Cellulosic Biomass Research Articles

Dynamic Modeling of Bacterial Cellulose Production Using Combined Substrate- and Biomass-Dependent Kinetics

In this work, kinetic models are assessed to describe bacterial cellulose (BC) production, substrate consumption, and biomass growth by K. xylinus in a batch-stirred tank bioreactor, under 700 rpm and 500 rpm agitation rates. The kinetic models commonly used for Acetobacter or Gluconacetobacter were fitted to published data and compared using the Akaike Information Criterion (AIC). A stepwise fitting procedure was proposed for model selection to reduce computation effort, including a first calibration in which only the biomass and substrate were simulated, a selection of the three most effective models in terms of AIC, and a calibration of the three selected models with the simulation of biomass, substrate, and product. Also, an uncoupled product equation involving a modified Monod substrate function is proposed for a 500 rpm agitation rate, leading to an improved prediction of BC productivity. The M2c and M1c models were the most efficient for biomass growth and substrate consumption for the combined AIC, under 700 rpm and 500 rpm agitation rates, respectively. The average coefficients of determination for biomass, substrate, and product predictions were 0.981, 0.994, and 0.946 for the 700 rpm agitation rate, and 0.984, 0.991, and 0.847 for the 500 rpm agitation rate. It is shown that the prediction of BC productivity is improved through the proposed substrate function, whereas the computation effort is reduced through the proposed model fitting procedure.

Metabolic Engineering of Komagataella phaffii for Xylose Utilization from Cellulosic Biomass

Cellulosic biomass hydrolysates are rich in glucose and xylose, but most microorganisms, including Komagataella phaffii, are unable to utilize xylose effectively. To address this limitation, we engineered a K. phaffii strain optimized for xylose metabolism through the xylose oxidoreductase pathway and promoter optimization. A promoter library with varying strengths was used to fine-tune the expression levels of the XYL1, XYL2, and XYL3 genes, resulting in a strain with a strong promoter for XYL2 and weaker promoters for XYL1 and XYL3. This engineered strain exhibited superior growth, achieving 14 g cells/L and a maximal growth rate of 0.4 g cells/L-h in kenaf hydrolysate, outperforming a native strain by 17%. This study is the first to report the introduction of the xylose oxidoreductase pathway into K. phaffii, demonstrating its potential as an industrial platform for producing yeast protein and other products from cellulosic biomass.

Cellulase entrapment in calcium alginate hydrogel beads for improved reusability and hydrolysis of cellulosic biomass

Cellulase entrapment in calcium alginate hydrogel beads for improved reusability and hydrolysis of cellulosic biomass

Engineering Artificial Three-Species Microbial Consortium to Produce High-Power Bioelectricity from Discarded Cellulosic Biomass of Liquor Industry

Engineering Artificial Three-Species Microbial Consortium to Produce High-Power Bioelectricity from Discarded Cellulosic Biomass of Liquor Industry

Microbial Cellulase Production: Current Technologies and Future Prospects

Enzymes are biocatalysts, that facilitate chemical reactions by lowering their activation energy. Among these, cellulase emerges as a significant enzyme, consisting of a triad of components that work in synergy to degrade cellulosic biomass. Its significance is mostly pronounced in agricultural contexts, where there is an abundance of lignocellulosic biomass making it pivotal for utilization and conversion of biomass. Utilizing the biomass as a substrate for cellulase production offers dual advantages. Firstly, it simplifies the enzymatic synthesis process by the utilization of naturally occurring precursors. Secondly, it contributes to cost reduction by leveraging readily available resources thereby making it economically viable. Microbial cellulases, sourced from diverse microbes found globally, can aid in efficient enzymatic production. Advances in fermentation processes, coupled with the application of biotechnological tools, have significant impacts in production scalability and cost-effectiveness. Optimizing production strategies is crucial to meet the increasing demands of industrial applications while ensuring sustainability. Emphasizing the utilization of biomass substrates and harnessing the potential of emerging biotechnological advancements are key aspects of enzyme production. This review shall aim to provide an in-depth exploration of current cellulase production technologies and future prospects. By elucidating the underlying principles of cellulase catalysis and the intricacies of production methodologies.

Unique Fn3-like biosensor in σI/anti-σI factors for regulatory expression of major cellulosomal scaffoldins in Pseudobacteroides cellulosolvens.

