Glucose fed-batch integrated dissolved oxygen control strategy enhanced polysaccharide, total triterpenoids and inotodiol production in fermentation of a newly isolated Inonotus obliquus strain

Submerged fermentation is promising for producing secondary metabolites of Inonotus obliquus, a folk medicine to treat cancer and other diseases. However, there limited progress work in strain selection or process optimization in order to enhance production of its bioactive metabolites. In this work, a new Inonotus obliquus strain was isolated from the sclerotia collected in Belarus, which was identified by ITS sequencing and phylogenetic analysis. The dissolved oxygen (DO) condition was optimized, it showed that 50% DO level facilitated secondary metabolites production. Finally, a glucose fed-batch integrated DO control strategy was developed by feeding 10 g/L glucose when residual sugar decreased to 10 g/L, while controlling DO level at 50%. The biomass, polysaccharide, triterpenoids and inotodiol production enhanced by 52%, 31%, 54% and 65%, respectively. This study demonstrated that the new strain shown good fermentation property. Glucose fed-batch integrated DO control strategy effectively enhanced secondary metabolites production in fermentation of Inonotus obliquus.