1,721,028 research outputs found
Discrimination between Candida albicans and other pathogenic species of the genus Candida by their differential sensitivity to toxins of a panel of killer yeasts
No full textA genomic approach to analyze the cold adaptation of yeasts isolated from Italian Alps
No full textMicroorganisms including yeasts are responsible for mineralization of organic matter in cold regions, and their characterization is critical to elucidate the ecology of such environments on Earth. Strategies developed by yeasts to survive in cold environments have been increasingly studied in the last years and applied to different biotechnological applications, but their knowledge is still limited. Microbial adaptations to cold include the synthesis of cryoprotective compounds, as well as the presence of a high number of genes encoding the synthesis of proteins/enzymes characterized by a reduced proline content and highly flexible and large catalytic active sites. This study is a comparative genomic study on the adaptations of yeasts isolated from the Italian Alps, considering their growth kinetics. The optimal temperature for growth (OTG), growth rate (Gr), and draft genome sizes considerably varied (OTG, 10°C–20°C; Gr, 0.071–0.0726; genomes, 20.7–21.5 Mpb; %GC, 50.9–61.5). A direct relationship was observed between calculated protein flexibilities and OTG, but not for Gr. Putative genes encoding for cold stress response were found, as well as high numbers of genes encoding for general, oxidative, and osmotic stresses. The cold response genes found in the studied yeasts play roles in cell membrane adaptation, compatible solute accumulation, RNA structure changes, and protein folding, i.e., dihydrolipoamide dehydrogenase, glycogen synthase, omega-6 fatty acid, stearoyl-CoA desaturase, ATP-dependent RNA helicase, and elongation of very-long-chain fatty acids. A redundancy for several putative genes was found, higher for P-loop containing nucleoside triphosphate hydrolase, alpha/beta hydrolase, armadillo repeat-containing proteins, and the major facilitator superfamily protein. Hundreds of thousands of small open reading frames (SmORFs) were found in all studied yeasts, especially in Phenoliferia glacialis. Gene clusters encoding for the synthesis of secondary metabolites such as terpene, non-ribosomal peptide, and type III polyketide were predicted in four, three, and two studied yeasts, respectively
Application of anhydrobiosis and dehydration of yeasts for non-conventional biotechnological goals
No full textDehydration of yeast cells causes them to enter a state of anhydrobiosis in which their metabolism is temporarily and reversibly suspended. This unique state among organisms is currently used in the production of active dry yeasts, mainly used in baking and winemaking. In recent decades non-conventional applications of yeast dehydration have been proposed for various modern biotechnologies. This mini-review briefly summarises current information on the application of dry yeasts in traditional and innovative fields. It has been shown that dry yeast preparations can be used for the efficient protection, purification and bioremediation of the environment from heavy metals. The high sorption activity of dehydrated yeasts can be used as an interesting tool in winemaking due to their effects on quality and taste. Dry yeasts are also used in agricultural animal feed. Another interesting application of yeast dehydration is as an additional stage in new methods for the stable immobilisation of microorganisms, especially in cases when biotechnologically important strains have no affinity with the carrier. Such immobilisation methods also provide a new approach for the successful conservation of yeast strains that are very sensitive to dehydration. In addition, the application of dehydration procedures opens up new possibilities for the use of yeast as a model system. Separate sections of this review also discuss possible uses of dry yeasts in biocontrol, bioprotection and biotransformations, in analytical methods as well as in some other areas
Psychrophilic yeasts from worldwide glacial habitats: diversity, adaptation strategies and biotechnological potential
No full textGlacial habitats (cryosphere) include some of the largest unexplored and
extreme biospheres on Earth. These habitats harbor a wide diversity of psychrophilic
prokaryotic and eukaryotic microorganisms. These highly specialized
microorganisms have developed adaptation strategies to overcome the direct
and indirect life-endangering influence of low temperatures. For many years
Antarctica has been the geographic area preferred by microbiologists for studying
the diversity of psychrophilic microorganisms (including yeasts). However,
there have been an increasing number of studies on psychrophilic yeasts sharing
the non-Antarctic cryosphere. The present paper provides an overview of
the distribution and adaptation strategies of psychrophilic yeasts worldwide.
Attention is also focused on their biotechnological potential, especially on their
exploitation as a source of cold-active enzymes and for bioremediation purposes
First outbreak of bovine mastitis caused by Prototheca blaschkeae
No full textThe most important animal disease caused by yeast-like algae belonging to the genus
Prototheca is bovine mastitis. Although the infection can be caused by both Prototheca
zopfii genotype 2 and Prototheca blaschkeae, the bulk of prevalence of bovine protothecal
mastitis has been so far attributed to the former, being P. blaschkeae only sporadically
isolated. However, we report here the first outbreak of bovine mastitis caused by P.
blaschkeae in an Italian dairy herd. One hundred and four individual milk samples, three
bulk tank milk and 16 environmental samples within the herd were screened for the
presence of Prototheca: five, one and four positive samples, were respectively observed.
Molecular analysis revealed that, with the sole exception of one environmental isolate
belonging to P. zopfii genotype 2, all Prototheca strains were identified as P. blaschkeae.
Our results might suggest that even P. blaschkeae can induce mastitis outbreaks, while it
is not clear if the higher incidence of P. zopfii genotype 2 as causative agent of protothecal
mastitis could reflect an intrinsic higher pathogenicity or it could be simply the
consequence of its, so far observed, higher diffusion in worldwide dairy herd ecosystems
In vitro antimycotic activity of galloyl-derivatives extracted from leaves of Camellia sinensis towards yeast and yeast-like strains. XXII Int. Conference on Polyphenols.
No full textDynamics of organic matter and microbial populations in amended soil: a multidisciplinary approach
No full textSynthesis of pyrogalloyl esters-methylglucosides and evaluation of antioxidant and antimycotic activity - XXII Int. Conference on Polyphenols.
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