|In 3.2 M ammonium sulphate
|> 1 year under recommended storage conditions
|cellulose 1,4-beta-cellobiosidase (non-reducing end); 4-beta-D-glucan cellobiohydrolase (non-reducing end)
|Supplied at ~ 0.1 U/mg
|Purified from Trichoderma longibrachiatum
|Hydrolysis of (1,4)-β-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains. Active on pNP β-lactoside.
|~ 0.1 U/mg (40oC, pH 4.5 on p-nitrophenyl-β-lactoside).
|One Unit of cellobiohydrolase I activity is defined as the amount of enzyme required to release one µmole of p-nitrophenol (pNP) per minute from p-nitrophenyl-β-lactoside (2.5 mg/mL) in sodium acetate buffer (100 mM), pH 4.5 and 40oC.
|Applications established in diagnostics and research within the textiles, food and feed, carbohydrate and biofuels industries.
High purity Cellobiohydrolase I (Trichoderma longibrachiatum) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
Carbohydrate-binding modules enhance H2O2 tolerance by promoting lytic polysaccharide monooxygenase active site H2O2 consumption.
Gao, W., Li, T., Zhou, H., Ju, J. & Yin, H. (2024). Journal of Biological Chemistry, 300(1), 105573.
Lytic polysaccharide monooxygenases (LPMOs) oxidatively depolymerize recalcitrant polysaccharides, which is important for biomass conversion. The catalytic domains of many LPMOs are linked to carbohydrate-binding modules (CBMs) through flexible linkers, but the function of these CBMs in LPMO catalysis is not well understood. In this study, we utilized MtLPMO9L and MtLPMO9G derived from Myceliophthora thermophila to investigate the impact of CBMs on LPMO activity, with particular emphasis on their influence on H2O2 tolerance. Using truncated forms of MtLPMO9G generated by removing the CBM, we found reduced substrate binding affinity and enzymatic activity. Conversely, when the CBM was fused to the C terminus of the single-domain MtLPMO9L to create MtLPMO9L-CBM, we observed a substantial improvement in substrate binding affinity, enzymatic activity, and notably, H2O2 tolerance. Furthermore, molecular dynamics simulations confirmed that the CBM fusion enhances the proximity of the active site to the substrate, thereby promoting multilocal cleavage and impacting the exposure of the copper active site to H2O2. Importantly, the fusion of CBM resulted in more efficient consumption of H2O2 by LPMO, leading to improved enzymatic activity and reduced auto-oxidative damage of the copper active center.Hide Abstract
Isolation and modification of nano-scale cellulose from organosolv-treated birch through the synergistic activity of LPMO and endoglucanases.
Muraleedharan, M. N., Karnaouri, A., Piatkova, M., Ruiz-Caldas, M. X., Matsakas, L., Liu, B., Rova, U., Christakopoulos, P. & Mathew, A. P. (2021). International Journal of Biological Macromolecules, 183, 101-109.
Nanocellulose isolation from lignocellulose is a tedious and expensive process with high energy and harsh chemical requirements, primarily due to the recalcitrance of the substrate, which otherwise would have been cost-effective due to its abundance. Replacing the chemical steps with biocatalytic processes offers opportunities to solve this bottleneck to a certain extent due to the enzymes substrate specificity and mild reaction chemistry. In this work, we demonstrate the isolation of sulphate-free nanocellulose from organosolv pretreated birch biomass using different glycosyl-hydrolases, along with accessory oxidative enzymes including a lytic polysaccharide monooxygenase (LPMO). The suggested process produced colloidal nanocellulose suspensions (ζ-potential -19.4 mV) with particles of 7-20 nm diameter, high carboxylate content and improved thermostability (To = 301°C, Tmax = 337°C). Nanocelluloses were subjected to post-modification using LPMOs of different regioselectivity. The sample from chemical route was the least favorable for LPMO to enhance the carboxylate content, while that from the C1-specific LPMO treatment showed the highest increase in carboxylate content.Hide Abstract
Valorization of outer tunic of the marine filter feeder Ciona intestinalis towards the production of second-generation biofuel and prebiotic oligosaccharides.
Hrůzová, K., Matsakas, L., Karnaouri, A., Norén, F., Rova, U. & Christakopoulos, P. (2021). Biotechnology for Biofuels, 14(1), 1-8.
