Abstract: The production of recombinant chymosin is disclosed in which an insoluble form of chymosin precursor is produced by a bacterial host cell transformed by a vector including a coding sequence for said precursor. Solubilization of said insoluble form of chymosin precursor is accomplished using urea at a concentration of at least 7M or guanidine hydrochloride at a concentration of at least 6M prior to cleaving said precursor to form chymosin. Said solubilization preferably additionally involves the denaturation of said precursor in an alkaline aqueous solution, e.g., at a pH between a 9 and 11.

Abstract: A DNA molecule comprising a nucleotide sequence substantially corresponding to all or a portion of foot and mouth disease virus RNA and in particular coding for at least one protein of foot and mouth disease virus. The DNA molecule can be inserted into a DNA cloning vehicle capable of expressing the DNA molecule, after a suitable host cell has been transformed by the cloning vehicle. The expression product can be incorporated into a vaccine for stimulating antibodies against FMDV. Methods for producing the DNA molecule, recombinant cloning vehicle and transformed host cell are described.