Department of Bioengineering, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, 940-2188, Japan.
J Ind Microbiol Biotechnol. 2019 Jun;46(6):831-842. doi: 10.1007/s10295-019-02155-9. Epub 2019 Feb 26.
Filamentous fungi produce a variety of proteases with significant biotechnological potential and show diverse substrate specificities. Proteolytic analysis of the industrial enzyme producer Trichoderma reesei has been sparse. Therefore, we determined the substrate specificity of T. reesei secretome and its main protease Trichodermapepsin (TrAsP) up to P1 position using FRETS-25Xaa-libraries. The role of TrAsP was analyzed using T. reesei QM9414 and the deletant QM∆trasp in Avicel. We observed higher activities of CMCase, Avicelase, and Xylanase in QM∆trasp compared to that of QM9414. Saccharification rate of cellulosic biomass also increased when using secretome of QM∆trasp but the effect was not significant due to the absence of difference in BGL activity compared to QM9414. Higher TrAsP was produced when monosaccharides were used as a carbon source compared to cellulase inducers such as Avicel and α-sophorose. These results elucidate the relationship between TrAsP and cellulase production in T. reesei and suggest a physiological role for TrAsP.
丝状真菌产生多种具有重要生物技术潜力的蛋白酶，表现出不同的底物特异性。工业用酶生产菌里氏木霉的蛋白水解分析一直很少。因此，我们使用 FRETS-25Xaa-文库确定了里氏木霉分泌液及其主要蛋白酶里氏木霉胃蛋白酶（TrAsP）在 P1 位的底物特异性。使用里氏木霉 QM9414 和缺失突变体 QM∆trasp 在微晶纤维素上分析了 TrAsP 的作用。与 QM9414 相比，QM∆trasp 表现出更高的 CMCase、Avicelase 和木聚糖酶活性。当使用 QM∆trasp 的分泌液时，纤维素生物质的糖化率也增加了，但由于与 QM9414 相比 BGL 活性没有差异，因此效果并不显著。与微晶纤维素和 α-槐糖等纤维素诱导剂相比，当使用单糖作为碳源时，产生的 TrAsP 更高。这些结果阐明了 TrAsP 与里氏木霉中纤维素酶生产之间的关系，并暗示了 TrAsP 的生理作用。