Background: One of the sustainable development goals focuses on the biomass-based production as a replacement for fossil-based commodities. A novel feedstock with vast potentials is tunicate biomass, which can be pretreated and fermented in a similar way to lignocellulose. Ciona intestinalis is a marine filter feeder that is cultivated to produce fish feed. While the inner tissue body is used for feed production, the surrounding tunic remains as a cellulose-rich by-product, which can be further separated into outer and inner tunic. Ethanol production from organosolv-pretreated whole-tunic biomass was recently validated. The aim of the present study was to evaluate the potential of organosolv pretreated outer-tunic biomass for the production of biofuels and cellobiose that is a disaccharide with prebiotic potential. Results: As a result, 41.4 g/L of ethanol by Saccharomyces cerevisiae, corresponding to a 90.2% theoretical yield, was achieved under the optimal conditions when the tunicate biomass was pretreated at 195°C for 60 min at a liquid-to-solid ratio of 50. In addition, cellobiose production by enzymatic hydrolysis of the pretreated tunicate biomass was demonstrated with a maximum conversion yield of 49.7 wt. %. Conclusions: The utilisation of tunicate biomass offers an eco-friendly and sustainable alternative for value-added biofuels and chemicals. The cultivation of tunicate biomass in shallow coastal sea improves the quality of the water and ensures sustainable production of fish feed. Moreover, there is no competition for arable land, which leaves the latter available for food and feed production.Hide Abstract
Adsorption behavior of two glucanases on three lignins and the effect by adding sulfonated lignin.
Zhang, Y., Jiang, X., Wan, S., Wu, W., Wu, S. & Jin, Y. (2020). Journal of Biotechnology, 323, 1-8.
The adsorption behaviors of two glucanases, TvEG and TrCel7A, on three lignins were investigated. Three lignins were isolated from raw aspen and its pretreated solid residue. The isolated lignins were labeled as Asp-MWL, DA-MWL (pretreated by dilute acid), and GL-MWL (pretreated by green liquor), respectively. The surface properties of lignins and spin-coated lignin films were characterized by zeta potential, atomic force microscope (AFM) and contact angle. The enzyme adsorption behavior was monitored by quartz crystal microbalance (QCM) and fluorescence spectrometer. TlCel7A had similar adsorption capacities on the three lignin films but were higher than those of TvEG. The TrCel7A adsorptions on the three lignin films were affected by synergistic effect of electrostatic and hydrophobic interaction while the TvEG adsorptions on the three lignin films were mainly dominated by hydrophobic action. The adsorption capacities of TlCel7A and TvEG on the three lignin films were decreased by adding SL. Plausible explanation was that the SL and glucanase formed a complex with more negative charges, which suppressed the adsorption of glucannase on lignin through electrostatic repulsion. It also explained the improved enzymatic hydrolysis efficiency of lignocellulose upon adding SL.Hide Abstract
A simple enzymatic assay for the quantification of C1-specific cellulose oxidation by lytic polysaccharide monooxygenases.
Keller, M. B., Felby, C., Labate, C. A., Pellegrini, V. O. A., Higasi, P., Singh, R. K., Polikarpov, I. & Blossom, B. M. (2020). Biotechnology Letters, 42(1), 93-102.
Objective: The development of an enzymatic assay for the specific quantification of the C1-oxidation product, i.e. gluconic acid of cellulose active lytic polysaccharide monooxygenases (LPMOs). Results: In combination with a β-glucosidase, the spectrophotometrical assay can reliably quantify the specific C1-oxidation product of LPMOs acting on cellulose. It is applicable for a pure cellulose model substrate as well as lignocellulosic biomass. The enzymatic assay compares well with the quantification performed by HPAEC-PAD. In addition, we show that simple boiling is not sufficient to inactivate LPMOs and we suggest to apply a metal chelator in addition to boiling or to drastically increase pH for proper inactivation. Conclusions: We conclude that the versatility of this simple enzymatic assay makes it useful in a wide range of experiments in basic and applied LPMO research and without the need for expensive instrumentation, e.g. HPAEC-PAD.Hide Abstract
A lytic polysaccharide monooxygenase from Myceliophthora thermophila and its synergism with cellobiohydrolases in cellulose hydrolysis.
