Foraging decisions by rodents are key for the long-term maintenance of oak populations in which avian seed dispersers are absent or inefficient. Decisions are determined by the environmental setting ...in which acorn-rodent encounters occur. In particular, seed value, competition and predation risks have been found to modify rodent foraging decisions in forest and human-modified habitats. Nonetheless, there is little information about their joint effects on rodent behavior, and hence, local acorn dispersal (or predation). In this work, we manipulate and model the mouse-oak interaction in a Spanish dehesa, an anthropogenic savanna system in which nearby areas can show contrasting levels of ungulate densities and antipredatory cover. First, we conducted a large-scale cafeteria field experiment, where we modified ungulate presence and predation risk, and followed mouse foraging decisions under contrasting levels of moonlight and acorn availability. Then, we estimated the net effects of competition and risk by means of a transition probability model that simulated mouse foraging decisions. Our results show that mice are able to adapt their foraging decisions to the environmental context, affecting initial fates of handled acorns. Under high predation risks mice foraged opportunistically carrying away large and small seeds, whereas under safe conditions large acorns tended to be predated in situ. In addition, in the presence of ungulates lack of antipredatory cover around trees reduced mice activity outside tree canopies, and hence, large acorns had a higher probability of survival. Overall, our results point out that inter-specific interactions preventing efficient foraging by scatter-hoarders can reduce acorn predation. This suggests that the maintenance of the full set of seed consumers as well as top predators in dehesas may be key for promoting local dispersal.
Obtaining peptides with antioxidant properties by enzymatic hydrolysis has been widely described; however, the use of non-enzymatic methods to obtain peptides with antioxidant capacities has been ...poorly investigated. In this study, non-soluble proteins obtained from delipidated egg yolk granules were hydrolyzed with trypsin, and with a non-enzymatic method using sub-critical water hydrolysis under a non-oxidizing (nitrogen) and oxidizing (oxygen) atmosphere. The effect of the sub-critical water hydrolysis on the amino acids' composition of the hydrolysates was assessed. Furthermore, the antioxidant capacities of the hydrolysates were evaluated using the ABTS
scavenging assay, the DPPH radical scavenging activity assay, and by measuring the reducing power of the peptides, the peptides' ferrous ion chelating capacities, and the antioxidant effect of the peptides on beef homogenates. The hydrolysate obtained by sub-critical water hydrolysis under a nitrogen stream showed similar or better results in the antioxidant tests than those obtained using trypsin hydrolysis, except in the ferrous chelating capacity, where the trypsin hydrolysate showed the best performance. The oxidizing environment promoted by the oxygen in the other sub-critical water hydrolysis method tested produced the peptides with the lowest antioxidant capacities, due to changes in the primary structure of the peptides. These results suggest that the sub-critical water hydrolysis method under a nitrogen stream, in comparison with the enzymatic hydrolysis, is a reliable method to obtain peptides with good antioxidant capacities.
Food production in intensive farming systems can be unsustainable in several ways. Although hen egg is consumed worldwide as a very valuable and cheap source of protein, there is an evident lack of ...studies concerning the environmental performance of egg production. The European Union produces approximately 7 million tonnes of useable eggs per annum and Spain is one of the largest egg producers.
In this work, Life Cycle Assessment (LCA) methodology was applied to analyse the environmental impacts of intensive egg production using as a model a Spanish farm with 55,000 laying hens, producing about 13 million eggs per year. High quality inventory data was obtained directly from this facility. The main factors involved in egg production were included (hen feed, water, electricity, transport, cleaning elements, packaging material, replacement of exhausted laying hens, wastes and gas emissions). Inventory data were analysed using the ReCiPe Midpoint (H) V1.12/Europe Recipe H, the ReCiPe Endpoint (H) V1.12/Europe Recipe H methods and the Greenhouse Gas Protocol V1.01/C02 eq (kg) by means of the LCA software package SimaPro v8.
LCA results showed that, according to normalization results, natural land transformation was the most prominent category, followed by terrestrial ecotoxicity and freshwater ecotoxicity. The most important source of harmful environmental impacts in all the categories under assessment was the production of the hen feed and, to a lesser extent, the purchase of new laying hens to replace the old ones. On the contrary, water consumption and the employment of chemicals for cleaning barely influenced the impact. One aspect that was noteworthy was the beneficial effect on environmental impact produced by the sale of old laying hens for meat production, especially on the urban land occupation and metal depletion categories. Additionally, the carbon footprint of egg production was calculated and a value of 2.66 kgCO2eq per dozen eggs was obtained. Environmental improvement actions should be directed mainly towards optimizing the hen feed formulation, not only from an economic perspective, but also considering the environmental aspects involved.
