Cumin at concentrations of 0.5, 1.0 and 2.0% (w/w) stimulated growth and acid production of Lactobacillus plantarum and Leuconostoc mesenteroides in a liquid medium. Essential oil from cumin at high concentrations (300 and 600 ppm) inhibited growth and acid production of Lactobacillus plantarum. After a certain period, growth of Leuconostoc mesenteroides was observed at all concentrations (150, 300 and 600 ppm) and its acid production was stimulated at 600 ppm. Oregano and its essential oil at all concentrations inhibited growth of both cultures. Acid production by Lactobacillus plantarum was stimulated by oregano spice.