Cloning, expression, chromosomal stabilization of the propionibacterium shermanii proline iminopeptidase gene (pip) for food-grade application in lactococcus lactis - Bolhuis, Albert.; Boot, Johan.; Deutz, Inge.; Kok, Jan.; Ledeboer, Aat.; Leenhouts, Kees.; Toonen, Marjolein.; Venema, Gerard.