Immobilization Of Cellulase Research Articles

Enhancing cellulose hydrolysis via cellulase immobilization on zeolitic imidazolate frameworks using physical adsorption.

This study investigates the immobilization of cellulase on zeolitic imidazolate frameworks (ZIFs) by physical adsorption, specifically the ZIF-8-NH2 and Fe3O4@ZIF-8-NH2, to enhance enzymatic hydrolysis efficiency. The immobilization process was thoroughly analyzed, including optimization of conditions and characterization of ZIF carriers and immobilized enzymes. The impacts on the catalytic activity of cellulase under various temperatures, pH levels, and storage conditions were examined. Additionally, the reusability of the immobilized enzyme was assessed. Results showed the cellulase immobilized on Fe3O4@ZIF-8-NH2 exhibited a high loading capacity of 339.64 mg/g, surpassing previous studies. Its relative enzymatic activity was found to be 71.39%. Additionally, this immobilized enzyme system demonstrates robust reusability, retaining 68.42% of its initial activity even after 10 cycles. These findings underscore the potential of Fe3O4@ZIF-8-NH2 as a highly efficient platform for cellulase immobilization, with promising implications for lignocellulosic biorefinery.

Enhanced flexibility of high-yield bamboo pulp fibers via cellulase immobilization within guar gum/polyacrylamide/polydopamine interpenetrating network hydrogels

Softness is a crucial criterion in assessing the comfort and usability of tissue paper. Flexible fibers contribute to the softness of the tissue paper by allowing the sheets to conform to the contours of the skin without feeling rough or abrasive. This study focuses on developing innovative CGG/APAM/PDA hydrogels with interpenetrating networks consisting of cationic guar gum, anionic polyacrylamide, and polydopamine for cellulase immobilization, aimed at improving bamboo fiber flexibility. Cellulase biomolecules are efficiently immobilized on CGG/APAM/PDA hydrogels through the Schiff base reaction. Immobilized cellulases have a wider pH applicability than free cellulases, good storage stability, and can maintain high relative activity at relatively high temperatures. The treatment of bamboo fibers with immobilized cellulase results in a significant increase in flexibility, reaching 6.90 × 1014 N·m2, which is 7.18 times higher than that of untreated fibers. The immobilization of cellulases using CGG/APAM/PDA hydrogels as carriers results in a substantial enhancement of storage stability, pH applicability, and inter-fiber bonding strength, as well as the capacity to sustain high relative enzymatic activity at elevated temperatures. The immobilization of cellulase within CGG/APAM/PDA interpenetrating network hydrogels presents a viable strategy for enhancing bamboo fiber flexibility, thereby expanding the accessibility of tissue products.

Evaluation of free and immobilized cellulase on chitosan-modified magnetic nanoparticles for saccharification of sorghum residue.

Enzymatic hydrolysis plays a pivotal role in transforming lignocellulosic biomass. Addressing alternate techniques to optimize the utilization of cellulolytic enzymes is one strategy to improve its efficiency and lower process costs. Cellulases are highly specific and environmentally benign biocatalysts that break down intricate polysaccharides intosimple formsofsugars. In contrast to the most difficult and time-consuming enzyme immobilization processes, in this research, we studied simple, mild, and successful techniques for immobilization of pure cellulase on magnetic nanocomposites using glutaraldehyde as a linker and used in the application of sorghum residue biomass. Fe3O4 nanoparticles were coated with chitosan from the co-precipitation method, which served as an enzyme carrier. The nanoparticles were observed under XRD, Zeta Potential, FESEM, VSM, and FTIR. The size morphology results presented that the Cs@Fe3O4 have 42.2nm, while bare nanoparticles (Fe3O4) have 31.2nm in size. The pure cellulase reaches to 98.07% of loading efficiency and 71.67% of recovery activity at optimal conditions. Moreover, immobilized enzyme's pH stability, thermostability, and temperature tolerance were investigated at suitable conditions. The kinetic parameters of free and immobilized enzyme were estimated as Vmax; 29 ± 1.51 and 27.03 ± 2.02µmolmin-1mg-1, Km; 4.7 ± 0.49mM and 2.569 ± 0.522mM and Kcat; 0.13s-1, and 0.89s-1. Sorghum residue was subjected to 2% NaOH pre-treatment at 50℃. Pre-treated biomass contains cellulose of 64.8%, used as a raw material to evaluate the efficiency of reducing sugar during hydrolysis and saccharification of free and immobilized cellulase, which found maximum concentration of glucose 5.42g/L and 5.12g/L on 72h. Thus, our study verifies the use of immobilized pure cellulase to successfully hydrolyze raw material, which is a significant advancement in lignocellulosic biorefineries and the reusability of enzymes.