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•Intensive egg production in Europe was analysed by LCA.•Natural land transformation was the most notably affected category.•Feeding and young chicks breeding were the most relevant sources of impacts.•Water consumption and cleaning products use barely contribute to the total impact.•Carbon footprint can be reduced by reformulating the hen fodder.
Microplastics (MPs), and specifically microfibres (MPFs), are ubiquitous in water bodies, including wastewater and drinking water. In this work, a thorough literature review on the occurrence and ...removal of MPs, and specifically MPFs in WWTPs and DWTPs, has been carried out. When the water is treated, an average microfiber removal efficiency over 70% is achieved in WWTPs and DWTPs. These high percentages are still inefficient for avoiding the presence of a large number of microfibres in treated wastewater and also in tap water. RSF, DAF, oxidation ditch and CAS processes have been described as the most efficient treatments for eliminating MPFs from wastewater treatment. It is remarkable the wide range of the data reported on this topic; for example, treated wastewater contains between not detected and 347 MPFs/L, whereas tap water contains between not detected and 168 MPFs/L. Microfibres constitute more than half of the MPs found in treated wastewater and sewage sludge, whereas in DWTP effluents the percentage of MPFs is around 32%. Nevertheless, the relative amount of MPFs reported in tap water is notably higher (71%). Microfibres from WWTPs are discharged to the environment, being a source of MP pollution. Additionally, MPs released by DWTPs directly enter the drinking water lines, which constitute a direct route for MP human consumption, so that it has been estimated that an adult may ingest an average value of 7500 MPFs per year only via tap water. Thus, this review provides an update on the performance of WWTPs and DWTPs in removing MPs from water, which is an issue of great interest.
The swine slurry is a mixture of manure, urine, and cleaning water from pig livestock farms, characterized by its high chemical oxygen demand (COD) and ammonia concentration. This effluent needs to ...be treated before being spilled to avoid negative environmental impacts as eutrophication of surface water reservoirs. In this study, an untreated slurry and two pig slurries pre-treated by anaerobic digestion with and without ammonia trapping were treated biologically by Phanerochaete chrysosporium. The effect on the biological treatment of pre-treating the raw slurry by sieving and centrifugation was evaluated. Samples were inoculated with 3 g/L (dry matter) of fungus and incubated at 26 °C during 10 days in a batch reactor. The activity of ligninolytic enzymes (LiP, MnP and Lac), colour, COD, total nitrogen and BOD5 evolution during the treatment were analysed. For undigested slurries, the best results were obtained for sieved slurry, reaching removal efficiencies for soluble COD and colour around 68% and 78%, respectively. For digested effluents, the digestate coming from the reactor with ammonia trapping membrane showed the best results with efficiencies of 38% for soluble COD and 35% for colour. These results provide new insights into the application of this fungus as complementary method to treat swine wastewaters.
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•P. chrysosporium was evaluated on both raw and digested swine slurries treatment.•The influence of sieving and centrifugation steps on the efficiency of treatment was tested.•Centrifugation pretreatment allowed decreases higher than 60% in COD, TN and colour.•Sieving was key for optimal enzyme synthesis, reaching highest values after 2 days.•Results obtained expand the biotechnological applications of P. chrysosporium.
•Waste activated sludge is a renewable and sustainable source of biomolecules.•Proteins, lipids, fatty acids, enzymes and humic acids can be recovered from sludge.•High protein recovery by ...precipitation using ultrasound and alkali treatments.•Polymeric membranes of 30–50 kDa were the most suitable to recover humic acids.•Two integrated methods for the complete recycling of activated sludge were proposed.
The need of developing a new growth model based on circular economy has led to an increasing interest in the revalorization of urban and industrial wastewaters in order to use the resources efficiently. The most stablished way of valorising these residues implies the energy production in the form of biomethane. However, urban and industrial wastewaters can also be considered promising raw sources for the recovery of valuable chemical compounds. Especially, waste activated sludge from water treatment plants is a fantastic source of biomolecules such as lipids (triglycerides or fatty acids), proteins and enzymes, carbohydrates, and humic and fulvic acids. However, prior to the recovery of these biocompounds, sludge solubilization processes (thermal hydrolysis, sonication and acidification, among others) must be conducted, in order to break the cell walls and release the protoplasmic content into the liquid media, thus obtaining a matrix of high complexity, which condition the possible strategies to be applied.
This review gathered and discussed in-depth the studies that deal with the recovery of valuable biocompounds from secondary waste activated sludge. Furthermore, other types of sludge comparable to the activated one, such as cell cultures and food-related sources, have been also discussed here, in order to be used as a starting point for further research on the valorisation of waste activated sludge.
