Monday, 25 April 2016

Temporal and spatial changes in soil micronutrients in managed Nothofagus pumilio forest of Tierra del Fuego, Argentina

Environmental Earth Sciences (2016) 75:738
DOI: 10.1007/s12665-016-5470-3


Soil organic components are important factors in the quality and productivity of forest ecosystems. Timber harvesting reduces plant cover and the amount of organic matter in forest floor layer, increases surface runoff, soil erosion and alters microclimatic conditions over large areas. These changes can have important implications for nutrient cycling dynamics and soil organic matter mineralization. Fueguian temperate forests of Nothofagus pumilio (lenga) have been intensely harvested for the last decades, mainly by shelterwood-cut silvicultural system. Harvesting removes nutrients contained in logs from the site, modifies light, temperature and soil humidity, constraining nutrient cycling process. In this study, we evaluate available copper (Cua), zinc (Zna), iron (Fea), and manganese (Mna) concentrations and reservoirs in stands that represent a chronosequence and their respective primary forests (controls): stands cut 1 year ago, stands cut 5–10 years ago, and stands harvested more than 50 years ago. Concentrations of Zna and Cua in primary forest were 39.9 and 2.6 mg/kg, and increased in harvested sites to 60.5 and 3.2 mg/kg, respectively. Fea and Mna concentrations showed similar ranges in both harvested and control sites. Recent harvested sites showed the highest Cua concentrations. Micronutrient reservoirs showed similar ranges in both harvested and primary forests. We concluded that micronutrient availability changes at short term after forest harvesting; thus, the inclusion of soil fertility assessment in forest management plans should be incorporated to preserve the fertility of lenga forests soils and ensure sustainability.

Saturday, 2 April 2016

Changes in Cd, Cu, Ni, Pb and Zn Fractionation and Liberation Due to Mussel Shell Amendment on a Mine Soil

Land Degradation and Development 27 (2016) 1276–1285
DOI: 10.1002/ldr.2505


Mining activities are related to relevant environmental pollution issues that should be controlled. We used sequential extractions to fractionate Cd, Cu, Ni, Pb and Zn retained on unamended or mussel shell-amended mine soil samples, all of them treated with a mixture of the five heavy metals (total metal concentration of 1·57 mmol L−1), after 1, 7 and 30 days of incubation. In addition, we used the stirred flow chamber technique to study the release of each of the five heavy metals from these different unamended and shell-amended soil samples. The results indicate that the shell amendment caused a decrease in the most soluble fraction, while increasing the most recalcitrant (least mobile) fraction. With equivalent implications, the stirred flow chamber experiments showed that mussel shell amendment was associated to a decrease in heavy metal release and increased retention. The highest mussel shell dose and incubation time caused the most relevant changes in pH values and thus in metal retention, also indicating the importance of pH modifications in the mechanism of retention acting in the amended samples. In view of these results, the use of mussel shell amendment can be encouraged to increase heavy metal retention in acid mine soils, in order to minimise risks of environmental pollution. 

Friday, 1 April 2016

Study of metal transport through pine bark for reutilization as a biosorbent

Chemosphere 149 (2016) 146–153


The potential utilization of pine bark as a biosorbent for the treatment of metal-contaminated soils and waters has been evaluated in transport experiments using laboratory columns. Solutions containing the metals Cu, Pb, Zn, Ni or Cd, each one individually and at three different concentrations (2.5, 10 and 25 mM) were tested. Pine bark affected metal transport and the breakthrough curves, producing a reduction of their concentrations in the solution and a clear retardation with respect to an inert tracer. At metal concentrations equal to 2.5 mM, 100% of the assayed elements were removed from the solution in the pine bark column. At the 10 mM metal concentration, the percentage of metals retained fell to 38–67% of the amount added, whereas at the 25 mM metal concentration, only 16–43% was retained. In all cases, the highest retention capacity corresponded to Pb, and the lowest to Zn, whereas Cu, Cd and Ni produced intermediate comparable results. The analysis of the pine bark within the columns after the transport experiment showed that the metals entering the column adsorb progressively until a saturation concentration is reached in the whole column, and only then they can be released at significant concentrations. This saturation concentration was approximately 70 mmol kg−1 for Cd, Ni and Zn, 100 mmol kg−1 for Cu, and 125 mmol kg−1 for Pb. Overall, our experiments have shown the high effectiveness of pine bark to retain the assayed metals in stable forms of low mobility.

