310 research outputs found

    New enzyme based process direction to prevent wool shrinking without substantial tensile strength loss

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    In this paper a new enzymatic process direction is described for obtaining machine washable wool with acceptable quality. In general, application of protease enzyme technology in wool processing results in considerable loss of tensile strength by diffusion of the enzyme into the interior of wool fibers. To overcome this disadvantage enzymatic activity has been more targeted to the outer surface of the scales by improving the susceptibility of the outer surface scale protein for proteolytic degradation. This has been realized by a pretreatment of wool with hydrogen peroxide at alkaline pH in the presence of high concentrations of salt

    Purification and mechanistic characterisation of two polygalacturonases from Sclerotium rolfsii

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    Sclerotium rolfsii (strain CBS 350.80) was found to produce extraordinary high amounts of polygalacturonases (PGs). Two of these extracellular enzymes were purified by a recently introduced preparative electrophoretic device (isoelectric focusing mode of free flow electrophoresis). PG 1 (39.5 kDa, pI 6.5) and PG 2 (38 kDa, pI 5.4) exhibited quite similar properties, they were found to be both endo-acting enzymes. Both PGs cleaved penta- and trigalacturonic acid while tetragalacturonic acid was only cleaved when trigalacturonic acid was present. The latter substrate was hydrolysed much faster by PG 2. Both enzymes were active on pectins with different degrees of esterification, they were sensitive towards Ca-cations and not glycosylated. The kinetic properties were measured by viscosimetry with polygalacturonic acid as a substrate. NMR experiments on a model substrate revealed an inverting mechanism of carbohydrate hydrolysis for both enzymes

    Thermo-alkali-stable catalases from newly isolated Bacillus sp. for the treatment and recycling of textile bleaching effluents

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    Three thermoalkaliphilic bacteria, which were grown at pH 9.3–10 and 60–65 °C were isolated out of a textile wastewater drain. The unknown micro-organisms were identified as thermoalkaliphilic Bacillus sp. Growth nditions were studied and catalase activities and stabilities compared. Catalases from Bacillus SF showed high stabilities at 60 °C and pH 9 (t1/2=38 h) and thus this strain was chosen for further investigations, such as electron microscopy, immobilization of catalase and hydrogen peroxide degradation studies. Degradation of hydrogen peroxide with an immobilized catalase from Bacillus SF enabled the reuse of the water for the dyeing process. In contrast, application of the free enzyme for treatment of bleaching effluents, caused interaction between the denaturated protein and the dye, resulting in reduced dye uptake, and a higher color difference of 1.3 ΔE* of dyed fabrics compared to 0.9 ΔE* when using the immobilized enzyme

