scholarly journals Biocatalytic Silylation: The Condensation of Phenols and Alcohols with Triethylsilanol

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 879
Author(s):  
Emily I. Sparkes ◽  
Chisom S. Egedeuzu ◽  
Billie Lias ◽  
Rehana Sung ◽  
Stephanie A. Caslin ◽  
...  
Keyword(s):  
Directed Evolution ◽  
Hydrolytic Enzyme ◽  
Marine Sponges ◽  
Aliphatic Alcohols ◽  
Future Application ◽  
Chiral Alcohols ◽  
Potential Candidate ◽  
Nonpolar Solvents ◽  
Substrate Conversion ◽  
Silicon Oxygen

Silicatein-α (Silα), a hydrolytic enzyme derived from siliceous marine sponges, is one of the few enzymes in nature capable of catalysing the metathesis of silicon–oxygen bonds. It is therefore of interest as a possible biocatalyst for the synthesis of organosiloxanes. To further investigate the substrate scope of this enzyme, a series of condensation reactions with a variety of phenols and aliphatic alcohols were carried out. In general, it was observed that Silα demonstrated a preference for phenols, though the conversions were relatively modest in most cases. In the two pairs of chiral alcohols that were investigated, it was found that the enzyme displayed a preference for the silylation of the S-enantiomers. Additionally, the enzyme’s tolerance to a range of solvents was tested. Silα had the highest level of substrate conversion in the nonpolar solvents n-octane and toluene, although the inclusion of up to 20% of 1,4-dioxane was tolerated. These results suggest that Silα is a potential candidate for directed evolution toward future application as a robust and selective biocatalyst for organosiloxane chemistry.

Application of quantum dots in drug delivery

2021 ◽  
Vol 11 ◽  
Author(s):  
Subham Jain N ◽  
Preeti S ◽  
Amit B Patil
Keyword(s):  
Drug Delivery ◽  
Quantum Dots ◽  
Organic Dyes ◽  
Quantum Confinement Effect ◽  
Semiconductor Nanocrystals ◽  
Drug Carriers ◽  
Research Field ◽  
The Body ◽  
Future Application ◽  
Potential Candidate

Background: The nanotechnology which has vast growth in the research field and the outcome product of nanotechnology is nanoparticles. Quantum dots with a size range of 2-10nm represents a new form in nanotechnology materials. It has showed widespread attention in recent years in the field of science and its application in drug delivery. Quantum dots are semiconductor nanocrystals which possess interesting properties and characteristics such as unique optical properties, quantum confinement effect and emit fluorescence on excitation with a light source which makes them a potential candidate for nano-probes and for carriers for biological application. Objective: The objective of the article is to explain the role and application of Quantum dots in drug delivery and its future application in pharmaceutical science and research. This review focuses on drug delivery through Quantum dots and Quantum dots helping nanocarriers for drug delivery. The development of QD nano-carriers for drugs has become a hotspot in the fields of nano-drug research. The Quantum Dot labelled nano-carrier can able to deliver the drugs with fewer side effects and it can able to trace the drug location in the body. Results: The Fluorescent emission of Quantum dots is better than other organic dyes which leads to better drug delivery for cancer or acting as a tag for other drug carriers. Conclusion: Because of emission property of Quantum Dots, it can be said used with other drug carriers and later it can be traced with the help of Quantum Dots. Quantum dots can be said as smart Drug delivery.

scholarly journals Comparative gene coexpression network analysis reveals different strategies of Trichoderma spp. associated with XYR1 and CRE1 during cellulose degradation

2020 ◽  
Author(s):  
Rafaela Rossi Rosolen ◽  
Alexandre Hild Aono ◽  
Déborah Aires Almeida ◽  
Jaire Alves Ferreira Filho ◽  
Maria Augusta Crivelente Horta ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cellulose Degradation ◽  
Phylogenetic Analyses ◽  
Hydrolytic Enzyme ◽  
Industrial Applications ◽  
Coexpression Network ◽  
Potential Candidate ◽  
Gene Coexpression Network ◽  
Trichoderma Spp ◽  
Gene Coexpression

