scholarly journals Metagenomic Discovery and Characterization of Multi-Functional and Monomodular Processive Endoglucanases as Biocatalysts

2021 ◽  
Vol 11 (11) ◽  
pp. 5150
Author(s):  
Ming Z. Fan ◽  
Weijun Wang ◽  
Laurence Cheng ◽  
Jiali Chen ◽  
Wenyi Fan ◽  
...  
Keyword(s):  
Thermotoga Maritima ◽  
Glycosyl Hydrolase ◽  
Industrial Applications ◽  
Carbohydrate Binding ◽  
Expression Library ◽  
Molecular Weights ◽  
Structural And Functional Properties ◽  
Potential Applications ◽  
Spherical Diameter

Biomass includes cellulose, hemicelluloses, pectin and lignin; constitutes the components of dietary fibre of plant and alge origins in animals and humans; and can potentially provide inexhaustible basic monomer compounds for developing sustainable biofuels and biomaterials for the world. Development of efficacious cellulases is the key to unlock the biomass polymer and unleash its potential applications in society. Upon reviewing the current literature of cellulase research, two characterized and/or engineered glycosyl hydrolase family-5 (GH5) cellulases have displayed unique properties of processive endoglucanases, including GH5-tCel5A1 that was engineered and was originally identified via targeted genome sequencing of the extremely thermophilic Thermotoga maritima and GH5-p4818Cel5_2A that was screened out of the porcine hindgut microbial metagenomic expression library. Both GH5-tCel5A1 and GH5-p4818_2A have been characterized as having small molecular weights with an estimated spherical diameter at or < 4.6 nm; being monomodular without a required carbohydrate-binding domain; and acting as processive β-1,4-endoglucanases. These two unique GH5-tCel5A1 and GH5-p4818_2A processive endocellulases are active in hydrolyzing natural crystalline and pre-treated cellulosic substrates and have multi-functionality towards several hemicelluloses including β-glucans, xylan, xylogulcans, mannans, galactomannans and glucomannans. Therefore, these two multifunctional and monomodular GH5-tCel5A1 and GH5-p4818_2A endocellulases already have promising structural and functional properties for further optimization and industrial applications.

scholarly journals Characterization of a New Intracellular Alginate Lyase with Metal Ions-Tolerant and pH-Stable Properties

Marine Drugs ◽  
2020 ◽  
Vol 18 (8) ◽  
pp. 416
Author(s):  
Yan Ma ◽  
Jie Li ◽  
Xin-Yue Zhang ◽  
Hao-Dong Ni ◽  
Feng-Biao Wang ◽  
...  
Keyword(s):  
Metal Ion ◽  
Brown Seaweed ◽  
Alginate Lyase ◽  
Industrial Applications ◽  
Alginate Oligosaccharides ◽  
Potential Applications ◽  
Pharmaceutical Industries ◽  
Ph Range ◽  
Alginate Lyases

Alginate lyases play an important role in alginate oligosaccharides (AOS) preparation and brown seaweed processing. Many extracellular alginate lyases have been characterized to develop efficient degradation tools needed for industrial applications. However, few studies focusing on intracellular alginate lyases have been conducted. In this work, a novel intracellular alkaline alginate lyase Alyw202 from Vibrio sp. W2 was cloned, expressed and characterized. Secretory expression was performed in a food-grade host, Yarrowia lipolytica. Recombinant Alyw202 with a molecular weight of approximately 38.3 kDa exhibited the highest activity at 45 °C and more than 60% of the activity in a broad pH range of 3.0 to 10.0. Furthermore, Alyw202 showed remarkable metal ion-tolerance, NaCl independence and the capacity of degrading alginate into oligosaccharides of DP2-DP4. Due to the unique pH-stable and high salt-tolerant properties, Alyw202 has potential applications in the food and pharmaceutical industries.

scholarly journals Construction of a Novel Chimeric Dextransucrase Fused to the Carbohydrate-Binding Module CBM2a

2021 ◽  
Author(s):  
Reinaldo Fraga Vidal ◽  
Roberto Carlos Aristicas Ribalta ◽  
Lisandra Teresa Martínez Valdés ◽  
Meinardo Lafargue Gámez ◽  
Amanda Montes Alvarez ◽  
...  
Keyword(s):  
Binding Capacity ◽  
Structural Characteristics ◽  
Carbohydrate Binding ◽  
Carbohydrate Binding Module ◽  
Molecular Weights ◽  
Isolation And Characterization ◽  
The Subject ◽  
Encoding Gene ◽  
First Time

