Influence of invertase activity and glycerol synthesis and retention on fermentation of media with a high sugar concentration by Saccharomyces cerevisiae.

Starmerella bacillaris (synonym Candida zemplinina) is an important non-Saccharomyces yeast in winemaking with valuable oenological properties, accompanying Saccharomyces species in sweet wine fermentation, and has also been suggested for application as combined starter culture in dry or sweet wines. In this study, the major metabolites and nitrogen utilization of these yeasts are evaluated in the musts with high or extremely high sugar concentration. The change in the metabolic footprint of Saccharomyces cerevisiae, Saccharomyces uvarum and Starmerella bacillaris strains was compared when they were present as pure cultures in chemically defined grape juice medium with 220 and 320 g/L of sugar, to represent a fully matured and an overripe grape. Surprisingly, the extreme sugar concentration did not result in a considerable change in the rate of sugar consumption; only a shift of the sugar consumption curves could be noticed for all species, especially for Starmerella bacillaris. At the extreme sugar concentration, Starmerella bacillaris showed excellent glycerol production, moderate nitrogen demand together with a noticeable proline utilisation. The change in the overall metabolite pattern of Starmerella bacillaris allowed clear discrimination from the change of the Saccharomyces species. In this experiment, the adequacy of this non-Saccharomyces yeast for co-fermentation in juices with high sugar concentration is highlighted. Moreover, the results suggest that Starmerella bacillaris has a more active adaptation mechanism to extremely high sugar concentration.

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Hyperosmotic stress response by strains of bakers' yeasts in high sugar concentration medium

Letters in Applied Microbiology ◽

10.1046/j.1472-765x.2000.00825.x ◽

2000 ◽

Vol 31 (4) ◽

pp. 323-327 ◽

Cited By ~ 34

Author(s):

P.V. Attfield ◽

S. Kletsas

Keyword(s):

Stress Response ◽

Hyperosmotic Stress ◽

Sugar Concentration ◽

High Sugar Concentration ◽

High Sugar

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Model-assisted analysis of the peach pedicel–fruit system suggests regulation of sugar uptake and a water-saving strategy

Journal of Experimental Botany ◽

10.1093/jxb/eraa103 ◽

2020 ◽

Vol 71 (12) ◽

pp. 3463-3474

Author(s):

Dario Constantinescu ◽

Gilles Vercambre ◽

Michel Génard

Keyword(s):

Sugar Transport ◽

Water Saving ◽

Lower Pressure ◽

Sugar Concentration ◽

Sugar Uptake ◽

Pressure Potential ◽

High Sugar Concentration ◽

High Sugar ◽

Diurnal Patterns ◽

Assisted Analysis

Abstract We develop a model based on the biophysical representation of water and sugar flows between the pedicel, fruit xylem and phloem, and the fruit apoplast and symplast in order to identify diurnal patterns of transport in the pedicel–fruit system of peach. The model predicts that during the night water is mainly imported to the fruit through the xylem, and that fruit phloem–xylem transfer of water allows sugar concentrations in the phloem to be higher in the fruit than in the pedicel. This results in relatively high sugar transport to the fruit apoplast, leading to relatively high sugar uptake by the fruit symplast despite low sugar concentrations in the pedicel. At midday, the model predicts a xylem backflow of water driven by a lower pressure potential in the xylem than in the fruit apoplast. In addition, fruit xylem-to-phloem transfer of water decreases the fruit phloem sugar concentration, resulting in moderate sugar uptake by the fruit symplast, despite the high sugar concentration in the pedicel. Globally, the predicted fruit xylem–phloem water transfers buffer the sugar concentrations in the fruit phloem and apoplast, leading to a diurnally regulated uptake of sugar. A possible fruit xylem-to-apoplast recirculation of water through the fruit phloem reduces water lost by xylem backflow at midday.

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Enamel Demineralization by Snack Foods

Journal of Dental Research ◽

10.1177/00220345750540030801 ◽

1975 ◽

Vol 54 (3) ◽

pp. 461-470 ◽

Cited By ~ 34

Author(s):

B.G. Bibby ◽

S.A. Mundorff

Keyword(s):

Sugar Content ◽

Sugar Concentration ◽

Bacterial Fermentation ◽

Snack Foods ◽

High Sugar Concentration ◽

High Sugar ◽

Enamel Demineralization

The amount of enamel destroyed by salivary fermentation of snack foods and confections was not dependent on their sugar content; starch, flavoring agents, and other components also played a part. Most enamel destruction was produced by fruit-flavored candies in which the inherent acid or high sugar concentration or both inhibited bacterial fermentation.

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