GB615891A - Process for the recovery of valuable constituents from yeast, etc. - Google Patents

Abstract

Purine-nucleotides, other than those having a substituted 7-position in the purine group, are extracted from a nucleoprotein containing the same by heating such substance in the presence of an aqueous solution of caustic alkali until the nucleic acid is freed from its protein combination and hydrolysed into its nucleotide constituents which pass into solution, together with the gum and protein constituents of the substance and thereupon successively precipitating and removing the latter constituents from the resulting slurry and finally precipitating the purine nucleotides. The gum and protein constituents may be precipitated in either order. Preferably, the slurry obtained by treatment of the nucleo-protein, say, yeast with alkali is treated with a mineral acid such as sulphuric acid to adjust its pH to substantially the isoelectric point of the proteins, whereupon the solution is boiled, cooled and the coagulated proteins removed together with insoluble yeast components such as cell walls; the solution is then treated with alkali until the isoelectric point for the precipitation of the gums is reached and the gums removed. Alternatively, the gums are first precipitated from the initial strongly alkaline slurry by addition of copper sulphate and removed, and the solution then treated as above to remove the protein constituents. The gum and protein-free solution containing the purine nucleotides is then treated for their precipitation; the method described in Specification 590,995 may be followed for precipitating them in the form of the cuprous salts which may be further treated as therein described. According to examples, yeast is hydrolysed with 2-3 per cent caustic soda at 60 DEG to 65 DEG C. for an hour, the gum and protein constituents successively precipitated and removed by either of the above methods and the resulting clear solution is adjusted to a pH value of between 5.5 and 8.5, heated to boiling and copper sulphate and sodium bisulphite added, preferably, to give a final pH of between 2.9 and 3.1 and the precipitated cuprous purine nucleotides are then filtered off and washed. In addition to yeast, moulds, bacteria, blood cells and other nucleic acid bearing substances may be similarly treated.ALSO:A high protein feed adjunct is obtained by heating a nucleo protein, especially yeast, in the presence of an aqueous solution of a caustic alkali until the nucleic acid is freed from its protein combination and hydrolysed into its nucleotide constituents which pass into solution together with the gum and protein constituents of the nucleoprotein and then precipitating the proteins, suitably, by adjusting the pH of the hydrolysis mixture to the isoelectric point for the proteins. Insoluble yeast constituents such as cell walls present in the hydrolysis mixture may be removed before the precipitation or together with the precipitated proteins.