Hemicellulase Activities Research Articles

Enzyme-assisted hydrolysis of Theobroma cacao L. pulp

Cocoa pulp, a by-product of the cocoa supply chain, has gained the food sector's attention for its pleasant flavour. Enzyme-assisted technologies to facilitate its separation from the cocoa seeds remain largely unexplored. We studied the effects of temperature, enzyme activity and enzyme combinations on the physicochemical properties of cocoa pulp by Response Surface Methodology and D-optimal design. Endo-polygalacturonase, endo-cellulase and hemicellulase activities were investigated. A reduced quadratic model described the relative reduction in viscosity, of the particle diameter dv,0.9 and of the browning index. Polygalacturonase had the strongest influence on viscosity, while cellulase had the least effect. Synergistic effects of polygalacturonase with cellulase and/or hemicellulase were identified. The model predicted maximal reductions in viscosity by 70.3 % with 275 U of polygalacturonase and 275 U of hemicellulase at 40 °C. Fresh pulp's dv,0.9 was 613 μm. Combining all enzyme activities reduced the dv,0.9–418 μm (40 °C, total activity: 580 U). Only the temperature proved to significantly influence the browning index, with higher temperatures causing a higher colouring effect. Lastly, the model was successfully validated for the relative reduction in viscosity and the dv,0.9. Our study provides key insights into the enzyme-assisted processing of cocoa pulp, facilitating its separation from the seeds. By utilising the pulp, innovative ingredients can be developed for the food sector, and at the same time, the added value in the cocoa supply chain can be improved.

Deciphering the complex interplay between gut microbiota and crop residue breakdown in forager and hive bees (Apis mellifera L.)

This study investigates A. mellifera gut microbiota diversity and enzymatic activities, aiming to utilize identified isolates for practical applications in sustainable crop residue management and soil health enhancement. This study sampled honey bees, analyzed gut bacterial diversity via 16S rRNA gene, and screened isolates for cellulolytic, hemicellulolytic, and pectinolytic activities, with subsequent assessment of enzymatic potential. The study reveals that cellulolytic and hemicellulolytic bacterial isolates, mainly from γ-Proteobacteria, Actinobacteria, and Firmicutes, have significant potential for crop residue management. Some genera, like Aneurinibacillus, Bacillus, Clostridium, Enterobacter, Serratia, Stenotrophomonas, Apilactobacillus, Lysinibacillus, and Pseudomonas, are very good at breaking down cellulose and hemicellulase. Notable cellulose-degrading genera include Cedecea (1.390 ± 0.57), Clostridium (1.360 ± 0.86 U/mg), Enterobacter (1.493 ± 1.10 U/mg), Klebsiella (1.380 ± 2.03 U/mg), and Serratia (1.402 ± 0.31 U/mg), while Aneurinibacillus (1.213 ± 1.12 U/mg), Bacillus (3.119 ± 0.55 U/mg), Enterobacter (1.042 ± 0.14 U/mg), Serratia (1.589 ± 0.05 U/mg), and Xanthomonas (1.156 ± 0.08 U/mg) excel in hemicellulase activity. Specific isolates with high cellulolytic and hemicellulolytic activities are identified, highlighting their potential for crop residue management. The research explores gut bacterial compartmentalization in A. mellifera, emphasising gut physiology's role in cellulose and hemicellulose digestion. Pectinolytic activity is observed, particularly in the Bacillaceae clade (3.229 ± 0.02), contributing to understanding the honey bee gut microbiome. The findings offer insights into microbiome diversity and enzymatic capabilities, with implications for biotechnological applications in sustainable crop residue management. The study concludes by emphasizing the need for ongoing research to uncover underlying mechanisms and ecological factors influencing gut microbiota, impacting honey bee health, colony dynamics, and advancements in crop residue management.

