To secrete the endo-beta-1,4-mannanase of Bacillus subtilis WL7 in Escherichia coli, the ABC exporter (TIiDEF) and the C-terminal signal sequences of lipase (TliA) and metalloprotease (PrtA) were used. Six C-terminal fragments of TliA (TliAC1, TIiAC2 and T1iAC3) and PrtA (PrtAC1, PrtAC2 and PrtAC3) were amplified by PCR, respectively, and were fused to the mature mannanase gene lacking its original N-terminal signal sequence. When coexpressed with TIiDEF exporter gene in E. coli, all the fusion mannanases were successfully secreted to the culture supernatant as an enzymatically active form by TIiDEF exporter in E. coli. However, the unspecific cell leakage occurred in the fusion mannanases containing TliA-derived signal sequences. Among the fusion mannanases containing the signal sequences of PrtA, the mannanase with the shortest signal sequence fragment (Man-PrtAC3) exhibited the highest secretion level (4.65 mg/L). Moreover, the specific activity, the effect of temperature and pH on activity and stability were almost identical to the wild-type mannanase, indicating that the fused signal sequence of PrtA did not affect the enzymatic properties of mannanase. It was concluded that the efficient secretion of enzymatically active mannanase from Bacillus subtilis WL-7 was achieved by using PrtAC3 as the most adequate signal sequence fragment. (C) 2016 Published by Elsevier Ltd.