Tuesday, 15 March 2016

Influence of pH on viscoelastic properties of heat-induced gels obtained with a β-Lactoglobulin fraction isolated from bovine milk whey hydrolysates

Food Chemistry, 219, 2017, 169–178


A β-Lactoglobulin fraction (r-βLg) was isolated from whey hydrolysates produced with cardosins from Cynara cardunculus. The impact of the hydrolysis process on the r-βLg structure and the rheological properties of heat-induced gels obtained thereafter were studied at different pH values. Differences were observed between r-βLg and commercial β-Lg used as control. Higher values for the fluorescence emission intensity and red shifts of the emission wavelength of r-βLg suggested changes in its tertiary structure and more solvent-exposed tryptophan residues. Circular dichroism spectra also supported these evidences indicating that hydrolysis yielded an intermediate (non-native) β-Lg state.

The thermal history of r-βLg through the new adopted conformation improved the microstructure of the gels at acidic pH. So, a new microstructure with better rheological characteristics (higher conformational flexibility and lower rigidity) and greater water holding ability was founded for r-βLg gel. These results were reflected in the microstructural analysis by scanning electron microscopy.

Monday, 14 March 2016

Contributions of a compost-biochar mixture to the metal sorption capacity of a mine tailing

Environmental Science and Pollution Research
February 2016, Volume 23, Issue 3, pp 2595–2602
DOI: 10.1007/s11356-015-5489-0


One technique applied to restore degraded or contaminated soils is to use amendments made of different types of waste materials, which in turn may contain metals such as Cu, Pb and Zn. For this reason, it is important to determine the capacity of the soil to retain these materials, and to compare the sorption capacity between an amended soil and another unamended soil. The aim of this study was to determine the mobility and availability of these metals in the soil after applying the amendment, and how it affected the soil’s sorption capacity. Sorption isotherms were compared with the empirical models of Langmuir and Freundlich to estimate the sorption capacity. The overall capacity of the soils to sorb Cu, Pb or Zn was evaluated as the slope Kr. The amendments used in this study were a mixture made of compost and biochar in different proportions (20, 40, 60, 100 %), which were applied to the mine tailing from a settling pond from a copper mine. The mine tailing that were amended with the mixture of compost and biochar had a higher sorption capacity than the mine tailing from the unamended pond, and their sorption isotherms had a greater affinity towards Cu, Pb and Zn than the mine tailing that was studied. Therefore, the results obtained show that adding a mixture of compost and biochar favours the retention of Cu, Pb and Zn in mine tailing.

Sunday, 13 March 2016

Assessing the influence of technosol and biochar amendments combined with Brassica juncea L. on the fractionation of Cu, Ni, Pb and Zn in a polluted mine soil

Journal of Soils and Sediments
February 2016, Volume 16, Issue 2, pp 339–348
DOI: 10.1007/s11368-015-1222-3



Soil metal pollution is a widespread problem around the world and remediation of these soils is difficult. The objective of this study was to investigate the effect of two different strategies on the chemical fractions of metals in a soil of a depleted copper mine: (1) amending with a mixture of a technosol made of wastes and biochar and (2) amending combined with planting vegetation (Brassica juncea).

A 3-month greenhouse experiment was carried out to evaluate the effects of organic amendments and vegetation on the metal fractionation of Cu, Ni, Pb and Zn in a mine soil of the depleted copper mine at Touro (Spain). We compared the influence of organic amendments alone (technosol + biochar) and combined with mustard plants (Brassica juncea L.).

The results showed that amending with a technosol made of wastes promoted plant growth (from 0.7 to 2.9 g of biomass produced) and reduced the CaCl2-extractable metal concentration in soil, reduced the mobility factor of Cu from 18.3 to 1.6, Ni from 47.5 to 2.3 and Pb from 17.9 to 2.1, and also reduced the concentration of metals in the mobile soil fractions. It was not possible to grow up Brassica juncea plants in the untreated settling pond soil due to the extremely degraded conditions of that soil. However, the application of the used technosol increased the Pb and Zn pseudototal concentrations in the amended soils.

We conclude that the combination of amending with wastes and planting B. juncea provides little additional benefit for remediating a metal-polluted soil compared with incorporation of wastes alone.

