Abstract: There is disclosed disposal of effluent from a low cell density fermentation process by using such effluent as at least a portion of the feed material to a high cell density fermentation process. A stream containing microbial cells from the high cell density fermentation process is subjected to direct drying.

Abstract: A centrifugal pump adapted for use in a fermentor is provided. The fermentor includes an outer vessel which has mounted therein a generally centrally located draft tube. A centrifugal pump is mounted adjacent to one end of the draft tube and is operably connected to a motor for rotation thereby. The centrifugal pump includes a plurality of vanes radiating outwardly from a region adjacent the center of rotation and cover members positioned on opposite sides of the vanes. The vanes and the cover members cooperate and define flow paths through which medium can be induced to flow due to the centrifugal forces created during rotation of the vanes. The vanes have a distance between respective side boundaries thereof which is less at a position inwardly of the outer disposed end of the vanes than at the outer disposed ends of the vanes.

Abstract: A centrifugal pump adapted for use in a fermenter is provided. The fermenter includes an outer vessel which has mounted therein a generally centrally located draft tube. A centrifugal pump is mounted adjacent to one end of the draft tube and is operably connected to a motor for rotation thereby. The centrifugal pump includes a plurality of vanes radiating outwardly from a region adjacent the center of rotation and cover members positions on opposite sides of the vanes. The vanes and cover members cooperate and define flow paths through which medium can be induced to flow due to the centrifugal forces created during rotation of the vanes. The vanes have a distance between respective side boundaries thereof which is less at a position inwardly of the outer disposed end of the vanes than at the outer disposed ends of the vanes.

Abstract: A fermentation apparatus of the loop flow type includes a tubular member forming a continuous or substantially continuous loop flow path defined by the interior surface of the tubular member. A heat exchanger surrounds a portion of the tubular member and is in heat transfer relation thereto and inside the tubular member at the point where the heat exchange means surrounds the tubular member mixing vanes or fins are secured to the tubular member to effect mixing of medium flowing through the tubular member. A spray nozzle is provided just upstream of the mixing vanes and is operable for discharge of medium into the flow path adjacent the heat exchange means. A pump is connected to the nozzle and pressurizes medium taken from the flow path and discharges same through the nozzle. Injectors open into the flow path adjacent the heat exchange means and are operable for introducing an oxygen-containing gas into the medium contained in the flow path.

Abstract: A fermentation apparatus of the loop flow type includes tubular member forming a continuous or substantially continuous loop flow path defined by the interior surface of the tubular member. A heat exchanger surrounds a portion of the tubular member and is in heat transfer relation thereto and inside the tubular member at the point where the heat exchange means surrounds the tubular member mixing vanes or fins are secured to the tubular member to effect mixing of medium flowing through the tubular member. A spray nozzle is provided just upstream of the mixing vanes and is operable for discharge of medium into the flow path adjacent the heat exchange means. A pump is connected to the nozzle and pressurizes medium taken from the flow path and discharges same through the nozzle. Injectors open into the flow path adjacent the heat exchange means and are operable for introducing an oxygen-containing gas into the medium contained in the flow path.

Abstract: A method for heating microbial cells includes contacting of the cells, which are in a suitable medium forming a dispersion therewith, with heated C.sub.3 -C.sub.8 hydrocarbons at preselected conditions of time, temperature and pressure sufficient for removal of the water. The dewatered cells are then suitably separated from the hydrocarbon heating medium whereby the cells are available for their intended use.

Abstract: An apparatus and method for microbial growth by fermentation with the apparatus including a plurality of vessels connected in series. The fermentation vessels include a prefermenter which feeds microorganism-containing effluent continuously to an intermediate fermenter in which the majority of fermentation is conducted. The intermediate fermenter feeds microorganism-containing effluent to a secondary fermenter in which portions of the feedstock are consumed substantially to extinction. Preferably heat exchangers for each of the vessels are connected in series and an oxygen-containing gas which is partially depleted of oxygen can be fed from the intermediate fermenter to the other fermenters in series.

Abstract: An apparatus for culturing a microorganism by an aerobic fermentation process. The apparatus includes a vessel having a generally centrally located draft tube mounted in a chamber defined by the vessel with the draft tube forming a flow path. The vessel and draft tube are shaped such that the flow path diverges in the direction of ferment flow therethrough. The draft tube has opposite ends with a pump positioned adjacent one end to induce circulation of ferment through the draft tube and along the flow path. A heat exchanger is suitably mounted in the vessel and is in heat transfer relation with the ferment so as to maintain a predetermined operating temperature.

Abstract: An apparatus for the culturing of microorganisms in an aerobic fermentation process. The apparatus includes a vessel with a chamber or reaction zone therein. A draft tube with opposite ends is mounted in the chamber and defines a fluid flow path. A pump means is positioned adjacent one of the draft tube ends and induces flow of fluid through the draft tube and a flow path defined by the draft tube and one interior surface of the vessel. An impeller is positioned between the draft tube and the interior surface of the vessel to assist fluid flow along the flow path defined by same.

Abstract: An apparatus for conducting a fermentation process for the production of single cell protein and the like. The apparatus includes a vessel with a reaction zone and has liquid atomizing means opening thereinto for the injection of atomized liquid into the reaction zone to effect intimate contact of the atomized liquid with a gas phase in the reaction zone. Fermentation medium is supplied to the reaction zone and provides a source of carbon and energy for the culturing of a microorganism and preferably before introduction into the reaction zone said medium is saturated with an oxygen-containing gas.