Wyniki wyszukiwania dla: STRAINS
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A new hyperbolic-polynomial higher-order elasticity theory for mechanics of thick FGM beams with imperfection in the material composition
PublikacjaA drawback to the material composition of thick functionally graded materials (FGM) beams is checked out in this research in conjunction with a novel hyperbolic‐polynomial higher‐order elasticity beam theory (HPET). The proposed beam model consists of a novel shape function for the distribution of shear stress deformation in the transverse coordinate. The beam theory also incorporates the stretching effect to present an indirect...
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Antifungal Activity of Capridine β as a Consequence of Its Biotransformation into Metabolite Affecting Yeast Topoisomerase II Activity
PublikacjaIn the last few years,increasing importance is attached to problems caused by fungal pathogens. Current methods of preventing fungal infections remain unsatisfactory. There are several antifungal compounds whichare highly effective in some cases, however, they have limitations in usage: Nephrotoxicity and other adverse effects. In addition, the frequent use of available fungistatic drugs promotes drug resistance....
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Comprehensive Evaluation of the Biological Properties of Surface-Modified Titanium Alloy Implants
PublikacjaAn increasing interest in the fabrication of implants made of titanium and its alloys results from their capacity to be integrated into the bone system. This integration is facilitated by different modifications of the implant surface. Here, we assessed the bioactivity of amorphous titania nanoporous and nanotubular coatings (TNTs), produced by electrochemical oxidation of Ti6Al4V orthopedic implants’ surface. The chemical composition...
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Comparative Study of the Mechanical Behaviour of Bitumen- and Cement-Dominated Mixtures with Reclaimed Asphalt
PublikacjaThe bitumen emulsion-based recycling is a commonly used maintenance treatment in the rehabilitation of low-and medium-volume roads in Europe. Nevertheless, the wide range of climatic conditions across the continent resulted in the variety of mixture concepts and the requirements being adopted for various local conditions. In this regard, the most commonly used parameter to distinguish between the main mixture concepts is bitumen...
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A New Expression System Based on Psychrotolerant Debaryomyces macquariensis Yeast and Its Application to the Production of Cold-Active β-D-Galactosidase from Paracoccus sp. 32d
PublikacjaYeasts provide attractive host/vector systems for heterologous gene expression. The currently used yeast-based expression platforms include mesophilic and thermotolerant species. A eukaryotic expression system working at low temperatures could be particularly useful for the production of thermolabile proteins and proteins that tend to form insoluble aggregates. For this purpose, an expression system based on an Antarctic psychrotolerant...
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Józef Kur prof. dr hab.
Osoby -
Analysis of Residual Stresses and Dislocation Density of AA6082 Butt Welds Produced by Friction Sir Welding
PublikacjaThe Friction Stir Welding (FSW) method was employed to join AA6082 sheets. The welds were produced with different tool traverse speed (200 and 250 mm/min), rotational speed (1000 and 1250 RPM) and tool tilt angle (0 and 2 deg). Based on the analysis of XRD patterns, the total precipitation volume fractions in the nugget zones and the base material were calculated. The FSW process resulted in a reduction in the fraction of precipitates...
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Correlation between the number of Pro-Ala repeats in the EmrA homologue of Acinetobacter baumannii and resistance to netilmicin, tobramycin, imipenem and ceftazidime
PublikacjaAcinetobacter baumannii coccobacilli are dangerous to patients in intensive care units because of their multidrug resistance to antibiotics, developed mainly in the past decade. This study aimed to examine whether there is a significant correlation between the number of Pro-Ala repeats in the CAP01997 protein, the EmrA homologue of A. baumannii, and resistance to antibiotics. A total of 79 multidrug-resistant A. baumannii strains...
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Calculations of notch stress factor of a thin-walled spreader bracket fillet weld with the use of a local stress approach
PublikacjaPresence of geometric notches in welded joints causes concentration of strains and stresses, therefore reducing fatigue strength of such joints. This article presents an analysis of stress concentrations in a fillet weld of a spreader mounting bracket on a small sailing yacht. The aim of this article is to direct the attention of designers, manufacturers and regulatory bodies to issues of fatigue cracks that form in brackets fastening...
