In this study we screened a number of isolates of LAB from olives with the aim of selecting those showing antimicrobial activity against A. acidoterrestris sp1. 50 potential LAB isolates were obtained from the olive homogenate plated on MRS plates. Single colonies were streaked onto fresh MRS plates and overlaid with L. lactis HP. Only one out of the 50 tested colonies exhibited a zone of inhibition against the indicator strain. A CFS of this strain produced an inhibitory zone against A. acidoterrestris sp1 on an ADT, confirming that this isolate produces an extracellular antimicrobial compound against A. acidoterrestris sp1. This colony was identified as Lb. plantarum by 16S rDNA sequencing and designated Lb. plantarum NI326. No zone of inhibition was apparent when the CFS was first treated with proteinase K confirming the proteinaceous nature of the antimicrobial compound (data not shown).