Pressure Indicator Composite Films via Compressive Deformation of a Translucent Matrix Containing a Contrasting Filler.

A neglected mechanism for pressure-responsive color change is demonstrated using cellulose acetate composites prepared by direct (solvent) immersion annealing (DIA), with different loadings of activated charcoal filler. Namely, compressive plastic deformation of the translucent cellulose acetate leads to a decrease in the optical path length and a concomitant increase in the visibility of the opaque contrasting filler. Composites bearing 1-7 wt% activated charcoal exhibited a linear relationship between applied pressure and resulting pressure mark brightness in the range of 12-56 MPa. Comparison of pressure mark patterns with cross-sectional scanning electron microscopy (SEM) supports the importance of the porous morphology arising from DIA for the tuning of the pressure indicator sensitivity. A simple ball drop test is used to illustrate the robustness and utility of these indicators in optical impact assessment.

Multifaced application of AFEX-pretreated biomass in producing second-generation biofuels, ruminant animal feed, and value-added bioproducts.

Lignocellulosic biomass holds a crucial position in the prospective bio-based economy, serving as a sustainable and renewable source for a variety of bio-based products. These products play a vital role in displacing fossil fuels and contributing to environmental well-being. However, the inherent recalcitrance of biomass poses a significant obstacle to the efficient access of sugar polymers. Consequently, the bioconversion of lignocellulosic biomass into fermentable sugars remains a prominent challenge in biorefinery processes to produce biofuels and biochemicals. In addressing these challenges, extensive efforts have been dedicated to mitigating biomass recalcitrance through diverse pretreatment methods. One noteworthy process is Ammonia Fiber Expansion (AFEX) pretreatment, characterized by its dry-to-dry nature and minimal water usage. The volatile ammonia, acting as a catalyst in the process, is recyclable. AFEX contributes to cleaning biomass ester linkages and facilitating the opening of cell wall structures, enhancing enzyme accessibility and leading to a fivefold increase in sugar conversion compared to untreated biomass. Over the last decade, AFEX has demonstrated substantial success in augmenting the efficiency of biomass conversion processes. This success has unlocked the potential for sustainable and economically viable biorefineries. This paper offers a comprehensive review of studies focusing on the utilization of AFEX-pretreated biomass in the production of second-generation biofuels, ruminant feed, and additional value-added bioproducts like enzymes, lipids, proteins, and mushrooms. It delves into the details of the AFEX pretreatment process at both laboratory and pilot scales, elucidates the mechanism of action, and underscores the role of AFEX in the biorefinery for developing biofuels and bioproducts, and nutritious ruminant animal feed production. While highlighting the strides made, the paper also addresses current challenges in the commercialization of AFEX pretreatment within biorefineries. Furthermore, it outlines critical considerations that must be addressed to overcome these challenges, ensuring the continued progress and widespread adoption of AFEX in advancing sustainable and economically viable bio-based industries.

Arabinose as an overlooked sugar for microbial bioproduction of chemical building blocks.

The circular economy is anticipated to bring a disruptive transformation in manufacturing technologies. Robust and industrial scalable microbial strains that can simultaneously assimilate and valorize multiple carbon substrates are highly desirable, as waste bioresources contain substantial amounts of renewable and fermentable carbon, which is diverse. Lignocellulosic biomass (LCB) is identified as an inexhaustible and alternative resource to reduce global dependence on oil. Glucose, xylose, and arabinose are the major monomeric sugars in LCB. However, primary research has focused on the use of glucose. On the other hand, the valorization of pentose sugars, xylose, and arabinose, has been mainly overlooked, despite possible assimilation by vast microbial communities. The present review highlights the research efforts that have explicitly proven the suitability of arabinose as the starting feedstock for producing various chemical building blocks via biological routes. It begins by analyzing the availability of various arabinose-rich biorenewable sources that can serve as potential feedstocks for biorefineries. The subsequent section outlines the current understanding of arabinose metabolism, biochemical routes prevalent in prokaryotic and eukaryotic systems, and possible products that can be derived from this sugar. Further, currently, exemplar products from arabinose, including arabitol, 2,3-butanediol, 1,2,3-butanetriol, ethanol, lactic acid, and xylitol are discussed, which have been produced by native and non-native microbial strains using metabolic engineering and genome editing tools. The final section deals with the challenges and obstacles associated with arabinose-based production, followed by concluding remarks and prospects.

