Novel submerged photocatalytic membrane reactor for treatment of olive mill wastewaters

POCI-01-0145-FEDER-007265A new hybrid photocatalytic membrane reactor that can easily be scaled-up was designed, assembled and used to test photocatalytic membranes developed using the sol–gel technique. Extremely high removals of total suspended solids, chemical oxygen demand, total organic carbon, phenolic and volatile compounds were obtained when the hybrid photocatalytic membrane reactor was used to treat olive mill wastewaters. The submerged photocatalytic membrane reactor proposed and the modified membranes represent a step forward towards the development of new advanced treatment technology able to cope with several water and wastewater contaminants.publishersversionpublishe

Solvent-free process for the development of photocatalytic membranes

PTDC/EAM-AMB/30989/2017.This work described a new sustainable method for the fabrication of ceramic membranes with high photocatalytic activity, through a simple sol-gel route. The photocatalytic surfaces, prepared at low temperature and under solvent-free conditions, exhibited a narrow pore size distribution and homogeneity without cracks. These surfaces have shown a highly efficient and reproducible behavior for the degradation of methylene blue. Given their characterization results, the microfiltration photocatalytic membranes produced in this study using solvent-free conditions are expected to effectively retain microorganisms, such as bacteria and fungi that could then be inactivated by photocatalysis.publishe

Hydrogen producing microbial communities of the biocathode in a microbial electrolysis cell

In the search for alternatives for fossil fuels and the reuse of the energy from waste streams, the microbial electrolysis cell is a promising technique. The microbial electrolysis cell is a two electrode system in which at the anode organic substances, including waste water, are used by microorganisms that release the terminal electrons to the electrode. These electrons are subsequently used at the cathode resulting in the production of a current. By addition of a small voltage, hydrogen gas can be produced by combining electrons and protons at the cathode. To catalyse the hydrogen evolution reaction at the cathode, expensive catalysts such as platinum are required. Recently, the use of biocathodes has shown great potential as an alternative for platinum. The microbial community responsible for the hydrogen evolution in such systems is, however, not well understood. In this study we focused on the characterization of the microbial communities of the microbial electrolysis cell biocathode using molecular techniques. The results show that the microbial community consists of 44% Proteobacteria, 27% Firmicutes, 18% Bacteriodetes and 12% related to other phyla. Within the major phylogenetic groups we found several clusters of uncultured species belonging to novel taxonomic groups at genus level. These novel taxonomic groups developed under environmentally unusual conditions and might have properties that have not been described before. Therefore it is of great interest to study those novel groups further. Within the Proteobacteria a major cluster belonged to the Deltaproteobacteria and based on the known characteristics of the closest related cultured species, we suggest a mechanism for microbial electron transfer for the production of hydrogen at the cathode

Synthesis of bis-amino acid derivatives by Suzuki cross-coupling, Michael addition and substitution reactions

Several bis-amino acids were prepared using a bis-Suzuki coupling (compounds 4-8, 10), a sequential Michael addition and bis-Suzuki coupling (compounds 12, 13) and a Michael addition followed by a substitution reaction (compounds 18, 19). Thus, the pure stereoisomer of the methyl esters of N-(tert-butoxycarbonyl)-beta-bromodehydroaminobutyric acid and dehydrophenylalanine and of N-benzyloxycarbonyl-beta-bromodehydroaminobutyric acid were reacted with 1,4-phenylene-bis-boronic acid or 9,9-dioctyl-9H-fluorene-2,7-bis-boronic acid using modified Suzuki coupling conditions. The corresponding bis-dehydroamino acid derivatives were obtained in good to high yields maintaining the stereochemistry of the starting materials. This reaction was also applied successfully to a brominated dehydrodipeptide and 1,4-phenylene-bis-boronic acid showing that it could be used to create cross-links in peptide chains. An N,N-diacyldehydroalanine derivative was used in a sequential Michael addition and bis-Suzuki coupling giving a p-terphenyl bis-amino acid and a fluorenyl bis-amino acid in good yields. Two bis-alpha,beta-diamino acids were obtained by a Michael addition of 1,2,4-triazole to the methyl esters of N-(4-toluenesulfonyl), N-(tert-butoxycarbonyl) dehydroamino acids followed by treatment with ethylenediamine.We acknowledge the Foundation for Science and Technology (FCT), Portugal and the Fundo Europeu de Desenvolvimento Regional (FEDER) for financial support through the Centro de Quimica of University of Minho and through the project POCI/QUI/59407/2004

Passion fruit: a functional food?

