Reesei Strain Research Articles

Safety evaluation of the food enzyme lysophospholipase from the genetically modified Trichoderma reesei strain DP-Nyc81.

The food enzyme lysophospholipase (2-lysophosphatidylcholine acylhydrolase, EC 3.1.1.5) is produced with the genetically modified Trichoderma reesei strain DP-Nyc81 by Genencor International B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the processing of cereals and other grains for the production of glucose syrups and other starch hydrolysates. Since residual amounts of food enzyme-total organic solids are removed during these food manufacturing processes, dietary exposure was not calculated and toxicological studies were considered unnecessary. A search for the identity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

The protein methyltransferase TrSAM inhibits cellulase gene expression by interacting with the negative regulator ACE1 in Trichoderma reesei

Protein methylation is a commonly posttranslational modification of transcriptional regulators to fine-tune protein function, however, whether this regulation strategy participates in the regulation of lignocellulase synthesis and secretion in Trichoderma reesei remains unexplored. Here, a putative protein methyltransferase (TrSAM) is screened from a T. reesei mutant with the ability to express heterologous β-glucosidase efficiently even under glucose repression. The deletion of its encoding gene trsam causes a significant increase of cellulase activities in all tested T. reesei strains, including transformants of expressing heterologous genes using cbh1 promotor. Further investigation confirms that TrSAM interacts with the cellulase negative regulator ACE1 via its amino acid residue Arg383, which causes a decrease in the ACE1-DNA binding affinity. The enzyme activity of a T. reesei strain harboring ACE1R383Q increases by 85.8%, whereas that of the strains with trsam or ace1 deletion increases by more than 100%. By contrast, the strain with ACE1R383K shows no difference to the parent strain. Taken together, our results demonstrate that TrSAM plays an important role in regulating the expression of cellulase and heterologous proteins initiated by cbh1 promotor through interacting with ACE1R383. Elimination and mutation of TrSAM and its downstream ACE1 alleviate the carbon catabolite repression (CCR) in expressing cellulase and heterologous protein in varying degrees. This provides a new solution for the exquisite modification of T. reesei chassis.

Safety evaluation of an extension of use of the food enzyme containing cellulase, endo-1,3(4)-β-glucanase and endo-1,4-β-xylanase from the non-genetically modified Trichoderma reesei strain AR-256.

The food enzyme containing cellulase (EC 3.2.1.4), endo-1,3(4)-β-glucanase (EC 3.2.1.6) and endo-1,4-β-xylanase (EC 3.2.1.8) is produced with the non-genetically modified Trichoderma reesei strain AR-256 by AB-Enzymes GmbH. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in seven food manufacturing processes. Subsequently, the applicant requested to extend its use to include two additional processes. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of nine food manufacturing processes: processing of cereals and other grains for the production of 1) baked products, 2) cereal-based products other than baked, 3) brewed products, 4) starch and gluten fractions, 5) distilled alcohol; processing of fruits and vegetables for the production of 6) wine and wine vinegar, 7) juices, 8) fruit and vegetable products other than juices and 9) fruit-derived distilled alcoholic beverages other than from grape. As the food enzyme-total organic solids (TOS) is removed from or not carried into the final foods in three food manufacturing processes, the dietary exposure to the food enzyme-TOS was estimated only for the remaining six processes. It was up to 4.049 mg TOS/kg body weight (bw) per day in European populations. Using the no observed adverse effect level (NOAEL) reported in the previous opinion (939 mg TOS/kg bw per day), the Panel derived a revised margin of exposure of at least 232. Based on the revised exposure calculation and the outcome of the previous evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Safety evaluation of the food enzyme endo-polygalacturonase from the genetically modified Trichoderma reesei strain RF6197.

