It was studied the reduction of a population of Lactobacillus brevis in phosphate buffer by the combination of ultra-high pressure homogenization (UHPH) treatment and the use of lysozyme as antimicrobial. The minimum inhibitory concentration (MIC) of lysozyme against L. brevis was 50 mg.L-1. The observed inhibition was transitory and the growth curve showed that lysozyme addition was able to delay the L. brevis growth for 2 days. Lysozyme added at MIC concentration to a suspension of L. brevis caused a reduction of 1 logarithmic cycle after two hours of contact. The UHPH treatment against L. brevis resulted in a reduction of 7 log cycles at 200 MPa. Lysozyme was resistant to UHPH (200 MPa), without loss of muramidase activity or significant loss of antimicrobial power. A combined treatment was applied using 50 mg.L-1 of lysozyme and pressure between 150 and 170 MPa; the combined effect showed a reduction of about 6 logarithmic cycles and the unaltered count of L.brevis after pressure treatment for a week, with the samples stored at room temperature (25 degrees C). (C) 2007 Elsevier Ltd. All rights reserved.93265271