An Enzymic Analysis of NADPH Production and Consumption in Candida utilis

Bruinenberg, P.M.; Dijken, Johannes P. van; Scheffers, W. A.

doi:10.1099/00221287-129-4-965

Cited by 142 publications

(121 citation statements)

References 7 publications

(7 reference statements)

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“…A second solution to this redox imbalance would be to convert NADH into NADPH with a transhydrogenase. However, no such enzymes have been discovered in yeasts (Blank et al 2005;Bruinenberg et al 1983b) and introduction of a heterologous transhydrogenase in S. cerevisiae has demonstrated that in vivo conditions favour NADPH production (Nissen et al 2001).…”

Section: Xylose Fermentationmentioning

confidence: 99%

Alcoholic fermentation of carbon sources in biomass hydrolysates by Saccharomyces cerevisiae: current status

Maris

Abbott

Bellissimi

et al. 2006

Antonie van Leeuwenhoek

436

276

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Fuel ethanol production from plant biomass hydrolysates by Saccharomyces cerevisiae is of great economic and environmental significance. This paper reviews the current status with respect to alcoholic fermentation of the main plant biomass-derived monosaccharides by this yeast. Wild-type S. cerevisiae strains readily ferment glucose, mannose and fructose via the Embden-Meyerhof pathway of glycolysis, while galactose is fermented via the Leloir pathway. Construction of yeast strains that efficiently convert other potentially fermentable substrates in plant biomass hydrolysates into ethanol is a major challenge in metabolic engineering. The most abundant of these compounds is xylose. Recent metabolic and evolutionary engineering studies on S. cerevisiae strains that express a fungal xylose isomerase have enabled the rapid and efficient anaerobic fermentation of this pentose.L-Arabinose fermentation, based on the expression of a prokaryotic pathway in S. cerevisiae, has also been established, but needs further optimization before it can be considered for industrial implementation. In addition to these already investigated strategies, possible approaches for metabolic engineering of galacturonic acid and rhamnose fermentation by S. cerevisiae are discussed. An emerging and major challenge is to achieve the rapid transition from proof-of-principle experiments under 'academic' conditions (synthetic media, single substrates or simple substrate mixtures, absence of toxic inhibitors) towards efficient conversion of complex industrial substrate mixtures that contain synergistically acting inhibitors.

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Section: Xylose Fermentationmentioning

confidence: 99%

Alcoholic fermentation of carbon sources in biomass hydrolysates by Saccharomyces cerevisiae: current status

Maris

Abbott

Bellissimi

et al. 2006

Antonie van Leeuwenhoek

436

276

View full text Add to dashboard Cite

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“…Under anaerobic conditions, it can be assumed that all lipid in biomass is formed from oleic acid in the medium. For the lipid composition under aerobic conditions, a simplification has been made according to Bruinenberg et al (1983), in that all lipid is assumed to be in the form of triglycerides with three long-chain neutral fatty acids; i.e. : palmitoleic acid 13.7; linoleic acid 5.5; oleic acid 8.2; and glycerol 9 mmol-100g cells -I.…”

Section: Calculations Of Theoretical Energy Requirements For Biomass mentioning

confidence: 99%

“…The yield can then be calculated. The reducing equivalents required for ATP production originate from two sources: Firstly, a net production of NADH and/or FADH is obtained in the overall anabolic reactions of most carbon sources commonly employed for yeast growth (Bruinenberg et al 1983;Gommers et al 1988). The assimilation equation for the production of 100 g biomass of S. cerevisiae 8066, including glucose required for the formation of NADPH (as calculated according to Verduyn et al 1990a), is given by: 55 775 C6H120 6 + 540 NH3---~ 1000 C3,75H6.602.18N0.54 (100 g biomass) + 902 CO: + 1426 NADH + 735 H20…”

Section: Calculation Of P/o-ratios For Growth On Glucosementioning

confidence: 99%

“…In these calculations it is assumed that NADPH is provided via NADP-acetaldehyde reductase, which is present at high activities during growth of yeasts on ethanol (Bruinenberg et al 1983) so that involvement of the hexose monophosphate pathway for the production of NADPH is not required. It is furthermore assumed that NADPH-production via this route is exactly balanced with consumption, i.e.…”