The food enzyme endo-polygalacturonase ((1-4)-α-d-galacturonan glycanohydrolase; EC 3.2.1.15) is produced with the genetically modified Trichoderma reesei strain RF6197 by AB Enzymes GmbH. The genetic modifications do not give rise to safety concerns. The food enzyme was considered free from viable cells of the production organism and its DNA. It is intended to be used in five food manufacturing processes: fruit and vegetable processing for juice production, fruit and vegetable processing for products other than juices, production of wine and wine vinegar, coffee demucilation and production of plant extracts as flavouring preparations. Since residual amounts of the total organic solids (TOS) are removed during the coffee demucilation and the production of flavouring extracts, dietary exposure was calculated only for the remaining three food processes. It was estimated to be up to 0.156 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,000 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 6,410. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and matches were found with a number of pollen allergens. The Panel considered that, under the intended conditions of use, the risk of allergic reactions by dietary exposure, particularly in individuals sensitised to pollen cannot be excluded. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme pectinesterase from the genetically modified Trichoderma reesei strain RF6201.

The food enzyme pectinesterase (pectin pectylhydrolase; EC 3.1.1.11) is produced with the genetically modified Trichoderma reesei strain RF6201 by AB Enzymes GmbH. The genetic modifications do not give rise to safety concerns. The food enzyme was considered free from viable cells of the production organism and its DNA. It is intended to be used in five food manufacturing processes: fruit and vegetable processing for juice production, fruit and vegetable processing for products other than juices, production of wine and wine vinegar, coffee demucilation and production of plant extracts as flavouring preparations. Since residual amounts of the total organic solids (TOS) are removed during the coffee demucilation and the production of flavouring extracts, dietary exposure was calculated only for the remaining three food processes. It was estimated to be up to 0.532 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,000 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 1,880. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and two matches were found with pollen allergens. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure, particularly in individuals sensitised to pollen allergens, cannot be excluded. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

BsEXLX of engineered Trichoderma reesei strain as dual-active expansin to boost cellulases secretion for synergistic enhancement of biomass enzymatic saccharification in corn and Miscanthus straws

In this study, bacterial BsEXLE1 gene was overexpressed into T. reesei (Rut-C30) to generate a desirable engineered TrEXLX10 strain. While incubated with alkali-pretreated Miscanthus straw as carbon source, the TrEXLX10 secreted the β-glucosidases, cellobiohydrolases and xylanses with activities raised by 34%, 82% and 159% compared to the Rut-C30. Supplying EXLX10-secreted crude enzymes and commercial mixed-cellulases for two-step lignocellulose hydrolyses of corn and Miscanthus straws after mild alkali pretreatments, this work measured consistently higher hexoses yields released by the EXLX10-secreted enzymes for synergistic enhancements of biomass saccharification in all parallel experiments examined. Meanwhile, this study detected that the expansin, purified from EXLX10-secreted solution, was of exceptionally high binding activities with wall polymers, and further determined its independent enhancement for cellulose hydrolysis. Therefore, this study raised a mechanism model to highlight EXLX/expansin dual-activation roles for both secretion of stable biomass-degradation enzymes at high activity and biomass enzymatic saccharification in bioenergy crops.

Metabolic Engineering of Trichoderma reesei for l-Malic Acid Production.

l-Malic acid has various applications in the chemical and food industries. The filamentous fungus Trichoderma reesei is known to be an efficient enzyme producer. Here, through metabolic engineering, T. reesei was constructed for the first time as an excellent cell factory for l-malic acid production. The heterologous overexpression of genes encoding the C4-dicarboxylate transporter from Aspergillus oryzae and Schizosaccharomyces pombe initiated l-malic acid production. The overexpression of pyruvate carboxylase from A. oryzae in the reductive tricarboxylic acid pathway further increased both the titer and yield of l-malic acid, resulting in the highest titer reported in a shake-flask culture. Furthermore, the deletion of malate thiokinase blocked l-malic acid degradation. Finally, the engineered T. reesei strain produced 220.5 g/L of l-malic acid in a 5 L fed-batch culture (productivity of 1.15 g/L/h). A T. reesei cell factory was created for the efficient production of l-malic acid.

