A truncated alkaline β-mannanase from alkaliphilic Bacillus sp. N16-5 (MAN330) was expressed and secreted in Kluyveromyces cicerisporus. The recombinant engineered strain for MAN330 production was stable during 80 generations, and the maximum yield of MAN330 reached 3,795 U/ml in 15 l fermenter. MAN330 exhibited similar pH optima, temperature optima, and substrate specificities to its full-length protein (MAN493). However, stability of MAN330 was about 7% higher than that of MAN493 from pH 9-11. MAN330 had about 10% higher stability than MAN493 from 60°C to 80°C.