Residual acrylonitrile monomer was quantitatively removed from aqueous
polymer emulsions (latexes) of nitrilic rubbers by means of whole cel
ls and cellular lysates of Brevibacterium imperiale and Corynebacteriu
m nitrilophilus. A commercially-available immobilized nitrilase prepar
ation allowed the conversion of acrylonitrile into acrylic acid and th
e recycle of the catalyst with retention of the reaction efficiency.