Combined alkali impregnation and poly dimethyl diallyl ammonium chloride-assisted cellulase absorption for high-efficiency pretreatment of wheat straw

doi:10.21203/rs.3.rs-3336088/v1

Download PDF

Research Article

Combined alkali impregnation and poly dimethyl diallyl ammonium chloride-assisted cellulase absorption for high-efficiency pretreatment of wheat straw

https://doi.org/10.21203/rs.3.rs-3336088/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 14 Dec, 2023

Read the published version in Advanced Composites and Hybrid Materials →

You are reading this latest preprint version

Bio-enzyme pretreatment can effectively reduce the chemical resistance of wood fibers, thereby resulting in a reduction in energy consumption during the pulping process. However, both cellulase and cellulose fibers commonly exhibit negative charge used in water, leading to inherent electrostatic repulsion. The present study developed a novel combined pretreatment approach involving alkali impregnation and poly dimethyl diallyl ammonium chloride (PDADMAC)-assisted treatment to enhance the efficiency of cellulase treatment and obtain pulp with superior properties. The results showed that the alkali impregnation effectively destroyed the waxy layer on the surface of wheat straw, enhancing the interaction between subsequent cellulase and wheat straw fibers. The presence of PDADMAC further facilitated cellulase adsorption onto the wheat straw surface. When the PDADMAC dosage was increased to 1.0×10^− 3 g/g wheat straw, the cellulase adsorption rate exhibited a significant increase of 42.28%. Additionally, at cellulase dosages of 10 U/g and 15 U/g, the pulp filtration capacity demonstrated improvements of 35.41% and 16.30%, respectively.

wheat straw

poly dimethyl diallyl ammonium chloride

cellulase

pulping

Renewable lignocellulosic resources, such as wheat straw, are abundant in cellulose content and can serve as valuable raw materials for the pulp and paper industry [1], energy field [2–8], etc. The wheat straw is a plentiful agricultural residue in northern China; however, the majority of it is incinerated and subsequently returned to the fields [9]. The application of wheat straw as pulping material not only reduces environmental pollution but also alleviates the scarcity of the raw materials in the pulp and paper industry [10]. However, the traditional chemical pulping method for wheat straw results in a low pulping yield, a high-level content of silica in the waste liquor, and challenging in chemical recovery [11, 12]. The mechanical pulping method will decrease the physical strength of pulping and has a high energy consumption.

In recent years, the enzyme-assisted pre-treatment methods have been developed to mitigate the chemical resistance of raw materials, reduce energy consumption, and enhance pulp performance [13–20]. The application of cellulase can reduce the production of fine fibers, thereby enhancing the water filtration efficiency of pulp and the physical properties of paper during the papermaking process [21, 22]. Varghese et al. [10] used enzyme pretreatment to improve the efficiency of wheat straw soda-AQ pulping, reduce the consumption of alkali, produce less toxic waste water, and improve paper quality. Wang et al. [23] employed cellulase to diminish the silicon content of wheat straw and disrupt a portion of the silicon layer as well as vascular bundle tissue within the wheat straw. Duan et al. [24] developed a process involving the combination of pulp fractionation and cellulase treatment to improve the molecular weight distribution and reactivity of kraft dissolving pulp.

The enhancement of enzyme processing efficiency has always been a pivotal subject matter. In the scientific literature, numerous studies have presented methodologies to optimize the efficacy of enzymatic treatment. Sun et al. [25]reported that freeze-thaw pretreatment resulted in a loosening of the structure of wheat straw. The occurrence of longitudinal and transverse cracks on the surface, enlargement of pore size, disruption of crystallization zone, and rupture of hydrogen bonds facilitated enzymatic degradation of wheat straw. Zhao et al. [26] demonstrated that THF/H₂O co-solvent pretreatment effectively facilitates lignin removal from straw, thereby exposing cellulose and enhancing the efficiency of enzymatic hydrolysis. Alkali treatment has been regarded as a cost-effective and efficient approach to enhance enzyme treatment, whereby an alkaline solution is employed for the pre-treatment of wheat straw. This facilitates the removal of lignin and uronic acid from hemicellulose, while also eliminating the hydrophobic layer on its surface, thereby optimizing enzymatic accessibility to cellulose [27].

