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• A metaproteomics-based comparison of microbial degradation from ASP to AB was conducted. • Upgrading from ASP to AB increased lignocellulose degradation rates by 18.49-46.52%. • The upgrade from ASP to AB improved diversity of CAZyme-producing microbes. • AB but not ASP can produce the key enzyme for acetate conversion. • AB was superior to ASP for compost decomposition with higher cellulose. Composting presents a viable management solution for lignocellulose-rich municipal solid waste. However, our understanding about the microbial metabolic mechanisms involved in the biodegradation of lignocellulose, particularly in industrial-scale composting plants, remains limited. This study employed metaproteomics to compare the impact of upgrading from aerated static pile (ASP) to agitated bed (AB) systems on physicochemical parameters, lignocellulose biodegradation, and microbial metabolic pathways during large-scale biowaste composting process, marking the first investigation of its kind. The degradation rates of lignocellulose including cellulose, hemicellulose, and lignin were significantly higher in AB (8.21%-32.54%, 10.21%-39.41%, and 6.21%-26.78%) than those (5.72%-23.15%, 7.01%-33.26%, and 4.79%-19.76%) in ASP at three thermal stages, respectively. The AB system in comparison to ASP increased the carbohydrate-active enzymes (CAZymes) abundance and production of the three essential enzymes required for lignocellulose decomposition involving a mixture of bacteria and fungi (i.e., Actinobacteria, Bacilli, Sordariomycetes and Eurotiomycetes). Conversely, ASP primarily produced exoglucanase and β-glucosidase via fungi (i.e., Ascomycota). Moreover, AB effectively mitigated microbial stress caused by acetic acid accumulation by regulating the key enzymes involved in acetate conversion, including acetyl-coenzyme A synthetase and acetate kinase. Overall, the AB upgraded from ASP facilitated the lignocellulose degradation and fostered more diverse functional microbial communities in large-scale composting. Our findings offer a valuable scientific basis to guide the engineering feasibility and environmental sustainability for large-scale industrial composting plants for treating lignocellulose-rich waste. These findings have important implications for establishing green sustainable development models (e.g., a circular economy based on material recovery) and for achieving sustainable development goals. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Inoculation of thermophilic bacterial consortia promoted the compost efficiency. • P V , n/P III , n values revealed the humification degree in different treatments. • Core microbes drove the variations in compost temperature, TOC, TN, and HAC. • Microbial community functions were closely related to compost quality. The objective of this study was to investigate the potential effects of thermophilic bacterial consortia on compost efficiency and quality. The application of bacterial consortia resulted in an earlier onset of the thermophilic period (THP), an increased upper temperature limit, and an extended duration of the THP by 3–5 days compared to the control group (CK). Microbial inoculation significantly improved the efficiency of organic matter degradation, as well as the content of water-soluble nitrogen (WSN) and humic acid-carbon (HAC). In the case of consortium Ⅱ inoculation (T2), the activities of cellobiohydrolase, β-glucosidase, and protease were increased by 81.81 %, 70.13 %, and 74.09 % at the THP respectively compared to CK. During the maturation stage, T2 also exhibited the highest P V , n/P III , n value (1.33) and HAC content (39.53 mg·g−1), indicating that inoculation of consortium Ⅱ effectively promoted substrate maturity and product quality. Moreover, this inoculation effectively optimized the bacterial communities, particularly the growth of Planococcus, Chelatococcus, and Chelativorans during the composting, which were involved in carbon and nitrogen conversion or HAC synthesis. Carbohydrate and amino acid metabolism, and membrane transport were predominant in the consortia-inoculated samples, with an increased gene abundance, suggesting that inoculation contributed to promoting the biodegradation of lignocellulose and the exchange of favorable factors. In conclusion, this study demonstrates that inoculating thermophilic bacterial consortia has a positive impact on enhancing the resource utilization efficiency of agricultural waste and improving the quality of compost products. [ABSTRACT FROM AUTHOR]

Lignocellulose is an important component of domestic biodegradable waste (DBW), and its complex structure makes it an obstacle in the biological treatment of DBW. Here, we identify black soldier fly larvae (Hermetia illucens L., BSFL) as a bioreactor for lignocellulose degradation in DBW based on their ability to effectively recruit lignocellulose-degrading bacteria. This study mainly examined the lignocellulose degradation, dynamic succession of the microbial community, gene expression of carbohydrate-active enzymes (CAZymes), and co-occurrence network analysis. Investigation of lignocellulose degradation by BSFL within 14 days indicated that the lignocellulose biodegradation rate in the larvae treatment (LT, 26.5%) group was higher than in natural composting (NC, 4.06%). In order to gain a more comprehensive understanding of microbiota, we conducted metagenomic sequencing of larvae intestines (LI), along with the LT and NC. The relative abundance of lignocellulose-degrading bacteria and CAZymes genes in LT and LI were higher than those in NC based on metagenomics sequencing. Importantly, genes coding cellulase and hemicellulase in LI were 3.36- and 2.79-fold higher, respectively, than that in LT, while the ligninase genes in LT were 1.82-fold higher than in LI. A co-occurrence network analysis identified Enterocluster and Luteimonas as keystone taxa in larvae intestines and residues, respectively, with a synergistic relationship to lignocellulose-degrading bacteria. The mechanism of recruiting functional bacteria through the larvae intestines promoted lignocellulose degradation in DBW, improving the efficiency of BSFL biotechnology and resource regeneration. [Display omitted] • BSFL recruited lignocellulose degrading functional bacteria in gut-residue system. • BSFL enriched with functional bacteria improved lignocellulose degradation by 526%. • Corynebacterium and Brevibacterium recruited mainly in residues to degrade lignin. • Dysgonomonas, Prevotella, and Miniimonas recruited in gut to degrade celluloses. • Enterocluster and Luteimonas as keystone taxa in BSFL intestines and residues. [ABSTRACT FROM AUTHOR]

The recently identified lytic polysaccharide monooxygenases (LPMOs) are important auxiliary proteins which contribute to lignocellulose biodegradation by oxidatively cleaving the glycosidic bonds in cellulose and other polysaccharides. The vast differences in terms of substrate specificity and regioselectivity within LPMOs provide us new possibilities to find promising candidates for the use in enzyme cocktails in biorefinery applications. In this study, a highly xyloglucan active family AA9 lytic polysaccharide monooxygenase Ep LPMO9A was identified from Eupenicillium parvum 4-14. Ep LPMO9A exhibited a mixed C1/C4 oxidative cleavage activity on cellulose and xyloglucan with a broad range of pH stability and good thermal stability at 40 °C. It showed a higher boosting effect on the enzymatic saccharification of complex lignocellulosic substrates associated with xyloglucan than on the lignocellulosic substrates without xyloglucan particularly in low commercial cellulase dosage cases. The oxidative cleavage of xyloglucan by Ep LPMO9A may facilitate to open up the sterical hindrance of cellulose by xyloglucan and thereby increase accessibility for cellulase to lignocellulosic substrates. The discovery of more and more hemicellulose-active LPMOs and their contribution to breaking down the barriers by oxidatively acting on hemicellulose may expand our knowledge for their functions of LPMOs in lignocellulose biodegradation. [ABSTRACT FROM AUTHOR]

