Glycolytic sequence and respiration of Debaryomyces hansenii as compared to Saccharomyces cerevisiae

Abstract

The fermentation and respiration activities of Debaryomyces hansenii were compared with those of Saccharomyces cerevisiae grown to stationary phase with high respiratory activity. It was found that: (a) glucose consumption, fermentation and respiration were lower than for S. cerevisiae; (b) fasting produced a much smaller decrease of respiration; (c) glucose consumed and not transformed to ethanol was higher; (d) in S. cerevisiae, full oxygenation prevented ethanol production but this effect was reversed by CCCP, whereas D. hansenii still showed some ethanol production under aerobiosis, which was moderately increased by CCCP. ATP levels were similar in the two yeasts. Levels of glycolytic intermediaries after glucose addition, and enzyme activities, indicated that the main difference and limiting step to explain the lower fermentation of D. hansenii is phosphofructokinase activity. Respiration and fermentation, which are lower in D. hansenii, compete for the re-oxidation of reduced nicotinamide adenine nucleotides; this competition, in turn, seems to play a role in defining the fermentation rates of the two yeasts. The effect of CCCP on glucose consumption and ethanol production also indicates a role of ADP in both the Pasteur and Crabtree effects in S. cerevisiae but not in D. hansenii. D. hansenii shows an alternative oxidase, which in our experiments did not appear to be coupled to the production of ATP.

High Osmolarity Environments Activate the Mitochondrial Alternative Oxidase in Debaryomyces Hansenii

“…Under our experimental conditions, the growth rate of these cells increases independently of the osmolite present in the media (Fig 2, typical traces are shown in Panels A, quantifications are depicted in Panel B). This result agrees with previous reports [12, 13]. …”

Effects of amiodarone on K+, internal pH and Ca2+homeostasis inSaccharomyces cerevisiae

“…This is a robust strain, showing high fermentation, respiration, proton pumping and ion transport capacities (see for instance Peña et al, 1972;Peña, 1975;Sánchez et al, 2006). This is a robust strain, showing high fermentation, respiration, proton pumping and ion transport capacities (see for instance Peña et al, 1972;Peña, 1975;Sánchez et al, 2006).…”

Biotin Starvation with Adequate Glucose Provision Causes Paradoxical Changes in Fuel Metabolism Gene Expression Similar in Rat (Rattus norvegicus), Nematode (Caenorhabditis elegans) and Yeast (Saccharomyces cerevisiae)

“…The acid extracts were obtained as described previously [19][20][21] . Briefly, approximately 20 mg wet weight of each organism was ground in a nitrogenchilled mortar and collected in perchloric acid solution (0.6 M in 20 m M EDTA).…”