohydrolysis was suggested to prevent sugar degradation and the total sugar recovery using this process reached 83.9% of total available sugars in sweet sorghum bagasse. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Detoxified acid hydrolysate from agave bagasse was evaluated for H 2 production. • Activated carbon is a suitable material for acid hydrolysate detoxification. • COD and pH were optimized during dark fermentation by central composite design. • Detoxification enhanced H 2 production in 33% compared to undetoxified hydrolysate. • Fermentation of detoxified hydrolysate promotes changes in metabolic pathways. Abstract The aim of this work was to compare the biohydrogen production potential of undetoxified and detoxified acid hydrolysates from A. tequilana bagasse. Detoxification was carried out with activated carbon at different concentrations and pH values. Results indicated that pH was not a significant variable, while the lowest evaluated concentration of activated carbon (1% p/v) significantly promoted the highest removal of acetic acid (89%) with minimal losses of fermentable sugars. Regarding dark fermentation experiments, central composite designs were used to optimize COD and pH variables for both substrates, undetoxified and detoxified hydrolysates (activated carbon 1% p/v and pH 0.6). At optimal conditions, the detoxified hydrolysate produced 33% more biohydrogen than the undetoxified one. Hydrogen molar yields were 1.71 and 1.23 mol H 2 /mol sugar , respectively. This improvement was correlated to changes in metabolic byproducts, since the detoxified hydrolysate produced only acetic and butyric acids, while lactic acid was detected in the undetoxified hydrolysate. [ABSTRACT FROM AUTHOR]

Highlights • Agave tequilana bagasse was pretreated with 1-ethyl-3-methylimidazolium acetate. • Biomass loading, reaction time and temperature conditions were optimized. • High sugar yield was achieved at milder conditions than those previously reported. • Solid recovery after pretreatment was a key factor for improving sugar yield. • Saccharification was improved by decreasing crystallinity and lignin content. Abstract Sequential 2k factorial and central composite designs were used to optimize Agave tequilana bagasse (ATB) pretreatment by using 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]). Reaction time, temperature and solids loading were the studied factors while sugar yield was the response variable. Results indicated that optimal conditions (119 °C, 142 min) using high solids loading (30%) were achieved at lower temperatures and reaction times than those previously reported in the literature. It was also revealed that solid recovery after pretreatment with [Emim][OAc] is a key factor. The increase in enzymatic digestibility of pretreated ATB was correlated to a decrease in crystallinity and lower lignin content as observed using microscopy techniques and weaken chemical bonds by Fourier transform infrared spectroscopy. Yields of glucose and xylose in the hydrolysate were 41.3, and 13.0 kg per 100 kg of untreated ATB, which are equivalent to glucan and xylan conversions of 75.9% and 82.9%, respectively. [ABSTRACT FROM AUTHOR]

