Search

BackgroundTrichoderma reesei is an organism extensively used in the bioethanol industry, owing to its capability to produce enzymes capable of breaking down holocellulose into simple sugars. The uptake of carbohydrates generated from cellulose breakdown is crucial to induce the signaling cascade that triggers cellulase production. However, the sugar transporters involved in this process in T. reesei remain poorly identified and characterized.ResultsTo address this gap, this study used temporal membrane proteomics analysis to identify five known and nine putative sugar transporters that may be involved in cellulose degradation by T. reesei. Docking analysis pointed out potential ligands for the putative sugar transporter Tr44175. Further functional validation of this transporter was carried out in Saccharomyces cerevisiae. The results showed that Tr44175 transports a variety of sugar molecules, including cellobiose, cellotriose, cellotetraose, and sophorose.ConclusionThis study has unveiled a transporter Tr44175 capable of transporting cellobiose, cellotriose, cellotetraose, and sophorose. Our study represents the first inventory of T. reesei sugar transportome once exposed to cellulose, offering promising potential targets for strain engineering in the context of bioethanol production.

Lignin can affect the enzymatic hydrolysis efficiency of lignocellulose. In this study, the lignin isolated from sugarcane bagasse (SCB) pretreated with p-toluenesulfonic acid (PL) was firstly aminated, and then the effects of PL and aminated PL (APL) on the bagasse enzymatic hydrolysis efficiency (EHE) were investigated. The results showed that the addition of PL and APL promoted the EHE, and EHE with APL (73.82 %) was higher than PL (51.39 %). To explore the reason, the data were further analyzed including cellulase adsorption capacity, enzyme activity, cellulase-lignin interaction, and molecular docking. It was found that APL adsorbed more cellulase (27.83 mg protein/g lignin) than PL (4.96 mg protein/g lignin), resulting from the greater interaction force and lower binding free energy between APL and cellulase. The addition of APL more remarkably enhanced the cellobiohydrolase and endoglucanase activities than PL due to more effectively inducing cellulase conformation optimization. [Display omitted] • Enzymatic hydrolysis of cellulosic substrate was enhanced from 45.83 % to 73.82 % by aminated lignin. • Aminated lignin adsorbed more cellulase molecules. • Activities of cellobiohydrolase (CBH) and endoglucosidase (EG) were promoted by aminated lignin. • Aminated lignin owned lower binding energy with cellulase. [ABSTRACT FROM AUTHOR]

The process of bioethanol production has several economic drawbacks such as the cost of enzymes, i.e., cellulase, which hydrolyze cellulose to produce fermentable sugars. In this study, to reduce the production cost of cellulase, agricultural wastes such as wheat straw (WS) and rice straw (RS) were used as carbon sources for cellulase production through solid-state fermentation. First, the standard cellulase production conditions were optimized, the initial moisture content of the solid medium was 60%, the biomass particle size was 100 µm to 4 mm size mixed, and the optimal carbon/nitrogen (C/N) ratio in the medium of WS and RS was 59.0 and 41.2, respectively. Subsequently, to simplify process handling, eliminating trace elements such as MgSO4, CaCl2, FeSO4, MnSO4, ZnSO4, CoCl2, and phosphorous compounds such as KH2PO4 in the general Mandel's medium was used for cellulase production medium and compared with the standard medium. Maximum 5.4 filter paper unit (FPU)/g-substrate (WS) and 5.3 FPU/g-substrate (RS) were attained under trace element eliminating medium; these were similar to that from the standard medium of WS (4.8 FPU/g-substrate) and RS (5.7 FPU/g-substrate). Moreover, the produced crude cellulases from RS were evaluated for their potential in hydrolysis of alkaline-treated RS. The performances of the crude cellulases were similar to those of commercial cellulases. [ABSTRACT FROM AUTHOR]

Introduction: Several species of cellulolytic bacteria display cellulosomes, massive multi-cellulase containing complexes that degrade lignocellulosic plant biomass (LCB). A greater understanding of cellulosome structure and enzyme content could facilitate the development of new microbial-based methods to produce renewable chemicals and materials. Methods: To identify novel cellulosome-displaying microbes we searched 305,693 sequenced bacterial genomes for genes encoding cellulosome proteins; dockerin-fused glycohydrolases (DocGHs) and cohesin domain containing scaffoldins. Results and discussion: This analysis identified 33 bacterial species with the genomic capacity to produce cellulosomes, including 10 species not previously reported to produce these complexes, such as Acetivibrio mesophilus. Cellulosome-producing bacteria primarily originate from the Acetivibrio, Ruminococcus, Ruminiclostridium , and Clostridium genera. A rigorous analysis of their enzyme, scaffoldin, dockerin, and cohesin content reveals phylogenetically conserved features. Based on the presence of a high number of genes encoding both scaffoldins and dockerin-fused GHs, the cellulosomes in Acetivibrio and Ruminococcus bacteria possess complex architectures that are populated with a large number of distinct LCB degrading GH enzymes. Their complex cellulosomes are distinguishable by their mechanism of attachment to the cell wall, the structures of their primary scaffoldins, and by how they are transcriptionally regulated. In contrast, bacteria in the Ruminiclostridium and Clostridium genera produce 'simple' cellulosomes that are constructed from only a few types of scaffoldins that based on their distinct complement of GH enzymes are predicted to exhibit high and low cellulolytic activity, respectively. Collectively, the results of this study reveal conserved and divergent architectural features in bacterial cellulosomes that could be useful in guiding ongoing efforts to harness their cellulolytic activities for bio-based chemical and materials production. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this experiment was to explore the effect of adding cellulase and laccase on fermentation quality and microbial community in mixed silage of corn stover and wet brewer's grains. Try to a new approach for the proper preservation and utilization of the agro-industrial by-products (corn stover and wet brewer's grains). Methods: The experiment was divided into four groups: CK (control), C (cellulase, 120 U/g fresh matter [FM]), L (laccase, 50 U/g FM), CL (cellulase 120 U/g FW and laccase 50 U/g FM), and the chemical composition, fermentation quality, microbial population and microbial community in mixed silage of corn stover and wet brewer's grains after 30 day's fermentation were determined. Results: Compared to control, the addition of cellulase significantly increased crude protein (CP), water-soluble carbohydrate (WSC), lactic acid bacteria (LAB) counts, while significantly decreased the neutral detergent fiber (NDF), acid detergent fiber (ADF) content (P < 0.05). Adding laccase significantly decreased the acid detergent lignin (ADL) content (P < 0.05). Combined application of cellulase and laccase significantly increased the CP, WSC content and LAB counts, while significantly decreased pH value, NDF, ADF and ADL content (P < 0.05), thereby improving fermentation quality. In addition, the application of cellulase and laccase increased the abundance of Firmicutes and LAB genera, and decreased microbial diversity level of the sample. Conclusion: The combined application of cellulase and laccase further improved fermentation quality and microbial community in mixed silage of corn stover and wet brewer's grains. [ABSTRACT FROM AUTHOR]

The fate of biobased and biodegradable cellulose-derived plastics in landfills represents an important topic from economic and environmental points of view. Anaerobic digestion is a cost-effective waste-to-energy technology. The behaviour of six polymer types—that is, cellulose (C), cellulose acetate (CA), viscose (V), nanocellulose (NC), acetate textile (AT), and heteropolysaccharide pectin (P)—was studied under anaerobic batch mesophilic conditions in a landfill leachate for 147 days. The cumulative biogas production was as follows: C>V=CA>>AT>>NC=P. Metagenomic analysis revealed notable variations in the proportion of bacterial and archaeal domains with the highest archaeal abundance in the presence of CA (80.2%) and C (78.5%). At the end of digestion, cellulolytic, hydrolytic, and dehydrogenase activities were measured in the intact samples, as well as the liquid and solid fractions, under aerobic and anaerobic conditions. Cellulolytic activity in P was detected only in the pellet, while in NC, activity was mostly in the supernatant under both aerobic and anaerobic conditions. Scanning electron microscopy and confocal scanning laser microscopy showed a defragmentation and degradation of polymeric substrates as well as microbial colonisation. Based on the results, landfill leachate is appropriate for the anaerobic biodegradation of cellulose-derived polymers; however, the process is polymer specific. [ABSTRACT FROM AUTHOR]

Cellulases and xylanases are plant cell wall-degrading enzymes (CWDEs) that are critical to sustainable bioproduction based on renewable lignocellulosic biomass to reduce carbon dioxide emission. Currently, these enzymes are mainly produced from filamentous fungi, especially Trichoderma reesei and Penicillium oxalicum. However, an in-depth comparison of these two producers has not been performed. Although both P. oxalicum and T. reesei harbor CWDE systems, they exhibit distinct features regulating the production of these enzymes, mainly through different transcriptional regulatory networks. This review presents the strikingly different modes of genome-wide regulation of cellulase and xylanase biosynthesis in P. oxalicum and T. reesei, including sugar transporters, signal transduction cascades, transcription factors, chromatin remodeling, and three-dimensional organization of chromosomes. In addition, different molecular breeding approaches employed, based on the understanding of the regulatory networks, are summarized. This review highlights the existence of very different regulatory modes leading to the efficient regulation of CWDE production in filamentous fungi, akin to the adage that "every road leads to Rome." An understanding of this divergence may help further improvements in fungal enzyme production through the metabolic engineering and synthetic biology of certain fungal species. [ABSTRACT FROM AUTHOR]