Rice husk is an abundant agricultural waste generated from rice production, but its application is limited. Considering its complex components, the rice husk was hydrolyzed by different enzymes to enhance its saccharification. In this study, saccharification of the rice husk by cellulase, xylosidase, and xylanase was first investigated. The synergistic effect of LPMO on the above hydrolases and different enzyme combinations in the saccharification process was then explored. Thereafter, the formulation of the enzyme cocktail and the degradation conditions were optimized to obtain the highest saccharification efficiency. The results showed that the optimum enzyme cocktail consists of Celluclast 1.5 L (83.3 mg/g substrate), the key enzymes in the saccharification process, worked with Bp Xyl (20 mg/g substrate), Bp Xyn11 (24 mg/g substrate), and R17L/N25G (4 mg/g substrate). The highest reducing sugar concentration (1.19 mg/mL) was obtained at pH 6.0 and 60 ℃ for 24 h. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to characterize the structural changes in the rice husk after degradation. The results showed that the key chemical bonds in cellulose and hemicellulose were broken. This study illuminated the concept of saccharifying lignocellulose from rice husk using LPMO synergistically assisted combined-hydrolase including cellulase, xylosidase, and xylanase, and provided a theoretical basis for lignocellulose biodegradation. • Synergistic effect of xylanase and xylosidase with cellulase is identified to saccharify rice husk. • LPMO can synergize with the above three hydrolases to saccharify rice husk. • A combination of all four enzymes provided 1.19 mg/mL of reducing sugar production. • The conditions of the degradation process are optimized. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Cellulose is converted to glucose in yield of 83% by WCl 6 in [BMIM]Cl at 70 °C. • Nature cellulose and lignocelluloses can be degraded by WCl 6 in high yield of TRS. • WCl6 can interact with aldehyde O in cellulose to break the 1,4-glucosidic bond. Abstract Degradation of cellulose to reducing sugar is the key step for the conversion of cellulose to valuable chemicals. Cellulose was degraded by WCl 6 in 1-butyl-3-methyl imidazole chloride at 80 °C and lower. 83% and 85.5% yield of total reducing sugar was gotten at 70 and 80 °C, respectively. Compared with inorganic acid, heteropoly acid, acidic ionic liquid and other metal chlorides, WCl 6 has shown better catalytic performance for degradation of cellulose to reducing sugar. The effect of reaction temperature, reaction time, WCl 6 amount and cellulose concentration were investigated. Degradation of cellulose by WCl 6 in 1-butyl-3-methyl imidazole chloride is a zero reaction. WCl 6 also showed excellent catalytic performance for the degradation of nature cellulose and lignocellulose. Catalyst can be reused at least 5 times without decrease of reducing sugar yield. The mechanism of degradation of WCl 6 was also suggested. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel biotechnology combined Fe 3 O 4 NMs and fungal treatment was proposed. • Possible mechanism of enhanced Fenton process was discussed. • Interaction between Fe 3 O 4 NMs and microorganisms was illustrated. • Decrystallization of lignocellulose by fungal treatment was observed. Abstract Nowadays, Nano-biotechnology is emerging to be one of the most promising tools in environmental remediation. In this study, the degradation efficiency of lignocellulose by white-rot fungi was improved by addition of Fe 3 O 4 nanomaterials (NMs) in solid-state fermentation. The highly-ordered cellulose crystalline was demonstrated to be broken down through infrared spectroscopy (FT-IR) and crystallinity index analysis. The decay of fluorescence intensity presented a lower degree of aromatic polycondensation and less conjugated chromophores in lignocellulose. Mechanistic analysis showed that NMs participated in the Fenton reaction and affected lignocellulose biodegradation process by regulating enzyme secretion. Specifically, the time variation curves of hydroxyl radicals and Fe2+ were discussed to illustrate the degradation pattern. The NMs remained stable after the fermentation and were possible to be recycled for the next cycle. All the results support that the synergism of Fe 3 O 4 NMs and white-rot fungi would be a promising research direction in lignocellulose treatment. [ABSTRACT FROM AUTHOR]

Abstract Symbionts in the gut of termites are expected to be large sources of enzymes involved in lignocellulose degradation, but their biotechnological potential has not been fully explored. In this study, we expressed, purified, and biochemically characterized a glycoside hydrolase family 11 xylanase, NtSymX11, from a symbiotic bacterium of the higher termite, Nasutitermes takasagoensis. NtSymX11 is a multimodular enzyme consisting of a catalytic domain and two tandem carbohydrate-binding modules (CBM36). The pH and temperature optima of NtSymX11 were pH 6.0 and 40 °C, respectively. By comparing the properties of full-length and truncated variants of NtSymX11, it was shown that CBM36 decreases the enzyme stability at acidic pH and high temperature. The main products from xylohexaose and various xylan substrates were X1-X3 xylooligosaccharides. Analysis of kinetic parameters indicated that NtSymX11 displays an outstanding catalytic performance when compared to other reported xylanases, and CBM36 enhances the activity by increasing the affinity to the substrate. Addition of Ca2+ boosted the activity of full-length enzyme, but not the truncated variant lacking the CBM, against the insoluble substrate, suggesting that CBM36 plays a role in the Ca2+-dependent increase of catalytic efficiency. Graphical abstract Image 1 Highlights • A GH11 xylanase, NtSymX11, from a termite symbiotic bacterium was characterized. • NtSymX11 consists of a catalytic domain and two tandem CBM36s. • NtSymX11 displayed a prominent catalytic performance compared to other xylanases. • CBM36 decreased the enzyme stability at acidic pH and high temperature. • CBM36 increased the activity to the insoluble substrate in a Ca2+-dependent manner. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Actinomycetes were added into straw composting from wheat, rice, corn and soybean. • Bacterial and actinomycetic community composition were analyzed during composting. • Key factor affecting lignocellulose degradation and enzyme activities were discerned. • Inoculation increased 34.3% lignocellulose degradation and 8.3% enzyme activity. • Combined adding inoculants and urea was suggested to improve the inoculation effect. Abstract This study was conducted to assess the effect of thermophilic actinomycetes inoculation on the lignocellulose degradation, enzyme activities and microbial community during different types of straw composting from wheat, rice, corn and soybean. The results showed that actinomycetes inoculation not only changed the structure of actinomycetic and bacterial community but also accelerated the degradation of cellulose, hemicellulose and lignin and increased the key enzymes activities including CMCase, Xylanase, manganese peroxidase, lignin peroxidase and laccase during composting particularly from wheat straw and rice straw. The key enzyme and physiochemical parameters which affected organic fractions degradation have been identified by redundancy analysis. The combined application of actinomycete inoculation and urea addition as a source of nitrogen was suggested to regulate the key enzyme activities and lignocellulose degradation, which lays a foundation for effectively managing organic wastes from different types of crop straws by composting. [ABSTRACT FROM AUTHOR]

Abstract The characteristics of bio-oil produced from biomass pyrolysis can be improved by co-feeding waste materials. In this work, co-pyrolysis of lignocellulosic biomass with six different waste plastics (waste tyre (WT), polylactic acid (PLA), polystyrene (PS), polyethylene terephthalate (PET), polypropylene (PP) and high density polyethylene (HDPE)) were conducted in a thermogravimetric analyser to study thermal decomposition of the mixtures. The distributed activation energy model (DAEM) was applied to pure feedstocks at 5 and 10 °C/min heating rates to fit the kinetic parameters. The model was used to simulate the co-pyrolysis of biomass/plastic mixtures assuming additive effect of components at different weight proportions and heating rates. Profiles of the fraction of mass remaining for mixtures at 100 °C/min were reproduced with a remarkable agreement. Discrepancies between the experimental and calculated profiles were considered as a measure of the extent of interactions occurring in the co-pyrolysis. Projections of the behaviour of mixtures under flash pyrolysis conditions were performed to study important aspects of the process, such as radical interactions and optimum working temperature. Highlights • The Distributed Activation Energy Model was applied to co-pyrolysis. • Mixtures of lignocellulosic biomass and plastic wastes were studied. • Different proportions of components and heating rates were successfully simulated. • Deviations of simulations from experiments were ascribed to interactions of solids. • Interactions depend on the nature and proportion of plastics and the heating rate. [ABSTRACT FROM AUTHOR]