Highlights • Co-pyrolysis kinetics of bagasse and sewage sludge was investigated. • The reliability of model-free result depends on the number of heating rates. • A new proposed approximation to the general temperature factor integral. • Temperature-associated frequency factor was introduced in G-DAEM. • The prediction ability of the G-DAEM was good. Abstract In this work, pyrolysis kinetic evolution of mixture of bagasse and sewage sludge with 10%, 30% and 50% (respect to dry initial weight). In terms of kinetic mechanism, the uncertainty of the activation energy obtained by mode-free method was barely known. We found that increasing number of heating rates made result more reliable, but the modeling process more dependent on redundant experiments with extra data. We adapted a novel general distributed activation energy model (G-DAEM) with 5 pseudocomponents for the analysis of kinetic evolution with proposing a more applicable approximation to the general temperature integral. The G-DAEM was trained by data for 20 K/min, and the predictions were performed on data for 15 K/min and 25 K/min. The predictions were well matched to the experimental data. The G-DAEM enhances modeling efficiency of kinetics and provides a effective pathway for high precise model of complicated co-pyrolysis process. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Glucose and xylose were co-fermented by a co-culture of engineered E. coli and yeast. • Co-fermentation of sugars from sugar cane bagasse slurry at 20% solids was achieved. • Xylose fermentation rate of E. coli in media with glucose was 1.58 ± 0.21 g.L−1.h−1. Abstract Microorganisms ferment xylose at high rate only when glucose concentration in the medium falls below a critical level. Since the specific productivity of product is highest during exponential to early stationary phase of growth, a glucose utilization negative ethanologenic E. coli (strain LW419a) was constructed for high rate of xylose fermentation in combination with Turbo yeast. This co-culture fermented all the released sugars in an acid/enzyme-treated sugar cane bagasse slurry (10% solids) to an ethanol titer of 24.9 ± 0.8 g.L−1 (70% of the theoretical yield) in <30 h. Ethanol titer increased to 48.6 ± 1.04 g.L−1 (yield, 0.45 g.g−1 sugars) at a solids content of 20% and the highest rate of xylose consumption was 1.58 ± 0.21 g.L−1.h−1. This study demonstrates the potential of a co-culture of strain LW419a and yeast to rapidly ferment all the sugars in pretreated biomass slurries to ethanol at their respective highest rates. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Novel GH-10, GH-11 endoxylanases from Kitasatospora were expressed in S. lividans. • The enzyme showed high specific activity, thermostable and broad range pH activity. • High hydrolysis on xylan-based substrates and on extracted xylan from bagasse. • Kitasatospora can produce enzymes capable for xylose and XOS production. Abstract A novel strategy for the low-cost, high-yield co-production of xylose and xylooligosaccharides together with no xylose inhibition was developed using a novel heterologous expression of XYN10Ks_480 endo -1,4-β-xylanase with a ricin-type β-trefoil type of domain and XYN11Ks_480 endo -1,4-β-xylanase with a CBM 2 superfamily from the Kitasatospora sp in an actinomycetes expression system. Xylose is the main building block for hemicellulose xylan. Our findings demonstrated high levels of expression and catalytic activity for XYN10Ks_480 during hydrolysis of the extracted xylan of bagasse, and three types of xylan-based substrates were used to produce xylose and xylooligosaccharides. However, hydrolysis by XYN11Ks_480 produced xylooligosaccharides without xylose formation. This study demonstrated how integrating sodium hypochlorite-extracted xylan and enzymatic hydrolysis could provide an alternative strategy for the generation of XOS from lignocellulosic material. [ABSTRACT FROM AUTHOR]

Graphical abstract Improved production of crude enzyme by mean of mixed substrate of rice straw & orange peels in presence of graphene oxide and subsequent biohydrogen production using sugar cane bagasse hydrolyzate under co-cultivation system following dark fermentation. Highlights • Highly active cellulase is produced in presence of GO under fungal co-culture system. • GO treated crude enzyme shows long thermal and broad range pH stability. • High sugar (70.04 g/L) production is recorded in 14 h at 55 °C. • Sugar hydrolyzate is used for dark fermentative hydrogen production. • Cumulative hydrogen of 2870 ml/L with maximum production rate of 31.66 ml/L/h in 72 h. Abstract Graphene oxide (GO) treated thermostable crude cellulase has been obtained via fungal co-cultivation of strain Cladosporium cladosporioides NS2 and Emericella variecolor NS3 using mix substrate of orange peel and rice straw under solid state fermentation (SSF). Enzyme activity of 60 IU/gds FP, 300 IU/gds EG and 400 IU/gds BGL are recorded in the presence of 1.0% GO in 96 h. This crude enzyme showed 50 °C as optimum incubation temperature, thermally stable at 55 °C for 600 min and stability in the pH range 4.5–8.0. Further, 70.04 g/L of sugar hydrolyzate is obtained from enzymatic conversion of 3.0% alkali pre-treated baggase using GO treated crude cellulase. Finally, 2870 ml/L cumulative biohydrogen production having bacterial biomass ∼2.2 g/L and the complimentary initial pH 7.0 is recorded from sugar hydrolyzate via dark fermentation using co-culture of Clostridium pasteurianum (MTCC116) and a newly isolated Bacillus subtilis PF_1. [ABSTRACT FROM AUTHOR]