AbstractTrichoderma atroviride and Trichoderma harzianum are mycoparasitic fungi widely used in agriculture as biocontrol agents. T. harzianum is also a potential candidate for hydrolytic enzyme production, in which gene expression is tightly controlled by the transcription factors (TFs) XYR1 and CRE1. Herein, we explore the genetic mechanisms of both regulators by inferring a gene coexpression network for T. harzianum (IOC-3844 and CBMAI-0179) and for T. atroviride (CBMAI-0020). The phylogenetic analyses indicated that XYR1 and CRE1 are extensively distributed among ascomycete fungi and suggested how T. atroviride is differentiated from T. harzianum. Transcripts encoding carbohydrate-active enzymes (CAZymes), TFs, sugar and ion transporters, and proteins with unknown function were coexpressed with xyr1 or cre1, and several metabolic pathways were recognized with high similarity between both regulators. Hubs from these groups included transcripts not yet characterized or described as related to cellulose degradation. The results differed according to the strains, suggesting that different molecular mechanisms related to XYR1 and CRE1 are used by Trichoderma spp. during cellulose degradation. These results can be exploited to improve the understanding of the regulation involved in hydrolytic enzyme expression, thereby expanding the potential of T. harzianum use in several industrial applications.

Preparation and Characterization of NiO/YSZ Cathode and BSCF/SDC Anode of SOEC for Hydrogen Production

2011 ◽  
Vol 287-290 ◽  
pp. 2494-2499 ◽  
Author(s):  
Bo Yu ◽  
Ming Fen Wen
Keyword(s):  
Hydrogen Production ◽  
Composite Powder ◽  
Combustion Method ◽  
Molar Ratio ◽  
Future Application ◽  
Electrochemical Performances ◽  
Potential Candidate ◽  
Temperature Application ◽  
Surface Morphologies

In this paper, NiO-YSZ composite powder was synthesized via in situ urea combustion method to prepare high homogeneity cathode. Sm0.2Ce0.8O1.9(SDC) is used as a barrier interlayer between Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) anode and 8YSZ electrolyte to avoid solid state interaction for high temperature application. The crystal structure and surface morphologies of NiO, YSZ, BSCF and SDC powders were characterized, respectively. The optimization of technological conditions for the synthesis was investigated. The adding amount was calculated by the combustion reaction equation. BSCF-SDC/YSZ/Ni-YSZ single button cells were prepared and the related electrochemical performances were test at 850°C. The research results showed that the products were well crystallized with NiO coating on YSZ particles. The optimized addition of CO(NH2)2to Ni(NO3)2was 2:1. A SOEC single cell made from NiO-YSZ with the molar ratio of 2:1 composite powder exhibited better performance than the other samples with the electrolytic voltage of 0.98V and showed excellent durability under the electrolytic currency of 0.33 A/cm2, the input stream of 90%H2O+10%H2. The hydrogen production rate of the single SOEC using BSCF/SDC can be up to 196.6 mL·cm-2h-1, which indicates that it could be a potential candidate for the future application of SOEC technology.

Recent Progress of Zn2SnO4-Based Dye Sensitized Solar Cells

2014 ◽  
Vol 809-810 ◽  
pp. 793-799
Author(s):  
D.T. Wang ◽  
G.S. Zhou ◽  
J.W. Li ◽  
Y.C. Dua ◽  
X.X. Zhang
Keyword(s):  
Solar Cells ◽  
Conversion Efficiency ◽  
Recent Progress ◽  
Low Cost ◽  
Dye Sensitized Solar Cells ◽  
High Energy ◽  
Future Application ◽  
Potential Candidate ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) have attracted extensive attention owning to their simple preparation prcess, low cost, and relatively high energy conversion efficiency. At present, most researches are focused on TiO2-based DSSC and high powder conversion efficiency of over 12.3% has been obtained. As a potential candidate, Zn2SnO4has drawn increasing attention for DSSCs due to its attractive electrical and optical properties (Eg = 3.6 eV, electron mobility of 10–15 cm2V-1s-1). In this article, we maily reviewed the recent progress of Zn2SnO4-based DSSCs and put forward ideas for designing new Zn2SnO4materials in future application for DSSCs.

scholarly journals Engineering of Phenylacetaldehyde Reductase for Efficient Substrate Conversion in Concentrated 2-Propanol