The lactic acid bacteria (LAB) have great potential to produce homoexopolysaccharides (HoPS), have been the subject of extensive research efforts, given their health benefits and physicochemical properties. The HoPS functional properties are determined by structural characteristics of varied molecular weights, types of glycosidic linkages, degrees of branching and chemical composition. The dextransucrases (DSases) are responsible of the synthesis of a kind of HoPS (dextran polymers), which are among the first biopolymers produced at industrial scale with applications in medicine and biotechnology. The concept of glycodiversification opens additional applications for DSases. In that sense the design and characterization of new DSases is of prime importance. Previously, we described the isolation and characterization of a novel extracellular dextransucrase (DSR-F) encoding gene. In this study, from DSR-F, we design a novel chimeric dextransucrase DSR-F-∆SP-∆GBD-CBM2a, where DSR-F-∆SP-∆GBD is fused to the carbohydrate-binding module (CBM2a) of the &beta;-1-4 exoglucanase/xylanase Cex (Xyn10A) of Cellulomonas fimi ATCC 484. This dextransucrase variant is active and without alteration in its specificity. The DSR-F-∆SP-∆GBD-CBM2a is purified by cellulose affinity chromatography for the very first time. Our results indicate that new hybrids and chimeric DSases with novel binding capacity to cellulose can be designed to obtain glyco-biocatalysts from renewable lignocellulosic materials.

Characterization of Ammonia–Water Absorption Chiller and Application

2018 ◽  
Vol 26 (04) ◽  
pp. 1850035 ◽  
Author(s):  
Gopalakrishnan Anand ◽  
Donald C. Erickson ◽  
Ellen Makar
Keyword(s):  
Simple Model ◽  
Low Temperatures ◽  
Waste Heat ◽  
Cooling Water ◽  
Industrial Applications ◽  
Absorption Refrigeration ◽  
Potential Applications ◽  
Ammonia Absorption ◽  
Simple Equations

Ammonia-absorption refrigeration units (AARUS) can supply subfreezing refrigeration for many industrial applications. Such units are usually driven by waste heat or renewable energy at relatively low temperatures. The performance of the chiller is highly dependent on the temperatures of the driving heat, the chilling load, and the cooling water. In this paper, the performance of an advanced industrial-scale ammonia-absorption unit is modeled over a representative operating range. The performance is then characterized by a set of simple equations incorporating the three external temperatures. This simple model helps to evaluate potential applications, predict performance, and perform initial optimization. Case studies are presented highlighting the application of the model.

Tick lectins: structural and functional properties

Parasitology ◽  
2004 ◽  
Vol 129 (S1) ◽  
pp. S113-S125 ◽  
Author(s):  
L. GRUBHOFFER ◽  
V. KOVÁŘ ◽  
N. RUDENKO
Keyword(s):  
Functional Properties ◽  
Carbohydrate Binding ◽  
Parasite Transmission ◽  
Ornithodoros Moubata ◽  
Self Recognition ◽  
Structural And Functional Properties ◽  
Defence Reactions ◽  
Derivatives Of ◽  
Plasma Lectin

Few papers have been published on tick lectins so far, and therefore more data are needed to complete the mosaic of knowledge of their structural and functional properties. Tissue-specific lectin/haemagglutinin activities of both soft and hard ticks have been investigated. Some tick lectins are proteins with binding affinity for sialic acid, various derivatives of hexosamines and different glycoconjugates. Most tick lectin/haemagglutinin activities are blood meal enhanced, and could serve as molecular factors of self/non-self recognition in defence reactions against bacteria or fungi, as well as in pathogen/parasite transmission. Dorin M, the plasma lectin ofOrnithodoros moubata, is the first tick lectin purified so far from tick haemolymph, and the first that has been fully characterized. Partial characterization of other tick lectins/haemagglutinins has been performed mainly with respect to their carbohydrate binding specificities and immunochemical features.

