Cost of energy and environmental policy in Portuguese CO2 abatement—scenario analysis to 2020

This paper quantifies the contribution of Portuguese energy policies for total and marginal abatement costs (MAC) for CO₂ emissions for 2020. The TIMES_PT optimisation model was used to derive MAC curves from a set of policy scenarios including one or more of the following policies: ban on nuclear power; ban on new coal power plants without carbon sequestration and storage; incentives to natural gas power plants; and a cap on biomass use. The different MAC shows the policies’ effects in the potential for CO₂ abatement. In 2020, in the most encompassing policy scenario, with all current and planned policies, is possible to abate only up to +35% of 1990 emissions at a cost below 23 € t/CO₂. In the more flexible policy scenarios, it is possible to abate up to −10% of 1990 emissions below the same cost. The total energy system costs are 10–13% higher if all policies are implemented—76 to 101 B€—roughly the equivalent to 2.01–2.65% of the 2005 GDP. Thus, from a CO₂ emission mitigation perspective, the existing policies introduce significant inefficiencies, possibly related to other policy goals. The ban on nuclear power is the instrument that has the most significant effect in MAC.     

Risk factors in oil and gas industry returns: International evidence

The recent boom in oil prices has attracted many investors to oil companies in search of both returns and diversification benefits. This analysis of the risk factors of investing in the oil and gas industry in 34 countries finds evidence that oil price is a globally priced factor for the oil industry. The oil and gas sector in developed countries responds more strongly to oil price changes than in emerging markets. Oil and gas industry returns also respond asymmetrically to changes in oil prices; oil price rises have a greater impact than oil price drops. There is no parallel to the asymmetry of oil price changes in other industries related to commodities. If there is any asymmetry, it is in the opposite direction from oil. Negative commodity price changes have a greater impact than positive ones. The results seem to indicate that the oil and gas industry is distinguished by a pass-through effect.     

Regional energy system optimization – Potential for a regional heat market

Energy supply companies and industrial plants are likely to face new situations due to, for example, the introduction of new energy legislation, increased fuel prices and increased environmental awareness. These new prerequisites provide companies with new challenges but also new possibilities from which to benefit. Increased energy efficiency within companies and increased cooperation between different operators are two alternatives to meet the new conditions. A region characterized by a high density of energy-intensive processes is used in this study to find the economic potential of connecting three industrial plants and four energy companies, within three local district heating systems, to a regional heat market, in which different operators provide heat to a joint district heating grid. Also, different investment alternatives are studied. The results show that the economical potential for a heat market amounts to between 5 and 26 million EUR/year with payback times ranging from two to eleven years. However, the investment costs and the net benefit for the total system need to be allotted to the different operators, as they benefit economically to different extents from the introduction of a heat market. It is also shown that the emissions of CO₂ from the joint system would decrease compared to separate operation of the systems. However, the valuation of CO₂ emissions from electricity production is important as the difference of emitted CO₂ between the accounting methods exceeds 650 kton/year for some scenarios.     

Growth rate and medium composition strongly affect folate content in Saccharomyces cerevisiae

Folate content in a Saccharomyces cerevisiae strain was monitored during aerobic batch fermentation in synthetic growth medium, yeast peptone dextrose medium, and a molasses based medium. During growth in the synthetic medium large differences in intracellular folate content was observed at different phases. Specific folate levels, expressed per unit biomass, were highest during respiro-fermentative growth (120 microg/g) and decreased during the respiratory and stationary phases. Thus, the physiological state of the cells clearly affects the folate content. This was confirmed in chemostat cultures where total intracellular folate content increased linearly with increasing growth rate (r(2)=0.998), indicating high growth rate i.e. respiro-fermentative growth to be most favourable to obtain high specific folate content. In complex media however, much lower folate content (15-40 microg/g) was found throughout the batch growth. Only minor growth-phase related differences were detected. This shows the impact of cultivation medium on folate content in yeast. To further investigate which components that influence folate content, batch experiments in synthetic medium with addition of specific components were performed. Adding a raw mixture of peptides and amino acids (peptone) decreased folate levels extensively (90%) whereas adding amino acids one-by-one only had minor effects on the intracellular folate content. Furthermore, supplementing synthetic medium with pABA, folate or nucleotides did not change the intracellular folate content. This work constitutes the first steps towards an optimised process for production of natural folates for fortification purposes, as well as an effort to gain fundamental understanding of folate requirements in yeast in relation to environmental conditions.     

Association of single nucleotide polymorphisms in candidate genes previously related to genetic variation in fertility with phenotypic measurements of reproductive function in Holstein cows

