STABLE EXPRESSION OF THE LYSOSTAPHIN GENE IN MEAT LACTOBACILLI BY INTRODUCING DELETIONS WITHIN THE PROSEQUENCE

The lys gene of Staphylococcus simulans encoding preprolysostaphin was cloned into Lactobacillus curvatus and Lactobacillus sake. For stable expression of the gene and its maintenance in the host, it was requir ed to delete parts of the repetitive sequences in the region coding fo r the prosequence. The various clones expressing different deletion de rivatives of lys produced bacteriolytic activity which induced lysis o f growing as well as heat inactivated staphylococcal cells. Lysostaphi n iras released into the medium as a truncated proenzyme which was pro cessed to multiple species of active proteins of different molecular m asses including the mature lysostaphin. The number of these forms corr elated with the number of repeats remaining in the various proenzymes.