Drug Development from Natural Fermentation Products: Establishing a Manufacturing Process Which Maximizes the Potential of Microorganisms

Abstract

Natural fermentation products have long been studied as attractive targets for drug discovery due to their amazing diverse, complex chemical structures and biological activities. As such, a number of revolutionary drugs developed from natural fermentation products have contributed to global human health. To commercialize a drug derived from natural fermentation products, an effective chemical entity must be identified and thoroughly researched, and an effective manufacturing process to prepare a commercial supply must be developed. To construct such a manufacturing process for tacrolimus and micafungin, the following studies were conducted: first, we focused on controlling the production of the tacrolimus-related compound FR900525, a fermentation by-product of tacrolimus which was critical for quality assurance of the drug substance. FR900525 production was reduced by using a mutant strain which produced more pipecolic acid, the biosynthesis material of tacrolimus, than the original strain. Then, to optimize the fermentation process of FR901379, an intermediate of micafungin, a fed-batch culture was adopted to increase FR901379 productivity. Additionally, FULLZONE(TM) impeller was installed into the scaled-up fermenter, reducing the agitation-induced damage to the mycelium. As a result, the mycelial form changed from filamentous to pellet-shaped, and the air uptake rate during fermentation was drastically improved. Finally, we conducted screening for FR901379 acylase-producing microorganisms, as FR901379 acylase is necessary to manufacture micafungin. We were able to easily discover FR901379 acylase-producing microorganisms in soil samples using our novel, convenient screening method, which involves comparing the difference in antibiotic activity between FR901379 and its deacylated product.