Antimicrobial activity of selected lactic acid cocci and production of organic acids

Antimicrobial activity and production of organic acids by selected lactic acid bacteria were monitored in this study. The largest antimicrobial activity against indicator microorganisms showed Pediococcus sp. G5, whereas Streptococcus thermophilus had no inhibitory effect. The inhibitory effect of Pediococcus sp. G5 was strongest against Bacillus subtilis (17.78 %). Lactococci inhibited the growth of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus (% of inhibition ≤ 5.25). The growth of Asperglillus flavus, Penicillium funiculosum and Rhizopus oryzae was not inhibited by all of tested cocci. Cocci produced varying quantities of organic acids (lactic acid, acetic acid, succinic acid, etc.). Lactic acid was in large amounts and phenyllactic acid was produced only by Pediococcus sp. G5 (49.65 mg/L).