Limitation of cellulose accessibility and unproductive binding of cellulases by pretreated sugarcane bagasse lignin.
Limitation of cellulose accessibility and unproductive binding of cellulases by pretreated sugarcane bagasse lignin.
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DOI：
10.1186/s13068-017-0860-7
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发表时间：
2017
影响因子：
6.3
通讯作者：
Milagres AMF
中科院分区：
文献类型：
--
作者：
Siqueira G;Arantes V;Saddler JN;Ferraz A;Milagres AMF
植物细胞壁中纤维素酶水解的有效性受到酶对纤维素的接触的强烈影响，这至少部分受到木质素的存在的限制。尽管酶催化之前的物理化学处理显着克服了这种顽固性，但残留的木质素仍然可以在该过程中发挥作用。木质素被认为充当屏障，阻碍纤维素并限制酶的进入。它还可以非特异性地结合纤维素酶，从而减少可作用于纤维素的酶的量。然而，预处理甘蔗渣中木质素的限制作用尚未完全了解。创建了一套经过五种领先预处理技术预处理的甘蔗渣，并用于评估其可及性和所得木质素的非生产性结合能力。蒸汽爆破和碱性亚硫酸盐预处理产生了更容易接触的底物，大约 90% 的纤维素使用高酶负载量进行了水解。经碱处理 (NaOH) 和蒸汽爆炸的甘蔗渣的酶水解受到测试的最低酶负载下的非生产性结合的强烈影响。对提取的木质素的分析证实了这些木质素的优异结合能力。与不含亚硫酸盐的类似预处理（碱性和酸性）相比，基于亚硫酸盐的预处理（碱性亚硫酸盐和酸性亚硫酸盐）产生的木质素结合能力较低。基于亚硫酸盐的预处理基材中存在的强酸基团归因于磺化木质素，证实了这些基材中存在的木质素的较低结合能力。更先进的酶制剂 (Cellic CTec3) 在低酶负载量下受无效结合的影响较小。为了降低蛋白质结合能力，需要进行增加可及性和修饰木质素的预处理。如果低酶负载量的水解是经济上可行的工艺的目标，那么寻找所谓的弱木质素结合酶就显得尤为重要。
The effectiveness of the enzymatic hydrolysis of cellulose in plant cell wall is strongly influenced by the access of enzymes to cellulose, which is at least in part limited by the presence of lignin. Although physicochemical treatments preceding the enzymatic catalysis significantly overcome this recalcitrance, the residual lignin can still play a role in the process. Lignin is suggested to act as a barrier, hindering cellulose and limiting the access of the enzymes. It can also unspecifically bind cellulases, reducing the amount of enzymes available to act on cellulose. However, the limiting role of the lignin present in pretreated sugarcane bagasses has not been fully understood yet. A set of sugarcane bagasses pretreated by five leading pretreatment technologies was created and used to assess their accessibility and the unproductive binding capacity of the resulting lignins. Steam explosion and alkaline sulfite pretreatments resulted in more accessible substrates, with approximately 90% of the cellulose hydrolyzed using high enzyme loadings. Enzymatic hydrolysis of alkaline-treated (NaOH) and steam-exploded sugarcane bagasses were strongly affected by unproductive binding at the lowest enzyme loading tested. Analysis of the extracted lignins confirmed the superior binding capacity of these lignins. Sulfite-based pretreatments (alkaline sulfite and acid sulfite) resulted in lignins with lower binding capacities compared to the analogue pretreatments without sulfite (alkaline and acidic). Strong acid groups present in sulfite-based pretreated substrates, attributed to sulfonated lignins, corroborated the lower binding capacities of the lignin present in these substrates. A more advanced enzyme preparation (Cellic CTec3) was shown to be less affected by unproductive binding at low enzyme loading. Pretreatments that increase the accessibility and modify the lignin are necessary in order to decrease the protein binding capacity. The search for the called weak lignin-binding enzymes is of major importance if hydrolysis with low enzyme loadings is the goal for economically viable processes.
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影响因子：
4.1
作者：
Berlin, Alex;Balakshin, Mikhail;Saddler, Jack
通讯作者：
Saddler, Jack
影响因子：
3.4
作者：
CHERNOGLAZOV, VM;ERMOLOVA, OV;KLYOSOV, AA
通讯作者：
KLYOSOV, AA
影响因子：
2.7
作者：
Chandra, Richard P.;Ewanick, Shannon M.;Saddler, Jack N.
通讯作者：
Saddler, Jack N.
影响因子：
6.1
作者：
Guerra, Anderson;Filpponen, Ilari;Argyropoulos, Dimitris S.
通讯作者：
Argyropoulos, Dimitris S.
DOI：
10.1038/nbt0285-155
发表时间：
1985-01-01
期刊：
BIO-TECHNOLOGY
影响因子：
--
作者：
GRETHLEIN, HE
通讯作者：
GRETHLEIN, HE