Section: Growth Yields On Two-carbon Compoundsmentioning

confidence: 99%

See 1 more Smart Citation

A theoretical evaluation of growth yields of yeasts

Verduyn

Stouthamer

Scheffers

et al. 1991

Antonie van Leeuwenhoek

216

176

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Growth yields of Saccharomyces cerevisiae and Candida utilis in carbon-limited chemostat cultures were evaluated. The yields on ethanol and acetate were much lower in S. cerevisiae, in line with earlier reports that site I phosphorylation is absent in this yeast. However, during aerobic growth on glucose both organisms had the same cell yield. This can be attributed to two factors: -S. cerevisiae had a lower protein content than C. utilis; -uptake of glucose by C. utilis requires energy whereas in S. cerevisiae it occurs via facilitated diffusion. Theoretical calculations showed that, as a result of these two factors, the ATP requirement for biomass formation in C. utilis is 35% higher than in S. cerevisiae (theoretical YATP values of 20.8 and 28.1, respectively). The experimental YATP for anaerobic growth of S. cerevisiae on glucose was 16 g biomass-mol ATP -1.In vivo P/O-ratios can be calculated for aerobic growth on ethanol and acetate, provided that the gap between the theoretical and experimental ATP requirements as observed for growth on glucose is taken into account. This was done in two ways: -via the assumption that the gap is independent of the growth substrate (i.e. a fixed amount of ATP bridges the difference between the theoretical and experimental values). -alternatively, on the assumption that the difference is a fraction of the total ATP expenditure, that is dependent on the substrate. Calculations of P/O-ratios for growth of both yeasts on glucose, ethanol, and acetate made clear that only by assuming a fixed difference between theoretical and experimental ATP requirements, the P/O-ratios are more or less independent of the growth substrate. These P/O-ratios are approximately 30% lower than the calculated mechanistic values.

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“…The pH was controlled by automatic addition of 2 M-KOH. The medium was prepared according to Bruinenberg et al (1983). The organism was grown under glucose limitation (S, 5 g 1-l) with ammonium as the nitrogen source, or under ammonium limitation ( S , 0-4 g 1-l) with glucose as the carbon source (S, 5 g l-l), or under glutamate limitation (carbon limitation without ammonium) ( S , 5 g P I ) .…”

Section: E T H O D Smentioning

confidence: 99%

Adaptation of the Kinetics of Glucose Transport to Environmental Conditions in the Yeast Candida utilis CBS 621: a Continuous-culture Study

Postma¹,

Scheffers²,

Dijken³

1988

Microbiology

Self Cite

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~~~ ~The relation between the kinetic parameters of glucose transport and the physiology of Candida utilis CBS 621 was studied in chemostat cultures. In glucose-limited cultures the transport parameters were dependent on the growth rate of the yeast. Three different transport systems were found which differed by an order of magnitude in their affinity constants, namely a highaffinity ( K , 25 p~), a medium-affinity ( K , 190 p~), and a low-affinity uptake system ( K , 2000 p~). Cells growing at a dilution rate of 0.45 h-l or less had the high-and medium-affinity uptake systems. At a dilution rate of 0.52 h-I the high-affinity system was absent and both the mediumand low-affinity systems were present. At a dilution rate close to pmax (0.57 h-l) only the lowaffinity system was detected. The in situ contribution of each of the transport systems to glucose consumption in glucose-limited cultures was estimated on the basis of their kinetic parameters ( K , and V,,,,,) and the residual glucose concentration in these cultures. The sum of the calculated rates of transport corresponded to the in situ rate of glucose consumption by the cultures as determined from the yield constant and the dilution rate. The dependence of the transport parameters on the growth rate and hence on the environmental sugar concentration was also evident in cells grown under nitrogen limitation. In contrast to carbon-limited cells, nitrogenlimited cultures growing at D = 0.15 h-' did not exhibit the high-affinity glucose uptake system, whereas the medium-and low-affinity systems were present.

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An Enzymic Analysis of NADPH Production and Consumption in Candida utilis

Cited by 142 publications

References 7 publications

Alcoholic fermentation of carbon sources in biomass hydrolysates by Saccharomyces cerevisiae: current status

Alcoholic fermentation of carbon sources in biomass hydrolysates by Saccharomyces cerevisiae: current status

A theoretical evaluation of growth yields of yeasts

Adaptation of the Kinetics of Glucose Transport to Environmental Conditions in the Yeast Candida utilis CBS 621: a Continuous-culture Study

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