Production Of Cellulolytic Enzymes Research Articles

Valorization of agricultural by-product for cleaner and sustainable production of microbial pigments and cellulolytic enzymes in a zero-waste approach

This work presents a zero-waste concept for the valorization of banana peel into Monascus value-added metabolites, such as pigments and cellulolytic enzymes, and for evaluation of the feasibility of treated peel as a promising source for animal feedstuff. M. purpureus YRU01 exhibited satisfactory pigment and cellulolytic enzyme production in solid-state fermentation. Particularly, repeated solid-state fermentation of non-sterile peel with 90% substrate replacement was effective in offering high recovery of pigments, xylanase, and cellulase (7.19-, 31.19-, and 92.62-fold higher than those of solid-state fermentation, respectively). The LC/MS profile of fermented peel provided important evidence of fungal metabolites (>100 metabolites) for understanding and evaluating the fermentation. Moreover, citrinin-related mycotoxin fragments were not found. The treated peel had high carbohydrate, neutral detergent fiber, and acid detergent fiber contents, but low protein content, indicating its potential to be used as a roughage in animal feed.

Production of Cellulolytic Enzymes by Paecilomyces TP08 Using Grape Stalk and Wheat Bran as Substrates in Solid State Culture

Objective: The objective of this study is to investigate the use of grape stems and wheat bran as substrates in solid state fermentation, for the production of cellulolytic enzymes using the fungus Paecilomyces TP08 sp. Theoretical Framework: In grape production, driven by increased consumption and exports, by-products represent 30% of the total volume of grapes processed for wine, requiring efficient management to ensure sustainability. Method: The methodology adopted for this research involves solid-state cultivation, with a substrate made up of 50% grape stems and 50% wheat bran, with samples taken every 24 hours. Each sample taken went through a filtration process, followed by enzyme activity analysis using the DNS method. Results and Discussion: The results obtained showed that the cultivation with the association of wheat bran and grape stalks presented good total cellulase activity during the process, value of 0.846 U/g in 144h, followed by the activity of 0.663U/g observed in 24h. Research Implications: The practical and theoretical implications of this research are discussed, providing insights into how the results can be applied or influence practices in the field of industrial biotechnology. These implications could cover the food, textile and pharmaceutical industries. Originality/Value: This study contributes to the literature by associating grape stalks with wheat bran for the production of fungal enzymes. The relevance and value of this research are evidenced by the use of an innovative substrate (grape stalks) associated with a conventional substrate (wheat bran) for induction of the microorganism little used in the literature for enzyme production.

Combinational manipulation of transcription factors, CreA and ClbR, is a viable strategy to improve cellulolytic enzyme production in Aspergillus aculeatus

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 ΔcreA 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 ΔcreA 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.

Optimization of Lignocellulosic Enzyme production by Microbial Strains: Study of Kinetics and Environmental Influences

In the context of valorizing lignocellulosic biomass for biofuel production a mixture of forest residues (FW) and aromatic-medicinal plant wastes (AMPW) was considered in this study to assess its ability to support the production of cellulolytic enzymes by Aspergillus niger, Trichoderma longibrachiatum and Zymomonas mobilis. The residue mixture promoted growth and cellulase production by the microbial strains after 6 days of incubation. Enzymatic activity was determined using filter paper activity (FPase) and endoglucanase carboxymethylcellulase (CMase) assays. Optimization of enzymatic activity was investigated at pH levels (2, 4, 6, 8), various temperatures (22°C, 30°C, 37°C, 45°C) and different inoculum rates (1.5 × 107, 2 × 107 and 2.5 × 107 spores per gram of substrate). Maximum enzymatic activity was observed in Aspergillus niger with FPase and CMCase yields of 23.12 ± 0.1 and 29.78 ± 0.15 U/gds respectively. The highest enzymatic activity was recorded at temperatures of 30°C and 37°C, pH levels of 4 and 6 and with an inoculum rate of 2.5 × 107. The selection of the strain and the optimization of operational conditions are crucial for efficient enzymatic production in the context of biorefinery.