Highlights • Solid fermentation of sugarcane bagasse in the absence of supplementation in the medium. • Purification, characterization and application of a new halotolerant and thermostable endoglucanases. • Saccharify different agro-industrial residues of lignocellulosic nature without requiring pretreatment. Abstract A halotolerant endoglucanase with a molecular mass of 39 kDa was obtained from the solid fermentation of sugarcane bagasse by the fungus Botrytis ricini URM 5627 and isolated using only two purification processes: fractionation with ammonium sulphate and size-exclusion chromatography resulting in an activity of 1289.83 U/mL. After the isolation, biochemical characterizations were performed, giving a temperature of 50 °C and optimum pH of 5. The enzyme was stable at 39–60 °C for 60 min and at a pH of 4–6. The enzymatic activity increased in the presence of Na+, Mn2+, Mg2+ and Zn2+ and decreased in the presence of Ca2+, Cu2+, and Fe2+. The endoglucanase revealed a halotolerant profile since its activity increased proportionally to an increase in NaCl concentration. The maximum activity was reached at 2 M NaCl with a 75% increase in activity. The enzyme had a K m of 0.1299 ± 0.0096 mg/mL and a V max of 0.097 ± 0.00121 mol/min/mL. During application in saccharification tests, the enzyme was able to hydrolyse sugarcane bagasse, rice husk, and wheat bran, with the highest production of reducers/fermentable sugars within 24 h of saccharification for wheat bran (137.21 mg/g). Therefore, these properties combined make this isolated enzyme a potential candidate for biotechnological and industrial applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Optimum xylitol yield from bagasse using C. tropicalis on PU foam = 0.65 g/g of xylose. • Significant medium components: yeast extract, MgSO 4 ·7H 2 O, KH 2 PO 4 and (NH 4) 2 SO 4. • Significant process parameters: temperature, pH, agitation and substrate concentration. • Xylitol yield of 0.66 g/g of xylose in ultrasound-assisted fermentation in just 15 h. • Application of sonication resulted in >2-fold enhancement of xylitol productivity. Abstract This study investigates ultrasonic enhancement of xylitol production from sugarcane bagasse using C. tropicalis MTCC 184 immobilized on PU foam. Initial xylitol yield of 0.53 g/g xylose improved to 0.65 g/g of xylose (in 36 h fermentation) after optimization of medium and fermentation parameters. Optimum values of experimental parameters for maximum xylitol were: yeast extract = 5.78 g/L, (NH 4) 2 SO 4 = 3.22 g/L, KH 2 PO 4 = 0.58 g/L, MgSO 4 ·7H 2 O = 0.57 g/L and temperature = 29.3 °C, initial pH = 6.2, agitation rate = 151 rpm and initial xylose concentration = 20.9 g/L. Application of 37 kHz sonication @10% duty cycle during fermentation at optimum conditions resulted in marked intensification of fermentation kinetics. Xylitol yield of 0.66 g/g of xylose has been obtained in ultrasound-assisted fermentation in just 15 h. Fitting of time profiles of substrates and products to kinetic model has highlighted actual physical mechanisms underlying 2-fold faster kinetics induced by sonication. [ABSTRACT FROM AUTHOR]

Highlights • C. glutamicum Δ iolR efficiently converts d -xylose to d -xylonate. • The putative myo -inositol 2-dehydrogenase IolG can catalyze oxidation of d -xylose. • Fed-batch operation enables maximum product yield and high volumetric productivity. • Development of a cost-efficient feedstock based on hydrolyzed sugarcane bagasse. • One-pot sequential hydrolysis and fermentation process for d -xylonate production. Abstract It was found that Corynebacterium glutamicum Δ iolR devoid of the transcriptional regulator IolR accumulates high amounts of d -xylonate when cultivated in the presence of d -xylose. Detailed analyses of constructed deletion mutants revealed that the putative myo -inositol 2-dehydrogenase IolG also acts as d -xylose dehydrogenase and is mainly responsible for d -xylonate oxidation in this organism. Process development for d -xylonate production was initiated by cultivating C. glutamicum Δ iolR on defined d -xylose/ d -glucose mixtures under batch and fed-batch conditions. The resulting yield matched the theoretical maximum of 1 mol mol−1 and high volumetric productivities of up to 4 g L−1 h−1 could be achieved. Subsequently, a novel one-pot sequential hydrolysis and fermentation process based on optimized medium containing hydrolyzed sugarcane bagasse was developed. Cost-efficiency and abundance of second-generation substrates, good performance indicators, and enhanced market access using a non-recombinant strain open the perspective for a commercially viable bioprocess for d -xylonate production in the near future. [ABSTRACT FROM AUTHOR]