Safety evaluation of the food enzyme pectin lyase from the genetically modified Trichoderma reesei strain RF6199.

The food enzyme pectin lyase ((1-4)-6-O-methyl-α-D-galacturonan lyase; EC 4.2.2.10) is produced with the genetically modified Trichoderma reesei strain RF6199 by AB Enzymes GmbH. The genetic modifications do not give rise to safety concerns. The food enzyme is considered free from viable cells of the production organism and its DNA. It is intended to be used in six manufacturing processes: fruit and vegetable processing for juice production, fruit and vegetable processing for fruit brandies, fruit and vegetable processing for products other than juices, wine and wine vinegar production, refined and unrefined sugar production and coffee bean demucilation. Foods obtained from fruit processing for fruit brandies and coffee bean demucilation, as well as refined sugars, were excluded from dietary exposure estimation. For the remaining four processes, dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.2mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panelidentified a no observed adverse effect level of 1,000mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, results in a margin of exposure of at least 5,000. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panelconsidered that, under the intended conditions of use, the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood of such reactions is low. Based on the data provided, the Panelconcluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of the food enzyme containing cellulase, endo‐1,3(4)‐β‐glucanase and endo‐1,4‐β‐xylanase activities from the non‐genetically modified Trichoderma reesei strain AR‐256

The food enzyme containing cellulase (EC 3.2.1.4), endo-1,3(4)-β-glucanase (EC 3.2.1.6) and endo-1,4-β-xylanase (EC 3.2.1.8) is produced with the non-genetically modified Trichoderma reesei strain AR-256 by AB-Enzymes GmbH. The food enzyme is considered free from viable cells of the production organism. It is intended to be used in seven food manufacturing processes: baking processes, cereal-based processes, brewing processes, fruit and vegetable processing for juice production, wine and wine vinegar production, distilled alcohol production and grain treatment for production of starch and gluten fractions. Since the residual amounts of total organic solids (TOS) are removed during grain treatment and distilled alcohol production, dietary exposure was estimated for the remaining five processes and amounted up to 3.92mg TOS/kg body weight (bw) per day. The toxicity studies were carried out with an endo-1,4-β-xylanase from T. reesei ■■■■■, considered by the Panelas a suitable substitute, because the genetic differences between the strains are well characterised and of no concern. Additionally, several strains derived from the production strain are considered safe by EFSA and the manufacturing of both food enzymes is similar. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by a repeated dose 90-day oral toxicity rat study. The no observed adverse effect level of 939mg TOS/kg bw per day, the highest dose tested, compared with the estimated dietary exposure, resulted in a margin of exposure above 239. In the search for thesimilarity of the amino acid sequences to known allergens, one match (salmon) was found. The Panelconsidered that, under the intended conditions of use (except distilled alcohol production), the risk of allergic reactions by dietary exposure cannot be excluded, in particular for individuals sensitised to salmon. The Panelconcluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Development of an economically competitive Trichoderma-based platform for enzyme production: Bioprocess optimization, pilot plant scale-up, techno-economic analysis and life cycle assessment

Despite decades of research and industrial applications of Trichoderma reesei, the development of industrially relevant strains for enzyme production including a low-cost and scalable bioprocess remains elusive. Herein, bioprocess optimization, pilot plant scale-up, techno-economic analysis and life-cycle assessment for enzyme production by an engineered T. reesei strain are reported. The developed bioprocess increased in ∼ 2-fold protein productivity (0.39 g.L-1.h−1) and 1.6-fold FPase activity (196 FPU.L-1.h−1), reducing the fermentation in 4 days. Cultivation in a 65-L pilot plant bioreactor resulted in 54 g.L-1 protein in 7 days, highlighting the robustness and scalability of this bioprocess. Techno-economic analysis indicates an enzyme cost of ∼ 3.2 USD.kg−1, which is below to the target proposed (4.24 USD.kg−1) in the NREL/TP-5100–47764 report, while life-cycle assessment shows a carbon footprint reduction of approximately 50% compared to a typical commercial enzyme. This study provides the fundamental knowledge for the design of economically competitive Trichoderma technologies for industrial use.

