Possibilities for recycling cellulases after use in celllase processing - part I: effects of end-product inhibition, thermal and mechanical deactivation, and cellulase depletion by adsorption

Preliminary recycling experiments with cellulase enzymes after cotton treatments at 50°C showed that activity remaining in the treatment liquors was reduced by about 80% after five recycling steps. The potential problems of end-product inhibition, thermal and mechanical deactivation, and the loss of some components of the cellulase complex by preferential and or irreversible adsorption to cotton substrates were studied. End-product inhibition studies showed that the build-up of cellobiose and glucose would be expected to cause no more than 40% activity loss after five textile treatment cycles. Thermal and mechanical treatments of cellulases suggested that the enzymes start to be deactivated at 60°C and agitation levels similar to those used in textile processing did not cause significant enzyme deactivation. Analysis of cellulase solutions, by fast protein liquid chromatography, before and after adsorption on cotton fabrics, suggested that the cellobiohydrolase II (Cel6A) content of the cellulase complex was reduced, relative to the other components, by preferential adsorption. This would lead to a marked reduction in activity after several treatment cycles and top-up with pure cellobiohydrolase II would be necessary unless this component is easily recoverable from the treated fabric

Effects of temperature on the cellulose binding ability of cellulase enzymes

The effects of high temperatures on catalytic activity and binding abilities of crude Trichoderma reesei cellulases in solution and adsorbed to a cotton fabric were studied. Above optimum temperature of 50 degrees C, catalytic activities were severely diminished but the binding behaviour was not found to be adversely affected. In order to verify possible applications of cellulases adsorbed to cotton fabrics as anchors for textile finishing purposes, we also checked the binding abilities after ironing. Previous ironing of cellulase adsorbed fabrics increased dyeability with an acid dye, but dye fastness was poor. Desorption of cellulases from cotton fabrics increased from pH 5 to pH 10. Dry ironing of fabrics resulted in less desorption, whereas wet ironing inhibited desorption at pH 5 and only 11% of protein were desorbed at pH 10. Ironing of the fabrics diminished enzyme activity of desorbed cellulases. Wet ironing resulted in complete denaturation of the proteins and no cellulolytic activity was found. The presence of water during thermal treatment of cellulases was found to be essential for complete denaturation and unfolding of the proteins. Dry heat only resulted in partial denaturation. Fluorescence measurements of cellulases adsorbed to cotton fabrics showed after ironing a significant shift in tryptophan fluorescence to higher wavelengths. This indicates unfolding and denaturation of the enzymes and revelation of more hydrophobic amino acids to the surface, which enables increased hydrophobic interactions with the fabric. (C) 1999 Elsevier Science B.V. All rights reserved

Possibilities for recycling cellulases after use in cotton processing - part II: Separation of cellulases from reaction products and released dyestuffs by ultrafiltration

The adsorption and activity of a total cellulase (Trichoderma reesei) was measured and compared on undyed and dyed cotton fabrics. Recovery of enzymes from the reaction mixture and by desorption from the cotton substrate was evaluated. About 80% of the initial protein could be recovered. The removal of released products (soluble reducing sugars and dyes) from the treatment liquor and subsequent concentration of cellulase proteins was performed using an ultrafiltration membrane. Strong protein-dye interactions made it impossible to separate efficiently the dyes from the enzymecontaining treatment liquors. The use of surfactants did not enhance cellulase desorption from cotton fabric. Although anionic surfactants have a deactivating effect on cellulases, this effect seems to be reversible, since after ultrafiltration the cellulase activity was similar to that of enzymes desorbed with buffer only. Humicola insolens cellulases were shown to be much more sensitive to anionic surfactant than T. reesei cellulases. The use of cellulases that bind reversibly to cellulose is suggested for achieving more efficient cellulase recycling and for reducing backstaining by dye-cellulase complexes

Effects of agitation level on the adsorption, desorption, and activities on cotton fabrics of full length and core domains of EGV(humicola insolens) and CenA (cellulomonas fimi)

The activities (at pH 7 and 50 degrees C) of purified EGV (Humicola insolens) and CenA (Cellulomonas fimi) were determined on cotton fabrics at high and low levels of mechanical agitation. Similar activity measurements were also made by using the core domains of these cellulases. Activity experiments suggested that the presence of cellulose binding domains (CBDs) is not essential for cellulase performance in the textile processes, where high levels of mechanical agitation are applied. The binding reversibilities of these cellulases and their cores were studied by dilution of the treatment liquor after equilibrium adsorption. EGV showed low percentage of adsorption under both levels of agitation. It was observed that the adsorption/desorption processes of cellulases are enhanced by higher mechanical agitation levels and that the binding of cellulase with CBD of family I (EGV) is more reversible than that of CBD of the cellulase of family II (CenA). (C) 2000 Elsevier Science Inc. All rights reserved

