【目的】筛选高效分泌纤维素酶的细菌,为纤维素资源利用提供理论依据。【方法】以羧甲基纤维素钠(CMC-Na)为唯一碳源,对通过筛选培养基从森林湿泥样品中分离筛选出的细菌,采用刚果红染色、革兰氏染色和生化特性及16SrDNA进行鉴定,并对菌株产酶性质进行初步研究。【结果】获得一株纤维素酶产生菌L-30,该菌株在pH4.8、50℃条件下的酶活力为4.25 U/mL,经鉴定L-30为蜡样芽孢杆菌。酶学性质研究表明,L-30菌株所产纤维素酶最适反应pH为6.0,最适温度为50℃,该条件下酶活力最高,达4.95 U/mL,该酶对CMC-Na具有较强的分解能力;L-30菌株在最佳生长条件下,于接种后48 h即可达到产酶高峰,L-30菌株的产纤维素酶能力能稳定遗传。【结论】分离到的L-30为一株高产纤维素酶蜡样芽孢杆菌,其酶学性质好,具有进一步开发利用的价值。[Objective]Cellulase, efficiently producing bacteria, was screened to provide references for cellulose application.[Method]Bacteria was screened by using CMC-Na as the only carbon source from humid soil sample. The methods of Congo red staining, gram staining, biochemical character and molecular property of 16S rDNA were used to identify the bacteria, and the enzymatic properties of the cellulose were also observed. [Result]One strain of cellulase producing bacteria （L-30） was isolated from the humid soil sample. The cellulase activity was 4.25 U/mL in the conditions of pH 4.8 and 50℃. L-30 was identified as Bacillus cereus. The preliminary study on enzymatic properties showed that under the optimum conditions of pH of 6.0 and temperature of 50℃, the cellulose activity reached 4.95 U/mL in this reaction system. The cellulase showed high ability to degrade CMC-Na. L-30 reached its largest amount of the enzyme after cultured for 48 hours and displayed genetic stability on secreting enzyme. [Conclusion]The isolated Bacillus cereus of L-30 with good enzymatic properties should be further developed and utilized.广西林产化学与工程协同创新高水平研究项目(2013B01)； 广西自然科学基金项目(2012GXNSFAA053060)； 广西高校科学技术研究项目(2013YB069
