Headspace - SPME as a screening system for yeast metabolic compounds: a case study

Abstract

Aim: This study aimed to identify and quantify the fusel alcohols secreted by the opportunistic yeasts Candida albicans and Candida dubliniensis to further get insights into the amino acid catabolism of those two organisms. Methods and Results: Fusel alcohols were screened in cell - free supernatants of yeasts cultivated in RPMI medium. For simultaneous identification and quantification of these alcohols, a Headspace - Solid Phase Micro Extraction (HS - SPME) coupled with gas chromatography - mass spectrometry (GC - MS) methodology, previously developed to analyse the volatile composition of fruits, was followed (Coelho et al. 2006). Results obtained show that both C. albicans and C. dubliniensis produced isoamyl alcohol and 2- phenylethanol, end – products of the catabolism of the amino acids leucine and phenylalanine, respectively. Significance and Impact of the study: The HS – SPME used herein allows the simultaneous identification and quantification of compounds, requires small sample volume, has high sensitivity and reproducibility, is simple and rapid and is solvent free. This revealed to be a powerful tool for the screening system of yeast metabolic compounds.