CH4 production at moderate H2/CO2 pressures insights on the use of anaerobic granular sludge as biocatalyst

Introduction: The continuous increase in energy consumption and the intensive use of fossil fuels, lead to the emission of greenhouse gases (GHG) and, in particular, to an increase in the concentration of CO2 in the atmosphere. In this context, the improvement in global awareness and the demand for sustainable technologies and products strongly contribute to laid plans to combat climate change. CO2-to-CH4 conversion represents a cutting-edge solution for CO2 capture and use, contributing to the reduction of GHG emission. Catalytic conversion of CO2-to-CH4 have been investigated, however, the high cost associated to the catalysts employed limits their use on a large scale. Biological CO2 methanation can overcome the significant technical and economic challenges of catalytic CO2 methanation. The biological production of CH4 using CO2-rich gases together with H2 is a promising strategy for the production of bioproducts. Hydrogenotrophic methanogens have a crucial role on the direct conversion of CO2+H2 into CH4, hence the importance to study the specific hydrogenotrophic methanogenic activity (SHMA). Methodology: In this work, the effect of initial substrate (H2/CO2) pressure, from 100 to 500 kPa, on the SHMA, on CH4 production rate and on developed microbial communities were evaluated. Two different pressurized bioreactors were studied using anaerobic granular sludge as the biocatalyst and H2/CO2 (80:20, v/v) as sole carbon and energy source. Gaseous compounds were analyzed by GC and archaeal diversity within granular sludge was monitored by 16S r-RNA based techniques. Results: The results showed an increase in the SHMA as well as in the CH4 production rate with the increase of the initial H2/CO2 pressure. This results are very interesting since no inhibitory effects were observed on the microbial activity, demonstrating the resistance of the anaerobic granular sludge. The Illumina results showed that Methanosarcinales, Methanobacteriales and Methanomicrobiales were the three orders that prevailed in the pressurized system, for all the pressures tested. However, hydrogenotrophic methanogens from Methanobacterium and Methanospirillum genera slightly increased their relative abundance, varying from 38% (100 kPa) to 41% (500 kPa) and from 8% (100 kPa) to 12% (500 kPa), respectively. Conclusions: In conclusion, the archaeal community seems to be very stable when submitted to increasing H2/CO2 pressures, highlighting the potential of the anaerobic granular sludge as an efficient microbial platform for the production of added-value compounds from gaseous carbon waste streams.Portuguese Foundation for Science and Technology (FCT): POCI-01-0145-FEDER-031377; strategic funding of UIDB/04469/2020 unit; BioTecNorte operation (NORTE-01-0145-FEDER-000004); FCT doctoral grant PD/BD/128030/2016.info:eu-repo/semantics/publishedVersio

CH4 production at moderate H2/CO2 pressures - insights on the specific hydrogenotrophic methanogenic activity

CO2 is one of the main contributors to greenhouse gases (GHGs), being its emission to the atmosphere one of the major driver of global climate change. Biological methanation of CO2 using renewable H2 provides a promising approach to use of superplus renewable electrical power to produce a gaseous fuel. CH4 is considered an important renewable energy carrier, that has a wide range of applications such as natural gas for distribution. Hydrogenotrophic methanogens are key elements in the CO2/H2 methanation process. Thus the importance to study the specific hydrogenotrophic methanogenic activity (SHMA). The effect of the initial substrate (H2/CO2) pressure on the SHMA was investigated in two different pressurized bioreactors. The results suggest that in addition to the increase of the initial substrate pressure, also the bioreactor configuration influence the SHMA, which is crucial for the success of biological CO2 methanation technologies but also in anaerobic bioreactors treating wastewaters.info:eu-repo/semantics/publishedVersio

Hydrogenotrophic activity under increased H₂/CO₂ pressure: effect on methane production and microbial community

H2 and CO2 are main compounds of synthesis gas. Efficient conversion of syngas to biomethane is a straightforward strategy to integrate the energy value of syngas into existing natural gas grid infrastructures. In this study, the effect of initial H2/CO2 (80/20, v/v) pressure on methane production rate and microbial community diversity was assessed in a hyperbaric bioreactor inoculated with anaerobic granular sludge. Several batch experiments were performed to distinguish between the effect of initial total gas pressure and H2/CO2 partial pressure: (1) varying initial gas pressure (from 1 to 6 bar) with 100% H2/CO2 mixture; (2) constant initial gas pressure (5 bar), with increasing H2/CO2 partial pressure (from 1 to 5 bar); (3) varying initial gas pressure (from 2 to 5 bar) with constant H2/CO2 partial pressure (2 bar). In (2) and (3), N2 was used for ensuring the necessary overpressure. Microbial community changes in the system were monitored by 16S rRNA-based techniques (PCR-DGGE). The raise of H2/CO2 initial pressure (100% H2/CO2) from 1 to 5 bar led to an improvement in methane rate production from 0.035 ± 0.014 mmol h1 to 0.072 ± 0.019 mmol h1. Similar methane production rates were observed in reactors operated at the same H2/CO2 partial pressures, even when varying the total initial gas pressure. Hydrogen partial pressure was shown to determine the structure of bacterial communities and diversity decreased with increasing H2/CO2 partial pressure. No significant changes were observed for the archaeal communities

