A bioreactor cleaning system for cleaning a bioreactor , preferably a bioreactor in a rail vehicle, with a suction unit for suctioning liquid from the bioreactor , the suction unit having a suction connection for connecting to the bioreactor ; a supply unit for supplying liquid into the bioreactor , the supply unit having at least one supply connection for connecting to the bioreactor ; an electronic control unit for controlling the suction unit and the supply unit; an acid tank for receiving an aqueous acid solution; a collection tank for receiving liquid suctioned from the bioreactor; and a fresh water connection for supplying the bioreactor cleaning system with fresh water; wherein the supply unit is connected to the fresh water port and the acid tank to selectively provide fresh water and/or aqueous acid solution to the supply connection , and wherein the suction unit for suctioning liquid from the bioreactor is selectively connectable to the acid tank or the collection tank for supplying acid solution suctioned from the bioreactor to the acid tank and for supplying substantially pH-neutral residual fluid suctioned from the bioreactor to the collection tank ; and with a dosing unit , which has one or more acid canister ports for connecting acid canisters and one or more base canister ports for connecting base canisters , an acid doser connectable on the input side to the one or more acid canister ports and on the output side to the acid tank , and a base doser connectable on the input side to the one or more base canister ports and on the output side to the acid tank , and a mixer, wherein the mixer can be connected on the input side to a fresh water connection and the acid dosing unit and/or base dosing unit , and on the output side to the acid tank in order to supply the acid tank with a solution usable to neutralize the acid solution present in the acid tank . a suction unit for suctioning liquid from the bioreactor , the suction unit having a suction connection for connecting to the bioreactor ; a supply unit for supplying liquid into the bioreactor , the supply unit having at least one supply connection for connecting to the bioreactor ; an electronic control unit for controlling the suction unit and the supply unit; an acid tank for receiving an aqueous acid solution; a collection tank for receiving liquid suctioned from the bioreactor; and a fresh water connection for supplying the bioreactor cleaning system with fresh water; wherein the supply unit is connected to the fresh water port and the acid tank to selectively provide fresh water and/or aqueous acid solution to the supply connection , and wherein the suction unit for suctioning liquid from the bioreactor is selectively connectable to the acid tank or the collection tank for supplying acid solution suctioned from the bioreactor to the acid tank and for supplying substantially pH-neutral residual fluid suctioned from the bioreactor to the collection tank ; and with a dosing unit , which has one or more acid canister ports for connecting acid canisters and one or more base canister ports for connecting base canisters , an acid doser connectable on the input side to the one or more acid canister ports and on the output side to the acid tank , and a base doser connectable on the input side to the one or more base canister ports and on the output side to the acid tank , and a mixer, wherein the mixer can be connected on the input side to a fresh water connection and the acid dosing unit and/or base dosing unit , and on the output side to the acid tank in order to supply the acid tank with a solution usable to neutralize the acid solution present in the acid tank . <EOS>