Functionalized magnetic nanoparticles for Cellic Ctec2 cellulase immobilization: Allowing reusability of enzyme in the conversion of cellulosic biomass

The method of enzyme immobilization can ameliorate the overall stability and restoration of enzymes, hence facilitating their broader application in several sectors. This investigation utilized cellulase as a hydrolytic enzyme. In order to enhance the stability and performance of the cellulase enzyme, the research employed immobilization technology to secure the Cellic Ctec2 cellulase to the synthesized Cs@Fe3O4 nanocomposites. Fe3O4 nanoparticles (NPs) were coated with chitosan obtained from co-precipitation method that served as enzyme carrier. The NPs (Cs@ Fe3O4) were observed under XRD; VSM (vibrating-sample magnetometer) shows saturation magnetizations (Ms), UV–vis, field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FT-IR). Response surface approach was applied to optimize the conditions for immobilization of cellulase. The optimum immobilization of cellulase reaches to 99.1% of loading efficiency and 69.7% of recovery activity with 2.5% of glutaraldehyde concentration. Furthermore, under ideal circumstances the immobilized enzyme’s thermostability, pH stability, temperature tolerance and reusability, were studied with respect to free cellulase. Higher relative activity of cellulase enzyme was observed at pH 5 with 50 °C temperature than free enzyme. One percent CMC hydrolysis is considered for reusability of free and immobilized enzyme and releases 222 mg glucose/g substrate at 24 h, showing great quiescence in cellulosic biomass conversion. Immobilized cellulase demonstrated high reusability by retaining almost 61.2% up to the 5th cycles and 51.2% of activity-maintained 10th cycle of hydrolysis. Reusability of cellulase enzyme can attain a gradual decrease in relative activity as number of repeats of the cycle increases to 10 during hydrolysis and increases in glucose yield after hydrolysis.

Elucidation of enhanced cellulase immobilization onto synthetic magnetic nickel nanomaterials for lignocellulosic biomass hydrolysis

The immobilization of cellulase enzymes for the conversion of lignocellulosic biomass into sustainable biochemical products is essential for the stability and recovery of the enzymes. In this study, nickel nanoparticles (NiNPs) were synthesized and coated with 3-aminopropyl triethoxysilane (APTES) to serve as cellulase enzyme carriers. Cellulase enzyme immobilization on the prepared NiNPs was achieved using glutaraldehyde as a cross-linker. The physicochemical properties of the carrier were determined before and after enzyme immobilization using X-ray Powder Diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Vibrating-Sample Magnetometer (VSM), and Field Emission Scanning Electron Microscopy (FESEM). The impacts of different experimental factors on the performance of the cellulase enzymes immobilized on the synthesized NiNPs and commercial nickel nanoparticles were compared. The results showed comparable optimal cellulase enzyme immobilization conditions on both substrates in terms of the immobilization time, pH, and cellulase enzyme concentration. However, the recommended temperatures for cellulase enzyme immobilization on the synthesized and commercial NiNPs were 50 °C and 40 °C, respectively. Under these optimum conditions, the immobilized cellulase enzyme on the synthesized NiNPs had an activity of about 99.1% (in comparison to the activity of free cellulase enzyme), while the activity of the enzyme upon immobilization on commercial NiNPs was about 93%. The particle size of the NiNPs was found to be crucial for enzyme immobilization efficiency and its magnetic strength. Therefore, cellulase enzyme immobilization on tunable NiNPs could be a sustainable and eco-friendly approach towards high recovery of cellulose from lignocellulosic materials.