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Evaluation of possibilities of genotyping of Candida glabrata clinical isolates with RAPD-PCR method and microsatellite analysis
PublikacjaThe aim of the study was to compare the discriminatory power of RAPD-PCR method using RSD10 primer and microsatellite (GACA)4 analysis for genotyping clinical isolates of C. glabrata. Isolates were received from patients of two Polish hospitals: Children's Memorial Health Institute in Warsaw (n=17) and Medical University of Gdansk (n=37). Species identification was confirmed by two phenotypic methods: growth on chromagar plates...
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The New LM-PCR/Shifter Method for the Genotyping of Microorganism
PublikacjaTechniques relies on the ligation of appropriates adapters (LM-PCR) as AFLP, PCR MP and ADSRRS are successfully used for epidemiological studies for prokaryotic and eukaryotic microorganisms. In this study we propose a new method, called the LM-PCR/Shifter, based on the use of a Class IIS restriction enzyme giving restriction fragments with different 4 base 5' overhangs (Shifter) and the ligation of appropriate oligonucleotide...
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Temperature influences on shear stability of a nanosize plate with piezoelectricity effect
PublikacjaPurpose The purpose of this paper is to predict the mechanical behavior of a piezoelectric nanoplate under shear stability by taking electric voltage into account in thermal environment. Design/methodology/approach Simplified first-order shear deformation theory has been used as a displacement field. Modified couple stress theory has been applied for considering small-size effects. An analytical solution has been taken into account...
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A Novel Cryptic Clostridial Peptide That Kills Bacteria by a Cell Membrane Permeabilization Mechanism
PublikacjaThis work reports detailed characteristics of the antimicrobial peptide Intestinalin (P30), which is derived from the LysC enzyme of Clostridium intestinale strain URNW. The peptide shows a broader antibacterial spectrum than the parental enzyme, showing potent antimicrobial activity against clinical strains of Gram-positive staphylococci and Gram-negative pathogens and causing between 3.04 ± 0.12 log kill for Pseudomonas aeruginosa...
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Electrochemically Obtained TiO2/CuxOy Nanotube Arrays Presenting a Photocatalytic Response in Processes of Pollutants Degradation and Bacteria Inactivation in Aqueous Phase
PublikacjaTiO2/CuxOy nanotube (NT) arrays were synthesized using the anodization method in the presence of ethylene glycol and different parameters applied. The presence, morphology, and chemical character of the obtained structures was characterized using a variety of methods—SEM (scanning electron microscopy), XPS (X-ray photoelectron spectroscopy), XRD (X-ray crystallography), PL (photoluminescence), and EDX (energy-dispersive X-ray spectroscopy)....
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Cloning, expression, and biochemical characterization of a coldactive GDSL-esterase of a Pseudomonas sp. S9 isolated from Spitsbergen island soil
PublikacjaAn estS9 gene, encoding an esterase of the psychrotolerant bacterium Pseudomonas sp. S9 was cloned and sequenced. The deduced sequence revealed a protein of 636 amino acid residues with a molecular mass of 69 kDa.Further amino acid sequence analysis revealed that the EstS9 enzyme contained a G-D-S-L motif centered at a catalytic serine, an N-terminal catalytic domain and a C-terminal autotransporter domain. Two recombinant E. coli...
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Encapsulation of Amikacin into Microparticles Based on Low-Molecular-Weight Poly(lactic acid) and Poly(lactic acid-co-polyethylene glycol)
PublikacjaThe aim of this study was to fabricate novel microparticles (MPs) for efficient and long-term delivery of amikacin (AMI). The emulsification method proposed for encapsulating AMI employed low-molecular-weight poly(lactic acid) (PLA) and poly(lactic acid-co-polyethylene glycol) (PLA−PEG), both supplemented with poly(vinyl alcohol) (PVA). The diameters of the particles obtained were determined as less than 30 μm. Based on an in-vitro...
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Nonlinear Free and Forced Vibrations of a Hyperelastic Micro/Nanobeam Considering Strain Stiffening Effect
PublikacjaIn recent years, the static and dynamic response of micro/nanobeams made of hyperelasticity materials received great attention. In the majority of studies in this area, the strain-stiffing effect that plays a major role in many hyperelastic materials has not been investigated deeply. Moreover, the influence of the size effect and large rotation for such a beam that is important for the large deformation was not addressed. This...
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Discrimination of hospital isolates of Acinetobacter baumannii using repeated sequences and whole genome alignment differential analysis
PublikacjaAn optimized method for bacterial strain differentiation, based on combination of Repeated Sequences and Whole Genome Alignment Differential Analysis (RS&WGADA), is presented in this report. In this analysis, 51 Acinetobacter baumannii multidrug-resistance strains from one hospital environment and patients from 14 hospital wards were classified on the basis of polymorphisms of repeated sequences located in CRISPR region, variation...