Corrigendum: Microbiome variation across populations of desert halophyte Zygophyllum qatarensis.

[This corrects the article DOI: 10.3389/fpls.2022.841217.].

Multifaceted production strategies and applications of glucosamine: a comprehensive review.

Glucosamine (GlcN) and its derivatives are in high demand and used in various applications such as food, a precursor for the biochemical synthesis of fuels and chemicals, drug delivery, cosmetics, and supplements. The vast number of applications attributed to GlcN has raised its demand, and there is a growing emphasis on developing production methods that are sustainable and economical. Several: physical, chemical, enzymatic, microbial fermentation, recombinant processing methods, and their combinations have been reported to produce GlcN from chitin and chitosan available from different sources, such as animals, plants, and fungi. In addition, genetic manipulation of certain organisms has significantly improved the quality and yield of GlcN compared to conventional processing methods. This review will summarize the chitin and chitosan-degrading enzymes found in various organisms and the expression systems that are widely used to produce GlcN. Furthermore, new developments and methods, including genetic and metabolic engineering of Escherichia coli and Bacillus subtilis to produce high titers of GlcN and GlcNAc will be reviewed. Moreover, other sources of glucosamine production viz. starch and inorganic ammonia will also be discussed. Finally, the conversion of GlcN to fuels and chemicals using catalytic and biochemical conversion will be discussed.

Thermophilic Geobacillus WSUCF1 Secretome for Saccharification of Ammonia Fiber Expansion and Extractive Ammonia Pretreated Corn Stover.

A thermophilic Geobacillus bacterial strain, WSUCF1 contains different carbohydrate-active enzymes (CAZymes) capable of hydrolyzing hemicellulose in lignocellulosic biomass. We used proteomic, genomic, and bioinformatic tools, and genomic data to analyze the relative abundance of cellulolytic, hemicellulolytic, and lignin modifying enzymes present in the secretomes. Results showed that CAZyme profiles of secretomes varied based on the substrate type and complexity, composition, and pretreatment conditions. The enzyme activity of secretomes also changed depending on the substrate used. The secretomes were used in combination with commercial and purified enzymes to carry out saccharification of ammonia fiber expansion (AFEX)-pretreated corn stover and extractive ammonia (EA)-pretreated corn stover. When WSUCF1 bacterial secretome produced at different conditions was combined with a small percentage of commercial enzymes, we observed efficient saccharification of EA-CS, and the results were comparable to using a commercial enzyme cocktail (87% glucan and 70% xylan conversion). It also opens the possibility of producing CAZymes in a biorefinery using inexpensive substrates, such as AFEX-pretreated corn stover and Avicel, and eliminates expensive enzyme processing steps that are used in enzyme manufacturing. Implementing in-house enzyme production is expected to significantly reduce the cost of enzymes and biofuel processing cost.

Microbiome Variation Across Populations of Desert Halophyte Zygophyllum qatarensis.

Microbial symbionts play a significant role in plant health and stress tolerance. However, few studies exist that address rare species of core-microbiome function during abiotic stress. In the current study, we compared the microbiome composition of succulent dwarf shrub halophyte Zygophyllum qatarensis Hadidi across desert populations. The results showed that rhizospheric and endosphere microbiome greatly varied due to soil texture (sandy and gravel). No specific bacterial amplicon sequence variants were observed in the core-microbiome of bulk soil and rhizosphere, however, bacterial genus Alcaligenes and fungal genus Acidea were abundantly distributed across root and shoot endospheres. We also analyzed major nutrients such as silicon (Si), magnesium, and calcium across different soil textures and Z. qatarensis populations. The results showed that the rhizosphere and root parts had significantly higher Si content than the bulk soil and shoot parts. The microbiome variation can be attributed to markedly higher Si - suggesting that selective microbes are contributing to the translocation of soluble Si to root. In conclusion, low core-microbiome species abundance might be due to the harsh growing conditions in the desert - making Z. qatarensis highly selective to associate with microbial communities. Utilizing rare microbial players from plant microbiomes may be vital for increasing crop stress tolerance and productivity during stresses.

Sustainable Biocomposites for Structural Applications with Environmental Affinity.