The present work explored the coupled hydrothermal pretreatment and cellulase hydrolysis (HPCH) for production of bacillomycin D from sorghum straws by Bacillus subtilis NS-174. The results indicated that HPCH treated sorghum straws had weaker absorption, heavier mass loss and higher crystallinity, and displayed loose and destructive fiber structures. Degradation of hemicellulose and lignin contributhed to yielding glucose and 68.94 g/L of glucose was obtained in HPCH treated hydrolysate. High level of glucose in pretreated sorghum straw hydrolysate was helpful for improving bacillomycin D production. When performed by 3rd round (feeding at 144 h) fed-batch fermentation, bacillomycin D production and production rate were obtained to be 2351.07 mg/L and 113.36 mg/L.h in B. subtilis NS-174, respectively. [Display omitted] • Green sorghum staw utilization process was explored for bacillomycin D production. • Degradation of hemicellulose and lignin contributed to yielding glucose. • Feeding HPCH treated hydrolysate boosted bacillomycin D production. • 68.94 g/L of glucose and 2351.07 mg/L of bacillomycin D were obtained. [ABSTRACT FROM AUTHOR]

Saccharification of cellulosic material is crucial before utilizing it as the feedstock of fermentation processes. This study focuses on developing of robust catalysts for enzymatic hydrolysis of paper waste. Cellulase enzyme was immobilized on Fe3O4 magnetic nanoparticles (MNPs) via multi-covalent bonds. Therefore, the attachments of MNPs were performed by three approaches (3-aminopropyl)triethoxysilane (APTES) (Method I), polyethyleneimine (PEI) (Method II), and both monolayer molybdenum disulfide and PEI (MoS2-PEI) (Method III). The biocatalysts were characterized using Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA). The immobilization yield and loading efficiency of cellulase were determined at 38.65% and 162 mg g−1 in Method I, 13.33% and 31 mg g−1 in Method II, and 14.38% and 33 mg g−1 in Method III. The specification of the biocatalysts was determined for the hydrolysis of filter paper, carboxymethylcellulose (CMC), microcrystalline cellulose, and cellobiose. The total cellulase activity was 2.77, 0.943, 1.38, and 2.02 µmolGlucose mgEnzyme−1 h−1for free-cellulase and the immobilized biocatalysts prepared by Method I, II, and III, respectively. The prepared biocatalyst in Method I maintained 54.54% of its original activity after five cycles, which was more robust than Method II (20.25%) and Method III (12.33%). Further studies were performed on the saccharification of paper waste. The results showed the biocatalyst obtained by Method II resulted in 5.8 folds of higher glucose than the free-cellulase. The highest glucose recovery of about 72.47% was achieved after 48 h using the immobilized biocatalyst prepared by Method II. [ABSTRACT FROM AUTHOR]

Baicalein and wogonin, two health-promoting flavonoid aglycones in Scutellaria baicalensis Georgi roots, have better bioactivity and bioavailability than their glycoside precursors (baicalin and wogonoside). The search for novel microorganisms for the fermentation of S. baicalensis roots to improve the yields of baicalein and wogonin is of great interest in the food and nutraceutical industries. In this study, a novel endophytic fungus (Penicillium rubens) capable of producing cellulase (0.82 ± 0.12 U/mL) and β-glucosidase (4.55 ± 0.97 U/mL) was used to ferment S. baicalensis roots to obtain high yields of baicalein and wogonin. Semi-solid-state fermentation with homogeneous fungal cultures was found to be the appropriate strategy. Under the optimal fermentation parameters (temperature 30 °C, inoculation dose of fungal cultures 4 mL/g, and time 60 h), the yields of baicalein and wogonin (46.95 ± 4.98 mg/g DW and 31.41 ± 9.36 mg/g DW) from S. baicalensis roots were tremendously increased by 16.13-fold and 15.47-fold over control, respectively. Results of industrial enzyme bioprocessing and scanning electron microscope indicated that the remarkable increase in aglycone product yields could be due to the synergistic effects of cellulase and β-glucosidase produced by P. rubens on cell wall hydrolysis and glycoside deglycosylation. In addition, extracts of S. baicalensis roots fermented by P. rubens showed a significant increase in antioxidant and antimicrobial activities. Overall, the semi-solid-state fermentation of S. baicalensis roots using the novel P. rubens was an effective strategy that could yield high quantities of baicalein and wogonin, which had promising potential in the food and nutraceutical industries. [ABSTRACT FROM AUTHOR]

The production of cellulolytic enzymes in response to inducible carbon sources is mainly regulated at the transcriptional level in filamentous fungi. We have identified a cellobiose-response regulator (ClbR) controlling the expression of cellulolytic enzyme-encoding genes in Aspergillus aculeatus. However, the engineering potential of combining the deletion of transcriptional repressors with the overexpression of transcriptional activators to enhance enzyme production has not been analyzed. Here, we investigated the effect of the deletion of the transcriptional repressor creA and the overexpression of the transcriptional activator clbR in enzyme production in A. aculeatus. Here, we verified that a combination of creA deletion and clbR overexpression (Δc&OE) improved cellulase, β-1,4-xylanase, and β-glucosidase production. Cellulase and β-1,4-xylanase production increased 3.4- and 8.0-fold in Δc&OE compared with the host strain (MR12) at 96-h incubation, respectively. β-Glucosidase production in Δ creA and Δc&OE increased approximately 5.0-fold compared with that in MR12 at 240-h incubation. Transcriptional analysis revealed that the increase in enzyme production was due to increased expression of cellobiohydrolase, endo-β-1,4-glucanase, β-1,4-xylanase, and β-glucosidase 1 (bgl1). Interestingly, bgl1 expression in Δ creA increased in a dose-dependent manner in response to glucose. Thus, combinational manipulation of transcription factors improved cellulase, xylanase, and β-glucosidase production in A. aculeatus. [ABSTRACT FROM AUTHOR]

The enzyme-assisted approaches for plant phenolics extraction are more eco-friendly methods compared to acid or alkaline hydrolysis. Carbohydrase enzymes can release free phenolics from plant materials by cleaving the glycosidic bonds between phenolic compounds and cell wall polymers. In this study, the efficiency of carbohydrase-assisted treatment approaches was evaluated to extract bioactive phenolics from hawthorn (Crataegus orientalis) fruit residues. Enzymatic treatment of the fruits was operated by using a crude cellulolytic enzyme cocktail from Rhizomucor miehei NRRL 5282 and a pectinase preparate from Aspergillus niger. Both cellulase and combined cellulase–pectinase treatments improved the total phenolic content (TPC) and antioxidant activity of extracts. The TPC increased to 1899 ± 27 mg gallic acid equivalents/100 g dry matter during the combined enzyme treatment, showing a strong correlation with the average antioxidant capacity determined by ferric-reducing antioxidant power (1.7-fold increment) and 2,2-diphenyl-1-picrylhydrazyl (1.15-fold increment) reagents. The major phenolics in enzyme-treated extracts were vanillic and ferulic acids, the concentrations of which increased 115.6-fold and 93.9-fold, respectively, during carbohydrase treatment. The planktonic growth of Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Chromobacterium violaceum was slightly inhibited by the extracts with minimum inhibitory concentration values between 15.0 and 77.9 mg/mL, while the yeasts tested were quite resistant to the samples. B. subtilis and yeast biofilms were sensitive to the enzyme-treated extracts, which also showed quorum-sensing inhibitory effects against C. violaceum. The obtained bioactive hawthorn extracts hold potential as a natural source of antioxidants and antimicrobials. [ABSTRACT FROM AUTHOR]

Licorice roots can release low-molecular-weight oxalic acid (OA). However, the allelopathic effects of OA on licorice are unknown. This study presents an investigation of the effects of exogenous OA treatment on licorice roots through transcriptomic and physiological analyses. Transcriptomic analysis demonstrated that following OA treatment, differentially expressed genes (DEGs) were primarily involved in the phenylpropanoid metabolism pathway. At 6 h, the expression levels of genes associated with this pathway, such as PAL, CHS, POD, cellulase, CPY, MYB, and bHLH, were upregulated. The metabolism of related metabolites, such as flavonoids and lignin, also increased. These findings suggest that the phenylpropanoid metabolism pathway may play a significant role in the response to OA treatment. In addition, the activities of GST, CAT, and POD markedly increased, whereas the content of H2O2 gradually decreased, indicating that OA can activate the antioxidant protective capabilities of licorice roots. These findings suggest that OA may enhance the antioxidant defense of licorice root, as well as the effectiveness of its flavonoid constituents (to a certain degree). Our findings provide valuable theoretical insight into the allelopathic effects of licorice roots. [ABSTRACT FROM AUTHOR]