The present study compares the optimization using Artificial Neural Networks (ANN) and Adaptive Network-based Fuzzy Inference System (ANFIS) in the sugarcane bagasse delignification process using Alkaline Hydrogen Peroxide (AHP). Two variables were assessed experimentally: temperature (25–45 °C) and hydrogen peroxide concentration (1.5–7.5%(w/v)). The Klason Method was used to measure the amount of insoluble lignin, the High Performance Liquid Chromatography (HPLC) was used to determine the glucose and xylose concentrations and the Fourier Transform Infrared Spectroscopy (FT-IR) was applied to identify oxidized lignin structure in the samples. The analytical results were used for training and testing of ANN and ANFIS models. The statistical quality of the models was significant due to the low values of the errors indices (RMSE) and determination coefficient R 2 between experimental and calculated values. [ABSTRACT FROM AUTHOR]

The directional transformation of bagasse (a typical lignocellulose biomass) to bio-jet fuels was achieved by integrating bio- and chemical catalysis reaction processes. [Display omitted] • Directional jet fuel synthesis was achieved by integrating bio-/chemical process. • Dual catalyst bed synthesis mode improved the selectively of bio-jet fuels. • DES pretreatment promoted enzymatic hydrolysis and fermentation of bagasse. • High jet fuel selectivity of 83.0 % and ABE conversion of 95.3 % were achieved. This work demonstrated that bio-jet fuels can be directionally prepared from bagasse (a typical lignocellulose biomass) by integrating bio- and chemical catalysis reaction processes. This controllable transformation started with the preparation of acetone/butanol/ethanol (ABE) intermediates through the enzymolysis and fermentation of bagasse. Pretreatment of bagasse by deep eutectic solvent (DES) promoted the enzymatic hydrolysis and fermentation because it destroyed the structure of biomass and remove lignin in lignocellulose. Subsequently, the selective catalytic conversion of sugarcane derived ABE broth to jet range fuels was achieved through an integrated process: ABE dehydration to light olefins over the HSAPO-34 catalyst and olefin polymerization to bio-jet fuels over the Ni/HBET catalyst. The dual catalyst bed synthesis mode improved the selectively of bio-jet fuels. High selectivity of jet range fuels (83.0 %) and high conversion of ABE (95.3 %) were obtained by the integrated process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Recalcitrance in sugarcane bagasse is ameliorated by glycerol pretreatment. • Crude glycerol pretreatment boosts pyrolytic saccharification of sugarcane bagasse. • Crude glycerol pretreatment limits the production of aromatic inhibitors to biocatalysts. • Thermogravimetric and kinetic analysis disclose levoglucosan formation mechanisms. • Life cycle assessment suggests that the environmental impacts were less. Saccharification is a pivotal step in the conversion of lignocellulose to biofuels and chemicals. In this study, crude glycerol derived from biodiesel production was used in pretreatment to facilitate efficient and clean pyrolytic saccharification of sugarcane bagasse. Delignification, demineralization, destruction of lignin-carbohydrate complex structure, and cellulose crystallinity improvement in crude glycerol pretreated biomass could enhance levoglucosan producing reactions against competitive reactions, and therefore facilitate a kinetically controlled pyrolysis with apparent activation energy increased by 2-fold. Accordingly, selective levoglucosan production (44.4%) was promoted by 6-fold whilst light oxygenates and lignin monomers were limited to <25% in bio-oil. Owing to the high-efficiency saccharification, life cycle assessment suggested that the environmental impacts of the integrated process were less than those of typical acid pretreatment and petroleum-based processes, especially on the acidification (8-fold less) and global warming potential. This study provides an environmentally benign approach to efficient biorefinery and waste management. [ABSTRACT FROM AUTHOR]

