# Characteristics of Candida albicans metabolism of glucose and two sugar substitutes, xylose and xylitol and effect of these substitutes on glucose metabolism from a cariogenic perspective

## TL;DR

This study explores how Candida albicans metabolizes glucose, xylose, and xylitol, finding that glucose supports more growth and acid production than the sugar substitutes.

## Contribution

The study provides new insights into the metabolic pathways of C. albicans when using xylose and xylitol, and their impact on glucose metabolism.

## Key findings

- C. albicans grows and produces less acid on xylose and xylitol compared to glucose.
- Glucose metabolism primarily yields ethanol and carbon dioxide under aerobic conditions.
- Xylose and xylitol do not inhibit glucose metabolism in C. albicans.

## Abstract

Carbohydrate metabolism and subsequent acid production of Candida albicans remain insufficiently understood. C. albicans may utilize xylitol, but its cariogenic implications are understudied. This study examined growth and metabolism of glucose, xylitol and precursor xylose by C. albicans and their effects on glucose metabolism.

C. albicans JCM1537 was cultured in YNB medium containing 1% glucose, xylose, xylitol or xylose- or xylitol-glucose combinations. Acid production from cells grown on each substrate was assessed by pH-stat system at pH 7.0 using 10 mM substrates. Metabolic end-products were quantified by HPLC and enzymatic methods. Carbon recovery and redox balance of glucose metabolism were calculated stoichiometrically.

Growth and acid production on xylose or xylitol were much lower than on glucose, with no inhibitory effect of xylose or xylitol observed. Glucose carbon was distributed as 50.48% ethanol, 21.95–24.72% bicarbonate, 5.70% glycerol, 2.88% organic acids and 0.12% acetaldehyde, yielding 81.07–84.48% recovery and 93.26–93.97% reduction–oxidation balance.

Although xylose and xylitol did not inhibit C. albicans glucose metabolism, their limited growth and acidogenicity suggest low cariogenic potential. The overall view of glucose metabolism, including high ethanol production, provides new insights into the metabolic impact of C. albicans within the oral microbiome.

Candida
albicans was able to metabolize xylitol and its precursor xylose; however, rates of growth and acid production were lower than on glucose.Xylose and xylitol did not inhibit glucose metabolism in Candida
albicans.Under aerobic conditions, and with an abundance of glucose, Candida
albicans converts most of the consumed glucose into ethanol and carbon dioxide, and some into organic acids.

Candida
albicans was able to metabolize xylitol and its precursor xylose; however, rates of growth and acid production were lower than on glucose.

Xylose and xylitol did not inhibit glucose metabolism in Candida
albicans.

Under aerobic conditions, and with an abundance of glucose, Candida
albicans converts most of the consumed glucose into ethanol and carbon dioxide, and some into organic acids.