Search results for "Hanse"
showing 7 items of 47 documents
Rational selection of non-Saccharomyces wine yeasts for mixed starters based on ester formation and enological traits
2008
Thirty-eight yeast strains belonging to the genera Candida, Hanseniaspora, Pichia, Torulaspora and Zygosaccharomyces were screened for ester formation on synthetic microbiological medium. The genera Hanseniaspora and Pichia stood out as the best acetate ester producers. Based on the ester profile Hanseniaspora guilliermondii 11027 and 11102, Hanseniaspora osmophila 1471 and Pichia membranifaciens 10113 and 10550 were selected for further characterization of enological traits. When growing on must H. osmophila 1471, which displayed a glucophilic nature and was able to consume more than 90% of initial must sugars, produced levels of acetic acid, medium chain fatty acids and ethyl acetate, wit…
Killer toxin-secreting double-stranded RNA mycoviruses in the yeasts Hanseniaspora uvarum and Zygosaccharomyces bailii.
1994
Killer toxin-secreting strains of the yeasts Hanseniaspora uvarum and Zygosaccharomyces bailii were shown to contain linear double-stranded RNAs (dsRNAs) that persist within the cytoplasm of the infected host cell as encapsidated virus-like particles. In both yeasts, L- and M-dsRNAs were associated with 85-kDa major capsid protein, whereas the additional Z-dsRNA (2.8 kb), present only in the wild-type Z. bailii killer strain, was capsid protein, whereas the additional Z-dsRNA (2.8 kb), present only in the wild-type Z. bailii killer strain, was shown to be encapsidated by a 35-kDa coat protein. Although Northern (RNA) blot hybridizations indicated that L-dsRNA from Z. bailii is a LA species,…
Exoenzymes of Wine Microorganisms
2008
The production of wine from grape juice is predominantly the result of enzymatic reactions. The enzymes originate from the grape itself, from epiphytic fungi like Botrytis cinerea colonizing the grape surface and finally from yeasts and bacteria growing in the must until termination of alcoholic fermentation. Especially nonSaccharomyces yeasts, also called “wild” yeasts, belonging to the genera Kloeckera, Candida, Debaryomyces, Rhodotorula, Pichia, Zygosaccharomyces, Hanseniaspora, Kluyveromyces, and Metschnikowia produce and secrete several enzymes (esterases, glycosidases, lipases, glucanases, proteases, cellulases, etc.) to the periplasmatic space and the medium where they may interact w…
Dehydration of yeast: Changes in the intracellular content of Hsp70 family proteins
2008
Abstract Yeast is known to experience in natural and industrial conditions cycles of dehydration–rehydration. Several molecular mechanisms can be triggered in response to this and other environmental stressors and to rescue yeast cells of the cytotoxic effect. Since heat shock proteins constitute one of the most important systems of the response to stress we studied whether the pre-induced major stress protein, Hsp70, can cope with yeast cell drying. To induce Hsp70 expression the cells of two yeast species, Saccharomyces cerevisiae and Debaryomyces hansenii , were subjected to non-lethal heat shock. It was found that during yeast culture growth Hsp70 accumulation occurred at the exponentia…
Dairy Debaryomyces hansenii strains produce the antihypertensive casein-derived peptides LHLPLP and HLPLP
2015
The ability of dairy Debaryomyces hansenii, Kluyveromyces lactis and Kluyveromyces marxianus strains to release the casein-derived antihypertensive sequences RYLGY, AYFYPEL, LHLPLP, HLPLP, VPP and/or IPP was examined. Yeast strains were grown in medium with casein as sole nitrogen source and the yeast casein hydrolysates (CSHs) were analysed by HPLC-MS/MS to search for the six antihypertensive sequences. Only LHLPLP and HLPLP were identified in CSHs and exclusively in D. hansenii Dh1 and Dh14 hydrolysates in which both antihypertensive sequences represented approximately 6 (CSH Dh1) and 10% (CSH Dh14) of total peptide content. In addition, a complete analysis of selected CSHs by HPLC-MS/MS …
Biotechnological characterisation of exocellular proteases produced by enologicalHanseniasporaisolates
2014
Summary Twenty-six enological Hanseniaspora isolates were identified by ITS PCR-RFLP and D1/D2 domain of 26S rDNA sequencing and assayed for exocellular protease production. Based on qualitative data, six isolates, belonging to H. guilliermondii, H. valbyensis and H. occidentalis species, were selected to continue the study. Analytical procedure was optimised, and protease activities were quantified and characterised on the basis of different biotechnological factors. Protease activity was quite glucose, fructose and ethanol content independent, but divalent cation affects activity; these data support that they were aspartic proteases. The effect of 2-mercaptoethanol suggests the importance…
Biotechnological innovations in fermentation process of brewing and honey-based beverages industry
2022
La ricerca di microrganismi fermentanti in grado di migliorare le proprietà microbiologiche, fisiche, chimiche, sensoriali e organolettiche delle bevande alcoliche fermentate come vino, birra, idromele, sidro, è considerata ad oggi un punto chiave per lo sviluppo del settore. Negli ultimi anni, l'aumento della domanda al consumo di nuove bevande fermentate ha causato un enorme bisogno di tecnologie di produzione innovative al fine di ottenere diverse tipologie di prodotti caratterizzati da proprietà sensoriali peculiari. Per raggiungere tale obiettivo, l’impiego di nuovi microrganismi, sia fermentanti che non fermentanti, in grado di conferire al prodotto caratteristiche organolettiche pecu…