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On mechanics of piezocomposite shell structures
PublikacjaThis study presents an original and novel investigation into the mechanics of piezo-flexo-magneto-elastic nanocomposite doubly-curved shells (PFMDCSs) and the ability to detect the lower and higher levels of electro-magnetic fields. In this context, by utilizing the first-order shear deformation shell model, stresses and strains are acquired. By imposing Hamilton's principle and the von Kármán approach, the governing equations...
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Multiple transcriptional factors regulate transcription of the rpoE gene in Escherichia coli under different growth conditions and when the lipopolysaccharide biosynthesis is defective.
PublikacjaThe RpoE sigma factor is essential for the viability of Escherichia coli. RpoE regulates extracytoplasmic functions including lipopolysaccharide (LPS) translocation and some of its non-stoichiometric modifications. Transcription of the rpoE gene is positively autoregulated by EσE and by unknown mechanisms that control the expression of its distally located promoter(s). Mapping of 5′ ends of rpoE mRNA identified five new transcriptional...
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Estimation of Stresses in a Dry Sand Layer Tested on Shaking Table
PublikacjaTheoretical analysis of shaking table experiments, simulating earthquake response of a dry sand layer, is presented. The aim of such experiments is to study seismic-induced compaction of soil and resulting settlements. In order to determine the soil compaction, the cyclic stresses and strains should be calculated first. These stresses are caused by the cyclic horizontal acceleration at the base of soil layer, so it is important...
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Essential Oils, Silver Nanoparticles and Propolis as Alternative Agents Against Fluconazole Resistant Candida albicans, Candida glabrata and Candida krusei Clinical Isolates
PublikacjaDevelopment of effective and safe therapeutic treatment of fungal infections remains one of the major challenge for modern medicine. The aim of presented investigation was to analyze the in vitro antifungal activity of selected essential oils, ethanolic extracts of propolis and silver nanoparticles dropped on TiO2 against azole-resistant C. albicans (n = 20), C. glabrata (n = 14) and C. krusei (n = 10) clinical isolates. Among...
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Characterization of recombinant homocitrate synthase from Candida albicans
PublikacjaLYS21 and LYS22 genes from Candida albicans encoding isoforms of homocitrate synthase (HCS), an enzyme catalyzing the first committed step in the L-lysine biosynthetic pathway, were cloned and expressed as NoligoHistagged fusion proteins in Escherichia coli. The purified gene products revealed HCS activity, i.e. catalyzed the condensation of α-ketoglutarate with acetyl-coenzyme A to yield homocitrate. The recombinant enzymes were purified...
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Chemical and biological characterization of Ocimum basilicum L. phenolic extract and essential oil derived through ultrasound and microwave-assisted extraction techniques
PublikacjaPlant-derived bioactive molecules are increasingly utilized in food processing as natural additives, driven by a growing interest in healthier lifestyles. This trend has spurred industries to reformulate products to meet the demands of health-conscious consumers. This study investigates the phenolic extract and essential oil of O. basilicum L. obtained via ultrasound-assisted extraction and microwave-assisted extraction, respectively. Characterization...
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The selective salinity and hydrazine parameters for the start-up of non-anammox-specific biomass SBR
PublikacjaThe presence of ammonium (NH 4+ ) in wastewater above the permissible limits leads to undesirable ecological impact and public health concerns. In this study, the anaerobic ammonium oxidizing (anammox) bacteria-mediated nitrogen removal was investigated using a sequential batch reactor (SBR). Effects of different salinity levels were evaluated on the bacterial activity at: mild (below 0.2 g NaCl/L), elevated (18.2 g NaCl/L) and...
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Phytoplankton communities of polar regions–Diversity depending on environmental conditions and chemical anthropopressure
PublikacjaThe polar regions (Arctic and Antarctic) constitute up to 14% of the biosphere and offer some of the coldest and most arid Earth's environments. Nevertheless several oxygenic phototrophs including some higher plants, mosses, lichens, various algal groups and cyanobacteria, survive that harsh climate and create the base of the trophic relationships in fragile ecosystems of polar environments. Ecosystems in polar regions are characterized...