Abstract The efficiency of enzymatic hydrolysis is reduced by the naturally recalcitrant complex polymers comprising lignocellulose. Increasing enzymatic conversion, which the complex macromolecules converted into simpler molecules, is still had to be overcome. High hydrostatic pressure (HHP), an emerging technology, is expected to ameliorate the situation. The effects of enzymatic hydrolysis after HHP pretreatment on pumpkin lignocellulose were studied and compared with hydrothermal and alkaline pretreatment. Further investigation was performed to evaluate the effect of enzymatic hydrolysis of pumpkin combined with HHP treatment. The samples underwent HHP treatment simultaneously exhibited overall better performance in enzymatic hydrolysis than the untreated. The highest glucose yield of 91.2% and xylose yield of 84.2% was achieved when 400 MPa HHP with high enzyme loading was applied. HHP exerted positive effects on enzyme-substrate interactions during the enzymatic hydrolysis of lignocellulose, which implied that HHP technology combined with enzymatic hydrolysis could be used to pretreat pumpkin pomace. Highlights • Cellulose and hemicellulose removal significantly increased after hydrothermal and alkaline pretreatment. • The highest yields of glucose and xulose were achieved at 400 MPa with high enzyme loading. • High hydrostatic pressure exerted positive effects on enzyme-lignocellulose complex interactions. • The method of high hydrostatic pressure was established on the conversion of lignocellulose. [ABSTRACT FROM AUTHOR]

The generation of a complex microbial consortium is a promising approach for efficient biomass decomposition. An anaerobic thermophilic alkaliphilic microbial consortium with efficient degradation ability was screened from bovine manure compost using non-pretreated milling corn stover (CS) and rice straw (RS). A stable microbial consortium ISHI-3 with high degradation ability for CS and RS was isolated by the roll tube technique. ISHI-3 comprised Herbivorax saccincola and bacteria belonging to the classes Pelotomaculum, Tepidanaerobacter , and Tepidimicrobium , as determined by DGGE of the PCR-generated 16S rRNA genes. Furthermore, metagenomics analysis using a 16S rRNA library was carried out to determine the bacterial distribution during degradation of CS and RS. H. saccincola and bacteria belonging to Pelotomaculum were relatively abundant in the beginning to middle periods of culture with CS and RS whereas bacteria belonging to Tepidanaerobacter and Tepidimicrobium gradually increased in the population during the later stages. To understand the role of non-cellulolytic bacteria in the consortium, novel strains ET1 and GL4, which were most closely related to Tepidimicrobium ferriphilum and Tepidanaerobacter acetatoxydans , were isolated from ISHI-3. Based on their carbon source usage, morphology, and phylogenetic analysis, we propose that strains ET1 and GL4 should be classified as a novel genus or species. Bacteria ET1 and GL4 can utilize different organic compounds as carbon and energy sources such as organic acids, alcohols, sugars, and amino acids, showing a preference for organic acids and alcohols rather than sugars such as glucose and cellobiose. These results indicated that ET1 and GL4 help to accelerate efficient lignocellulose degradation of H. saccincola . [ABSTRACT FROM AUTHOR]

Abstract Penicillium purpurogenum grows on a variety of natural carbon sources and secretes to the medium a large number of enzymes that degrade the polysaccharides present in lignocellulose. In this work, the gene coding for a novel xylanase (XynC) belonging to family 30 of the glycoside hydrolases (GH), has been identified in the genome of the fungus. The enzyme has been expressed in Pichia pastoris and characterized. The mature XynC has 454 amino acid residues and a calculated molecular weight of 49 240. The purified protein shows a molecular weight of 67 000, and it is partially deglycosylated using EndoH. Its pH optimum is in the range of 3–5, and the optimal temperature is 45 °C. It is active on both arabinoxylan and glucuronoxylan, similarly to other fungal GH 30 xylanases. It liberates a set of oligosaccharides, which have been detected by thin-layer chromatography, thus indicating that it is an endo-acting xylanase. It hydrolyzes xylooligosaccharides, releasing mainly xylobiose, in contrast to other fungal GH family 30 enzymes which generate chiefly xylose. Highest sequence identity to a characterized family 30 xylanase is found with the enzyme from the fungus Bispora sp (53%). This is the first GH 30 xylanase described from a Penicillium. Graphical abstract Thin layer chromatography of the hydrolysis products generated by XynC when acting on xylo-oligosaccharides. Lane 1: xylose. Lane 2: xylose + XynC. Lane 3: xylobiose. Lane 4: xylobiose + XynC. Lane 5: xylotriose. Lane 6: xylotriose + XynC. Lane 7: xylotetraose. Lane 8: xylotetraose + Xyn C. Lane 9: xylopentaose. Lane 10: xylopentaose + XynC. Lane 11: xylohexaose. Lane 12, xylohexaose + XynC. Image 1 Highlights • The gene of a family 30 xylanase was found in the genome of Penicillium purpurogenum. • The enzyme (XynC) was heterologously expressed in Pichia pastoris. • XynC is active on a variety of xylans and on xylooligosaccharides. • In contrast to other GH 30 xylanases, it liberates xylobiose in preference to xylose. [ABSTRACT FROM AUTHOR]

Biological pretreatment with novel isolated microbial pure culture was utilised to pretreat water hyacinth to enhance its solubilisation followed by biogas production. Lignocellulose degrading bacterial strains isolated from soil ( Bordetella muralis VKVVG5 ) (UN3d2), the gut of silverfish ( Citrobacter werkmanii VKVVG4 ) (SFa2) and millipede ( Paenibacillus sp. VKVVG1 ) (BrB2) were employed to optimise the ideal bacterial strain illustrating accelerated hydrolysis of water hyacinth. Citrobacter werkmanii VKVVG4 pretreatment of water hyacinth with an optimum dosage of 10 9  CFU/mL and time of 4 days helped in achieving the highest solubilisation of 33.3%. Biochemical methane potential (BMP) test was conducted between untreated and Citrobacter werkmanii VKVVG4 pretreated water hyacinth. Biochemical methane potential (BMP) test of pretreated water hyacinth illustrated faster start up period than the untreated water hyacinth. Citrobacter werkmanii VKVVG4 (SFa2) pretreated water hyacinth illustrated a cumulative biogas production of 3737 ± 21 mL whereas untreated water hyacinth illustrated a cumulative biogas production of 3038 ± 13 mL on the 50 th day. Scaled up batch (20 L) study demonstrated a three times increase in the cumulative biogas generation of the microbial pretreated water hyacinth than the untreated water hyacinth. [ABSTRACT FROM AUTHOR]

Abstract Anaerobic digestion is a feasible method for vinegar residue disposal. However, its treatment efficiency is limited significantly by the low degradation of lignocellulose. In this study, a stable and efficient anaerobic digestion system for vinegar residue was constructed. The continuous solid-state reactor achieved a specific production of 418 mL·g-1 VS biogas and 223 mL·g-1 VS methane at a high organic loading rate (OLR) of 5.83 g VS ·(L·d)−1. The stable degradation of lignocellulose between 39.5% and 36.4% was key factor for stable anaerobic digestion at high OLR. This stability under optimum OLR was due to the increase in the degradation of hemicellulose, which compensated for the loss of lignocellulose degradation. The enrichment of microorganism related to lignocellulose hydrolysis and the stable microbial community structure ensured efficient anaerobic digestion under high OLR condition. Digestion efficiency can be further improved mainly by increasing cellulose degradation. This investigation provided the theoretical basis for practical application of this digestion system for solid vinegar residue treatment. Graphical abstract Image 1 Highlights • A stable efficient anaerobic digestion system via vinegar residue was constructed. • Optimum organic loading rate reached up to 5.83g VS ·(L·d)−1. • Increasing of hemicellulose hydrolysis rate stabilized system efficiency. • Potential improvement on efficiency was depended on cellulose released and hydrolysis. • Growth and uniform distribution of hydrolysis microbes ensured system efficiency. [ABSTRACT FROM AUTHOR]

This research aims to provide a better knowledge of the thermal decomposition of the olive cake as well as this lignocellulosic material loaded, in a previous stage of biosorption, with heavy metals for its use in processes of energy recovery. Firstly, isolation of constituents of the olive cake was carried out. Then, experiments were performed by thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) under inert and oxidative atmosphere at a heating rate of 15 K/min for each isolated fraction. Next, adequate reactions schemes were proposed to find kinetic parameters. Validation of these schemes were verified by the goodness of fitting between experimental and simulated data. Also, some important combustion characteristics such as ignition and burnout temperatures were determined. With regard to the effect of metals, cadmium, copper, chromium, nickel and lead present in metal-loaded olive cake did not modify values of kinetic parameters which described the thermal decomposition processes. [ABSTRACT FROM AUTHOR]