Thursday, 3 March 2016

Contribution of waste and biochar amendment to the sorption of metals in a copper mine tailing

CATENA
Volume 137, February 2016, Pages 120–125
http://dx.doi.org/10.1016/j.catena.2015.09.010


One technique applied to restore degraded or contaminated soils is to use amendments made of different types of waste materials, which in turn may contain metals such as Cu, Pb and Zn. For this reason it is important to determine the capacity of the soil to retain these materials, and to compare the sorption capacity between an amended soil and another unamended soil. The aim of this study was to determine the chemical behaviour of these metals in the soil after applying the amendment, and how it affected the soil's sorption capacity. Another aim was to study the contribution of contaminating elements from the amendment itself. The amendments used in this study were a mixture made of waste material (sewage sludges, sludges from an aluminium plant, ash, food industry wastes, and sands from a wastewater treatment plant) and biochar (biomass of Acacia dealbata) (97%:3%) in different soil/amendment proportions. The soil was from a mine tailing. The mine tailings were amended with the mixture of waste and biochar which had a higher sorption capacity than the soil from the pond. The samples with amendment had a greater affinity for Cu, Pb and Zn than the mine soil. The results obtained show that adding a mixture made of waste and biochar favours the retention of Cu, Pb and Zn in mine tailing from metal mines.

Wednesday, 2 March 2016

Histolocalization of aldehyde accumulation in citral-treated Arabidopsis thaliana roots

Allelopathy Journal 37:71-76 · 2016


Growth and development of Arabidopsis thaliana seedlings treated with the essential oil component citral have been severely affected. We analyzed whether citral can enter and accumulate into the roots and we found that it interferes with the plant metabolism accumulating mainly in the differentiation zone. Besides, the distribution of stained zones varied with the experimental time.

Tuesday, 1 March 2016

Nickel, Lead and Zinc Sorption in a Reclaimed Settling Pond Soil

Pedosphere
Volume 26, Issue 1, February 2016, Pages 39-48
doi:10.1016/S1002-0160(15)60020-0


The wastes used to amend soils sometimes have high concentrations of metals such as nickel (Ni), lead (Pb) and zinc (Zn). To determine the capacity of soils to retain these metals, the sorption capacities of different mine soils with and without reclamation treatments (tree vegetation and waste amendment) for Ni, Pb and Zn in individual and competitive situations were evaluated using the batch sorption technique. The untreated settling pond soil had low capacity for Ni, Pb and Zn retention. The site amended with wastes (sewage sludges and paper mill residues) increased the sorption capacity most, probably because of the higher concentrations of soil components with high retention capacity such as carbon and clay fraction. No significant competition was observed between metals in the competitive sorption experiment, indicating that the maximum of sorption was not achieved by adding 0.5 mmol L−1 of metal. We can conclude that, despite the possible additions of Ni, Pb and Zn from wastes to degraded soils, sewage sludges and paper mill residues have a high sorption capacity that would prevent the metals from being in a mobile form.

Monday, 22 February 2016

A widely used spectrophotometric assay to quantify olive oil biophenols according to the health claim (EU Reg. 432/2012)

European Journal of Lipid Science and Technology
DOI: 10.1002/ejlt.201500313


The purpose of this work was to find a simple, cheap, and suitable method, among the most widely employed, able to guarantee a proper determination and quantification of the phenolic content of extra virgin olive oils (EVOOs), in order to satisfy the requirements of the specific health claim (EU Reg. 432/2012). Total phenolic content by Folin–Ciocalteu (FC) was used and compared versus phenolic profile by HPLC-UV, considering this latter as the most sensitive and specific method for evaluating the phenolic content. Both protocols were performed before and after an acid hydrolysis of the polar phenolic fraction that involves a break of the bound forms of hydroxytyrosol (HTyr) and tyrosol (Tyr), with a simplification of the phenolic profile, and quantification of their total free forms. Results of the phenolic compounds of twelve EVOOs, determined by the different analytical approaches, were statistically compared by means of two-tailed paired t-tests: data obtained by the FC assay (expressed as HTyr) before and/or after acid hydrolysis were statistically comparable with results obtained by acid hydrolysis-HPLC (as sum of HTyr and Tyr).

Saturday, 20 February 2016

Dissipation of fungicides residues along winemaking, and their effects on fermentation and the volatile composition of wines

Journal of Agricultural and Food Chemistry


The effects of four fungicides commonly used for the control of fungal diseases in vines and grapes in the course of winemaking was tested. The concentration of fungicide residues was monitored throughout the process in order to establish their kinetics of dissipation. In all cases the percentages of dissipation were higher than 68% which shows the detoxificant effect of the winemaking process. On the other hand, the effect of the fungicide residues on the aroma composition of Tempranillo red wines was tested.