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Molecular Dynamics simulations of thermal conductivity of penta-graphene
PublikacjaThe thermal conductivity of penta-graphene (PG), a new two dimensional carbon allotrope and its dependence on temperature, strain, and direction are studied in this paper. The thermal conductivity of PG is investigated using a non-equilibrium molecular dynamics simulation (NEMD) with the Two Region Method by applying the optimized Tersoff interatomic potential. Our study shows that the thermal conductivity of PG (determined for...
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Human-associated bacteria and their mobile genetic elements - important minority in wastewater and wastewater impacted ecosystems
PublikacjaSince human-associated bacteria have been recognized as vectors in two - way gene transmission between the pathogenic and environmental populations, health hazard connected with wastewater discharge requires reevaluation. In this paper the particular attention was given to antimicrobial-resistance of Escherichia coli and enterococci isolated from wastewater and wastewater impacted environments. The obtained results showed that...
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Molecular basis of lipopolysaccharide heterogeneity in Escherichia coli: envelope stress-responsive regulators control the incorporation of glycoforms with a third 3-deoxy-α-D-manno-oct-2-ulosonic acid and rhamnose.
PublikacjaMass spectrometric analyses of lipopolysaccharide (LPS) from isogenic Escherichia coli strains with nonpolar mutations in the waa locus or overexpression of their cognate genes revealed that waaZ and waaS are the structural genes required for the incorporation of the third 3-deoxy-α-D-manno-oct-2-ulosonic acid (Kdo) linked to Kdo disaccharide and rhamnose, respectively. The incorporation of rhamnose requires prior sequential incorporation...
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Genotyping Techniques for Determining the Diversity of Microorganisms
PublikacjaTyping of microbial pathogens, or identifying bacteria at the strain level, is particularly important for diagnosis, treatment, and epidemiological surveillance of bacterial infections. This is especially the case for bacteria exhibiting high levels of antibiotic resistance or virulence, and those involved in nosocomial or pandemic infections. Strain typing also has applications in studying bacterial population dynamics. The part...
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Drug-Eluting Biopsy Needle as a Novel Strategy for Antimicrobial Prophylaxis in Transrectal Prostate Biopsy
PublikacjaOBJECTIVES: To preclinically evaluate drug-eluting biopsy needles (patent pending WO2016118026) as a new potential way of antimicrobial prophylaxis for transrectal prostate biopsy. METHODS: Twenty steel biopsy needles have been coated with polyvinyl alcohol, ciprofloxacin, and amikacin. Modified biopsy needles have been randomly divided into 3 groups (1:2:1 ratio). Needles from group I were immersed for 30 minutes in dedicated...
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A new 1-nitro-9-aminoacridine derivative targeting yeast topoisomerase II able to overcome fluconazole-resistance
PublikacjaFungal resistance remains a significant threat and a leading cause of death worldwide. Thus, overcoming microbial infections have again become a serious clinical problem. Although acridine derivatives are widely analyzed as anticancer agents, only a few reports have demonstrated their antifungal activity. In an effort to develop biologically active antifungals, twelve novel C-857 (9-(2′ -hydroxyethylamino)-1-nitroacridine) and...
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Antimicrobial resistance of fecal indicators in muncipal wastewater treatment plant
PublikacjaAntimicrobial resistance of fecal coliforms (n = 153) and enterococci (n = 199) isolates was investigated in municipal wastewater treatment plant (WWTP) based on activated sludge system. The number of fecal indicators (in influent and effluent as well as in the aeration chamber and in return activated sludge mixture) was determined using selective media. Susceptibility of selected strains was tested against 19 (aminoglycosides,...
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Structural phase transitions in multicomponent La0.2Nd0.2Sm0.2Gd0.2RE50.2NbO4 (RE5 = Ho, Y, Tb, Eu, Pr) oxides
PublikacjaIn this work, the influence of compositional complexity on the structural and thermal properties of multicomponent rare-earth ortho-niobates from the La0.2Nd0.2Sm0.2Gd0.2RE50.2NbO4 (RE5 = Ho, Y, Tb, Eu, Pr) series have been investigated. Based on X-ray powder diffraction studies using synchrotron radiation, it was found that all tested materials were pure single-phase compositions and showed stability in the monoclinic I2/c crystal...
