β-甘露聚糖酶产生菌的分离鉴定和酶学性质

Isolation,identification and enzymatic characterization of β-mannanase producing strain

从工厂废液中分离并筛选到了1株产β-甘露聚糖酶的菌株CYS4,其摇瓶培养液的酶活力为11.0U/mL。经形态观察、生理生化试验及16S rDNA序列分析鉴定为枯草芽孢杆菌（Bacillus subtilis）。酶学性质研究结果表明：该酶的最适反应pH值为7.0,在pH值为5.0-11.0时能保持很好的稳定性,酶活力在80%以上;该酶的最适反应温度为60℃,在温度低于40℃时基本稳定,保温3 h酶活力仍然有70%以上;Na^＋、Fe^2＋、Mn^2＋、Zn^2＋、Mg^2＋等金属离子对该酶有激活作用,Hg2＋对酶活有一定的抑制作用。

A β-mannanase producing strain CYS4 was isolated from factory waste liquid and its enzyme activity reached 11.0 U/mL in the culture liquid of shaking flask.CYS4 was identified as Bacillus subtilis based on morphological observation,physiological and biochemical experiments and phylogenetic analysis with 16S rDNA sequence.Enzymatic characterization showed that the optimum pH for the enzyme was 7.0,it was stable between pH 5.0 and pH 11.0,the enzyme activity is more than 80%,and the optimum temperature was 60 ℃,it was stable under 40 ℃,the enzyme was still more than 70% after 3 hours.The enzyme activity was activated by Na^＋,Fe^2＋,Mn^2＋,Zn^2＋,Mg^2＋,but inhibited by Hg^2＋.