High-level secretory production of phospholipase A₁ by Saccharomyces cerevisiae and Aspergillus oryzae

Phospholipase A₁ (PLA₁) is a hydrolytic enzyme that catalyzes the removal of the acyl group from position 1 of lecithin to form lysolecithin. The PLA₁ gene, which had been cloned from Aspergillus oryzae, was expressed in Saccharomyces cerevisiae and A. oryzae. Through the modification of the medium composition and the feeding conditions of substrate, the production level of PLA₁ by S. cerevisiae was increased to a level fivefold higher than that indicated in a previous report. In the case of A. oryzae, introduction of multicopies of PLA₁ expression units, and the morphological change from the pellet form to the filamentous form were effective for the enhancement of PLA₁ production. We succeeded in producing 3,500 U/ml of PLA₁ using an industrial-scale fermentor.