The efficiency of enzyme processing is correlated with the adsorption of cellulase onto cellulose [28–30]. Both cellulose and cellulase components are negatively charged in water, resulting in a certain electrostatic repulsion, which reduces the adsorption of cellulase onto cellulose [31]. The presence of cationic polymer can potentially augment the adsorption efficiency of cellulase and enzyme treatment, owing to the synergistic interaction between cationic and anionic polymers. Wang et al. [31]used cationic polyacrylamide (CPAM) as an additive to improve the treatment efficiency of cellulase, thus improving the quality of broadleaf kraft paper-based dissolved pulp. It was observed that the addition of CPAM resulted in a 20% increase in cellulase adsorption on cellulose compared to its absence. Poly (dimethyl diallyl ammonium chloride) (PDADMAC) is a cationic polyelectrolyte with high charge density that can be used as a conditioning agent for sludge dewatering [32, 33]. The application of PDADMAC, with a molecular weight of 1 kg/mol, exhibits significant efficacy in the treatment of pulp and paper wastewater by achieving a remarkable removal efficiency of 90% for turbidity and effectively eliminating 6 g/L of total suspended solids [34]. Yang et al. [35]employed PDADMAC auxiliary cellulase treatment on pulp, resulting in a 30% increase in the amount of cellulase adsorbed onto cellulose after adding low-molecular-weight PDADMAC. This facilitated mechanical refining and reduced energy consumption and cellulase usage.

The inefficiency of cellulase in degrading the fibers within wheat straw necessitates the development of a green and efficient approach, namely alkali impregnation and PDADMAC-assisted cellulase pretreatment of wheat straw. Firstly, alkali impregnation disrupts the surface structure of wheat straw, degrades certain lignin and pectin, thereby exposing a greater proportion of internal fibers to enhance cellulase contact area. Subsequently, PDADMAC-assisted cellulase treatment was systematically investigated. This combined pretreatment process has the following advantages: 1) improving the treatment efficiency of cellulase and facilitating the subsequent grinding of wheat straw, 2) reducing cellulase consumption and production costs.

2.1. Materials and chemicals

Cellulase was produced by Shandong Longcott Enzyme Preparation Co., Ltd. Wheat straw was sourced from a paper mill in Shandong province. It was carefully selected, cut into uniform lengths of 3–5 cm, thoroughly cleaned, mechanically compressed to remove excess moisture, and finally air dried for subsequent utilization. Fluorescein isothiocyanate and PDADMAC were purchased from Shanghai Maclin Biochemical Co., Ltd.

2.2. Raw materials pretreatment

The wheat straw was initially subjected to alkali treatment in this experiment, followed by its division into two distinct groups. One group underwent cellulase treatment alone, while the other group received PDADMAC-assisted cellulase treatment. Subsequently, both groups were subjected to a two-stage milling process using a high-concentration disc mill to obtain pulp. The resulting paper was obtained through pulping, mediating, and copying stages, with subsequent analysis of its properties.

2.3. Alkali impregnation

A specific quantity of air-dried wheat straw was placed in a hermetically sealed bag. Subsequently, alkaline hot water at 100°C (4% NaOH, liquid ratio of 1:4) was added and thoroughly kneaded to ensure even distribution. The mixture was then immersed in a water bath at 100°C for 20 minutes, followed by neutralizing the wheat straw through washing. For SEM imaging, a frozen and dried portion of the sample was prepared. Surface morphology before and after alkali treatment was examined using a scanning electron microscope (TM4000Plus, Hitachi, Japan).

2.4. Cellulase treatment

The wheat straw was impregnated with a specific amount of alkali and placed in a sealed bag. For the control group (cellulase treatment without PDADMAC), the required amount of cellulase was added, evenly distributed, and then subjected to a 55°C water bath for two hours. In the case of PDADMAC-assisted cellulase treatment, both PDADMAC and cellulase were sequentially added in the required amounts under identical reaction conditions as those used for cellulase alone. After treatment, the wheat straw was washed multiple times to prepare the grinding pulp.

2.5. Determination of Cellulase adsorption

5 g of alkali-treated wheat straw was immersed in 500 g sodium acetate buffer (pH = 4.8), different amounts of PDADMAC were added to the mixture and then stirred at 55 ℃ for 30 min at the speed of 200 rpm. Then cellulase (20 U/g raw material) was added and stirred at 55 ℃ for 120 min at 200 rpm. Then the filtrate sample was separated by 0.22 µm filter membrane filtration. Free cellulase in the filtrate was detected using a BCA protein concentration assay kit. The increased rate of cellulase adsorption was calculated by Eq. (1) below:

Cellulase adsorption increase ration (CAIR) (%) \(\text{=}\frac{\text{(}{\text{W}}_{\text{1}}\text{-}{\text{W}}_{\text{2}}\text{)}}{{\text{W}}_{\text{1}}}\text{×100}\) (1)

where, W₁ is the cellulase content in the supernatant without PDADMAC, and W₂ is the cellulase content in the supernatant with PDADMAC added. The same method was also used to determine the variation in cellulase adsorption situation on wheat straw over time when cellulase was treated alone and when PDADMAC (1.0*10^− 3 g/g) was added.

