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Cordero-Bueso G.,Pablo De Olavide University | Arroyo T.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | Valero E.,Pablo De Olavide University
International Journal of Food Microbiology | Year: 2014

This research deals with how two fungicide treatments against powdery mildew, penconazole as a systematic fungicide and sulfur as an inorganic broad-spectrum fungicide, affect the diversity and density of wine yeasts associated with grape berry surfaces and subsequent spontaneous fermentations. Unlike other studies in this area, this work aims to evaluate this effect on the population dynamics in the environment, the conditions of which are not reproducible in the laboratory. A long term (three year) sampling plan was thus devised. A minimum inhibitory concentration assay was also carried out in the laboratory in order to prove the influence of these antifungals on yeast populations. While both antifungal treatments (penconazole and sulfur) were similarly effective against powdery mildew, each had a very different effect on yeast populations. Penconazole showed the most negative effect on biodiversity in the vineyard and was the fungicide to which the isolated yeasts showed the greatest sensitivity. This study therefore evidences the suitability of treatment with sulfur, in both conventional and organic viticulture, to preserve the yeast population associated with grape berries, in particular the Saccharomyces cerevisiae species. © 2014 Elsevier B.V.

Fajardo C.,Complutense University of Madrid | Ortiz L.T.,Complutense University of Madrid | Rodriguez-Membibre M.L.,Complutense University of Madrid | Nande M.,Complutense University of Madrid | And 2 more authors.
Chemosphere | Year: 2012

In this work, nanoscale zero-valent iron (NZVI) particles have been used as an immobilisation strategy to reduce Pb and Zn availability and mobility in polluted soils. The application of NZVI to two soil microcosms (MPb and MZn) at a dose of 34mgg -1 soil efficiently immobilised Pb (25%) and zinc (20%). Exposure to NZVI had little impact on the microbial cellular viability and biological activity in the soils. Three bacterial genes (narG, nirS and gyrA) were used as treatment-related biomarkers. These biomarkers ruled out a broad bactericidal effect on the bulk soil microbial community. A transcriptome analysis of the genes did not reveal any changes in their expression ratios after the NZVI treatment: 1.6 (narG), 0.8 (nirS) and 0.7 (gyrA) in the MPb microcosm and 0.6 (narG), 1.2 (nirS) and 0.5 (gyrA) in the MZn microcosm. However, significant changes in the structure and composition of the soil bacteria population were detected by fluorescence in situ hybridisation. Thus, our results showed that NZVI toxicity could be highly dose and species dependent, and the effective applicability of the proposed molecular approach in assessing the impact of this immobilisation strategy on soil microbial population. © 2011 Elsevier Ltd.

Hernanz J.L.,Technical University of Madrid | Sanchez-Giron V.,Technical University of Madrid | Navarrete L.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | Sanchez M.J.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario
Field Crops Research | Year: 2014

In the last thirty years, grain producers in central Spain have begun a slow transition from conventional tillage (CT) to reduced tillage (RT) systems for the production of cereal crops in semiarid conditions, and nowadays most of them have adopted minimum tillage (MT) and an increasing number even no-tillage (NT) practices. The main reason underlying this shift is the cut down of the production costs through a reduction in the total energy use for crop production. The objectives of this study were to assess the crop yields, energy output and energy use efficiency for monoculture cereal and cereal-fallow rotation each managed using CT, MT and NT on a Vertic Luvisol in Alcalá de Henares, Madrid, Spain. Cropping systems included monoculture winter barley (Hordeum vulgare L.) (WB) six years; spring barley (SB) one year; monoculture winter wheat (WW) (Triticum aestivum L.) sixteen years; winter wheat-fallow rotation (F-WW), 4 years; and winter barley-fallow rotation (F-WB), 2 years. Total energy use was significantly lower in NT than in MT, and in this the latter was also significantly lower than in CT, regardless of cropping system considered. Average energy saved was 11% and 14% for MT and NT, respectively, in comparison with CT. Irrespective of cropping system, direct energy use averaged 2.68±0.28GJha-1year-1 in CT; 1.97±0.29GJha-1year-1 in MT; and 1.27±0.27GJha-1year-1 in NT, being all these figures significantly different. Indirect energy use averaged across cropping systems was highest in NT, 5.93±1.16GJha-1year-1; intermediate in CT, 5.7±1.26GJha-1year-1; and lowest in MT, 5.49±1.27GJha-1year-1. As all tillage systems received the same rates of seed and fertilizer, increased herbicide consumption in NT was responsible for its highest indirect energy use that was offset by its lowest direct energy use. In the cropping systems considered, no significant differences were observed between the crop yields, and crop yields per standing plant, obtained in each tillage system. Energy productivity mean values of each crop rotation were similar in NT and MT, and higher than those of CT. The pooled average energy productivity across crop rotations was 15% higher in MT than in CT, 19% higher in NT than in CT, and 3.7% higher in NT than in MT. Energy productivity of each tillage system increased linearly with the amount of rainfall from sowing to maturity. The slope of the regression lines reflects the efficiency of a tillage system in converting each millimetre of water received in energy productivity. For wheat, the largest slope corresponded to NT, intermediate to MT, and lowest to CT. For barley the largest slope was that of MT, intermediate that of NT, and the lowest that of CT. © 2014.