Fungal co-culture enabled co-fermentation of food waste for production of endoglucanase enzyme

The primary scenarios of biochemical industries include diverse applications with high demand and the costly manufacturing of microbial cellulolytic enzymes. Using these enzymes to turn cellulosic waste into fuel is one of the prime applications of these enzymes to produce green fuel. Nevertheless, low production and weak functional abilities make these enzymes expensive and technically non-viable. This study presents multifactor bioprocess approaches to enhance cellulolytic enzyme production and efficiency using a low-cost strategy. Co-fermentation of pea pods (PPs) and potato peel (PP) wastes as food wastes has been conducted for solid-state fermentation (SSF) using fungal strain-based co-culture. To set the SSF, the nutrient medium and moisture balance of SSF have been maintained using an extract of PPs and PP waste, which are found to be rich in sugar and starch composition. Starch may function as a natural inducer in the SSF process to alleviate enzyme production in the presence of sugar composition. At 37 oC and pH 5.0, a maximum of 2.4 U/mL FPA (filter paper activity) has been produced at a substrate ratio of 4:04 (PPs:PP) using 50% of the moisture content on day 5 of the harvesting period. Additionally, 24.7 IU/mL of CMCase (carboxymethyl cellulase) in day 8 and 18.8 IU/mL of BGL (β-Glucosidase) in day 7 have been obtained. A temperature of 37 oC was found to be optimal, while a pH range of 5.0–9.0 was noticed to be optimal for maximum CMCase activity. Thus, the study may provide a sustainable approach to valorizing domestic solid food waste for the economic production of hydrolytic enzymes.

Co-fermentation of acid treated coconut wastes using mixed Bacillus cultures for enhanced production of extracellular enzymes: Application in bioconversion of raw coconut fibers

Higher cost of production and functioning efficiency are the two most important aspects of cellulolytic enzymes, as they directly affect the bioconversion of cellulosic waste into fermentable sugars. Thus, the current study aims to investigate the production of cellulolytic enzymes from low-cost waste biomass for use in the sustainable hydrolysis of biomass to yield fermentable sugars. Since coconut waste is a major contributor to biodegradable waste, two different parts of coconut, including the hard shell of coconut (CS) and the fibers of the shell (FS), have been used for enzyme production as feedstock. Further, enzyme production has been carried out on co-fermentative and acid-pretreated coconut substrates (CS and FS) at different quantities using mixed bacterial cultures. Following this, a crude enzyme with a maximum 20 U/gds FPA, 62 U/gds BGL, and 167 U/gds EG has been produced by mixed Bacillus cultures under co-fermentation of 0.5 % acid-pretreated CS and FS substrates at a quantity of 5:5 (g:g) at 35 oC and pH 5.0. The crude enzyme showed its thermal stability for 16 h at 50 oC and released ∼34 g/L of sugars from the hydrolysis of untreated FS biomass in 24 h. This work may have significant applications in the area of biomass-based biorefining as well as waste management.

The transcription factor STE12 influences growth on several carbon sources and production of dehydroacetic acid (DHAA) in Trichoderma reesei

The filamentous ascomycete Trichoderma reesei, known for its prolific cellulolytic enzyme production, recently also gained attention for its secondary metabolite synthesis. Both processes are intricately influenced by environmental factors like carbon source availability and light exposure. Here, we explore the role of the transcription factor STE12 in regulating metabolic pathways in T. reesei in terms of gene regulation, carbon source utilization and biosynthesis of secondary metabolites. We show that STE12 is involved in regulating cellulase gene expression and growth on carbon sources associated with iron homeostasis. STE12 impacts gene regulation in a light dependent manner on cellulose with modulation of several CAZyme encoding genes as well as genes involved in secondary metabolism. STE12 selectively influences the biosynthesis of the sorbicillinoid trichodimerol, while not affecting the biosynthesis of bisorbibutenolide, which was recently shown to be regulated by the MAPkinase pathway upstream of STE12 in the signaling cascade. We further report on the biosynthesis of dehydroacetic acid (DHAA) in T. reesei, a compound known for its antimicrobial properties, which is subject to regulation by STE12. We conclude, that STE12 exerts functions beyond development and hence contributes to balance the energy distribution between substrate consumption, reproduction and defense.

