Comparison of selective media for the recovery and enumeration of probiotic yeasts from animal feed

Six selective media (acidified malt extract agar, CHROMagar Candida, dichloran rose bengal chloramphenicol, molybdate, oxytetracycline glucose yeast extract and Petrifilm Yeast and Mould agar) were examined for the recovery of three yeasts commonly used in animal feeds as probiotic additives (Candida pintolopesii, C. saitoana and Saccharomyces cerevisiae). The highest recovery was obtained on oxytetracycline glucose yeast extract agar, although this was susceptible to overgrowth by moulds. CHROMagar Candida also gave good recovery and species were easily discriminated by the differential colour formation of colonies.