Lignocellulolytic clostridia employ multiple pairs of alternative σ/anti-σ (SigI/RsgI) factors to regulate cellulosomal components for substrate-specific degradation of cellulosic biomass. The current model has proposed that RsgIs use a sensor domain to bind specific extracellular lignocellulosic components and activate cognate SigIs to initiate expression of corresponding cellulosomal enzyme genes, while expression of scaffoldins can be initiated by several different SigIs. Pseudobacteroides cellulosolvens contains the most complex known cellulosome system and the highest number of SigI-RsgI regulons yet discovered. However, the function of many RsgI sensor domains and their relationship with the various enzyme types are not fully understood. Here, we report that RsgI4 from P. cellulosolvens employs a C-terminal module that bears distant similarity to the fibronectin type III (Fn3) domain and serves as the sensor domain. Substrate-binding analysis revealed that the Fn3-like domain of RsgI4 represents a novel carbohydrate-binding module (CBM) that binds to a wide range of polysaccharide types. Structure determination further revealed that the Fn3-like domain belongs to the type B group of CBMs with a predicted concave face for substrate binding. Promoter sequence analysis of cellulosomal genes revealed that SigI4 is responsible for cellulosomal regulation of major scaffoldins rather than enzymes, consistent with the broad substrate specificity of the RsgI4 sensor domain. Notably, scaffoldins are invariably required as cellulosome components regardless of the substrate type. These findings suggest that the intricate cellulosome system of P. cellulosolvens comprises a more elaborate regulation mechanism than other bacteria and thus expands the paradigm of cellulosome regulation.

Evaluating the role of feedstock composition and component interactions on biomass gasification

Biomass gasification offers a solution to waste concerns while generating clean energy. This study examines the gasification of pine sawdust (PS), used ground coffee (UGC), and wheat straw (WS) under identical conditions. The compositions of the biomass samples are determined, and the gasification of individual components (hemicellulose, cellulose, and lignin) are conducted to understand the process’ dependency on the biomass characteristics. The results suggest cellulose and cellulose-rich biomass (PS) produces more tar and less hydrogen than lignin and lignin-rich biomass (UGC and WS). High lignin and hemicellulose content leave more char. Gasification of PS, UGC, and WS yields 12.7, 15.7, and 17.2 vol% hydrogen, respectively. Additionally, cellulose, hemicellulose, and lignin gasification yield 10.5, 22.1, and 30.4 vol% hydrogen, respectively. Comparing experimental and theoretical values for the three biomass samples reveals significant differences due to component interactions. Thermogravimetry analysis (TGA) indicates significant degradation interactions between hemicellulose-lignin, cellulose-hemicellulose, and cellulose-lignin. It is concluded that high cellulose content biomass shows more predictable results, while high lignin and hemicellulose biomass increases secondary reactions or interactions, exacerbating predictability. These findings assist in estimating gasification performance for better biomass selection.

One-pot catalytic conversion of cellulose biomass to bioethanol at low pressure and temperature conditions: H2O as a self-hydrolytic agent

One-pot catalytic conversion of cellulose biomass to bioethanol at low pressure and temperature conditions: H2O as a self-hydrolytic agent

Strain selection and adaptation of a fungal-yeast-microalgae consortium for sustainable bioethanol production and wastewater treatment from livestock wastewater

This study explores the potential of strain selection and adaptation for developing a fungi-yeast-microalgae consortium capable of integrated bioethanol production and livestock wastewater treatment. We employed a multi-stage approach involving isolation and strain selection/adaptation of these consortiums. The study started with screening some isolated fungi to grow on the cellulosic biomass of the livestock wastewater (saccharification) followed by a fermentation process using yeast for bioethanol production. The results revealed that Penicillium chrysogenum (Cla) and Saccharomyces cerevisiae (Sc) produced a remarkable 99.32 ppm of bioethanol and a concentration of glucose measuring 0.56 mg ml− 1. Following the impact of fungi and yeast, we diluted the livestock wastewater using distilled water and subsequently inoculated Nile River microalgae into the wastewater. The findings demonstrated that Chlorella vulgaris emerged as the dominant species in the microalgal community. Particularly, the growth rate reached its peak at a 5% organic load (0.105385), indicating that this concentration provided the most favorable conditions for the flourishing of microalgae. The results demonstrated the effectiveness of the microalgal treatment in removing the remaining nutrients and organic load, achieving a 92.5% reduction in ammonia, a 94.1% reduction in nitrate, and complete removal of phosphate (100%). The algal treatment also showed remarkable reductions in COD (96.5%) and BOD (96.1%). These findings underscore the potential of fungi, yeast, and Nile River microalgae in the growth and impact on livestock wastewater, with the additional benefit of bioethanol production.Graphical abstract

Cellulose nanomaterial metrology: microscopy measurements.

