Enhancing Prehydrolysates Fermentability by Adding Nucleophilic Amino Acids and Proteins in Biomass Pretreatment,ACS Sustainable Chemistry & Engineering

当前位置： X-MOL 学术 › ACS Sustain. Chem. Eng. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Enhancing Prehydrolysates Fermentability by Adding Nucleophilic Amino Acids and Proteins in Biomass Pretreatment
ACS Sustainable Chemistry & Engineering ( IF 7.1 ) Pub Date : 2020-05-07 , DOI: 10.1021/acssuschemeng.0c01086
Yequan Sheng _{1,

2,

3} , Yu Zhang ₄ , Hongzhi Ma ₅ , Yong Xu _{1,

2,

3} , Maobing Tu ₄

Affiliation

Dilute acid pretreatment produced a considerable amount of carbonyl compounds in the biomass prehydrolysates, which significantly inhibited the sequential microbial fermentation. To reduce the release of carbonyl inhibitors, a novel approach of pretreatment with amino acids and proteins has been developed to improve the fermentability of prehydrolysates. Four percent (w/w) of cysteine (Cys), histidine (His), soy protein isolate (SPI), and bovine serum albumin (BSA) was added into dilute acid pretreatment of aspen (DAPA). The resulted prehydrolysates were fermented by Saccharomyces cerevisiae, and the glucose consumption rate in the prehydrolysates was increased from 0.32 to 1.35, 3.22, 1.02, and 1.61 g/L/h, respectively. The pretreated substrates were applied to enzymatic hydrolysis. Unexpectedly, it was observed that 72 h hydrolysis yields of DAPA-Cys and DAPA-His decreased from 71.35% (DAPA) to 63.93% and 28.11%, respectively, while the 72 h hydrolysis yield of DAPA-SPI increased to 75.04%, and the 72 hydrolysis yield of DAPA-BSA did not change. The results showed that BSA was the most effective additive to enhance the prehydrolysate fermentability. It increased the ethanol productivity of prehydrolysates from 0.15 (without addition) to 0.77 g/L/h. The final yield was promoted from 0.05 to 0.44 g/g glucose. In addition, a total of 22 potential inhibitors in prehydrolysates have been identified and quantified by gas chromatography/mass spectrometry (GC/MS). The results showed that addition of histidine in pretreatment reduced inhibitors much more than addition of cysteine, SPI, and BSA. The results suggests that addition of protein decreases inhibitors by reaction with aldehydes/ketones and also by buffering and reducing pretreatment severity, which results in less inhibitors produced. The reduced severity also decreases the cellulose digestibility, especially with the addition of cysteine and histidine. Hence, the overall effect on yield and productivity is a trade-off between the positive effect of reducing inhibitors and the undesirable effect of less sugar release from the substrates.

中文翻译：

通过在生物质预处理中添加亲核氨基酸和蛋白质增强预水解产物的发酵能力

稀酸预处理在生物质预水解物中产生了大量的羰基化合物，这大大抑制了后续的微生物发酵。为了减少羰基抑制剂的释放，已经开发了一种用氨基酸和蛋白质进行预处理的新方法来改善预水解产物的发酵能力。将4％（w / w）的半胱氨酸（Cys），组氨酸（His），大豆分离蛋白（SPI）和牛血清白蛋白（BSA）添加到白杨的稀酸预处理（DAPA）中。所产生的预水解产物通过酿酒酵母进行发酵。，预水解物中的葡萄糖消耗率分别从0.32增加到1.35、3.22、1.02和1.61 g / L / h。将预处理的底物用于酶促水解。出乎意料的是，观察到DAPA-Cys和DAPA-His的72 h水解产率分别从71.35％（DAPA）降至63.93％和28.11％，而DAPA-SPI的72 h水解产率增加至75.04％，并且DAPA-BSA的72水解率没有变化。结果表明，BSA是增强预水解产物发酵能力的最有效添加剂。它将预水解产物的乙醇生产率从0.15（无添加）提高到0.77 g / L / h。最终产量从0.05升至0.44 g / g葡萄糖。此外，通过气相色谱/质谱（GC / MS）鉴定并定量了预水解物中的22种潜在抑制剂。结果表明，在预处理中添加组氨酸比添加半胱氨酸，SPI和BSA可以减少更多的抑制剂。结果表明，蛋白质的添加通过与醛/酮反应以及通过缓冲和降低预处理的严重性来减少抑制剂，这导致产生的抑制剂减少。降低的严重性还降低了纤维素的消化率，尤其是添加了半胱氨酸和组氨酸后。因此，对产量和生产率的总体影响是还原抑制剂的积极作用与糖从底物释放的不良影响之间的权衡。结果表明，在预处理中添加组氨酸比添加半胱氨酸，SPI和BSA可以减少更多的抑制剂。结果表明，蛋白质的添加通过与醛/酮反应以及通过缓冲和降低预处理的严重性来减少抑制剂，这导致产生的抑制剂减少。降低的严重性还降低了纤维素的消化率，尤其是在添加半胱氨酸和组氨酸的情况下。因此，对产量和生产率的总体影响是还原抑制剂的积极作用与糖从底物释放的不良影响之间的权衡。结果表明，在预处理中添加组氨酸比添加半胱氨酸，SPI和BSA可以减少更多的抑制剂。结果表明，蛋白质的添加通过与醛/酮反应以及通过缓冲和降低预处理的严重性来减少抑制剂，这导致产生的抑制剂减少。降低的严重性还降低了纤维素的消化率，尤其是在添加半胱氨酸和组氨酸的情况下。因此，对产量和生产率的总体影响是还原抑制剂的积极作用与糖从底物释放的不良影响之间的权衡。结果表明，蛋白质的添加通过与醛/酮反应以及通过缓冲和降低预处理的严重性来减少抑制剂，这导致产生的抑制剂减少。降低的严重性还降低了纤维素的消化率，尤其是在添加半胱氨酸和组氨酸的情况下。因此，对产量和生产率的总体影响是还原抑制剂的积极作用与糖从底物释放的不良影响之间的权衡。结果表明，蛋白质的添加通过与醛/酮反应以及通过缓冲和降低预处理的严重性来减少抑制剂，这导致产生的抑制剂减少。降低的严重性还降低了纤维素的消化率，尤其是在添加半胱氨酸和组氨酸的情况下。因此，对产量和生产率的总体影响是还原抑制剂的积极作用与糖从底物释放的不良影响之间的权衡。

更新日期：2020-05-07

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南