Impact of biofilm growth in the microbial community composition of a sequencing batch reactor

Conventional activated sludge wastewater treatment plants (WWTP) for carbon and nutrient removal operate at high sludge retention time and, consequently, at a low food to microorganisms ratio. While the first condition is favourable for nitrifying bacteria growth, an excessive growth of certain species of filamentous bacteria often occurs in the presence of the second one. Interestingly, no problems with excessive growth of filamentous bacteria have been reported for the activated sludge process when combined with biofilm growth more than a decade ago. In this context, the present work aims to compare the microbial community composition of two sequencing batch reactors (SBRs) operating in the presence and in the absence of biofilm growth, and to correlate microbial composition with the performance of the reactors. Two SBRs with a working volume of 1.5 L were operated in parallel with a constant cycle time of 4 h, a volume exchange ratio of 0.5 L/L and a resulting hydraulic retention time of 8 h. The duration of the individual operating phases was: 5 min fill, 225 min aerated, 5 min settle and 5 min draw. During the aerated phase airflow was applied through membrane diffusers, causing the reactor contents including the carrier bed to circulate. The SBRs were operated with synthetic water containing acetate as the only carbon source and ammonium as nitrogen source. One SBR was operated just with suspended biomass while the second one combined suspended biomass with biofilm cultivation. The biofilm was formed on a new type of polyethylene support developed by University of Minho, consisting of hollow, star-shaped, carriers with 17 mm external diameter and a height of 10 mm. The bed formed by these carriers had a specific surface area of 407 m2/m3, an average porosity of 0.74 and occupied 20 % of the reactor volume. Grab samples were taken and analyzed for acetate using a HPLC system. Observation of the filamentous microbial and microfauna communities was accomplished by microscope inspection at 100 to 1000X magnification, in fresh samples and after Gram and Neisser staining. The microbial community of the SBR operating just with suspended growth was dominated by fungi micelar growth, while in the other reactor the communities were clearly more complex. The incorporation of carriers for biofilm growth in the other SBR apparently suppressed the excessive growth of fungi. Differences in the microfaunas community were also observed, the SBR operating just with suspended growth showing clearly a delay in the microfauna succession comparing to the other reactor. Despite this, acetate was completely removed in both SBRs

Crescimento e actividade fetal às 20-24 semanas de gestação (estudo preliminar)

Evidências empíricas recentes mostram que o desenvolvimento psicológico se inicia muito antes da nascença e que condições pré-natais podem explicar uma parte significativa da futura variabilidade comportamental e desenvolvimental da crian-ça. Objectivos: O objectivo deste estudo foi caracterizar o desenvolvimento fetal entre as 20 e as 24 semanas de gestação, no que se refere a indicadores de crescimento fetal – distância biparietal, perímetro abdominal, perímetro cefálico, comprimento do fémur e peso fetal estimado – e a indicadores de actividade fetal – batimentos cardíacos e movimentais fetais. Visou, ainda, estabelecer possíveis diferenças em cada uma destas medidas, tendo em conta variáveis sócio-demográficas da mãe e do bebé, bem como condições obstétricas e consumo de substâncias na actual gravidez. Método: A amostra deste estudo englobou 48 fetos (52.1% do sexo feminino e 47.9% do sexo masculino), com uma idade gestacional estimada (GA) compreendida entre as 20-24 semanas (média = 21 semanas e 1 dia), cujas mães eram utentes da Consulta Externa de Ginecologia/Obstetrícia da Maternidade de Júlio Dinis (Porto). Foi efectuado um registo em vídeo do comportamento fetal e recolhidas as medidas biométricas correspondentes à ecografia morfológica. Resultados: A análise estatística dos dados mostrou, após controlada a idade gestacional, diferenças nas medidas de crescimento fetal tendo em conta a ocupação [F(1,41) = 7.28; p = .000], o estado civil [F(1,41) = 2.61; p = .04], o agregado familiar [F(1,41) = 2.91; p = .03] e o consumo de café [F(1,40) = 2.55; p = .05] por parte da mãe. Diferenças nas medidas da actividade fetal (batimentos cardíacos) foram também observadas para a variável sexo do bebé [F(1,16) = 5.84; p = .009]. Conclusão: Conclui-se quanto à sensibilidade do desenvolvimento fetal a factores relacionados com as características sócio-demográficas maternas e fetais e o consumo de substâncias por parte da mãe durante a gestação.Esta investigação foi financiada pela Fundação para a Ciência e a Tecnologia, no âmbito do projecto FCT-POCTI/SAUESP, 56397/2004 e da Bolsa de Doutoramento SFRH/BD/13768/200

Towards efficient ciprofloxacin adsorption using magnetic hybrid nanoparticles prepared with κ-, ι-, and λ-carrageenan

