Metabolism of starter bacterial cultures used in meat curing processes and sausage fermentation causes decrease in such as nitrate and nitrite and also inhibits production of some the concentration of xenobiotics pathogenic toxins. This is due to the varying composition of starters in which, apart from lactic acid bacteria, some other bacteria such as Micrococcus, Staphylococcus, as well as yeasts and moulds, can be used. Starters used in milk fermentation processes can contribute to the decrease in the amount of pathogenic bacteria, but their composition does not cause decrease in nitrate, nitrite and aflatoxins concentration.