Disposable bioreactor for culturing cells in a nutrient medium

A disposable bioreactor (1, 1′) for cultivation of cells in a nutrient medium, comprising a reagent container (2, 2″) having an open upper end (4) that is sealable with a lid (3), the lid (3) being provided with at least one opening (19) that is covered by a membrane (21) for achieving a sterile exchange of air, the container (2, 2″) further having a lower end (8) and a container side wall (6) extending between the upper and lower ends (4, 8), a closed bottom wall (9) at the lower end (8) of the container side wall (6), the reagent container (2, 2″) being subjectable to a shaking operation in a shaking apparatus, the container side wall (6) having a substantially cylindrical inner surface extending from the open upper end (4) to the lower end (8), the cylindrical inner surface (7, 7′, 7″) being interrupted only by a baffle (10, 10′, 14, 14′) consisting of as a single continuous uninterrupted web extending helically from a lower position in proximity to the lower end (8) to an upper position in proximity to the open upper end (4), the web (10, 14) having a cross-section with a convex curvature (11) directed away from the inner surface (7, 7′, 7″) of the container wall (6) and configured as an elliptical, parabolic or circular section to avoid sharp edges that can impair cell division and damage cells.