Thermodynamic Properties of the β-glucosidase from Thermotoga maritima Extend the Upper Limit of Thermophilicity

2014 ◽  
Vol 21 (12) ◽  
pp. 1282-1288
Author(s):  
Muhammad A. Mehmood ◽  
Izzah Shahid ◽  
Khadim Hussain ◽  
Farooq Latif ◽  
Muhammad I. Rajoka
Keyword(s):  
Hydrophobic Interactions ◽  
Thermotoga Maritima ◽  
Industrial Applications ◽  
Enzyme Inactivation ◽  
Purification And Characterization ◽  
Over Expression ◽  
E Coli ◽  
Gibb’S Free Energy ◽  
Thermophilic Organisms

Enzymes from thermophilic organisms are believed to be strong candidates for industrial applications due to their ability to withstand temperature-induced enzyme inactivation. The present study demonstrated molecular cloning, over-expression, purification and characterization of β-glucosidase from Thermotoga maritima. The bglA gene with a capacity to encode a 51 kDa enzyme was heterologously expressed in E. coli M15. The enzyme was produced @130 mgL-1 in LB media and @440 mgL-1 in Dubos salt medium accounting 40-47 % of total cellular soluble proteins when lactose was used as an inducer. The enzyme showed a peak activity between pH and temperature range of 5.0-7.0 and 80-100 °C, respectively. The activity was fairly stable up to 140 °C. The turnover rate (kcat) of the enzyme was 187.1±20 s-1, whereas the Km and Vmax values were 0.56 mM and 238±2.4 IU mg-1 protein, respectively. The enzyme was shown to have half-life of 136, 71 and 12.6 h at 80, 90 and 100 °C, respectively. Thermodynamics parameters including melting temperature (130 °C), activation energy for inactivation (36.92 kJmole-1), enthalpy (33.73 kJmole-1), Gibb’s free energy (127.96 kJmole-1) and entropy (-246.46 Jmole-1K-1) have shown that the enzyme have enhanced hydrophobic interactions to prevent its thermal unfolding. These features endorse the industrial applications of the enzyme.

scholarly journals Production and characterization of Aspergillus niger GH29 family α-fucosidase and production of a novel non-reducing 1-fucosyllactose

2019 ◽  
Vol 37 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Anne Usvalampi ◽  
Marcela Ruvalcaba Medrano ◽  
Hannu Maaheimo ◽  
Heidi Salminen ◽  
Olli Tossavainen ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Glycosyl Hydrolase ◽  
Temperature Stability ◽  
Hydrolytic Activity ◽  
Industrial Applications ◽  
Optimal Temperature ◽  
Anomeric Carbon ◽  
Substrate Concentrations ◽  
Hydrolase Family

AbstractFucosylated oligosaccharides are interesting molecules due to their bioactive properties. In particular, their application as active ingredient in milk powders is attractive for dairy industries. The objective of this study was to characterize the glycosyl hydrolase family 29 α-fucosidase produced by Aspergillus niger and test its ability to transfucosylate lactose with a view towards potential industrial applications such as the valorization of the lactose side stream produced by dairy industry. In order to reduce costs and toxicity the use of free fucose instead of environmentally questionable fucose derivatives was studied. In contrast to earlier studies, a recombinantly produced A. niger α-fucosidase was utilized. Using pNP-fucose as substrate, the optimal pH for hydrolytic activity was determined to be 3.8. The optimal temperature for a 30-min reaction was 60 °C, and considering temperature stability, the optimal temperature for a 24-h reaction was defined as 45 °C For the same hydrolysis reaction, the kinetic values were calculated to be 0.385 mM for the KM and 2.8 mmol/(mg*h) for the Vmax. Transfucosylation of lactose occurred at high substrate concentrations when reaction time was elongated to several days. The structure of the product trisaccharide was defined as 1-fucosyllactose, where fucose is α-linked to the anomeric carbon of the β-glucose moiety of lactose. Furthermore, the enzyme was able to hydrolyze its own transfucosylation product and 2′-fucosyllactose but only poorly 3-fucosyllactose. As a conclusion, α-fucosidase from A. niger can transfucosylate lactose using free fucose as substrate producing a novel non-reducing 1-fucosyllactose.

scholarly journals Structural Characterization of Glucooligosaccharide Oxidase from Acremonium strictum

2005 ◽  
Vol 71 (12) ◽  
pp. 8881-8887 ◽  
Author(s):  
Meng-Hwan Lee ◽  
Wen-Lin Lai ◽  
Shuen-Fuh Lin ◽  
Cheng-Sheng Hsu ◽  
Shwu-Huey Liaw ◽  
...  
Keyword(s):  
Carbohydrate Binding ◽  
Kinetic Measurements ◽  
Acremonium Strictum ◽  
Potential Applications ◽  
Encoding Gene ◽  
Binding Groove ◽  
Cytokinin Dehydrogenase ◽  
Fad Binding ◽  
Binding Subsites