The suitability of three local lignocellulosic wastes i.e. almond shell (AS), rice husk (RH) and seagrass (SG) as fillers in PHB/Fiber composites applications has been studied. PHB/Fiber composites with 10 phr and 20 phr fiber content were prepared by melt blending. The influence of the fiber type (size, morphology and origin) and content on the morphological, mechanical and thermal properties of the as obtained composites has been assessed. To evaluate the potential use in food packaging applications, the barrier performance to water, thermoforming ability and disintegration in controlled composting conditions of the composites were also studied. All the fibers have demonstrated to be apt for their use as fillers in PHB/Fiber composites, showing a reinforcing effect without affecting the crystallinity and the disintegration rate of PHB. The thermal stability and the water barrier performance of the composites were reduced by the presence of the fibers. Nevertheless, the addition of AS resulted in the best balance of properties, in terms of permeability and mechanical properties, finding an enhancement of the thermoforming ability of PHB when 10 phr of AS was added. [ABSTRACT FROM AUTHOR]

The thermal properties of cellulose, hemicellulose and lignin can be utilized to improve the characteristics of pyrolysis liquids. In this study, a concept of stepwise pyrolysis to fractionate the liquid based on the thermal properties of the biomass constituents was investigated. Lignocellulosic biomass was thermally treated in two steps: 200–300 °C followed by 550 °C. Derived liquids were studied for GC/MS analysis, water content, acid concentration and a solvent extraction method. Pyrolytic liquid derived from 550 °C after treatment at lower temperatures have a higher relative composition of phenolic compounds compared to one-step pyrolysis (increased from 58 to 90% of GC/MS peak area). Also, compounds known to promote aging, such as acids and carbonyl compounds, are derived at lower temperatures which may suppress aging in the liquid derived downstream at 550 °C. For liquids derived at 550 °C, the total acid number was reduced from 125 in one-step treatment to 14 in two-step treatment. Overall, no significant difference in the total liquid yield (sum of the liquids derived in separated treatments) nor any variations in their collective composition compared to one-step treatment at 550 °C was observed, i.e. stepwise pyrolysis can be utilized for direct fractionation of pyrolytic vapors. [ABSTRACT FROM AUTHOR]

In this study, the rate of xylan hydrolysis was investigated. The hydrolysis of tulip poplar was conducted in subcritical water from 180 to 220 °C for 1–240 min. An equation for estimating the hydrolysis of ether bonds in both xylan and xylooligosaccharide from the yield of xylan and xylooligosaccharide was derived, and the rate constant of ether bond hydrolysis was calculated using the derived equation. It was found that our kinetic study can be applied to subcritical water treatment of various lignocellulosic biomass. In addition, linearity between the apparent activation energy and the logarithmic value of the apparent pre-exponential factor was observed. An equation for the apparent reaction rate constant was derived by introducing a factor, α, that reflects the changes in the reaction rate arising from various factors. [ABSTRACT FROM AUTHOR]

In this study, the gene fusion of endoglucanase (EG, one of cellulases) from Teleogryllus emma and xylanase (Xyn, one of hemicellulases) from Thermomyces lanuginosus was constructed to generate a fusion enzyme (EG-M-Xyn). Through the expression and purification by ultrafiltration and size-exclusion chromatography, the purified EG-M-Xyn had a molecular weight of 75.5 kDa and exhibited the specific activity of CMCase and xylanase as 306.8 U/mg and 1227.3 U/mg, respectively. The K m values (CMC and beechwood xylan) were 6.8 and 60.6 mg mL −1 while catalytic efficiency ( k cat / K m ) values of CMCase and xylanase were 3280 and 38,797 min −1  mg −1  mL, respectively. EG-M-Xyn exerted great properties for its great potential in improving the enzymatic hydrolysis of lignocellulosics to produce fermentable sugars. First, EG-M-Xyn showed mild reaction pH and temperature of 5.5 and 50 °C, respectively. Secondly, EG-M-Xyn exhibited great heat tolerance of T 1/2 values of 173 (CMCase) and 693 min (xylanase). Lastly and most importantly, application of EG-M-Xyn in combination with Ctec2 (commercial enzyme) in the saccharification led to a 10–20% net increase in fermentable sugars liberated from pretreated rice straw in comparison to the Ctec2 alone group. In conclusion, EG-M-Xyn had great potential in generating fermentable sugars from renewable agro-residues for biofuel and fine chemical industry. [ABSTRACT FROM AUTHOR]

Oil palm trunk (OPT) is one of the most promising lignocellulosic bioresources. To develop effective biodegradation, thermophilic, anaerobic microorganisms were screened from bovine manure compost using fibrillated OPT (f-OPT) pretreated by wet disk milling as the substrate. One thermophilic, anaerobic bacterium, strain CL-2, whose 16S rDNA gene has 98.6% sequence identity with that of Caldicoprobacter faecale DSM 20678 T , exhibited high degradation activity (32.7% reduction in total dry solids of f-OPT). Strain CL-2 did not use cellulose as a carbon source, but used hemicelluloses such as xylan, arabinoxylan, starch and pectin at 70 °C. Phylogenetic and morphologic analyses and the polysaccharide use suggest that CL-2 may be classified as a novel species of Caldicoprobacter , named Caldicoprobacter sp. CL-2. To characterize enzymatic activities of CL-2, extracellular enzymes were prepared from culture broth using beechwood xylan as the carbon source. The extracellular enzymes showed high xylanase activity, but low cellulase activity, suggesting that f-OPT degradation may depend on xylanase activity. To understand the xylanase system of CL-2, a major xylanase was cloned and characterized. The xylanase ( Cal Xyn11A) had a modular structure consisting of a glycoside hydrolase (GH) family-11 domain and a family 36 carbohydrate-binding module. Cal Xyn11A did not show f-OPT degradation activity, but a strong synergistic effect was observed when Cal Xyn11A was added to the extracellular enzyme preparation. These results indicate that, rather than working alone, Cal Xyn11A has an important role in enhancing total lignocellulose degradation activity by cooperation with other GHs. [ABSTRACT FROM AUTHOR]

To maintain our society’s sustainability with respect to people, prosperity, and the planet, we must produce liquid transportation fuels such as bioethanol on the renewable basis at a competitive price to petroleum-based fuels. The major challenges to commercialize cellulosic biofuels are low fermentation efficiency, low ethanol titer, and lack of technology to fully utilize the byproduct from bioconversion process such as lignin which has been underutilized. To overcome these technical barriers, we have proposed a novel design to fully utilize each component of lignocellulosic biomass for biofuels and bio-chemicals production, which involves green technologies such as hydrothermal and organosolv pretreatments to produce a cellulose-rich solid with good recovery of clean lignin after solvent recycling for improvement of plant protein-based adhesives as well as xylose remained in the aqueous phase for furfural upgradation. The focus of this study, as a part of the whole biorefinery concept, is to develop modified simultaneous saccharification and fermentation (mSSF) to enhance ethanol titers and yields, which combines the advantages of both separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) via unique decantation process. The mSSF achieved higher ethanol concentration of 58.5 g/L and ethanol yield of 83.5% as compared to the traditional SSF process (49.9 g/L and 71.1%) at the biomass loadings of 20% (w/v). The mSSF also enabled higher ethanol titers of 72.3 g/L at higher loadings of 30% (w/v) with yields of 70.0%. As compared to published high-gravity fermentation, ethanol concentration of 72.3 g/L achieved in this study was the highest one in the lab-scale process, which proved that the proposed mSSF was an effective process to increase ethanol titers without sacrificing ethanol yields. The improved ethanol titers and yields would significantly lower the distillation cost and accelerate the commercialization of cellulosic biofuel production. [ABSTRACT FROM AUTHOR]

