Biofilm development of Candida boidinii and the effect of tyrosol on biofilm formation

Abstract

Objectives: The applicability of a simple and high-throughput method for quantitative characterization of biofilm formation by Candida boidinii was tested in order to evaluate the effects of exogenous tyrosol on yeast growth and biofilm formation capacity.

Results: Significant concentration-, temperature and time-dependent effect of tyrosol (2-(4-hydroxyphenyl)ethanol) was demonstrated, but it differentially affected the growth and biofilm formation (characterized by crystal violet staining and XTT-reduction assay) of Candida boidinii. Testing biofilm based on metabolic activity displayed sensitively the differences in the intensity of biofilm in terms of temperature, tyrosol concentration, and exposure time. At 22 °C after 24 h none of the tyrosol concentrations had significant effect, while at 30 °C tyrosol-mediated inhibition was observed at 50 mM and 100 mM concentration. After 48 h and 72 h at 22 °C, biofilm formation was stimulated at 6.25-25 mM concentrations, meanwhile at 30 °C tyrosol decreased the biofilm metabolic activity proportionally with the concentration.

Conclusions: The research concludes that exogenous tyrosol exerts unusual effects on Candida boidinii growth and biofilm formation ability and predicts its potential application as a regulating factor of various fermentations by Candida boidinii.

Keywords: Biofilm formation; Candida boidinii; Quorum sensing; Tyrosol.

Fig. 1

Growth of Candida boidinii in three different media at 22 °C (a), 30 °C (b) and 37 °C (c), data represent averages of five replicates

Fig. 2

Biofilm formation of Candida boidinii in three different media at 22 °C (a), 30 °C (b) and 37 °C (c), data represent averages of five replicates

Fig. 3

Effect of increasing tyrosol concentration on microbial growth at 22 °C (a), 30 °C (b) and 37 °C (c), data represent averages of five replicates

Fig. 4

Effect of increasing tyrosol concentration on CV-stained biofilm formation at 22 °C (a) and 30 °C (b), data represent averages of five replicates

Fig. 5

Effect of increasing tyrosol concentration on relative biofilm formation at 22 °C, data represent averages of five replicates

Fig. 6

Summary of tyrosol concentration-, contact time- and temperature-dependent effects on the growth (total and planktonic cell density) and the biofilm formation of C. boidinii

Fig. 7

Effect of increasing tyrosol concentration on the biofilm metabolic activity determined by XTT-assay at 22 °C (a) and 30 °C (b), data represent averages of five replicates