Antimicrobial activity of lactic acid bacteria isolated from Tenerife cheese: initial characterization of plantaricin TF711, a bacteriocin-like substance produced by Lactobacillus plantarum TF711

Aims: The screening and initial characterization of bacteriocins produced by lactic acid bacteria ( LAB) from raw Tenerife goats' cheese with possible application as biopreservatives or ripening accelerators for Tenerife cheese. Methods and Results: One hundred and eighty LAB of the genera Lactobacillus ( 95), Leuconostoc ( 64) and Lactococcus ( 21) isolated from raw Tenerife goats' cheese were screened for the production of antimicrobial substances. Lactobacillus plantarum TF711, which had the broadest spectrum of antimicrobial activity, was selected for further characterization. The antimicrobial compound was determined as a proteinaceous substance, as it was sensitive to proteases. The bacteriocin- like substance, which we called plantaricin TF711, was active against the Gram- positive bacteria Bacillus cereus, Clostridium sporogenes and Staphylococcus aureus; and against the Enterobacteriaceae Shigella sonnei and Klebsiella pneumoniae. It was stable to heat and to treatment with surfactants and organic solvents. Highest antimicrobial activity was found between pH 1 and 9. Plantaricin TF711 exhibited primary metabolite kinetics, a bacteriostatic mode of action and a molecular mass of c. 2.5 kDa as determined by tricine SDS- PAGE. Conclusions: Lact. plantarum TF711 produces a low molecular mass bacteriocin- like compound with a wide spectrum of activity and interesting technological properties ( thermostability, good pH stability and stability against surfactants and organic solvents). Significance and Impact of the Study: Plantaricin TF711 was found to have potential for use as a biopreservative in the food industry.