The technological characteristics of Debaryomyces hansenii and Yarrowia lipolytica and their potential as starter cultures for production of Danablu

Six strains of Debaryomyces hansenii var. hansenii and Yarrowia lipolytica, respectively, originating from blue mould cheeses were examined for their potential use as starter cultures for the production of Danablu in laboratory studies. D. hansenii showed strong growth and assimilation of lactose, galactose, lactate and five out of six strains assimilated citric acid under the environmental conditions prevailing in Danablu during maturation at 10°C. Y. lipolytica was more sensitive to NaCl and did not assimilate lactose and galactose. Both yeasts hydrolysed tributyrin with the highest activity observed for Y. lipolytica. D. hansenii showed little if any release of free fatty acids from butterfat at 10°C. Y. lipolytica was strongly lipolytic. The strains of D. hansenii were not able to hydrolyse casein at 10°C whereas 4 of the 6 strains of Y. lipolytica degraded all components of the casein. Strain-specific interactions, in cheese agar resulting in inhibition of mycelial growth and sporulation of P. roqueforti was observed, especially for Y. lipolytica.