Efficient conversion of tea residue nutrients: Screening and proliferation of edible fungi

Despite lignocellulose hindering the extraction of intracellular components, tea residue can serve as an excellent substrate for fungal fermentation owing to their lignocellulose-degrading abilities. Thus, the fermentation efficiencies of Lentinus edodes, Lentinus sajor-caju (Fr.), Flammulina filiformis, Hericium erinaceus, Pleurotus pulmonarius, and Monascus kaoliang B6 were evaluated using tea residue as a medium. P. pulmonarius and L. sajor-caju (Fr.) exhibited the fastest growth rates, with colony radii of 33.1 and 28.5 mm, respectively. M. kaoliang B6 demonstrated substantial degradation abilities for cellulose, hemicellulose, and lignin, with decolorization radii of 12.2, 0.9, and 8.5 mm, respectively. After a 9-days liquid fermentation, M. kaoliang B6 achieved the highest conversion efficiency at 27.8%, attributed to its high cellulase (191 U∙mL−1) and lignin peroxidase (36.9 U∙L−1) activities. P. pulmonarius and L. sajor-caju (Fr.) showed lower conversion rates of 8.6% and 3.8%, despite having high hemicellulase activities (67.1 and 70.9 U∙mL−1). Fermentation by M. kaoliang B6 resulted in a reduction of protein and total sugar content in the tea residue by 174 and 192 mg g−1, by which the mycelium's protein and total sugar content increased by 73 and 188 mg g−1. Co-fermentation of these three strains had little effect on the improvement of conversion efficiency, which might owe to the antagonistic interactions among the strains. Generally, utilizing tea residue for edible fungi fermentation is a sustainable process for bio-waste treatment, enabling efficient nutrient conversion under mild conditions without adding chemicals.

Multiomics characterisation of the zoo-housed gorilla gut microbiome reveals bacterial community compositions shifts, fungal cellulose-degrading, and archaeal methanogenic activity.

We carried out a comparative analysis between the bacterial microbiota composition of zoo-housed western lowland gorillas and their wild counterparts through 16S rRNA gene amplicon sequencing. In addition, we characterised the carbohydrate-active and methanogenic potential of the zoo-housed gorilla (ZHG) microbiome through shotgun metagenomics and RNA sequencing. The ZHG microbiota showed increased alpha diversity in terms of bacterial species richness and a distinct composition from that of the wild gorilla microbiota, including a loss of abundant fibre-degrading and hydrogenic Chloroflexi. Metagenomic analysis of the CAZyome indicated predominant oligosaccharide-degrading activity, while RNA sequencing revealed diverse cellulase and hemi-cellulase activities in the ZHG gut, contributing to a total of 268 identified carbohydrate-active enzymes. Metatranscriptome analysis revealed a substantial contribution of 38% of the transcripts from anaerobic fungi and archaea to the gorilla microbiome. This activity originates from cellulose-degrading and hydrogenic fungal species belonging to the class Neocallimastigomycetes, as well as from methylotrophic and hydrogenotrophic methanogenic archaea belonging to the classes Thermoplasmata and Methanobacteria, respectively. Our study shows the added value of RNA sequencing in a multiomics approach and highlights the contribution of eukaryotic and archaeal activities to the gut microbiome of gorillas.

Sorbicillinoids hyperproduction without affecting the cellulosic enzyme production in Trichoderma reesei JNTR5

BackgroundMicrobial production of bioactive secondary metabolites is challenging as most of the encoding genes are silent; and even if they are activated, the biosynthetic pathways are usually complex. Sorbicillinoids with multifunctional bioactivities are examples of these problems, which if solved can result in a more sustainable, simple supply of these important compounds to the pharmaceutical industry. As an excellent producer of cellulosic enzymes, Trichoderma reesei can secrete various sorbicillinoids.ResultsHere, we obtained a T. reesei mutant strain JNTR5 from the random mutation during overexpression of gene Tr69957 in T. reesei RUT-C30. JNTR5 exhibited a significant constitutive increase in sorbicillinoids production without affecting the cellulosic enzyme production. Confocal laser scanning microscope (CLSM) results indicated that sorbicillinoids were distributed in both mycelium and spores of JNTR5 with blue and green fluorescence. Compared with RUT-C30, JNTR5 displayed different cell morphology, reduced growth rate, and increased sporulation, but a similar biomass accumulation. Furthermore, transcriptome analysis revealed that all genes belonging to the sorbicillinoid gene cluster were upregulated, while most cellulase-encoding genes were downregulated. The cell wall integrity of JNTR5 was damaged, which might benefit the cellulase secretion and contribute to the almost unchanged cellulase and hemicellulase activity given that the damaged cell wall can enhance the secretion of the enzymes.ConclusionsFor the first time, we constructed a sorbicillinoids hyperproduction T. reesei platform with comparable cellulosic enzymes production. This outperformance of JNTR5, which is strain-specific, is proposed to be attributed to the overexpression of gene Tr69957, causing the chromosome remodeling and subsequently changing the cell morphology, structure, and the global gene expression as shown by phenotype and the transcriptome analysis of JNTR5. Overall, JNTR5 shows great potential for industrial microbial production of sorbicillinoids from cellulose and serves as an excellent model for investigating the distribution and secretion of yellow pigments in T. reesei.

