Browsing by Subject "Candida utilis"

Now showing 1 - 3 of 3
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    Caracterización de la inulinasa e invertasa en Candida utilis
    (Universidad de Murcia, Servicio de Publicaciones, 1985) Argüelles Ordóñez, Juan Carlos; Gacto Fernández, Mariano José; Ros Espín, Rosa María; Facultad de Biología
    lnvertase (E.C. 3.2.1.26) and inulinase (E.C. 3.2.1. 7) were analyzed in Candida utilis CECT 1061 to determine whether one single enzyme with both activities or two enzymes with different substrate specificities were present in this yeast. The synthesis of both fructofuranosidase activities was under control of catabolite repression by glucose and they were present in whole cell extracts as well as in the extracellular culture fluids. The cell-associated activities appear mostly located in the periplasmic space. The two activities exhíbited an identical optimum pH and similar profiles of thermal denaturation. In addition, a constan! ratio was found between the inulinase and the invertase activities in a variety of culture condítions when extracellular media or cell extracts were assayed. From the results obtained it was concluded that both activities reside in a same protein of molecular weight close to 450,000 dalton which shows a different affiníty for sucrose and inuline, Km values were 14 and 0,62mM. respectively.
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    Effect of trehalose and other compounds on the resistance to desiccation by Candida utilis cells
    (Murcia: Universidad de Murcia, Servicio de Publicaciones, 1987) Lapeña, M.A.; Pardo, C.; Gacto Fernández, Mariano José; Facultad de Biología
    As other yeasts, Candida utilis intracellularly accumulates trehalose as reserve carbohydrate. Stationary-phase cells show higher resistance to the loss of viability by desiccation than log-phase cells when subjected to a lyophilization protocol. This finding correlates with the fact that resting cells contain higher levels of endogenous trehalose than exponentially growing cells. The number of resulting viable cells can be increased by addition of exogenous trehalose inmediately before the desiccation treatment. These results suggest a protective role for trehalose in addition to the previously assumed of serving as energy source. The comparison of the protective effect of trehalose on cell death by dehydration to that developped by other compounds indicates that such a role is neither exclusive of this sugar nor dependent of its nonreducing character. Other disaccharides and glycerol can be even more effective in preventing loss of viability by desiccation. However, taking into account that trehalose is the only disaccharide endogenously accumulated, the physiological significance of this effect appears to be relevant.
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    Light-induced rhythmic changes in thermotolerance in stationary-phase cells of Candida utilis
    (International microbiology : the official journal of the Spanish Society for Microbiology., 2006) Lapeña, Miguel A.; Vicente, Jero; Soto, Teresa; Madrid, Marisa; Núñez, Andrés; García, Encarnación; Cansado Vizoso, José; Gacto, Mariano; Genética y Microbiología
    In synchronized light-dark cycles, stationary-phase cultures of the budding yeast Candida utilis were able to survive heat treatment at 50ºC with an apparent circadian-like rhythm related to the onset of light. However, in continuous darkness this pattern did not run freely and was markedly dampened. We discuss these findings in terms of the potential circadian control of heat tolerance, which has been described in the fission yeast Schizosaccharomyces pombe. Our results suggest that the resistance pattern observed in C. utilis is most likely an adaptive response to the light-induced generation of reactive oxygen species rather than the occurrence of a truly endogenous circadian rhythm