Secretion of outer membrane proteins of gram-negative bacteria by means of gram-positive host organisms

Process for producing outer membrane protein of Gram-negative bacteria recoverable from the culture supernatant, from Gram-positive host cells in which a gene structure is constructed which has an outer membrane protein coding gene from Gram-negative bacteria as well as a propeptide coding progene sequence for an export protein of a Gram-positive bacterium upstream of this outer membrane protein coding gene, and a pregene sequence coding for a signal peptide of an export protein of a Gram-positive bacterium upstream of the progene sequence, the gene structure is cloned in a vector and this is transformed in a Gram-positive bacteria as a host cell having substantially no protease activity in the culture supernatant, whereafter the Gram negative outer membrane protein is expressed as a fusion protein with the Gram positive signal peptide and the Gram positive propeptide, is transported through the membrane of the Gram-positive host cell and is liberated in the culture supernatant.