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This study deals with the Indigo Carmine (IC) dye removal using synthetic mesoporous Titanium dioxide (TiO2) nanoparticles. The surface charge investigation shows a pHzc equal to 4.25. The central ...composite design (CCD) model optimization of the adsorption process identified 57 min as the optimal contact time. For optimum IC contents of 30 and 58 mg/L, the recorded adsorption capacities were 123 and 261 mg/g in the dark reactor (DR) and sunlight reactor (SR), respectively. The thermodynamic investigation suggests an endothermic and spontaneous physisorption process, and the regeneration tests show higher stability of the mesoporous TiO2 in the SR. SEM and TEM analyses show a TiO2 agglomeration in DR and nanoparticles swelling in SR.
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•Optimum contact time of 57 min for adsorption and photosorption based on CCD model.•Yields at optimum conditions were 82% for adsorption and 90% for photosorption.•IC adsorption onto TiO2 nanoparticles was an endothermic and spontaneous process.•Low enthalpy values obtained proved that IC adsorption is a physisorption process.•TiO2 nanoparticles exhibited higher stability after 10 regeneration cycles.
Beef meat, one of the more environmentally costly animal-based foods, can be produced in two general ways, as the main product on specialised farms or as a co-product on dairy farms. In this study, ...two cases (a semi-confinement dairy farm (A) and a pasture-based dairy farm (B)) have been analysed by means of LCA to evaluate the environmental impacts associated with the coproduction of beef meat. In both cases, purchased feed production was found to be the main cause of environmental impacts in most of the categories considered. Additionally, cow emissions to air were the main contributor for the global warming category. Comparing the two dairy systems, notably lower environmental impacts were obtained for B in 13 of the 18 categories analysed. Regarding CF, 8.10 and 8.88 kg CO
2
eq/kg LW were obtained for A and B, respectively. These CF values were within the wide range found in the literature for beef meat (1.2-42.6 kg CO
2
eq/kg LW). Beef calves and cull cows are an important output of dairy farming, so that coproduction enables milk and meat with lower CF and associated environmental impacts to be obtained. In addition, the variability of the data found in literature and the lack of LCA studies based on real data for beef meat coproduced on dairy farms evidence the importance of in-depth study of this interesting topic.
Lipid rafts are cholesterol- and sphingomyelin-enriched microdomains that provide a highly saturated and viscous physicochemical microenvironment to promote protein-lipid and protein-protein ...interactions. We purified lipid rafts from human frontal cortex from normal, early motor stages of Parkinson's disease (PD) and incidental Parkinson's disease (iPD) subjects and analyzed their lipid composition. We observed that lipid rafts from PD and iPD cortices exhibit dramatic reductions in their contents of n-3 and n-6 long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (22:6-n3) and arachidonic acid (20:4n-6). Also, saturated fatty acids (16:0 and 18:0) were significantly higher than in control brains. Paralleling these findings, unsaturation and peroxidability indices were considerably reduced in PD and iPD lipid rafts. Lipid classes were also affected in PD and iPD lipid rafts. Thus, phosphatidylserine and phosphatidylinositol were increased in PD and iPD, whereas cerebrosides and sulfatides and plasmalogen levels were considerably diminished. Our data pinpoint a dramatic increase in lipid raft order due to the aberrant biochemical structure in PD and iPD and indicate that these abnormalities of lipid rafts in the frontal cortex occur at early stages of PD pathology. The findings correlate with abnormal lipid raft signaling and cognitive decline observed during the development of these neurodegenerative disorders.
Thymol is an active agent with remarkable antimicrobial properties but with low solubility in water and is able to exert a negative effect on the mechanical properties of protein-based films. ...Furthermore, it is highly volatile and during the drying of the film-forming solution it may be lost through evaporation, a question that has barely been studied.
In a previous investigation, the encapsulation of thymol using PLA was optimized, and, in the present study, these PLA nanoparticles are incorporated into gelatine films to assess their effect on the film properties and thymol evaporation during the drying of the film-forming solution.
At the thymol concentrations tested, all the free thymol was completely evaporated during the drying of the film-forming solution, while a part of the thymol encapsulated in PLA nanoparticles remained in the gelatine film matrix. The gelatine films with PLA-thymol nanoparticles showed high transparency, a homogeneous microstructure and antimicrobial properties.
•Free thymol was completely evaporated during the drying of the film-forming solution.•Part of the thymol encapsulated remained in the gelatine film matrix.•Gelatine films with PLA-thymol nanoparticles showed a homogeneous microstructure.•Thymol release behaviour can be explained by the Arrhenius activation model.•Gelatine films with nanoparticles showed antimicrobial properties on apple pieces.
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