Esterase activity in Candida species

The purpose of this investigation was to ascertain the lipolytic activities (specifically, esterase) of those species of Candida that are most commonly isolated from human infections. Eight species of Candida were surveyed for their ability to hydrolyze various polyoxyethylene sorbitan compounds (Tweens). Of the 64 isolates tested, each had activity for at least one of the substrates. Most of the isolates hydrolyzed Tweens 40, 60, and 85. In contrast, none hydrolyzed Tween 80. Only one species hydrolyzed Tween 20. The patterns of precipitation resulting from reactions of fatty acids hydrolyzed from Tweens 40, 60, and 85 with calcium ions in the media were also useful in distinguishing some of the species. In the past, such reactions have been reported as being dependent on esterase activity.