Collaborative Response of the Host and Symbiotic Lignocellulytic System to Non-Lethal Toxic Stress in Coptotermes formosanus Skiraki.

Simple SummaryCoptotermes formosanus Shiraki is a wood feeding lower termite and is widely distributed in many areas. The dynamic adjustment of the C. formosanus digestive system to unfavorable survival environments was investigated via non-lethal toxic feeding. The toxic stress did not change the dominant role of microbial lignocellulases in cellulose degradation of C. formosanus. The core symbiotic community was stable in abundance during the tolerance to the toxic treatment. However, a large number of low abundance taxa were significantly enriched by the low toxic feeding. These rare bacterial lineages likely contribute to toxic stress tolerance of termite. Above all, these findings add important new knowledge to our understanding of environmental adaptation of the lignocellulose hydrolysis system in termites.Disturbing the lignocellulose digestive system of termites is considered to be a promising approach for termite control. The research on the tolerance mechanism of the termite lignocellulose digestive system to harmful environment conditions is limited. In this study, we keep Coptotermes formosanus Skiraki under a non-lethal toxic condition by feeding the termites with filter paper containing the kojic acid (a low toxic insecticide). The effects of low toxic stress on the activities and gene expressions of host/symbiotic originated lignocellulases, and on the symbiotic microbial community structure of C. formosanus were explored. Our result showed that the low toxic stress would lead to the synchronous decrease of cellulase and hemicellulase activities, and supplementary increase of corresponding gene expressions. The symbiotic community maintained its role as the main force in the lignocellulolytic system of C. formosanus. Meanwhile, a large number of rare taxa were significantly enriched by kojic acid treatment. These numerically inconspicuous bacterial populations might be responsible for the functions similar to phenoloxidase or insecticide detoxification and enable C. formosanus to tolerate the harmful environment. Overall, our data suggested that the digestive adaptation of C. formosanus to physiotoxic feeding is closely related to the triple collaboration of termites–flagellates–bacteria.

The antifungal mechanism of konjac flying powder extract and its active compounds against wood decay fungi

Wood products are vulnerable to fungal degradation that reduces service life. Traditional wood preservatives can provide excellent service life but efforts are underway to develop more natural methods for wood protection. Konjac flying powder is a residual waste produced during the processing of corms of Konjac (Amorphophallus konjac K. Koch) to produce Konjac flour. This waste material contains a number of compounds including salicylic acid (SA), 2,4,6-trichlorophenol (TCP), vanillin (VL), and cinnamaldehyde (CMA) has been found to be active against decay fungi; however, the antifungal mode of action is uncertain. The effects of konjac flying powder extract (KFPE) and its active compounds on cellulase, hemicellulose and ligninase activity, respiratory metabolism, cell membrane permeability, protein, and energy metabolism was studied on the white-rot fungus, Trametes versicolor (L. ex Fr.) Quél. (T. versicolor) and brown-rot fungus, Gloeophyllum trabeum (Pers.: Fr.) Murr. (G. trabeum). Konjac flying powder inhibited cellulase and hemicellulase activity of both fungi and ligninase activity of T. versicolor. Respiratory metabolism and energy metabolism were also inhibited. The four active compounds had different effects on activities suggesting that konjac flying powder functioned against multiple metabolic activities of the test fungi, potentially increasing its ability to provide broad spectrum wood protection.

