Optimization of submerged culture conditions for the production of angiotensin converting enzyme inhibitor from Flammulina velutipes.

The angiotensin-converting enzyme (ACE) inhibitory effect was tested in the culture broth from submerged mycelial cultures of 20 basidiomycetes. The ACE inhibitory effect of culture broth from Flammulina velutipes strain 414 was the highest (52.8%), followed by Lentinus edodes strains 2 (44.4%) and 16 (41.3%). Nutritional requirements for the production of ACE inhibitory substance from F. velutipes were studied. Sucrose, ammonium acetate, and glutamic acid were chosen for the maximum production of ACE inhibitory substance. The optimal medium composition was (g/l): sucrose 20, ammonium acetate 5, glutamic acid 2, KH(2)PO(4) 3, MgSO(4).7H(2)O 0.8, and yeast extract 0.5. Under optimal culture conditions, the ACE inhibitory effect was more than 80%.