Investigation of the presence and enzymatic activity of fungi in stored corn (Zea mays L.) and soybean [Glycine max (L.) Merrill] grains

Soy [Glycine max (L.) Merrill] and corn (Zea mays L.) are important crops in Brazilian agribusiness. When stored improperly, these grains are susceptible to insects and microorganisms. Among the microorganisms capable of causing grain deterioration, fungi stand out. Despite the harm associated with fungi, they are biotechnologically appreciable due to their potential ability to produce hydrolytic enzymes, such as cellulases and proteases. Fungal hydrolytic enzymes have been applied in various processes in the food, textile, and detergent production industries, among others. The objective of this study was to verify the presence of fungi in samples of corn and soybean grains under storage conditions and characterize them regarding the production of cellulolytic and proteolytic enzymes. Among the results, there was a greater quantity and variety of filamentous fungi (35 morphotypes) in association with the grains evaluated, than of yeasts (three morphotypes). Representatives of the genera Aspergillus spp., Curvularia sp., and Penicillium spp. were detected, corroborating previous reports in the literature. Filamentous fungi that tested positive for cellulase production had an enzyme ratio index (ERI) varying between 1.06 and 2.57 (mean ± standard deviation = 1.37 ± 0.48), while for proteolytic activity, only the fungi isolated from soybean tested positive, with ERI (mean ± standard deviation) = 1.21 ± 0.01. Although the taxonomy of the isolates in this study has not been completely elucidated, it is possible to state that these fungi are promising for producing hydrolytic enzymes, with potential for use in the development of products and/or biotechnological processes.

Enhancement of cellulolytic enzyme production from intrageneric protoplast fusion of Aspergillus species and evaluating the hydrolysate scavenging activity

BackgroundLignocellulosic biomass provides a great starting point for the production of energy, chemicals, and fuels. The major component of lignocellulosic biomass is cellulose, the employment of highly effective enzymatic cocktails, which can be produced by a variety of microorganisms including species of the genus Aspergillus, is necessary for its utilization in a more productive manner. In this regard, molecular biology techniques should be utilized to promote the economics of enzyme production, whereas strategies like protoplast fusion could be employed to improve the efficacy of the hydrolytic process.ResultsThe current study focuses on cellulase production in Aspergillus species using intrageneric protoplast fusion, statistical optimization of growth parameters, and determination of antioxidant activity of fermentation hydrolysate. Protoplast fusion was conducted between A. flavus X A. terreus (PFFT), A. nidulans X A. tamarii (PFNT) and A. oryzae X A. tubingensis (PFOT), and the resultant fusant PFNT revealed higher activity level compared with the other fusants. Thus, this study aimed to optimize lignocellulosic wastes-based medium for cellulase production by Aspergillus spp. fusant (PFNT) and studying the antioxidant effect of fermentation hydrolysate. The experimental strategy Plackett-Burman (PBD) was used to assess how culture conditions affected cellulase output, the best level of the three major variables namely, SCB, pH, and incubation temperature were then determined using Box-Behnken design (BBD). Consequently, by utilizing an optimized medium instead of a basal medium, cellulase activity increased from 3.11 U/ml to 7.689 U/ml CMCase. The following medium composition was thought to be ideal based on this optimization: sugarcane bagasse (SCB), 6.82 gm; wheat bran (WB), 4; Moisture, 80%; pH, 4; inoculum size, (3 × 106 spores/ml); and incubation Temp. 31.8 °C for 4 days and the fermentation hydrolysate has 28.13% scavenging activities.ConclusionThe results obtained in this study demonstrated the significant activity of the selected fusant and the higher sugar yield from cellulose hydrolysis over its parental strains, suggesting the possibility of enhancing cellulase activity by protoplast fusion using an experimental strategy and the fermentation hydrolysate showed antioxidant activity.

Cellulolytic Aerobic Bacteria Isolated from Agricultural and Forest Soils: An Overview.