Fungal cellulolytic enzyme complex immobilized on chitosan-functionalised magnetic nanoparticles for paddy straw saccharification

Utilization of biopolymeric functionalized nanocomposites for enzyme immobilization has been actively explored for their potential role as catalysts in sustainable agro-residue valorization models. In the present study, cellulase immobilization on control and chitosan functionalized magnetic nanoparticles (c-MNP & Ch-MNP, respectively) was investigated. A cellulase binding efficiency of 67.50% on c-MNP and 74.06% on Ch-MNP was achieved. The enzyme immobilization on nano-supports was confirmed using electron microscopic and spectroscopic techniques. The immobilized cellulase (E-Ch-MNP) exhibited carboxymethyl cellulase, cellobiase and avicelase specific activities of 48.68, 25.98 and 33.80 nmol min−1 mg−1 protein. The optimum pH for free and immobilized enzyme were reported to be pH 5 and 6, respectively. An increased thermal stability for E-Ch-MNP was observed over a broader temperature range with a peak relative enzyme activity at 60℃. The binding constant (Km= 5.00 mg ml−1) and maximal rate of reaction (Vmax= 0.12 µmol min−1 ml−1) were also determined for E-Ch-MNP. Molecular docking studies determined the flexibilities of both the receptor cellulase protein and the ligand immobilization support molecules with respect to the binding energy and inhibition constants, reflecting their desired conformation and stability. Maximum reducing sugar content of 242.14 mg g−1 of pre-treated straw was reported at 96 h of incubation for E-Ch-MNP with a saccharification efficiency of 35.78%. The retained relative activity of immobilized cellulase was 82.83, 75.17, 44.61 and 27.95% of initial activity after second, third, fourth and fifth cycle, respectively. Therefore, immobilization of cellulase on chitosan coated magnetic nanoparticles holds promise for further optimization for improved cellulose hydrolysis.

Coupling chemical modification and immobilization of cellulase improves thermal stability and low-melting mixture solvent tolerance for in situ saccharification of bagasse

In situ saccharification of lignocellulosic biomass in low-melting mixture solvents (LoMMSs) is a promising approach for biorefinery. In this study, chemical modification of cellulase coupled with immobilization was designed to improve thermal stability and LoMMS tolerance of cellulase for in situ saccharification. Cellulase was firstly chemically modified with succinic anhydride and ethylenediamine respectively to form succinylated cellulase (S-Ce) and aminated cellulase (A-Ce), then the modified cellulases were immobilized with amino-functionalized metal-organic frameworks to establish ZIF-8/A immobilized A-Ce and S-Ce. Circular dichroism, fluorescence measurements, X-ray diffraction, fourier transform infrared spectra and scanning electron microscopy were applied to characterize the modified cellulase or immobilization carrier. ZIF-8/A immobilized A-Ce presented desired thermal stability and LoMMS tolerance. Reducing sugar yields via ZIF-8/A immobilized A-Ce during in situ saccharification of bagasse maintained stably till Bet/AA concentration reached 50%, and declined relatively slowly compared with free or other immobilized cellulase when Bet/AA concentration further increased to 90%. In situ saccharification of bagasse via ZIF-8/A immobilized A-Ce in concentrated Bet/AA (50%) can be operated at a wide temperature range (50–60 °C). The corresponding reducing sugar yield with ZIF-8/A immobilized A-Ce was 58% higher than that with free cellulase in 50% Bet/AA at 60 °C.

