一株木霉菌(Trichoderma sp.)TY2纤维素酶最佳产酶条件及部分酶学特性研究

Optimal Production Enzyme Condition of One Strain Aspergillus Trichoderma Sp. Ty2 and Enzymological Characters

【目的】筛选高活力纤维素酶产生菌,高效利用纤维素资源。【方法】从朽木和和纸浆样品中分离筛选出一株产纤维素酶活较高的菌株TY2。对其形态和18SrDNA特征序列分析鉴定为木霉菌(Trichodermasp.)。对菌株发酵条件及酶学特性进行研究。【结果】TY2菌株的最佳产酶条件为:1%滤纸+2%麸皮+0.5%葡萄糖为碳源,0.5%蛋白胨为氮源,起始pH5.0,温度28℃,200r/min,5d,其CMCase和FPase活力分别达412.5和100.3U/mL。经分离纯化出TY2菌株内切β-葡聚糖苷酶。内切β-葡聚糖苷酶最适反应温度为60℃,最适反应pH为4.6,在50℃以下,pH3.0～5.0,酶活性稳定,且在80℃仍具有降解CMC-Na的效果。同时研究发现铜离子、锌离子、钾离子和钠离子对内切β-葡聚糖苷酶的酶活有促进作用,而汞离子有明显的抑制作用。【结论】所筛选的TY2菌株具有潜在的工业应用价值。

[Objective and Method]The present research was designed to screen cellulase production strain with high activity,to highly use cellulase resources,the strain of fungi named TY2 could decompose cellulose efficiently.It was identified as Trichoderma sp.by morphology identification and 18S rDNA sequence analysis.[Result]The results showed that the optimum cellulase production conditions for TY2 producing cellulase were 1% filter paper,2% wheat bran and 0.5% glucose as carbon sources,0.5% peptone as nitrogen source,40 mL liquid medium in 150 mL flask,inoculation amount 6%,the initial pH 5.0,fermentable temperature 28 ℃,200 r/min of rotation,fermentation time 5 days,the enzyme activity of CMCase and the FPase reached 412.5 U/mL and 100.3 U/mL respectively conditions.A endo-β-glucanase from TY2 strain was separated and purified.The optimal temperature and pH for endo-β-glucanase activity were about 60 ℃ and 4.6,the enzyme activity was stable during the pH 3.0～5.0 and under 50 ℃.It still has the ability of degradation CMC-Na at 80 ℃,Cu2＋,Zn2＋,K＋ and Na＋ can activate the activity of endo-β-glucanase,while Hg ＋ inhibited the enzymatic activity.[Conclusion]The strain TY2 has certain applied value in industry.