Optimized medium for the efficient production of Bacillus intermedius glutamyl endopeptidase by the recombinant Bacillus subtilis strain AJ73

A nutrient medium was elaborated for the efficient production of glutamyl e ndopeptidase by the recombinant Bacillus subtilis strain AJ73 bearing the B acillus intermedius 3-19 glutamyl endopeptidase gene within a multicopy pla smid. Optimal concentrations of the main nutrients, peptone and inorganic p hosphate, were found using a multifactor approach. To provide for active gr owth and efficient glutamyl endopeptidase production, the cultivation mediu m of the recombinant strain should be enriched in phosphorus, organic and i norganic nitrogen sources, and yeast extract. Complex protein substrates, s uch as casein and gelatin, enhanced the biosynthesis of glutamyl endopeptid ase. At the same time, easily metabolizable carbon sources suppressed it. T he production of glutamyl endopeptidase was stimulated by the bivalent cati ons Ca2+, Mg2+, and Co2+.