Polydimethylsiloxane dispersed in an aqueous emulsion is adsorbed by different yeast strains in varying amounts. Saccharomyces cerevisiae NCYC 366 grows normally in defined medium containing PDS emulsion antifoam. Organisms suspended in PDS supplemented buffer becomes saturated with PDS after 3-4 h.; the adsorption is unaffected by temperature or PH value of the buffer. The respiratory activity of organisms is unchanged by PDS adsorption but the electrophoretic mobility is affected between PH values of 4.0 and 7.0. PDS is released from cells when cells are converted into sphaeroplasts and PDS is adsorbed by isolated cell-walls; the data suggests that the yeast cell-wall is the main site of adsorption.
|Date of Award||1976|