In this work, we report a facile preparation of biocomposites using a chitosan matrix that is reinforced with morphed graphene in amounts from 1 to 5 wt % C. The composites are processed by milling and conventional sintering. The morphed graphene additions show clear improvements in mechanical properties, having a direct correlation with temperature in particular for 180 °C. Higher temperatures are detrimental to chitosan and the properties drop because chitosan degrades. Mechanical properties in the composite such as yield strength and compressive strength increase between 40 and 50% with respect to the pure chitosan samples. The Young's modulus presents a drop of approximately 10%, but the fracture toughness increases up to 3.5 fold. The properties of our sustainable composites are comparable to those seen in polymers such as polyethylene, polypropylene, nylon, and poly(methyl methacrylate), among other commodity or single use plastics. The enhancement in the mechanical properties is attributed to the morphed graphene embedded chitosan matrix that generates a network of intergranular "anchors" that hold the chitosan crystals in place, preventing failure. The composites can be molded into near-net-shape products, machined, or shaped using various methods including laser lithography. These studies demonstrate the feasibility of fabricating biocomposites with different architectures and sizes for disposable structural components. Both chitosan and the composites are compostable and biodegradable with the potential to sustain plant growth when discarded. In addition, morphed graphene and chitosan are produced from byproducts or waste, which may result in a negative carbon footprint on the environment.

Understanding the structure and composition of recalcitrant oligosaccharides in hydrolysate using high-throughput biotin-based glycome profiling and mass spectrometry.

Novel Immunological and Mass Spectrometry Methods for Comprehensive Analysis of Recalcitrant Oligosaccharides in AFEX Pretreated Corn Stover. Lignocellulosic biomass is a sustainable alternative to fossil fuel and is extensively used for developing bio-based technologies to produce products such as food, feed, fuel, and chemicals. The key to these technologies is to develop cost competitive processes to convert complex carbohydrates present in plant cell wall to simple sugars such as glucose, xylose, and arabinose. Since lignocellulosic biomass is highly recalcitrant, it must undergo a combination of thermochemical treatment such as Ammonia Fiber Expansion (AFEX), dilute acid (DA), Ionic Liquid (IL) and biological treatment such as enzyme hydrolysis and microbial fermentation to produce desired products. However, when using commercial fungal enzymes during hydrolysis, only 75-85% of the soluble sugars generated are monomeric sugars, while the remaining 15-25% are soluble recalcitrant oligosaccharides that cannot be easily utilized by microorganisms. Previously, we successfully separated and purified the soluble recalcitrant oligosaccharides using a combination of charcoal and celite-based separation followed by size exclusion chromatography and studies their inhibitory properties on enzymes. We discovered that the oligosaccharides with higher degree of polymerization (DP) containing methylated uronic acid substitutions were more recalcitrant towards commercial enzyme mixtures than lower DP and neutral oligosaccharides. Here, we report the use of several complementary techniques that include glycome profiling using plant biomass glycan specific monoclonal antibodies (mAbs) to characterize sugar linkages in plant cell walls and enzymatic hydrolysate, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) using structurally-informative diagnostic peaks offered by negative ion post-secondary decay spectra, gas chromatography followed by mass spectrometry (GC-MS) to characterize oligosaccharide sugar linkages with and without derivatization. Since oligosaccharides (DP 4-20) are small, it is challenging to mobilize these molecules for mAbs binding and characterization. To overcome this problem, we have applied a new biotin-coupling based oligosaccharide immobilization method that successfully tagged most of the low DP soluble oligosaccharides on to a micro-plate surface followed by specific linkage analysis using mAbs in a high-throughput system. This new approach will help develop more advanced versions of future high throughput glycome profiling methods that can be used to separate and characterize oligosaccharides present in biomarkers for diagnostic applications.

Challenges and opportunities in producing high-quality edible mushrooms from lignocellulosic biomass in a small scale.