2.6. Laser confocal scanning microscope (CLSM) analysis

The detection of cellulase was performed using fluorescein isothiocyanate (FITC), following the established protocols [36]. Briefly, a 100 g solution of cellulase (1% concentration, pH = 9) was prepared and supplemented with 1 mg FITC. Unbound FITC was separated using an ultrafiltration tube, and the labeled cellulase probe was stored at 4 ℃ in the dark after shaking for 12 h at 4 ℃.The wheat straw, treated with 2 g of alkali, was immersed in a solution containing 200 g of acetic acid-sodium acetate buffer. Subsequently, it underwent treatment with probe cellulase and probed cellulase combined with PDADMAC (PDADMAC-assisted cellulase treatment). The conditions were: Cellulase of 10 U/g raw materials, PDADMAC of 1×10^− 3 g/g raw materials, 55 ℃, 1 h. The whole process takes place in the dark, and the raw material samples are viewed under a CLSM at 488 nm. The fluorescence was collected between 515 and 540 nm.

2.7. Wheat straw three-dimensional structure

The three-dimensional structure of wheat straw was examined by micro-CT after enzyme treatment. Sample formulation: The wheat straw was cut into 10 mm × 1 mm × 1 mm (Length × Height × Width) and then fixed on the sample stage. The test conditions for Micro-CT were 50 kV supply voltage, 350 µA source current, micro-focus primitive focus mode, 500 ms exposure time, and 300 nm image pixel size.

2.8. Pulp performance analysis

To determine the tearing index, tensile index, and ring compression index of paper, use a paper tearing tester (SLY-1000), a horizontal tensile strength meter (XLW-B), and a ring compression strength tester (TMI). The filtering water of pulp was determined using a DFR-05 water filtering instrument, with 5 g of absolutely dry pulp evacuated into 1000 mL of water and measuring the weight of water filtered from the pulp suspension within 30 s.

3.1. Alkali impregnation and PDADMAC assisted cellulase treatment

A pretreatment method for wheat straw pulping was proposed, which used alkali impregnation and PDADMAC-assisted cellulase to pretreat wheat straw, thereby improving the quality of wheat straw into pulp (Fig. 1). The natural cuticle on the surface of wheat straw will prevent the enzyme from moistening and softening the wheat straw fiber. The pretreatment of wheat straw with alkali impregnation can destroy the cuticle of wheat straw. The cell walls of wheat straw fiber cells are rich in lignin, which typically hinders cellulase treatment [37]. However, alkali impregnation can partially dissolve the lignin [38], thereby enhancing the subsequent efficiency of cellulase treatment.

Both cellulose and cellulase are negatively charged, so there is a certain electrostatic repulsion between them. PDADMAC, a cationic polyelectrolyte with a higher charge, increases the zeta potential of wheat straw, increasing the adsorption of cellulase on cellulose fibers due to favorable electrostatic interactions. In the process of PDADMAC-assisted cellulase pretreatment pulp, the molecular weight of PDADMAC would also affect the adsorption of cellulase on cellulose due to the porous nature of cellulose fibers. Low M_w PDADMAC is easier to interact with pulp fibers through electrostatic interactions or bridging mechanisms than its high M_w counterpart, since more surfaces will be available for low M_w PDADMAC, therefore low M_w PDADMAC was selected in this experiment [35].

3.2. Alkali impregnation

SEM was used to analyze the surface morphology of wheat straw before and after alkali impregnation to determine the treatment effect of alkali impregnation on the surface of wheat straw. The unalkali-impregnated wheat straw is depicted in Fig. 2a(i), a(ii), and a(iii), revealing a smooth stratum corneum on its surface. Its composition is mainly fat, pectin and wax, forming a dense protective layer for the internal fibers[27] [38], which hinders the efficiency of subsequent treatment by cellulase.

The alkali impregnation process results in the destruction of the stratum corneum on the surface of wheat straw, as depicted in Fig. 2b(i), b(ii), and b(iii). Consequently, the internal fibers become gradually exposed, thereby reducing fiber entanglement during pulping. Moreover, this treatment softens and moistens the inner fibers of wheat straw, minimizing fiber damage during pulping. Simultaneously, it enhances cellulose accessibility and improves subsequent cellulase processing efficiency.

3.3. Adsorption of cellulase on wheat straw

The effect of cellulase adsorption on wheat straw after the addition of PDADMAC is shown in Fig. 3. As shown in the Fig. 3a, the CAIR showed a relatively flat trend of improvement when the concentration of PDADMAC was low, and as the concentration of PDADMAC increased, the CAIR showed a rapid increase. When the PDADMAC concentration reached 1.0×10^− 3 g/g wheat straw, the CAIR reached 42.28% and gradually leveled off. This could be attributed to the incomplete coverage of wheat straw surface by PDADMAC at low concentrations; however, with increasing PDADMAC concentration, the exposed fibers on the wheat straw surface were progressively coated, resulting in the attainment of maximum cellulase adsorption.