[Display omitted] • Optimizing biochars preparation for Cu(II) adsorption was achieved through RSM. • Heating temperature is the critical pyrolysis parameter affecting Cu(II) removal. • Optimized pineapple biochar has a higher Cu(II) adsorption capacity than activated carbon. • Key adsorption mechanisms are complexations, CEC, and electrostatic attraction. • Optimized biochar displayed high reusability. Many industrial wastewaters contain an appreciable amount of toxic copper (Cu(II)) that needs to be properly treated before discharging into receiving water body. Adsorption can effectively remove Cu(II) with optimized parameters. This study investigates the critical pyrolysis parameters of biochar derived from agricultural waste. Optimized biochar showed maximum Cu(II) adsorption capacity of 60.7, 36.8, and 35.5 mg g−1 by PLB, SBB, and CWB at pyrolysis temperatures of 555 ℃, 559 ℃, 507 ℃, respectively, compared with commercial activated carbon (CAC, 40.8 mg g−1). Surface characterization confirmed surface complexation, electrostatic interaction, and cation exchange capacity as Cu(II) removal mechanisms. The presence of humic acid reduced the Cu(II) removal of both CAC and optimized biochars. Optimized PLB displayed high reusability (87% Cu(II) removal efficiency) after five consecutive cycles using pressure cooker regeneration. With excellent Cu(II) adsorption capacity and reusability, the investigated biochars show high applicability potential to Cu(II)-laden wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful loading of Mg-Al-LDOs onto biochar made from bagasse was achieved. • Pore structure and surface properties of modified biochar (BC-MA) were optimized. • Maximum capacity of tetracycline sorption on BC-MA could be up to 250.6 mg g−1. • Mechanisms engaged in tetracycline removal were clarified. • Excellent sustainable regeneration of BC-MA could be obtained by NaOH washing. Tetracycline (TC) and sugarcane bagasse had both exerted enormous strain on environmental security. In this work, new composite adsorbent designed by impregnating bio-waste bagasse with magnesium–aluminum layered double oxides (BC-MA) was innovatively brought forward for TC removal. Benefiting from the abundant adsorption sites supplied by developed pores structure (0.308 cm3·g−1), enlarged surface area (256.8 m2·g−1) and reinforced functional groups, the maximum adsorption amount of BC-MA for TC reached 250.6 mg g−1. Moreover, BC-MA displayed desirable adsorption capacity in diverse water environments coupled with excellent sustainable regeneration ability. The absorption process of TC by BC-MA was spontaneous and endothermic, and the pivotal rate-limiting stage pertained to intraparticle diffusion. The mechanisms proposed here mainly concerned π-π interactions, pore filling, complexation and hydrogen bonding. These findings suggested that the synthesis of modified biochar from bagasse would offer new opportunities for simultaneous waste resource reuse and water pollution control. [ABSTRACT FROM AUTHOR]

[Display omitted] • An agroindustrial residue transformed into a new type of biosorbent. • From sugarcane bagasse to cationic dialdehyde cellulose (cDAC) by a simple method. • Efficient removal of emerging contaminant from water. • The interaction mechanism is explained by the non-linear Langmuir isotherm model. • Recyclable biosorbent, which can be applied efficiently 4 times. Materials based on cellulose have been widely used as a decontaminant agent of wastewater. However, it can not be found in the literature any application of the cationic dialdehyde cellulose (cDAC) in anionic dye removal. Therefore, this study aims a circular economy concept using sugarcane bagasse to obtain a functionalized cellulose by oxidation and cationization. cDAC was characterized by SEM, FT-IR, oxidation degree, and DSC. Adsorption capacity was evaluated by pH, kinetic, concentration effect, strength ionic tests, and recycling. The kinetic followed Elovich model (R2 = 0.92605 for EBT = 100 mg/L) and non-linear Langmuir model (R2 = 0.94542), which resulted in a maximum adsorption capacity of 563.30 mg/g. The cellulose adsorbent reached an efficient recyclability of 4 cycles. Thus, this work presents a potential material to become a new, clean, low-cost, recyclable, and environmentally friendly alternative for effluent decontamination-containing dyes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Enzymatic hydrolysis design was performed to prepare designer hydrolysates. • Xylose-acetic acid hydrolysates were prepared from hemicellulose hydrolysis. • Sequential hydrothermal-mechanical pretreatment facilitates xylan solubilization. • Xylanase supplemented with acetylxylan esterase doubled acetic acid yields. • The optimal yields of xylose and acetic acid were 92% and 62% from energycane. Xylan accounts for up to 40% of the structural carbohydrates in lignocellulosic feedstocks. Along with xylan, acetic acid in sources of hemicellulose can be recovered and marketed as a commodity chemical. Through vibrant bioprocessing innovations, converting xylose and acetic acid into high-value bioproducts via microbial cultures improves the feasibility of lignocellulosic biorefineries. Enzymatic hydrolysis using xylanase supplemented with acetylxylan esterase (AXE) was applied to prepare xylose-acetic acid enriched hydrolysates from bioenergy sorghum, oilcane, or energycane using sequential hydrothermal-mechanical pretreatment. Various biomass solids contents (15 to 25%, w/v) and xylanase loadings (140 to 280 FXU/g biomass) were tested to maximize xylose and acetic acid titers. The xylose and acetic acid yields were significantly improved by supplementing with AXE. The optimal yields of xylose and acetic acid were 92.29% and 62.26% obtained from hydrolyzing energycane and oilcane at 25% and 15% w/v biomass solids using 280 FXU xylanase/g biomass and AXE, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • This paper reports on a simple highly selective pretreatment process for delignification. • The low-temperature water delignification under 90 °C without discharging black liquor. • Geopolymer showed many acidic sites and with high catalytic activity. • OH– ions released from the geopolymer selectively stripped lignin from the fibre surface. • Low-temperature water-cooking process hindered lignin recondensation. Delignification pretreatment is the main source of high cost and high pollution in biomass processing. This paper reports on a simple cheap geopolymers-based highly selective and efficient pretreatment process for delignification under low-temperature water-cooking without discharging black liquor. The geopolymer with a SiO 2 /Al 2 O 3 ratio of 4.4 showed the largest number of acidic sites and highest catalytic activity. Under mild reaction conditions (m Geopolymer /m Fiber = 1/4, 90 min and 90 °C), the delignification rates of woody (eucalyptus) and herbaceous (bagasse) biomass increased by up to 38.90% and 62.20%, respectively. Moreover, the low-alkali black liquor produced by the new water delignification process facilitates subsequent water treatment, eliminating the need for alkali recovery. This study confirms the immense application prospects of geopolymers for the highly selective delignification of most biomass fibre. This study will develop a low-temperature water-cooking process for the delignification of papermaking or biomass processing without wastewater discharge. [ABSTRACT FROM AUTHOR]