Mushrooms are high-value products that can be produced from lignocellulosic biomass. Mushrooms are the fruiting body of fungi and are domestically cultivated using lignocellulosic biomass obtained from agricultural byproducts and woody biomass. A handful of edible mushroom species are commercially cultivated at small, medium, and large scales for culinary and medicinal use. Details about different lignocellulosic biomass and their composition that are commonly used to produce mushrooms are outlined in this review. In addition, discussions on four major processing steps (i) producing solid and liquid spawn, (ii) conventional and mechanized processing lignocellulosic biomass substrates to produce mushroom beds, (iii) maintaining growth conditions in climate-controlled rooms, and (iv) energy requirements and managements to produce mushrooms are also provided. The new processing methods and technology outlined in this review may allow mushrooms to be economically and sustainably produced at a small scale to satisfy the growing food needs and create rural jobs. KEY POINTS: • Some of the challenges faced by small-scale mushroom growers are presented. This review is expected to stimulate more research to address the challenges.

Chemoenzymatic production of chitooligosaccharides employing ionic liquids and Thermomyces lanuginosus chitinase.

The aim of this work was to study a two-step chemoenzymatic method for production of short chain chitooligosaccharides. Chitin was chemically pretreated using sulphuric acid, sodium hydroxide and two different ionic liquids, 1-Ethyl-3-methylimidazolium bromide and Trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate under mild processing conditions. Pretreated chitin was further hydrolyzed employing purified chitinase from Thermomyces lanuginosus ITCC 8895. Trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate treated chitin appeared amorphous and resulted in generation of 1.10 ± 0.89 mg ml-1 of (GlcNAc)2 and 1.07 ± 0.92 mg ml-1 of (GlcNAc)3. Further derivation of optimum conditions through two-factor-9 run experiments resulted in to 1.5 and 1.3 fold increments in (GlcNAc)2 and (GlcNAc)3 production, respectively. 0.1 g of both (GlcNAc)2 and (GlcNAc)3 has been purified from the Trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate pretreated chitin (1 g) employing cation exchange chromatography. The present study will lay the foundation for development of a green sustainable solution for cost effective upcycling of coastal residual resources to chito-bioactives.

Strategies to improve solid state anaerobic bioconversion of lignocellulosic biomass: an overview.

Solid state anaerobic digestion (SSAD) of lignocellulosic biomass may be attractive solution for its valorisation. Compared to liquid state anaerobic digestion (LSAD), SSAD can handle higher organic loading rates (OLR), requires a less water and smaller reactor volume. It may require lower energy demand for heating or mixing and has higher volumetric methane productivity. Besides numerous benefits of SSAD processes and progress in system design, there are still obstacles, which need to be overcome for its successful implementations. This review aims to compile the recent trends in enhancing the bioconversion of agricultural stubbles in SSAD. Several pretreatment procedures used to breaking lignin and cellulose complex, method to overcome carbon to nitrogen ratio imbalance, use of carbon-based conducting materials to enhance Volatile Fatty Acids (VFA) conversion and additives for achieving nutrient balance will be discussed in this review. Leachate recirculation and its impacts on SSAD of agricultural stubbles are also discussed.

A New Method to Overcome Carboxyamide Formation During AFEX Pretreatment of Lignocellulosic Biomass.

Lignin-carbohydrate complexes (LCCs) in the plant cell wall are responsible for providing resistance against biomass-degrading enzymes produced by microorganisms. Four major types of lignin-carbohydrate bonds are reported in the literature, namely, benzyl ethers, benzyl esters, phenyl glycosides, and acetyl ester linkages. Ester's linkages in the plant cell wall are labile to alkaline pretreatments, such as ammonia fiber expansion (AFEX), which uses liquid or gaseous ammonia to cleave those linkages in the plant cell wall and reduce biomass recalcitrance. Two competing reactions, notably hydrolysis and ammonolysis, take place during AFEX pretreatment process, producing different aliphatic and aromatic acids, as well as their amide counterparts. AFEX pretreated grasses and agricultural residues are known to increase conversion of biomass to sugars by four- to five-fold when subjected to commercial enzyme hydrolysis, yielding a sustainable feedstock for producing biofuels, biomaterials, and animal feed. Animal feed trials on dairy cows have demonstrated a 27% increase in milk production when compared to a control feedstock. However, the presence of carboxamides in feedstocks could promote neurotoxicity in animals if consumed beyond a certain concentration. Thus, there is the need to overcome regulatory hurdles associated with commercializing AFEX pretreated biomass as animal feed in the United States. This manuscript demonstrates a modified pretreatment for increasing the digestibility of industrial byproducts such as Brewer's spent grains (BSG) and high-fiber meal (HFM) produced from BSG and dry distillers grains with soluble (DDGS), while avoiding the production of carboxamides. The three industrial byproducts were first treated with calculated amounts of alkali such as NaOH, Ca(OH)2, or KOH followed by AFEX pretreatment. We found that 4% alkali was able to de-esterify BSG and DDGS more efficiently than using 2% alkali at both 10 and 20% solids loading. AFEX pretreatment of de-esterified BSG, HFM, and DDGS produced twofold higher glucan conversion than respective untreated biomass. This new discovery can help overcome potential regulatory issues associated with the presence of carboxamides in ammonia-pretreated animal feeds and is expected to benefit several farmers around the world.