Safety evaluation of the food enzyme mannan endo-1,4-β-mannosidase from the genetically modified Trichoderma reesei strain RF6232.

The food enzyme mannan endo‐1,4‐β‐mannosidase (1,4‐β‐d‐mannan mannanohydrolase; EC 3.2.1.78) is produced with the genetically modified Trichoderma reesei strain RF6232 by AB Enzymes GmbH. The genetic modifications do not give rise to safety concerns. The food enzyme was considered free from viable cells of the production organism and recombinant DNA. It is intended to be used in coffee processing, fruit and vegetable processing for juice production and for edible oil production. Since residual amounts of total organic solids (TOS) are removed during refined edible oil production by repeated washing, dietary exposure was calculated only for the remaining two food manufacturing processes. Dietary exposure to the food enzyme–TOS was estimated to be up to 0.09 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 100 mg TOS/kg bw per day, the lowest dose tested. This results in a margin of exposure above 1,100. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and one match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, in particular for individuals allergic to avocado, but the likelihood for this to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme cellulase from the genetically modified Trichoderma reesei strain AR-852.

The food enzyme cellulase (4‐(1,3;1,4)‐β‐d‐glucan 4‐glucanohydrolase; EC 3.2.1.4) is produced with the genetically modified Trichoderma reesei strain AR‐852 by AB Enzymes GmbH. The genetic modifications did not give rise to safety concerns. The food enzyme is considered free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in five food manufacturing processes: baking processes, brewing processes, distilled alcohol production, wine and wine vinegar production, and fruit and vegetable processing for juice production. As residual amounts of total organic solids (TOS) are removed by distillation, dietary exposure was only calculated for the other four food processes. Dietary exposure to the food enzyme TOS was estimated to be up to 0.1 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,000 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure of at least 10,000. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use (other than distilled alcohol production) the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme glucose oxidase from the genetically modified Trichoderma reesei strain AR-352.

The food enzyme glucose oxidase (β‐d‐glucose:oxygen 1‐oxidoreductase; EC 1.1.3.4) is produced with the genetically modified Trichoderma reesei strain AR‐352 by AB Enzymes GmbH. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism, but the absence of its recombinant DNA could not be established. The food enzyme is intended to be used in four food manufacturing processes, namely baking processes, cereal‐based processes, grain treatment for the production of starch and gluten fractions, and egg processing. Since residual amounts of total organic solids (TOS) are removed by repeated washing during the production of starch and gluten, dietary exposure was calculated only for the remaining three processes. Dietary exposure to the food enzyme–TOS was estimated to be up to 0.13 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,000 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure of more than 7,800. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and one match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of the food enzyme endo-1,4-β-xylanase from the genetically modified Trichoderma reesei strain NZYM-ER.

The food enzyme endo‐1,4‐β‐xylanase (4‐β‐d‐xylan xylanohydrolase; EC 3.2.1.8) is produced with the genetically modified Trichoderma reesei strain NZYM‐ER by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is considered free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in brewing processes, distilled alcohol production, grain treatment for the production of starch and gluten fractions and for palm oil production. Since residual amounts of total organic solids (TOS) are removed by distillation, in palm oil production and in grain treatment for the production of starch and gluten fraction, dietary exposure was only calculated for brewing processes. Dietary exposure to the food enzyme TOS was estimated to be up to 0.09 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,051 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure of at least 11,400. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use (other than distilled alcohol production) the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme non-reducing end α-l-arabinofuranosidase from the genetically modified Trichoderma reesei strain NZYM-GV.

