ABSTRACT
Lipolysis plays a role in the development of strong flavored cheese, such as blue-veined cheese, which requires free fatty acids for flavor and as substrates for oxidation on methylketones [Khaled et al., 1990]. However, the exact role of lipolysis in flavor development of hard and semi-hard cheeses, such as cheddar and Swiss type cheese, is not well understood. It was suggested that esterases of cheese related bacteria might produce compounds that contribute to cheese flavor during the ripening process. Reports on the esterolytic and lipolytic activities of cheese related microorganisms are available in the literature [El-Soda et al. 1995]. However, little information is available on the purification and characterization of their lipase and esterase systems except for some attempts by Oterholm et al. [1972], Lee and Lee [1990], Tsakalidou and Kalantzopoulos, [1992] and Dupuis and Boy-aval [1993]. Therefore, the objective of the present paper was to purify and characterize the esterase system of Brevibacteriaum linens, Propionibacterium acidipropionici, Bifidobacterium infants, Leuconostoc mesenteroides subsp mesenteroides and Pediococcus sp