Cultivation of Medicinal Caterpillar Fungus, Cordyceps militaris (Ascomycetes), and Production of Cordycepin Using the Spent Medium from Levan Fermentation

A process of tandem cultivation for the production of green and invaluable bioproducts (levan and Cordycepes militaris) useful for medical applications has been successfully developed. The process involves first cultivating Bacillus subtilis strain natto in sucrose medium to produce levan, followed by the subsequent cultivation of C. militaris in liquid- and solid-state cultures using the spent medium from levan fermentation as substrates. The factors affecting the cell growth and production of metabolites of C. militaris were investigated, and the various metabolites produced in the culture filtrate, mycelia, and fruiting body were analyzed. In addition, cordycepin was prepared from the solid waste medium of C. militaris. This is an excellent example in the development of cost effective biorefineries that maximize useful product formation from the available biomass. The preparation of cordycepin from solid waste medium of C. militaris using a method with high extraction efficiency and minimum solvent usage is also environmentally friendly.