Este artigo é uma revisão bibliográfica sobre as espécies brasileiras de Passiflora (Passiflora edulis fo. flavicarpa O. Deg., P. alata Curtis e P. edulis fo. edulis). A maioria dos artigos da literatura focaliza somente as folhas de Passiflora, enquanto que esta revisão contém informações sobre a polpa, cascas e sementes dos frutos do maracujá, com destaque para a composição química, estudos nutricionais e farmacológicos. O enfoque nos frutos do maracujá fundamenta-se no amplo consumo do suco de maracujá (fresco ou industrializado) no Brasil e também nas investigações em andamento para avaliar o seu potencial uso como alimento funcional.This paper consists of a bibliographic review of the most relevant edible Brazilian Passiflora species (Passiflora edulis fo. flavicarpa O. Deg., P. alata Curtis and P. edulis fo. edulis). Most of the reports in the literature focus solely on Passiflora leaves, whereas this review contains information about passion fruit pulp, rind and seeds, highlightening chemical composition, nutritional and pharmacological studies. The emphasis on the "maracujá" fruit is due to the extensive consumption of passion fruit juice (fresh or processed) in Brazil and on ongoing investigations into its potential as a functional food.FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

Modulation of butyrate-degrading methanogenic communities by conductive materials

Butyrate is a volatile fatty acid commonly present in anaerobic bioreactors. Previous research showed that methane production (MP) rates from butyrate, by lake sediment microbiomes, doubled by addition of carbon nanotubes, which was accompanied by changes in the microbial community composition, with enrichment of typical fatty-acid degrading bacteria (Syntrophomonas spp.), well known to exchange electrons with methanogens via hydrogen or formate formation1. But the authors suggested that electrons exchange via conductive materials (CM) may take place instead. In our study, anaerobic butyrate-degrading enrichment cultures were developed with other CM, namely activated carbon (AC) and magnetite (Mag) at 0.5 g/L. MP started earlier in AC enrichment and complete degradation was achieved faster in Mag enrichment. Syntrophomonas spp. were enriched in all cultures (representing 60 to 80 % of the total bacterial community), but hydrogenotrophic methanogens were highly stimulated by AC (78 % of Methanomicrobiales), while the methanogenic community of Mag culture was more diverse in acetoclastic methanogens (43% of Methanosarcina and Methanosaeta). It is still unclear if the improvement on butyrate degradation is associated to the role of CM in interspecies electron transfer, but it is undoubtful that they differentially modulate the methanogenic communities towards faster MP.info:eu-repo/semantics/publishedVersio

Eugenol β-amino/β-alkoxy alcohols with selective anticancer activity

Eugenol, 4-allyl-2-methoxyphenol, is the main constituent of clove essential oil and has demonstrated relevant biological activity, namely anticancer activity. Aiming to increase this activity, we synthesized a series of eugenol β-amino alcohol and β-alkoxy alcohol derivatives, which were then tested against two human cancer cell lines, namely gastric adenocarcinoma cells (AGS) and lung adenocarcinoma cells (A549). An initial screening was performed to identify the most cytotoxic compounds. The results demonstrated that three β-amino alcohol derivatives had anticancer activity that justified subsequent studies, having been shown to trigger apoptosis. Importantly, the most potent molecules displayed no appreciable toxicity towards human noncancer cells. Structure-activity relationships show that changes in eugenol structure led to enhanced cytotoxic activity and can contribute to the future design of more potent and selective drugs.This research was funded by FCT under project PTDC/ASP-AGR/30154/2017 (PO-CI-01-0145- FEDER-030154) of COMPETE 2020, co-financed by FEDER and EU. FCT-Portugal and FEDERCOMPETE/ QREN-EU also gave financial support to the research centres CQ/UM (UIDB/00686/2020) and REQUIMTE (UIDB/50006/2020). The NMR spectrometer Bruker Avance III 400 (part of the National NMR Network) was financed by FCT and FEDER. Renato B. Pereira acknowledges PRIMA Foundation (H2020- PRIMA 2018—Section 2, Project MILKQUA) and FCT (PTDC/QUI-QFI/2870/2020) for the funding

