A protease-resistant exo-polygalacturonase from Klebsiella sp. Y1 with good activity and stability over a wide pH range in the digestive tract

► An exo-polygalacturonase of PF00295, exo-PGU B, was identified in Klebsiella sp.Y1. ► Recombinant exo-PGU B has good adaptability to pH and stability over a wide pH range. ► Exo-PGU B alone or in combination reduces the viscosity of polygalacturonic acid solution. ► Exo-PGU B has protease resistance and is active and stable in the digestive tract.