The efficient removal of the antibiotic ciprofloxacin (CIP) from aqueous samples using magnetic nanosorbents prepared using three sulfated polysaccharides, κ-, ι- and λ-carrageenan and an alkoxysilane agent containing a reactive epoxide ring is described. The prepared nanosorbents were characterized in detail using FTIR spectroscopy, solid-state 29Si and 13C NMR spectroscopy and elemental microanalysis. The synthesis method was more effective for incorporating higher amounts of κ-carrageenan in the siliceous shells. Although being less sulfated, κ-carrageenan is cheaper than the other carrageenan tested. The CIP adsorption was a cooperative process, well described by the Dubinin–Radushkevich isotherm, with maximum adsorption capacities of 878, 969 and 865 mg/g for κ-, ι- and λ-carrageenan sorbents, respectively. Overall, the produced magnetic nanosorbents are among the best magnetic systems with high adsorptive efficiency for CIP. It is suggested that protonated CIP molecules are exchanged with ester sulfate counterions of carrageenan at the particles’ surface as the main pathway for CIP adsorption. The adsorption process was exothermic and entropically favorable for the three sorbents. However, at 298 K, the adsorption was spontaneous for κ-carrageenan-based sorbents and non-spontaneous for ι- and λ-carrageenan particles. The magnetic sorbents could be reused and maintained their ability towards CIP removal up to four cycles. The removal efficiency in wastewater was enhanced with the sorbent dose. Graphical abstract: [Figure not available: see fulltext.] Magnetic carrageenan nanosorbents were prepared using three carrageenan polysaccharides (κ-, ι-, and λ-carrageenan). The resulting magnetic particles removed the antibiotic ciprofloxacin efficiently from ultra-pure water and wastewater samples. Magnetic features enabled the fast magnetic separation of the nanosorbents from water.publishe

The Social Distancing Imposed To Contain COVID-19 Can Affect Our Microbiome: a Double-Edged Sword in Human Health

Hygienic measures imposed to control the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and contain COVID-19 have proven effective in controlling the pandemic. In this article, we argue that these measures could impact the human microbiome in two different and disparate ways, acting as a double-edged sword in human health. New lines of research have shown that the diversity of human intestinal and oropharyngeal microbiomes can shape pulmonary viral infection progression. Here, we suggest that the disruption in microbial sharing, as it is associated with dysbiosis (loss of bacterial diversity associated with an imbalance of the microbiota with deleterious consequences for the host), may worsen the prognosis of COVID-19 disease. In addition, social detachment can also decrease the rate of transmission of antibiotic-resistant bacteria. Therefore, it seems crucial to perform new studies combining the pandemic control of COVID-19 with the diversity of the human microbiome.info:eu-repo/semantics/publishedVersio

Pesquisa de leucócitos residuais

A presença de leucócitos nos concentrados de eritrócitos (CE) e nos concentrados de plaquetas (CP) está associada a uma maior incidência de reacções febris, com transmissão de citomegalovírus (CMV) e aloimunização a antigénios HLA em indivíduos transfundidos. A exigência de componentes sanguíneos pobres em leucócitos implica a existência de um controlo relativamente à persistência dos leucócitos residuais. As amostras foram adquiridas no citómetro de fluxo e analisadas mediante um programa informático. A citometria de fluxo permite quantificar os leucócitos residuais dos diferentes componentes sanguíneos, avaliando a conformidade ou não conformidade com as normas exigidas pelo conselho da Europa

Estuarine Aquacultures at the Crossroads of Animal Production and Antibacterial Resistance: A Metagenomic Approach to the Resistome

It is recognized that the spread of antibiotic resistance (AR) genes among aquatic environments, including aquaculture and the human environment, can have detrimental effects on human and animal health and the ecosystem. Thus, when transmitted to the human microbiome or pathogens, resistance genes risk human health by compromising the eventual treatment of infections with antibiotic therapy. This study aimed to define the resistance profile of aquaculture farms and their potential risk for spreading. Twenty-four sediments from oyster and gilthead sea bream aquaculture farms located in three Portuguese river estuaries (17 sediments from Sado, 4 from Aveiro, and 3 from Lima) were studied by comparative metagenomic analysis. The computation of the diversity of genes conferring resistance per antibiotic class revealed a significant increase in aminoglycosides, beta-lactams, disinfectants, quinolones, and tetracyclines counts. In all geographic locations under study, the most diverse AR genes confer resistance to the macrolides, tetracyclines and oxazolidinones classes, all of which are medically important for human and animal therapies, as well as resistance to disinfectants. The diversity of mobile genetic elements correlated with the number of AR genes such as tetracyclines, suggesting that AR could be easily mobilized among bacterial genomes and microbiomes.info:eu-repo/semantics/publishedVersio