High-value metabolites, such as enzymes and biofuels, can be produced from various agro-industrial waste containing high percentages of cellulose and hemicellulose. Aspergillus niger ITV02 demonstrates high potential in cellulases production, the key enzyme for converting lignocellulosic materials into fermentable sugars to produce second-generation bioethanol (bioethanol 2G). This study evaluated five lignocellulosic residues of agricultural importance: sugarcane bagasse (SCB), sorghum bagasse (SB), corn stubble (CS), barley straw (BS) and rice husk (RH) as substrates for cellulase production. The temperature, pH and stirring conditions were optimized using a Box–Behnken design to identify the most suitable conditions for cellulase production while minimizing nitrogen concentrations. The results indicate that the best way of propagation A. niger ITV02 is through the use of spores as an inoculant, in conjunction with the use of materials with a high cellulose/lignin ratio, such as CS and SB for the generation of cellulases. These conditions promote the expression of cellulases towards β-glucosidase production, unlike materials with lower cellulose/lignin ratios like BS and RH, which exhibited lower cellulase activity. The optimal conditions for cellulase production by A. niger ITV02 were determined to be 33 °C, pH 5.3, and 200 rpm, resulting in a 1.7-fold increase in Exoglucanase (FPase activity) (from 0.127 to 0.215 U/mL). These findings demonstrate the potential to enhance FPase activity by utilizing substrates with high cellulose/lignin content and implementing optimal operational conditions without the need to raise the nitrogen content of the basal medium, thus mitigating the economic impact of cellulase production. [ABSTRACT FROM AUTHOR]

We examine feedstock cost and minimum selling price for ethanol production from corn stover as a function of scale, stover yield, participation rate, and price incentives for two conversion technologies: a conventional base case featuring thermochemical pretreatment with added cellulase, and an advanced case featuring consolidated bioprocessing with cotreatment (C‐CBP). Delivered feedstock cost ranged from $85 Mg−1 at small (10 million gallons year−1 or ~38 million L year−1) scale with high yield and participation rates to $124 Mg−1 at large scale (60 million gallons year−1 or 227 million L year−1) and low yield and participation rates. The minimum ethanol selling price (MESP) was approximately twofold lower for the advanced case compared with the base case. The payback period was several times lower for the advanced case compared with the base case, with increasing disparity at smaller scales, and was highly sensitive to ethanol price supports. For both C‐CBP and the conventional processing paradigm, MESP decreased with increasing scale, indicating that the cost penalty due to higher feedstock transport distances was more than outweighed by lower capital costs. However, the cost penalty for operation at small scale, expressed in $ gallon−1 ethanol, is lower for C‐CBP than for the conventional paradigm by roughly twofold. Particularly for initial applications of C‐CBP, we speculate that this cost penalty will likely be modest compared with the anticipated benefits of small‐scale operation such as increased opportunity to use existing infrastructure, easier plant siting and supply chain establishment, and lower total investment required. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The microbial landscape within termite guts varies across termite families. The gut microbiota of lower termites (LT) is dominated by cellulolytic flagellates that sequester wood particles in their digestive vacuoles, whereas in the flagellate-free higher termites (HT), cellulolytic activity has been attributed to fiber-associated bacteria. However, little is known about the role of individual lineages in fiber digestion, particularly in LT. Results: We investigated the lignocellulolytic potential of 2223 metagenome-assembled genomes (MAGs) recovered from the gut metagenomes of 51 termite species. In the flagellate-dependent LT, cellulolytic enzymes are restricted to MAGs of Bacteroidota (Dysgonomonadaceae, Tannerellaceae, Bacteroidaceae, Azobacteroidaceae) and Spirochaetota (Breznakiellaceae) and reflect a specialization on cellodextrins, whereas their hemicellulolytic arsenal features activities on xylans and diverse heteropolymers. By contrast, the MAGs derived from flagellate-free HT possess a comprehensive arsenal of exo- and endoglucanases that resembles that of termite gut flagellates, underlining that Fibrobacterota and Spirochaetota occupy the cellulolytic niche that became vacant after the loss of the flagellates. Furthermore, we detected directly or indirectly oxygen-dependent enzymes that oxidize cellulose or modify lignin in MAGs of Pseudomonadota (Burkholderiales, Pseudomonadales) and Actinomycetota (Actinomycetales, Mycobacteriales), representing lineages located at the hindgut wall. Conclusions: The results of this study refine our concept of symbiotic digestion of lignocellulose in termite guts, emphasizing the differential roles of specific bacterial lineages in both flagellate-dependent and flagellate-independent breakdown of cellulose and hemicelluloses, as well as a so far unappreciated role of oxygen in the depolymerization of plant fiber and lignin in the microoxic periphery during gut passage in HT. Ak1UNwnHwhcNN-Fj12kHob Video Abstract [ABSTRACT FROM AUTHOR]

The production of lignocellulytic enzymes by microwave-radiated Pleurotus sajor-caju was assayed. Wheat straw was employed as substrate to P. sajor-caju for production of laccase, manganese peroxidase (MnPase), filter-paperase (FPase), carboxmethyl cellulase (CMCase), and cellulase (as evaluated using microcrystalline cellulose). P. sajor-caju exposed to 10 s of microwave radiation (MR) showed maximum growth with colony radius of 7.17 ± 0.45 cm, while with increasing the exposure time up to 50 s the growth decreased up to 2.67 ± 0.22 cm. Moreover, it failed to grow at 80 s of exposure time. Cellulase, MnPase, FPase, CMCase, and laccase activities were induced to 37 ± .0.54, 49 ± 2.36, 189 ± 2.12, 0.37 ± 0.06, and 1.58 ± 0.03 U/mL compared to that at control 31 ± 0.25, 46 ± 1.25, 177 ± 1.65, 0.28 ± 0.03, and 1.37 ± 0.12 U/mL, respectively as a result of P. sajor-caju exposure to 10 s of MR. As the exposure time increased, these enzymes activity decreased. Different levels of moisture with surfactant (polysorbate 80) were applied to optimize the enzymes activities at 10 s of exposure time. The optimum activities 3.15 ± 0.23, 0.62 ± 0.06, 269 ± 5.36, 65 ± 1.63, and 48 ± 0.98 U/mL were recorded for cellulase, MnPase, FPase, CMCase, and laccase, respectively at 70% of moisture and 0.15 mL/L of polysorbate 80. [ABSTRACT FROM AUTHOR]

The effects of laboratory beating on unbleached regular grade pine kraft pulp (UPKP), pre-treated with commercial cellulase/hemicellulase enzymatic preparation (C/HEP) were assessed using degrees of Schopper-Riegler (°SR) and fibre-quality numbers (FQN). The tests showed a significant increase in the °SR (used in papermaking laboratories and industry to assess the degree of beating) of the UPKP after its enzymatic pre-treatment in the amount of 0.25 to 5.0 mL/kg of pulp and beating. However, only a several percent reduction of beating time was observed when the effect of this pretreatment of pulp on the speed of its beating was determined using another method. The treatment of the pulp selected for research with C/HEP before beating negatively influenced its strength properties after this process. The results correlated well with the most important basic fiber properties from the standpoint of papermaking. [ABSTRACT FROM AUTHOR]

In order to alleviate environmental pollution and the waste of resources caused by improper disposal of fungal residue, this study used fungal residue waste, which was treated with NaClO alkaline solution and nitric acid ethanol method for rough fiber preparation. The enzymatic hydrolysis of cellulase conditions were optimized using response surface optimization method, and the optimal preparation parameters were: enzyme addition of 5000 U/g, enzymatic hydrolysis temperature of 52 °C, enzymatic hydrolysis time of 2.65 h, and solid-liquid ratio of 1:20. The Fr-MCC purity reached over 97%. The Fr-MCC obtained had an irregular granular or lamellar aggregation morphology, typical I-type cellulose crystal structure and molecular features, good thermal stability, and was similar in properties to commercial MCC. It was judged to be suitable for further processing and manufacturing of biological base materials. This approach was shown to improve the utilization efficiency of cultivation residues, reducing environmental pollution caused by the accumulation of cultivation residues, and providing new methods and ideas for the preparation of MCC and other bio-based materials. [ABSTRACT FROM AUTHOR]