Correlation between the spread of COVID-19 and the Interest in personal protective measures in Poland and Portugal

This research initiated during Artur Strzelecki’s research stay at Polytechnic Institute of Porto, Portugal.The pandemic of the coronavirus disease 2019 (COVID-19), has gained extensive coverage in public media and global news, generated international and national communication campaigns to educate the communities worldwide and raised the attention of everyone. The coronavirus has caused viral pneumonia in tens of thousands of people around the world, and the COVID-19 outbreak changed most countries’ routines and concerns and transformed social behaviour. This study explores the potential use of Google Trends (GT) in monitoring interest in the COVID-19 outbreak and, specifically, in personal protective equipment and hand hygiene, since these have been promoted by official health care bodies as two of the most protective measures. GT was chosen as a source of reverse engineering data, given the interest in the topic and the novelty of the research. Current data on COVID-19 are retrieved from GT using keywords in two languages—Portuguese and Polish. The geographical settings for GT are two countries: Poland and Portugal. The period under analysis is 20 January 2020, when the first cases outside China were known, to 15 June 2020. The results show that there is a correlation between the spread of COVID-19 and the search for personal protective equipment and hand hygiene and that GT can help, to a certain extent, understand people’s concerns, behaviour and reactions to sanitary problems and protection recommendationsinfo:eu-repo/semantics/publishedVersio

Desorption of cellulases from cotton powder

Cotton fabrics were treated with three different Trichoderma reesei cellulase preparations (total crude – TC, endoglucanase enriched – EG-rich, cellobiohydrolase enriched – CBH-rich) using mechanical agitation to produce cotton powder. Desorption of cellulase enzymes from the cotton powder was then performed by washing with buffer. After 3 washings most of the protein was desorbed from the cotton powder and the amount of sugars released in the latter washings was negligible. TC and CBH-rich preparations produced a finer cellulose powder than EGs. The desorption process caused a decrease in degree of polymerisation (DP) specially for the cotton treated with EGs and a marked increase in polydispersity (Pd ) for all preparations

SEEDS SA: caso pedagógico de negociação comercial

Este Caso Pedagógico tem como principal objectivo, detalhar as fases que constituem uma negociação através da sua aplicação prática, recorrendo a um processo negocial que se insere na Indústria Portuguesa de Gestão de Activos. O processo negocial desde a sua preparação até à implementação do acordo, as estratégias e tácticas negociais bem como os perfis dos negociadores, são abordados no Caso. A Negociação de Objectivos Comerciais, que ocorre anualmente, entre a Sociedade Gestora de Fundos de Investimento - Seeds SA e o seu principal cliente - Banco Green, constituirão a base de aplicação dos conceitos analisados ao longo da revisão de literatura, construída através de artigos científicos, livros publicados por autores nacionais e internacionais que se debruçaram sobre o estudo da negociação comercial.This Case Study has its main purpose to detail the steps that constitute the negotiation process through its practical application, in the Portuguese Asset Management Industry. The negotiating process from preparation to implementation of the agreement, negotiation strategies and tactics as well as the profiles of the negotiators, are covered in the case. The negotiation of Business goals, that occurs every year, between the Asset Management Company - Seeds SA and its main client - Green Bank, provides the basis for applying the concepts discussed throughout the literature review that was built with scientific articles and books written by portuguese and international authors who have study commercial negotiation

As organizações sociais como modelo (im)próprio para o atingimento da eficiência administrativa: um estudo de caso da implementação do modelo no município de Florianópolis

TCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Jurídicas. Direito.Esta monografia investiga a eficiência administrativa no modelo das Organizações Sociais e o problema que orientou o trabalho foi: o modelo das Organizações Sociais é adequado para o atingimento da eficiência administrativa? A hipótese que se buscou confirmar é de que o modelo das Organizações Sociais, do modo quem vem sendo implementado, não é adequado para o atingimento da eficiência administrativa. Para tanto, utilizou-se o método de abordagem dedutivo por meio dos procedimentos de pesquisa bibliográfica e estudo de caso. O objetivo geral do trabalho consistiu em verificar se o modelo das Organizações Sociais é próprio ou impróprio para o atingimento da eficiência administrativa. Constituíram objetivos específicos da pesquisa: analisar o princípio da eficiência administrativa em sua harmonia constitucional; analisar o modelo federal das Organizações Sociais, por ser o modelo de base para as demais implementações e; verificar, através de um estudo de caso, se o modelo de Organização Social, implementado no Município de Florianópolis, cumpre requisitos de eficiência traçados na intersecção entre o princípio da eficiência administrativa, em harmonia com os demais princípios constitucionais, e o modelo das Organizações Sociais. Ao final da pesquisa a hipótese foi parcialmente confirmada, em decorrência de que o modelo precisa ser muito trabalhado para se tornar efetivamente adequado, ainda que possua características de adequação