3.4. Cellulase distribution

Fluorescence confocal laser scanning microscopy (CLSM) is commonly used to observe micron-sized particles or cells. The application of CLSM enables the acquisition of cross-sectional images of pretreated wood particles immersed in fluorescently labeled cellulase solutions, facilitating the observation of specific areas where cellulase exhibits preferential binding to the material [39]. Additionally, CLSM allows for real-time visualization of enzyme systems on both untreated and delignified plant cell walls [40]. In this study, the distribution of cellulase on the wheat straw surface was determined by the CLSM technique. FITC can specifically bind cellulase and has strong fluorescence, so it was used as a probe.

The CLSM results are presented in Fig. 4, illustrating the correlation between fluorescence intensity and cellulase distribution. In Fig. 4a and d, it is evident that cellulase deposition occurs on the surface of wheat straw in both the cellulase treatment alone and PDADMAC-assisted treatment. Specifically, cellulase predominantly localizes within the stomata and crevices of the cuticle on the wheat straw surface. The fluorescence intensity at the surface grain and stomatal locations in Fig. 4d is significantly stronger and more uniform compared to that in Fig. 4a. The average fluorescence intensity, calculated using Image J software for Fig. 4b and e, reveals that the average fluorescence intensity of Fig. 4e is higher than that of Fig. 4b, indicating a greater adsorption of cellulase on the straw surface with PDADMAC-assisted treatment compared to treatment with cellulase alone.

The result suggests that, in the absence of other treatments, a significant portion of the added cellulase remains in solution rather than binding to the fibers due to electrostatic repulsion between them, leading to reduced efficiency in feedstock treatment by cellulase. However, the introduction of cationic PDADMAC alters this scenario by enhancing cellulase adsorption onto the fibers and improving treatment efficiency.

3.5. Three-dimensional structure analysis of wheat straw

The technique of Micro-CT, a non-invasive and non-destructive imaging method [41], employs X-rays to scan the sample without causing any damage, enabling the acquisition of internal structural information and detailed three-dimensional insights within the tested specimen. The internode of wheat straw is a hollow cylinder composed primarily of parenchymatous ground tissue, vascular bundles, and epidermis [42]. The epidermis of wheat straw is typically characterized by a higher degree of cellular density compared to the parenchyma tissue. The inner layer, which exhibits a dense arrangement, primarily consists of vascular cells and vascular tissue. Towards the innermost region, the vascular bundle cells transition into parenchyma cells that possess larger dimensions and a lower level of cellular packing [43].

The three-dimensional structure of wheat straw after enzyme treatment is shown in Fig. 5, where the vascular bundle tissue in the inner part of Fig. 5a is partially degraded, and the overall is still denser. In Fig. 5b, the inner vascular bundle tissue has been significantly degraded, and the vascular bundle tissues on both sides are also in a looser state. Figure 5d shows that the surface protrusions are detached compared to Fig. 5c. This may be attributed to the fact that cellulase primarily targets the fibers within the vascular bundle tissue of wheat straw, with a lesser impact on its surface [23]. With the aid of PDADMAC, the efficiency of cellulase treatment was improved and the internal vascular tissues were degraded to a greater extent.

3.6. Pulp characteristics analysis

The wheat straw is subjected to alkali impregnation as a pretreatment, followed by cellulase treatment, and finally processed into pulp using a high-concentration disc mill. The physical property test results of the pulp-formed paper are shown in Fig. 6 (a). The results of the water filtration test of the pulp are shown in Fig. 7. The conditions were 10 U/g, 15 U/g and 20 U/g cellulase alone and PDADMAC-assisted cellulase treatment, respectively.

The results depicted in Fig. 6 (a) demonstrate that the incorporation of PDADMAC enhances the physical properties of paper formation under equivalent cellulase treatment. This can be attributed to the fact that cellulase enzymatically degrades a portion of the fibrous tissue with cuticle on the surface of wheat straw, resulting in improved wetting ability and fiber softening. Consequently, this reduces fiber damage during milling and ultimately enhances pulp paper strength. With the addition of PDADMAC, the adsorption of cellulase onto wheat straw fibers is enhanced due to favorable electrostatic attraction, thereby enhancing the processing efficiency of cellulase and facilitating thorough wetting and filamentation of wheat straw fibers. Consequently, this leads to improved physical properties of pulp paper. In addition, the tearing index of the pulp finished paper was reduced at 15 U/g cellulase plus PDADMAC treatment instead, probably because the addition of PDADMAC led to more local enzymatic degradation under the condition of higher cellulase dosage, which resulted in more weak links in the fiber structure and reduced the tearing performance of the paper [44].

