中文摘要：

为了筛选高产卢一甘露聚糖酶的细菌菌株，利用刚果红染色法从土壤中筛选分离到l株产β一甘露聚糖酶菌株MM5。通过形态观察、生理生化试验及16SrDNA序列分析进行鉴定，确定其为枯草芽孢杆菌（Bacillus subtilis）。菌株MM5产甘露聚糖酶的活力达到1594U／mL，以MM5为出发菌株，通过紫外诱变得到诱变菌株LD24H4，酶活提高到3717U／mL。通过单因素试验和正交试验确定了菌株LD24H4产酶的最佳培养基组分（g／L）：魔芋粉20．0，干酪素2．5，NaCl1．0，MgSO40．5，KH2PO40．5，pH7．5。最适产酶培养条件：47℃，装液量90mL（250mL三角瓶），接种量1％，转速200r／min，在此条件下发酵26h，甘露聚糖酶活力高达12534U／mL，是优化前的3．37倍。

英文摘要：

The congo red staining method was used to screen β-mannanase producing strains with high yield. A strain MM5 was isolated from soil. The stain MM5 was identified as Bacillus subtilis according to the results of physiological and biochemical tests as well as 16S rDNA sequence analysis. The activity of β- mannanase by strain MM5 achieved 1 594 U/mL. After the strain MM5 was treated with ultraviolet radiation, a mutant strain LD24H4 was obtained and its activity increased to 3 717 U/mL. Our experiment adopted the single-factor design and orthogonal design. According to their results, the optimal culture medium （ per liter） of LD24H4 for β-mannanase production was determined as 20.0 g konjac powder, 2.5 g casein, 1.0 g NaC1, 0.5 g MgSO4, 0.5 g KH2PO4, pH 7.5. The optimal conditions for fermentation were obtained as the temperature of 47 ℃ , inoculation volume of 1% , 90 mL of culture medium in a 250 mL flask, and rotation speed of 200 r/rain. Under the optimal conditions for 26 hrs, the β-mannanase activity increased to 12 534 U/mL, 3.37 times as high as the original activity.