AA16, a new lytic polysaccharide monooxygenase family identified in fungal secretomes
AA16, a new lytic polysaccharide monooxygenase family identified in fungal secretomes
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DOI：
10.1186/s13068-019-1394-y
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发表时间：
2019-03-16
影响因子：
6.3
通讯作者：
Berrin, Jean-Guy
中科院分区：
文献类型：
--
作者：
Filiatrault-Chastel, Camille;Navarro, David;Berrin, Jean-Guy
研究背景木质纤维素生物质被认为是一种很有前途的替代化石资源的燃料、材料和化学品的生产。需要高效的酶系统来降解植物细胞壁并克服其不稳定性。一种广泛使用的纤维素分解混合物的生产者是子囊菌里氏木霉，但这种生物体分泌一组有限的酶。为提高糖化得率，一种策略是提高T。reesei酶鸡尾酒与其他生物质降解丝状真菌产生的酶分离的生物多样性。结果在这项研究中，酶鸡尾酒分泌的五个菌株从曲霉属（曲霉菌株BRFM 405，1487，1489，1490和尼日尔曲霉菌株BRFM 430）进行了测试，他们的能力，以提高T。reesei参考混合物用于预处理生物质的糖化。真菌分泌物的蛋白质组学分析，显着提高生物质降解表明，存在的蛋白质属于一个假定的LPMO家族先前确定的基因组分析和等待实验证明的活动。这个新的LPMO家族的成员，命名为AA16，在真菌和卵菌中遇到的生活方式面向与植物生物量的相互作用。利用毕赤酵母（Pichia pastoris）高效表达棘孢曲霉（Aspergillus aculeatus）的AA16蛋白（AaAA16）。LPMO型酶的活性被证明在纤维素与氧化裂解在C1位置的葡萄糖单元。AaAA16 LPMO能显著提高T. reesei CBHI对纤维素底物的影响。已经研究了几十年，他们的CAZymes多样性，我们确定了一个新的真菌LPMO家族的成员，使用分泌组学和功能测定。本文所表征的AA16家族的创始成员的性质对于用于生物精炼可能是令人感兴趣的。
BackgroundLignocellulosic biomass is considered as a promising alternative to fossil resources for the production of fuels, materials and chemicals. Efficient enzymatic systems are needed to degrade the plant cell wall and overcome its recalcitrance. A widely used producer of cellulolytic cocktails is the ascomycete Trichoderma reesei, but this organism secretes a limited set of enzymes. To improve the saccharification yields, one strategy is to upgrade the T. reesei enzyme cocktail with enzymes produced by other biomass-degrading filamentous fungi isolated from biodiversity.ResultsIn this study, the enzymatic cocktails secreted by five strains from the genus Aspergillus (Aspergillus japonicus strains BRFM 405, 1487, 1489, 1490 and Aspergillus niger strain BRFM 430) were tested for their ability to boost a T. reesei reference cocktail for the saccharification of pretreated biomass. Proteomic analysis of fungal secretomes that significantly improved biomass degradation showed that the presence of proteins belonging to a putative LPMO family previously identified by genome analysis and awaiting experimental demonstration of activity. Members of this novel LPMO family, named AA16, are encountered in fungi and oomycetes with life styles oriented toward interactions with plant biomass. One AA16 protein from Aspergillus aculeatus (AaAA16) was produced to high level in Pichia pastoris. LPMO-type enzyme activity was demonstrated on cellulose with oxidative cleavage at the C1 position of the glucose unit. AaAA16 LPMO was found to significantly improve the activity of T. reesei CBHI on cellulosic substrates.ConclusionsAlthough Aspergillus spp. has been investigated for decades for their CAZymes diversity, we identified members of a new fungal LPMO family using secretomics and functional assays. Properties of the founding member of the AA16 family characterized herein could be of interest for use in biorefineries.