Feruloyl esterases are of great interest due to their enhancement of the accessibility of xylanase to the backbone of xylan by debranching the side chain decoration of hemicellulose. Alternaria alternata is known for its ability to secrete abundant xylanolytic enzymes, but the pathogenicity greatly limits the production of feruloyl esterase. Herein, we first cloned the thermostable alkaline faeB gene of A. alternata and successfully expressed in Pichia pastoris GS115. The recombinant AaFAEB was purified to homogeneity and the specific activity of purified AaFAEB was 18.39 ± 0.26 U/mg. The optimal temperature and pH for AaFAEB was about 45 °C and 7.0. The recombinant AaFAEB showed excellent thermal stability at 45–60 °C and can retain 71.31% of the maximum activity after incubation for 1 h at 60 °C. In addition, it exhibits broad pH stability and can retain approximately 68% of its maximum activity at pH 10.0 for 2 h. The substrate specificity profiling and phylogenetic analysis confirmed that AaFAEB is a type B FAE. Pretreatment by AaFAEB can synergistically promote the enhancement of the Fock reactivity of dissolving pulp by endoglucanase. In addition, it can increase the α-cellulose content by the cooperation with xylanase, thereby further improving the quality of dissolving pulp. The present results suggested that the recombinant AaFAEB is a promising candidate for dissolving pulp production and biorefining industry.

阿魏酸酯酶引起了极大的兴趣，因为它们通过使半纤维素的侧链装饰脱支来增强木聚糖酶对木聚糖骨架的可及性。链格孢以分泌大量木聚糖分解酶的能力而闻名，但其致病性极大地限制了阿魏酸酯酶的产生。在此，我们首先克隆了A. alternata的耐热碱性fae B 基因，并在毕赤酵母中成功表达。GS115。将重组AaFAEB纯化至均质，纯化的AaFAEB比活性为18.39±0.26 U/mg。AaFAEB 的最佳温度和 pH 值约为 45 °C 和 7.0。重组AaFAEB在45-60°C下表现出优异的热稳定性，在60°C下孵育1小时后可保留71.31%的最大活性。此外，它表现出广泛的 pH 稳定性，在 pH 10.0 下 2 小时可保持其最大活性的约 68%。底物特异性分析和系统发育分析证实 AaFAEB 是 B 型 FAE。AaFAEB预处理可以协同促进内切葡聚糖酶对溶解浆的Fock反应性的增强。此外，通过与木聚糖酶的协同作用，可以提高α-纤维素的含量，从而进一步提高溶解浆的质量。