Characterisation of Micrococcaceae isolated from different varieties of chorizo

A total of 426 strains of Micrococcaceae bacteria isolated from chorizo (a traditional Spanish fermented sausage) were identified. The chorizos were s ampled from three regions of Castilla and Leon in Spain: Burgos, Segovia an d Salamanca. Two factories were chosen in each region and the samples were taken at three stages of ripening. Staphylococcus xylosus was the most pred ominant species isolated (95%). Twelve strain types of S. xylosus were esta blished according to their fermentation patterns, and two of them, S. xylos us type 2 and S. xylosus type 5, made up the majority of the strains of S. xylosus isolated (27 and 52%). Production of acetoin, nitrate reductase, ur ease activity, proteolytic and lipolytic activity were determined for all i solates. The percentage of strains of S. xylosus producing acetoin depends on the manufacturing location. Ln general, the proteolytic and lipolytic ac tivities of the S. xylosus isolated from chorizo from Castilla and Leon wer e low and moderate: 97% of the strains showed nitrate reductase and urease activity. According to our results and to previous investigations, it seems that S. xylosus type 5, showing nitrate reductase and ur ease activity, lo w-moderate proteolytic and lipolytic activities and not producing acetoin w ould be suitable as a starter culture. Of the strains isolated in this stud y, 38% comply with these requirements. (C) 2000 Elsevier Science B.V. All r ights reserved.