Abstract: An aqueous cleaning and disinfecting concentrate comprisingA) at lease one reaction product ofa) an N-substituted propylene diamine of formula IR.sup.1 --NH--(CH.sub.2).sub.3 --NH.sub.2 (I)in which R.sup.1 is a C.sub.8 -C.sub.18 alkyl group andb) glutamic acid or a glutamic acid derivative of formula IIR.sub.2 --O--CO--(CH.sub.2).sub.2 --CH(NH.sub.2)--COOH (II)in which R.sup.2 is hydrogen or a C.sub.1 -C.sub.4 alkyl group, wherein the said reaction product is optionally ethoxylated and/or propoxylated, and is optionally in the form of a salt with an organic or inorganic acid;B) at least one of the following antimicrobially active compounds:i) a quaternary ammonium compound of formula III ##STR1## in which R.sup.3 and R.sup.4 independently of one another represent alkyl radicals containing 1 to 3 carbon atoms or benzyl radicals, or halogenated or alkylated benzyl radicals containing 6 to 22 carbon atoms, and X.sup.