The study of the main impurities mature mash depending on the duration of fermentation, yeast alcohol race and used enzyme preparations

The paper studied the process of intensification of concentrated fermentation mash with account of the complex amylolytic enzymes, hemicellulase and proteolytic activities. We determined the dependence of ethanol yield, the content of volatile impurities, the content of reducing substances, depending on the different strains of yeast at a seed rate 15 million cells per 1 cm3 wort. To identify the parameters of the fermentation process the wort with an increased solids content, investigated the dynamics of accumulation of volatile impurities by varying the rate and duration of seeding yeast fermentation using 987-O5 race yeast. It revealed that the qualitative composition of impurities in the mash, the resulting wort of high-concentration depends both on the duration of fermentation, and from normal seeding yeast. Thus, depending on the duration of the fermentation process, the acetaldehyde content increases (from 613,17 mg/dm? to 54 h to 1724,6 mg/dm? to 72 hours), the amount of ethyl acetate is reduced (from 409,2 mg/dm? to 54 hours prior to 207 mg/dm? to 72 hours), the methanol content to 54 h at a rate of 15 million yeast seeding cells per 1 cm? of the wort amounted to 0,0043 mg/cm?, whereas by 72 h of fermentation at the same seed rate yeast – 0,0070 mg/dm?, the amount of 1-propanol and 1-butanol was reduced from 903,14 mg/cm? and 6,38 mg/cm? -54 h to 880 mg/cm? and 5,57 mg/cm? - to 72 hours, respectively. The minimum content of isobutanol independent of the duration of fermentation was 900-1100 mg/cm? at a seed rate 15 million yeast cells per 1 cm? wort izoamilola number increases from 1219,08 mg/dm? (54 hr) to 2673,84 mg/dm? (72 h). It revealed that the smallest total amount of impurities obtained by seed rate yeast 15 million cells per 1 cm? wort at the duration of fermentation 54 hours was found that maximum ethanol content in the mash with minimal accumulation therein volatiles corresponds embodiment:. Duration of fermentation - 54 hours at normally the problem of yeast cells – 15,0 million / cm? wort.

Improving β-glucosidase and xylanase production in a combination of waste substrate from domestic wastewater treatment system and agriculture residues

Cellulase and hemicellulase activities are considered to the major bottlenecks in the lignocellulosic biorefinery process, especially in an enzyme cocktail lacking β-glucosidase (BGL) and xylanase (XYL). In view of this issue, higher levels of BGL and XYL activities were obtained in the presence of wastewater and activated sludge as an induction medium mixed with 5% of rice straw by Hypocrea sp. W63. The analysis of the ionic content showed that a relatively low sludge dose could enhance the production of BGL and XYL. Most importantly, compared to a medium using freshwater, the proportion of 1:10 sludge to wastewater, which contained nutrient elements, led to 3.4-fold BGL and 3.7-fold XYL production improvements. This research describes the reuse of substrates that are largely and continuously generated from domestic wastewater treatment systems and agriculture residues, which consequently leads to the development of a simultaneous enzyme production process for sustainable biorefinery practices.

Enhancing the hydrolysis process in a dry anaerobic digestion process for the organic fraction of municipal solid waste

The potential of leachate recirculation and enzyme addition for increasing the conversion efficiency of a 2-stage dry anaerobic digestion process of OFMSW was studied and compared to a 1-stage setup. In the 2-stage reactor setup the methane yield increased from 31 to 227 ml-CH4/g-VS by lowering waste/percolate ratio from 6.5 to 2 (based on VS). Eventual pH increase and lower VFA release in the leachate indicated that methanogenesis occurred also in the first stage of the 2-stage system. The high waste/percolate ratio of 6.5 lead to overload of both 1- and 2-stage processes while lowering the waste/percolate ratio to 4 resulted in a methane yield of 268 ml-CH4/g-VS in the 1-stage reactor system. The higher water saturation of the waste led obviously to more homogenous process conditions. Addition of two different enzyme blends with cellulase and hemicellulase activity resulted in 19% increase of the methane potential.