In the last few decades, the increasing levels of environmental pollution have prompted a shift towards alternative energy sources and biobased solutions, such as lignocellulosic biomass. Lignocellulosic biomass (LB) is primarily derived from plants and is composed mainly of polysaccharides, namely cellulose, hemicellulose, and the aromatic polymer lignin. Hazelnut shells (HS), with a high lignin content of 43%, hemicellulose of 30%, and cellulose of 26%, hold promise as a valuable source of LB. In order to process those LB, lignin and hemicellulose are separated using various treatment methods. However, instead of being used solely for combustion, lignin-containing materials can be valorized for a range of purposes, from biomedical applications to the energy sector. In this study, the enzymatic hydrolysis of HS was conducted over different time periods (24, 48, 72, and 96 hours), at different temperature values with varying enzyme concentrations (0.05, 0.1, and 0.25 mL of cellulase/xylanase enzyme cocktail). To enhance the enzymatic hydrolysis, an alkaline pretreatment method using sodium hydroxide (NaOH) was employed. The results demonstrate that the maximum sugar concentration was achieved at 50°C, after 72 hours, and with a cellulase/xylanase cocktail concentration of 0.1 mL. [ABSTRACT FROM AUTHOR]

Trichoderma species have been reported as masters in producing cellulolytic enzymes for the biodegradation of lignocellulolytic biomass and biocontrol agents against plant pathogens and pests. In our previous study, a novel Trichoderma strain LZ117, which shows potent capability in cellulase production, was isolated. Herein, we conducted multilocus phylogenetic analyses based on DNA barcodes and performed time-scaled phylogenomic analyses using the whole genome sequences of the strain, annotated by integrating transcriptome data. Our results suggest that this strain represents a new species closely related to T. atrobrunneum (Harzianum clade). Genes encoding carbohydrate-active enzymes (CAZymes), transporters, and secondary metabolites were annotated and predicted secretome in Trichoderma sp. LZ117 was also presented. Furthermore, genetic manipulation of this strain was successfully achieved using PEG-mediated protoplast transformation. A putative transporter gene encoding maltose permease (Mal1) was overexpressed, which proved that this transporter does not affect cellulase production. Moreover, overexpressing the native Cre1 homolog in LZ117 demonstrated a more pronounced impact of glucose-caused carbon catabolite repression (CCR), suggesting the importance of Cre1-mediated CCR in cellulase production of Trichoderma sp. LZ117. The results of this study will benefit further exploration of the strain LZ117 and related species for their applications in bioproduction. [ABSTRACT FROM AUTHOR]

Simple Summary: The black soldier fly (Hermetia illucens L.) is a saprophagous insect belonging to the Stratiomyidae family that can degrade organic waste and convert it into high-quality insect protein and lipid. Corn straw is a kind of prevalent agricultural waste. In this study, black soldier fly larvae were reared with corn straw to obtain larval biomass and consume corn straw. The results showed that most of the black soldier fly larvae could survive and gain weight when fed with corn straw. Gut microorganisms could respond to the substrates, and four cellulase-producing strains isolated from the gut were beneficial to digesting corn straw. Corn straw is considered a renewable biomass energy source, and its unreasonable disposal leads to resource waste and environmental pollution. Black soldier fly (Hermetia illucens L.) larvae (BSFL) facilitate the bioconversion of various types of organic wastes. In this study, we found that 88% of BSFL survived, and 37.4% of corn straw was digested after 14 days of feeding with corn straw. Contrary to expectations, the pretreatment of corn straw with alkaline hydrogen peroxide did not promote its digestion but rather reduced the growth and survival rates of BSFL. Acinetobacter, Dysgonomonas, and unclassified Enterobacteriaceae were the abundant genera in the BSFL gut fed with corn straw. Compared with the standard diet, the relative abundances of carbohydrate metabolism genes, such as the gene abundances of β-glucosidase and α-glucosidase, were higher with corn straw as the substrate. These results suggested that the gut microbial community could regulate suitable and functional microorganisms in response to the substrates. Furthermore, four cellulase-producing strains, namely Klebsiella pneumoniae, Proteus mirabilis, Klebsiella oxytoca, and Providencia rettgeri, were isolated from the guts of corn straw BSFL. These four strains helped increase the conversion rates of corn straw, the weights of BSFL, and survival rates. In summary, we reared BSFL with corn straw and discovered the functions of gut microorganisms in adapting to the substrates. We also isolated four cellulase-producing strains from the BSFL guts and declared the benefits of BSFL digesting corn straw. [ABSTRACT FROM AUTHOR]

The experiment was aimed to optimize enzyme production process of Aspergillus oryzae, improve the complex enzyme activity and dry matter digestibility. The enzyme production performance of As‐ pergillus oryzae strains was verified. After production of Aspergillus oryzae strains, viable bacterial enumeration, toxin detection, and in vitro digestion were performed. The activities of three hydrolases, cellulase, xylanase, and protease were utilized to optimize the inorganic salt, nitrogen source, water content, and carbon source in the fermentation matrix. The cultured Aspergillus oryzae was then subjected to in vi‐ tro digestion, and the total sugar content of the remaining residue was measured. Our results showed that Aspergillus oryzae strains could produce seven different types of enzymes: protease, cellulase, xylanase, lipase, amylase, phytase and pectinase. During the fermentation process, the contents of aflatoxins and corn gibberellic ketene aflatoxin were all lower than the limit values. The fermentation matrix with bran as substrate was cultured at 30 ℃ for 5 days with the addition of 4% seed kojae, 0.5% ammonium sulfate, 2% yeast extract, 2% bran and 55% water content. There were different enzyme activities measured: the cellulase activity was 15.30 U/g, the xylanase activity was 17.91 U/g, and the acid protease activity was 622.56 U/g. The activity of neutral protease was 1 822.56 U/g, and that of alkaline protease was 6 024.79 U/g. The addition of Aspergillus oryzae culture significantly increased the digestibility of corn straw (P<0.05), the digestibility increased by 59.46%, and the total sugar content in the residue of rice straw after digestion in vitro decreased by 9.12%. The findings demonstrated that the Aspergillus oryzae culture could lower production costs, increase feed utilization, and improve the digestibility of dry matter. [ABSTRACT FROM AUTHOR]

A dual-enzyme cascade catalytic system (Cu-rGO-Fe3O4-GA-CEL-PEI-GOD) was prepared by co-immobilizing cellulase (CEL) and glucose oxidase (GOD) on a nanocomposite (Cu-rGO-Fe3O4) to efficiently catalyze the conversion of carboxymethyl cellulose (CMC) to gluconic acid. A layer-by-layer strategy was used by adding polyethyleneimine (PEI) to allow the upper enzyme layer to attach to the lower neighboring layer, increasing the loading capacity of the support. The loading capability of CEL and GOD on Cu-rGO-Fe3O4-GA-CEL-PEI-GOD were 55.034 mg g−1 and 12.4 mg g−1, respectively. The specific activity of CEL on Cu-rGO-Fe3O4-GA-CEL was 74.3 U·g−1, and that of immobilized CEL after cross-linking PEI was 25.45 U·g−1, which could retain 34.253% of the enzyme activity. The specific activity of GOD on Cu-rGO-Fe3O4-GA-CEL-PEI-GOD was 30.9 U·g−1. The carrier Cu-rGO-Fe3O4 has peroxidase-like activity, which can timely remove harmful H2O2 to the enzyme, thereby improving the yield of gluconic acid and the stability of biocatalysts. The yield of gluconic acid with Cu-rGO-Fe3O4-GA-CEL-PEI-GOD reached 96.04% within 2 h, higher than the control systems for comparison. In addition, the Cu-rGO-Fe3O4-GA-CEL-PEI-GOD maintained 82.61% of catalytic activity even after undergoing seven cycles of reaction. The dual-enzyme catalytic systems had shallow temperature and pH optima of 40 °C and 4.5. Such a chemoenzymatic cascade system provides a new strategy for the conversion from CMC to gluconic acid in one-step. Enzymatic conversion of sodium carboxymethyl cellulose (CMC-Na) to gluconic acid. [ABSTRACT FROM AUTHOR]

This review explores the research work on diverse cellulase purification approaches. Cellulase is an industrial biocatalyst applied to cellulosic breakdown. This biocatalyst has numerous applications in paper, food, fermentation, detergent, pharmaceuticals, textile, and distilling industries. Purification is an important prerequisite for any biocatalyst before the development of any enzyme-based effective applications. Cellulase purification is a multistep process selected on the basis of its biochemical and biophysical characteristics such as solubility, charge, size, and hydrophobicity/hydrophilicity. The success of any purification strategy employed for enzyme is evaluated on the basis of its purification fold, recovery percentage, reproducibility, economical feasibility, and time. Mostly, the pre-purification strategies involve fractionation, precipitation and ultrafiltration to attain high enzyme concentrate at the start of the purification process. The highly specific, secondary purification is achieved via chromatographic techniques, such as gel-filtration, ion exchange, adsorption, and affinity chromatography having different types of stationary and mobile phases. Certain unique purification techniques like isoelectric focusing, and electroendosmotic preparative electrophoresis have been also used. This review elaborates about various purification techniques and approaches available for the cellulase enzyme. [ABSTRACT FROM AUTHOR]