Wednesday, 17 February 2016

Cu retention in an acid soil amended with perlite winery waste

Environmental Science and Pollution Research (2016), 23, 3789–3798
DOI: 10.1007/s11356-015-5639-4


The effect of perlite waste from a winery on general soil characteristics and Cu adsorption was assessed. The studied soil was amended with different perlite waste concentrations corresponding to 10, 20, 40 and 80 Mg ha−1. General soil characteristics and Cu adsorption and desorption curves were determined after different incubation times (from 1 day to 8 months). The addition of perlite waste to the soil increased the amounts of organic matter as well as soil nutrients such as phosphorus and potassium, and these increments were stable with time. An increase in Cu adsorption capacity was also detected in the perlite waste-amended soils. The effect of perlite waste addition to the soil had special relevance on its Cu adsorption capacity at low coverage concentrations and on the energy of the soil-Cu bonds.

Tuesday, 16 February 2016

Xylitol production in immobilized cultures: a recent review

Critical Reviews in Biotechnology 36 (2016)


Xylitol is a pentahydroxy sugar alcohol coming from xylose with many applications in the food and pharmaceutical industries as a low caloric sweetener suitable for diabetics and as an active ingredient in several biomedical applications. The microbial bioproduction of xylitol from natural xylose coming from lignocellulosic materials appears a sustainable and a promising alternative to chemical synthesis, which works at stronger reaction conditions and generates undesirable co-products which must be removed. There are several reviews that study the metabolic pathways in wild and transformed xylitol producing yeasts and the culture conditions that enhance xylitol accumulation, which are mainly related to the need of microaerobiose for the best producing wild yeasts. Nevertheless, there are relatively few studies focusing on the engineering aspects related to scalable systems and bioreactors that could result in a final industrial stage. This review explores recent advances on xylitol production using immobilized systems, which have been proposed to facilitate the reuse of the biocatalyst for extended periods and the main types of bioreactors available assayed for this purpose.

Monday, 15 February 2016

Oxidation of edible animal fats. Comparison of the performance of different quantification methods and of a proposed new semi-objective colour scale-based method

Food Chemistry, 217 (2017) 743–749


The agreement among the results determined for the main parameters used in the evaluation of the fat auto-oxidation was investigated in animal fats (butter fat, subcutaneous pig back-fat and subcutaneous ham fat). Also, graduated colour scales representing the colour change during storage/ripening were developed for the three types of fat, and the values read in these scales were correlated with the values observed for the different parameters indicating fat oxidation.

In general good correlation among the values of the different parameters was observed (e.g. TBA value correlated with the peroxide value: r = 0.466 for butter and r = 0.898 for back-fat). A reasonable correlation was observed between the values read in the developed colour scales and the values for the other parameters determined (e.g. values of r = 0.320 and r = 0.793 with peroxide value for butter and back-fat, respectively, and of r = 0.767 and r = 0.498 with TBA value for back-fat and ham fat, respectively).

Tuesday, 2 February 2016

Phenolics production from alkaline hydrolysis of autohydrolysis liquors

CyTA - Journal of Food, 14 (2016) 255-265


The objective of this work was to study the release, identification and characterization of phenolic compounds by saponification of non-isothermal autohydrolysis liquors of corn (Zea mays) cobs and Eucalyptus globulus. Corn cobs and E. globulus are lignocellulosic materials with high contents in cellulose and hemicelluloses. Efficient use of these materials can be achieved using autohydrolysis as the first stage of a biorefinery, resulting in a solid phase rich in cellulose and lignin, and a liquid phase containing essentially hemicelluloses-derived compounds and phenolic compounds from the partial solubilization of lignin. This work studied the combination of alkaline hydrolysis and extraction with organic solvents to maximize the amounts of released phenolic compounds since these compounds are interesting for their properties and food applications.

Monday, 1 February 2016

Airborne pollen trends in the Iberian Peninsula

Science of the Total Environment
DOI: 10.1016/j.scitotenv.2016.01.069


Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants.

Saturday, 16 January 2016

Agronomic performance of maize populations divergently selected for diferulate cross-linkage

Journal of Agricultural Science
DOI: 10.1017/S0021859615001161


The direct response of a divergent selection programme for total cell wall ester-linked diferulate concentration in maize pith stalk tissues and its indirect effect on cell wall degradability and corn borer resistance have been previously evaluated. Since increased total diferulate concentration is expected to improve crop performance in response to corn borers, the objective of the present research was to evaluate the indirect response of the divergent selection for diferulates on agronomic traits under corn borer infestation. For this purpose, five maize populations with contrasting total diferulate concentrations were evaluated four environments for performance under protected and infested conditions. Measured traits were: days to anthesis, days to silking, plant height, stalk lodging, grain moisture at harvest and grain yield. High diferulate populations showed a significant reduction in anthesis (precocity), and were 11 cm taller than the starting population, while low diferulate populations were 9 cm shorter, and showed nearly 1 t/ha lower grain yield than the original and high diferulate populations. The analysis showed that cycles of selection were positively correlated with flowering, plant height and grain yield. The infestations with borers produced >1 t/ha of reduction in grain yield; although the higher diferulate populations showed a better performance under infestation than the low diferulate populations. This positive effect on the grain yield by increasing diferulate content can be considered an extra in order to breed for resistance to corn borers.