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Evaluation of antimicrobial activity of porous composites based on chitosan/poly (vinyl alcohol)
Dane BadawczeThe dataset contains the results of microbiological tests of composite porous materials whose activity was assessed for their ability to reduce the number of Escherichia coli and Staphylococcus aureus strain, representing the Gram (-) and Gram (+) bacteria, respectively.
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Anthra[1,2-d][1,2,3]triazine-4,7,12(3H)-triones as a New Class of Antistaphylococcal Agents: Synthesis and Biological Evaluation
PublikacjaThe development and spread of resistance of human pathogenic bacteria to the action of commonly used antibacterial drugs is one of the key problems in modern medicine. One of the especially dangerous and easily developing antibiotic resistant bacterial species is Staphylococcus aureus. Anthra[1,2-d][1,2,3]triazine-4,7,12(3H)-triones 22–38 have been developed as novel effective antistaphylococcal agents. These compounds have been...
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Regulation of LPS assembly via controlled proteolysis and sensing of LPS stress in Escherichia coli
PublikacjaLipopolysaccharide (LPS) is a complex glycolipid, essential for the bacterial viability and along with phospholipids, it constitutes the major amphiphilic component of outer membrane (OM) in most of the Gram-negative bacteria, including Escherichia coli. LPS molecules confer an effective permeability barrier to the OM and play a crucial role in bacteria-environment and -host interactions. The synthesis and accumulation of this...
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Pilicides effectively hinder chaperone-usher interactions in all Gram-negative bacteria
PublikacjaThe chaperone-usher pathway of adhesive structures biogenesis is highly conserved in all Gram-negative bacteria. Pili are polymers of thousands protein subunits that possess conserved immunoglobuline-like structure denoted by lack of the seventh G strand. The effect of this structural defect is a hydrophobic acceptor cleft. The folding of protein subunits is strictly dependent on the action of specific periplasmic chaperone protein...
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Peptide Permeases in Candida albicans
PublikacjaAims: The aim of this work was to characterize oligopeptide uptake in Candida albicans mutants in which the genes encoding putative peptide permeases were selectively disrupted. Initial velocities of transport of model oligopeptides, (Ala)2, (Ala)3, (Ala)4, and sensitivity of mutants to antifungal oligopeptides containing N3-(4-methoxyfumaroyl)-L-2,3-diaminopropanoic acid (FMDP) were determined and compared to those of the wild-type...
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Composition and antimicrobial activity of fatty acids detected in the hygroscopic secretion collected from the secretory setae of larvae of the biting midge Forcipomyia nigra (Diptera: Ceratopogonidae)
PublikacjaThe hygroscopic secretion produced by the secretory setae of terrestrial larvae of the biting midge Forcipomyia nigra (Winnertz) was analysed using gas chromatography coupled with mass spectrometry (GC-MS). The viscous secretion is stored at the top of each seta and absorbs water from moist air. GC-MS analyses (four independent tests) showed that the secretion contained 12 free fatty acids, the most abundant of which were oleic...
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Typing of Scopulariopsis and Microascus fungi by Random Amplified Polymorphic DNA (RAPD)
PublikacjaOBJECTIVES Scopulariopsis species and their teleomorphs of the genus Microascus are commonly isolated from soil, decaying plant material and indoor environments. Moreover, certain Scopulariopsis and Microascus species are recognised as opportunistic human pathogens. Although most species can be identified by detailed morphological study, phenotypic characters appear to overlap in several cases and morphology seems to be insufficient...
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Sequence variants of p21 gene of the MRL/MpJ mouse: a possible association with the deficit of p21 protein and regenerative phenotype.
PublikacjaThe MRL/MpJ mouse is known for its enhanced regeneration abilities that manifested themselves by scarless ear-hole wound closure. The deficit of p21 found in the MRL is associated with the regenerative capacity as the p21 gene knockout in a mouse strain unrelated to the MRL mouse results in an ear-hole closure effect, similar to that observed in the MRL mouse. Cdkn1a gene encodes p21 protein, a cyclin-dependent kinase inhibitor,...
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Inter Applied Chemistry Programme 6 A practical approach to novel industrial enzymes Dr Natasha Bozic
Kursy OnlineInter Applied Chemistry Programme 6 - A practical approach to novel industrial enzymes Dr Natasha Bozic The purpose of the course is to introduce students to the technologies of industrial enzymes discovery and manufacturing and to provide in depth insight about the advantages of using enzyme preparations in industry. Lectures will cover the common workflows of industrial enzymology including following topics: general enzyme...