Methods of the pretreatment of reeds (grinding, hydrothermal treatment, treatment with acid or alkali solutions, organosolv, deep eutectic solvents) and their effect on the subsequent enzymatic hydrolysis by cellulase and hemicellulase complexes have been studied. Substrates with the highest reactivity were obtained by exposing the reeds to a weakly alkaline deep eutectic solvent (DES) and an alkali solution. The depth of enzymatic hydrolysis of these pretreated substrates was 63 and 59%, and the degree of conversion of polysaccharides (cellulose and hemicellulose) into monosaccharides taking into account the yield of the substrate at the preprocessing stage was 60 and 34%, respectively. After pretreatment of the reeds with acid DES, water steam, water, or a water/organic solution of sulfuric acid, the depth of enzymatic hydrolysis was 45, 25, 20, and 11% and the degree of polysaccharide conversion was 26, 18, 13, and 10%, respectively. The industrial enzyme preparation Agrocell Plus with a predominant content of cellobiohydrolases and endoglucanases was most effective in hydrolyzing the dust fraction of the reed, as was the reed pretreated with a solution of sulfuric acid or DES (acidic or alkaline). The industrial enzyme preparation Agroxil Plus, containing endoxylanase and cellobiohydrolases, was more effective in hydrolyzing the reed after hydrothermal pretreatment or alkali solution. The results of the hydrolysis of the reed pretreated with acidic or weakly alkaline DES under the action of individual (homogeneous) cellulases indicate that in both cases the key enzyme was cellobiohydrolase 1. [ABSTRACT FROM AUTHOR]

Enzyme immobilization has emerged as one of the pivotal technologies in enzyme engineering, offering substantial cost reductions associated with enzyme isolation and utilization. However, efficient catalysis of solid substrates with solid immobilized enzymes remains a challenge, typically exemplified by the hydrolysis of cellulose using immobilized cellulase. In this study, a novel system of reversible release and recycling of cellulase on the surface of low-density polyethylene (LDPE) "hull" was developed, inspired by the operational dynamics of carrier-based aircraft. The reversible formation and disruption of multiple hydrogen bonds between the grafted gelatin molecular chain on the LDPE surface and the modification arm of cellulase (poly (methacrylic acid-propenoic acid; PAA-PMAA) can be achieved through temperature control, thus enabling the reversible release and recycling of modified cellulase molecules on the LDPE surface. Results demonstrated that the release of modified cellulase (PLANE) from the LDPE surface overcame the mass transfer barrier inherent in traditional immobilized enzyme systems for catalyzing insoluble substrates. This was attributed to the dissolution of PLANE in the developed system, rendering its hydrolysis of the insoluble cellulose substrate comparable to that of the free enzyme. Upon completion of the reaction, the PLANE could be reversibly recycled on the surface of the macroscopic LDPE membrane, facilitated by the regeneration of multiple hydrogen bonds. Furthermore, the facile removal of the membrane aided in the convenient recycling of cellulase. Notably, the cellulase molecules in the system retained more than 50% of their biological activity even after 8 batches of reuse, making the process cost-effective. This method addressed the limitations of traditional immobilized enzymes, allowing the catalysis of solid substrates with elevated mass transfer and simultaneous easy recovery, thus standing out as a universal immobilization method. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the cellulase production of four fungi: Aspergillus terreus NIH2624, Aspergillus clavatus NRRL1, Aspergillus versicolor CBS583.65 and Aspergillus phoenicis ATCC3157, under submerged cultivation conditions. When these fungi were cultured in shake flasks using Mandels and Weber's minimal medium with 1% sugarcane bagasse as a carbon source and 1.8 g/L of rice bran extract as a nitrogen source, A. terreus showed maximum cellulase production (filter paper activity (FPase) 3.35 U/mL; carboxymethyl cellulase activity (CMCase) 1.69 U/mL). Consequently, A. terreus was selected for the optimization study for cellulase production. Among the different tested carbon sources, A. terreus showed higher CMCase activity when it was cultivated on delignified sugarcane bagasse (1.64 U/mL) and higher FPase activity on sugarcane straw (7.95 U/mL). Regarding the nitrogen sources, the maximum FPase activity was observed when using rice bran (FPase, 8.90 U/mL) and soybean meal (FPase, 9.63 U/mL). The optimized fermentation medium (minimal medium with delignified sugarcane bagasse and rice bran as carbon and nitrogen sources, respectively) resulted in an enzymatic cocktail mainly composed of xylanases, with a maximum activity of 1701.85 U/mL for beechwood xylan, 77.12 U/mL for endoglucanase and 21.02 U/mL for cellobiohydrolase. Additionally, the enzymatic cocktail showed efficient activities for β-glucosidase, β-xylanase, arabinofuranosidase and lytic polysaccharide monoxygenases (LPMOs). This cellulase enzyme solution has the potential to efficiently hydrolyze lignocellulosic biomass, producing second-generation sugars in biorefineries. [ABSTRACT FROM AUTHOR]

Nitrogen is one of the essential components for cellulase production by fungi and is available in algal proteins. The present study investigates different nitrogen sources such as microalgae extract, yeast extract, peptone, and ammonium nitrate for cellulase production by mono and mix cultures of Trichoderma reesei and Aspergillus niger for the first time. Microalgae are pretreated using different pretreatment strategies to be used as the nitrogen source. The microalgae pretreatment for protein extraction is relatively poorly investigated compared to other protein sources. The prosperous extraction of proteins from mixed microalgae can improved the economic feasibility of the process. Also, the research area on mixed microalgae attracts more attention than traditional pure cultures. The protein extraction results reveal that the highest protein extraction yield (98.1%) was achieved using the sequence of ultrasonic waves and dilute alkaline. Furthermore, results of cellulase production by mono and mix cultures of fungi show that the highest cellulase activity (3.25 U/mL) and the highest reducing sugar production (9.85 g/L) were obtained in the media containing the microalgae extract by mixed fungi culture. This study demonstrates that microalgae can be introduced as a cheap candidate for improvement in cellulase production, which is more economical for industrial usage. Also, the obtained results are of great significance for the further development of such strategies for the modification of fungal culture media for high-quality cellulase production. [ABSTRACT FROM AUTHOR]

The study aims to improve the productivity of cellulase enzyme obtained from bacterial isolates and evaluate enzyme immobilization potential. Previously three isolated bacterial strains, Bacillus velezensis PS09, Bacillus velezensis PS14 and Bacillus paramycoides PS05 were taken from laboratory. Optimization of pH, temperature and carbon sources in culture medium were carried out for maximum cellulase production. The optimum conditions found for maximum cellulase production were 400C at pH 7 with glucose and Carboxymethylcellulose as carbon source. Among bacterial strains, Bacillus velezensis PS09 is the best cellulase producer followed by Bacillus paramycoides PS05 and Bacillus velezensis PS14. The highest enzyme efficiency was shown with 10% concentration and 3.45mm bead size of calcium alginate. [ABSTRACT FROM AUTHOR]

As a large agricultural country, China produces a large number of agricultural and sideline products while harvesting agricultural products every year. Crop straw is one of them. Broom sorghum is a traditional crop in China, which produces a large amount of straw resources every year. These straw resources are placed in the field and cannot be used efficiently. The purpose of this study was to solve the problem of straw utilization of Broom sorghum, one of the main food crops in arid and semi-arid areas of northern China. Broom sorghum is not only a nutritious food crop, its straw is also rich in crude fiber and mineral elements, which has high utilization value. However, due to the high content of lignocellulose in straw, the texture is hard, which limits its digestion and utilization efficiency as feed. In this study, the broom sorghum straw was used as the research object, and the straw raw materials were treated with Lactobacillus plantarum, cellulase and xylanase, respectively. After silage fermentation for 30 d and 60 d, the bags were opened to determine the nutritional quality, fermentation quality, microbial community structure and other indicators. The best fermentation time and additives for broom sorghum straw silage were comprehensively screened to improve the nutritional value of straw and animal production performance. The results showed that the nutritional quality of silage straw increased with the extension of fermentation time. Compared with silage straw after 30 days of fermentation, the nutritional quality and fermentation quality of straw were significantly improved after 60 days of fermentation. Lactobacillus plantarum, cellulase and xylanase could improve the silage performance of broom sorghum straw by improving the microbial community structure in straw, and the effect of cellulase was the best. When cellulase was used in straw at the standard of 20 U/g FM, the content of water-soluble carbohydrates could be significantly increased to 31.35 g/kg FM, and the concentration of lactic acid was also significantly increased to 23.79 g/kg FM. Therefore, in actual production, it is recommended to use cellulase at a dose of 20 U/g FM in broom sorghum silage and open the bag after 60 days of silage fermentation. The results of this study provided a scientific basis for the efficient utilization of broom sorghum straw as feed. [ABSTRACT FROM AUTHOR]

