The aim of this study was to assess the potential of lactic acid bacteria to inhibit the outgrowth of some common food-spoiling fungi and bacteria. 40 lactic acid bacteria (LAB) and 20 Bacillus strains isolated from the fermented tomato (Solanum lycopersicum) for their capacity to produce antimicrobial activities against several bacteria and fungi. The strain designed LBc03 has been selected for advanced studies. The supernatant culture of this strain inhibits the growth of Escherichia coli, Staphylococcus aureus and Aspergilus sp. Based on the cultural, morphological, physiological and biochemical characteristics, LBc03 was identified as Leuconeustoc spp. Its antimicrobial compound was determined as a proteinaceous substance, but it is possible that the bacteriocin may also be bound to other molecules like a lipid or a carbohydrate moiety. Metabolite extracts from selected LAB were more effective in preserving tomato paste and sauce stored at 4°C against spoilage bacteria like E. coli and the application of bio-preservative should be encouraged in food processing industries.