The food enzyme non‐reducing end α‐l‐arabinofuranosidase (α‐l‐arabinofuranoside non‐reducing end α‐l‐arabinofuranosidase; EC 3.2.1.55) is produced with the genetically modified Trichoderma reesei strain NZYM‐GV by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in grain treatment for the production of starch and gluten fractions. Since residual amounts of total organic solids (TOS) are removed by washing and purification steps applied during grain treatment, the estimation of a dietary exposure is considered not necessary. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,116 mg TOS/kg body weight per day, the highest dose tested. Similarity of the amino acid sequence to those of known allergens was searched and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided and the removal of TOS during the grain treatment, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Reformulating the Hydrolytic Enzyme Cocktail of Trichoderma reesei by Combining XYR1 Overexpression and Elimination of Four Major Cellulases to Improve Saccharification of Corn Fiber.

The industrial fungus Trichoderma reesei has an outstanding capability of secreting an enzyme cocktail comprising multiple plant biomass-degrading enzymes. Herein, the overexpression of XYR1, the master transactivator controlling (hemi)cellulase gene expression, was performed in T. reesei lacking four main cellulase-encoding genes. The resultant strain Δ4celOExyr1 was able to produce a dramatically different profile of secretory proteins on soluble glucose or lactose compared with that of the wild-type T. reesei. The Δ4celOExyr1 secretome included cellulases EGIII and BGLI as well as several hemicellulases and nonhydrolytic cellulose degradation-associated proteins that are not preferentially induced in the wild-type T. reesei strain. Δ4celOExyr1 produced a significant amount of α-arabinofuranosidase I on lactose, and the crude enzyme cocktail of Δ4celOExyr1 not only released a considerable quantity of glucose but also exhibited remarkable performance in the hydrolytic release of xylose, arabinose, and mannose from un-pretreated corn fiber. These results showed that the engineered T. reesei strain holds great potential for improving the saccharification efficiency of the hemicellulosic constituents within corn fiber.

Production of D-galacturonic acid from pomelo peel using the crude enzyme from recombinant Trichoderma reesei expressing a heterologous exopolygalacturonase gene

D-galacturonic acid is a starting material for synthesizing biochemicals used in cosmetic, pharmaceutical, and fuel industries. Utilization of one-step enzymatic hydrolysis method for D-galacturonic acid production can reduce the use of toxic chemical and avoid high temperature in pectin extraction process. However, lack of efficient enzymes facilitating degradation of pectin-rich biomass into D-galacturonic acid limited an implementation of this process. In this study, a heterologous exoPG gene encoding exopolygalacturonase (exoPG), a key pectinase enzyme originating from Aspergillus aculeatus, was expressed in a well-known industrial cellulase-producing strain, Trichoderma reesei RUT-C30. Application of this crude enzyme in the pectin-rich pomelo peel hydrolysis at 60 °C, pH 6.0 for 48 h resulted in up to 151.1 mg/g D-galacturonic acid, which was approximately 6.1-fold higher than that obtained by the enzyme prepared from the parental strain. Further economic assessment of D-galacturonic acid production by using crude enzyme from the recombinant T. reesei revealed that the investment could be returned within 0.5–0.7 year, suggesting profitability of the developed process. The crude enzyme from the engineered T. reesei strain developed in this study promises a clean and sustainable production of D-galacturonic acid from low-cost agricultural waste.

Cytotoxic and Antimicrobial Activities of Ethyl Acetate Extract from Fungus Trichoderma reesei strain JCM 2267, Aspergillus flavus strain MC- 10-L, Penicillium sp, and Aspergillus fumigatus Associated with Marine Sponge Stylissa flabelliformis