A comparative analysis of PDADMAC-assisted treatments was also conducted in a similar manner for xylanase and lipase. The findings pertaining to paper properties are illustrated in Fig. 6b and c, wherein the incorporation of PDADMAC exhibited comparable enhancements on the efficacy of both xylanase and lipase treatment. Specifically, lipase effectively eliminates surface wax from wheat straw, thereby facilitating solution penetration and ultimately improving paper performance as well as its inherent properties. Xylanase can enhance the fiber treatment during the pulping process by hydrolyzing some of the hemicellulose in the wheat straw to improve paper properties.

The results of pulp water filtration performance are shown in Fig. 7 (a). The results show the mass of water removed in 30 s from a suspension of the same weight of absolutely dry pulp mixed with 1000 ml of water. The filtered water weight of the pulp was lowest at 10 U/g cellulase alone, with only 336 g in 30 s. The filtered water weight of the pulp was 399 g and 419 g within 30 s under the action of 15 U/g and 20 U/g cellulase alone, respectively. 10 U/g, 15 U/g and 20 U/g cellulase dosage increased the filtered water quality of the pulp suspension to 455 g, 464 g and 465 g in 30 s after the addition of PDADMAC, respectively. The cellulase selectively hydrolyzes the fine fibers in the pulp, resulting in a reduction of the fine fraction on the fiber surface and a relative increase in the long fiber fraction. Additionally, cellulase exhibits flocculating properties towards the fine fraction, thereby enhancing pulp filtration water quality. The incorporation of PDADMAC significantly enhances the treatment efficiency of cellulase, augments its hydrolysis effect on cellulose, and improves the filtration quality of pulp. Additionally, PDADMAC can modify the charge characteristics of fibers, reducing inter-fiber repulsion and promoting fiber flocculation, thereby facilitating water removal. The water filtration performance of PDADMAC-assisted 10 U/g cellulase treatment compared to the PDADMAC-assisted 15 U/g cellulase treatment tested was found to be essentially equivalent, likely attributed to the enhanced efficiency of cellulase treatment resulting in the reformation of long fibers into finer ones. These results show that the addition of PDADMAC improves the processing efficiency of cellulase, reduces the amount of cellulase, and improves the performance of pulp.

The water filtration effect of PDADMAC-assisted treatment of xylanase and lipase was also investigated. The results are shown in Fig. 7 (b) and (c). At a xylanase dosage of 15 U/g, the addition of PDADMAC increased the filtered water weight from 374 g to 379 g, with little or no improvement to the filtered water effect. The filtered water weight in 30 s was 376 g at 20 U/g of xylanase and 408 g at PDADMAC assisted treatment, an increase of 8.51%. The addition of PDADMAC during the lipase treatment reduced the filtered water weight of the pulp.

The combined process of alkali impregnation and PDADAMAC-assisted cellulase pretreatment was proposed to enhance the efficiency of wheat straw pretreatment. The findings demonstrated that the alkali treatment effectively disrupted the cuticle layer on the surface of wheat straw, thereby exposing the internal fibers. PDADMAC-assisted cellulase treatment can significantly enhance the adsorption of cellulase onto the surface of wheat straw fibers. Specifically, when the amount of PDADMAC was increased to 1.0 × 10^− 3 g/g wheat straw, a remarkable increase in the adsorption rate of cellulase by 42.28% was observed. The addition of PDADMAC to cellulase treatment resulted in improved efficiency, enhanced performance in pulp paper formation, and improved filtration water weight. Furthermore, the filtration capacity of pulp increased by 35.41% and 16.30% at cellulase dosages of 10 U/g and 15 U/g, respectively. The performance of the paper was enhanced when subjected to PDADMAC-assisted xylanase and lipase treatment. This combined treatment effectively improved cellulase efficiency and introduced a novel enzymatic pulping method.

Supplementary Information The online version contains supplementary material available at XXX

Funding

This work was supported by National Key R&D Program of China (No. 2019YFC1905900), the National Natural Science Foundation of China (No. 32230070), Natural Science Foundation of Shandong Province of China (No. ZR2021ZD38), Jinan Innovation Team (No. 2021GXRC023, 202228044), the QUTJBZ Program (No. 2022JBZ01-05), and Taishan Scholars Program.

Conflict of interest The authors declare no competing interests.

Authorship contribution statement

F. H. designed the research. Z. T. discussed the results. H. M. performed the experiments. Z. D. designed the research. X. J., C. S., and D. W. supervised the manuscript. All authors reviewed the manuscript.

