Utilização de geopolímeros para controlo de pH em processos anaeróbios de valorização de resíduos orgânicos

In an anaerobic process, pH is one of the parameters which greatly influence the performance of these systems, affecting both chemical reactions and microbial activity, due to the microorganisms sensitivity to pH variations. Hence, it is essential pH control to the entire anaerobic process stability, especially when dealing with easily biodegradable substrates. The present work had as main objective the study of the long-term utilization of geopolymers for pH control in anaerobic processes for methane production, treating easily acidifiable substrates. It was used anaerobic batch reactors with 1 L of working volume and cheese whey as substrate, and performed two studies. In the first study, in order to select the concentration and type of geopolymers that promote a higher methane volume production, it were used three reactors with the addition of geopolymers with different porosity and concentrations and one reactor with the addition of chemical alkalinity (reference). The second study, in order to evaluate the long-term geopolymers performance and reproducibility, it was divided in four phases, with successive additions of substrate. So, it was used one reactor as reference and two reactors with the selected conditions in the first study (type and concentration of the geopolymers). In the first study, it was observed that the reactor with the addition of 16 g/L of geopolymers with higher porosity produced the highest methane volume. In both studies, and in general, the reactors presented a similar pH and COD performance, with an increase in COD values in the start-up period (phase 1) in the reactors with addition of geopolymers, due to the lixiviation of organic compounds from the spheres. After the various successive substrate additions, the fastest decrease in the COD values showed the capacity of organic matter removal and recovery of the system. The rapid VFA consume suggested a good adaptation of the microbial culture methane production. The results herein obtained confirm that the fly-ash containing geopolymers allow the control of pH for methane production in anaerobic processes. In light of this, this work could bring new insights to the current problems either related with pH control in AD process, or landfill disposal of fly ash and the associated environmental problems of this type of residuesNum processo anaeróbio, o pH é um dos parâmetros que mais influencia o funcionamento dos sistemas, afetando tanto as reações bioquímicas como a atividade microbiológica, devido à sensibilidade dos microorganismos a variações de pH. Assim, é essencial o controlo do pH para que haja estabilidade de todo o processo anaeróbio, especificamente quando se tratam substratos facilmente biodegradáveis. Este trabalho teve como principal objetivo estudar a utilização, a longo prazo, de geopolímeros para o controlo de pH em processos anaeróbios para produção de metano, tratando substratos facilmente acidificáveis. Foram usados reatores descontínuos anaeróbios com 1 L de volume de trabalho e soro de leite como substrato, e efetuados dois estudos. No primeiro estudo, e de modo a selecionar a concentração e tipo de geopolímeros que permitiam a maior produção de metano, utilizaram-se três reatores com adição de geopolímeros com diferente porosidade e em diferentes concentrações e um reator com adição de alcalinidade química (referência). O segundo estudo, com o objetivo de avaliar o comportamento e a reprodutibilidade da ação dos geopolímeros a longo prazo, foi dividido em quatro fases, com adições sucessivas de substrato. Para tal utilizou-se um reator como referência e dois reatores com as condições selecionadas no primeiro estudo do trabalho (tipo e concentração de geopolímeros). No primeiro estudo observou-se que o reator em que se adicionou o tipo de geopolímeros mais poroso na concentração de 16 g/L foi o que produziu maior volume de metano. Em ambos os estudos, e de um modo geral, os reatores apresentaram um comportamento semelhante em termos de evolução de pH e CQO, observando-se um aumento nos valores de CQO no período inicial (fase 1) nos reatores com adição de geopolímeros, o qual se deve à lixiviação dos seus componentes orgânicos. Após as várias adições sucessivas de substrato, a diminuição mais rápida dos valores de CQO demonstrou a capacidade de remoção de matéria orgânica e de recuperação do sistema. O rápido consumo dos ácidos orgânicos voláteis sugeriu uma boa adaptação da cultura microbiana para a produção de metano. Os resultados obtidos confirmam que é possível controlar o pH para produção de metano em processos anaeróbios, utilizando geopolímeros à base de cinzas volantes. Assim, este trabalho pode trazer novas perspetivas para os atuais problemas relacionados quer com o controlo de pH em processos de digestão anaeróbia, quer com a deposição de cinzas volantes em aterro e aos respectivos problemas ambientais associados a este tipo de resíduosMestrado em Engenharia do Ambient