This study was to investigate the cytotoxic and antimicrobial activities of ethyl acetate extract yielded from fermented fungi Trichoderma reesei strain: JCM 2267, Aspergillus flavus strain MC-10-L, Penicillium sp, and Aspergillus fumigatus associated with Stylissa flabelliformis sponge, and also to investigate the significant component in ethyl acetate extract of it. Antimicrobial experimentation was performed to various microbes with liquid microdilution method. The assessment of antimicrobials was undertaken by observing the value of MIC50. Cytotoxic testing was performed using MTT assay method. The cytotoxic activity evaluation was conducted by finding the value of IC50. The compound analysis in the ethyl acetate extract was used GC-MS. The result showed that in the antimicrobial experimentation, there was a variation in the percentage of inhibition where the smallest MIC50 values were found in Aspergillus fumigatus fungi ethyl acetate extract against Candida albicans ATCC 10231 at 1.3g/mL. The result of the cytotoxic test against tumor cell line T47D, the lowest IC50 was found in Penicillium sp fungi with 111g/mL value. Aspergillus flavus strain MC-10-L fungi, Penicillium sp, and Aspergillus fumigatus obtained from sponge isolation Stylissa flabelliformis have antimicrobial and cytotoxic activity with various range. All fungi extracts are not toxic against normal cells (Vero cells). The class of compounds in ethyl acetate fungi extract Trichoderma reesei strain JCM 2267 are mostly cyclohexane.

Distinct Miscanthus lignocellulose improves fungus secreting cellulases and xylanases for consistently enhanced biomass saccharification of diverse bioenergy crops

Bioenergy crops provide enormous renewable biomass resources convertible for biofuel production, but lignocellulose recalcitrance fundamentally determines its enzymatic saccharification at high cost and low efficiency. In this study, total 30 diverse Miscanthus lignocellulose substrates were incubated with T. reesei strain to secret lignocellulose-degradation enzymes, and their major wall polymers features (cellulose crystallinity, hemicellulose arabinose and lignin H-monomer) were meanwhile examined with distinct impacts on the enzyme activities. Using characteristic Miscanthus (Msi62) de-lignin residue as inducing substrate with the reesei strain, this study detected that the Msi62-induced enzymes were of consistently higher enhancements on enzymatic saccharification of various lignocellulose residues examined in 17 grassy and woody bioenergy crops, particularly for the hemicellulose hydrolyses, compared to other two reesei-secreted cellulases and three commercial enzymes. Notably, based on SDS-gel protein separation profiling and LC-MS/MS analysis, the Msi62-induced enzymes consist of distinct cellulases (CBHI, BG, EGII) compositions and high-activity xylanases. Therefore, this study has demonstrated an applicable approach to achieve the optimal cellulases and xylanases cocktails that enable for low-costly and high-efficient enzymatic saccharification of diverse lignocellulose sources, providing a potential strategy for large-scale biofuel production in all major bioenergy crops.

Glucose-lactose mixture feeds in industry-like conditions: a gene regulatory network analysis on the hyperproducing Trichoderma reesei strain Rut-C30

BackgroundThe degradation of cellulose and hemicellulose molecules into simpler sugars such as glucose is part of the second generation biofuel production process. Hydrolysis of lignocellulosic substrates is usually performed by enzymes produced and secreted by the fungus Trichoderma reesei. Studies identifying transcription factors involved in the regulation of cellulase production have been conducted but no overview of the whole regulation network is available. A transcriptomic approach with mixtures of glucose and lactose, used as a substrate for cellulase induction, was used to help us decipher missing parts in the network of T. reesei Rut-C30.ResultsExperimental results on the Rut-C30 hyperproducing strain confirmed the impact of sugar mixtures on the enzymatic cocktail composition. The transcriptomic study shows a temporal regulation of the main transcription factors and a lactose concentration impact on the transcriptional profile. A gene regulatory network built using BRANE Cut software reveals three sub-networks related to i) a positive correlation between lactose concentration and cellulase production, ii) a particular dependence of the lactose onto the β-glucosidase regulation and iii) a negative regulation of the development process and growth.ConclusionsThis work is the first investigating a transcriptomic study regarding the effects of pure and mixed carbon sources in a fed-batch mode. Our study expose a co-orchestration of xyr1, clr2 and ace3 for cellulase and hemicellulase induction and production, a fine regulation of the β-glucosidase and a decrease of growth in favor of cellulase production. These conclusions provide us with potential targets for further genetic engineering leading to better cellulase-producing strains in industry-like conditions.