This study aimed to partially purify and characterise the bacteriocin produced by Leuconostoc mesenteroides A11 and to evaluate the bacteriocin production in whey at different concentrations and temperatures (30 and 25°C). The partially purified bacteriocin was obtained by chromatography and analysed by electrophoresis. Thus, the molecular weight of the bacteriocin was estimated by electrophoresis, ranging from 3.5 to 8.5 kDa. Leu conostoc mesenteroides A11 produced bacteriocins in all concentrations of whey and temperatures evaluated, indicating that it would be feasible to employ low whey concentrations and room temperature for the production of bacteriocins, thereby reducing processing costs.