2005 ◽  
Vol 71 (8) ◽  
pp. 4713-4720 ◽  
Author(s):  
Yoshihide Makino ◽  
Kousuke Inoue ◽  
Tohru Dairi ◽  
Nobuya Itoh
Keyword(s):  
Conversion Efficiency ◽  
Cofactor Regeneration ◽  
Hydrogen Donor ◽  
Chiral Alcohols ◽  
Mutant Library ◽  
Aryl Ketones ◽  
Substrate Conversion ◽  
High Concentrations ◽  
Selection Of

ABSTRACT Phenylacetaldehyde reductase (PAR) is suitable for the conversion of various aryl ketones and 2-alkanones to corresponding chiral alcohols. 2-Propanol acts as a substrate solvent and hydrogen donor of coupled cofactor regeneration during the conversion of substrates catalyzed by PAR. To improve the conversion efficiency in high concentrations of substrate and 2-propanol, selection of a PAR mutant library and the subsequent rearrangement of mutations were attempted. With only a single selection round and following the manual combination of advantageous mutations, PAR was successfully adapted for the conversion of high concentrations of substrate with concentrated 2-propanol. This method will be widely applicable for the engineering of enzymes potentially valuable for industry.

Novel pectinase from Piriformospora indica, optimization of growth parameters and enzyme production in submerged culture condition

2018 ◽  
Vol 43 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Mohammad Heidarizadeh ◽  
Parisa Fathi Rezaei ◽  
Saleh Shahabivand
Keyword(s):  
Growth Parameters ◽  
Growth Yield ◽  
Piriformospora Indica ◽  
Future Application ◽  
Total Protein Content ◽  
Potential Candidate ◽  
Dry Cell Weight ◽  
Optimum Ph ◽  
Pectinase Activity ◽  
Pectinase Production

AbstractBackground:Pectinases are one of the upcoming enzymes in food processing industries and they hydrolyze pectin substances.Objectives:This study was done to examine the production of pectinase byPiriformospora indicain submerged fermentation (SmF) along with growth parameters.Materials and methods:The fungusP. indicawas cultured on Kafer medium supplemented with pectin for 0–12 days and fungus growth, number of spores, total protein content, and pectinase activity were investigated.Results:Firstly, pectinase secretion byP. indicawas confirmed by cup-plate assay. The maximum dry cell weight (10.21 g/L), growth yield (0.65 g/g), specific growth rate (0.56 day−1) and pectinase activity (10.47 U/mL) on pectin containing medium (P+) were achieved after 6 day of culture. In the case of pectin free medium (P−) all the parameters were less than P+medium. The pectinase production byP. indicaon P+was 2.7 times higher than P−. The optimum pH and temperature for maximum polygalacturonase activity were 5 and 50°C, respectively.Conclusions:For the first time, the work confirmed pectinase secretion byP. indicafungus and it could be a good source for pectinase production. Moreover, optimum pH 5, make it a potential candidate for future application in fruit juice industries.

scholarly journals IDENTIFICATION AND PARTIAL CHARACTERIZATION OF CRUDE EXTRACELLULAR ENZYMES FROM BACTERIA ISOLATED FROM SHRIMP WASTE PROCESSING

2013 ◽  
Vol 7 (1) ◽  
pp. 11 ◽  
Author(s):  
Ekowati Chasanah ◽  
Mahrus Ali ◽  
Miftahul Ilmi
Keyword(s):  
Hydrolytic Enzyme ◽  
Value Added ◽  
Biologically Active ◽  
Future Application ◽  
Chloride Salt ◽  
Shrimp Waste ◽  
Chitinolytic Enzyme ◽  
Degrading Enzymes ◽  
Chitosan Oligomer

