Studies on the Utilization of Single Cell Proteins

Part II. On the partial acid hydrolysis of the sludge of high ash content to be applied for the extraction of amino acids

Abstract

For higher utilities of the proteins obtained from the dried and activated sludge of high ash contents, the conditions economically and technologically favorable for the partial hydrolysis by acid were investigated. The hydrolysates of the dried sludge obtained under the conditions differing in the concentrations and the volumes of the acids, and in the time intervals for the hydrolysis were subjected to the determination of the soluble- and ammoniacal-nitrogen, trinitrobenzen sulfonate positive substances and 18 kinds of amino acid.
Among the conditions thus investigated, the followings were concluded to present the adequate results for the amino acid recoveries: 1.05kg/cmcm² of the autoclaving pressure, 4 hours for heating, 4-6N of hydrochloric acid (over 270mg per g of dried sludge) or sulfuric acid (over 290mg per g of dried sludge).