纤维素降解细菌的筛选、生物学特性及降解效果

Isolation of cellulose-degrading bacteria and determination of their degradation activity

为了从东祁连山高寒草甸土壤中分离筛选纤维素分解细菌,本研究根据在羧甲基纤维素钠培养基和滤纸平板培养基上的生长情况,初步筛选出3株具有较强纤维素分解能力的细菌,并对其生长条件进行了初步研究,结果表明,3株菌的最适生长温度范围为25～30℃;最适生长pH 因菌种不同位于5～8 之间;最适生长盐浓度位于4%～5%.菌株X1-2具有较好降解特性,根据形态观察、革兰氏染色及16SrRNA 系统发育比较,鉴定该菌为芽孢杆菌（犅犪犮犻犾犾狌狊sp.）,是一株十分具有开发生产纤维素酶能力的菌株.

Eight bacterial strains were isolated from soil in the east Qilian Mountains.Of these,four strains had a higher capacity for degradation of plant cellulose when cultured on a CMC-Na plate medium.The growth characteristics of the four strains were studied,and the optimum temperature range of the 4active strains was25-30℃,the optimum pH for growth was 5-8,and the optimum sodium concentration was 4% to 5%.A strain designated X1-2possessed the highest cellulose degradation ability.Based on morphology,gram stain reaction,and 16 SrRNA phylogenetic comparison,this strain was identified as a member of the genus Bacillus(Bacillus sp.).It is a bacterium with strong plant cellulose degradation ability.