The escalating prevalence of drug-resistant pathogens not only jeopardizes the effectiveness of existing treatments but also increases the complexity and severity of infectious diseases. Escherichia coli is one the most common pathogens across all healthcare-associated infections. Enzymatic treatment of bacterial biofilms, targeting extracellular polymeric substances (EPS), can be used for EPS degradation and consequent increase in susceptibility of pathogenic bacteria to antibiotics. Here, we characterized three recombinant cellulases from Thermothelomyces thermophilus: a cellobiohydrolase I (TthCel7A), an endoglucanase (TthCel7B), and a cellobiohydrolase II (TthCel6A) as tools for hydrolysis of E. coli and Gluconacetobacter hansenii biofilms. Using a design mixture approach, we optimized the composition of cellulases, enhancing their synergistic activity to degrade the biofilms and significantly reducing the enzymatic dosage. In line with the crystalline and ordered structure of bacterial cellulose, the mixture of exo-glucanases (0.5 TthCel7A:0.5 TthCel6A) is effective in the hydrolysis of G. hansenii biofilm. Meanwhile, a mixture of exo- and endo-glucanases is required for the eradication of E. coli 042 and clinical E. coli biofilms with significantly different proportions of the enzymes (0.56 TthCel7B:0.44 TthCel6A and 0.6 TthCel7A:0.4 TthCel7B, respectively). X-ray diffraction pattern and crystallinity index of E. coli cellulose are comparable to those of carboxymethyl cellulose (CMC) substrate. Our results illustrate the complexity of E. coli biofilms and show that successful hydrolysis is achieved by a specific combination of cellulases, with consistent recurrence of TthCel7B endoglucanase. [ABSTRACT FROM AUTHOR]

Cellulase selectively recognizes cellulose surfaces and cleaves their β-1,4-glycosidic bonds. Combining hydrolysis using cellulase and fermentation can produce alternative fuels and chemical products. However, anaerobic bacteria produce only low levels of highly active cellulase complexes so-called cellulosomes. Therefore, we designed hybrid cellulase complexes from 49 biotinylated catalytic domain (CD) and 30 biotinylated cellulose-binding domain (CBD) libraries on streptavidin-conjugated nanoparticles to enhance cellulose hydrolysis by mimicking the cellulosome structure. The hybrid cellulase complex, incorporating both native CD and CBD, significantly improved reducing sugar production from cellulose compared to free native modular enzymes. The optimal CBD for each hybrid cellulase complex differed from that of the native enzyme. The most effective hybrid cellulase complex was observed with the combination of CD6-4 from Thermobifida fusca YX and CBD46 from the Bacillus halodurans C-125. The hybrid cellulase complex/CD6-4-CBD46 and -CD6-4-CBD2-5 combinations showed increased reducing sugar production. Similar results were also observed in microcrystalline cellulose degradation. Furthermore, clustering on nanoparticles enhanced enzyme thermostability. Our results demonstrate that hybrid cellulase complex structures improve enzyme function through synergistic effects and extend the lifespan of the enzyme. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis contributes to obtaining fermentable sugars using pretreated lignocellulose materials for bioethanol generation. Unfortunately, the pretreatment of lignocellulose causes low substrate enzymatic hydrolysis, which is due to the structure changes of lignin to produce main phenolic by-products and non-productive cellulase adsorption. It is reported that modified lignin enhances the speed of enzymatic hydrolysis through single means to decrease the negative effects of fermentation inhibitors or non-productive cellulase adsorption. However, a suitable modified lignin should be selected to simultaneously reduce the fermentation inhibitors concentration and non-productive cellulase adsorption for saving resources and maximizing the enzymatic hydrolysis productivity. Meanwhile, the adsorption micro-mechanisms of modified lignin with fermentation inhibitors and cellulase remain elusive. In this review, different pretreatment effects toward lignin structure, and their impacts on subsequent enzymatic hydrolysis are analyzed. The main modification methods for lignin are presented. Density functional theory is used to screen suitable modification methods for the simultaneous reduction of fermentation inhibitors and non-productive cellulase adsorption. Lignin-fermentation inhibitors and lignin-cellulase interaction mechanisms are discussed using different advanced analysis techniques. This article addresses the gap in previous reviews concerning the application of modified lignin in the enhancement of bioethanol production. For the first time, based on existing studies, this work posits the hypothesis of applying theoretical simulations to screen efficient modified lignin-based adsorbents, in order to achieve a dual optimization of the detoxification and saccharification processes. We aim to improve the integrated lignocellulose transformation procedure for the effective generation of cleaner bioethanol. [Display omitted] • Effects of pretreatment in lignin structure and enzymatic hydrolysis are analyzed. • Lignin modification is the promising enhancement process to bioethanol production. • DFT calculation contributes to screening the suitable lignin modification methods. • Advanced methods to study inhibitors-lignin-cellulase interactions are reviewed. [ABSTRACT FROM AUTHOR]

Soil biota and functions are impacted by various anthropogenic stressors, including climate change, chemical pollution or microplastics. These stressors do not occur in isolation, and soil properties and functions appear to be directionally driven by the number of global change factors acting simultaneously. Building on this insight, we here hypothesize that co-acting factors with more diverse effect mechanisms, or higher dissimilarity, have greater impacts on soil properties and functions. We created a factor pool of 12 factors and calculated dissimilarity indices of randomly-chosen co-acting factors based on the measured responses of soil properties and functions to the single factors. Results show that not only was the number of factors important, but factor dissimilarity was also key for predicting factor joint effects. By analyzing deviations of soil properties and functions from three null model predictions, we demonstrate that higher factor dissimilarity and a larger number of factors could drive larger deviations from null models and trigger more frequent occurrence of synergistic factor net interactions on soil functions (decomposition rate, cellulase, and β-glucosidase activity), which provides mechanistic insights for understanding high-dimensional effects of factors. Our work highlights the importance of considering factor similarity in future research on interacting factors. Soil properties and functions are both affected by many global change factors. Here, the authors use a microcosm experiment to demonstrate that the number of these factors as well as their dissimilarity were important for predicting the impacts of global change factors. [ABSTRACT FROM AUTHOR]

Cellulosic microfibrils in plant cell walls are largely ensheathed and probably tethered by hydrogen-bonded hemicelluloses. Ensheathing may vary developmentally as hemicelluloses are peeled to enable cell expansion. We characterised a simple method to quantify ensheathed versus naked cellulosic surfaces based on the ability to adsorb a radiolabelled ‘cellulose-complementary oligosaccharide’, [³H]cellopentaitol. Filter-paper (cellulose) adsorbed 40% and >80% of aqueous 5 nM [³H]cellopentaitol within ∼1 and ∼20 h respectively. When [³H]cellopentaitol was rapidly dried onto filter-paper, ∼50% of it was desorbable by water, whereas after ∼1 day annealing in aqueous medium the adsorption became too strong to be reversible in water. ‘Strongly’ adsorbed [³H]cellopentaitol was, however, ∼98% desorbed by 6 M NaOH, ∼50% by 0.2 M cellobiose, and ∼30% by 8 M urea, indicating a role for hydrogen-bonding reinforced by complementarity of shape. Gradual adsorption was promoted by kosmotropes (1.4 M Na2SO4 or 30% methanol), and inhibited by chaotropes (8 M urea), supporting a role for hydrogen-bonding. [³H]Cellopentaitol adsorption was strongly competed by non-radioactive cello-oligosaccharides (Cell2–6), the IC50 (half-inhibitory concentration) being highly size-dependent: Cell2, ∼70 mM; Cell3, ∼7 mM; and Cell4–6, ∼0.05 mM. Malto-oligosaccharides (400 mM) had no effect, confirming the role of complementarity. The quantity of adsorbed [³H]cellopentaitol was proportional to mass of cellulose. Of seven cottons tested, wild-type Gossypium arboreum fibres were least capable of adsorbing [³H]cellopentaitol, indicating ensheathment of their microfibrillar surfaces, confirmed by their resistance to cellulase digestion, and potentially attributable to a high glucuronoarabinoxylan content. In conclusion, [³H]cellopentaitol adsorption is a simple, sensitive and quantitative way of titrating ‘naked’ cellulose surfaces. [ABSTRACT FROM AUTHOR]

Various agro-industrial wastes are utilized as fermentation raw materials and are considered promising biorefinery substrates. The search for novel substrates is an ongoing quest, particularly for those residues that do not interfere with the food chain and do not need arable land. Here, a halophytic biomass from Arthrocnemum macrostachyum was utilized as a substrate to produce multienzyme preparation from two endophytic strains of Bacillus sp. TKE1 and TKE4. Initially, a one-factor-at-a-time approach was adopted to investigate the appropriate levels of the variables affecting enzyme production. Consequently, the central composite design was used to optimize the enzymes produced by the two strains. Among the enzymes studied, amylase and xylanase activity were found to have significant R2 values (> 90%) in ANOVA; hence, these were further optimized. Response surface optimization of the enzymes production resulted in the final titers of 4.3 IU mL−1 of amylase and 3.5 IU mL−1 of xylanase by TKE1 while 3.2 IU mL−1 of amylase and 2.9 IU mL−1 of xylanase by TKE4. The SEM analysis revealed the separation of substrate fibers, loosening of the matrix, porous, and increased contact surface. The FTIR results showed significant changes in the lignin-related bands (1518 to 1257 cm−1), changes in the bands for cellulosic component (1635.63 cm−1 and 1608.63 cm−1), starch content (1064.70 cm−1), and β-glycosidic linkage (848.67 and 864.10 cm−1), indicating the degradation of the substrate by the strains. The study concludes that the halophytic biomass from A. macrostachyum can serve as a substrate for industrial enzyme production. [ABSTRACT FROM AUTHOR]

