Search results for " Saccharomyces"
showing 10 items of 42 documents
Utilizzo del pied de cuve fortificato per la fermentazione spontanea di vini rossi di qualità
2018
La fermentazione spontanea è un processo biologico incontrollato durante il quale molti lieviti e/o batteri potrebbero aumentare rapidamente in concentrazioni tali incidere negativamente sulla qualità del prodotto finale. A tal proposito, al fine di ottimizzare la crescita di lieviti con buone attitudini enologiche, si utilizza il metodo “pied de cuve”. Questa tecnica enologica è in grado di realizzare in una determinata massa di mosto dal volume ridotto, una fermentazione alcolica con un ceppo di lievito opportunamente inoculato o con ceppi di lieviti indigeni, naturalmente presenti nel mosto. Al fine di valorizzazione ed aumentare la diffusione di pratiche enologiche basate su un ridotto …
Genome Characterization of natural Saccharomyces hybrids of biotechnological interest
2012
At present, the genus Saccharomyces comprises seven species according to their patterns of breeding. The species boundaries are not clear due to the description of several reticulate events due to introgression and hybridization. In the last decade, new natural hybrids have been described in wine and brewing, such as S. cerevisiae x S. kudriavzevii. Due to new practices in wine and beer production, together with consequences in grape properties due to climatic change, led biotechnological companies to search for new yeast strains. In this context, hybrids have become of importance to biotechnological industries because they show good fermentative performance at low temperatures and produce …
Investigation of yeast community of “Grillo” grapes and musts from Marsala wine production area.
2009
The oenological interest in the autochthonous yeast applications has increased since they represents an important supplement to wine quality (Martinez et al. 1989; Moreno et al. 1991). Yeast populations harboured onto the surface of berries and in musts of “Grillo” grape variety were isolated and analyzed. In order to obtain a first blastomycetic mapping of Marsala wine production area, eight vineyards were chosen on the basis of different climatic and agronomic parameters, including altitude, exposure,vineyard age, grape biotype, grape cultivation system, vegetative vigour, pruning, green pruning, yield per plant, phytosanity state, irrigation and closeness to wood areas. Analysis of blast…
Wine yeast sirtuins and Gcn5p control aging and metabolism in a natural growth medium.
2012
Grape juice fermentation by wine yeast is an interesting model to understand aging under conditions closer to those in nature. Grape juice is rich in sugars and, unlike laboratory conditions, the limiting factor for yeast growth is nitrogen. We tested the effect of deleting sirtuins and several acetyltransferases to find that the role of many of these proteins during grape juice fermentation is the opposite to that under standard laboratory aging conditions using synthetic complete media. For instance, . SIR2 deletion extends maximum chronological lifespan in wine yeasts grown under laboratory conditions, but shortens it in winemaking. Deletions of sirtuin . HST2 and acetyltransferase . GCN…
Microbial resources and sparkling wine differentiation : state of the arts
2022
Consumers’ increasing interest in sparkling wine has enhanced the global market’s demand. The pro-technological yeasts strains selected for the formulation of microbial starter cultures are a fundamental parameter for exalting the quality and safety of the final product. Nowadays, the management of the employed microbial resource is highly requested by stakeholders, because of the increasing economic importance of this oenological sector. Here, we report an overview of the production processes of sparkling wine and the main characterisation criteria to select Saccharomyces and non-Saccharomyces strains appropriate for the preparation of commercial starter cultures dedicated to the primary a…
Genetic identification of neurons controlling a sexually dimorphic behaviour
2000
0960-9822 (Print) Journal Article Research Support, Non-U.S. Gov't; In the fruit fly Drosophila melanogaster, locomotor activity is sexually dimorphic: female flies constantly modulate their activity pattern whereas males show a steadier, stereotyped walking pace [1]. Here, we mapped the area of the brain controlling this behavioural dimorphism. Adult male Drosophila expressing a dominant feminising transgene in a small cluster of neurons in the pars intercerebralis exhibited a female-like pattern of locomotor activity. Genetic ablation of these neurons prevented the feminisation of the locomotor activity of transgenic males. The results suggest that this cluster of neurons modulates sex-sp…
PARTIAL SEQUENCING OF THE BETA-GLUCOSIDASE-ENCODING GENE FROM YEAST STRAINS ISOLATED FROM MUSTS AND WINES
2008
The aim of the present work was the identification of the gene encoding for β-glucosidase and its partial sequencing in the strainsPichia anomala AL112,Hanseniaspora uvarum Y8 andSaccharomyces cerevisiae AL41. To this aim degenerated primers, designed on the basis of aminoacid similarities of four known yeast β-glucosidases, have been used in PCR amplifications. An expected fragment of about 200 bp was amplified from all the DNAs, cloned and sequenced. Sequence homology demonstrated for the first time the presence of a β-glucosidase encoding gene inHanseniaspora uvarum andSaccharomyces cerevisiae.
AcetyltransferaseSAS2and sirtuinSIR2,respectively, control flocculation and biofilm formation in wine yeast
2014
Cell-to-cell and cell-to-environment interactions of microorganisms are of substantial relevance for their biotechnological use. In the yeast Saccharomyces cerevisiae, flocculation can be an advantage to clarify final liquid products after fermentation, and biofilm formation may be relevant for the encapsulation of strains of interest. The adhesion properties of wine yeast strains can be modified by the genetic manipulation of transcriptional regulatory proteins, such as histone deacetylases, and acetylases. Sirtuin SIR2 is essential for the formation of mat structures, a kind of biofilm that requires the expression of cell-wall protein FLO11 as its deletion reduces FLO11 expression, and ad…
Mitochondrial inheritance and fermentative : oxidative balance in hybrids between Saccharomyces cerevisiae and Saccharomyces uvarum.
2008
Breeding between Saccharomyces species is a useful tool for obtaining improved wine yeast strains, combining fermentative features of parental species. In this work, 25 artificial Saccharomyces cerevisiae × Saccharomyces uvarum hybrids were constructed by spore conjugation. A multi-locus PCR‐restriction fragment length polymorphism (PCR‐RFLP) analysis, targeting six nuclear gene markers and the ribosomal region including the 5.8S rRNA gene and the two internal transcribed spacers, showed that the hybrid genome is the result of two chromosome sets, one coming from S. cerevisiae and the other from S. uvarum. Mitochondrial DNA (mtDNA) typing showed uniparental inheritance in all hybrids. Furth…
A Metagenomic-Based Approach for the Characterization of Bacterial Diversity Associated with Spontaneous Malolactic Fermentations in Wine
2019
This study reports the first application of a next generation sequencing (NGS) analysis. The analysis was designed to monitor the effect of the management of microbial resources associated with alcoholic fermentation on spontaneous malolactic consortium. Together with the analysis of 16S rRNA genes from the metagenome, we monitored the principal parameters linked to MLF (e.g., malic and lactic acid concentration, pH). We encompass seven dissimilar concrete practices to manage microorganisms associated with alcoholic fermentation: Un-inoculated must (UM), pied-de-cuve (PdC), Saccharomyces cerevisiae (SC), S. cerevisiae and Torulaspora delbrueckii co-inoculated and sequentially inoculated, as…