The proposition of an inexpensive chemically defined culture medium (MycoDef) for yeast studies

Abstract

Chemically defined culture media (CDCMs) have their compositions qualitatively and quantitatively known. They are constituted of components able to meet the nutritional requirements of microorganisms. This study evaluated the employability of a multivitamin as the basis for the elaboration of a CDCM for experiments with yeasts. Candida albicans reference strains ATCC®90028™ and SC5314 were used. YNB® without amino acid (Difco Co.) was used as the standard in evaluations. For the preparation of the experimental culture medium (MycoDef), commercial multivitamin tablets had their coatings removed and were crushed until obtaining a fine powder; missing constituents were added. Comparisons were carried out evaluating aerobic and anaerobic planktonic growth rate, biofilm formation rate, whole-cell protein patterns by SDS-PAGE, minimum inhibitory concentrations and minimal fungicidal concentrations for clotrimazole, fluconazole, nystatin, and griseofulvin. Growth in MycoDef and YNB® did not differ between them (p>0.05) in both normoxic and anoxic conditions. Regarding employability for sensitivity testing, MycoDef showed performance like YNB®. The protein profiles of cells grown on both media did not differ in the number and positioning of bands. The results obtained allowed us to infer that MycoDef is a reliable low-cost culture medium useful for trials involving C. albicans.