Portuguese science needs a shakeup

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River damming leads to decreased phytoplankton biomass and disappearance of cyanobacteria blooms

The large Alqueva dam was built in the early 2000s in the Guadiana River (southern Portugal) and has highly controlled the freshwater flowing into the Guadiana estuary, leading to significant changes in the natural hydrological regime. To evaluate the impacts of water restriction and flow regularization on estuarine phytoplankton and their environmental variables, sampling campaigns were conducted in the Guadiana estuary throughout a 14-year period, covering different phases related to the Alqueva dam construction. Significant alterations in phytoplankton and their environmental drivers were observed. In the post-filling period, river flow became more constant throughout the year and its natural seasonal variability, with maxima in the winter and minima in the summer, was greatly reduced, leading to higher river flows in the summer and lower in the winter, in relation to the pre-filling phase. Nutrient and light availability and, hence, phytoplankton dynamics, were greatly affected. Phytoplankton abundance and biomass decreased in the post-filling phase related to a decrease in diatoms and cyanobacteria. Since cyanobacteria blooms in the Guadiana are frequently dominated by toxic species, this constitutes an improvement in water quality. However, the overall decrease in phytoplankton biomass and, specifically, the decline in diatom biomass, will have major consequences for the higher trophic levels that depend on planktonic food

Role of microbes in the Ria Formosa lagoon

With the development of epifluorescence microscopy and sensitive radioisotope techniques, high abundance and activity of microorganisms was observed in marine waters since 1970s and 1980s. These observations resulted in a new concept of rapid turn-over and recycling of organic matter through a ‘microbial loop’ (Azam et al., 1983; Azam, 1998). Figure 5.1 illustrates fluxes of material through the marine microbial loop. Main processes are C fixation by photosynthetic microorganisms (prokaryotic and eukaryotic) with exudation losses of Dissolved Organic Matter (DOM), which is incorporated by heterotrophic bacteria. Phagotrophic protists in turn graze both autotrophs and bacteria producing ‘sloppy feeding’ loss of DOM, which returns to the loop. DOM is remineralized by all microorganisms into Dissolved Inorganic Nutrients (DIN), which are taken up by autotrophic and heterotrophic microorganisms.EU contract EVK3-CT1999-00002info:eu-repo/semantics/publishedVersio

SARS-CoV-2 contamination potential in environmental and wastewaters in the Algarve region, Southern Portugal

The Ria Formosa, Southern Portugal (Algarve) is a mesotidal lagoon with restricted exchange with Atlantic Ocean. Due to arid Mediterranean climate and absence of large freshwater inputs, the lagoon remains hypersaline relative to adjacent ocean (>= 37 psu). Generally, fecal coliforms and land-derived bacteria do not survive long in seawater due to UV, osmotic shock, oligotrophy and competition with marine bacteria. However, survival of human pathogenic viruses in natural waters remains relatively unknown. In view of 2020-2021 SARS-CoV-2 pandemic, this preliminary study aimed to estimate potential contamination by wastewater and persistence in marine environment. Five sampling campaigns (45 total samples) were completed in 2020 and 2021 at three stations in the lagoon, as well as inflow and outflow from three wastewater treatment plants (WWTPs). Despite relatively high fecal contamination at lagoon stations, SARS-CoV-2 could not be detected in surface waters using improved methodology. Untreated wastewaters were positive at Faro-Aeroporto 21/10/2020, 14/12/2020, 08/03/2021; Vilamoura 21/10/2020, 14/12/2020; Olhao 14/12/2020. All treated wastewaters were negative, as well as environmental samples. Highest viral titers were observed in Faro-Aeroporto WWTP on 8 March 2021 (1.35 x 10(5) genomic copies L-1) coinciding with peak SARS-CoV-2 cumulative positive cases in Algarve (2.03 x 10(4)), yet SARS-CoV-2 was not detected in Vilamoura and Olhao raw wastewater then. Thus, the contamination potential of SARS-CoV-2 seemed non-existent in the Ria Formosa during peak pandemic surges in Algarve. However, predicted climate change and its impact on microbial populations remains a challenge to be addressed by both health and tourist authorities.info:eu-repo/semantics/publishedVersio

Structural modification of the Pseudomonas aeruginosa alkylquinoline cell–cell communication signal, HHQ, leads to benzofuranoquinolines with anti-virulence behaviour in ESKAPE pathogens

Microbial populations have evolved intricate networks of negotiation and communication through which they can coexist in natural and host ecosystems. The nature of these systems can be complex and they are, for the most part, poorly understood at the polymicrobial level. The Pseudomonas Quinolone Signal (PQS) and its precursor 4- hydroxy- 2-heptylquinoline (HHQ) are signal molecules produced by the important nosocomial pathogen Pseudomonas aeruginosa. They are known to modulate the behaviour of co-colonizing bacterial and fungal pathogens such as Bacillus atropheaus, Candida albicans and Aspergillus fumigatus. While the structural basis for alkyl-quinolone signalling within P. aeruginosa has been studied extensively, less is known about how structural derivatives of these molecules can influ-ence multicellular behaviour and population- level decision-making in other co-colonizing organisms. In this study, we investigated a suite of small molecules derived initially from the HHQ framework, for anti-virulence activity against ESKAPE pathogens, at the species and strain levels. Somewhat surprisingly, with appropriate substitution, loss of the alkyl chain (present in HHQ and PQS) did not result in a loss of activity, presenting a more easily accessible synthetic framework for investigation. Virulence profiling uncovered significant levels of inter-strain variation among the responses of clinical and environmental isolates to small-molecule challenge. While several lead compounds were identified in this study, further work is needed to appreciate the extent of strain- level tolerance to small-molecule anti-infectives among pathogenic organisms.National Forum for the Enhancement of Teaching and Learning in Higher Education SFI/12/IP/1315, US Cystic Fibrosis Foundation SFI/12/RC/2275, National Health and Medical Research Council (NHMRC) of Australia SFI/12/RC/2275_P2, UCC Strategic Research Fund and Science Foundation Ireland (SFI) SSPC-3 12/RC/2275_2, Synthesis and Solid State Pharmaceutical Centre (SSPC) HRB-ILP-POR-2019-004, MRCG-2018-16, Universidade do Algarve TL19UCC1481/02, OGARA1710, APP1183640 2020-5,info:eu-repo/semantics/publishedVersio