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Due to the important contribution that it makes to human nutrition, maize is one of the most widely-consumed cereals in the world. There is, therefore, high demand for fertilizers that will maintain maize production at both high yield and quality levels. The objective of this work was to study the effect of foliar fertilization using a biostimulant, obtained by enzymatic hydrolysis from chicken feathers, on the productivity and quality of maize crops (Zea mays, L. cv PR32W86 Pioneer), located in Trujillanos (Extremadura, Spain), over two consecutive seasons.Foliar biostimulant/biofertilizer was applied three times each season and at two rates (3.6 and 7.2 l ha -1 ). At the higher rate and for both seasons, foliar fertilization significantly increased the leaf concentrations of macro-and micronutrients, while grain protein content and yield increased by 26% and 14%. These results suggest that the foliar use of this biostimulant could be of great interest to the farmer for improving both maize crop yield and quality.

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Currently, there is a growing interest in the use of non-Saccharomyces yeast to enhance the aromatic quality of wine, with pure or mixed cultures, as well as sequential inoculation. Volatile components of wines were closely related to their sensory quality. Hence, to study the evolution of volatile compounds during fermentation was of great interest. For this, sampling methods that did not alter the volume of fermentation media were the most suitable. This work reports the usefulness of headspace sorptive extraction as non-invasive method to monitor the changes in volatile compounds during fermentation. This method allowed monitoring of 141 compounds throughout the process of fermentation by Saccharomyces cerevisiae and Lachancea thermotolerans strains. Both strains showed a similar ability to ferment a must with high sugar content. The S. cerevisiae strain produced higher amount of volatile compounds especially esters that constitutes fruity aroma than L. thermotorelans.

The present study has been carried out in an organic winery established in 2003 in the Denomination of Origin ''Sierras de Málaga'' (Southern Spain) region during the 2007 vintage. The aim of this work was to ascertain the yeast microflora present in the winery and during the vinifications and to obtain a collection of autochthonous S. cerevisiae strains from this area. Yeast populations from three vats containing fermenting musts from different grape varieties were analysed. Two of them were inoculated with a natural ''pied de cuve'' while the third one was sown with a rehydrated commercial yeast strain. A total of 382 yeasts were isolated and identified, initially by restriction analysis of ribosomal DNA and further by sequencing of this region. Non-Saccharomyces yeasts were found in all three musts but they practically disappeared as the fermentations progressed. Analysis of mitochondrial DNA RFLP revealed 13 different restriction patterns of Saccharomyces cerevisiae strains, five of them similar to those of commercial strains used in the winery. Commercial strains were found even in vats inoculated with a ''pied de cuve'' generated by spontaneous fermentation of a must sample. The analysis of samples recovered from different winery surfaces and equipments demonstrated that nonSaccharomyces and both commercial and autochthonous Saccharomyces strains were part of the resident microflora in the winery. Biodiversity of autochthonous S. cerevisiae in fermentation vats was low but two of them were able to compete with the commercial ones and they were isolated even at the end of the fermentation.

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