Mediating towards digital inclusion: the monitors of internet access places

Local dynamics play a key role in individual and collective empowerment for digital literacy and citizenship. This paper presents the results and reflections from a broader investigation into the public Internet access places in Portugal in the inland municipalities of the country's coast, undertaken by ObLID Network. Specifically, we intend to reflect on the actual mission of these places and reveal the actual profile, activities and training needs of their monitors and coordinators. In the first stage of the empirical study, several documents available on the Internet Spaces Network are analyzed. In the second stage, a questionnaire was applied to monitors and coordinators of the Internet access places, in seventeen Portuguese municipalities. The research results warn of the need to redefine and clarify the social and educational value of Internet spaces, indicating that the dominant activities of monitors in the Internet access places do not induce the foster of literacy and digital inclusion of the most vulnerable groups. In this context, actions are proposed that can contribute to improving the mission of Internet places, as well as the training quality of their monitors and coordinators. Internet Access Spaces, made available by municipalities, should be used to promote digital literacy programs, for individuals and groups.info:eu-repo/semantics/publishedVersio

Portuguese isolates of Aspergillus section Flavi unraveled by the calmodulin gene

Aspergillus is a large genus, with a complex and ever evolving taxonomy. Section Flavi is one of the most significant sections in the genus. Taxonomy and species identification is subject of great interest for scientists aiming to clarify the species concept and limits within the section. Furthermore, this section comprises both toxigenic and non-toxigenic species/strains, with great interest to biotechnology and food industry. Various genes, namely the rRNA (ITS region), calmodulin and β-tubulin genes, have been widely reported as good markers for Aspergillus species identification, because they are rapid and cost-effective. In the present study, we evaluated the discriminatory power of the ITS region and the calmodulin gene to distinguish closely related taxa within Aspergillus section Flavi. For this purpose, 26 isolates of Aspergillus section Flavi obtained from Portuguese almonds were characterized at various levels: i) phenotypic, regarding various aspects of morphology and physiology; ii) spectral, using MALDI-TOF ICMS to obtain protein fingerprinting; and iii) genotypic, by sequence analysis of a 730 bp segment of the calmodulin gene and a 908 bp segment of the ITS region. For the various methods, dendrograms were created and results were compared. Both genotypic and spectral analyses divided the isolates in 3 groups corresponding to closely related taxa of A. flavus, A. parasiticus and A. tamarii. Except for the ITS region, all sets of analysis positioned 5 of the 26 isolates in two unidentified clades close to A. parasiticus, and divided the A. flavus group in two distinct clades. The phylogenetic analysis of the calmodulin sequences resulted in very similar dendrograms when using various methods of analysis (Neighbor-Joining, Maximum Likelihood, Bayesian Inference), and altering the analytical parameters did not result in significant changes. Furthermore, the genetic dendrograms were strongly supported by the phenotypic and spectral analyses. These results confirm the calmodulin gene as a robust and reliable genomic marker for this group of fungi. The unsolved isolate identifications are currently under further analysis

Magnetic proximity sensor based on magnetoelectric composites and printed coils

Magnetic sensors are mandatory in a broad range of applications nowadays, being the increasing interest on such sensors mainly driven by the growing demand of materials required by Industry 4.0 and the Internet of Things concept. Optimized power consumption, reliability, flexibility, versatility, lightweight and low-temperature fabrication are some of the technological requirements in which the scientific community is focusing efforts. Aiming to positively respond to those challenges, this work reports magnetic proximity sensors based on magnetoelectric (ME) polyvinylidene fluoride (PVDF)/Metglas composites and an excitation-printed coil. The proposed magnetic proximity sensor shows a maximum resonant ME coefficient (α) of 50.2 Vcm−1 Oe−1, an AC linear response (R2 = 0.997) and a maximum voltage output of 362 mV, which suggests suitability for proximity-sensing applications in the areas of aerospace, automotive, positioning, machine safety, recreation and advertising panels, among others.This research was funded by CT- Fundação para a Ciência e Tecnologia in the framework of the Strategic Funding UID/FIS/04650/2019 and under projects PTDC/EEI-SII/5582/2014, PTDC/BTM-MAT/28237/2017 and PTDC/EMD-EMD/28159/2017. A.C.L. and N.P. acknowledge also support from FCT (SFRH/BD/132624/2017 and SFRH/BD/131729/2017 grants respectively). P. Martins also thanks FCT for the contract under the Stimulus of Scientific Employment, Individual Support—2017 Call (CEECIND/03975/2017). Finally, the authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) and from the Basque Government Industry and Education Department under the ELKARTEK, HAZITEK and PIBA (PIBA-2018-06) programs, respectivel