Cellulose nanomaterials are increasingly used for a wide variety of applications. Adequate characterization of these materials is required for quality control during production, to distinguish between materials synthesized by different methods, by different suppliers or from difference cellulose biomass sources, to facilitate development of applications and for regulatory purposes. Here we review recent microscopy measurements for the three main types of cellulose nanomaterials: cellulose nanocrystals, individual cellulose nanofibrils and cellulose nanofibrils. Atomic force microscopy and both scanning and transmission electron microscopy are covered with a focus on recent studies that have metrological rigor, rather than qualitative investigations. In some cases results are compared to those obtained by other methods that are more likely to see widespread use for routine quality control measurements. Detailed studies that use microscopy to provide insight on fundamental material properties (e.g., chiral properties) are also included. Particle size and morphology are important properties but are challenging to measure for cellulose nanomaterials due to the rod or fibril shaped particles, their propensity to agglomerate and aggregate, their low contrast for electron microscopy and, for cellulose nanofibrils, the complex branched and interconnected structures. Overall, the results show that there are now a number of studies in which attention to metrological detail has resulted in measurements that allow one to compare and distinguish between different materials, although there are still examples for which it is not possible to draw conclusions on size differences. The use of detailed microscopy protocols that yield accurate and reliable results will be beneficial in material production and addressing regulatory requirements and will allow the validation of other methods that are more amenable to routine measurements.

Silica surface modification using cellulose as a renewable organosilane derived from coconut coir fiber for carbon capture

The properties of silica surface modification for carbon capture were studied, utilizing cellulose-amine as a modification agent derived from dissolved coconut coir fiber. To form bonds with NH2 functional groups through amination processes, cellulosic biomass waste is utilized, which is analogous to replacing alkoxy ligands. The dual-function mixture reagents dimethyl sulfoxide (DMSO) and ammonium hydroxide (NH4OH) were employed in the same system as the amine sources and solvents. Waterglass is used as a source of silica, and the modified particles are formed using a one-step consecutive sol-gel spray drying process used in a direct condensation route. Changes in the concentration of sodium lauryl sulfate (SLS) were examined to determine how they affected the essential parameters of the particles. The template is removed during particle formation without further physical or chemical processing. The particle morphology changed from donut-shaped to spherical after SLS application, as evidenced by the increase in SLS concentration. This also shows that the increase in the particle surface area is directly influenced by the increase in the formation of new pore structures with increasing SLS concentration. Through this mechanism, it is possible to extend the pore size distribution to the meso-macropore regime and initiate the formation of new mesopores. This has a direct impact on the capacity to absorb CO2 gas by increasing the cellulose-amine mass fraction that can be grafted to as high as 32.35 %wt. At an operating pressure of 6 bar, a maximum CO2 gas adsorption capacity of 5.32 mmol/g silica was attained by adding SLS 3 CMC to the silica particles. This value is 2.3 times higher than that obtained when using an aminosilane-based modification agent.

Heteropoly Acid‐Based Ionic Liquid Catalyzes Cellulose into Levulinic Acid in a Bi‐Phase Solvent System

AbstractLevulinic acid is an important chemical intermediate, which has many applications in organic synthesis, industry, agriculture, and medicine. In this word, three kinds of heteropoly acid based ionic liquids ([IMPS]H2PW12O40、[PyPS] H2PW12O40 [TEAPS] H2PW12O40) were used to catalyze the one‐pot conversion of cellulose to levulinic acid. [IMPS]H2PW12O40 has the highest catalytic activity due to its strong Hammett acidity (H0). In addition, the effect of biphasic solvent systems on the conversion of cellulose to levulinic acid was also studied. The results showed that the GVL/H2O system could effectively promote the conversion of cellulose and increase the yield of levulinic acid. The yield of levulinic acid could reach 52.6% and the conversion rate of cellulose was 91.2% at 180 °C for 180 min under the GVL/H2O volume ratio of 1:1 with [IMPS]H2PW12O40 as a catalyst at 1 Mpa N2 and cellulose as raw material. And [IMPS]H2PW12O40 can be recycled up to five times without significant performance loss. This study provides a promising method for efficiently converting cellulose and other biomass resources to levulinic acid extraction.

