P. Mayser et al., HYDROLYSIS OF FATTY-ACID ESTERS BY MALASSEZIA-FURFUR - DIFFERENT UTILIZATION DEPENDING ON ALCOHOL MOIETY, Acta dermato-venereologica, 75(2), 1995, pp. 105-109
The lipophilic yeast Malassezia furfur belongs to the resident skin fl
ora but has been implicated in various skin diseases, While topical oi
ly preparations may support its growth, their formulation may be alter
ed by yeast-dependent enzymatic degradation, Different synthetic fatty
acid (mono-)esters used as refatting agents were mixed with 10(4), 10
(5) and 5x10(5) yeasts/mu l, respectively, and incubated at 35 degrees
C for a maximum of 48 h on selective agar for pathogenic fungi (Merck
). The amount and pattern of generated free acids were evaluated by de
nsitometric and gas chromatographic analysis, while yeast density was
determined in a Neubauer chamber. Depending on the inoculum, yeast-dep
endent hydrolysis occurred immediately and was best effected in ethyl
esters, followed by isopropyl esters, whereas hydrolysis of decyl olea
te was only limited, Of the fatty acids released, unsaturated fatty ac
ids were more stimulative to growth than saturated fatty acids; no tox
ic effects were observed. In conclusion, yeast-dependent hydrolysis of
these synthetic fatty acid (mono-)esters was critically dependent on
alcohol moiety, while growth promotion was best effected by unsaturate
d fatty acids. These results may help to improve the compatibility of
topical formulations, especially in seborrheic areas.