[Producers of mycophenolic acid in ensiled and grain feeds].

Using the reaction of activated N-hydrooxisuccinimide ester of mycophenolic acid, a series of immunoreactive conjugated antigens with albumins, gelatin, and glucosoxidase is obtained. On the basis of polyclonal rabbit antibodies, a test-system for indirect competitive immunoenzyme analysis is elaborated, which has the sensitivity 0.4 ng/ml. By immunoanalysis, the ability for active biosynthesis of mycophenolic acid in strains of Byssochlamys nivea (44/44, 4100-68400 ng/ml) and Penicillium roqueforti (7/16, 204-25120 ng/ml) from the mycobiota of ensiled feeds is confirmed. The correspondence between weakly expressed producing capacity of most species of fungi of the genera Penicillium and Aspergillus prevailing in grain feeds and the data on low occurrence of this metabolite in grain (8.0%) and combined feeds (11.9%) is confirmed. A potential relationship between particular cases of a significant accumulation of mycophenolic acid (from 500 to 1500 microg/kg) in grains of wheat, corn, and combined feeds and a high biosynthetic activity in rare species P. puberulum, P. stoloniferum, and P. gladioli is discussed.