Nine bacterial strains grew at 50 degrees C on a mineral medium containing Tween 80 as sole carbon source and three of them produced significant lipolytic activities. The strains showed optimal growth at 50 degrees C and thus, they are moderate thermophiles. Lipolytic activity were maxima at 57-67 degrees C suggesting high thermostability. Lipolytic activity production was promoted by the addition of Tween 80 in culture medium and inhibited by glucose addition. These strains are convenient sources of thermostable lipolytic enzymes for biotechnological applications.