For cost-effective lignocellulosic biofuel/chemical production, consolidated bioprocessing (CBP)-enabling microorganisms utilizing cellulose as well as producing biofuel/chemical are required. A novel strain Paenibacillus sp. CAA11 isolated from sediment was found to be not only as a cellulose degrader under both aerobic and strict anaerobic conditions but also as a producer of cellulosic biofuel/chemicals. Paenibacillus sp. CAA11 secreted cellulolytic enzymes by its own secretion system and produced ethanol as well as short-chain organic acids (formic acid, acetic acid, lactic acid) from cellulose. Cellulolytic activity of the strain was significantly enhanced by expressing a heterologous endoglucanase 168Cel5 from Bacillus subtilis under both aerobic and anaerobic conditions. The strain harboring the 168cel5 gene revealed 2-fold bigger halo zone on Congo-red plate and 1.75-fold more aerobic cellulose utilization in liquid medium compared with the negative control. Notably, under anaerobic conditions, the recombinant strain expressing 168Cel5 consumed 1.83-fold more cellulose (5.10 g/L) and produced 5-fold more ethanol (0.65 g/L) along with 5-fold more total acids (1.6 g/L) compared with the control, resulting 2.73-fold higher yields. This result demonstrates the potential of Paenibacillus sp. CAA11 as a suitable aerobic and anaerobic CBP-enabling microbe with cellulolytic production of ethanol and short-chain organic acids. [ABSTRACT FROM AUTHOR]

Rice straw (RS) is one of the most abundant lignocellulosic biomasses in China, which contains mainly of cellulose, hemicellulose and lignin. In this study, a novel deep eutectic solvent (DES), foraceline, was prepared with choline chloride and double hydrogen bond donors (formic acid and acetic acid). By combining foraceline and sodium carbonate (1%), a two-stage pretreatment method was developed and applied in RS pretreatment to improve the biodegradability of lignocellulose. The highest glucose and total sugar of 37.3 g·L −1 and 42.8 g·L −1 were obtained after hydrolysis of 24 h using 50 FPU· g total solid - 1 of cellulase. The cellulase attached to RS was reutilized for five continuous cycles in which enzyme loading was reduced from 50 FPU· g total solid - 1 (Cycle I) to 30 FPU· g total solid - 1 (Cycle V), resulting in total sugar of 41.3–42.6 g·L −1 for each cycle. RS hydrolysates (Cycle I and V) was utilized in butanol fermentation by Clostridium saccharobutylicum DSM 13864, achieving butanol titer and yield of 9.5 g·L −1 and 0.25 g· g total sugar - 1 , similar to those of glucose medium. This study demonstrated the feasibility of this newly developed biomass pretreatment by dihydrogen bonding DES featuring cellulase recycling and high butanol yield. [ABSTRACT FROM AUTHOR]

To achieve industrial ( R,R )-2,3-butanediol (( R,R )-2,3-BDL) production from various lignocellulosic biomass, it is essential to develop an efficient fermentation process to overcome the challenge of carbon catabolite repression (CCR). The present study comprehensively investigated the effects of different glucose/xylose mixtures and fermentation strategies on ( R , R )-2,3-BDL production using a nonpathogenic strain of Paenibacillus polymyxa . In both batch and fed-batch mode, we observed slow sugar utilization and a lower productivity. By employing cell-recycling continuous fermentation system for ( R , R )-2,3-BDL production from mixed sugar, the volumetric productivity was significantly increased, by an average of 2-fold higher compared to alternative fermentation modes. Moreover, the ( R , R )-2,3-BDL titer, volumetric productivity and yield achieved 18.80 g/l, 1.13 g/l/h and 0.313 g/g when corn stover hydrolysates (CSH)was used as substrate. The results suggested that the reported fermentation system could efficiently eliminate CCR to improve ( R , R )-2,3-BDL productivity. Thus, it had great potential for the industrial-scale ( R , R )-2,3-BDL production from lignocellulosic hydrolysates. [ABSTRACT FROM AUTHOR]

Xylitol is a by-product that is obtained from the production of bioethanol. A lignocellulosic biomass contains an abundance of xylose that acts as a precursor in the production of xylitol. The xylitol produced from biomass sources through biological route is a cleaner production than the common chemical route, which involves least sustainable processes. However this xylitol may contain other impurities and sugars that are difficult to separate due to their close molecular weights. A highly concentrated xylitol can potentially be obtained through the use of a pressure filtration membrane as a potential cleaner production technology due to the unique properties of the membrane including low energy requirement, high separation performance, and high selectivity between xylitol and sugars. In this work, a specially blended polymeric membrane was synthesized, characterized and tested in the recovery of xylitol from a synthetic biomass fermentation solution. Pluronic f127 at different ratios of 1, 3, and 5% was blended with Polyethersulfone (PES) to modify the PES membrane. The effect of the Pluronic ratio on the selectivity of the PES membrane in the separation of xylitol from sugars and also the fouling mitigation effect under the presence of Pluronic in the membrane were investigated. The results showed an improvement in the hydrophilicity of the membrane, where the contact angle of the pure PES membrane dropped from 80° to 65° following the addition of Pluronic at different ratios. The water flux also increased with an increase in the Pluronic ratio. The rejection of xylitol was found to decrease in the presence of Pluronic, and a reasonable xylitol selectivity was obtained. Surprisingly, the selectivity of the membrane towards xylitol was further enhanced by the presence of ethanol in the synthetic fermentation solution. Therefore, the PES blended Pluronic membrane was shown to have a great potential for the separation of xylitol from sugars. [ABSTRACT FROM AUTHOR]

The rapidly increasing human population poses a serious risk of fast depletion of natural resources like fossil fuels. Therefore, production of ecofriendly renewable alternatives like biofuels from waste materials has sparked more curiosity from the industrialists as well as academicians. Similarly, production of bioenergy from agricultural wastes is gaining interest worldwide. In view of the above objective, cellulose degrading bacterium G9-KDP isolated from the crop fluid of giant African land snail, Achatina fulica was identified as Bacillus tequilensis based on 16S rRNA gene sequencing. The B. tequilensis G9 produced cellulase with the highest activity of 956.9 IU/ml extract on 8 th day of incubation when grown in BMS medium induced by sugarcane bagasse. The optimal temperature and pH of the organism were 60 °C and 6.6, respectively. It was observed that the activity of crude enzyme was affected to various extents by different metal ions. The activity was inhibited by Co 2+ and Ca 2+ at 5 mM concentrations but enhanced by K + and Mn 2+ ions. However, EDTA at 1% concentration increased the activity by 94% while SDS reduced it by 57% at the same concentration. Scanning electron microscopy of the filter paper used as substrate revealed significant structural modifications after the treatment with bacteria. The degradation of the various cellulosic compounds into simpler sugars by this isolate brands its potential applications in industrial biotechnology. [ABSTRACT FROM AUTHOR]

This work proposes an original innovative in-house device able to characterize the evolution of viscoelastic properties of lignocellulosic products during hydrothermal pretreatment (water-saturated conditions up to 190 °C). The main objective is to assess the cooking phase before steam explosion. We designed and built a novel experimental device for analyzing the dynamic mechanical analysis of the biomass soaked in water or acidic water. The device allows the sample to be loaded/unloaded during the test with an accurate measurement of deformation and force despite the severe conditions. This system can perform the mechanical test on immersed samples under controlled pressure (up to 1.5 MPa) and temperature (up to 190 °C). Experiments were performed with poplar via harmonic and periodic tests. The experimental data collected on poplar allows the characteristic time constants of the thermo-chemical reactions to be obtained as a function of the operating conditions. [ABSTRACT FROM AUTHOR]