Agro-industrial wastes as alternative substrates for the production of prebiotic with Zymomonas mobilis

Fructooligosaccharides (FOS) are promising prebiotics in the relevant and increasing market of functional food. However, to achieve a more sustainable process, the industrial production of FOS should use cheap substrates. Zymomonas mobilis (ZM) has great potential for the production of FOS due to the presence of native enzymes (levansucrase) capable of metabolizing sucrose. In addition, ZM can use different carbon sources, such as molasses and sugarcane juice, which make the FOS production process cost-effective. In this study, sugarcane molasses (a potential replacement of sucrose) and corn step liquor (CSL) (a potential replacement of yeast extract (YE)), were used as nutrients for FOS production using ZM in an in vivo bioprocess approach. FOS production process from sucrose was first optimized and 52 g/L of FOS with a yield of 0.16 g/g was obtained. Afterwards, molasses and CSL were used as alternative nutrients. After studying different combinations of CSL and YE, the highest amount of FOS (54 g/L, with a yield of 0.18 g/g) was obtained with 12 g/L of CSL and 8 g/L of YE. In addition, 45 g/L of FOS were produced from molasses containing 200 g/L of sucrose, with a yield of 0.3 g/g. With this approach, it was possible to reduce around 5.5-times the cost associated with the FOS production medium. Moreover, this study proposed a sustainable process for the valorization of agro-industrial wastes contributing to the future Circular (Bio)Economy and the EU Green Deal.Cláudia Amorim, João Rainha, Beatriz B. Cardoso and Daniela Gomes acknowledge their grants (2020.0029.CEECIND, SFRH/BD/138325/2018, SFRH/BD/132324/2017 and SFRH/BD/04433/2020, respectively) from Portuguese Foundation for Science and Technology (FCT). The study received financial support from Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020.info:eu-repo/semantics/publishedVersio

Zymomonas mobilis an emerging microbial cell factory to produce prebiotics

info:eu-repo/semantics/publishedVersio

Avaliação da qualidade e segurança microbiológica de refeições de sushi prontas a consumir em Portugal

Being a food product that contains perishable ingredients and involves a significant degree of manual handling during preparation, sushi is regarded as a potentially hazardous food, which may lead to foodborne disease outbreaks. In Portugal, consumption of takeaway sushi meals has strongly increased throughout the past few years; however, there is limited information regarding its compliance with food quality standards. Under this context, the present study aimed to evaluate the microbiological quality and safety of take-away ready-to-eat sushi meals in Lisbon, Portugal. Sixty- two samples were collected from different origins (restaurant and hypermarket), and each sample was tested for aerobic mesophilic microorganisms, Enterobacteriaceae, Escherichia coli, positive coagulase Staphylococci, presumptive Bacillus cereus count, as for detection of pathogenic microorganisms, such as Salmonella spp., Listeria monocytogenes and Vibrio parahaemolyticus, V. cholerae and V. vulnificus. Results revealed that 48.4% (30/62) were deemed unsatisfactory, 35.5% (22/62) were classified as borderline and only 16.1% (10/62) were considered satisfactory. Even though we did not detect the incidence of potentially pathogenic microorganisms in sushi, the presence of B. cereus and coagulase- positive Staphylococci was detected at unsatisfactory levels. Furthermore, significant differences between the place of origin (restaurant vs. hypermarket) and type of fish were also observed. Overall, the high number of samples classified with a level of microbiological quality “unsatisfactory” and “borderline” highlights the need to review good hygiene practices, as well as the quality of the raw materials used, to obtain a final product with a satisfactory quality and safety levelRESUMO - Por ser um género alimentício que contém ingredientes perecíveis e envolve um grau significativo de manipulação manual durante a sua preparação, o sushi é considerado um alimento potencialmente perigoso, que pode causar surtos de doença de origem alimentar. Em Portugal, o consumo de refeições de sushi prontas a consumir tem aumentado ao longo dos últimos anos. No entanto, a informação sobre o cumprimento das normas de qualidade alimentar é limitada. Neste contexto, o presente estudo teve como objetivo avaliar a qualidade e a segurança microbiológica de refeições de sushi prontas para consumo em take-way, na região de Lisboa, Portugal. Foram colhidas 62 amostras de diferentes origens (restaurante e hipermercado), e em cada amostra foi efetuada a contagem de microrganismos aeróbios mesófilos, Enterobacteriaceae, Escherichia coli, estafilococos coagulase positiva, Bacillus cereus presuntivos, e deteção de microrganismos patogénicos, tais como: Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, Vibrio cholerae e Vibrio vulnificus. Os resultados revelaram que 48,4% (30/62) das amostras foram consideradas insatisfatórias, 35,5% (22/62) foram classificadas como “borderline” e apenas 16,1% (10/62) foram consideradas como satisfatórias. Embora não tenham sido detetados microrganismos potencialmente patogénicos nas amostras de sushi, a presença de B. cereus e estafilococos coagulase positivos foram detetados em níveis insatisfatórios. Além disso, também foram observadas diferenças significativas entre o local de origem (restaurante vs. hipermercado) e tipo de peixe. No geral, o elevado número de amostras classificadas com um nível de qualidade microbiológica insatisfatória e “borderline” evidência a necessidade de revisão das boas práticas de higiene, bem como da qualidade das matérias- primas utilizadas, para obter um produto final com qualidade e segurança satisfatóriainfo:eu-repo/semantics/publishedVersio