This review provides insights into cellulolytic bacteria present in global forest and agricultural soils over a period of 11 years. It delves into the study of soil-dwelling cellulolytic bacteria and the enzymes they produce, cellulases, which are crucial in both soil formation and the carbon cycle. Forests and agricultural activities are significant contributors to the production of lignocellulosic biomass. Forest ecosystems, which are key carbon sinks, contain 20-30% cellulose in their leaf litter. Concurrently, the agricultural sector generates approximately 998 million tons of lignocellulosic waste annually. Predominant genera include Bacillus, Pseudomonas, Stenotrophomonas, and Streptomyces in forests and Bacillus, Streptomyces, Pseudomonas, and Arthrobacter in agricultural soils. Selection of cellulolytic bacteria is based on their hydrolysis ability, using artificial cellulose media and dyes like Congo red or iodine for detection. Some studies also measure cellulolytic activity in vitro. Notably, bacterial cellulose hydrolysis capability may not align with their cellulolytic enzyme production. Enzymes such as GH1, GH3, GH5, GH6, GH8, GH9, GH10, GH12, GH26, GH44, GH45, GH48, GH51, GH74, GH124, and GH148 are crucial, particularly GH48 for crystalline cellulose degradation. Conversely, bacteria with GH5 and GH9 often fail to degrade crystalline cellulose. Accurate identification of cellulolytic bacteria necessitates comprehensive genomic analysis, supplemented by additional proteomic and transcriptomic techniques. Cellulases, known for degrading cellulose, are also significant in healthcare, food, textiles, bio-washing, bleaching, paper production, ink removal, and biotechnology, emphasizing the importance of discovering novel cellulolytic strains in soil.

Extraction of Cellulases Produced through Solid-State Fermentation by Trichoderma reesei CCT-2768 Using Green Coconut Fibers Pretreated by Steam Explosion Combined with Alkali

The industrial processing of coconut to produce valuable foods, such as water and milk, generates large volumes of waste, especially the fruit shell. Despite this, material can be used in bioprocess applications, e.g., the production of enzymes, its recalcitrance hinders the cultivation of microorganisms, and low productivity is usually achieved. In this study, the production of cellulolytic enzymes through solid-state fermentation (SSF) and their extraction was investigated using the green coconut fiber pretreated by steam explosion, followed by alkali. The fungus Trichoderma reesei CCT-2768 was cultivated, using an experimental design, to study the effect of the water activity and the amount of biomass in the reactor. The combination of the pretreatment strategies yielded more porous biomass, with less hemicellulose (5.38%, compared to 10.15% of the raw biomass) and more cellulose (47.77% and 33.96% in the pretreated and raw biomasses, respectively). The water activity significantly affected the production of cellulases, with maximum activity yielded at the highest investigated value (0.995). Lastly, the extraction of the enzymes from the cultivation medium was studied, and a 9 g/L NaCl solution recovered the highest CMCase and FPase activities (5.19 and 1.19 U/g, respectively). This study provides an important contribution to the valorization of the coconut residue through (i) the application of the steam explosion technology to optimize the production of cellulases using the SSF technology and (ii) their extraction using different solvents.

Determination of cellulolytic potentials of <i>Aspergillus</i> species isolated from central waste dump site of Nile University of Nigeria

A large number of microorganisms are capable of degrading cellulose but only a few of these microorganisms produce significant quantities of enzymes capable of completely hydrolyzing cellulose. Fungi are the main cellulase-producing microorganisms. This study was aimed to determine the cellulolytic potentials of Aspergillus species isolated from the central waste dump site of Nile University of Nigeria. In this study, fungal species were isolated from soil samples obtained from waste dump site using pour plate technique. The isolates were characterized using cultural and morphological features as well as microscopic examination. Aspergillus flavus, Aspergillus niger, and Aspergillus terreus, which were isolated were further screened on carboxymethylcellulose agar for their ability to degrade cellulose. Screening of fungal isolates was performed by plate method. Cellulolytic fungi were evaluated after 5 days for the production of cellulolytic enzymes by staining with 1% Congo red. The diameter of clear zone on fungal plates, gave an approximate indication of cellulase activities. Aspergillus niger had a zone of clearing of 25.50 mm while Aspergillus flavus had 18.50 mm. Aspergillus terreus did not show any cellulolytic activity. Aspergillus niger had the highest occurrence rate of 50%. Aspergillus flavus and Aspergillus terreus both had 25% occurrence rate.