Pretreatment is necessary to improve methane production from lignocellulosic biomass. Urea was adopted to pretreat wheat straw with the advantages of structure deconstruction, its nitrogen source, and prevention of pH drop in subsequent anaerobic digestion (AD). Scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR) spectra measurements indicated that urea pretreatment is able to degrade the lignocellulosic structure, which was beneficial for the improvement of methane production. Urea pretreatment led to the satisfactory performance of AD with wheat straw as substrate. The maximum methane production of 305.5 L/kg volatile solids (VS) was obtained using 1% (w/w) urea loading, which was 45.2% higher than the untreatment. After 1%- and 3%-urea treatment, time used for achieving stable status (≥50%) was 2 days earlier compared to untreatment. Reductions of total solids (49.4%), VS (54.5%), cellulose (50.4%) and hemicelluloses (47.3%) on the optimal condition were the highest, which were 36.8%, 46.5%, 33.3% and 47.4% higher compared to untreatment. Higher levels of urea pretreatment (3% and 5%) were less efficient and resulted in the formation of pseudo-lignin according to FTIR. These results indicate that wheat straw can be used to produce methane significantly with urea pretreatment. [ABSTRACT FROM AUTHOR]

The outstanding degrading abilities of Phanerochaete chrysosporium is solely dependent on its lignocellulolytic, aromatic compound degrading and detoxifying enzymes. However, the gene expression and protein turnover of lignocellulolytic enzymes are controlled at cellular level by various genes involved in information storage and processing KOG group. Understanding the gene expression patterns and mechanisms involved in regulation of lignocellulose degrading enzymes will significantly help in strain improvement and developing recombinant strains. To study the common expression patterns, we have retrieved P. chrysosporium gene expression datasets from NCBI GEO and analyzed using GeneSpring ® software based on the genome wide KOG annotations retrieved from JGI-MycoCosm database. Statistically significant genes obtained from our analysis were separated into replication, repair and recombination, chromatin structure and dynamics, transcription factors, RNA processing and modification and translation, ribosomal structure and biogenesis processes. We have observed various genes encoding for DNA damage, repair and recombination, mRNA splicing, amidases, polyadenylate binding factors, heat shock, helix loop helix, HMG-box, CCAAT (HAP5), CRE-B transcription factors, histone acetyl transferases (MYST, SAGA) commonly expressed among the datasets of natural plant biomass growth substrates. Further studies must be conducted to understand the role and involvement of these significant genes in plant biomass degradation by P. chrysosporium. [ABSTRACT FROM AUTHOR]

Ultrasound irradiation has been gaining increasing interests over the years to assist biological conversion of lignocellulosic biomass and waste materials to biofuels. As such, this study reviewed the different effects of sonication on pre-treatment of lignocellulosic biomass and waste materials prior to biofuel production. The mechanisms of ultrasound irradiation as a pre-treatment technique were initially described and the impacts of sonication on disruption of lignocellulosic materials, alteration of the crystalline lattice structure of cellulose molecules, solubilisation of organic matter, reducing sugar production and enzymatic hydrolysis were then reviewed. Subsequently, the influences of ultrasound irradiation on bio-methane, bio-hydrogen and bio-ethanol production were re-evaluated, with most studies reporting enhanced biofuel production from anaerobic digestion or fermentation processes. Nonetheless, despite its positive impacts on biofuel production, sonication was found to be energetically inefficient based on the lab-scale studies reviewed. To conclude, this study reviewed some of the challenges of ultrasound irradiation for enhanced biofuel production while outlining some areas for further research. [ABSTRACT FROM AUTHOR]

The thermal behavior and kinetic study of lignocellulosic biomass (rice straw (RS)) and linear low-density polyethylene (LLDPE) pyrolysis over modified ZSM-5 catalyst were investigated using thermo-gravimetric analysis (TGA). Cellulose and lignin were used as model compounds of biomass in order to investigate the reaction mechanism of lignocellulosic biomass and polyethylene co-pyrolysis. Results showed that RS&LLDPE co-pyrolysis was more complicated than that of the individual components. The activation energy (E) of RS, and RS&LLDPE pyrolysis were 79.61 kJ/mol and 59.70 kJ/mol respectively, suggesting that there was a positive synergistic interaction between RS and LLDPE. The addition of LLDPE with lignin co-pyrolysis obtained a lower apparent activation energy (33.39 kJ/mol) compared to raw lignin pyrolysis (53.10 kJ/mol). Results indicated that the Cobalt modified ZSM-5 catalyst was able to improve the reaction rate of RS and LLDPE co-pyrolysis; also the addition of Co/ZSM-5 catalyst resulted in a lower apparent activation energy during cellulose and LLDPE co-pyrolysis. [ABSTRACT FROM AUTHOR]

D . squalens , a white-rot fungus that efficiently degrades lignocellulose in nature, can be used in various biotechnological applications and has several strains with sequenced and annotated genomes. Here we present a method for the transformation of this basidiomycete fungus, using a recently introduced commercial ascomycete protoplasting enzyme cocktail, Protoplast F. In protoplasting of D . squalens mycelia, Protoplast F outperformed two other cocktails while releasing similar amounts of protoplasts to a third cocktail. The protoplasts released using Protoplast F had a regeneration rate of 12.5% (± 6 SE). Using Protoplast F, the D . squalens monokaryon CBS464.89 was conferred with resistance to the antibiotics hygromycin and G418 via polyethylene glycol mediated protoplast transformation with resistance cassettes expressing the hygromycin phosphotransferase ( hph ) and neomycin phosphotransferase ( nptII ) genes, respectively. The hph gene was expressed in D . squalens using heterologous promoters from genes encoding β-tubulin or glyceraldehyde 3-phosphate dehydrogenase. A Southern blot confirmed integration of a resistance cassette into the D . squalens genome. An average of six transformants (± 2 SE) were obtained when at least several million protoplasts were used (a transformation efficiency of 0.8 (± 0.3 SE) transformants per μg DNA). Transformation of D . squalens demonstrates the suitability of the Protoplast F cocktail for basidiomycete transformation and furthermore can facilitate understanding of basidiomycete gene function and development of improved strains for biotechnological applications. [ABSTRACT FROM AUTHOR]

Production of biofuels from lignocellulosic biomass remains an unsolved challenge in industrial biotechnology. Efforts to use yeast for conversion face the question of which host organism to use, counterbalancing the ease of genetic manipulation with the promise of robust industrial phenotypes. Saccharomyces cerevisiae remains the premier host for metabolic engineering of biofuel pathways, due to its many genetic, systems and synthetic biology tools. Numerous engineering strategies for expanding substrate ranges and diversifying products of S. cerevisiae have been developed. Other yeasts generally lack these tools, yet harbor superior phenotypes that could be exploited in the harsh processes required for lignocellulosic biofuel production. These include thermotolerance, resistance to toxic compounds generated during plant biomass deconstruction, and wider carbon consumption capabilities. Although promising, these yeasts have yet to be widely exploited. By contrast, oleaginous yeasts such as Yarrowia lipolytica capable of producing high titers of lipids are rapidly advancing in terms of the tools available for their metabolic manipulation. [ABSTRACT FROM AUTHOR]

Microorganisms have evolved different and yet complementary mechanisms to degrade biomass in the biosphere. The chemical biology of lignocellulose deconstruction is a complex and intricate process that appears to vary in response to specific ecosystems. These microorganisms rely on simple to complex arrangements of glycoside hydrolases to conduct most of these polysaccharide depolymerization reactions and also, as discovered more recently, oxidative mechanisms via lytic polysaccharide monooxygenases or non-enzymatic Fenton reactions which are used to enhance deconstruction. It is now clear that these deconstruction mechanisms are often more efficient in the presence of the microorganisms. In general, a major fraction of the total plant biomass deconstruction in the biosphere results from the action of various microorganisms, primarily aerobic bacteria and fungi, as well as a variety of anaerobic bacteria. Beyond carbon recycling, specialized microorganisms interact with plants to manage nitrogen in the biosphere. Understanding the interplay between these organisms within or across ecosystems is crucial to further our grasp of chemical recycling in the biosphere and also enables optimization of the burgeoning plant-based bioeconomy. [ABSTRACT FROM AUTHOR]

