97 research outputs found
Iron compounds in anaerobic degradation of petroleum hydrocarbons: a review
Waste and wastewater containing hydrocarbons are produced worldwide by various oil-based industries, whose activities also contribute to the occurrence of oil spills throughout the globe, causing severe environmental contamination. Anaerobic microorganisms with the ability to biodegrade petroleum hydrocarbons are important in the treatment of contaminated matrices, both in situ in deep subsurfaces, or ex situ in bioreactors. In the latter, part of the energetic value of these compounds can be recovered in the form of biogas. Anaerobic degradation of petroleum hydrocarbons can be improved by various iron compounds, but different iron species exert distinct effects. For example, Fe(III) can be used as an electron acceptor in microbial hydrocarbon degradation, zero-valent iron can donate electrons for enhanced methanogenesis, and conductive iron oxides may facilitate electron transfers in methanogenic processes. Iron compounds can also act as hydrocarbon adsorbents, or be involved in secondary abiotic reactions, overall promoting hydrocarbon biodegradation. These multiple roles of iron are comprehensively reviewed in this paper and linked to key functional microorganisms involved in these processes, to the underlying mechanisms, and to the main influential factors. Recent research progress, future perspectives, and remaining challenges on the application of iron-assisted anaerobic hydrocarbon degradation are highlighted.This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of project MORE (POCI-01-0145-FEDER-016575) and of the strategic funding of UIDB/04469/2020 unit. It was also funded by LABBELS—Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020, and by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte—BioEcoNorte project (NORTE-01-0145-FEDER-000070).info:eu-repo/semantics/publishedVersio
Caracóis endémicos dos Açores : estivação como mecanismo de resposta aos fatores ambientais
A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.[…]
Estudos realizados sobre caracóis terrestres endémicos dos Açores têm revelado que estes, ao contrário do observado noutras espécies de moluscos da América do Sul e do Norte, tem a capacidade de se reproduzir durante todo o ano, o que tem sido atribuído a características climáticas propicias verificadas no arquipélago, em termos de temperatura, precipitação ou humidade do solo.
A montanha do Pico (Ilha do Pico) é o melhor “laboratório” dos Açores para avaliar como fatores abióticos, que variam ao longo de um gradiente altitudinal, podem desencadear respostas fisiológicas e comportamentais numa espécie, com significado na sua reprodução e sobrevivência.
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Leaf age, seasonal and annual variations in Salvia officinalis L. var. purpurascens biochemical characteristics
Medicinal and aromatic plants (MAP’s) have gain new attention in the past years due to their content in bioactive compounds and recognized health-promoting effects. One of the most important species of MAP’s is Salvia officinalis L., rich in several phytochemicals (essential oil, phenolic compounds) and vitamins. Besides, it has various uses and pharmacological effects (including antibacterial, antiviral, antioxidative, anti-inflammatory, antidiabetic and antitumour activities). Salvia officinalis L. has many cultivars, including Salvia officinalis L. var. purpurascens, which is currently understudied. As few is known about this specific cultivar, characterization of this plant, as well as the study of biochemical variations occurring during its development, is of great significance. Hence, in this work, young and adult leaves of Salvia officinalis L. var. purpurascens, were collected in two different seasons (June and September) and in two different years (2011 and 2013). Several biochemical traits were analyzed, namely carbohydrate content, photosynthetic pigments concentration, total phenolics, soluble proteins, as well as oxidation parameters (thiobarbituric acid reactive substances, thiols and electrolyte leakage). The Year factor significantly influenced carbohydrate content (higher in 2013 for non-structural carbohydrates and soluble sugars, but lower for starch), but also chlorophyll and carotenoid content (higher in 2011), with a similar influence recorded for the Season of harvest (higher values for starch, chlorophyll and carotenoids in September, but lower for soluble sugars). The developmental stage of leaves showed significant influence mainly in the content of photosynthetic pigments, with higher values of chlorophyll and carotenoids recorded in young leaves. The results show the biochemical variations occurring in plants of Salvia officinalis L. var. purpurascens, during developmental stages, and others associated to season of harvest and year, and their relation to climatic factors. The gathered data, besides useful for the characterization of this plant, is also valuable when aiming for the optimization of sage cultivation
Accounting and the social role of Hospital S. Marcos da Santa Casa da Misericórdia de Braga (Portugal, 1910-1920)
Firmly set in the archive, this study aims at understanding the accounting and social role of the Hospital of S. Marcos da Misericordia in Braga. This study is intended to answer the following question: how does the accounting of the Hospital of S. Marcos da Misericordia in Braga reflect the social, economic and political changes observed during the second decade of the 20th century.