The functioning of a novel protein, Swollenin, in promoting the lignocellulose degradation capacity of Trichoderma guizhouense NJAU4742 from a proteomic perspective

The functioning of a novel auxiliary enzyme, TgSWO from Trichoderma guizhouense NJAU4742, was investigated based on the proteomic analysis of wild-type (WT), knockout (KO) and overexpression (OE) treatments. The results showed that the cellulase and hemicellulase activities of OE and WT were significantly higher than those of KO. Simultaneously, tandem mass tag (TMT) analysis results indicated that cellulases and hemicellulases were significantly upregulated in OE, especially hydrophobin (HFB, A1A105805.1) and endo-β-1,4-glucanases (A1A101831.1), with ratios of 43.73 and 9.88, respectively, compared with WT. The synergistic effect of TgSWO on cellulases increased the reducing sugar content by 1.45 times in KO + TgSWO (1.8 mg) compared with KO, and there was no significant difference between KO + TgSWO (1.2 mg) and WT. This study elucidated the function of TgSWO in promoting the lignocellulose degradation capacity of NAJU4742, which provides new insights into the efficient conversion of lignocellulose.

The effect of commercial pectolytic enzymes on young Babić wines quality

The purpose of this research was to determine the effect of commercial pectolytic enzymes on the anthocyanin composition, colour parameters and specific sensory atributes in young wines produced of Croatian autochthonous variety Babić. The maceration without commercial enzymes was compared with two different enzymes: pectinase with additional cellulase and hemicellulase activity (A) and the pectinase with inactive yeast cells (B), during two harvests. Both products had a positive effect on the anthocyanin content and composition, but with different intensities. The influence of enzymes was confirmed through the colour parameters; intensity, hue and the ratio between yellow, red and blue, depending on product. Young wines produced with pectinase enzyme were significantly better, for all parameters. The sensory analysis showed that wines produced with pectinase enzyme (product A) were significantly better than those produced without enzymes. The combination of pectolytic enzymes and inactive yeast cells (product B) had a partial positive effect on the anthocyanins, colour parameters and sensory quality during two harvests. The use of specific commercial pectolytic enzymes can be a good and beneficial technological treatment in production of Babić young wine, based on preliminary research. These data confirmed the need to carry out research prior to use in real production, to select and recommend certain commercial enzyme products, according to the particular grape variety and certain wine properties that want to be improved.

Rational engineering of the Trichoderma reesei RUT-C30 strain into an industrially relevant platform for cellulase production

BackgroundThe path for the development of hypersecreting strains of Trichoderma reesei capable of producing industrially relevant enzyme titers remains elusive despite over 70 years of research and industrial utilization. Herein, we describe the rational engineering of the publicly available T. reesei RUT-C30 strain and a customized process for cellulase production based on agroindustrial by-products.ResultsA CRISPR/Cas9 system was used to introduce six genetic modifications in RUT-C30. Implemented changes included the constitutive expression of a mutated allele of the cellulase master regulator XYR1, the expression of two heterologous enzymes, the β-glucosidase CEL3A from Talaromyces emersonii and the invertase SUC1 from Aspergillus niger, and the deletion of genes encoding the cellulase repressor ACE1 and the extracellular proteases SLP1 and PEP1. These alterations resulted in a remarkable increase of protein secretion rates by RUT-C30 and amended its well described β-glucosidase deficiency while enabling the utilization of sucrose and eliminating the requirement of inducing sugars for enzyme production. With a developed sugarcane molasses-based bioprocess, the engineered strain reached an extracellular protein titer of 80.6 g L−1 (0.24 g L−1 h−1), which is the highest experimentally supported titer so far reported for T. reesei. The produced enzyme cocktail displayed increased levels of cellulase and hemicellulase activities, with particularly large increments being observed for the specific activities of β-glucosidase (72-fold) and xylanase (42-fold). Notably, it also exhibited a saccharification efficiency similar to that of a commercially available cellulase preparation in the deconstruction of industrially pretreated sugarcane straw.ConclusionThis work demonstrates the rational steps for the development of a cellulase hyperproducing strain from a well-characterized genetic background available in the public domain, the RUT-C30, associated with an industrially relevant bioprocess, paving new perspectives for Trichoderma research on cellulase production.

