Laccase immobilization on enzymatically functionalized polyamide 6,6 fibres

Polyamide matrices, such as membranes, gels and non-wovens, have been applied as supports for enzyme immobilization, although in literature the enzyme immobilization on woven nylon matrices is rarely reported. In this work, a protocol for a Trametes hirsuta laccase immobilization using woven polyamide 6,6 (nylon) was developed. A 24 full factorial design was used to study the influence of pH, spacer (1,6-hexanediamine), enzyme and crosslinker concentration on the efficiency of immobilization. The factors enzyme dosage and spacer seem to have played a critical role in the immobilization of laccase onto nylon support. Under optimized working conditions (29 U mL−1 of laccase, 10% of glutaraldehyde, pH = 5.5, with the presence of the spacer), the half-life time attained was about 78 h (18% higher than that of free enzyme), the protein retention was 30% and the immobilization yield was 2%. The immobilized laccase has potential for application in the continuous decolourization of textile effluents, where it can be applied into a membrane reactor

Assessment of the adequacy of different Mediterranean waste biomass types for fermentative hydrogen production and the particular advantage of carob (Ceratonia siliqua L.) pulp

ABSTRACT: The conversion of agro-industrial byproducts, residues and microalgae, which are representative or adapted to the Mediterranean climate, to hydrogen (H2) by C. butyricum was compared. Five biomass types were selected: brewery’s spent grain (BSG), corn cobs (CC), carob pulp (CP), Spirogyra sp. (SP) and wheat straw (WS). The biomasses were delignified and/or saccharified, except for CP which was simply submitted to aqueous extraction, to obtain fermentable solutions with 56.2e168.4 g total sugars L 1. In small-scale comparative assays, the H2 production from SP, WS, CC, BSG and CP reached 37.3, 82.6, 126.5, 175.7 and 215.8 mL (g biomass) 1, respectively. The best fermentable substrate (CP) was tested in a pH-controlled batch fermentation. The H2 production rate was 204 mL (L h) 1 and a cumulative value of 3.9 L H2 L 1 was achieved, corresponding to a H2 production yield of 70.0 mL (g biomass) 1 or 1.6 mol (mol of glucose equivalents) 1. The experimental data were used to foresight a potential energy generation of 2.4 GWh per year in Portugal, from the use of CP as substrate for H2 production.info:eu-repo/semantics/publishedVersio

Coffee industrial waste as a natural source of bioactive compounds with antibacterial and antifungal activities

Coffee is one of the most popular and consumed beverages in the world, which leads to a high contents of solid residue known as spent coffee grounds (SCG). As is known, coffee beans contain several classes of health related chemicals, including phenolic compounds, melanoidins, diterpenes, xanthines and carotenoids which are associated with therapeutic and pharmaceutical effects, due to antimicrobial, antioxidant, anti-infectious and antitumour activities. Considering that this coffee industrial waste has no commercial value and are currently disposed as a solid waste or employed as fertilizers, we intend to highlight the use of SCG as a raw material with potential interest to the food and pharmaceutical industries. Moreover, this work seems to be valuable to promote the use of SCG as natural and an inexpensive food supplements or pharmaceutical additive. The phytochemical compounds content among the crude aqueous extracts of SCG followed this order: phenolics > flavonoids > carotenoids (mg/ g dry waste), respectively. Caffeine content found in SCG was ~ 0.82 g/100 g dry waste, 70 % lower than coffee roasting beans. Coffee ground extracts showed inhibition to S. aureus and E. coli growth for concentrations of 1.0 mg/ mL and a stronger inhibition was also observed against C. albicans, C. krusei and C. parapsilosis growth using lower concentration (0.5 mg/ mL).info:eu-repo/semantics/publishedVersio

Alkali and acid polysaccharides blend nanofibrous membranes prepared by electrospinning