    Desfechos psicolĂłgicos em longo prazo apĂłs alta da terapia intensiva

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    Objective: To investigate the longterm psychological outcome in survivors of critical illness after intensive care unit discharge. Methods: A prospective cohort of survivors admitted to a mixed intensive care unit between January and September 2010 was evaluated six months and five years after hospital discharge. The Dementia Rating Scale-2, the Hospital Anxiety and Depression Scale, the Posttraumatic stress syndrome 14-questions inventory, the Euro Quality of Life 5 Dimensions (EQ-5-D), and the Visual Analogue Scale (EQ VAS) were assessed at both follow-up periods. Results: Of 267 patients, 25 patients were evaluated at 6 months after discharge (62 ± 16 years); 12 (48%) presented cognitive impairment, 6 (24%) anxiety, 4 (16%) depression, and 4 (16%) post-traumatic stress disorder. Among those re-evaluated five years after discharge (n = 17; 65 ± 15 years), the frequency of cognitive impairment dropped from 8 (47%) to 3 (18%) (p = 0.063), due to improvement in these patients over time, and other patients did not acquire any dysfunction after discharge. At five years after discharge, only two patients (12%) reported anxiety, and none had depression or post-traumatic stress disorder. No differences were found between the six-month and five-year follow-ups regarding EQ-5-D and EQ VAS. Conclusion: Survivors do not show a progressive decline in cognitive function or quality of life within five years after intensive care unit discharge. Psychopathological symptoms tend to decrease with time.Objetivo: Investigar o desfecho psicolĂłgico em longo prazo em sobreviventes de doenças crĂ­ticas, apĂłs alta da unidade de terapia intensiva. MĂ©todos: Avaliou-se coorte prospectiva de pacientes sobreviventes apĂłs admissĂŁo a uma unidade de terapia intensiva mista entre janeiro e setembro de 2010, 6 meses e 5 anos apĂłs a alta hospitalar. Aplicaram-se em todos os momentos as seguintes escalas: Dementia Rating Scale-2, Hospital Anxiety and Depression Scale, Post-Traumatic Stress Syndrome 14-Questions Inventory, Euro Quality of Life 5 Dimensions (EQ-5-D) e Visual Analogue Scale (EQ VAS). Resultados: Dentre 267 pacientes, 25 foram avaliados apĂłs 6 meses (idade: 62 ± 16 anos). Aos 6 meses, 48% apresentavam comprometimento cognitivo; 24% ansiedade, 16% depressĂŁo e 16% transtorno de estresse pĂłs-traumĂĄtico. Foram reavaliados 5 anos apĂłs a alta 17 pacientes, com idade: 65 ± 15 anos. Dentre eles, a frequĂȘncia de comprometimento cognitivo caiu de 47% para 18% (p = 0,063), em razĂŁo da melhora destes pacientes ao longo do tempo e do nĂŁo surgimento desta condição em outros pacientes apĂłs a alta. Ainda apĂłs 5 anos, apenas 12% da amostra relatou ansiedade, e nenhum tinha depressĂŁo ou transtorno de estresse pĂłs-traumĂĄtico. NĂŁo se encontraram diferenças em termos das escalas EQ-5-D e EQ VAS entre as avaliaçÔes apĂłs 6 meses e 5 anos. ConclusĂŁo: Os sobreviventes nĂŁo apresentaram declĂ­nio progressivo da função cognitiva ou da qualidade de vida dentro de 5 anos apĂłs a alta da unidade de terapia intensiva. Os sintomas psicopatolĂłgicos tenderam a diminuir com o tempo.info:eu-repo/semantics/publishedVersio

    Antimicrobials in animal agriculture: Parables and policy

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    In addition to the scientific, economic, regulatory and other policy factors that impact on antimicrobial decision-making in different jurisdictions around the world, there exist ethical, social and cultural bases for the contemporary use of these products in animal agriculture. Thus, the use of the word ‘parable’ to describe the contemporary moral stories that help to guide ethical antimicrobial use practices and broader policy decisions in animal agriculture is appropriate. Several of these stories reflect difficult decisions that arise from conflicting moral imperatives (i.e. both towards animal welfare and towards human health). Understanding the factors that combine to define the past and present paradigms of antimicrobial usage is crucial to mapping a path forward. There exist barriers, as well as opportunities, for advancing scenarios for reducing antimicrobial usage under a variety of voluntary, regulatory and legal policy frameworks. Any new approaches will ideally be structured to extend the use of present-day antimicrobials into the future, to provide novel alternatives for regulating any newly introduced antimicrobial products so as to maximize their useful life span and to ensure the optimal use of these products in animal agriculture to protect not only the health of animals and the interests of animal health/agriculture stakeholders, but also the human health and the interests of the public at large. A full range of policy approaches, which span the realm from strictly enforced regulations and laws to voluntary guidelines and compliance, should be explored with respect to their risks and benefits in a variety of worldwide settings and in full consideration of a range of stakeholder values

    Enzymatic surface hydrolysis of PET : effect of structural diversity on kinetic properties of cutinases from thermobifida