Immobilization and Characterization of a Processive Endoglucanase EG5C-1 from Bacillus subtilis on Melamine-Glutaraldehyde Dendrimer-Functionalized Magnetic Nanoparticles.

Exploring an appropriate immobilization approach to enhance catalytic activity and reusability of cellulase is of great importance to reduce the price of enzymes and promote the industrialization of cellulose-derived biochemicals. In this study, Fe3O4 magnetic nanoparticles (MNPs) were functionalized with meso-2,3-dimercaptosuccinic acid to introduce carboxyl groups on the surface (DMNPs). Then, melamine-glutaraldehyde dendrimer-like polymers were grafted on DMNPs to increase protein binding sites for the immobilization of processive endoglucanase EG5C-1. Moreover, this dendrimer-like structure was beneficial to protect the conformation of EG5C-1 and facilitate the interaction between substrate and active center. The loading capacity of the functionalized copolymers (MG-DMNPs) for EG5C-1 was about 195 mg/g, where more than 90% of the activity was recovered. Immobilized EG5C-1 exhibited improved thermal stability and increased tolerability over a broad pH range compared with the free one. Additionally, MG-DMNP/EG5C-1 biocomposite maintained approximately 80% of its initial hydrolysis productivity after five cycles of usage using filter paper as the substrate. Our results provided a promising approach for the functionalization of MNPs, enabling the immobilization of cellulases with a high loading capacity and excellent activity recovery.

Magnetically separable graphene oxide as a promising matrix for cellulase immobilization: enhanced activity and stability with high glucose yield

Magnetically separable graphene oxide as a promising matrix for cellulase immobilization: enhanced activity and stability with high glucose yield

Hybrid Nano Supports of Nano Polyaniline, Magnetic Iron Oxide Nanoparticles and Nano Clay as Matrices for The Immobilization of β-Glucosidase, Fructosyltransferase and Carboxymethyl Cellulase

Hybrid Nano Supports of Nano Polyaniline, Magnetic Iron Oxide Nanoparticles and Nano Clay as Matrices for The Immobilization of β-Glucosidase, Fructosyltransferase and Carboxymethyl Cellulase

Cellulase immobilization on zeolitic imidazolate frameworks for boosting cellulose hydrolysis at high solids loading

This study investigates the cellulase immobilization onto zeolitic imidazolate frameworks (ZIFs) to enable efficient cellulose hydrolysis at high solids loading. Different ZIF carriers (ZIF-8, ZIF-8-NH2, Fe3O4@ZIF-8, and Fe3O4@ZIF-8-NH2) were prepared and characterized. The resulting ZIF-immobilized cellulases were subsequently analyzed for their loading capacity and enzyme activity, as well as their biochemical properties such as temperature stability, pH stability, storage stability, enzyme leaching, and enzyme kinetics. Results revealed that the cellulase immobilized on Fe3O4@ZIF-8-NH2 exhibited an exceptional loading capacity of 359.89 mg/g and a relative enzyme activity of 69.39%. Remarkably, at a solid loading of 15% (w/w) and an enzyme dosage of 5 FPU/g cellulose, the Fe3O4@ZIF-8-NH2 immobilized cellulase demonstrated a 20.44% higher hydrolysis yield compared to the free cellulase. Furthermore, this immobilized enzyme system displayed robust reusability, retaining 71.03% of its initial activity even after 10 cycles of reuse. A proposed mechanism of enhanced enzymatic hydrolysis by ZIF-immobilized cellulases was also presented. These findings have significant implications for the future application of ZIF-immobilized cellulases in efficient and cost-effective lignocellulosic bioconversion.

