Acetyl xylan esterases are among the key enzymes in the xylan degradation enzyme system. However, acetyl xylan esterases from natural microorganisms have low expression and low enzyme activity and are impure. In this study, a new xylanase gene, est1051, from the metagenomic library, was expressed in the prokaryotic system. Its enzymatic properties were explored, including optimum temperature and pH, thermal and pH stability, and tolerance against organic solvents, metal ions and salt solutions. Then the fermentation conditions of EST1051 were optimized by the response surface method, and the maximum enzyme yield reached 1909.32 U/L. Finally, the synergism with cellulase on straw degradation was evaluated. EST1051 displays high homology with acetylxylan esterases in terms of amino acid sequences and conserved active sites. EST1051 shows high stability across a broad temperature range, and retains more than 60% of its enzymatic activity between 4 and 60°C after 24 h of incubation. Single-factor analysis and orthogonal design were conducted to determine the optimal conditions for the maximizing the saccharification rate of wheat straws. Interestingly, the synergism of EST1051 with cellulase contributes to the efficient transformation of wheat straws. These findings may open the door to significant industrial applications of this novel acetylxylan esterase.

乙酰木聚糖酯酶是木聚糖降解酶系统中的关键酶。然而，来自天然微生物的乙酰木聚糖酯酶表达量低，酶活性低，不纯。在这项研究中，一个新的木聚糖酶基因est1051，来自宏基因组文库，在原核系统中表达。研究了其酶学特性，包括最适温度和 pH 值、热稳定性和 pH 值稳定性以及对有机溶剂、金属离子和盐溶液的耐受性。然后采用响应面法对EST1051的发酵条件进行优化，最高产酶量达到1909.32 U/L。最后，评估了与纤维素酶对秸秆降解的协同作用。EST1051 在氨基酸序列和保守的活性位点方面与乙酰木聚糖酯酶具有高度同源性。EST1051 在很宽的温度范围内显示出高稳定性，并且在 4 到 60°C 之间孵育 24 小时后，其酶活性保持在 60% 以上。通过单因素分析和正交设计，确定了使麦秆糖化率最大化的最佳条件。有趣的是，EST1051 与纤维素酶的协同作用有助于小麦秸秆的高效转化。这些发现可能为这种新型乙酰木聚糖酯酶的重要工业应用打开大门。