Abstract Enzymes (β- d -xylosidase, endoxylanase and endocellulase), isolated from Thermobifida fusca moderate thermophile organism, have been stabilized as single enzyme nanoparticles. During the stabilization process every individual enzyme molecule is covered with a thin polyacrylamide polymer layer. This polymer layer has a cross-linked spatial structure but thin and porous enough to allow the diffusion of substrate molecules to the active centrum of the enzyme molecule and the enzymatic function of the pretreated enzyme. A new, easily realizable two-step process was used to prepare enzyme nanoparticles. The catalytic activity of these three native enzymes and enzyme nanoparticles prepared were measured as a function of the incubation time, with 150 rpm shaking at 50 °C as optimal temperature. All enzymes are significantly more stable in form of enzyme nanoparticles than in their natural state. Heat stability of β- d -xylosidase enzyme was also investigated at 80 °C and 150 rpm. The half-life time of activity of enzyme nanoparticles obtained was about two-order of magnitude longer than that of the natural ones.