Application of microparticle-enhanced cultivation to increase the access of oxygen to Aspergillus terreus ATCC 20542 mycelium and intensify lovastatin biosynthesis in batch and continuous fed-batch stirred tank bioreactors

Abstract

Microparticle-enhanced cultivation (MPEC) was used in the bioreactor cultivation of lovastatin-producing Aspergillus terreus ATCC 20542. Increasing oxygen saturation of the broth increased lovastatin titer but more important was pellet morphology, in that oxygen reached the fungal cells better in smaller and looser pellets. Thus, we changed pellet size adding 10μm talc microparticles to the preculture. This resulted in 3.5-fold higher lovastatin titer in the subsequent production culture, compared to the control runs (without microparticles), reaching 250mgl−1 in the best continuous fed-batch run. The significant increase of lovastatin titer and low cost of microparticles makes MPEC cultivation for lovastatin production an attractive alternative.