1,720,982 research outputs found
L’acido gluconico e l’acido lattico come indici di qualità microbiologica dei succhi d’arancia
No full textL’acido gluconico e l’acido lattico come indici di qualità microbiologica dei succhi d’aranci
Electrophoretic Profile of Thermotolerant Saccaromyces cerevisiae
No full textElectrophoretic Profile of Thermotolerant Saccaromyces cerevisia
Inheritance of mitochondrial DNA in interspecific Saccharomyces hybrids
No full textSpore conjugation between Saccharomyces cerevisiae and S. uvarum strains yields hybrids which have mitochondria of only a parental type: either of S. cerevisiae or S. uvarum. The peculiarity of examined hybrids is due to the homogeneity of their clone populations that are consisting of cells, all characterised by the same mitochondrial type. It seems to be probable to suppose an incompatibility of parental mitochondrial DNA (mtDNA).Spore conjugation between Saccharomyces cerevisiae and S. uvarum strains yields hybrids which have mitochondria of only a parental type: either of 5. cerevisiae or S. uvarum. The peculiarity of examined hybrids is due to the homogeneity of their clone populations that are consisting of cells, all characterised by the same mitochondrial type. It seems to be probable to suppose an incompatibility of parental mitochondrial DNA (mtDNA)
Karyotiping of Saccharomyces strains with different temperature profiles
No full textThis study examined the, the fermentation performance and the optimum growth temperature (Topt) of 28yeast strains all identified as species belonging to Saccharomyces sensu stricto. The strainswere isolated from fermented musts, which had not been inoculated, at twotemperature ranges: 20–40 °C and approximately 0–6 °C. The results demonstrated acorrelation between the Topt and the chromosome organization. In particular, strains withTopt of less than 30 °C showed only two bands in the region between 365 and 225 kb,while those with a Topt greater than 30 °C had three bands in this size range. From ataxonomic viewpoint, the Topt is a better indicator for the Saccharomyces sp. than theceiling temperature of 37 °C currently used to differentiate cryotolerantSaccharomyces bayanus and S. pastorianus from non-cryotolerant S. cerevisiae and S.paradoxus strains
Electroforetic profiles of hybrids between cryotolerant and non-cryotolerant Saccharomyces strains
No full textThe chromosomal DNAs of cryotolerant Saccharomyces bayanus, non-cryotolerant Saccharomyces cerevisiae strains and their intra and interspecific hybrids were separated by pulsed field electrophoresis (PFGE). The cryotolerant and non-cryotolerant strains gave distinctly different electrophoretic profiles. The hybrids cryotolerant x cryotolerant and non-cryotolerant x non-cryotolerant were fertile and they gave the same electrophoretic karyotype as the respective parents. The cryotolerant x non-cryotolerant hybrids were sterile and gave electrophoretic karyotypes which showed both the bands the parents have in common and those they do not share
A b-glucosidase positive strain of Saccharomyces cerevisiae isolated from grape must
No full textA b-glucosidase positive strain of Saccharomyces cerevisiae isolated from grape mus
Cryotolerant Saccharomyces strains and spoilage of refrigerated musts
No full textThis study regards yeasts isolated from refrigerated musts with patent ongoing fermentation. The isolates belonged to the genus Saccharomyces sensu stricto with an optimal growth temperature less than 30 degrees C. Karyotype analysis highlighted the constant presence of two well-defined trait bands in the low molecular weight between 225 and 375 kb that distinguished them unequivocally from normal Saccharomyces cerevisiae strains. The isolated strains individually reinoculated in sterile must at 25 degrees C, produce complete fermentation. Analysis of minor fermentation compounds revealed other differences between these strains and Saccharomyces cerevisiae strains. These strains are responsible for the spoilage of fermenting refrigerated must. Phenotype traits, combined with karyotype, suggest that they should not be assigned to Saccharomyces cerevisiae but more reasonably to Saccharomyces bayanus uvarum type
Characterization of acetic acid bacteria in traditional balsamic vinegar
No full textThis study evaluated the glucose tolerance of acetic acid bacteria strains isolated from Traditional Balsamic Vinegar. The results showed that the greatest hurdle to acetic acid bacteria growth is the high sugar concentration, since the majority of the isolated strains are inhibited by 25% of glucose. Sugar tolerance is an important technological trait because Traditional Balsamic Vinegar is made with concentrated cooked must. On the contrary, ethanol concentration of the cooked and fermented must is less significant for acetic acid bacteria growth. A tentative identification of the isolated strains was done by 16S-23S-5S rDNA PCR/RFLP technique and the isolated strains were clustered: 32 strains belong to Gluconacetobacter xylinus group, two strains to Acetobacter pasteurianus group and one to Acetobacter aceti
Il governo dell'acidità titolabile e reale dei vini meridionali con mezzi biologici.
No full textIl governo dell'acidità titolabile e reale dei vini meridionali con mezzi biologici
Valutazione della biodiversità di ceppi di batteri lattici isolati da olive siciliane fermentate al naturale.
No full textValutazione della biodiversità di ceppi di batteri lattici isolati da olive siciliane fermentate al naturale
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