Research and Application of Chemical Sand Control without Blockage in WellBore

Abstract The main sand control methods for oil production wells in a certain Oilfield include mechanical filling sand control, artificial well bore reconstruction with coated sand, and phenolic resin sand control. Mechanical filling for sand control requires the well bore to be intact, with residual pipe columns in the well that cannot meet the testing fluid profile, and subsequent processing often requires major repairs; The construction pressure of artificial well bore is high, and the production of chemical resin sand control is significantly reduced. In order to ensure the consolidation strength, both sand control processes are under displacement operations, and the well bore above the top boundary of the perforated layer is fixed with a plug that needs to be drilled. Research on a new type of chemical sand control technology for well bore without blockage. By using biomass cellulose crystals with smaller particle size and resin in the sand fixing agent combination, the sand particles in the formation are well coated, and condensation reaction occurs to achieve the goal of sand control. The casing will not solidify to create well bore blockage, avoiding later drilling and plugging operations. The construction pressure is low, the damage to the casing is small, and it has a certain degree of selectivity. After sand control, the water content can be reduced by more than 10%. It is suitable for sand control operations in casing damage wells, casing change wells, high inclination wells, and horizontal wells, and can be used for packer construction. As of December 2023, there have been 8 on-site applications with a success rate of 100%, Average water content reduced by 13%, and a cumulative recovery of 2936 tons of oil production. This has safely and efficiently solved the sand control problem in complex well conditions.

Bacterial Cellulose-Derived Sorbents for Cr (VI) Remediation: Adsorption, Elution, and Reuse.

The search for adsorbents that are non-toxic and low cost with a high adsorption capacity and excellent recyclability is a priority to determine the way to reduce the serious environmental impacts caused by the discharge of effluents loaded with heavy metals. Bacterial cellulose (BC) biomass has functional groups such as hydroxyl and carbonyl groups that play a crucial role in making this cellulose so efficient at removing contaminants present in water through cation exchange. This research aims to develop an experimental process for the adsorption, elution, and reuse of bacterial cellulose biomass in treating water contaminated with Cr (VI). SEM images and the kinetics behavior were analyzed with pseudo-first- and pseudo-second-order models together with isothermal analysis after each elution and reuse process. The adsorption behavior was in excellent agreement with the Langmuir model along with its elution and reuse; the adsorption capacity was up to 225 mg/g, adding all the elution processes. This study presents a novel approach to the preparation of biomass capable of retaining Cr (VI) with an excellent adsorption capacity and high stability. This method eliminates the need for chemical agents, which would otherwise be difficult to implement due to their costs. The viability of this approach for the field of industrial wastewater treatment is demonstrated.

Development of fruit peel biomass cellulose and pineapple leaf fibre polyester composite: fatigue, creep, flammability, and thermal conductivity behaviour

Development of fruit peel biomass cellulose and pineapple leaf fibre polyester composite: fatigue, creep, flammability, and thermal conductivity behaviour

Statistical Optimization and Purification of Cellulase Enzyme Production from Trichosporon insectorum

Enzymatic degradation of cellulosic biomass represents the most sustainable and environmentally friendly method for producing liquid biofuel, widely utilized in various commercial processes. While cellulases are predominantly produced by bacteria and fungi, the enzymatic potential of cellulase-producing yeasts remains significantly less explored. In this study, the yeast strain Trichosporon insectorum, isolated from the gut of the coprophagous beetle Gymnopleurus sturmii, was utilized for cellulase production in submerged fermentation. A central composite design was employed to optimize cellulase production, with substrate concentration, temperature, and pH as dependent variables. The highest CMCase activity of 0.71 IU/mL was obtained at 1% substrate concentration, pH 5, and an incubation temperature of 40 °C for 72 h of fermentation using cellulose as a carbon source. For FPase production, the high value was 0.23 IU/mL at 0.5% CMC, pH 6, and an incubation temperature of 40 °C for 72 h. After purification, the enzymes produced by T. insectorum represent 39% of the total proteins. The results of this study offer an alternative strategy for utilizing various carbon sources, both soluble (CMC, carboxymethylcellulose) and insoluble (cellulose), to efficiently produce cellulase for the degradation of lignocellulosic materials. This approach holds promising benefits for sustainable waste management.

