(DE4309129-C1)      In recovering a conc. protein extract from liq. manure by mixing with a fast-growing yeast with high C content, high O content and N and H, with addn. of trace elements according to analysis of the manure, the yeast is mixed with liq. manure largely freed from solids by centrifuging, and the manure is circulated at 37 deg.C and under slight excess pressure, with periods of acceleration and periods of rest, until a protein assimilate has been formed; the remaining liq. is finally drawn off.    Pref. circulation is in small side streams, between larger amts. at rest.    USE/ADVANTAGE -   The conc. protein extract can be utilised. The process is cheap.    (DE4337754-C1)      The appts. to recover a conc. protein extract from manure, through the addn. of a rapid growth yeast and other additives at a low pressure and raised temp. has pipe connections (4,5) linking the interiors of two longitudinal and adjacent containers (1,2), at least at a part zone, from one end of the lower container to an end of the upper container.    At least one container (2) has a feed connection (7) at the end for the manure, at at least one container (1) has an outlet connection (8) at the other end for the fermentation. At least one container (1) has heating (9). Both containers (1,2) have an air feed (10) and pressure for their interiors.    ADVANTAGE -   The appts. gives an effective action for the recovery of conc. protein extract.    (EP616759-B1)      Process for obtaining a concentrated protein extract from liquid manure by adding a rapidly growing yeast with a high carbon content, a high oxygen fraction as well as nitrogen, hydrogen and trace elements which are metered according to an analysis of the liquid manure, characterised in that the yeast is added to the liquid manure, which is largely liberated by centrifuging solid matter, the liquid manure is circulated in a ciruit with acceleration sections and moderating intervals at a temperature of approximately 37 deg.C and under the effect of a pressure slightly above atmospheric until a protein assimilate is formed, and the remaining liquid is subsequently drawn off.