In this study we uncovered that Saccharomyces cerevisiae UOFS Y-2330 does not only demonstrate inverse flocculation, but is also characterised by two different lipid turnover patterns. During Flo1 phenotype flocculation, this yeast showed two neutral lipid accumulating stages (i.e. at 8 h and from 12 h). This is probably triggered by flocculation, which can be regarded as a survival mechanism where cells accumulate predominantly neutral lipids as a reserve energy source -a similar mechanism is probably operative when cells enter stationary growth. Contrary to Flo1 behaviour, this strain in NewFlo phenotype mode demonstrates only a single lipid accumulation phase i.e. when cells enter stationary growth, which coincides with increase in flocculation. In addition, an increase in phospholipids was experienced during active growth in both flocculation behaviours i.e. Flo1 and NewFlo probably as a result of active membrane production.

No abstract

No abstract

SummaryElectroformed nickel tubing was deactivated by chemical vapor deposition of silicon from silane gas and subsequent treatment with cyclooctamethyltetrasiloxane (D4). Standard activity tests performed on the uncoated tube and also on columns coated with crosslinked and uncrosslinked, nonpolar stationary phase, show that good quality flexible columns can be prepared from nickel tubing. The inner surface of the silicon coated tube was characterized by Auger depth profile analysis.

SummaryA sampling system for high resolution gas-liquid chromatography, based on the dynamic solvent effect, is described. Volatiles areaccumulated off -line in a concentrator/injector and delivered to the column using an on-line inlet. Volatiles may be accumulated from gaseous or liquid matrices; they may be transferred to these by gas sparging or solvent extraction of any type of sample. The sampling technique is quantitatively precise; e.g. coefficients of variation of peak percentage areas betterthan5Yofora rangeof solutesat aconcentrationof 2:lO'.Examples of the application of the sampling system are presented.