Prospection and Evaluation of (Hemi) Cellulolytic Enzymes Using Untreated and Pretreated Biomasses in Two Argentinean Native Termites.
Prospection and Evaluation of (Hemi) Cellulolytic Enzymes Using Untreated and Pretreated Biomasses in Two Argentinean Native Termites.
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DOI：
10.1371/journal.pone.0136573
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Talia P
中科院分区：
文献类型：
--
作者：
Ben Guerrero E;Arneodo J;Bombarda Campanha R;Abrão de Oliveira P;Veneziano Labate MT;Regiani Cataldi T;Campos E;Cataldi A;Labate CA;Martins Rodrigues C;Talia P
在阿根廷和巴西，蔗渣(俗称：甘蔗渣)和狼尾草(又称纳皮尔草)是最有希望生产生物乙醇的原料。在这项研究中，这两种生物量在酸预处理前后和在用纳氏白蚁和白蚁肠道消化器进行水解后进行了评估。稀酸处理后生物质的化学成分分析表明，半纤维素部分被去除。对白蚁肠道匀浆在处理和未处理的生物质中培养上清液中的(半)纤维分解活性进行了评价。在所有情况下，我们检测到与未经处理的生物质、羧甲基纤维素和木聚糖相比，使用预处理的生物质的内切葡聚糖酶和木聚糖酶活性明显更高。在酶谱和双向凝胶电泳中检测到几条具有(半)纤维分解活性的蛋白条带。这些条带或斑点的部分蛋白质经质谱仪鉴定为木聚糖多肽。最后，分析了与两种阿根廷本地白蚁相关的培养的纤维素分解细菌内共生菌的多样性。本研究首次描述了两种阿根廷本地白蚁的细菌内共生体和内源(半)纤维素酶，以及它们在降解木质纤维素生物质生产生物乙醇方面的潜在应用。
Saccharum officinarum bagasse (common name: sugarcane bagasse) and Pennisetum purpureum (also known as Napier grass) are among the most promising feedstocks for bioethanol production in Argentina and Brazil. In this study, both biomasses were assessed before and after acid pretreatment and following hydrolysis with Nasutitermes aquilinus and Cortaritermes fulviceps termite gut digestome. The chemical composition analysis of the biomasses after diluted acid pretreatment showed that the hemicellulose fraction was partially removed. The (hemi) cellulolytic activities were evaluated in bacterial culture supernatants of termite gut homogenates grown in treated and untreated biomasses. In all cases, we detected significantly higher endoglucanase and xylanase activities using pretreated biomasses compared to untreated biomasses, carboxymethylcellulose and xylan. Several protein bands with (hemi) cellulolytic activity were detected in zymograms and two-dimensional gel electrophoresis. Some proteins of these bands or spots were identified as xylanolytic peptides by mass spectrometry. Finally, the diversity of cultured cellulolytic bacterial endosymbionts associated to both Argentinean native termite species was analyzed. This study describes, for the first time, bacterial endosymbionts and endogenous (hemi) cellulases of two Argentinean native termites as well as their potential application in degradation of lignocellulosic biomass for bioethanol production.