Poster apresentado no "Smart and functional coatings conference", Torino, Italy, 2013Electrospinning allows the production of polymer fibres with diameters in the sub-micron size range, through the application of an external electric field, keeping intact the bulk properties of the polymers. Electrospun membranes possess some unique structural features, such as a high surface to volume ratio and very good mechanical performance, properties that are determinant to their use in several applications such as air and liquid filtration, tissue engineering, optical and chemical sensors [1]. In this work, alkali and acid biopolysaccharides blended with polyvinyl alcohol (PVA) were electrospinned into a polyvinylidene difluoride (PVDF) basal microfiltration membrane, with the goal of developing a mid-layer nanofibrous porous support for exploitable thin-film composite (TFC) membranes for water filtration. The alkali and acid biopolysaccharides chosen were, respectively, chitosan (CS), a cationic polyelectrolyte (in this case with deacetylation degree around 85), and cyanobacterial extracellular polymeric substances (EPS), an acidic polysaccharide isolated from Cyanothece sp.CCY 0110 [2]. The electrospun blended nanofibrous membranes were fully characterized in order to investigate their morphology, diameter, structure, mechanical and thermal properties. The results showed that these membranes have great potential for filtration purposes [3].This work was funded by FEDER funds through the Operational Competitiveness Programme – COMPETE and by National Funds through FCT – Fundação para a Ciência e a Tecnologia under the projects FCOMP-01-0124-FEDER-022718 (PEst-C/SAU/LA0002/2011), FCOMP-01-0124-FEDER-009389 (PTDC/CTM/100627/2008) and FCOMP-01-0124-FEDER-009697 (PTDC/EBB-EBI/099662/2008), and the grants SFRH/BPD/37045/2007 and SFRH/BPD/72400/2010. The authors also thank to the project INVISIBLE NETWORK nº. 13857 * SI I&DT Mobilizador

Coffee industrial waste as a natural source of bioactive compounds with antibacterial and antifungal activities

Coffee is one of the most popular and consumed beverages in the world, which leads to a high contents of solid residue known as spent coffee grounds (SCG). As is known, coffee beans contain several classes of health related chemicals, including phenolic compounds, melanoidins, diterpenes, xanthines and carotenoids which are associated with therapeutic and pharmaceutical effects, due to antimicrobial, antioxidant, anti-infectious and antitumour activities. Considering that this coffee industrial waste has no commercial value and are currently disposed as a solid waste or employed as fertilizers, we intend to highlight the use of SCG as a raw material with potential interest to the food and pharmaceutical industries. Moreover, this work seems to be valuable to promote the use of SCG as natural and an inexpensive food supplements or pharmaceutical additive. The phytochemical compounds content among the crude aqueous extracts of SCG followed this order: phenolics > flavonoids > carotenoids (mg/ g dry waste), respectively. Caffeine content found in SCG was ~ 0.82 g/100 g dry waste, 70 % lower than coffee roasting beans. Coffee ground extracts showed inhibition to S. aureus and E. coli growth for concentrations of 1.0 mg/ mL and a stronger inhibition was also observed against C. albicans, C. krusei and C. parapsilosis growth using lower concentration (0.5 mg/ mL).info:eu-repo/semantics/publishedVersio

Prevention of the dating violence: intervention with youngsters in school context

A investigação da violência no namoro tem demonstrado a importância da prevenção junto das populações juvenis. Descreve-se uma experiência de prevenção nesse domínio. Os objetivos foram promover a aquisição de conhecimentos acerca do fenômeno; capacitar para o reconhecimento de situações íntimas abusivas; identificar e produzir mudanças nas crenças sócio-culturais que sustentam esse tipo de violência; desenvolver competências para gerir uma situação de violência pelo parceiro; informar acerca dos recursos na comunidade. Os dois ensaios desenvolvidos foram avaliados em diferentes momentos (pré e pós-teste) e um dos ensaios incluiu ainda uma avaliação follow-up. Uma avaliação qualitativa do programa foi também considerada. Na avaliação da eficácia destas intervenções concluímos que as ações desenvolvidas têm efeitos positivos para ambos os sexos, traduzindo-se numa menor tolerância dos participantes face à violência. A concluir, refletimos sobre as limitações deste tipo de ações e apresentamos formas de aperfeiçoar a prevenção junto dos jovens.La investigación de la violencia en el enamoro ha demostrado la importancia de la prevención junto a las poblaciones juveniles. Se describe una experiencia de prevención en ese dominio. Los objetivos fueron promover la adquisición de conocimientos acerca del fenómeno; capacitar para el reconocimiento de situaciones íntimas abusivas; identificar y producir cambios en las creencias socio-culturales que sustentan ese tipo de violencia; desarrollar competencias para administrar una situación de violencia por la pareja; informar acerca de los recursos en la comunidad. Los dos ensayos desarrollados fueron evaluados en diferentes momentos (pré y póst-test) y un de los ensayos incluyó también una evaluación follow-up. Una evaluación cualitativa del programa fue también considerada. En la evaluación de la eficacia de estas intervenciones concluimos que las acciones desarrolladas tienen efectos positivos para ambos sexos, traduciéndose en una menor tolerancia de los participantes frente a la violencia. Al concluir reflexionamos sobre las limitaciones de este tipo de acción y presentamos formas de perfeccionar la prevención junto a los jóvenes.Research on intimate violence has pointed out the importance of prevention in younger populations. Two experiences of dating violence prevention are described. Aims: (1) promoting the acquisition of knowledge about this problem, (2) enabling youths to recognize abuse in close relationships; (3) producing changes in cultural beliefs that support violence; (4) providing generic abilities to manage situations of dating violence; (5) informing about resources in the community. The beliefs of the participants were assessed in two moments - pre-test and post-test - and in one of the programs it was also possible to include a follow-up evaluation. The qualitative evaluation of the program made by the participants was also considered. The evaluation of these interventions shows that the intervention reduces the level of tolerance towards violence in both males and females. At the end of the paper major limitations are discussed, as well strategies to minimize these problems in future research.Fundação para a Ciência e a Tecnologia (FCT

