Bacteria from an activated sludge treatment plant handling waste-water from a factory producing high-quality cardboard were isolated using a non-selective defined medium. A wide range of organims was growth in a defined medium. This was not produced by enteric bacteria but was observed with som preudomonas and acinetobacters, a rose-coloured Gram negative organism and some filamentous Gram negative bacteria. Flocculation appeared to be substrate dependent and a few organismns produced flocculant growth even in rich complex media