Different Putative Methyltransferases Have Different Effects on the Expression Patterns of Cellulolytic Genes.

Putative methyltranferase LaeA and LaeA-like proteins, conserved in many filamentous fungi, regulate fungal growth, development, virulence, the biosynthesis of secondary metabolites, and the production of cellulolytic enzymes. Penicillium oxaliucm is a typical fungus that produces cellulolytic enzymes. In this study, we reported the biological function of eight putative methyltransferases (PoMtr23C/D/E/F/G/H and PoMtr25A/B) containing a methyltransf_23 or methyltransf_25 domain, with a focus on their roles in the production of cellulolytic enzymes. In P. oxalicum, various methyltransferase genes displayed different transcriptional levels. The genes Pomtr23C and Pomtr25A exhibited high transcriptional levels, while Pomtr23D/E/F/G/H and Pomtr25B were transcribed constantly at low levels. The gene deletion mutants (Δmtr23C/D/E/F/G/H and Δmtr25A/B) were constructed. Various mutants have different patterns in cellulolytic enzyme production. Compared to the WT, the largest increase in filter paper activity (FPA, indicating total cellulase activity) was observed in the Δmtr23G mutant, the only mutant with a cellulolytic halo surrounding the colony. Three mutants (Δmtr23C/D and Δmtr25A) also showed increased cellulolytic enzyme production. The Δmtr23E and Δmtr25B mutants displayed decreased FPA activity, while the Δmtr23F and Δmtr23H mutants displayed similar patterns of cellulolytic enzyme production compared with the WT. The assay of transcriptional levels of cellobiohydrolase gene Pocbh1 and β-1,4-endoglucanase Poeg1 supported that higher cellulolytic gene transcription resulted in higher production of cellulolytic enzymes, and vice versa. The transcriptional levels of two transcription factors, activator XlnR and repressor CreA, were measured. The high transcription level of the PoxlnR gene in the Δmtr23D mutant should be one reason for the increased transcription of its cellulolytic enzyme gene. Both XlnR and CreA transcriptional levels increased in the Δmtr23G mutant, but the former showed a more significant increase than the latter, indicating that the activation effect predominated. The PoMtr25A is localized in the nucleus. The catalytic subunit SNF2 of the SWI/SNF chromatin-remodeling complex was found as one of the interacting proteins of PoMtr25A via tandem affinity purification coupled with mass spectrometry. PoMtr25A may affect not only the transcription of repressor CreA but also by recruiting SWI/SNF complexes that affect chromatin structure, thereby regulating the transcription of target genes.

Date seed waste derived nanocatalyst and its application in production of hydrolytic enzyme, fermentative sugars and biohydrogen

Biofuel production from cellulosic biomass is a promising approach; however, the cost-intensive utilization of cellulolytic enzymes is a major roadblock to economic production. This study reports the preparation of a nanocatalyst using date seed and evaluates the impact of nanocatalysts on cellulolytic enzyme production using solid-state fermentation of date pulp waste through bacterial co-cultivation. Under optimized conditions, 30 IU/gds filter paper activity is produced in the presence of 2 mg of nanocatalyst. Cellulase showed thermal stability at 50 °C and pH 7 up to 10 h in the presence of nanocatalyst, and it produced 32.31 g/L glucose through the hydrolysis of acidic-pretreated date seeds in 24 h. Subsequently, 1788 mL/L of cumulative H2 in 24 h through cocultured dark fermentation could be produced. The approach presented in this study can be effective for multiple value additions, including nanocatalyst preparation, cellulase enzyme, and biohydrogen production.

