Two strains which produced β-mannanase were isolated from soil by enriching and isolating. A strain with the higher enzyme activity of 50.37 U/ml was obtained after the enzyme activity assay. The strain was identified as Pseudomonas sp. by morphological and physiological characteristics analysis and 16S rDNA BLAST. The optimal conditions for producing β-mannanase by the strain were determined 1 g/l00 ml maizena, 2 g/100 ml konjak powder, pH6.0 and the optimal temperature was 32 ℃, under which the activity of β-mannanase was up to 185.37 U/ml,3.68 times as before. The strain which rapidly produced β-mannanase showed the highest β-mannanase activity after culturing for 12 h. The study of the enzymatic character of the β-mannanase revealed that it was the acidic β-mannanase, and the optimal condition of the enzyme was pH4.0 and 60℃, respectively. The activity of β-mannanase was stable at pH4.0～6.0 and 40～55℃.%以采集的土壤样品为试验材料,经过富集培养及分离纯化,筛选出2株产β-甘露聚糖酶的菌株.采用摇瓶培养分别测定其酶活力,其中1株菌株酶活力较高,酶活力达50.36 U/ml.生理生化性质鉴定及16S rDNA序列相似性结果表明该菌为假单孢菌(Pseudomonas sp.).产酶的最适条件研究发现,1 g/100 ml玉米粉,2 g/100 ml魔芋粉,pH6.0,32℃为最优产酶条件,酶活力达185.37 U/ml,是优化前的3.68倍.该菌产酶迅速,培养12 h后已达产酶高峰.粗酶的性质研究发现,该酶是一种酸性的甘露聚糖酶,作用的最适pH为4.0,最适反应温度为55℃;该酶的稳定性较好,在pH4.0～6.0、温度为40～55℃保持较好的稳定性.
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