Polydopamine modified cellulose nanocrystals (CNC) for efficient cellulase immobilization towards advanced bamboo fiber flexibility and tissue softness

Herein, a green facile approach to improve the flexibility of unbleached bamboo kraft pulp (UBKP) via an immobilized enzyme technology is proposed. Polydopamine (PDA) acts as versatile modification and coating materials of cellulose nanocrystals (CNC) for assembling versatile bio-carriers (PDA@CNC). Cellulase biomacromolecules are efficiently immobilized on PDA@CNC to form cellulase@PDA@CNC nanocomposites. The relative enzyme activity, temperature/pH tolerance, and storage stability of cellulase were significantly improved after immobilization. The degree of polymerization treated UBKP decreased by 5.42 % (25 U/g pulp) compared to the control sample. The flexibility of treated fibers was 6.61 × 1014/(N·m2), which was 96.93 % higher (25 U/g) compared to the control and 3.88 times higher than that of the blank fibers. Cellulase@PDA@CNC performs excellent accessibility to fiber structure and induces high degree of fibrillation and hydrolysis of UBKP fibers, which contributes high softness of obtained tissue handsheets. The bio-carrier PDA@CNC within paper framework may further enhance tissue tensile strength. This study proposes a practical and environmentally friendly immobilization approach of cellulase@PDA@CNC for improving the hydrolysis efficiency and flexibility of UBKP fibers, which provides the possibility to maintain the strength of tissue paper while improving its softness, thus broadening the high-value application of immobilized enzyme technology in tissue production.

Functionalized iron oxide nanoparticles for covalent immobilization of cellic CTec2 cellulase: enabling enzyme reusability in cellulosic biomass conversion

A modified chemical co-precipitation method was employed to synthesize silicacoated-aminefunctionalized iron oxide nanoparticle (IONP@SiO2-NH2) which has been utilized as an anchoring surface for enzyme immobilization. Cellulase Cellic CTec2 cocktail was immobilized covalently onto IONP@SiO2-NH2 using glutaraldehyde as a linker. The morphological, structural, and compositional studies of nanoparticles were characterized by field emission scanning electron microscopy with energy dispersive X-ray (FESEM)-EDX, Fourier transform infrared (FTIR), X-ray diffraction (XRD), zeta potential, and Ultraviolet/visible (UV-Vis) spectroscopy. The FTIR, FESEM, and XRD spectra confirmed the successful immobilization of cellulase onto IONP@SiO2-NH2. The free enzymewith cellulase activity of 127 FPU/mL was optimized for the immobilization process which showed the best binding efficiency at 2% glutaraldehyde, protein loading 100 mg/g with carboxymethyl cellulase activity of 290 IU/g, and total immobilization yield of 70.8%. The immobilized cellulase exhibited enhanced stability for temperature and pH over a broader rangethan the free enzyme. The immobilized enzyme-mediated hydrolysis of 1% carboxymethyl cellulose (CMC) released 0.54 g glucose/g substrate at 24 h, showing potential for cellulosic biomass conversion. The immobilized cellulase which was investigated for reusability assay retained∼80% activity even after repeated 6 cycles of CMC hydrolysis. The results showed good reusability after magnetic separation, which is the main advantage of using this nanobiocatalyst system.

Immobilization of Cellulase Enzymes on Single-Walled Carbon Nanotubes for Recycling of Enzymes and Better Yield of Bioethanol Using Computer Simulations.

The utilization of microbial cellulase enzymes for transforming plant biomass into biofuel or bioethanol, which can serve as a substitute for fossil fuel, is a subject of growing interest. Nonetheless, large-scale production of biofuel using cellulases is not economically feasible as the extraction of these enzymes from diverse microorganisms is an expensive process. To address this issue, immobilizing the enzyme to a substrate material, e.g., carbon nanotubes (CNTs), to recycle without a significant decline in its catalytic activity is a promising solution. Due to the hydrophobic nature of CNTs, we employed molecular docking and network analysis methodologies to identify potential CNT-binding sites on the outer surface of a wild-type cellulase enzyme, CelS. Classical molecular dynamics simulations of CNT-bound CelS through one of the selected binding sites resulted in negligible changes in the secondary structure of the enzyme and its catalytic domain, implying the least possible effect on the catalytic activity post-immobilization. Furthermore, our study reveals that while the unfolding near the CNT-binding region in CelS is more pronounced when the enzyme is interacting with a wider CNT, resulting in enhanced contact area and improved binding affinity, its impact on the overall CelS structure is relatively less significant when compared to thinner CNTs. Particularly, CNTs of diameter ∼12 Å can serve as a favorable option for substrate materials in cellulase immobilization. Our study also provides critical insights into the binding mechanisms between cellulase and CNTs, which could lead to the development of more efficient biocatalysts for biofuel production.

