Starter cultures applied in meat technology may contain moulds, yeasts and bacteria. Moulds have been selected with the primary intension to exclude any potential of mycotoxin production. Their sensory effects and the requirements of technology are also criteria for suitable starters. Their genetic potential can now be modified by genetic engineering. Yeasts are applied for sensory reasons mainly. The species in use are only fermentative and do not enhance nitrate reduction. Bacterial components of starters consist of micrococci, staphylococci, lactic acid bacteria (LAB) and with minor importance, Streptomyces griseus or Aeromonas sp. For selection of the appropriate organisms and for ensuring optimum performance in the fermentation process, their technological, ecological, physiological and genetic properties should be well known. Most knowledge is available for LAB, which represent the most important group of starter organisms, since they are involved in the fermentation of all types of products and contribute to each single aim of the fermentation process. The study of the properties of the organisms may also contribute to reduction of potential hygienic risks not only in the classical fields of starter application but also in new fields where they may be employed as protective cultures that inhibit the growth of food pathogens or even spoilage organisms. Strains with an improved potential to reduce these risks and to exhibit further useful properties can be obtained by means of genetic engineering. Examples for successfully modified meat specific bacteria are Staphylococcus carnosus and lactobacilli L. curvatus and L. sake.