Detection and preliminary characterization of a bacteriocin (plantaricin 35d) produced by a Lactobacillus plantarum strain

Lactic acid bacteria (134) from Italian sausages were tested for the produc tion of antimicrobial substances (bacteriocins). Six percent of these showe d antibacterial activity against one or several closely related microorgani sms used as indicators. Lactobacillus plantarum 35d in particular produced a bacteriocin of high activity (320 AU ml(-1)) and a wide range of antimicr obial activity including S. aureus. L. monocytogenes, and A. hydrophila. Th e bacteriocin withstood heating at 80 degreesC for 120 min and storage at 4 degreesC for 6 months. The mode of action was identified as bactericidal. The apparent molecular weight of the bacteriocin extracted with n-butanol w as estimated to be 4.5 kDa. (C) 2001 Elsevier Science B.V. All rights reser ved.