Qualidade físico-química e microbiológica da água de piscinas do distrito de Bragança

A piscina é utilizada para fins recreativos, formativos, terapêuticos ou desportivos e de forma a impedir que a sua água seja um veiculo de infeções é importante a sua desinfeção. Por conseguinte, os utilizadores de piscinas e os vários grupos profissionais que aí desempenham atividades podem estar sujeitos a diversos perigos, nomeadamente biológicos e químicos. A contaminação biológica relaciona-se com o desenvolvimento de diferentes microrganismos onde se pode distinguir os de origem fecal e origem não-fecal. Quanto aos perigos químicos, estes estão relacionados principalmente com a exposição a substâncias químicas tóxicas presentes na água

Separation of non-ferrous frations of shredded end-of-life vehicles for valorising its alloys

Worldwide the end-of-life vehicles (ELV) generate millions of tons of waste, requiring an adequate and efficient management. The non-ferrous fraction contains essentially aluminium, magnesium and copper alloys, being valorised by metallurgical processors to obtain new metals and alloys. However most of the recovered metals are downcycled, as is the case of aluminium where the recycled products are essentially used to produce less purity casting alloys. New or improved separation technologies are therefore necessary in order to allow an accurate separation of alloys or alloy groups, increasing the value of the non-ferrous streams. In this paper, the composition of the non-ferrous fractions of ELV shredders are assessed with particular relevance for the aluminium and magnesium alloys. Essentially, the main cast and wrought alloys are characterized and their markets and applications are discussed. Based on waste composition, several physical separation and sorting technologies can be applied to improve the products quality, which are here depicted and discussed. Physical processing includes operations such as eddy current and heavy media separations. For sorting alloys contained in the non-ferrous stream, other sensor-based technologies are being developed, such as electromagnetic sensing and novel laser induced breakdown spectroscopy systems, constituting an important contribution for boosting the non-ferrous metals recycling rates

Assessment of iron and nitrates concentration in drinking water, in the district of Bragança, Portugal between 2012 and 2013

Water is an essential resource for life. It is a crucial factor for all living beings’ survival thus, it is necessary to promote means to obtain drinking water for human consumption.1 The water intended for human consumption, according to the World Health Organization (WHO),is quality water as soon as it does not cause a significant threat to human health during its consumption.2 The diseases related to the contamination of water for human consumption constitute a very high responsibility and importance to the Public Health. The nitrates have a high solubility and may reach the groundwater in the deep layers of the soil by processes as leaching, particularly in areas with intensive farming and livestock. High concentrations of nitrates can be very harmful to human health since they can be easily converted into nitrites which concentrations cannot exceed the parametric value of 50 mg/L in water for human consumption (Dec. Law n.º 306/2007). The greater effect of nitrite in human health is your involvement in the oxidation of hemoglobin (Hb) to methemoglobin (MetHb). High concentrations of nitrates cause severe methaemoglobinemia in infants and adults. The methemoglobinemia is a rare condition caused by excessive conversion of hemoglobin (Hb) in methemoglobin (MetHb), being unable to bind and transport oxygen.3The iron exists in low concentrations in natural waters and usually its presence results of processes such as leaching of soils or industrial pollution. The presence of iron in the water can consequently cause the corrosion of metal pipes or the use of iron salts as agents of coagulation/flocculation in water treatment and the parametric value of iron is 200μg/L (Dec. Law n.º 306/2007) in water for human consumption.The objective of this study was to evaluate the concentration of nitrate and iron in drinking water in the district of Bragança in order to identify the sampling point that keeps concentrations of these ions above the parametric values.The collection of drinking water samples in the district of Bragança occurred between the years of 2012 and 2013, with subsequent spectrophotometric determination of nitrate and iron concentration, in the Public Health Laboratory of Bragança (PHLB).Samples with concentrations above the parametric values were identified: above 200 μg/L to iron and above 50 mg/L to nitrates (Dec, Law n.º 306/2007). The collected data was statistically treated in program Microsoft Office - Excel and the analysis of the data was carried out using the normal distribution with levels of confidence of 95 %. In the year 2012 were collected 624 samples and 8.8% of these were outside the parametric values with 8.7% corresponding to samples with values of increased iron and 0.1% corresponding to increased nitrate’s values. In the year 2013 it was collected 1208 samples in which 8.9% were above the parametric values stipulated, from which 8.6% corresponded to samples with increased concentrations of iron and 0.3% corresponded to samples with nitrate levels above the parametric values. Two regions exhibited a greater number of samples with concentrations above the established limits for the parameters studied in this work. One of the regions had 15.9% of the samples above the established limits and the other had 12.6%.Individuals that consumed this water with high levels of iron and nitrates may be associated with several potential health threat