Two degradation strategies for overcoming the recalcitrance of natural lignocellulosic xylan by polysaccharides-binding GH10 and GH11 xylanases of filamentous fungi
Two degradation strategies for overcoming the recalcitrance of natural lignocellulosic xylan by polysaccharides-binding GH10 and GH11 xylanases of filamentous fungi
复制标题
丝状真菌多糖结合 GH10 和 GH11 木聚糖酶克服天然木质纤维素木聚糖顽抗性的两种降解策略。
DOI：
10.1111/1462-2920.13614
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发表时间：
2017-03-01
影响因子：
5.1
通讯作者：
Zhang, Ruifu
中科院分区：
文献类型：
--
作者：
Miao, Youzhi;Li, Pan;Zhang, Ruifu
木质纤维素的顽固性对化学或生物燃料工业中木质纤维素生物质的生物转化形成了强大的障碍。丝状真菌是植物生物量的主要分解者，能够形成所有必需的酶。在这里，他们从一种优质的生物质降解菌株烟曲霉Z5中鉴定了GH10和GH11内切木聚糖酶和CE1乙酰木聚糖酯酶（Axe1），并研究了它们如何在木聚糖降解中相互作用。纤维素结合（CBM1）结构域抑制纯木聚糖的GH10木聚糖酶活性，但使其具有水解水洗玉米芯颗粒（WCCP）的能力。含有CBM1的GH10木聚糖酶在WCCP水解过程中也与含有CBM1的Axe1表现出协同作用，这种协同作用严格依赖于它们的CBM1结构域的存在。GH11木聚糖酶没有CBM1，但仍能结合木聚糖和水解WCCP；但与Axe1无协同作用。GH10木聚糖酶和GH11木聚糖酶在WCCP水解中表现出明显的协同作用，这取决于GH10木聚糖酶中CBM1的存在和GH11木聚糖酶的缺失。它们表现出与纤维素和木聚糖结合的不同机制，并在这两种结构完整时协同作用。这些发现将有助于进一步开发用于木质纤维素生物质转化的高效酶混合物。
The recalcitrance of lignocellulose forms a strong barrier for the bioconversion of lignocellulosic biomass in chemical or biofuel industries. Filamentous fungi are major plant biomass decomposer, and capable of forming all the required enzymes. Here, they characterized the GH10 and GH11 endo-xylanases and a CE1 acetyl-xylan esterase (Axe1) from a superior biomass-degrading strain, Aspergillus fumigatus Z5, and examined how they interact in xylan degradation. Cellulose-binding (CBM1) domain inhibited GH10 xylanase activities for pure xylan, but afforded them an ability to hydrolyze washed corncob particles (WCCP). CBM1-containing GH10 xylanases also showed synergism with CBM1-containing Axe1 in WCCP hydrolysis, and this synergy was strictly dependent on the presence of their CBM1 domains. In contrast, GH11 xylanases had no CBM1, but still could bind xylan and hydrolyzed WCCP; however, no synergism displayed with Axe1. GH10 xylanases and GH11 xylanases showed a pronounced synergism in WCCP hydrolysis, which was dependent on the presence of the CBM1 in GH10 xylanases and absence from GH11 xylanases. They exhibit different mechanisms to bind to cellulose and xylan, and act in synergy when these two structures are intact. These findings will be helpful for the further development of highly efficient enzyme mixtures for lignocellulosic biomass conversion.