Cordero-Bueso G.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | Arroyo T.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | Serrano A.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | Tello J.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | And 3 more authors.
International Journal of Food Microbiology | Year: 2011

Wine production in most countries is based on the use of commercial strains leading to the colonisation of the wineries by these strains with the consequent reduction of autochthonous biodiversity. This implies that wine styles could therefore become standardised. The vineyard could be an important source of native yeasts of oenological interest. For this reason the objective of this study was to compare two agronomic conditions with the aim of preserving yeast biodiversity in the vineyard. A three year sampling plan was designed to evaluate the influence of different agronomic parameters on the biodiversity of fermentative grape yeasts. Thus two vineyards, one organic and one conventional, with three different grape varieties (Shiraz, Grenache and Barbera) were chosen. In total, 27 samples were collected from both vineyards. Of these, 1080 colonies were isolated and a total of 9 species were identified. The strains identified as Saccharomyces cerevisiae were genotyped by microsatellite analysis obtaining nine different electrophoretic patterns. Classical ecology indexes were used to obtain the richness (S), the biodiversity (H') and the dominance (D) of the species studied. The results indicated a clear influence on grape associated yeast diversity of the phytosanitary treatment used in the vineyard. This is the first time that classical ecology indexes have been used to study the ecology of the spontaneous fermentation of grape musts and the species Candida sorbosa and Pichia toletana have been described in vineyards of the Madrid winegrowing region. © 2010 Elsevier B.V.

Cordero-Bueso G.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | Esteve-Zarzoso B.,Rovira i Virgili University | Cabellos J.M.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | Gil-Diaz M.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario | Arroyo T.,Instituto Madrileno Of Investigacion Y Desarrollo Rural Agrario Y Alimentario
European Food Research and Technology | Year: 2013

Non-Saccharomyces yeast species assume an important role in wine flavor. Notwithstanding, the chemical basis for the flavor characteristics of wines from some grape varieties is not yet defined. The value of this work lies in the use of Malvar white grape, an autochthonous variety from Madrid (Spain) winegrowing region to conduct spontaneous fermentations. This is the first time that a comparative characterization of a wide range of non-Saccharomyces species and a comprehensive analysis of these yeast-derived volatiles has been carried out in this grape variety. β-glucosidase and pectinase (polygalacturonase) extracellular activities were tested on agar plates as primary selection criteria among the 504 non-Saccharomyces isolated from Malvar spontaneous fermentations during four consecutive harvests. Analysis of the wines obtained after fermentation using the selected yeast strains indicates that non-Saccharomyces yeasts isolated along the fermentative process seem that could have a positive impact, showing a high variability in the volatile compounds contributing to the organoleptic characteristics of Malvar wines. Torulaspora delbrueckii CLI 918 was defined as the yeast strain with potential interest for its contribution to the aromatic wine profile with flowery and fruity aromas and could be used in mixed starter cultures with Saccharomyces cerevisiae. However, Hanseniaspora guilliermondii increased the volatile acidity and ethyl acetate, but this species along with the genus Pichia and Candida seem to provide a high quantity of extracellular enzymes which may be beneficial in wine making. © 2012 Springer-Verlag Berlin Heidelberg.

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