Pretreatment is indispensable for the large-scale and low-cost bio-products production from lignocellulosic biomass. Herein, a new bacteria-enhanced dilute acid pretreatment (BE-DAP) strategy was introduced. Cupriavidus basilensis B-8 as a potential bacterium for lignin degradation was employed. Multi-scale characterizations on the physicochemical structure of rice straw indicated that Cupriavidus basilensis B-8 could act on the lignin droplets formed in dilute acid pretreatment (DAP), and dig out these droplets to recover cracks and holes on rice straw surface, leaving an opened and porous structure for the easy access of enzyme to inner cellulose. Eventually, the enzymatic digestibility of RS was increased by 35–70% and 173–244% in BE-DAP compared to DAP pretreated and untreated RS, respectively. The BE-DAP strategy, as well as its physicochemical mechanism, opened new perspectives for lignocellulose pretreatment. [ABSTRACT FROM AUTHOR]

Rapid urbanization and industrialization have accelerated the energy demand which cannot be met by decreasing fossil fuels thereby substantiate the need for lignocellulosic ethanol. The present study is one such attempt towards bioethanol production in an eco-friendly manner using enzymes in which a mixture of lignocellulosic biomass namely, Ricinus communis , Saccharum officinarum (tops) and Saccharum spontaneum were taken as a substrate. The mixed biomass was processed through partially consolidated bioprocessing (PCBP) approach which involves a non-isothermal simultaneous pretreatment and saccharification step where a concoction of laccase ( Pleurotus djamor ) and holocellulase ( Trichoderma reseei RUT C30) was used followed by co-fermentation within the same reactor. The process parameters influencing PCBP were optimized using feed-forward ANN model which resulted in a maximum ethanol concentration of 7.86% (v/v) (62.01 g/L) at pentose to hexose strain ratio of 0.696 (v/v), substrate loading of 27.54% (w/v) and incubation time of 21.96 h. [ABSTRACT FROM AUTHOR]

Biochemical conversion of lignocellulosic feedstock to biofuels and other valuable chemicals through sugar-platform process involves a pretreatment step that facilitates the conversion of polysaccharides to simple sugars. A major drawback of pretreatment process is the formation of lignocellulose-derived by-products, such as furfural and 5-hydroxy-2-methylfurfural (HMF), which inhibit the downstream enzymatic hydrolysis and microbial growth during fermentation. Hence, an efficient and environment friendly technique for removal of these inhibitors is essential. The present study reports isolation of a bacterium from soil that exhibited capability to degrade furfural and HMF present in lignocellulosic hydrolysate liquor. The isolated bacterium, Bordetella sp. BTIITR, was able to degrade 100% of furfural and 80% of HMF from simulated hydrolysate liquor in 16 h of incubation period. For the actual sugarcane bagasse hydrolysate liquor, it was able to remove 100% of furfural, 94% of HMF and 82% of acetic acid in 16 h of incubation period. It was also intriguing to observe that the bacterium selectively consumed furfural and HMF initially without significantly affecting the fermentable sugars. Once furfural and HMF were degraded to a lower concentration, consumption of sugars accelerated. This substrate priority of Bordetella sp. BTIITR for furfural and HMF over sugars renders it as a potential candidate for biodetoxification of inhibitory compounds present in the lignocellulosic hydrolysate liquor. [ABSTRACT FROM AUTHOR]

Previously, a unique co-compost produced by composting empty fruit bunch with anaerobic sludge from palm oil mill effluent, which contributed to establishing a zero-emission industry in Malaysia. Little was known about the bacterial functions during the composting process and fertilization capacity of this co-compost. We isolated 100 strains from the co-compost on 7 types of enumeration media and screened 25 strains using in vitro tests for 12 traits, grouping them according to three functions: plant growth promoting (fixation of nitrogen; solubilization of phosphorus, potassium, and silicate; production of 3-indoleacetic acid, ammonia, and siderophore), biocontrolling (production of chitinase and anti- Ganoderma activity), and composting (degradation of lignin, xylan, and cellulose). Using 16S rRNA gene sequence analysis, 25 strains with strong or multi-functional traits were found belong to the genera Bacillus , Paenibacillus , Citrobacter , Enterobacter , and Kosakonia . Furthermore, several strains of Citrobacter sedlakii exhibited a plant growth-stimulation in vivo komatsuna plant cultivation test. In addition, we isolated several multifunctional strains; Bacillus tequilensis CE4 (biocontrolling and composting), Enterobacter cloacae subsp. dissolvens B3 (plant growth promoting and biocontrolling), and C. sedlakii CESi7 (plant growth promoting and composting). Some bacteria in the co-compost play significant roles during the composting process and plant cultivation after fertilization, and some multifunctional strains have potential for use in accelerating the biodegradation of lignocellulosic biomass, protecting against Ganoderma boninense infection, and increasing the yield of palm oil. [ABSTRACT FROM AUTHOR]

Codon adaptation index (CAI) of a 1263 bp long endoglucanase encoding gene from the thermophilic mould Myceliopthora thermophile BJA has been improved from 0.44 to 0.76 by in vitro gene synthesis. The codon optimized endoglucanase gene ( Mt-egl ) has been constitutively expressed in Pichia pastoris under the regulation of GAP promoter. Recombinant endoglucanase (rMt-egl), purified by size exclusion chromatography, has been confirmed to be a monomeric protein of ∼47 kDa. rMt-egl is optimally active at pH 10 and 50 °C, displaying stability in broad pH and temperature ranges, with a t 1/2 of 60 and 15 min at 90 and 100 °C, respectively. This retained ∼70% of activity after 3 h incubation at pH 5–12. The K m , V max , k cat and k cat /K m of rMt-egl were 5 mg mL −1 , 20 μmoles min −1 mg −1 , 1.02 × 10 3 s −1 and 204 s −1 mg −1 mL −1 , respectively. Homology modeling and bioinformatics analysis confirmed catalytically important role of glutamate 234 and 344. rMt-egl released high amounts of reducing sugars from wheat bran and corn cobs (421 and 382 mg g −1 ), thus making it a useful biocatalyst for producing bioethanol and fine chemicals from agro-residues. [ABSTRACT FROM AUTHOR]

Some zwitterionic surfactants exhibit upper critical solution temperature (UCST) in aqueous solutions. For the zwitterionic surfactant solution mixed with cellulase, when its temperature is below UCST, the cellulase can be recovered by coprecipitation with zwitterionic surfactant. In this work, 3-(Hexadecyldimethylammonio) propanesulfonate (SB3-16) was selected to enhance the enzymatic hydrolysis of lignocelluloses and recover the cellulase. After adding 2 mmol/L of SB3-16, the enzymatic digestibility of eucalyptus pretreated by dilute acid (Eu-DA) and by sulfite (Eu-SPORL) increased from 27.9% and 35.1% to 72.6% and 89.7%, respectively. The results showed that SB3-16 could reduce the non-productive adsorption of cellulase on hydrophobic interface, while it did not significantly inhibit the activity of cellulase. For the solution contained 1 wt% SB3-16 and 200 mg protein/L CTec2 cellulase, 55.2% of protein could be recovered by cooling. The filter paper activity of the recovered cellulase was 1.93 FPU/mg protein, which was 95.8% of its initial activity. [ABSTRACT FROM AUTHOR]

Hospital wastewater is a major source of pharmaceutically active compounds (PhACs), which are not all removed in conventional wastewater treatment plants. White rot fungi can degrade PhACs, but their application has been limited to non-sterile conditions due to the competition with other microorganisms for growth. In this study, immobilization of Trametes versicolor on different lignocellulosic supports was studied as strategy to ensure fungal survival under continuous treatment conditions. A fluidized bed reactor and a trickling packed-bed reactor with T. versicolor immobilized on pallet wood were employed for the removal of ibuprofen, ketoprofen and naproxen. Best results were obtained with the trickling packed-bed reactor, which operated for 49 days with high removal values in real hospital wastewater. [ABSTRACT FROM AUTHOR]