Friday, 15 January 2016

Oleaceae cross-reactions as potential pollinosis cause in urban areas

Science of the Total Environment
DOI: 10.1016/j.scitotenv.2015.10.107


It is worth noting the allergological problems induced by a not accurate design of the ornamental vegetation in the parks and streets of the cities. Usually, in the Oleaceae family, only the olive pollen is considered an important aeroallergen but other species of the family could be an important source of airborne pollen allergens. Pollen from Fraxinus, Olea and Ligustrum and its main aeroallergens were sampled in the atmosphere of an urban area in North-Western Spain during 2011. The allergen bioaerosol content was quantified by using specific 2-site ELISA and Ole e 1 antibodies. The Fra e 1 and Lig v 1 allergens were detected by means Ole e 1 antibodies. This fact demonstrates the cross-reactivity between the main allergens of Fraxinus, Olea and Ligustrum, plants widely species used as ornamental in the cities. Therefore, the urban allergenic people sensitized to Olea pollen could present allergenic reactions during the winter (due to ash pollen allergens), the spring (caused by olive pollen allergens) and the early summer (triggered by the privet flowering). As a consequence, sensitivity to the pollen of one species may favour development of sensitivity to all three species as consequence of the priming effect. The combination of pollen count and the allergen quantification must be assessed in the epidemiologic study of allergic respiratory diseases.

Wednesday, 13 January 2016

Acidification of mixtures of granite powder and compost for reuse in plant production

Compost Science & Utilization, 24 (2016)


We evaluated the utilization of granite powder—a residue of stone cutting and polishing resulting from its preparation for construction and ornamental use—in the preparation of nursery potting mixtures, within a general objective of waste recycling and reuse. Granite powder was blended with two composts of different origins and properties: one elaborated from the organic fraction of municipal solid waste (MSW), and another from pine bark. Since all materials presented pH values over 8, which are excessive for growing most vegetal species, the use of iron sulphate to acidify them has been assessed. Three doses of iron sulphate (14, 69, and 97 g kg−1, equivalent to 0.1, 0.5, and 0.7 meq H+ g−1) were added to the granitic powder and mixtures with 25 or 75% (v/v) of each compost, which were incubated in the laboratory during 30 days. Doses of iron sulphate above 0.1 meq H+ g−1 resulted in excessive electrical conductivity (>2 dS m−1) in all the samples, and too low pH values (<5) in most of them. The productivity of granite powder/compost mixtures acidified with 0.1 meq H+ g−1 was tested in a greenhouse experiment with ryegrass, where it was observed that plant productivity increased with respect to a control commercial substrate based on peat, in particular when the MSW compost was employed. On the basis of the physicochemical properties of the mixtures and the results of the greenhouse experiment, the use of granite powder mixed with 75% of MSW compost (v/v), acidified with 14 g kg−1 of iron sulphate (0.1 meq H+ g−1) is recommended.

Tuesday, 12 January 2016

Application of transit data analysis and artificial neural network in the prediction of discharge of Lor River, NW Spain

Water Science & Technology (2016)
DOI: 10.2166/wst.2016.002


Transit data analysis and artificial neural networks (ANNs) have proven to be a useful tool for characterizing and modelling non-linear hydrological processes. In this paper, these methods have been used to characterize and to predict the discharge of Lor River (North Western of Spain), one, two and three days ahead. Transit data analyses have showed a coefficient of correlation of 0.53 for a lag between precipitation and discharge of one day. By other hand, temperature and discharge has a coefficient of correlation negative (−0.43) for a delay of 19 day. The ANNs developed provide a good result for the validation period, with R2 between 0.92 and 0.80. Furthermore, these prediction models have been tested with discharge data from a period of 16 years later. Results of this testing period also show a good correlation with a R2 between 0.91 and 0.64. Overall, results indicate that ANNs are a good tool to predict river discharge with a small number of input variables.