Optimization by response surface methodology of the enzymatic hydrolysis of non-pretreated agave bagasse with binary mixtures of commercial enzymatic preparations

Optimum conditions for the enzymatic hydrolysis of non-pretreated agave bagasse using two binary mixtures of commercial enzymatic preparations with cellulase and hemicellulase activities (Celluclast 1.5 L/Viscozyme L and Cellic® Ctec2/Cellic® Htec2) were determined. The optimization was carried out by using the response surface methodology (RSM). Two response variables were analyzed, hydrolysate reducing sugar concentration (RS; mg/mL) and saccharification yield (SY; mg RS/g bagasse). Higher RS concentration (27.58 ± 3.68 mg/mL) and SY (312.54 ± 46.89 mg RS/g bagasse) were obtained with the mixture Celluclast 1.5 L and Viscozyme L, even when compared with lignocellulosic biomass specialized enzyme mixture of Cellic® Ctec2 and Cellic® Htec2. The RS concentration in the hydrolysate and the SY obtained under optimal conditions for both enzymatic mixtures were higher when compared with previous results. In the case of the mixture Cellic® Ctec2 and Cellic® Htec2, an increase of 5.4- and 2.2-times for the RS concentration and SY were respectively observed, while in the case of the mixture Celluclast 1.5 L and Viscozyme L, an increase of 2- and 1.6-times were detected. The degree of synergy (DS) for the enzymatic hydrolysis was 1.52 (with SY as response variable) and 1.65 (with RS concentration as response variable) for the mixture of Celluclast 1.5 L and Viscozyme L, which indicates the synergism between the enzymes present in this binary mixture.

ENZYMATIC MODIFICATION OF WHEAT RICE

The article presents conceptual approaches to solving technological and technical problems in the creation of functional foods. General approaches are proposed to change existing technologies to improve the efficiency of integrated raw material processing and to increase the production of high-quality foods and food ingredients with antioxidant properties. Cereal crops are the richest source of functional ingredients and a major component of human nutrition. It is proved that most of the nutrients are in the products of its processing. For the first time, polyphenols from cereal raw materials were obtained by biotechnological means. The feasibility of pretreatment of raw materials with amylolytic and proteolytic enzymes for purification and cleavage of polysaccharide matrix has been established. Based on the regularities of enzymatic hydrolysis of polysaccharides, we used the processing of wheat bran with multifunctional drug Viscozyme L with hemicellulase, cellulase, pectinesterase and feruloesterase activities, which resulted in a high effect of degradation of certain covalent cells, ferulic acid from 40.99 to 2507.9 mcg / g. It is determined that this method of obtaining the target components allows to preserve their native structure, especially the supramolecular structure, which determines their physiological effect. The influence of plant polyphenols on the cultivation of probiotic microorganisms is characterized. the comparative characterization of the prebiotic properties of the polyphenols obtained from wheat bran and the concentrate of the polyphenols from the grape buds "ENOANT" are substantiated. The possibility of increasing the proportion of free polyphenols by fermentation of wheat bran is shown. It is established that the extract of polyphenols from wheat bran can be used for its purpose as an effective antioxidant, which does not have a negative effect on the state of the basic physiological systems of the body.

Flax treatment with strategic enzyme combinations: Effect on fiber fineness and mechanical properties of composites

The application of natural fibers as reinforcement material in composites can make an important contribution toward a more sustainable bio-based economy. To use these natural fibers, they need to be released from the stem. Traditionally, this is realized by dew retting. However, there are some disadvantages to this retting procedure. Due to changing weather conditions, it is quite difficult to guarantee a good and consistent fiber quality. Replacing the traditional retting process by a biocatalytic process may resolve these issues through application of a combination of pectinase and hemicellulase activities. In this context, several strategic pectinase and hemicellulase activities were blended. Flax fiber fineness and mechanical properties of resulting unidirectional fiber–epoxy composites were studied after treatment of flax stems with these strategic enzyme combinations. Characterization of fiber fineness showed a higher percentage of fiber widths smaller than 100 µm after combined treatment with two enzymes (44.7%), and the percentage was even higher after some combinations with three enzymes (51.2%). Assessment of mechanical properties of composites showed no significant differences in tensile or transverse properties for combined enzymatic treatments. Fiber properties were back-calculated from unidirectional flax fiber–epoxy composites and a Young’s modulus of 88 GPa and a tensile strength of 865 MPa were observed. Enzymatic extraction resulted in the achievement of similar results as dew retting concerning mechanical composite performance and fiber fineness.