Many genetic markers related to health or production traits are not evaluated in populations independent of the discovery population or related to phenotype. Here we evaluated 68 single nucleotide polymorphisms (SNP) in candidate genes previously associated with genetic merit for fertility and production traits for association with phenotypic measurements of fertility in a population of Holstein cows that was selected based on predicted transmitting ability (PTA) for daughter pregnancy rate (DPR; high, ≥1, n = 989; low, ≤ ?1.0, n = 1,285). Cows with a high PTA for DPR had higher pregnancy rate at first service, fewer services per conception, and fewer days open than cows with a low PTA for DPR. Of the 68 SNP, 11 were associated with pregnancy rate at first service, 16 with services per conception, and 19 with days open. Single nucleotide polymorphisms in 12 genes (BDH2, BSP3, CAST, CD2, CD14, FUT1, FYB, GCNT3, HSD17B7, IBSP, OCLN, and PCCB) had significant associations with 2 fertility traits, and SNP in 4 genes (CSPP1, FCER1G, PMM2, and TBC1D24) had significant associations with each of the 3 traits. Results from this experiment were compared with results from 2 earlier studies in which the SNP were associated with genetic estimates of fertility. One study involved the same animals as used here, and the other study was of an independent population of bulls. A total of 13 SNP associated with 1 or more phenotypic estimates of fertility were directionally associated with genetic estimates of fertility in the same cow population. Moreover, 14 SNP associated with reproductive phenotype were directionally associated with genetic estimates of fertility in the bull population. Nine SNP (located in BCAS, BSP3, CAST, FUT1, HSD17B7, OCLN, PCCB, PMM2, and TBC1D24) had a directional association with fertility in all 3 studies. Examination of the function of the genes with SNP associated with reproduction in more than one study indicates the importance of steroid hormones and immune function as determinants of reproductive function. All but 1 of the 68 evaluated SNP were variable in 11 breeds besides Holstein, indicating the potential effects of these SNP on reproductive function across breeds of cattle.     

Exopolysaccharides produced by Bifidobacterium longum IPLA E44 and Bifidobacterium animalis subsp. lactis IPLA R1 modify the composition and metabolic activity of human faecal microbiota in pH-controlled batch cultures

Exopolysaccharides (EPS) isolated from two Bifidobacterium strains, one of human intestinal origin (Bifidobacterium longum subsp. longum IPLA E44) and the other from dairy origin (Bifidobacterium animalis subsp. lactis IPLA R1), were subjected to in vitro chemically simulated gastrointestinal digestion, which showed the absence of degradation of both polymers in these conditions. Polymers were then used as carbon sources in pH-controlled faecal batch cultures and compared with the non-prebiotic carbohydrate glucose and the prebiotic inulin to determine changes in the composition of faecal bacteria. A set of eight fluorescent in situ hybridisation oligonucleotide probes targeting 16S rRNA sequences was used to quantify specific groups of microorganisms. Growth of the opportunistic pathogen Clostridium histolyticum occurred with all carbohydrates tested similarly to that found in negative control cultures without added carbohydrate and was mainly attributed to the culture conditions used rather than enhancement of growth by these substrates. Polymers E44 and R1 stimulated growth of Lactobacillus/Enterococcus, Bifidobacterium, and Bacteroides/Prevotella in a similar way to that seen with inulin. The EPS R1 also promoted growth of the Atopobium cluster during the first 24 h of fermentation. An increase in acetic and lactic acids was found during early stages of fermentation (first 10–24 h) correlating with increases of Lactobacillus, Bifidobacterium, and Atopobium. Propionic acid concentrations increased in old cultures, which was coincident with the enrichment of Clostridium cluster IX in cultures with EPS R1 and with the increases in Bacteroides in cultures with both microbial EPS (R1 and E44) and inulin. The lowest acetic to propionic acid ratio was obtained for EPS E44. None of the carbohydrates tested supported the growth of microorganisms from Clostridium clusters XIVa+b and IV, results that correlate with the poor butyrate production in the presence of EPS. Thus, EPS synthesized by bifidobacteria from dairy and intestinal origins can modulate the intestinal microbiota in vitro, promoting changes in some numerically and metabolically relevant microbial populations and shifts in the production of short chain fatty acids.     

The prebiotic effect of α-1,2 branched,low molecular weight dextran in the batch and continuous faecal fermentation system

The aim of this study was to establish the effect of smaller molecular weight (0.5 and 1.0 kDa) on prebiotic efficacy and its putative sustainability in the human gut. The prebiotic effect of α-1,2 branched, 0.5 and 1 kDa dextrans were evaluated in faecal batch fermentations as compared with inulin. Both dextrans induce similar selectivity towards Bifidobacterium sp., Lactobacillus/Enterococcus and Bacteroides/Prevotella, and producing similar concentrations of short chain fatty acids. However, the 0.5 kDa dextran was fermented faster than the 1 kDa dextran, where both produced lower amount of gas than inulin. The fermentation of 1 kDa dextran was further investigated in continuous gut models. The dextran increased Bifidobacterium and Roseburia sp. populations in the final vessel, while decreasing Clostridium histolyticum and Faecalibacterium prausnitzii. Overall, the α-1,2 branched, 1 kDa dextran induced selective effect on the gut microbiota and stimulated short chain fatty acids, indicating prebiotic sustainability in distal regions of the gut.     

Test systems and a method for express detection of synthetic food dyes in drinks

In this study, new test systems and express method were developed for the rapid detection of synthetic food dyes in drinks including alcoholic drinks, fruit juices, soft drinks and other non-alcoholic drinks. The detection is based on selective adsorption of synthetic food dyes from a drink by the specific adsorbent contained in the developed test system. The method allows screening of samples for synthetic food dyes in the presence of natural colors by differential spectrophotometry following adsorption. The said adsorbent provides adsorption of synthetic food dyes and substantially does not interact with natural dyes of drinks. Therefore, when a drink contains synthetic dyes, the color of the sample changes, whereas the color of a drink having only natural dyes stays substantially the same. This test can be used as a first step analysis for screening. So, only in a case when the test showed the presence of synthetic dyes in a drink, further laborious identification and quantitative determination of the revealed dyes could be performed. The use of such an approach reduces the time and costs required to perform the analysis.