Charcos Temporários do Sul de Portugal

Este livro oferece, de uma forma simplificada, uma visão integrada da biodiversidade dos charcos temporários da região Sul de Portugal Continental, com especial enfâse para as espécies de flora características destas habitats

Evaluation of Jerusalem artichoke as a sustainable energy crop to bioethanol: energy and CO(2)eq emissions modeling for an industrial scenario

ABSTRACT: An alternative to the sugar/starch-based crops bioethanol is lignocellulosic biomass, but its utilization to biofuels is still not economically viable. In this context, an increasing interest has arising on the search for specific energy crops that do not require arable lands and are not water intensive, such as Jerusalem artichoke (JA). So, this work consisted on the cultivation of JA on those agricultural conditions and its further evaluation as a sustainable feedstock towards bioethanol. Two strategies of producing bioethanol were evaluated pointing out for the consolidated bioprocessing with the Zygosaccharomyces bailii Talf1 yeast as the best approach for further scale-up, based on energy data analysis and ethanol productivity. Different industrial scenarios were outlined and compared for overall CO(2)eq emissions and energy consumption per liter of ethanol (L-EtOH), using adequate criteria on a cradle-to-gate approach. With no land-use change, no biogenic and no co-products credits, the comparison of the overall energy consumption and CO(2)eq emissions (100% process) from JA ethanol (9 MJ/L-EtOH; 679 g CO2/L-EtOH) with sugarcane/sugar beet ethanol (42/29 MJ/L-EtOH; 731/735 g CO2/L-EtOH) and with gasoline refinery (15 MJ/L-EtOH eq; 1154 g CO2/L-EtOH eq), highlights the JA as an alternative feedstock to be a focus of ethanol research for gasoline blends.info:eu-repo/semantics/publishedVersio

Theoretical Study of the Thermolysis Reaction and Chemiexcitation of Coelenterazine Dioxetanes

Coelenterazine and other imidazopyrazinones are important bioluminescent substrates widespread in marine species and can be found in eight phyla of luminescent organisms. Light emission from these systems is caused by the formation and subsequent thermolysis of a dioxetanone intermediate, whose decomposition allows for efficient chemiexcitation to singlet excited states. Interestingly, some studies have also reported the involvement of unexpected dioxetane intermediates in the chemiand bioluminescent reactions of Coelenterazine, albeit with little information on the underlying mechanisms of these new species. Herein, we have employed a theoretical approach based on density functional theory to study for the first time the thermolysis reaction and chemiexcitation profile of two Coelenterazine dioxetanes. We have found that the thermolysis reactions of these species are feasible but with relevant energetic differences. More importantly, we found that the singlet chemiexcitation profiles of these dioxetanes are significantly less efficient than the corresponding dioxetanones. Furthermore, we identified triplet chemiexcitation pathways for the Coelenterazine dioxetanes. Given this, the chemiexcitation of these dioxetanes should lead only to minimal luminescence. Thus, our theoretical investigation of these systems indicates that the thermolysis of these dioxetanes should only provide dark pathways for the formation of nonluminescent degradation products of the chemi- and bioluminescent reactions of Coelenterazine and other imidazopyrazinones