Ecophysiological potential of the Dão terroir for the production of Touriga Nacional red grapes

Proceedings - IX International Terroir Congress, 2012Aiming to evaluate the potential of the portuguese Dão winegrowing region for the production of Touriga Nacional (TN) red grapes, climatic, ecophysiological and viticultural data from two different climatic years (2004, wet year and 2005, dry year) are presented and discussed. The data was collected in the control non-irrigated plants of an irrigation experiment installed at the Dão Research Station, Nelas, Portugal. The vineyard is established in a typical granitic soil and trained on a vertical shoot positioning. According to the Géoviticulture Multicriteria Climatic Classification System, the Dão region is classified as temperate/temperate warm for the heliothermal index, with cool nights (night cold index) and moderately dry (dryness index). In 2004 the predawn leaf water potential presented always values higher than -0.2 MPa from flowering to harvest but in 2005 moderate to severe water stress was observed during the ripening period (-0.4 MPa at veraison to -0.6 MPa at harvest). Leaf stomatal conductance and photosynthetic rate displayed a decreasing pattern from flowering to harvest in both years but attained much lower values in the 2005 ripening period as compared to that of 2004. The yield was similar in both years but 2005 showed lower sugar content, similar titratable acidity and a higher anthocyanin berry skin content. Our data shows that the Dão terroir presents a high inter-annual climate variability which has important repercussions on TN responses being the most unfavorable climatic years those were the high temperatures are coincident with water stress during the first half of the ripening period. In those years irrigation should be applied in order to obtain better quality grapes

Effects of the use of active video games in balance and quality of life: systematic review

Introduction: In the past few years the interest about information and communication technologies has grown. Considering that the use of exergames is increasing, arousing the interest of the scientific community because of their innovative intervention’s strategies, it was considered important to study the effectiveness of it´s use in some aspects like balance and quality of live. Objective: To study (what is) the effectiveness of exergames intervention programs on outcomes like balance and quality of life along the life cycle. Methodology: The research was performed in the following databases: PUBMED, IEEE Xplore Database, CochraneLibrary, Cochrane Central Register of Controlled Trials (Clinical Trials) and Health Technology Assessment Database (Technology Assessments)), EBSCO, PEDro, ACM the guide, Elsevier, Springer and Taylor & Francis. The selected search terms were video games, gaming, active video games, wii, Xbox, exergame, postural balance, quality of life. Different research’s equations were used with the following inclusion criteria: RCT studies in English, Spanish or Portuguese language, it couldn’t be studies accomplished before 2001 including that year. According to the criteria and the application of PEDro scale, 5 articles comprised the analyzed final sample after selection. Results: There is no consensus among the studies which were analyzed as to the true relation between balance gains and the utilization of the different exergames. However that relation has been verified in the outcome quality of life. In this second outcome it was considered the increasing on the motivation levels and interest in therapy. Those contribute to a better adhesion in the therapeutic treatment and consequently to functional gains. Conclusion: According to the reviewed studies in this systematic review, it was possible to verify that the utilization of game consoles may be recommended as an instrument to the rehabilitation of patients who have disturbance in balance and decreased levels of quality of life, since the feedback’s system promotes motor control and motor learning. This systematic review has a strong impact in Physiotherapy practice because it allows the comprehension of what studies were performed in the area so far, whereas the utilization of those instruments implies, as all the Physiotherapy interventions, better scientific evidence.N/

Knowledge and attitude towards the gradual reduction of salt in bread – an online survey

Aim: Assess knowledge and attitude towards the gradual reduction of salt in bread and the potential impact on eating habits of children (6-18 years) and their families, as part as a Health Impact Assessment pilot study.N/

Pressurized syngas bioconversion: physiological and microbial characterization

ICBM-3 - 3rd International Conference on Biogas MicrobiologySyngas is composed mainly by CO, H2 and CO2 and its fermentation is a promising biological process to produce fuels or commodity chemicals. Experiments under increased initial syngas pressures, up to 5.2×105 Pa, were carried out to evaluate the effects on metabolites production and microbial communities structure. Two strategies were applied: NB non-adapted biomass and SB successively syngas-fed biomass. The rise of syngas pressure from 1.2×105 Pa up to 5.2×105 Pa led to a decrease on CO and H2 consumption rates and CH4 production rate. Moreover, when methanogenesis was partially inhibited, propionate and butyrate were the main metabolites produced from syngas. DGGE profiles showed differences on diversity and on similarity indices (SI) with changes in pressure. Regardless the syngas pressure employed, the archaeal communities had higher SI (above 70%) than bacterial community (48% to 62%). From the Illumina sequencing analysis, it was observed that the relative abundance of bacterial communities tend to decrease (72% to 46%), and archaeal communities increased (25% to 54%) by raising the pressure of syngas from 1.2×105 Pa to 5.2×105 Pa. In the inoculum and biomass incubated at 1.2×105 Pa syngas, 40% of total population were from Proteobacteria phylum and Deltraproteobacteria class and their abundance was reduced 4-fold at 5.2×105 Pa. As a direct effect of high pressures of syngas, organisms belonging to Firmicutes, Synergistetes and Thermotogae phyla increased over 10-fold. The predominant phylotypes at 3×105 Pa and 5.2×105 Pa were related to Methanobacterium genus (archaea) and to Eubacteriaceae, Synergistaceae and Syntrophobacteraceae families (bacteria). These results showed a microbial population enrichment suggesting a high specialization for the substrate.info:eu-repo/semantics/publishedVersio