ABSTRACT Glucooligosaccharide oxidase from Acremonium strictum was screened for potential applications in oligosaccharide acid production and carbohydrate detection. This protein is a unique covalent flavoenzyme which catalyzes the oxidation of a variety of carbohydrates with high selectivity for cello- and maltooligosaccharides. Kinetic measurements suggested that this enzyme possesses an open carbohydrate-binding groove, which is mainly composed of two glucosyl-binding subsites. The encoding gene was subsequently cloned, and one intron was detected in the genomic DNA. Large amounts of active enzymes were expressed in Pichia pastoris, with a yield of 300 mg per liter medium. The protein was predicted to share structural homology with plant cytokinin dehydrogenase and related flavoproteins that share a conserved flavin adenine dinucleotide (FAD)-binding domain. The closest sequence matches are those of plant berberine bridge enzyme-like proteins, particularly the characteristic flavinylation site. Unexpectedly, mutation of the putative FAD-attaching residue, H70, to alanine, serine, cysteine, and tyrosine did not abolish the covalent FAD linkage and had little effect on the Km . Instead, the variants displayed k cat values that were 50- to 600-fold lower, indicating that H70 is crucial for efficient redox catalysis, perhaps through modulation of the oxidative power of the flavin.

Comparative study and characterization of starches isolated from unconventional tuber sources

2012 ◽  
Vol 32 (8-9) ◽  
pp. 531-537 ◽  
Author(s):  
Germán Ayala Valencia ◽  
Ana Cecilia Agudelo Henao ◽  
Rubén Antonio Vargas Zapata
Keyword(s):  
Proximate Analysis ◽  
Cassava Starch ◽  
Industrial Applications ◽  
Type Structure ◽  
Similar Degree ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Manihot Esculenta Crantz ◽  
Potential Applications

Abstract Some properties of canna (Canna indica L.) and bore (Alocasia macrorrhiza) starches were evaluated and compared using cassava starch (Manihot esculenta Crantz) as a reference. Proximate analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and viscosity measurements were performed. Canna and bore starches showed a similar degree of purity as that of the cassava starch. Canna starch exhibited higher thermal stability and viscosity of solution values than those of bore and cassava starches. XRD spectra showed that canna starch crystallizes as a B-type structure; however, bore and cassava starches crystallize as an A-type structure. Results proved that canna and bore starches are promising bio(materials), obtained from unconventional sources, to be used for industrial applications, as their physicochemical properties are similar to those of cassava starch, which it is known has potential applications in this area.

Synthesis and Characterization of D-Galactopyranose-Containing Amphiphilic Block Copolymers via ATRP

2010 ◽  
Vol 663-665 ◽  
pp. 1057-1060
Author(s):  
Xin Wang ◽  
Yuan Yuan Dou ◽  
Mei Shan Pei ◽  
Xin De Tang
Keyword(s):  
Self Assembly ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Monomethyl Ether ◽  
Amphiphilic Copolymers ◽  
Molecular Weights ◽  
Synthetic Materials ◽  
Potential Applications ◽  
Poly Ethylene

Biocompatible and biodegradable synthetic materials have attracted considerable attention during the past two decades. In this work, a series of amphiphilic triblock copolymers containing D-galactopyranose were synthesized by atom transfer radical polymerization (ATRP). The macroinitiator was prepared by the esterification between poly(ethylene glycol) monomethyl ether with a number-average molecular weight of 1200 g/mol (MeOPEO-1200) and 2-bromoisobutyryl bromide. The sugar-bearing monomer, 6-O-methacryloyl-1,2;3,4-di-O-isopropylidene-D-galactopyranose (MAIPG) was polymerized using PMDETA/CuBr as catalytic system and anisol as solvent. The chemical structure and composition of the resultant polymer MeOPEO-b-PMAIPG were verified by 1H NMR. The molecular weights and their polydispersities were characterized by gel permeation chromatography (GPC). The results indicate that the polymerization follows the mechanism of ATRP. The amphiphilic copolymers can self-assembly to from micelles with PMAIPG as the core and PEO as the corona, which have potential applications as biomaterials or controlled release drug delivery systems.

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