Different archives have been analysed, focusing on the records from the Braga District and from the Santa Casa da Misericordia in Braga. This study allows an understanding of how changes in the management and accounting of the Misericordia and Hospital of S. Marcos determine and are determined by the environment.
This study demonstrates that the Misericordia and the S. Marcos Hospital played a significant social role and were able to adapt to times of crisis, helping to understand how these charities and not-for profit organisations adjust over time in the achievement of their mission
Agaricus Albertii as a source of bioactive compounds: comparison between Portuguese and Serbian species
Mushrooms are widely appreciated all over the world for their nutritional [1] and bioactive
properties, being a source of antioxidant compounds [2]. Its consumption has increased over the
last years and, due to the increased information available related to edible mushrooms, even rare
species started to be an option as food. In this work, the chemical characterization and the
antioxidant properties of Agaricus albertii Bon., collected in Portugal and Serbia, were evaluated
and compared. The individual profiles of organic acids and phenolic compounds were obtained by
UFLC-PDA; tocopherols and free sugars were characterized by HPLC-fluorescence and HPLCRI
, respectively, and the fatty acids profile was obtained by GC-FID. The antioxidant properties
were assessed through the evaluation of the reducing power, radical scavenging activity and lipid
peroxidation inhibition of the samples. The Serbian sample revealed the highest levels of total
organic acids {5.14 g/1 00 g dry weight) while the Portuguese one gave the highest content in
phenolic acids (11.76 mg/1 00 g). In this sample, it was not possible to identify tocopherols.
Rhamnose was only found in A. albertii from Serbia (2.65 g/1 00 g), while fructose was only found
in the Portuguese sample (0.48 g/1 00 g). Mannitol and trehalose were quantified in both samples.
Polyunsaturated fatty acids predominated over mono- and saturated fatty acids. Generally, the
sample from Serbia revealed the highest antioxidant potential, with the highest reducing power,
radical scavenging activity and lipid peroxidation inhibition evaluated through the β~carotene/
linoleate assay. This work is the result of a cooperation between Portugal and Serbia,
allowing a comparative study within the same species from different origins.FCT (Portugal) and COMPETE/QREN/EU for financial support through research project
PTDC/AGR-ALI/11 0062/2009, PEst-OE/AGR/UI0690/2011 CIMO strategic project and L. Barros
grant (SFRH/BPD/4609/2008), and to Serbian Ministry of Education and Science for financial
support (grant number 173032)
Reproductive biology of Oxychilus(Atlantoxychilus) spectabilis (Milne-Edwards, 1885) (Gastropoda: Pulmonata) : a gametogenic approach
The taxonomic status and anatomy of Oxychilus (Atlantoxychilus) spectabilis (Milne-Edwards, 1885), an endemic land snail from Santa Maria Island, Azores, has been subject of detailed study, yet information about its life history is wanting. This study describes the reproductive cycle of O. (A.) spectabilis and assesses the validity of three morphometric shell parameters as maturation diagnostic characters. Our results indicate that individuals are reproductively more active from May to November. However, the availability of spermatozoa throughout the year and the residual values of mature oocytes during the remaining months seem to provide minimum conditions for reproduction all year round. The snail has a functional protandric tendency and gonadal maturation is initially triggered by photophase and after regulated by temperature. The positive correlation between gonadal maturation and morphometric shell characters indicate that these parameters might be a useful tool for the diagnosis of snail’s maturation
Anaerobic biological removal of pharmaceuticals: impact of these micropollutants towards different microbial groups in anaerobic communities
Pharmaceutical compounds are originated essentially from anthropogenic activities and end
up in wastewater treatment plants (WWTP). Despite the low concentrations usually detected
in wastewater (ranging from ng L-1 to g L-1), levels of mg L-1 have been detected in some
countries. Moreover, in conventional WWTP these compounds are hardly degraded and tend
to accumulate in sludge, being an environmental and public health problem.
A possible treatment and valorization of contaminated sewage sludge is through anaerobic digestion, but for that purpose, the effect of these micropollutants on the activity of crucial microbial groups present in the anaerobic sludge (i.e., acetogenic and methanogenic microorganisms) must be assessed.