This paper introduces an enzymatic approach to estimate internal mass-transfer resistances during food digestion studies. Cellulase has been used to degrade starch cell walls (where cellulose is a significant component) and reduce the internal mass-transfer resistance, so that the starch granules are released and hydrolysed by amylase, increasing the starch hydrolysis rates, as a technique for measuring the internal mass-transfer resistance of cell walls. The estimated internal mass-transfer resistances for granular starch hydrolysis in a beaker and stirrer system for simulating the food digestion range from 2.2 × 107 m−1 s at a stirrer speed of 100 rpm to 6.6 × 107 m−1 s at 200 rpm. The reaction rate constants for cellulase-treated starch are about three to eight times as great as those for starch powder. The beaker and stirrer system provides an in vitro model to quantitatively understand external mass-transfer resistance and compare mass-transfer and reaction rate kinetics in starch hydrolysis during food digestion. Particle size analysis indicates that starch cell wall degradation reduces starch granule adhesion (compared with soaked starch samples), though the primary particle sizes are similar, and increases the interfacial surface area, reducing internal mass-transfer resistance and overall mass-transfer resistance. Dimensional analysis (such as the Damköhler numbers, Da, 0.3–0.5) from this in vitro system shows that mass-transfer rates are greater than reaction rates. At the same time, SEM (scanning electron microscopy) images of starch particles indicate significant morphology changes due to the cell wall degradation. [ABSTRACT FROM AUTHOR]

The objective of this study was to develop an efficient method for enhancing the production of bioethanol in a single‐reactor system (SRS) by implementing acid–base pretreatment and enzymatic hydrolysis techniques, thereby eliminating differentiation and removal processes. The aim was to establish a process for bioethanol synthesis using hydrolyzed palm oil mill effluent (POME) and a locally sourced cellulase enzyme. The pretreatment and enzymatic hydrolysis methods were successfully optimized, resulting in a maximum yield of reducing sugars of 26.6 g/L (53.14%). To achieve the highest bioethanol yield, fermentation was carried out using both the one‐factor‐at‐a‐time (OFAT) and face‐centered central composite design (FCCCD) approaches. The OFAT approach was employed to obtain the maximum bioethanol production, which yielded 6.75% v/v of bioethanol from the hydrolyzed POME using the same bioreactor. In the case of the FCCCD process, the optimal conditions led to a bioethanol production of 7.64% v/v during the fermentation stage. Kinetic analyses of the bioethanol produced revealed a specific growth rate (μ) of 0.198 h−1 and a specific product formation rate (qp) of 0.239 h−1 after 3 days of fermentation. These findings highlight a promising strategy for efficient management of POME through the production of biofuels, which could contribute to the economic growth of the country. [ABSTRACT FROM AUTHOR]

Bamboo is a perennial rapid-growing plant that is given preference for renewable biosources for biofuels and bio-based chemical conversion. Bamboos are rich in cellulose and have highly recalcitrant biomass due to high lignin. Bamboo is abundantly available in Northeastern India and can be utilized as a feedstock biofuels. Here, we evaluated the pretreatment of bamboo residues Dendrocalamus strictus with different concentrations of alkali, hydrogen peroxide, and alkaline hydrogen peroxide and its influence on biomass digestibility for enhancement of sugar recovery with Celic C cellulase enzyme blend. Enzymatic hydrolysis data indicated untreated raw biomass showed a digestibility of 40% after 48 h of incubation. The biomass pretreated with alkali showed a maximum digestibility of 61% obtained from 10% loaded with 0.5% w/v NaOH. Pretreatment of the bamboo with H2O2 shows a maximum digestibility of 75% from biomass loaded with 1% w/v of H2O2. Combinational pretreatment of alkaline hydrogen peroxide showed a maximum efficiency of biomass digestibility of 83% attained from biomass loaded with 1% w/v NaOH-H2O2. Crystallinity index (CrI) analysis showed that CrI increased from 64% to 70.75% in pretreated biomass. FTIR and SEM analysis show changes in functional groups, morphology, and surface of biomass in pretreated biomass. Compositional analysis shows that 68% of lignin removal is obtained from alkaline hydrogen peroxide pretreatment. Cellulose content increased from 52% to 65%, and hemicellulose decreased from 18.6% to 8.6%. Results indicated that the potential possibility of bamboo waste biomass as feedstock for biorefinery products and alkaline hydrogen peroxide pretreatment methods is an efficient strategy for sugar recovery for bioethanol production. [ABSTRACT FROM AUTHOR]

The utilisation of enzymes in the industry has brought numerous benefits and advantages to production processes. Enzymes serve as biocatalysts, efficiently catalyzing reactions and hydrolysis in biochemical processes. However, there are challenges in applying enzymes in the industry, particularly concerning enzyme stability. The obstacle encountered in the production processes involving industrial enzyme applications is the low stability of enzymes when used at high temperatures. Heat-sensitive enzymes undergo damage or denaturation. Thermophilic microorganisms are chosen because they hold the potential to produce thermophilic enzymes. The thermophilic enzymes exhibit better heat stability compared to other enzymes, making them an effective alternative for future industrial production processes. This study aims to isolate thermotolerant bacteria from Nglimut Hot Spring sediment, screen for cellulase- and amylase-producing isolates, and molecularly identify the best isolate using 16S rRNA barcode. The results show that 22 bacterial isolates were found in the sediment of a hot spring; TS-14 was the best isolate in producing amylase, with the highest average amylolytic index of 2.38, whereas TS-15 had the highest cellulolytic index of 2.11. Based on 16S rRNA identification, TS-14 showed an homological identity of 79% with Bacillus amyloliquefaciens, while TS-15 had a 100% homological identity with Bacillus licheniformis. These results were important as the first step of screening bacterial potential to produce thermophilic enzymes that could be applied in the downstream processing in future industrial and biotechnology companies. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the in silico genomic characteristics of five species of the genus Planotetraspora: P. kaengkrachanensis, P. mira, P. phitsanulokensis, P. silvatica, and P. thailandica, with a view to their application in therapeutic research. The 16S rRNA comparison indicated that these species were phylogenetically distinct. Pairwise comparisons of digital DNA-DNA hybridization (dDDH) and OrthoANI values between these studied type strains indicated that dDDH values were below 62.5%, while OrthoANI values were lower than 95.3%, suggesting that the five species represent distinct genomospecies. These results were consistent with the phylogenomic study based on core genes and the pangenome analysis of these five species within the genus Planotetraspora. However, the genome annotation showed some differences between these species, such as variations in the number of subsystem category distributions across whole genomes (ranging between 1979 and 2024). Additionally, the number of CAZYme (Carbohydrate-Active enZYme) genes ranged between 298 and 325, highlighting the potential of these bacteria for therapeutic research applications. The in silico physico-chemical characteristics of cellulases from Planotetraspora species were analyzed. Their 3D structure was modeled, refined, and validated. A molecular docking analysis of this cellulase protein structural model was conducted with cellobiose, cellotetraose, laminaribiose, carboxymethyl cellulose, glucose, and xylose ligand. Our study revealed significant interaction between the Planotetraspora cellulase and cellotetraose substrate, evidenced by stable binding energies. This suggests that this bacterial enzyme holds great potential for utilizing cellotetraose as a substrate in various applications. This study enriches our understanding of the potential applications of Planotetraspora species in therapeutic research. [ABSTRACT FROM AUTHOR]

Leaves play a crucial role as ornamental organs in Spathiphyllum, exhibiting distinct differences across various Spathiphyllum varieties. Leaf development is intricately linked to processes of cell proliferation and expansion, with cell morphology often regulated by plant cell walls, primarily composed of cellulose. Alterations in cellulose content can impact cell morphology, subsequently influencing the overall shape of plant organs. Although cellulases have been shown to affect cellulose levels in plant cells, genetic evidence linking them to the regulation of leaf shape remains limited. This study took the leaves of Spathiphyllum 'Mojo' and its somatic variants as the research objects. We screened four cellulase gene family members from the transcriptome and then measured the leaf cellulose content, cellulase activity, and expression levels of cellulase-related genes. Correlation analysis pinpointed the gene SpGH9A3 as closely associated with leaf shape variations in the mutant. Green fluorescent fusion protein assays revealed that the SpGH9A3 protein was localized to the cell membrane. Notably, the expression of the SpGH9A3 gene in mutant leaves peaked during the early spread stage, resulting in smaller overall leaf size and reduced cellulose content upon overexpression in Arabidopsis. [ABSTRACT FROM AUTHOR]