Natural products as home-based prophylactic and symptom management agents in the setting of COVID-19.

Coronavirus disease (COVID-19) caused by the novel coronavirus (SARS-CoV-2) has rapidly spread across the globe affecting 213 countries or territories with greater than six million confirmed cases and about 0.37 million deaths, with World Health Organization categorizing it as a pandemic. Infected patients present with fever, cough, shortness of breath, and critical cases show acute respiratory infection and multiple organ failure. Likelihood of these severe indications is further enhanced by age as well as underlying comorbidities such as diabetes, cardiovascular, or thoracic problems, as well as due to an immunocompromised state. Currently, curative drugs or vaccines are lacking, and the standard of care is limited to symptom management. Natural products like ginger, turmeric, garlic, onion, cinnamon, lemon, neem, basil, and black pepper have been scientifically proven to have therapeutic benefits against acute respiratory tract infections including pulmonary fibrosis, diffuse alveolar damage, pneumonia, and acute respiratory distress syndrome, as well as associated septic shock, lung and kidney injury, all of which are symptoms associated with COVID-19 infection. This review highlights the potential of these natural products to serve as home-based, inexpensive, easily accessible, prophylactic agents against COVID-19.

Ammonia Fiber Expansion (AFEX) Pretreatment of Lignocellulosic Biomass.

Lignocellulosic materials are plant-derived feedstocks, such as crop residues (e.g., corn stover, rice straw, and sugar cane bagasse) and purpose-grown energy crops (e.g., miscanthus, and switchgrass) that are available in large quantities to produce biofuels, biochemicals, and animal feed. Plant polysaccharides (i.e., cellulose, hemicellulose, and pectin) embedded within cell walls are highly recalcitrant towards conversion into useful products. Ammonia fiber expansion (AFEX) is a thermochemical pretreatment that increases accessibility of polysaccharides to enzymes for hydrolysis into fermentable sugars. These released sugars can be converted into fuels and chemicals in a biorefinery. Here, we describe a laboratory-scale batch AFEX process to produce pretreated biomass on the gram-scale without any ammonia recycling. The laboratory-scale process can be used to identify optimal pretreatment conditions (e.g., ammonia loading, water loading, biomass loading, temperature, pressure, residence time, etc.) and generates sufficient quantities of pretreated samples for detailed physicochemical characterization and enzymatic/microbial analysis. The yield of fermentable sugars from enzymatic hydrolysis of corn stover pretreated using the laboratory-scale AFEX process is comparable to pilot-scale AFEX process under similar pretreatment conditions. This paper is intended to provide a detailed standard operating procedure for the safe and consistent operation of laboratory-scale reactors for performing AFEX pretreatment of lignocellulosic biomass.

Discovery and Expression of Thermostable LPMOs from Thermophilic Fungi for Producing Efficient Lignocellulolytic Enzyme Cocktails.

In this study, two novel thermostable lytic polysaccharide monooxygenases (LPMOs) were cloned from thermophilic fungus Scytalidium thermophilum (PMO9D_SCYTH) and Malbranchea cinnamomea (PMO9D_MALCI) and expressed in the methylotrophic yeast Pichia pastoris X33. The purified PMO9D_SCYTH was active at 60 °C (t1/2 = 60.58 h, pH 7.0), whereas, PMO9D_MALCI was optimally active at 50 °C (t1/2 = 144 h, pH 7.0). The respective catalytic efficiency (kcat/Km) of PMO9D_SCYTH and PMO9D_MALCI determined against avicel in presence of H2O2 was (6.58 × 10-3 and 1.79 × 10-3 mg-1 ml min-1) and carboxy-methylcellulose (CMC) (1.52 × 10-1 and 2.62 × 10-2 mg-1 ml min-1). The HRMS analysis of products obtained after hydrolysis of avicel and CMC showed the presence of both C1 and C4 oxidized oligosaccharides, in addition to phylogenetic tree constructed with other characterized type 1 and 3 LPMOs demonstrated that both LPMOs belongs to type-3 family of AA9s. The release of sugars during saccharification of acid/alkali pretreated sugarcane bagasse and rice straw was enhanced upon replacing one part of commercial enzyme Cellic CTec2 with these LPMOs.