Data availability statement

All data generated for this study are included in the main figures. Other data that support the findings of this study are available on request from the corresponding author. Source data are provided with this paper.

Panagiotou G, Olsson L (2007) Effect of compounds released during pretreatment of wheat straw on microbial growth and enzymatic hydrolysis rates. Biotechnol Bioeng 96(2):250-258. https://doi.org/10.1002/bit.21100
Liu H, Xu T, Cai C, Liu K, Liu W, Zhang M, Du H, Si C, Zhang K (2022) Multifunctional Superelastic, Superhydrophilic, and Ultralight Nanocellulose‐Based Composite Carbon Aerogels for Compressive Supercapacitor and Strain Sensor. Adv Funct Mater 32:2113082. https://doi.org/10.1002/adfm.202113082
Liu H, Xu T, Liang Q, Zhao Q, Zhao D, Si C (2022). Compressible cellulose nanofibrils/reduced graphene oxide composite carbon aerogel for solid-state supercapacitor. Adv Compos Hybrid Mater 5:1168-1179. https://doi.org/10.1007/s42114-022-00427-0
Liu K., Liu, W., Li, W. Duan Y, Zhou K, Zhang S, Ni S, Xu T, Du H, Si C (2022) Strong and highly conductive cellulose nanofibril/silver nanowires nanopaper for high performance electromagnetic interference shielding. Adv Compos Hybrid Mater 5:1078-1089. https://doi.org/10.1007/s42114-022-00425-2
Xu T, Du H, Liu H, Liu W, Zhang X, Si C, Liu P, Zhang K (2021) Advanced nanocellulose-based composites for flexible functional energy storage devices. Adv Mater 33:2101368. https://doi.org/10.1002/adma.202101368
Xu T, Liu K, Sheng N, Zhang M, Liu W, Liu H, Dai L, Zhang X, Si C, Du H, Zhang K (2022) Biopolymer-based hydrogel electrolytes for advanced energy storage/conversion devices: Properties, applications, and perspectives. Energy Storage Mater 48:244-262. https://doi.org/10.1016/j.ensm.2022.03.0137.
Liu H, Xu T, Cai C, Liu K, Liu W, Zhang M, Du H, Si C, Zhang K (2022) Multifunctional Superelastic, Superhydrophilic, and Ultralight Nanocellulose‐Based Composite Carbon Aerogels for Compressive Supercapacitor and Strain Sensor. Adv Funct Mater 32:2113082. https://doi.org/10.1002/adfm.202113082
Liu W, Liu K, Du H, Zheng T, Zhang N, Xu T, Pang B, Zhang X, Si C, Zhang K (2022) Cellulose nanopaper: fabrication, functionalization and applications. Nano-Micro Letters 14:104. https://doi.org/10.1007/s40820-022-00849-x
Minaret J, Dutta A (2016) Comparison of liquid and vapor hydrothermal carbonization of corn husk for the use as a solid fuel. Bioresource Technol 200:804-811. https://doi.org/10.1016/j.biortech.2015.11.010.
Varghese LM, Agrawal S, Nagpal R, Mishra OP, Bhardwaj NK, Mahajan R (2020) Eco-friendly pulping of wheat straw using crude xylano-pectinolytic concoction for manufacturing good quality paper. Environ Sci Pollut R 27(27):34574-34582. https://doi.org/10.1007/s11356-020-10119-1
Zhao J, Li X, Qu Y Gao P (2004) Alkaline Peroxide Mechanical Pulping of Wheat Straw With Enzyme Treatment. Appl Biochem Biotech 112(1):13-24. https://doi.org/10.1385/ABAB:112:1:13
Xu H, Chen K, Zhang L, Wu Y (2021) Synchronous silicon removal and viscosity reduction in the soda-oxygen pulping of wheat straw. Cellulose 28(14):9081-9089. https://doi.org/10.1007/s10570-021-04078-0
Xu L, Zhang S, Zhong C, Li B, Yuan Y (2020) Alkali-Based Pretreatment-Facilitated Lignin Valorization: A Review. Ind Eng Chem Res 59(39):16923-16938. https://doi.org/10.1021/acs.iecr.0c01456
Jia Q, Chen J, Yang G, Liu K, Wang Y, Zhang K (2022) Effects of Lipase and Xylanase Pretreatment on the Structure and Pulping Properties of Wheat Straw. Polymers 14(23):5129. https://doi.org/10.3390/polym14235129
An L, Si C, Wang G, Sui W, Tao Z (2019) Enhancing the solubility and antioxidant activity of high-molecular-weight lignin by moderate depolymerization via in situ ethanol/acid catalysis. Ind Crop Prod 128:177-185. https://doi.org/10.1016/j.indcrop.2018.11.009
Kandhola G, Djioleu A, Julie Carrier D, Kim J (2017) Pretreatments for enhanced enzymatic hydrolysis of pinewood: a review. Bioenerg Res 10:1138-1154. https://doi.org/10.1007/s12155-017-9862-3
Xu T, Wang Y, Liu K, Zhao Q, Liang Q, Zhang M, Si C (2023) Ultralight MXene/carbon nanotube composite aerogel for high-performance flexible supercapacitor. Adv Compos Hybrid Mater 6:108. https://doi.org/10.1007/s42114-023-00675-8
Ding Z, Tian Z, Ji X, Dai H, Si C (2022) Bio-inspired catalytic one-step prepared R-siloxane cellulose composite membranes with highly efficient oil separation. Adv Compos Hybrid Mater 5:2138-2153. https://doi.org/10.1007/s42114-022-00517-z
Ye M, Wang S, Ji X, Tian Z, Dai L, Si C (2023) Nanofibrillated cellulose-based superhydrophobic coating with antimicrobial performance. Adv Compos Hybrid Mater 6:30. https://doi.org/10.1007/s42114-022-00602-3
Xu T, Song Q, Liu K, Liu H, Pan J, Liu W, Dai L, Zhang M, Wang Y, Si C, Du H, Zhang K (2023) Nanocellulose‑Assisted Construction of Multifunctional MXene‑Based Aerogels with Engineering Biomimetic Texture for Pressure Sensor and Compressible Electrode. Nano-Micro Lett. 15:98. https://doi.org/10.1007/s40820-023-01073-x
Mai C, Es UK, Militz H (2004) Biotechnology in the wood industry. Appl Microbiol Biot 63(5):477-494. https://doi.org/10.1007/s00253-003-1411-7