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    In this study cutinases from Thermobifida cellulosilytica DSM44535 (Thc_Cut1 and Thc_Cut2) and Thermobifida fusca DSM44342 (Thf42_Cut1) hydrolyzing poly(ethylene terephthalate) (PET) were successfully cloned and expressed in E.coli BL21-Gold(DE3). Their ability to hydrolyze PET was compared with other enzymes hydrolyzing natural polyesters, including the PHA depolymerase (ePhaZmcl) from Pseudomonas fluorescens and two cutinases from T. fusca KW3. The three isolated Thermobifida cutinases are very similar (only a maximum of 18 amino acid differences) but yet had different kinetic parameters on soluble substrates. Their kcat and Km values on pNP–acetate were in the ranges 2.4–211.9 s–1 and 127–200 ÎŒM while on pNP–butyrate they showed kcat and Km values between 5.3 and 195.1 s–1 and between 1483 and 2133 ÎŒM. Thc_Cut1 released highest amounts of MHET and terephthalic acid from PET and bis(benzoyloxyethyl) terephthalate (3PET) with the highest concomitant increase in PET hydrophilicity as indicated by water contact angle (WCA) decreases. FTIR-ATR analysis revealed an increase in the crystallinity index A1340/A1410 upon enzyme treatment and an increase of the amount of carboxylic and hydroxylic was measured using derivatization with 2-(bromomethyl)naphthalene. Modeling the covalently bound tetrahedral intermediate consisting of cutinase and 3PET indicated that the active site His-209 is in the proximity of the O of the substrate thus allowing hydrolysis. On the other hand, the models indicated that regions of Thc_Cut1 and Thc_Cut2 which differed in electrostatic and in hydrophobic surface properties were able to reach/interact with PET which may explain their different hydrolysis efficiencies.This study was performed within the Austrian Centre of Industrial Biotechnology ACIB, the MacroFun project and COST Action 868. This work has been supported by the Federal Ministry of Economy, Family and Youth (BMWFJ), the Federal Ministry of Traffic, Innovation and Technology (bmvit), the Styrian Business Promotion Agency SFG, the Standortagentur Tirol and ZIT - Technology Agency of the City of Vienna through the COMET-Funding Program managed by the Austrian Research Promotion Agency FFG. Financial support was also given from Sachsisches Staatsministerium fur Umwelt und Landwirtschaft, Germany. PET was kindly provided by Dr. Vincent Nierstrasz from Ghent University

    Changes on content, structure and surface distribution of lignin in jute fibers after laccase treatment

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    Effect of laccase treatment on the content, structure, and surface distribution of lignin in jute fibers were fundamentally investigated. Four percent lignin was removed from jute fibers via the laccase treatment. The residual lignin in the laccase-treated jute fibers showed increased molecular weights, which indicated polymerization between lignins on jute fibers. Meanwhile, the phenolic hydroxyl content in lignin decreased during the laccase oxidation accompanied by demethylation of methoxyl groups and generation of carbonyl groups. Due to the degradation and subsequent polymerization of lignin by laccase, the bulgy lignins on jute fiber surfaces were redistributed, which made the surface neat and glossy.This work was ïŹnancially supported by the National Natural Science Foundations of China (51603087, 51673087), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R26), Fundamental Research Funds for the Central Universities (JUSRP51717A), Key R&D Program of Jiangsu Province (BE2016208), Portuguese Foundation for Science and Technology (UID/BIO/04469/2013 unit), and COMPETE 2020 (POCI-01-0145-FEDER006684).info:eu-repo/semantics/publishedVersio

    Enzymatic reduction of azo and indigoid compounds

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    A customer- and environment-friendly method for the decolorization azo dyes was developed. Azoreductases could be used both to bleach hair dyed with azo dyes and to reduce dyes in vat dyeing of textiles. A new reduced nicotinamide adenine dinucleotide-dependent azoreductase of Bacillus cereus, which showed high potential for reduction of these dyes, was purified using a combination of ammonium sulfate precipitation and chromatography and had a molecular mass of 21.5 kDa. The optimum pH of the azoreductase depended on the substrate and was within the range of pH 6 to 7, while the maximum temperature was reached at 40°C. Oxygen was shown to be an alternative electron acceptor to azo compounds and must therefore be excluded during enzymatic dye reduction. Biotransformation of the azo dyes Flame Orange and Ruby Red was studied in more detail using UV-visible spectroscopy, high-performance liquid chromatography, and mass spectrometry (MS). Reduction of the azo bonds leads to cleavage of the dyes resulting in the cleavage product 2-amino-1,3 dimethylimidazolium and N∌1∌,N∌1∌-dimethyl-1,4-benzenediamine for Ruby Red, while only the first was detected for Flame Orange because of MS instability of the expected 1,4-benzenediamine. The azoreductase was also found to reduce vat dyes like Indigo Carmine (C.I. Acid Blue 74). Hydrogen peroxide (H2O2) as an oxidizing agent was used to reoxidize the dye into the initial form. The reduction and oxidation mechanism of Indigo Carmine was studied using UV-visible spectroscopy
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