A β-mannanase-producing lactic acid bacteria (LAB) was identified as Weissella cibaria F1 according to physiological and biochemical properties, morphological observations, partial sequence of 16S rRNA gene and API 50 CHL test. In order to improve the yield of β-mannanase, the response surface methodology (RSM) was originally used to optimize the fermentation conditions. The optimization results showed that when the konjac powder, glucose, and initial pH were 9.46 g/L, 14.47 g/L and 5.67, respectively, the β-mannanase...