Attention on chitin degrading enzymes has been growing since their ability to reduce the waste of shrimp/other crustaceans processing industries and converting them into value added products such as biologically active chitin and chitosan oligomer. Previous experiment found that KLU 11.16 isolate was one of the potential bacteria isolated from shrimp waste producing chitinolytic enzymes including chitosanases. A study on the identification of KLU 11.16 extracellularcrude enzyme was carried out by cultivating the bacteria on chitin medium. Due to the wide application of chitosanase, the characterization of the crude chitosanase was carried out after an identification of the enzymes secreted. Based on assessment using zymogram technique, this bacteria secreted a mixed extracellular chitinolytic enzyme and other hydrolytic enzyme. The crudechitinolytic enzyme degraded 85% deacetylated (DA) better than 100% DA chitosan, and slightly degraded glycol chitin, indicating that KLU 11.16 secreted chitosanases and chitinases enzyme. In addition to the chitinolytic enzyme, the bacteria also secreted protein and carbohydrate degrading enzymes when running at SDS-PAGE enriched with casein, soluble starch and CMC substrates.Crude chitosanases enzyme was performed well at pH 6 and temperature of 300C, and the activity can be increased by addition of 1 mM Fe 2+ in form of chloride salt. Addition of detergent, i.e1mM of Triton X-100 and SDS slightly decreased the activity. Future application of the crude chitosanase from KLU 11.16 was on producing chitosan derivative such as chitosan oligomer using substrateof 85% DA chitosan, which is more digestable by other enzymes secreted by KLU 11.16

scholarly journals Directed Evolution of an Efficient and Thermostable PET Depolymerase

2021 ◽  
Author(s):  
Elizabeth Bell ◽  
Ross Smithson ◽  
Siobhan Kilbride ◽  
Jake Foster ◽  
Florence Hardy ◽  
...  
Keyword(s):  
Directed Evolution ◽  
Elevated Temperatures ◽  
Hydrolytic Enzyme ◽  
Catalytic Performance ◽  
Structural Characterisation ◽  
Plastic Recycling ◽  
Degrading Enzymes ◽  
Poly Ethylene Terephthalate ◽  
Primary Selection ◽  
Poly Ethylene

The recent discovery of a hydrolytic enzyme, IsPETase, that can deconstruct poly(ethylene) terephthalate (PET), has sparked great interest in biocatalytic approaches to recycle plastics. Realisation of commercial utility will require the development of robust engineered enzymes that meet the demands of industrial processes. Although rationally engineered variants of PETases have been reported, enzymes that have been experimentally optimised through iterative rounds of directed evolution - the go-to method for engineering industrially useful biocatalysts – have not yet been described. Here, we report the development and implementation of an automated, high-throughput directed evolution platform for engineering polymer degrading enzymes. Evaluation of >13,000 IsPETase variants, applying catalytic activity at elevated temperatures as a primary selection pressure, afforded a HotPETase variant with 21 mutations that has a melting temperature of 82.5C and can therefore operate near or above the glass transition temperature of PET (60-70C). HotPETase can depolymerise semi-crystalline PET more rapidly than previously reported PETases and can selectively deconstruct the PET component of a laminated packaging multi-material. Structural characterisation of HotPETase reveals several interesting features that have emerged during evolution to improve thermotolerance and catalytic performance. Our study establishes laboratory evolution as a platform to engineer useful plastic degrading enzymes to underpin biocatalytic plastic recycling processes.

Conditions for atomic imaging of mullite

1989 ◽  
Vol 47 ◽  
pp. 418-419
Author(s):  
T. A. Epicier ◽  
G. Thomas
Keyword(s):  
Oxygen Vacancies ◽  
High Resolution Electron Microscopy ◽  
Ceramic Materials ◽  
Work Conditions ◽  
Real Space ◽  
Potential Candidate ◽  
Silicate Mineral ◽  
Resolution Electron ◽  
The Subject ◽  
Aluminium Silicate

Mullite is an aluminium-silicate mineral of current interest since it is a potential candidate for high temperature applications in the ceramic materials field.In the present work, conditions under which the structure of mullite can be optimally imaged by means of High Resolution Electron Microscopy (HREM) have been investigated. Special reference is made to the Atomic Resolution Microscope at Berkeley which allows real space information up to ≈ 0.17 nm to be directly transferred; numerous multislice calculations (conducted with the CEMPAS programs) as well as extensive experimental through-focus series taken from a commercial “3:2” mullite at 800 kV clearly show that a resolution of at least 0.19 nm is required if one wants to get a straightforward confirmation of atomic models of mullite, which is known to undergo non-stoichiometry associated with the presence of oxygen vacancies.Indeed the composition of mullite ranges from approximatively 3Al2O3-2SiO2 (referred here as 3:2-mullite) to 2Al2O3-1SiO2, and its structure is still the subject of refinements (see, for example, refs. 4, 5, 6).

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