GB345368A - Improved manufacture of organic acids - Google Patents

Abstract

Organic acids such as citric, oxalic, malic, succinic, and fumaric acids are produced by inoculating sections or slices of plants containing fructose or fructose-yielding carbohydrates, such as for example sucrose or inulin, with a selected acid-producing fungus strain and growing the fungus thereon. The cellular tissue of the plant sections may be broken down by successive freezing and thawing, and an alkaline or buffer material, preferably insoluble, may be applied to the sections, e.g. calcium carbonate, barium carbonate, zinc oxide or calcium phosphate. The sections may also be intermixed with inert packing material before inoculation. Slices of sugar beets or Jerusalem artichoke tubers or sections of sugar cane or sorghum cane may be used in layers between which open grids of wood, Raschig rings or other resistant material is placed, or coils used for controlling the temperature may also act as supports for the material. Closed tanks are used so that the supply of oxygen or air may be controlled. The process may be made continuous by the use of rotating inclined drums. The fungi employed are ordinarily of the genera aspergillus, e.g. aspergillus niger, penicillium, citromycetes, mucor, &c. Various strains of rhizopus may be employed in the production of fumaric and succinic acids.