Faujasite Na-X zeolite as a novel carrier for cellulase immobilization and application in biomass saccharification

As a sustainable and eco-friendly alternative to conventional chemical catalysis, the immobilization of enzymes has been advocated as an attractive strategy to offset the limitations of single-use and rapid loss of activity. The present study aimed to investigate an inert inorganic material, i.e. Na-X zeolite derived from fly ash as a solid carrier for the immobilization of cellulase, a pivotal enzyme for biomass valorization. The cellulase enzyme (Cellic CTec2) was covalently immobilized over Na-X zeolite using glutaraldehyde as a cross-linking agent with immobilization efficiency and yield of 73% and 77%, respectively. The immobilized cellulase exhibited better pH stability (5.0–9.0), temperature optima of 60 °C, and a three-fold half-life (t1/2) enhancement at 60 °C than its free counterpart. The immobilized preparation retained > 80% residual activity after 5 repeated cycles of usage and had enhanced shelf life, as reflected by good storage stability at both 4 °C and 22 °C after 4 weeks of incubation. The immobilized formulation was utilized to saccharify alkaline pretreated wheat straw to demonstrate its potential for biorefinery applications, and structural deconstruction was validated by SEM, XRD, and FTIR analysis. The high reducing sugar yield for two consecutive cycles confirms its suitability for continuous operation in hydrolyzing lignocellulosic substrates.

Evaluation of the alternating magnetic field (AMF) influence in catalytic activities of enzymes immobilized into magnetic graphene oxide: A new approach

The conventional methods of production of biofuels generate hazardous by-products, one way to reduce them, by using reusable enzymatic process that requires insoluble enzyme carriers. This investigation allowed the obtention of magnetic graphene oxide (MGO) carrier containing aminosilane functional groups with and without the crosslinker glutaraldehyde. Thus, it was possible to immobilize cellulases and lipases enzymes and evaluate its enzymatic activity in normal conditions, as well as the novelty that was under alternating magnetic field (AMF) conditions. Through enzymatic essays it was determined the optimal working activities for both enzymes using these two magnetic carriers, being pH 4 and 60ºC for cellulases and pH 5 and 50ºC for lipase. Different frequencies were used during AMF test (20, 30, 50 and 70 kHz) and it was confirmed for both groups that with the increase in frequency during the reaction, the less pronounced will be the activity decrease at pH values different from the optimal condition. Due to magnetic properties from the carrier and the medium reaction used the recycle test was satisfactory for the two immobilized groups of the cellulase enzyme, being recycled 9 times without losses greater than 50 % of relative activity. As for the two groups of immobilized lipases, drastic decreases in activity were observed, possibly caused by the strong enzyme/substrate interaction. For both groups of immobilized enzymes, an inhibitory behavior of the glutaraldehyde reagent, widely used as an enzyme/carrier cross-linker, was also observed. Nevertheless, the immobilization of cellulase and lipases enzymes into MGO derivates shows a promising and suitable strategy for the conversion of cellulose and long-chain acyl esters into value-added inputs.

Cellulase-immobilized chitosan-coated magnetic nanoparticles for saccharification of lignocellulosic biomass.