The concept of an integrated biorefinery has increasing importance regarding sustainability aspects. However, the typical concepts have techno-economic issues: limited replacement in co-processing with fossil sources and high investment costs in integration to a specific plant. These issues have directed the current investigations to supply-chain network systems. On the other hand, these studies have the scope of a specific product and/or a feedstock type. This paper proposes a novel biorefinery concept for lignocellulosic biomass: sectoral integration network and a new hydrothermal process for biomass conversion. The sectoral integration concept has the potential for sustainable production from biomass: pre-treatment at the biomass sites, regional distributed conversion of biomass from various sectors (e.g. black liquor, sawdust, straw) and centralized upgrading/separation of crude biofuels. On the other hand, the conversion processes compose the vital part of such a concept. The new conversion involves partial wet oxidation - or simultaneous dissolution with partial wet oxidation for solid biomass- followed by lignin recovery with acidification and a reactor that can perform either hydrothermal liquefaction or supercritical water gasification. The process can intake both liquid and solid biomass to produce lignin as biomaterial and syngas or bio-oil. The new concept can contribute social development of rural areas by utilizing waste as valuable raw material for the production of multiple products and reduce the net greenhouse gas emissions by replacing fossil-based production. [ABSTRACT FROM AUTHOR]

Room-temperature ionic liquids (ILs) are molten salts at around room temperatures. The current researches of using ILs for efficient pretreatment for lignocellulosic biomass are updated in this article. The aspects of synthesis of high-performance ILs, recycling of used ILs with minimum use of utility, development of IL-tolerant enzymes, and optimization of the entire process economy were discussed. The mechanisms of IL solvation and the potential for IL-based biomass refinery are also highlighted. [ABSTRACT FROM AUTHOR]

Finding a technological approach that eases the production of lignocellulosic bioethanol has long been considered as a great industrial challenge. In the current study a membrane bioreactor (MBR) set-up using integrated permeate channel (IPC) membrane panels was used to simultaneously ferment pentose and hexose sugars to ethanol in continuous fermentation of high suspended solid wheat straw hydrolysate. The MBR was optimized to flawlessly operated at high SS concentrations of up to 20% without any significant changes in the permeate flux and transmembrane pressure. By the help of the retained high cell concentration, the yeast cells were capable of tolerating and detoxifying the inhibitory medium and succeeded to co-consume all glucose and up to 83% of xylose in a continuous fermentation mode leading to up to 83% of the theoretical ethanol yield. [ABSTRACT FROM AUTHOR]

This study examined the white rot fungus I. obliquus on the degradation of three types of straw biomass and the production of extracellular lignocellulolytic enzymes under submerged fermentation. The fungus process resulted in a highest lignin loss of 72%, 39%, and 47% in wheat straw, rice straw, and corn stover within 12 days, respectively. In merely two days, the fungus selectively degraded wheat straw lignin by 37%, with only limited cellulose degradation (13%). Fourier transform infrared spectroscopy revealed that the fungus most effectively degraded the wheat straw lignin and rice straw crystalline cellulose. Scanning electronic microscopy showed the most pronounced structural changes in wheat straw. High activities of manganese peroxidase (159.0 U/mL) and lignin peroxidase (123.4 U/mL) were observed in wheat straw culture on Day 2 and 4, respectively. Rice straw was the best substrate to induce the production of cellulase and xylanase. [ABSTRACT FROM AUTHOR]

This work focused on the anaerobic digestion performance of pulp and paper mill sludge (PPMS) pretreated with the microbial consortium OEM1, and exposing the mechanism of performance variations as well. It was found that the methane yield was increased 1.4-fold by pretreating feedstocks with the active OEM1, and the maximum methane yield of 429.19 mL/gVS was noted. Moreover, an appropriate pH range of 6.1–7.5 was found in this digester, and no VFA inhibition was observed. A higher level of stability was also detected in this system based on the analysis of ORP, alkalinity and VFA/TA ratio. Also, a higher lignin decomposition rate was determined in the coupled pretreatment - AD process with the active OEM1 addition, and a 5-fold increase of AOX degradation efficiency was found in the pretreatment stage. Hence, a brighter future of developing OEM1 pretreatment for PPMS before AD could be predicted based on the capabilities of selective delignification and effective AOX degradation. [ABSTRACT FROM AUTHOR]

Cellulosic ethanol production relies on the biochemical (enzymatic) conversion of lignocellulose to fermentable sugars and ultimately to bioethanol. However, the cost of lignocellulolytic enzymes is a limiting factor in the commercialisation of this technology. This therefore necessitates the optimisation of lignocellulolytic enzyme cocktails through the elucidation of synergistic interactions between enzymes so as to improve lignocellulose hydrolysis and also lower protein loadings in these reactions. However, many factors affect the synergism that occurs between these lignocellulolytic enzymes, such as enzyme ratios, substrate characteristics, substrate loadings, enzyme loadings and time. This review examines the effect of time on the synergistic dynamics between lignocellulolytic enzymes during the hydrolysis of both complex (true) lignocellulosic substrates and model substrates. The effect of sequential and simultaneous application of the lignocellulolytic enzymes on the synergistic dynamics during the hydrolysis of these substrates is also explored in this review. Finally, approaches are further proposed for efficient and synergistic hydrolysis of both complex lignocellulosic substrates and model substrates. With respect to the synergistic enzymatic hydrolysis of lignocellulosic biomass, this review exposed knowledge gaps that should be covered in future work in order to fully understand how enzyme synergism works: e.g. elucidating protein to protein interactions that exist between these enzymes in establishing synergy; and the effect of lignocellulose degradation products of one enzyme on the behaviour of the other enzyme and ultimately their synergistic relationship. [ABSTRACT FROM AUTHOR]

In enzymatic hydrolysis, high lignocellulose loadings are required to obtain high sugar titers. However, the high solids loadings limit enzymatic hydrolysis. In this study, to overcome this limitation, the promoting and synergistic effects of the accessory agents of hemicellulase (i.e., Cellic HTec2) and polyethylene glycol (PEG) 8000 were investigated in the enzymatic hydrolysis of hydrothermally pretreated empty fruit bunches (EFBs). After the optimal addition of Cellic HTec2 and PEG, high enzymatic digestion of the pretreated EFBs was achieved owing to their synergistic effects, even at high solids loadings. For example, the enzymatic digestibility of pretreated EFBs at a 21.7% (w/v) solids loading with 10 FPU of Cellic CTec2/g glucan reached 72.5% when 2.7 mg of Cellic HTec2/g glucan and 62.5 mg of PEG/g glucan were used as the accessory agents. These results suggested that the optimal addition of accessory agents is effective for the enhanced hydrolysis of lignocellulose using even a commercial cellulase preparation. [ABSTRACT FROM AUTHOR]

Natural cellulose fibers with properties suitable for textile and other applications have been extracted from the outer layer of Ricinus communis (castor plant) stems. Castor plants are cultivated mainly for their oil seeds but are also found to grow extensively as weeds in marshy and polluted waters. The plant grows up to 40 feet in length with minimum requirement of natural resources. Up to 5–10 times the weight of the oil seeds are left as residue which is generally burnt or buried in the ground. In this research, we studied the potential of using castor plant residues as a source for natural cellulose fibers. Fibers were extracted using a simple alkaline approach and characterized for their morphology, physical structure and tensile properties. Polypropylene was reinforced with castor fibers and made into composites. About 25% of the stem could be obtained as fibers with properties similar to that of fibers from other lignocellulosic plant residues. Individual fibers were fibrillar and exhibited convolutions similar to those seen in cotton. Elongation of the fibers at 5% was higher than common bast fibers jute and flax and the strength at 2.7 g/den (350 MPa) was similar to that of jute but lower than that of cotton. Castor fibers have the properties to be processable as textile fibers and were also found to be suitable as reinforcement for composites. [ABSTRACT FROM AUTHOR]