Al2(SO4)3 alters the antioxidant mitochondrial metabolism of Botritys cinerea and optimizes the production of cellulose and oxidative degrading enzymes

The enzymes produced by pathogenic fungi, especially Botritys cinerea, deserve specific attention due to the diversity of their applications, mainly in biofuel production, food processing, and the pharmaceutical industry. Thus, this work used Al2(SO4)3 as a stressor in order to evaluate if the stress levels caused by the concentrations of 100, 250, 500, and 1000 ppm were sufficient to increase the production of hydrolytic cellulolytic enzymes (FPase, CMCase, Avicelase, β-glucosidase, xylanase) and oxidative (laccase and manganese peroxidase). The study also evaluated the stress levels in previously treated mycelia of B. cinerea and whether they corresponded to the different states of mitochondrial respiration. Our study indicates that Al2(SO4)3 increased the production of cellulolytic and oxidative enzymes in all concentrations in a dose-dependent manner and that Al2(SO4)3 alters the mitochondrial respiratory rate, with lower ATP productions, indicating that less-coupled mitochondria were obtained and that this may be due to the increase of oxidative stress. Thus, it is plausible to suggest the use of Al2(SO4)3 in the production of cellulolytic enzymes, which could be used in the hydrolysis stage of second-generation ethanol production processes, as it reduces the time required for enzymatic expression applications in industrial processes.

Cellulase and Xylanase Production by a Newly Isolated Penicillium crustosum Strain under Solid-State Fermentation, Using Water Hyacinth Biomass as Support, Substrate, and Inducer

Cellulase and xylanase have been widely studied for bioconversion processes and applied in various industries. The high cost of these enzymes remains to be the major bottleneck for large-scale commercial application of lignocellulosic biorefinery. The use of agroindustrial residues and weeds as fermentation substrates is an important strategy to increase cellulolytic enzymes production and reduce costs. Penicillium crustosum was newly isolated and selected to study its enzyme production during solid-state fermentation (SSF). Natural and pretreated water hyacinth (WH) biomass was used as support, substrate and inducer of cellulases and xylanases. Thermochemical pretreatments of WH biomass at 121 °C and sulfuric acid at three concentrations (0.2, 0.6 and 1 M) were assayed. The pretreatments of WH biomass released mono- and oligo-saccharides that favored fungal growth and enzymes production on SSF. WH is a cost-effective substrate-support and inducer, which to be used as a solid medium, was impregnated with a saline solution, containing only (NH4)2SO4, KH2PO4 y MgCl2. Maximum cellulases (carboxymethylcellulase (CMCase)) and xylanases productions of P. crustosum cultured on SSF were reached using the WH pretreated biomass with H2SO4 0.6 M and 121 °C. The simultaneous CMCase and xylanases production reached (647.51 and 4257.35 U/g dry WH, respectively) are among the highest values ever reported.

Sucrose-nonfermenting 1 kinase activates histone acetylase GCN5 to promote cellulase production in Trichoderma.

Trichoderma serves as the primary producer of cellulases and hemicellulases in industrial settings as it readily secretes a variety of cellulolytic enzymes. The protein kinase SNF1 (sucrose-nonfermenting 1) can enable cells to adapt to changes in carbon metabolism by phosphorylating key rate-limiting enzymes involved in the maintenance of energy homeostasis and carbon metabolism within cells. Histone acetylation is an important epigenetic regulatory mechanism that influences physiological and biochemical processes. GCN5 is a representative histone acetylase involved in promoter chromatin remodeling and associated transcriptional activation. Here, the TvSNF1 and TvGCN5 genes were identified in Trichoderma viride Tv-1511, which exhibits promising activity with respect to its ability to produce cellulolytic enzymes for biological transformation. The SNF1-mediated activation of the histone acetyltransferase GCN5 was herein found to promote cellulase production in T. viride Tv-1511 via facilitating changes in histone acetylation. These results demonstrated that cellulolytic enzyme activity and the expression of genes encoding cellulases and transcriptional activators were clearly enhanced in T. viride Tv-1511 mutants in which TvSNF1 and TvGCN5 were overexpressed, with concomitant changes in histone H3 acetylation levels associated with these genes. GCN5 was also found to be directly recruited to promoter regions to alter histone acetylation, while SNF1 functioned upstream as a transcriptional activator that promotes GCN5 upregulation at the mRNA and protein levels in the context of cellulase induction in T. viride Tv-1511. These findings underscore the important role that this SNF1-GCN5 cascade plays in regulating cellulase production in T. viride Tv-1511 by promoting altered histone acetylation, offering a theoretical basis for the optimization of T. viride in the context of industrial cellulolytic enzyme production. KEY POINTS: • SNF1 kinase and GCN5 acetylase promoted cellulase production in Trichoderma by increasing the expression of genes encoding cellulases and transcriptional activators • SNF1 and GCN5 promoted cellulase production by driving H3ac modifications, and GCN5 directly band to the promoter regions to catalyze distinct H3ac modifications • SNF1 acts upstream of GCN5 as a transcriptional activator in the cellulase production of Trichoderma.

