[en] The fungal endophyte Cyanodermella asteris was recently isolated from the medicinal plant Aster tataricus. This fungus produces astin C, a cyclic pentapeptide with anticancer and anti-inflammatory properties. The production of this secondary metabolite was compared in immobilized and planktonic conditions. For immobilized cultures, a stainless steel packing immersed in the culture broth was used as a support. In these conditions, the fungus exclusively grew on the packing, which provides a considerable advantage for astin C recovery and purification. C. asteris metabolism was different according to the culture conditions in terms of substrate consumption rate, cell-growth, and astin C production. Immobilized-cell cultures yielded a 30% increase of astin C production associate to a 39% increase in biomass. The inoculum type as spores rather than hyphae, and a pre-inoculation washing procedure with sodium hydroxide, turned out to be beneficial both for astin C production and fungus development onto the support. Finally, influence of culture parameters such as pH and medium composition, on astin C production was evaluated. With optimized culture conditions, astin C yield was further improved reaching a five times higher final specific yield compared to the value reported with astin C extraction from Aster tataricus (0.89 and 0.16 mg/g respectively).