Process for producing extracellular proteins in bacteria

A method for producing an extracellular protein in a bacterium, the method comprising

• (a) transforming cells of a bacterium having an inner and outer cell membrane with a recombinant vector including a DNA construct comprising a DNA sequence encoding a fusion protein, wherein said fusion protein comprises an N-terminal prepropeptide, but not a C-terminal propeptide, of Achromobacter lyticus protease I, corresponding to residues 1-205 of SEQ ID NO:27, fused to a polypeptide sequence comprising a desired protein;
• (b) culturing the transformed cells of step (a) under conditions permitting expression of the fusion protein;
• and
• (c) recovering the fusion protein, the desired protein, or both from the medium.

A method for producing an extracellular protein in a bacterium, the method comprising

• (a) transforming cells of a bacterium having an inner and outer cell membrane with a recombinant vector including a DNA construct comprising a DNA sequence encoding a fusion protein, wherein said fusion protein comprises an N-terminal prepropeptide, but not a C-terminal propeptide, of Achromobacter lyticus protease I, corresponding to residues 1-205 of SEQ ID NO:27, fused to a desired protein;
• (b) culturing the transformed cells of step (a) under conditions permitting expression of the fusion protein and leakage of the fusion protein through transport out of the cell either by secretion across both the inner and outer cell membrane, or by export of the protein to the periplasm followed by partial lysis of the outer membrane, or release from the outer membrane into the culture medium;
• and
• (c) recovering the resulting fusion protein, desired protein, or both from the medium.