[Display omitted] • Feasibility of Sugarcane bagasse (SCB) as potential feedstock for catalytic HTL. • HTL derived biocrude can be served as alternative to fossil fuels. • Ru/C resulted in higher bio-oil (28 %) and energy recovery (120.6 %) during HTL. • The bioprocess (HTL-AF) showed 201 mL/g of bio-H 2 with 64 % carbon conversion. • The study supports zero-waste and carbon neutral efficient bio-refinery processes. The study focuses on the effective conversion of sugarcane bagasse (SCB) by catalytic deoxygenation using various alkali and metal-based catalysts under N 2 pressure employing water as solvent. The specific influence of catalyst over bio-crude yields (bio-oil and aqueous fraction) including energy recovery ratio was explored. The optimum catalytic condition (Ru/C) resulted in ∼ 70% of bio-crude and 28% of bio-oil with an improved HHV (31.6 MJ/kg) having 11.6% of aliphatic/aromatic hydrocarbons (C 10 –C 20) which can be further upgraded to drop-in fuels. The biocrude composed of 44% of aqueous soluble organic fraction (HTL-AF). Further, the carbon-rich HTL-AF was valorized through acidogenic fermentation to yield biohydrogen (Bio-H 2). The maximum bio-H 2 production of 201 mL/g of TOC conversion (K 2 CO 3 catalyst) was observed with 7.7 g/L of VFA. The SCB was valorized in a biorefinery design with the production of fuels and chemical intermediates in a circular chemistry approach. [ABSTRACT FROM AUTHOR]

Bioproduction of generally recognized as safe (GRAS) products starting with low-cost raw materials has become significant in the biorefinery concept. Thus, the solid-state fermentation (SSF) of agro-industrial residues using GRAS strains appears as alternative to obtain aroma compounds. Here, the SSF of the mixture sugarcane bagasse/sugar beet molasses was used for producing a mixture of value-added fruit-like compounds. The study aimed to enhance the production and ester selectivity evaluating three operational strategies at three scales (0.5, 4.5 and 22 L) using non-sterilized residues. While the average total volatile production was 120 mg Vol per gram of dry substrate (g −1 ITS ), fed-batch operation promoted the highest increases in the ester content up to 57 mg Est  g −1 ITS , an 88 and 59% more than in the static-batch and intermittent mixing modes respectively. Alternative operational strategies have compensated the scale-up adverse effects in the bioproduction, moving towards a sustainable large-scale application in a circular economy scheme. [ABSTRACT FROM AUTHOR]

