Cloning and characterization of a modular GH5 β-1,4-mannanase with high specific activity from the fibrolytic bacterium Cellulosimicrobium sp. strain HY-13

► The novel, modular GH5 β-1,4-mannanase gene of Cellulosimicrobium sp. strain HY-13 was cloned. ► Recombinant ManH displayed high specific activity toward mannan polysaccharides. ► The enzyme was bound to ivory nut mannan, Avicel, chitosan, and chitin. ► ManH has a great potential as an animal feed additive.