Bioderived nanostructure and their functional contribution in immobilization of cellulolytic enzymes for improving biosensing application

Cellulases fall under the biocatalyst and one of industrial enzymes which is highest in demand due to diverse and huge applications. It plays major role in cellulosic bioenergy production achieving biomass hydrolysis for sugar and energy production. Inspite of prime enzyme in demand and key application in cellulosic energy production, this group of enzymes are suffering with lower enzyme activity and poor functional stability which directly influence the poor bioconversion efficiency of cellulosic biomass and bioenergy production. This is one the crucial issue which blocks the suitable commercial implementation of bioenergy at global scale. Therefore, researches in this particular area accelerate and speed in up to improve the functional stability of this enzymes. Immobilization of cellulolytic enzymes on nanomaterials is emerging as one of the very promising approaches in this area and supposed to have sustainable future towards improving the functional stability of cellulase enzymes via nanostructure based immobilization. Due to unique physicochemical properties and mode of origin nanoform, these nanomaterials can be an effective tool to enhance the catalytic stability of the cellulase enzymes. Therefore, the present reviews explore the possibilities of immobilization of nanomaterials as one of the promising tool to improve cellulosic bioenergy production. Additionally, one of the prime focus of the review is also based on the types, methods and mode of immobilization using different nanomaterials and analyzed the existing advantages and disadvantages of the process. Moreover, the work has also been highlighted the existing limitation and the future suggestion to improve the process applicability.

Synthesis and Characterization of Thiol-Ene Networks Derived from Levoglucosenone.

Levoglucosenone (LGO), a renewable compound obtained from cellulose biomass, has been utilized to prepare novel monomers bearing alkene functional groups. These monomer derivatives of LGO were subsequently cured via ultraviolet (UV)-initiated radical thiol-ene "click" chemistry with commercially available multifunctional thiols to obtain colourless, optically transparent cross-linked thermosets. The monomers prepared in this work are unique due to utilising the internal double bond of the LGO ring during polymerization as part of the cross-linked network. The thermal and mechanical properties along with the degradation of thermosets containing both ether and ester linkages within the LGO monomers were studied. These thermosets had tensile strengths of 1.3-3.3 MPa, glass transition temperatures between 23.2 and 27.2 °C, and good thermal stability of up to 300 °C.

Evaluation of reduced graphene oxide from cotton waste as an efficient phenol adsorbent in aqueous media.

The elimination of organic substances, such as phenol, in conventional and biological processes, has been considered a challenge for the petroleum industry. In this work, reduced graphene oxide (rGO), obtained from cellulosic biomass (CB-rGO), as cotton waste, was employed as a phenol adsorbent in an aqueous solution simulating refinery effluent. The CB-rGO was characterized using HRTEM, Raman, XRD, FTIR, BET, and zeta analysis. The behavior of variables such as pH, contact time, temperature, CB-rGO mass, and adsorbate concentration on the characteristics of the adsorption process were continuously investigated. These parameters of the adsorption process were evaluated across a range of adsorbent concentrations from 100 to 300mg/L, pH in the range of 2-11, adsorbent mass 5-25mg, contact time of 0-180min, and temperature of 20-60°C. The adsorption isotherm data were better described by the Freundlich equation compared to the Langmuir and Sips models, despite the small difference in R2 values. Mechanism diffusion was analyzed using the Boyd model and confirmed to be the rate-limiting step in the adsorption process. The endothermic nature of this CB-rGO adsorption process with phenol was confirmed by verifying the thermodynamic data. This successful removal of phenol from synthetic effluents highlights the promising potential of this adsorbent obtained from an industrial residue and being an ecologically more sustainable alternative compared to the synthesis of other materials identified to remove this contaminant.

Characterization of vinyl silane-treated biomass cellulose and banana fiber on reinforced unsaturated polyester composite

Characterization of vinyl silane-treated biomass cellulose and banana fiber on reinforced unsaturated polyester composite