摘要
The second generation bioethanol represents a main challenge in global efforts to utilize renewable resources rather than fossil fuels. However, the close association of cellulose and hemicelluloses to lignin in the plant cell wall makes it difficult to degrade lignocellulose into fermentable sugars. Consequently, pretreatments are necessary to make the polysaccharides more accessible to the enzymes, but the high temperature and extreme pH conditions required give rise to problems when using conventional enzymes in the saccharification step (Galbe and Zacchi 2002). Microorganisms thriving in habitats characterized by harsh conditions, and the enzymes derived therein, represent a helpful tool in the development of bioethanol production processes. In fact, they allow bioconversions at non-conventional conditions under which common biocatalysts are denatured. The use of high operational temperatures allows energy savings by reducing the cooling cost after high temperature pretreatments, and, in ethanol production, thermophilic conditions permit ethanol evaporation allowing harvest during fermentation.
摘要译文
第二代生物乙醇代表着全球努力利用可再生资源，而不是化石燃料的主要挑战。然而，纤维素和半纤维素，以木质素在植物细胞壁的密切关联使得难以降解木质纤维素成可发酵糖。因此，预处理是必要的，以使多糖更容易获得的酶，但在糖化步骤使用常规的酶时（Galbe和2002 Zacchi）所需的高温和极端pH条件引起的问题。微生物欣欣向荣的栖息地特征的条件苛刻，其中衍生的酶，代表了生物乙醇的生产工艺的开发一个有用的工具。事实上，它们允许生物转化在其下常见生物催化剂变性非常规条件。使用高的操作温度下使能量积蓄通过降低高温预处理后的冷却成本，并且，在乙醇生产，嗜热条件允许乙醇蒸发使发酵过程中的收获。
Beatrice Cobucci-Ponzano (1) Elena Ionata (1) Francesco La Cara (1) Alessandra Morana (1) Maria Carmina Ferrara (1) Luisa Maurelli (1) Andrea Strazzulli (1) Rosa Giglio (1) Marco Moracci (1). Extremophilic (Hemi)cellulolytic Microorganisms and Enzymes. Lignocellulose Conversion Enzymatic and Microbial Tools for Bioethanol Production[M].DE: Springer, 2013: 111-130