In: Appl Microbiol Biotechnol 36:344-351Due to an unfortunate printing error, the genus-species name in the above title was misspelled Lactobacillus lactis instead of Lactococcus lactis.Please note that the title should have been printed as above.

The cell wall-associated proteinase from Lactococcus lactis subsp. cremoris SK11 was partially purified and incubated with alpha s1-casein for various times up to 48 h. Sixteen trifluoroacetic acid-soluble oligopeptide hydrolysis products were identified by determination of the amino acid sequence. Eleven of these oligopeptides originated from the 78-residue sequence comprising the C-terminal region of alpha s1-casein and were present among the products after the first 60 min of digestion. Three oligopeptides from the N-terminal region and two others from the central region of the alpha s1-casein sequence were also present among the early digestion products although in smaller amounts than most of the oligopeptides from the C-terminal region. No clear consensus sequence of amino acid residues surrounding the cleavage sites could be identified.

The cell wall-associated proteinase from Lactococcus lactis subsp. crenwris H2 (isolate number 4409) was released from the cells by treatment with lysozyme, even in the presence of 50 mM calcium chloride. Cell lysis during lysozyme treatment was minimal. The proteinase activity released by lysozyme treatment fractionated on ion-exchange chromatography as three main forms, the molecular masses of which were determined by gel exclusion chromatography and polyacrylamide gel electrophoresis. Two of the enzyme forms released, 137 and 145 kDa, were the same as those released by incubation of cells in calcium-free phosphate buffer. In the * Corresponding author.

The cell envelope-associated proteinases from Lactococcus lactis subsp. cremoris H2 (a P,-type proteinaseproducing strain) and SKII (a P111-type proteinase-producing strain) both actively hydrolyze the K-casein component of bovine milk but with significant differences in the specificity of peptide bond hydrolysis. The peptide bonds Ala-23-Lys-24, Leu-32-Ser-33, Ala-71-Gln-72, Leu-79-Ser-80, Met-95-Ala-96, and Met-106-Ala-107 were cleaved by both proteinase types, although the relative rates of hydrolysis at some of these sites were quite different for the two proteinases. Small histidine-rich peptides were formed as early products of the action of the cell envelope-associated proteinases on K-casein, implicating this casein as a possible significant source of histidine, which is essential for starter growth. The major difference between the two proteinase types in their action on K-casein was in their ability to cleave bonds near the C-terminal end of the molecule. The bond Asn-160-Thr-161 and, to a lesser extent, the bond Glu-151-Val-152 were very rapidly cleaved by the

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