In this work, the effect of ciprofloxacin (CIP), ibuprofen (IBP), diclofenac (DCF), and 17-ethinylestradiol (EE2), on the activity of acetogenic and methanogenic anaerobic communities was investigated1. The microorganisms respond dissimilarly to these micropollutants, at
different concentrations (0.01-100 mg L-1), but in general they were more affected by CIP,
followed by EE2, DCF and IBP. The specific methanogenic activity (SMA) was not affected in
concentrations ranging from 0.01 to 0.1 mg L-1. However, acetoclastic methanogens were the
most sensitive microorganisms, being affect by all the pharmaceuticals, at higher
concentrations. The SMA of these microorganisms was inhibited 20% by 1 mg L-1 of CIP, and
circa 50% with higher concentrations. Acetogenic bacteria were not affected by IBP at all the
tested concentrations, but they were sensitive to CIP at concentrations above 1 mg L-1, and to
DCF and EE2 at concentrations above 10 mg L-1. Instead, hydrogenotrophic methanogens
were not affected by any concentration, indicating their lower sensitivity.
It can be concluded that methanogenic communities were not severely affected by these
pharmaceuticals. So, the application of anaerobic digestion for the treatment of wastewater
and sewage sludge contaminated with pharmaceuticals seems promising. Indeed, another
study showed that CIP can be removed by anaerobic sludge in the presence of carbon
materials (99% removal), and treated wastewater was much less toxic than before the
treatment (46% detoxification), as assessed with the standard bioassay using Vibrio fischeri.info:eu-repo/semantics/publishedVersio
Corksorb enhances alkane degradation by hydrocarbonoclastic bacteria
Biosorbent materials are effective in the removal of spilled oil from water, but their effect on hydrocarbonoclastic bacteria is not known. Here, we show that corksorb, a cork-based biosorbent, enhances growth and alkane degradation by Rhodococcus opacus B4 (Ro) and Alcanivorax borkumensis SK2 (Ab). Ro and Ab degraded 96 ± 1% and 72 ± 2%, respectively, of a mixture of n-alkanes (2 g L1) in the presence of corksorb. These values represent an increase of 6 and 24%, respectively, relative to the assays without corksorb. The biosorbent also increased the growth of Ab by 51%. However, no significant changes were detected in the expression of genes involved in alkane uptake and degradation in the presence of corksorb relative to the control without the biosorbent. Nevertheless, transcriptomics analysis revealed an increased expression of rRNA and tRNA coding genes, which confirms the higher metabolic activity of Ab in the presence of corksorb. The effect of corksorb is not related to the release of soluble stimulating compounds, but rather to the presence of the biosorbent, which was shown to be essential. Indeed, scanning electron microscopy images and downregulation of pili formation coding genes, which are involved in cell mobility, suggest that cell attachment on corksorb is a determinant for the improved activity. Furthermore, the existence of native alkane-degrading bacteria in corksorb was revealed, which may assist in situ bioremediation. Hence, the use of corksorb in marine oil spills may induce a combined effect of sorption and stimulated biodegradation, with high potential for enhancing in situ bioremediation processes. © Copyright © 2021 Martins, Freitas, Castro, Silva, Gudiña, Sequeira, Salvador, Pereira and Cavaleiro.This study was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of
project MORE (POCI-01-0145-FEDER-016575) and Salt Oil+ (POCI-01-0145-FEDER-030180) and of the strategic funding of UIDB/04469/2020 unit. Research of RS and JS was supported by Ph.D. grants SFRH/BD/116154/2016 and SFRH/BD/147271/2019, respectively, funded by FCT.info:eu-repo/semantics/publishedVersio
Can Suillus granulatus (L.) Roussel be classified as a functional food?
The present work outlines a detailed chemical characterization of Suillus granulatus species, besides the antioxidant and antimicrobial properties of their methanolic extracts. The study was carried out with samples drawn from Portugal and Serbia in order to prove that though mushrooms are strongly influenced by the environment in which they develop, they have a specific chemical profile that can be typical of their genus/species. The studied species proved to be healthy foods, low in fat and rich in protein and carbohydrates, with mannitol and trehalose being the main free sugars detected. They also proved to be a source of organic and phenolic acids, as well as mono- and polyunsaturated fatty acids and tocopherols. The Serbian samples revealed higher antioxidant and antimicrobial potential. Accordingly, we find that the S. granulatus species is likely to be considered a functional food, since it is a source of nutraceutical and biologically active compounds.The authors are grateful to Foundation for Science and Technology (FCT, Portugal) and COMPETE/QREN/EU for the financial support of the CIMO strategic project PEst-OE/AGR/UI0690/2011 and of the contract of L. Barros. The authors also thank to the Serbian Ministry of Education, Science and Technological Development for financial support (grant number 173032). The authors thank Dr. Maria João Sousa for the harvest of the Portuguese samples
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