Ilić N, Milić M, Beluhan S, Dimitrijević-Branković S (2013) Cellulases: From lignocellulosic biomass to improved production. Energies 16(8):3598. https://doi.org/10.3390/en16083598
Wang Y, Ji X, Liu S, Tian Z, Si C, Wang R, Yang G, Wang D (2022) Effects of two different enzyme treatments on the microstructure of outer surface of wheat straw. Adv Compos Hybrid Ma 5(2):934-947. https://doi.org/10.1007/s42114-021-00395-x
Duan C, Wang X, Zhang Y, Xu Y, Ni Y (2017) Fractionation and cellulase treatment for enhancing the properties of kraft-based dissolving pulp. Bioresource Technol. 224:439-444. https://doi.org/10.1016/j.biortech.2016.10.077
Sun J, Deng Y, Li S, Xu W, Liu G (2022) Enhanced efficiency of enzymatic hydrolysis of wheat straw via freeze–thaw pretreatment. Environ Sci Pollut R 29(37):56696-56704. https://doi.org/10.1007/s11356-022-18893-w
Zhao J, Yao F, Hu C (2022) Enhancing enzymatic hydrolysis efficiency of crop straws via tetrahydrofuran/water co-solvent pretreatment. Bioresource Technol. 358:127428. https://doi.org/10.1016/j.biortech.2022.127428
Han L, Feng J, Zhang S, Ma Z, Wang Y, Zhang X (2012) Alkali pretreated of wheat straw and its enzymatic hydrolysis. Braz J Microbiol 43:53-61. https://doi.org/10.1590/s1517-83822012000100006
Karimi K, Taherzadeh MJ (2016) A critical review of analytical methods in pretreatment of lignocelluloses: Composition, imaging, and crystallinity. Bioresource Technol. 200:1008-1018. https://doi.org/10.1016/j.biortech.2015.11.022
Mansfield SD, Mooney C, Saddler JN (1999) Substrate and enzyme characteristics that limit cellulose hydrolysis. Biotechnol Progr 15(5):804-816. https://doi.org/10.1021/bp9900864
Goshadrou A, Lefsrud M (2017) Synergistic surfactant-assisted [EMIM]OAc pretreatment of lignocellulosic waste for enhanced cellulose accessibility to cellulase. Carbohyd Polym 166:104-113. https://doi.org/10.1016/j.carbpol.2017.02.076
Wang Q, Liu S, Yang G, Chen J, Ni Y (2015) Cationic polyacrylamide enhancing cellulase treatment efficiency of hardwood kraft-based dissolving pulp. Bioresource Technol 183:42-46. https://doi.org/10.1016/j.biortech.2015.02.011
Gejji V, Fernando SD (2018) Harvesting microalgae using ionic polyelectrolytes in an aqueous-organic two-phase system: Screening of separation parameters using model algal particles. Process Biochm 72:188-197. https://doi.org/10.1016/j.procbio.2018.06.010
Saveyn H, Curvers d, Thas o, Van der Meeren p (2008) Optimization of sewage sludge conditioning and pressure dewatering by statistical modelling. Water Res 42(4):1061-1074. https://doi.org/10.1016/j.watres.2007.09.029
Razali MAA, Ahmad Z, Ahmad MSB, Ariffin A (2011) Treatment of pulp and paper mill wastewater with various molecular weight of polyDADMAC induced flocculation. Chem Eng J 166(2):529-535. https://doi.org/10.1016/j.cej.2010.11.011
Yang S, Wen Y, Duan C, Zhang H, Liu X, Ni Y (2019) Poly dimethyl diallyl ammonium chloride assisted cellulase pretreatment for pulp refining efficiency enhancement. Carbohyd Polym 203:342-348. https://doi.org/10.1016/j.carbpol.2018.09.079
Jervis EJ, Haynes CA, Kilburn DG (1997) Surface Diffusion of Cellulases and Their Isolated Binding Domains on Cellulose. J Biol Chem 272(38):24016-24023. https://doi.org/10.1074/jbc.272.38.24016
Pierre G, Maache-Rezzoug Z, Sannier F, Rezzoug S, Maugard T (2011) High-performance hydrolysis of wheat straw using cellulase and thermomechanical pretreatment. Process Biochem 46(11):2194-2200. https://doi.org/10.1016/j.procbio.2011.09.002
Zheng Q, Zhou T, Wang Y, Cao X, Wu S, Zhao M, Wang H, Xu M, Zheng B, Zheng J, Guan X (2018) Pretreatment of wheat straw leads to structural changes and improved enzymatic hydrolysis. Sci Rep-Uk 8(1):1321. https://doi.org/10.1038/s41598-018-19517-5
Zhu P, Moran-Mirabal JM, Luterbacher JS, Walker LP, Craighead HG (2011) Observing Thermobifida fusca cellulase binding to pretreated wood particles using time-lapse confocal laser scanning microscopy. Cellulose 18(3):749-758. https://doi.org/10.1007/s10570-011-9506-2
Ding S, Liu Y, Zeng Y, Himmel ME, Baker JO, Bayer EA (2012) How does plant cell wall nanoscale architecture correlate with enzymatic digestibility? Science 338(6110):1055-1060. https://doi.org/10.1007/s12155-015-9703-1
Moreno-Atanasio R, Williams RA, Jia X (2010) Combining X-ray microtomography with computer simulation for analysis of granular and porous materials. Particuology 8(2):81-99. https://doi.org/10.1016/j.partic.2010.01.001
Zhang L, Larsson A, Moldin A, Edlund U (2022) Comparison of lignin distribution, structure, and morphology in wheat straw and wood. Ind Crop Prod 187:115432. https://doi.org/10.1016/j.indcrop.2022.115432
Yu H, Liu R, Shen D, Wu Z, Huang Y (2008) Arrangement of cellulose microfibrils in the wheat straw cell wall. Carbohyd Polym 72(1):122-127. https://doi.org/10.1016/j.carbpol.2007.07.035
Lecourt M, Sigoillot J, Petit-Conil M (2010) Cellulase-assisted refining of chemical pulps: Impact of enzymatic charge and refining intensity on energy consumption and pulp quality. Process Biochem. 45(8):1274-1278. https://doi.org/10.1016/j.procbio.2010.04.019

