It is a temporary immersion bioreactor (10) for in vitro production of differentiated plant biomass comprising a culture chamber (12) having one or more transparent sidewalls (14) and a mesh bottom (16). that the mesh bottom (16) defines a plurality of pores (18) for receiving the plant material. the bioreactor (10) includes a flexible pouch (20) formed of a transparent material, the flexible pouch (20) having a sealable opening and being sized to receive the culture chamber (12) together with a liquid medium (22) . the bioreactor (10) also includes an outer chamber (24) having one or more transparent sidewalls (26). the outer chamber (24) is formed to have a shape corresponding to the culture chamber (12) and sized to receive the culture chamber (12) into the flexible pouch (20) so that the mesh bottom (16) of the culture chamber culture (12) turns to a bottom (28) of the outer chamber (24) which, in use, is intended to rest on a support surface. movement of the culture chamber (12) within the outer chamber (24) is restricted to movement along a single geometric axis so that the mesh bottom (16) of the culture chamber (12) moves toward the bottom (28) and away from the outer chamber (24). the bioreactor (10) further includes a drive mechanism (30) arranged to selectively drive movement of the culture chamber (12) along a single geometric axis (a) when the culture chamber (12) and flexible pouch (20) ) are received in the outer chamber (24) between a first position in which the mesh bottom (16) of the culture chamber (12) is located at or towards the bottom (28) of the outer chamber (24) and a second position in which the mesh bottom (16) of the culture chamber (12) is spaced from the bottom (28) of the outer chamber (24).trata-se de um biorreator de imersão temporária (10) para produção in vitro de biomassa vegetal diferenciada que compreende uma câmara de cultura (12) que tem uma ou mais paredes laterais transparentes (14) e um fundo de malha (16), sendo que o fun