The stirring device, in particular for a fluid-mixing bioreactor, comprises a drive shaft including a rod, an agitating element and a sleeve of tubular shape. The sleeve forms a coupling sleeve receiving the shaft therethrough and is directly rotationally coupled to the rod. The agitating element, which has a hub with an annular side wall delimiting an inner space and an impeller assembly comprising blades, is indirectly rotationally coupled to the rod via the sleeve that is engaged in the inner space. One of an inner surface of the wall and an outer surface of the sleeve is a guiding surface with progressively reduced cross section. Axial movement between the hub and the sleeve is prevented in a locked configuration of a sleeve fastening arrangement. Hub-sleeve contact areas can be axially distributed.

A bioreactor can include a vessel defining an interior volume; a motor; a rotatable shaft assembly connected to the motor and extending within the interior volume along a longitudinal axis; one or more toroidal impellers mounted onto the shaft assembly and disposed within the interior volume, the toroidal impeller including a plurality of blade members supported by a hub that each define a radially bounded passageway extending along a second axis disposed at an oblique angle to the longitudinal axis.

A bioreactor can include a vessel defining an interior volume; a motor; a rotatable shaft assembly connected to the motor and extending within the interior volume along a longitudinal axis; one or more toroidal impellers mounted onto the shaft assembly and disposed within the interior volume, the toroidal impeller including a plurality of blade members supported by a hub that each define a radially bounded passageway extending along a second axis disposed at an oblique angle to the longitudinal axis.

A sparger assembly (700) for a bioprocessing system includes a base plate (710) and at least one aeration manifold (712, 714) removably connected to tire base plate. Each aeration manifold includes at least one inlet for receiving a gas and a plurality of gas outlet openings for delivering tire gas to a fluid within the bioprocessing system. An impeller assembly (740) fora bioprocessing system includes a hub and at least one blade (742) operatively connected to the hub. The at least one blade includes a first portion connected to the hub and extending generally vertically, and a second portion extending at an upward angle from tire first portion.

A sparger assembly (700) for a bioprocessing system includes a base plate (710) and at least one aeration manifold (712, 714) removably connected to tire base plate. Each aeration manifold includes at least one inlet for receiving a gas and a plurality of gas outlet openings for delivering tire gas to a fluid within the bioprocessing system. An impeller assembly (740) fora bioprocessing system includes a hub and at least one blade (742) operatively connected to the hub. The at least one blade includes a first portion connected to the hub and extending generally vertically, and a second portion extending at an upward angle from tire first portion.