Zymomonas mobilis: a promising microorganism for prebiotic production

Zymomonas mobilis (ZM) is an ethanologenic bacterium with outstanding characteristics which makes it an interesting chassis for the biotechnological production of prebiotics. Fructooligosaccharides (FOS) are promising prebiotics in the increasing market of functional food. In this work, a Box-Behnken design approach was used to optimize the medium composition and maximize the FOS content. Under optimal conditions, 45.3 g/L of FOS were obtained. Sucrose was the most significant variable; thus, its concentration was further increased to 350 g/L leading to a 1.13-fold enhance in FOS titer. Afterwards, a scale-up to bioreactor was performed resulting in a high yield, content and productivity of FOS (58 %, 156.5 g/L 4.8 g/L h). Furthermore, 45 g/L of sorbitol and 8 g/L of levan were also produced. After purification of the FOS mixture through an activated charcoal column, an in vitro model using human fecal inoculum was used to assess its prebiotic potential. The results suggest that the produced prebiotic mixture has potential to be used to improve the human health. The present work describes for the first time the production of a prebiotic mixture with ZM ZM4 in an in vivo single-step approach that has potential to be commercialized as functional food ingredient.João Rainha, Beatriz B. Cardoso and Daniela Gomes acknowledge their grants (UMINHO/BPD/4/2019, SFRH/BD/138325/2018, SFRH/BD/132324/2017, and SFRH/BD/04433/2020, respectively) from Portuguese Foundation for Science and Technology (FCT). The study received financial support from Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and the project FoSynBio (POCI-01-0145-FEDER-029549).info:eu-repo/semantics/publishedVersio

Bioengineered cell culture systems of central nervous system injury and disease

Cell culture systems, either 2D or explant based, have been pivotal to better understand the pathophysiology of several central nervous system (CNS) disorders. Recently, bioengineered cell culture systems have been proposed as an alternative to the traditional setups. These innovative systems often combine different cell populations in 3D environments that more closely recapitulate the different niches that exist within the developing or adult CNS. Given the importance of such systems for the future of CNS-related research, we discuss here the most recent advances in the field, particularly those dealing with neurodegeneration, neurodevelopmental disorders, and trauma.Financial support is acknowledged from Prémios Santa Casa Neurociências – Prize Melo e Castro for Spinal Cord Injury Research; Portuguese Foundation for Science and Technology [Doctoral fellowship (SFRH/BD/103075/2014) to E.D.G.; IF Development Grant to A.J.S.; Starting Grant to F. Marques; PostDoctoral fellowship SFRH/BPD/97701/2013 to N.A.S.]; this work was co-funded by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), ao abrigo do Quadro de Referência Estratégico Nacional (QREN), através do Fundo Europeu de Desenvolvimento Regional (FEDER).info:eu-repo/semantics/publishedVersio