Bioethanol production from rice straw through an enzymatic route mediated by enzymes developed in-house from Aspergillus fumigatus

This study concerns the in-house development of enzymes from Aspergillus fumigatus and their application in separate hydrolysis and fermentation (SHF) processes for bioethanol production from pretreated rice straw. The cellulase and hemicellulase activities of A. fumigatus cultivated in NaOH-pretreated rice straw were much higher than those of A. fumigatus cultivated in raw rice straw. A. fumigatus cultivated in raw rice straw exhibited no lignin-degrading manganese peroxidase (MnP) or laccase enzymatic activity. However, A. fumigatus cultivated in NaOH-pretreated rice straw exhibited high lignin-degrading MnP and laccase enzymatic activity. A. fumigatus completely degraded 1.0% NaOH-pretreated rice straw, yielding 27.89 g/L reducing sugar upon loading of 50 g/L rice straw (based on the original amount of rice straw that went to pretreatment). Saccharification of 1.0% NaOH-pretreated rice straw using 200 FPU/mL crude enzyme released 22.15 g/L reducing sugars in 20 h. The SHF processes resulted in an ethanol concentration and yield of 9.45 g/L and 83.5%, respectively, with Saccharomyces tanninophilus.

Novel process to obtain aguamiel by directed fermentation

The functioning of a novel auxiliary enzyme, TgSWO from Trichoderma guizhouense NJAU4742, was investigated based on the proteomic analysis of wild-type (WT), knockout (KO) and overexpression (OE) treatments. The results showed that the cellulase and hemicellulase activities of OE and WT were significantly higher than those of KO. Simultaneously, tandem mass tag (TMT) analysis results indicated that cellulases and hemicellulases were significantly upregulated in OE, especially hydrophobin (HFB, A1A105805.1) and endo-β-1,4-glucanases (A1A101831.1), with ratios of 43.73 and 9.88, respectively, compared with WT. The synergistic effect of TgSWO on cellulases increased the reducing sugar content by 1.45 times in KO + TgSWO (1.8 mg) compared with KO, and there was no significant difference between KO + TgSWO (1.2 mg) and WT. This study elucidated the function of TgSWO in promoting the lignocellulose degradation capacity of NAJU4742, which provides new insights into the efficient conversion of lignocellulose.

Significant enzymatic activities in the residues hydrolysis of the sugar cane harvest

In the production of ethanol from agroindustrial crop residues, one of the critical stages in the process is the conversion of lignocellulosic material to simple sugars, which can be done chemically or enzymatically. In this research, the enzymatic activities of commercial enzymes were evaluated for their influence on the degradation of lignocellulosic materials from sugar cane harvest residues (leaves and top cane). Eight substrates were pretreated with different delignification methods. Likewise, five enzymatic preparations were configured. An analysis of the enzyme-substrate interactions was conducted through fuzzy system analysis. The results showed regions of maximum enzymatic activity for residues of the sugarcane harvest, between 20-30 Filter Paper Units (FPU) /mL values lower than 500 pNPG (p-Nitrofenol-α-D-Glucopyranoside) U / mL of activity beta-glucosidase and hemicellulase activity between 50 and 70 IU / mL, confirming that the use of large amounts of cellulolytic enzymes is not necessary.

Design and construction of synthetic cellulosome with three adaptor scaffoldins for cellulosic ethanol production from steam-exploded corn stover

In this study, a cellulosome-producing yeast reaction system with cellulase and hemicellulase activities is developed for synergistic catalysis of steam-exploded corn stover. Three adaptor scaffoldins with divergent specificities serve to contain an extensive type and amount of catalytic subunits. The maximum ethanol concentration of engineered yeast strain was 0.92 g/l corresponding to 53.44% of the theoretical yield based on grams of ethanol produced per gram of consumed total sugar under 30 °C with agitation at 90 rpm after 96 h. Here, our elaborated structural organization presents an approach designed toward genetic engineering of S. cerevisiae, a widespread, industrially important microorganism, for improved lignocellulolytic potential and advanced capability of consolidated bioprocessing.