一株产耐热甘露聚糖酶细菌的筛选及其酶学性质初探

Screening of a Thermophilic Mannanase Producing Bacterium and Studies on the Enzymatic Properties of Mannanase

为获得耐热甘露聚糖酶,从天然高温泉水中筛选出了一株产甘露聚糖酶的细菌。结合形态学、生理生化和分子生物学等手段,确定所筛选的菌株为地衣芽孢杆菌(Bacillus licheniformis)。并研究了温度、pH值和金属离子等因素对甘露聚糖酶活力的影响。结果显示,该酶的最适反应温度和pH分别为60℃和5.0。Co^(2+)和Al^(3+)对该酶的活力有抑制作用,Mn^(2+)、K^+和Ca^(2+)对该酶活力有一定的促进作用,其它离子对酶活力没有显著影响。该菌株生产的甘露聚糖酶具有耐热偏酸性的特点。该研究为甘露聚糖酶制剂产业提供了可靠的菌种资源,可用于纺织、食品、饲料等方面,并为将来进一步研究其用途奠定了基础。

A mannanase producing bacterial strain named Mas1 was newly isolated from a hot spring in Jiangxi Province.Mas1 was identified as B.licheniformis by 16 SrRNA gene sequence analysis,morphological detection,physiological and biochemical identification.The effect of temperature,p H and metal ions on the activity and stability of crude mannanases from B.licheniformis Mas1 was studied.The results showed that the optimal temperature and p H for the mannanase activity was 60 ℃ and 5.0 respectively; Co^（2＋） and Al^（3＋） were the most effective inhibitor of the enzyme activity,while Mn^（2＋）,K~＋ and Ca^（2＋） could promote the activity of the enzyme,and other ions had no significant effect on the enzyme activity.This strain could be used for the production of mannan-degrading enzymes,and has great potential for applications in textile,food,feed and other fields.