Microbial Lipid Alternatives to Plant Lipids.

Lipids are in high demand in food production, nutritional supplements, detergents, lubricants, and biofuels. Different oil seeds produced from plants are conventionally extracted to yield lipids. With increasing population and reduced availability of cultivable land, conventional methods of producing lipids alone will not satisfy increasing demand. Lipids produced using different microbial sources are considered as sustainable alternative to plant derived lipids. Various microorganisms belonging to the genera of algae, bacteria, yeast, fungi, or marine-derived microorganisms such as thraustochytrids possess the ability to accumulate lipids in their cells. A variety of microbial production technologies are being used to cultivate these organisms under specific conditions using agricultural residues as carbon source to be cost competitive with plant derived lipids. Microbial oils, also known as single cell oils, have many advantages when compared with plant derived lipids, such as shorter life cycle, less labor required, season and climate independence, no use of arable land and ease of scale-up. In this chapter we compare the lipids derived from plants and different microorganisms. We also highlight various analytical techniques that are being used to characterize the lipids produced in oleaginous organisms and their applications in various processes.

Biological treatment of lignocellulosic biomass by Chaetomium globosporum: Process derivation and improved biogas production.

Chaetomium globosporum was isolated from aeolian soil samples collected from semi-arid locations in the state of Rajasthan, India. The efficiency of fungal strain for biological treatment of biomass to improve biogas yield was screened by estimating laccase enzyme activity under submerged fermentation system. Further, lignocellulosic biomass(s) wheat and pearl millet straw were subjected to biological treatment and subsequent increase in release of reducing sugar as compared to untreated straw was determined. Optimization of biological treatment conditions was accomplished by employing response surface methodology with Box Behnken design of experiments. Impact of three parameters (temperature, residence time, moisture content) was analyzed using three severity levels on output response of biological treatment in terms of released reducing sugar (g/L). Observed values were well fitted with second order polynomial equation (R2 = 0.91) and predicted outcomes were in agreement with experimental results. Optimized treatment conditions were: 36 °C, 31 days residence time and 81% moisture. A 2.9 fold increase in reducing sugar was released when substrates were treated under these conditions. Our research findings emphasize importance of optimizing biological treatment conditions to achieve high biogas yield when using wheat and pearl millet straw as feedstocks and similar treatment could be carried out for other lignocellulosic feedstocks.

Incorporating anaerobic co-digestion of steam exploded or ammonia fiber expansion pretreated sugarcane residues with manure into a sugarcane-based bioenergy-livestock nexus.

The co-digestion of pretreated sugarcane lignocelluloses with dairy cow manure (DCM) as a bioenergy production and waste management strategy, for intensive livestock farms located in sugarcane regions, was investigated. Ammonia fiber expansion (AFEX) increased the nitrogen content and accelerated the biodegradability of sugarcane bagasse (SCB) and cane leaf matter (CLM) through the cleavage of lignin carbohydrate crosslinks, resulting in the highest specific methane yields (292-299 L CH4/kg VSadded), biogas methane content (57-59% v/v) and biodegradation rates, with or without co-digestion with DCM. To obtain comparable methane yields, untreated and steam exploded (StEx) SCB and CLM had to be co-digested with DCM, at mass ratios providing initial C/N ratios in the range of 18 to 35. Co-digestion with DCM improved the nutrient content of the solid digestates, providing digestates that could be used as biofertilizer to replace CLM that is removed from sugarcane fields during green harvesting.

Correction to: 'The effect of alkali-soluble lignin on purified core cellulase and hemicellulase activities during hydrolysis of extractive ammonia-pretreated lignocellulosic biomass'.

[This corrects the article DOI: 10.1098/rsos.171529.].