Wang Shu-Yang, Jiang Bo-Ling, Zhou Xiang, Chen Ji-Hong, Li Wen-Jian, Liu Jing, Hu Wei, Xiao Guo-Qing, Dong Miao-Yin, Wang Yu-Chen
Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd, Lanzhou, Gansu 730000, PR China.
Lanzhou University, 222 South Tianshui Road, Lanzhou, Gansu 730000, PR China.
PLoS One. 2015 Dec 11;10(12):e0144233. doi: 10.1371/journal.pone.0144233. eCollection 2015.
The aim of this study was to evaluate and validate the efficiency of 12C6+ irradiation of Aspergillus niger (A. niger) or mutagenesis via mixed Trichoderma viride (T. viride) culturing as well as a liquid cultivation method for cellulase production via mixed Trichoderma reesei (T. reesei) and A. niger culture fermentation. The first mutagenesis approach was employed to optimize yield from a cellulase-producing strain via heavy-ion mutagenesis and high-throughput screening, and the second was to effectively achieve enzymatic hydrolysis of cellulase from a mixed culture of mutant T. viride and A. niger. We found that 12C6+-ion irradiation induced changes in cellulase biosynthesis in A. niger but had no effect on the time course of the synthesis. It is notable that the exoglucanases (CBH) activities of A. niger strains H11-1 and H differed (6.71 U/mL vs. 6.01 U/mL) and were significantly higher than that of A. niger mutant H3-1. Compared with strain H, the filter paper assay (FPA), endoglucanase (EG) and β-glucosidase (BGL) activities of mutant strain H11-1 were increased by 250.26%, 30.26% and 34.91%, respectively. A mixed culture system was successfully optimized, and the best ratio of T. reesei to A. niger was 5:1 for 96 h with simultaneous inoculation. The BGL activity of the mixed culture increased after 72 h. At 96 h, the FPA and BGL activities of the mixed culture were 689.00 and 797.15 U/mL, respectively, significantly higher than those of monocultures, which were 408.70 and 646.98 U/mL for T. reesei and 447.29 and 658.89 U/mL for A. niger, respectively. The EG activity of the mixed culture was 2342.81 U/mL, a value that was significantly higher than that of monocultures at 2206.57 U/mL for T. reesei and 1727.62 U/mL for A. niger. In summary, cellulose production and hydrolysis yields were significantly enhanced by the proposed combination scheme.
本研究旨在评估和验证12C6+辐照黑曲霉或通过混合绿色木霉培养进行诱变的效率，以及通过混合里氏木霉和黑曲霉培养发酵生产纤维素酶的液体培养方法。第一种诱变方法用于通过重离子诱变和高通量筛选优化纤维素酶生产菌株的产量，第二种方法是有效地实现突变绿色木霉和黑曲霉混合培养物中纤维素酶的酶促水解。我们发现12C6+离子辐照诱导了黑曲霉中纤维素酶生物合成的变化，但对合成的时间进程没有影响。值得注意的是，黑曲霉菌株H11-1和H的外切葡聚糖酶（CBH）活性不同（分别为6.71 U/mL和6.01 U/mL），且显著高于黑曲霉突变体H3-1。与菌株H相比，突变菌株H11-1的滤纸酶活性（FPA）、内切葡聚糖酶（EG）和β-葡萄糖苷酶（BGL）活性分别提高了250.26%、30.26%和34.91%。成功优化了混合培养系统，里氏木霉与黑曲霉的最佳比例为5:1，同时接种培养96小时。混合培养物的BGL活性在72小时后增加。在96小时时，混合培养物的FPA和BGL活性分别为689.00和797.15 U/mL，显著高于单培养物，里氏木霉单培养物的FPA和BGL活性分别为408.70和6