Differential effects of carbon-based and iron-based conductive materials in anaerobic butyrate-degrading enrichments

Introduction Conductive materials (CM) accelerate methane production (MP), probably by promoting more efficient interactions between bacteria and methanogens. This work investigates the effects of activated carbon (AC) and magnetite (Mag) in microbial enrichments degrading butyrate. Three different butyrate-degrading enrichments were developed: 1) without CM, 2) with AC, or 3) with Mag. It was also investigated if the effect of CM persisted when CM-adapted enrichments were transferred to new medium without CM, and if CM affected the activity of stable enrichments without previous contact with CM. Methodology Enrichment series were initiated with granular anaerobic sludge as inoculum, butyrate (10 mmol/L) as substrate, and CM (0.5 g/L AC or 0.5 g/L Mag), or without CM, and incubated at 37 °C, under strict anaerobic conditions. The following parameters were monitored: methane by gas chromatography; butyrate and acetate by high performance liquid chromatography; oxidation-reduction potential; pH and conductivity. RNA was extracted and taxonomic composition of the microbial communities was obtained by 16S rRNA gene sequencing. Results During the first incubations, AC-enrichment consumed hydrogen derived from butyrate degradation within 4 days, which was much faster than the enrichments with Mag and without CM, which presented lag phases (LP), preceding MP, longer than 11 and 7 days, respectively. Thus, Mag probably inhibited butyrate-degrading bacteria and/or hydrogenotrophic methanogens. Conversely, after the lag phase, Mag-enrichment was the fastest converting acetate to methane (3 times faster than in AC-enrichment), suggesting a stimulatory effect of Mag towards acetoclastic methanogens. Nevertheless, once the enrichments were adapted to the growth conditions, more efficient butyrate conversion was observed by all enrichments, with lag phases lower than 4 days, even in the control-enrichment. No significant changes on butyrate degradation were observed when highly adapted CM-enrichments were transferred to fresh medium without CM. On the other hand, when active enrichments (without previous contact with CM), were incubated with AC, it became slightly faster (0.7 times shorter LP), and with Mag were greatly inhibited (12 times longer LP). Syntrophomonas spp. represented 60 to 80 % of the total bacterial communities in all enrichments. Hydrogenotrophs were more abundant in AC-enrichment (78 % of Methanomicrobiales) and Mag-enrichment was highly enriched in acetoclastic methanogens (43 % of microorganisms assigned to Methanosaeta and Methanosarcina). Conclusions The presence of CM affects the performance of butyrate-degrading communities, with AC accelerating particularly butyrate conversion to methane (via H2/CO2) and acetate, and Mag inhibiting that first step but stimulating acetate conversion to methane.info:eu-repo/semantics/publishedVersio

Comparison of ratioing and RCNA methods in the detection of flooded areas using Sentinel 2 Imagery (case study: Tulun, Russia)

Climate change and natural disasters caused by hydrological, meteorological, and climatic phenomena have a significant impact on cities. Russia, a continental country with a vast territory of complex geographic–ecological environments and highly variable climatic conditions, is subject to substantial and frequent natural disasters. On 29 June 2019, an extreme precipitation event occurred in the city of Tulun in the Irkutsk oblast, Russian Federation, which caused flooding due to the increase in the water level of the Iya River that passes through the city, leaving many infrastructures destroyed and thousands of people affected. This study aims to determine the flooded areas in the city of Tulun based on two change detection methods: Radiometric Rotation Controlled by No-change Axis (RCNA) and Ratioing, using Sentinel 2 images obtained before the event (19 June 2019) and during the flood peak (29 June 2019). The results obtained by the two methodologies were compared through cross-classification, and a 98% similarity was found in the classification of the areas. The study was validated based on photointerpretation of Google Earth images. The methodology presented proved to be useful for the automatic precession of flooded areas in a straightforward, but rigorous, manner. This allows stakeholders to efficiently manage areas that are buffeted by flooding episodes.LA/P/0069/2020info:eu-repo/semantics/publishedVersio