Isolation of potential starter strains from spontaneously fermented Swiss raw sausages.

23 spontaneously fermented raw sausages of different types and from different Swiss regions were used for the isolation of 122 isolates of lactic acid bacteria and 19 strains of staphylococci, which corresponded well with the species used in commercial meat starter cultures. A large variation was found in the tested technological characteristics like growth and acidification, effect of nitrate and nitrite on growth, nitrite degradation (all for lactic acid bacteria) and nitrate reductase activity (for staphylococci) for the isolates from the spontaneously fermented raw sausages. They also covered isolates which were comparable with those from the commercial starter cultures. Some L. curvatus and L. sakei strains degraded much more nitrite than the other lactic acid bacteria strains, whereas four staphylococci strains (including a commercial one) showed no nitrate-reductase activity. It was concluded from the present study that the used technological characteristics are suitable for strain selection for the development of future meat starter cultures. However, additional properties like aroma, bacteriocin production, antibiotic resistance, reduction of biogenic amines and aptitude for lyophilisation have to be considered before the definitive introduction of such meat starter cultures.