Effects of irrigation on the vigour, yield and berry composition of the red variety Touriga Nacional at the Dão winegrowing region, Portugal

Proceedings - 17 th International Symposium GIESCO, Asti, Italy, 2011In a field trial installed at the Centro de Estudos Vitivinícolas do Dão, Nelas, Portugal, the effect of three irrigation treatments on the agronomic behaviour of cv Touriga Nacional (Vitis vinifera L.) were studied during three growing seasons (2006-2008). Three irrigation treatments (DI30 - irrigation with 30% of ETc; DI50 - irrigation with 50% ETc, FI - full irrigation – 100% Etc) were compared to a control non-irrigated treatment (NI). Compared to NI, the deficit irrigation treatments (DI30 & DI50) showed no significant differences on the yield and its components. The full irrigation treatment induced a significantly higher yield due to a higher bunch weight, as compared with the others treatments. Compared to the control, the deficit irrigation treatments presented similar berry composition during all the three seasons. The FI treatment presented, in all seasons, a significantly higher total acidity and a significantly lower Brix and total anthocyanins concentration as compared to the other treatments. The pruning weight and shoot weight increased with the amount of irrigation water applied, but significant differences were found only between the FI and the NI treatments, the last presenting the lowest values. Despite the fact that in the non-irrigated vineyards of the Dão winegrowing region it is very common to observe vine water stress symptoms, mainly during the ripening period, during the three studied seasons (2006-2008), the deficit irrigation treatments showed no advantages relatively to the control non-irrigated. Despite the higher yield produced in the full irrigation, this treatment had the disadvantages of the excessive vine vigour and lower must quality produced

Daily evolution of the components of the balance of radiation of vines in a vineyard in the Dão region

Proceedings - 17 th International Symposium GIESCO, Asti, Italy, 2011In order to validate a model of vine transpiration based on radiative surface temperature a field trial was conducted in a vineyard in the Dão region, centre of Portugal, with the cultivar “Touriga Nacional”. The model is based on the partition of net radiation between the components of the canopy (vines, soil, and grass cover), considering that the vines and the undercover (soil plus grass cover) act separately and in parallel. Thus, the latent heat flux from the vines to the atmosphere (lTc) is determined from vine net radiation (Rnc) and sensible heat flux (Hc). The partition of net radiation (Rn) between the undercover (Rns) and the vines (Rnc) is made considering the exponential form for radiation extinction, with the coefficient of extinction being corrected with a factor dependent on the zenital solar angle (j) while leaf area index (LAI) is corrected with a clumping factor, Ω(φ). Sensible heat flux from the vines (Hc) is calculated from radiative temperature (Tc) considering that the fluxes from the different origins are independent and that there are two resistances in series between the canopy and the atmosphere: the leaf boundary layer resistance (raHc) and the aerodynamic resistance of the crop (raH). Besides the estimation of the daily values of transpiration, the model allows to study the evolution of the different components of the radiation balance throughout the day. The daily evolution of the evaporation fraction from the vines (FEc) can be approximated by a concave curve. Values of FEc > 1 show that, under certain circumstances and periods of the day, energy used for transpiration (lTc) is greater than crop net radiation, which indicates that there are exchanges of energy between the several components of the surface, namely when evaporative demand from the atmosphere is high and there are no soil water restrictions. The model also shows that, regardless of the soil water status, transpiration is a big part of Rn when these values are low (in the beginning of the morning and late afternoon)

Primary Biliary Cholangitis: a Rare Diagnosis During Pregnancy

Primary biliary cholangitis is an autoimmune disease that mostly affects women. It is uncommon in women of childbearing age and the diagnosis during pregnancy is rare and can be challenging. Described here is a case of primary biliary cholangitis first manifesting during pregnancy, with the onset of pruritus, jaundice, biochemical liver abnormalities and positive antimitochondrial antibodies. Although treatment with ursodeoxycholic acid was started at the time of diagnosis, there was a progressive worsening of cholestatic biochemical markers throughout pregnancy. In addition, fasting hyperglycemia with polyhydramnios was diagnosed, consistent with gestational diabetes. She had a spontaneous preterm delivery at 31 weeks of gestation, of a newborn who was admitted to the neonatal intensive care unit but who subsequently had no long-term sequelae of preterm delivery. A maternal postpartum flare occurred. Treatment with ursodeoxycholic acid was well tolerated during pregnancy and lactation.info:eu-repo/semantics/publishedVersio