The production of tequila in Mexico generates a large amount of agave bagasse per year. However, this biomass can be considered as a potential source for biofuel production. In this study, it is described how the hydrothermal pretreatment was scaled in a bench scale, considering the severity index as a strategy. The best condition was at 180 °C in isothermal regime for 20 min with 65.87% of cellulose content and high concentration of xylooligosaccharides (15.31 g/L). This condition was scaled up (using severity factor: [log R 0 ] = 4.11), in order to obtain a rich pretreated solid in cellulose to perform the enzymatic hydrolysis, obtaining saccharification yields of 98.5 and 99.5% at high-solids loading (10 and 15%, respectively). The pre-saccharification and fermentation strategy was used in the bioethanol production at 10 and 15% of total pretreated solids, obtaining 38.39 and 55.02 g/L of ethanol concentration, corresponding to 90.84% and 87.56% of ethanol yield, respectively. [ABSTRACT FROM AUTHOR]

Itaconic acid has economic potential as a commodity biochemical for the sugar industry, but its production is limited due to high production costs. Using cheaper and alternative lignocellulosic feedstocks together with achieving higher product titres have been identified as potential strategies for viable IA production. Consequently the use of sugarcane bagasse and trash for the production of itaconic acid (IA) and electricity have been investigated for an integrated biorefinery, where the production facility is annexed to an existing sugar mill and new combined heat and power (CHP) plant. Three IA biorefinery scenarios were designed and simulated in Aspen Plus®. Subsequent economic analyses indicated that cheaper feedstocks reduced the IA production cost from 1565.5 US$/t for glucose to 616.5 US$/t, but coal supplementation was required to sufficiently lower the production cost to 604.3 US$/t for a competitive IA selling price of 1740 US$/t, compared to the market price of 1800 US$/t. [ABSTRACT FROM AUTHOR]

A shrinking-layer model by modification of classical shrinking-core model was developed based on cell wall multi-layered structure for delignification of sugarcane bagasse with sulfuric acid (SA) catalyzed atmospheric acetic acid (AA) fractionation. The general model for overall rate of delignification was obtained and further employed to evaluate the mass transfer effects on delignification. It was found that the external diffusion could be neglected under the studied fractionation conditions, while the internal diffusion appeared to play an important role. The effective diffusion coefficient for lignin within the biomass was estimated as 6.7 × 10 −14 –1.6 × 10 −12  m 2 /s depending on temperature, solid content in the system and molecular weight of lignin. However, surface reaction also seems to be a limiting step to the overall rate of delignification. At the early stage of delignification, both internal diffusion and reaction were controlling steps, while at the late stage reaction seems to be the controlling step. [ABSTRACT FROM AUTHOR]

In this study, liquid hot water pretreatment was combined with disk milling for pretreatment of sugarcane bagasse. Sugarcane bagasse was pretreated using liquid hot water (LHW) at 140–180 °C for 10 min (20% w/w solids content) and then disk milled. Disk milling improved glucose release 41–177% and ethanol production from glucose/xylose cofermentation by 80% compared to only using LHW pretreatment. The highest ethanol conversion efficiency achieved was 94%, which was observed when bagasse was treated at 180 °C with LHW and disk milled. However, a small amount of residual xylose (3 g/L) was indicative that further improvement could be achieved to increase ethanol production. [ABSTRACT FROM AUTHOR]

A process of isobutanol production from sugarcane bagasse hydrolysates in Enterobacter aerogenes was developed here with a pervaporation-integrated procedure. Isobutanol pathway was overexpressed in a mutant strain with eliminated byproduct-forming enzymes (LdhA, BudA, and PflB). A glucose-and-xylose–coconsuming ptsG mutant was constructed for effective utilization of lignocellulosic biomass. Toxic effects of isobutanol were alleviated by in situ recovery via a pervaporation procedure. Compared to single-batch fermentation, cell growth and isobutanol titer were improved by 60% and 100%, respectively, in the pervaporation-integrated fermentation process. A lab-made cross-linked polydimethylsiloxane membrane was cast on polyvinylidene fluoride and used in the pervaporation process. The membrane-penetrating condensate contained 55–226 g m −2  h −1 isobutanol with 6–25 g L −1 ethanol after separation. This study offers improved fermentative production of isobutanol from lignocellulosic biomass with a pervaporation procedure. [ABSTRACT FROM AUTHOR]