A thermo-alkali stable cellulase from Geobacillus sp. TP-1 was isolated from Tapovan hot spring soil sample. The BLASTn sequence analysis of 16S rRNA sequence revealed that the isolate belonged to the Geobacillus genus and shared the highest degree of sequence similarity (99.43%) with the different strains of Geobacillus subterraneus. The neighbour joining method of multiple sequence alignment revealed that the 16S rRNA sequence of Geobacillus sp. TP-1 shows maximum similarity with Geobacillus stearothermophilus strain S_YE6-1017-022. One-Factor-At-a-Time analysis was used to optimize the carbon source, nitrogen source, pH, temperature, inoculum size and growth profile with respect to cellulase production. When compared to un-optimized basal media, optimised medium increased cellulase production by around 3.6 times. The Plackett Burman factorial design was employed to identify the critical medium components influencing cellulase activity and temperature was determined to have a significant effect on overall cellulase production. The current strain was capable of utilising lignocellulosic waste as an alternative carbon source. The use of sugarcane molasses and wheat bran as carbon sources resulted in a significant increase (~ 7.2 fold) in cellulase production in the current study, indicating the bacterium's potential for valorising lignocellulosic biomass into value-added products, which encourages its use in lignocellulosic-based bio refineries. [ABSTRACT FROM AUTHOR]

Corn cobs consist primarily of a lignocellulosic material comprising hemicellulose, cellulose, and lignin in a crystalline state, which is resistant to microbial saccharification. Bioethanol production from corn cobs has rarely been attempted, especially using chemical pretreatment methods. The present study deals with the production and purification of fungal (Phanerochaete chrysosporium MTCC 787 and Pleurotus florida PAU 22‐01) extracellular ligninolytic enzymes – lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac) – followed by their utilization for the biological pretreatment of corn cobs along with saccharification using commercial cellulase. Crude LiP, MnP, and Lac demonstrated specific activity of 2.23, 2.1, and 2.63 U/mg, respectively. The one‐step purification of crude enzyme using diethyl amino ethyl (DEAE) cellulose ion exchange chromatography resulted in 11.3, 10.1 and 8.62‐fold purification of LiP, MnP and Lac activity, respectively, with corresponding specific activity of 25.1 U/mg (LiP), 21.2 U/mg (MnP) and 22.7 U/mg (Lac) in the partially purified ligninozymes. Using the latter, biological pretreatment of 2.5 g corn cobs in a reaction volume of 30 mL containing approximately 200 units of Lac, Lip and MnP enzymes (in phosphate buffer, pH 6) resulted in a maximum of 78.4% delignification with a saccharification efficiency of 97.1% using commercial cellulases. [ABSTRACT FROM AUTHOR]

The high cost of cellulolytic enzyme complexes (CECs) has been a significant impediment to the commercial production of bioproducts from lignocellulose biomass. This study aimed to develop a cost‐effective CEC derived from Penicillium ucsense (former Penicillium echinulatum), utilizing diverse forms of pretreated sugarcane bagasse as the primary carbon/inductor source. Among the different pretreatments used, the hydrothermal pretreatment followed by NaOH delignification (BHD) produced higher FPase and xylanase activities (4.5 FPU mL–1 and 120 IU mL–1) in bioreactor experiments at 20 g BHD L–1 initial concentration. A batch‐mode assay conducted across a range of initial carbon source (5 to 60 g L–1) confirmed the highest FPase activity (4.0 to 5.0 FPU mL–1 at 120 h), in the range of 20–40 g BHD L–1. During these assays the agitation rate, controlled by dissolved O2, tended to stabilize at lower levels, indicating substrate limitation. Conversely, higher initial carbon source concentrations led to an excess of glucose, likely triggering carbon catabolite repression and inhibiting cellulase production. This insight prompted the development of a controlled pulsed fed‐batch strategy, resulting in FPase activity of 11 FPU mL–1 at 220 h using 90 g L–1 BHD controlled fed into the bioreactor. An enzymatic hydrolysis procedure using the generated CEC was also optimized using a central composite rotational design (CCRD). The optimized enzyme hydrolysis conditions achieved a reducing sugar concentration of 80.9 g L–1 in 48 h using 170 g L–1 of BHD as the substrate at a ratio of 15 FPU of enzyme substrate per g of BHD. A preliminary economic assessment demonstrated that, for a first‐ and second‐generation (1G + 2G) ethanol biorefinery, the cost contribution of enzymes would be about US$0.2/L of biofuel. In conclusion, an efficient and highly productive procedure was developed successfully for the production of a CEC. It was particularly effective for the enzymatic hydrolysis of pretreated sugarcane bagasse. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass, the most abundant natural resource on earth, can be used for cellulosic ethanol production but requires a pretreatment to improve enzyme access to the polymeric sugars while obtaining value from the other components. γ‐Valerolactone (GVL) is a promising candidate for biomass pretreatment since it is renewable and bio‐based. In the present work, the effect of a pretreatment based on GVL on the enzymatic saccharification of white birch was evaluated at a laboratory scale and the importance of the washing procedure for the subsequent saccharification was demonstrated. Both the saccharification yield and the production of cellulosic ethanol were higher using a noncommercial enzyme crude from Talaromyces amestolkiae than with the commercial cocktail Cellic CTec2 from Novozymes. Furthermore, the production of extracellular cellulases by T. amestolkiae has been optimized in 2 L bioreactors, with improvements ranging from 40% to 75%. Finally, it was corroborated by isoelectric focus that optimization of cellulase secretion by T. amestolkiae did not affect the pattern production of the main β‐glucosidases and endoglucanases secreted by this fungus. [ABSTRACT FROM AUTHOR]

Reed sawdust is a kind of paper mill waste with high cellulose and hemicellulose content. To promote the rational use of resources, it is essential to make full use of waste resources and transform them into new values. In this work, reed sawdust was pretreated with liquid hot water (LHW) at 170 °C for 30 min. A total of 39.00 g/L glucose was obtained after enzymatic saccharification of cellulose at 50 °C, 20 FPU/g-reed sawdust cellulase, 25% (w/v) reed sawdust, in 5 replenishments. When the fermentation was performed 96 h, the medium contained xylo-oligosaccharides (XOS) 11.74 g/L and biomass 15.21 g/L, in which lipid was 4.14 g/L. After spray drying, feed additives containing 29.17% XOS and 10.29% docosahexaenoic acid (DHA) can be prepared. In particular, the hemicellulose and cellulose in reed sawdust are creatively used at the same time without separation, which greatly reduces the cost of purification in traditional processes and provides a new way for the high-value transformation of sawdust resources. [ABSTRACT FROM AUTHOR]

Sawdust, a major waste product of the forestry industry, is accumulating along the Lagos Lagoon in Lagos, Nigeria, without it being effectively managed. Besides its use in manufacturing sound-absorbing boards to reinforce concrete beams and for energy purposes, its potential as a renewable energy source and feedstock for bio-product development has not yet been realized. Cellulose, a glucose biopolymer and structural component of cellulose can be hydrolyzed by a hydrolytic enzyme known as cellulase. During the process, the enzyme breaks the B-1,4-glucosidic bond, which keeps the glucose units together, and by acting on this bond, numerous glucose units are released. As part of sawdust, the cellulose molecule is not freely available for the degradation action of the cellulase enzyme as it is strongly associated with lignin, which acts as bio-glue, keeping cellulose and hemicellulose together. Delignification is an effective technique that was used to make the sawdust from ten different trees along the Lagos Lagoon in Nigeria more susceptible to saccharification by cellulase isolated from the fungus Aspergillus niger. Delignified and non-delignified sawdust masses between 2 mg and 10 mg were incubated with the A. niger cellulase solution (2 mg.mL-1), whereafter, the amount of sugar produced by the cellulase action was determined. The percentage saccharification of each sawdust material was also linked with the amount of sugar produced during cellulase action. From these investigations was concluded that delignification increased sugar production when almost all the masses of different sawdust materials were degraded. It was also observed that the ratio of sawdust mass to enzyme concentration is an important variable that influences the effectiveness of the saccharification process. The percentage saccharification of the various sawdust materials was also determined, and it indicated that the highest percentage of saccharification was not obtained when the highest amount of sawdust was degraded, producing the highest amount of sugar. The saccharification of sawdust could contribute to the development of renewable energy sources and feedstock for bioproduct development. The process is, however, not that straightforward as variables such as the type of cellulase enzyme, pretreatment of the cellulose substrate, and optimizing of cellulase to cellulose ratio are a few that need to be optimized for the process to be effective in terms of glucose production. [ABSTRACT FROM AUTHOR]