No competing interests reported.

Download PDF

Journal Publication

published 14 Dec, 2023

Read the published version in Advanced Composites and Hybrid Materials →

Editorial decision: Major revision
27 Sep, 2023
Reviews received at journal
21 Sep, 2023
Reviewers agreed at journal
17 Sep, 2023
Reviewers invited by journal
17 Sep, 2023
Editor assigned by journal
17 Sep, 2023
Submission checks completed at journal
11 Sep, 2023
First submitted to journal
07 Sep, 2023

You are reading this latest preprint version

Combined alkali impregnation and poly dimethyl diallyl ammonium chloride-assisted cellulase absorption for high-efficiency pretreatment of wheat straw

Status:

Journal Publication

Version 1

Abstract

Figures

1. Introduction

2. Experimental

2.1. Materials and chemicals

2.2. Raw materials pretreatment

2.3. Alkali impregnation

2.4. Cellulase treatment

2.5. Determination of Cellulase adsorption

2.6. Laser confocal scanning microscope (CLSM) analysis

2.7. Wheat straw three-dimensional structure

2.8. Pulp performance analysis

3. Result and discussion

3.2. Alkali impregnation

3.3. Adsorption of cellulase on wheat straw

3.4. Cellulase distribution

3.5. Three-dimensional structure analysis of wheat straw

3.6. Pulp characteristics analysis

4. Conclusions

Declarations

References

Additional Declarations

Status:

Journal Publication

Version 1