Ethanol from cellulose and cellobiose of woody-substrates in a single stage of 3-combined-bioprocesses employing a non-GM yeast cell-factory

The present study aims to prepare a Saccharomyces cerevisiae cell factory, to combine three bioprocesses in a single stage, including cellulolytic enzyme production, cellulose hydrolysis to glucose, and fermentation with low cost of nutrients to ethanol, without any genetic modification. Cell factories are prepared, in which S. cerevisiae cells are covered with starch gel (SG), either containing Trichoderma reesei (SG-T. reesei), or cellulase produced from T. reesei (SG-cellulase). The work comprises the cellulose bioconversion using S. cerevisiae/SG-cellulase, and S. cerevisiae/SG-T. reesei to carry out alcoholic fermentation in one batch with low nutrient cost. In addition, the effect of different concentrations of yeast in the cell factory on fermentation rate was examined. SEM, FTIR spectra analysis and cellulose fermentation were used to prove the successful preparation of cell factory and its activity to ferment cellulose in one combined bioprocess. The cellulose sourced from delignified sawdust was characterized with XRD spectra and porosimetry analysis. Cell factory models of S. cerevisiae/SG-T. reesei and S. cerevisiae/SG-cellulase were able to ferment cellulose from wood, obtaining 32% and 62% ethanol production yield, respectively. S. cerevisiae/SG-T. reesei and S. cerevisiae/SG-cellulase resulted to 4.07 and 7.30 mL ethanol/L, respectively. The final glucose concentration was very low (0–0.07 g glucose/L). It is also concluded that the increase of S. cerevisiae concentration in CF helped an improvement in the bioconversion process.

Biologically derived copper oxide-based nanocatalyst using Moringa oleifera leaves and its applications in hydrolytic enzymes and biohydrogen production

Due to the limited availability of fossil fuels, pollution causing serious environmental issues, and their continuously rising price, the development of low-cost efficient enzymes and their implementation in biomass-based bioenergy industries are highly demanded. In the present work, phytogenic fabrication of copper oxide based nanocatalyst has been performed using moringa leaves and has been characterized using different techniques. Herein, the impact of different dosages of as-prepared nanocatalyst on fungal co-cultured cellulolytic enzyme production under co-substrate fermentation using wheat straw and sugarcane bagasse in 4:2 ratios in solid state fermentation (SSF) has been investigated. An optimal concentration of 25 ppm of nanocatalyst influenced the production of 32 IU/gds of enzyme, which showed thermal stability at 70 °C for 15 h. Additionally, enzymatic bioconversion of rice husk at 70 °C librated 41 g/L of total reducing sugars, which led to the production of 2390 mL/L of cumulative H2 in 120 h.

Production of cellulolytic enzymes from microorganisms isolated from coconut fiber

The worldwide production of microbial enzymes is generally limited by the cost of the substrate used for the cultivation of microorganisms. Thinking of a low-cost and abundant lignocellulosic substrate, coconut fiber is an alternative because it is rich in cellulose, hemicellulose, and lignin, presenting itself as a promising raw material for the production of an enzyme cocktail, which can be used in the production of second-generation biofuels. The objective of this work was to produce cellulolytic enzymes from microorganisms isolated from coconut fiber. In the production of the enzyme, the kinetic profile of the enzymatic complex was evaluated, analyzing the effects of moisture content, temperature, and pH during solid-state fermentation of coconut fiber, using a microorganism isolated from the bagasse itself. Statistica software was used to evaluate the enzyme complex production parameters. Statistical results indicated that the best humidity, temperature, and pH conditions were 80%, 30°C and 3, respectively, with activities of 119.93 U/g CMCase (endoglucanase) and 89.32 U/g FPase (total cellulases ) over a period of 48 h.