Zhou, H., Li, T., Yu, Z., Ju, J., Zhang, H., Tan, H., Li, K. & Yin, H. (2019). International Journal of Biological Macromolecules, 139, 570-576.
Lytic polysaccharide monooxygenases (LPMOs) have attracted vast attention because of their unique mechanism of oxidative degradation of carbohydrate polymers and the potential application in biorefineries. This study characterized a novel LPMO from Myceliophthora thermophila, denoted MtLPMO9L. The structure model of the enzyme indicated that it belongs to the C1-oxidizing LPMO, which has neither an extra helix in the L3 loop nor extra loop region in the L2 loop. This was confirmed subsequently by the enzymatic assays since MtLPMO9L only acts on cellulose and generates C1-oxidized cello-oligosaccharides. Moreover, synergetic experiments showed that MtLPMO9L significantly improves the efficiency of cellobiohydrolase (CBH) II. In contrast, the inhibitory rather than synergetic effect was observed when combining used MtLPMO9L and CBHI. Changing the incubation time and concentration ratio of MtLPMO9L and CBHI could attenuate the inhibitory effects. This discovery suggests a different synergy detail between MtLPMO9L and two CBHs, which implies that the composition of cellulase cocktails may need reconsideration.Hide Abstract
An engineered GH1 β-glucosidase displays enhanced glucose tolerance and increased sugar release from lignocellulosic materials.
Santos, C. A., Morais, M. A., Terrett, O. M., Lyczakowski, J. J., Zanphorlin, L. M., Ferreira-Filho, J. A., Tonoli, C. C. C., Murakami, M. T., Dupree, P. & Souza, A. P. (2019). Scientific Reports, 9(1), 1-10.
β-glucosidases play a critical role among the enzymes in enzymatic cocktails designed for plant biomass deconstruction. By catalysing the breakdown of β-1, 4-glycosidic linkages, β-glucosidases produce free fermentable glucose and alleviate the inhibition of other cellulases by cellobiose during saccharification. Despite this benefit, most characterised fungal β-glucosidases show weak activity at high glucose concentrations, limiting enzymatic hydrolysis of plant biomass in industrial settings. In this study, structural analyses combined with site-directed mutagenesis efficiently improved the functional properties of a GH1 β-glucosidase highly expressed by Trichoderma harzianum (ThBgl) under biomass degradation conditions. The tailored enzyme displayed high glucose tolerance levels, confirming that glucose tolerance can be achieved by the substitution of two amino acids that act as gatekeepers, changing active-site accessibility and preventing product inhibition. Furthermore, the enhanced efficiency of the engineered enzyme in terms of the amount of glucose released and ethanol yield was confirmed by saccharification and simultaneous saccharification and fermentation experiments using a wide range of plant biomass feedstocks. Our results not only experimentally confirm the structural basis of glucose tolerance in GH1 β-glucosidases but also demonstrate a strategy to improve technologies for bioethanol production based on enzymatic hydrolysis.Hide Abstract
Song, B., Li, B., Wang, X., Shen, W., Park, S., Collings, C., Feng, A., Smith, S. J., Walton, J. D. W. & Ding, S. Y. (2018). Biotechnology for Biofuels, 11(1), 41.
Background: The high cost of enzymes is one of the key technical barriers that must be overcome to realize the economical production of biofuels and biomaterials from biomass. Supplementation of enzyme cocktails with lytic polysaccharide monooxygenase (LPMO) can increase the efficiency of these cellulase mixtures for biomass conversion. The previous studies have revealed that LPMOs cleave polysaccharide chains by oxidization of the C1 and/or C4 carbons of the monomeric units. However, how LPMOs enhance enzymatic degradation of lignocellulose is still poorly understood. Results: In this study, we combined enzymatic assays and real-time imaging using atomic force microscopy (AFM) to study the molecular interactions of an LPMO [TrAA9A, formerly known as TrCel61A) from Trichoderma reesei] and a cellobiohydrolase I (TlCel7A from T. longibrachiatum) with bacterial microcrystalline cellulose (BMCC) as a substrate. Cellulose conversion by TlCel7A alone was enhanced from 46 to 54% by the addition of TrAA9A. Conversion by a mixture of TlCel7A, endoglucanase, and β-glucosidase was increased from 79 to 87% using pretreated BMCC with TrAA9A for 72 h. AFM imaging demonstrated that individual TrAA9A molecules exhibited intermittent random movement along, across, and penetrating into the ribbon-like microfibril structure of BMCC, which was concomitant with the release of a small amount of oxidized sugars and the splitting of large cellulose ribbons into fibrils with smaller diameters. The dividing effect of the cellulose microfibril occurred more rapidly when TrAA9A and TlCel7A were added together compared to TrAA9A alone; TlCel7A alone caused no separation. Conclusions: TrAA9A increases the accessible surface area of BMCC by separating large cellulose ribbons, and thereby enhances cellulose hydrolysis yield. By providing the first direct observation of LPMO action on a cellulosic substrate, this study sheds new light on the mechanisms by which LPMO enhances biomass conversion.Hide Abstract
Ogunmolu, F. E., Jagadeesha, N. B. K., Kumar, R., Kumar, P., Gupta, D. & Yazdani, S. S. (2017). Biotechnology for Biofuels, 10(71).
