R. Tsuboi et al., INDUCTION OF AN EXTRACELLULAR ESTERASE FROM CANDIDA-ALBICANS AND SOMEOF ITS PROPERTIES, Infection and immunity, 64(8), 1996, pp. 2936-2940
As extracellular esterase from Candida albicans A-714 was found to be
induced in a medium containing 0.7% yeast nitrogen base and 2.5% Tween
80 (polyoxyethylenesorbitan compounds). Enzyme activity, which exists
predominantly in the extracellular space, was measured by a colorimet
ric method using alpha-naphthyl palmitate as a substrate. The inductio
n level of the esterase activity was found to be well correlated with
fungal growth and was dependent on the Tween 80 concentration. Such es
terase activity was observed only in medium containing Tween 80 or oth
er Tweens as the sole carbon source and therefore was not observed in
either peptone-glucose medium or peptone-glucose medium supplemented w
ith Tween 80. The induced esterase was heat labile and had maximum act
ivity at pH 5.5. Enzyme activity was stimulated by the addition of sod
ium taurocholate, an activator of lipase. Thin-layer chromatography re
vealed that this enzyme does not hydrolyze triolein and L-alpha-lecith
in, suggesting that it is a monoester hydrolase (not a lipase in the s
trict sense of the word). Esterase activity was examined in 85 clinica
l isolates of Candida species; C. albicans, C. tropicalis, and C. para
psilosis tended to have higher enzyme activities than C. kefyr, C. kru
sei, C. glabrata, and C. guilliermondii. Although the physiological pr
operties of this exterase are not clear at present, it was found to be
crucial for fungal growth under specific conditions.