High level expression of Fusarium alkaline protease gene in Acremonium chrysogenum

We transformed Acremonium chrysogenum with the genomic DNA of the alkaline protease (Alp) from Fusarium sp. S-19-5 including its promoter. Most of the transformants thus obtained produced a large amount of Alp. PCR and Southern hybridization analysis of genomic DNAs from these transformants showed chromosomal integration of the full-length Alp gene. SDS-PAGE analysis of the supernatant from the transformants showed the presence of Fusarium Alp. The amino terminus of the Alp produced in A. chrysogenum was identical to that of native Fusarium Alp. These results indicate that the Alp promoter, signal sequence, and introns functioned correctly in A. chrysogenum. One of the transformants produced more than 4 g of the Alp per liter in a jar fermentor.