Background: GH7 cellobiohydrolases (CBH1) are vital for the breakdown of cellulose. We had previously observed the enzyme as the most dominant protein in the active cellulose-hydrolyzing secretome of the hypercellulolytic ascomycete—Penicillium funiculosum (NCIM1228). To understand its contributions to cellulosic biomass saccharification in comparison with GH7 cellobiohydrolase from the industrial workhorse—Trichoderma reesei, we natively purified and functionally characterized the only GH7 cellobiohydrolase identified and present in the genome of the fungus. Results: There were marginal differences observed in the stability of both enzymes, with P. funiculosum (PfCBH1) showing an optimal thermal midpoint (Tm) of 68°C at pH 4.4 as against an optimal Tm of 65°C at pH 4.7 for T. reesei (TrCBH1). Nevertheless, PfCBH1 had an approximate threefold lower binding affinity (Km), an 18-fold higher turnover rate (kcat), a sixfold higher catalytic efficiency as well as a 26-fold higher enzyme-inhibitor complex equilibrium dissociation constant (Ki) than TrCBH1 on p-nitrophenyl-β-D-lactopyranoside (pNPL). Although both enzymes hydrolyzed cellooligomers (G2–G6) and microcrystalline cellulose, releasing cellobiose and glucose as the major products, the propensity was more with PfCBH1. We equally observed this trend during the hydrolysis of pretreated wheat straws in tandem with other core cellulases under the same conditions. Molecular dynamic simulations conducted on a homology model built using the TrCBH1 structure (PDB ID: 8CEL) as a template enabled us to directly examine the effects of substrate and products on the protein dynamics. While the catalytic triads—EXDXXE motifs—were conserved between the two enzymes, subtle variations in regions enclosing the catalytic path were observed, and relations to functionality highlighted. Conclusion: To the best of our knowledge, this is the first report about a comprehensive and comparative description of CBH1 from hypercellulolytic ascomycete—P. funiculosum NCIM1228, against the backdrop of the same enzyme from the industrial workhorse—T. reesei. Our study reveals PfCBH1 as a viable alternative for CBH1 from T. reesei in industrial cellulase cocktails.Hide Abstract
Kim, I. J., Lee, H. J. & Kim, K. H. (2017). Process Biochemistry, 57, 167-174.
The compositions and physical properties of pretreated lignocellulose vary depending on pretreatment methods; therefore, enzyme cocktails specific to pretreatments are desired for efficient saccharification of lignocellulose. Here, enzyme cocktails consisting of three pure lignocellulolytic enzymes endoglucanase (EG), cellobiohydrolase (CBH) and endoxylanase (XN) with a fixed amount of β-glucosidase were tailored for acid- and alkali-pretreated sugarcane bagasse (ACID and ALKALI, respectively). Based on a mixture design, the optimal mass ratios of EG, CBH, and XN were determined to be 61.25:38.73:0.02 and 53.99:34.60:11.41 for ACID and ALKALI, respectively. The optimized enzyme cocktail yielded a higher or comparable amount of reducing sugars from the hydrolysis of ACID and ALKALI when compared to that obtained using commercial cellulase mixtures. Using the commercial and easily available pure enzymes, this simple method for the in-house preparation of an enzyme cocktail specific to pretreated lignocellulose consisting of only four enzymes with a high level of hydrolysis will be helpful for achieving enzymatic saccharification in the lignocellulose-based biorefinery.Hide Abstract