title: Physiological and biochemical properties and morphology of Saccharomyces cerevisiae VKMu-488 cells incorporated into polyacrylamide gel.
abstract: The enzymatic activity, viability, respiratory activity, and ultrastructural changes in saccharomyces cerevisiae VKMu-488 cells, which carry out the stereospecific 17 beta-reduction of methyl esters, was studied. The 17 beta-hydroxysteroid dehydrogenase activity of yeasts in gel is four times lower than that of free cells and is unstable. The decrease in the viability and respiratory activity immediately after immobilization, the disturbance in the ultrastructure of the cells in gel along with the progressive lysis of the cells in the course of the transformation indicate that polymerization has a stressful effect on this culture. It was found that the immobilized yeasts can grow on the surface of the gel in the presence and absence of nutrient medium. A single incubation of granules containing cells in nutrient medium greatly stabilizes the original activity of the immobilized cells. The activation and stabilization of the activity are probably due to the participation of a heterogeneous population in the transformation: the original population incorporated into the gel and the new population which grows in the gel after immobilization as well as to the stability of the ultrastructural organization of this mixed population in the course of repeated transformations of secoketone.
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000178:Acrylamides; D002455:Cell Division; D055598:Chemical Phenomena; D002621:Chemistry; D004963:Estrenes / Q000378:metabolism; D005782:Gels; D008828:Microbiological Techniques; D012441:Saccharomyces cerevisiae / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D012632:Secosteroids / Q000378:metabolism
chemical_list: D000178:Acrylamides; D004963:Estrenes; D005782:Gels; D012632:Secosteroids; D015067:17-Hydroxysteroid Dehydrogenases