Devising and consolidating cost-effective and greener technologies for sustainable energy production pertain to some of the most pressing needs of the present times. Bioconversion of abundantly available lignocellulosic materials into fermentable sugars to produce biofuels involves the cost-extensive requirement of hydrolytic enzymes called cellulases. Cellulases are highly selective and eco-friendly biocatalysts responsible for deconstruction of complex polysaccharides into simple sugars. Currently, immobilization of cellulases is being carried out on magnetic nanoparticles functionalized with suitable biopolymers such as chitosan. Chitosan, a biocompatible polymer, exhibits high surface area, chemical/thermal stability, functionality, and reusability. The chitosan-functionalized magnetic nanocomposites (Ch-MNCs) present a nanobiocatalytic system that enables easy retrieval, separation, and recycling of cellulases, thereby offering a cost-effective and sustainable approach for biomass hydrolysis. These functional nanostructures show enormous potential owing to certain physicochemical and structural features that have been discussed in a comprehensive manner in this review. It provides an insight into the synthesis, immobilization, and application of cellulase immobilized Ch-MNCs for biomass hydrolysis. This review aims to bridge the gap between sustainable utilization and economic viability of employing replenishable agro-residues for cellulosic ethanol production by incorporating the recently emerging nanocomposite immobilization approach.

Immobilization of cellulase on graphene oxide coated with NiFe2O4 and Fe3O4 for hydrolysis of rice straw

Immobilization of cellulase on graphene oxide coated with NiFe2O4 and Fe3O4 for hydrolysis of rice straw

The controlled degradation of bacterial cellulose in simulated physiological environment by immobilization and release of cellulase

Bacterial cellulose (BC) has good network structure, biocompatibility, and excellent mechanical properties, and is widely used in the field of biomaterials. The controllable degradation of BC can further broaden its application. Oxidative modification and cellulases may endow BC with degradability, but these methods inevitably lead to the obvious reduction of its initial mechanical properties and uncontrolled degradation. In this paper, the controllable degradation of BC was realized for the first time by using a new controlled release structure that combines the immobilization and release of cellulase. The immobilized enzyme has higher stability and is gradually released in the simulated physiological environment, and its load can control the hydrolysis rate of BC well. Furthermore, the BC-based membrane prepared by this method retains the favorable physicochemical performance of the original BC, including flexibility and great biocompatibility, and holds good application prospects in drug control release or tissue repair.

A study on critical associations of media components on enhanced cellulase production from wild Trichoderma viride and cellulase immobilization on iron-oxide magnetic nanoparticles

Aim: The current study is a preliminary step towards enhancing the cellulase productivity in wild Trichoderma viride which will enable robust valorization of non-edible lignocellulosic biomass through co-generative enzymatic saccharification, specifically concentrating on influence of individual media components on biomass growth and cellulase productivity. Further, cellulase immobilization on iron-oxide magnetic nanoparticles was also achieved that can increase the shelf life of the enzyme. Methodology: The cellulase production in the wild Trichoderma viride was enhanced using media design and formulation. EDC {1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide} functionalized iron-oxide nanoparticles were chosen to act as carriers for cellulase immobilization. The binding efficiency and relative activity were measured in addition to optimal pH and temperature for cellulase bound iron-oxide nanoparticles. Further, the hydrolysis efficiency of immobilized cellulases was also measured after which it was subjected to consecutive hydrolytic cycles to calculate the recycle rate. Results: A maximum growth rate of 60 PCV (Packed cell volume) and total cellulase activity of 7.4 U ml-1 was obtained on media design and formulation. 82.5% binding efficiency was achieved on EDC functionalized iron-oxide magnetic nanoparticles which showed good stability at 5pH and 500C. There was 44.4% activity loss after 5 consecutive hydrolytic cycles which showed steady decline with increased cycle number and finally at the end of the 10th hydrolytic cycle, 22.2% of total relative activity was retained. Interpretation: Unprecedented total cellulase activity from a wild strain was obtained through media design. The stability of cellulases was further enhanced using iron-oxide magnetic nanoparticle immobilization. Key words: Cellulases, Immobilization, Iron-oxide magnetic nanoparticles, Submerged fermentation, Trichoderma viride