Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China.
J Biosci Bioeng. 2011 Feb;111(2):121-7. doi: 10.1016/j.jbiosc.2010.09.004. Epub 2010 Nov 10.
A new Trichoderma viride stain was isolated from Singapore soil samples. Its mutants were developed by using ethyl methyl sulfonate (EMS) treatment and UV-irradiation followed by a semi-quantitative plate clearing assay on phosphoric-acid-swollen cellulose plates. Mutant EU2-77 proved to be the most promising extracellular cellulase producer among 20 mutants in a screening program performed in shake flask fermentation after plate screening. Soluble protein content, filter paper cellulase (FPase) activity, β-glucosidase activity and endoglucanase (CMCase) activity of the fermentation broths of the mutant strain were increased to 1.67, 2.49, 2.16, and 2.61 folds, respectively, compared with the wild strain. This enzyme complex produced by mutant EU2-77 contained FPase (2.19 IU/ml), CMCase (16.46 IU/ml), β-glucosidase (4.04 IU/ml), xylanase (42.37 IU/ml), and β-xylosidase (0.12 IU/ml). The soluble protein concentration in the enzyme complex was 1.69 mg/ml. The hydrolytic capacities of fermentation supernatants of T. reesei Rut-C30, the wild strain T. viride NP13a and mutant T. viride EU2-77 were compared with the commercial enzymes on the hydrolysis of waste newspaper. The crude enzymes prepared by T. viride EU2-77 showed much higher hydrolysis performance than that from the commercial strain Rut-C30 and demonstrated much comparable hydrolytic performances with the commercial enzyme mixtures. T. viride mutant EU2-77 produced high levels of extracellular cellulases as well as β-glucosidase, rendering the supplementation of β-glucosidase unnecessary in waste newspaper hydrolysis.
从新加坡土壤样本中分离到一株新的绿色木霉菌株。采用乙基磺酸甲酯（EMS）处理和紫外线照射的方法对其进行诱变，然后在磷酸膨胀纤维素平板上进行半定量平板透明圈试验，筛选出突变株。在平板筛选后进行的摇瓶发酵筛选计划中，EU2-77 突变株是 20 株突变株中最有前途的胞外纤维素酶产生菌。与野生菌株相比，突变株 EU2-77 的发酵液中可溶性蛋白含量、滤纸纤维素酶（FPase）活性、β-葡萄糖苷酶活性和内切葡聚糖酶（CMCase）活性分别提高了 1.67、2.49、2.16 和 2.61 倍。EU2-77 突变株产生的这种酶复合物包含 FPase（2.19 IU/ml）、CMCase（16.46 IU/ml）、β-葡萄糖苷酶（4.04 IU/ml）、木聚糖酶（42.37 IU/ml）和β-木糖苷酶（0.12 IU/ml）。酶复合物中的可溶性蛋白浓度为 1.69 mg/ml。比较了里氏木霉 Rut-C30、野生绿色木霉 NP13a 和突变绿色木霉 EU2-77 的发酵上清液的水解能力与商业酶在废纸水解中的应用。与 Rut-C30 商业菌株相比，EU2-77 突变株制备的粗酶显示出更高的水解性能，与商业酶混合物的水解性能相当。EU2-77 突变株绿色木霉产生高水平的胞外纤维素酶和β-葡萄糖苷酶，因此在废纸水解中不需要添加β-葡萄糖苷酶。
