Improving Saccharomyces cerevisiae growth against lignocellulose-derived inhibitors as well as maximizing ethanol production by a combination proposal of γ-irradiation pretreatment with in situ detoxification
Improving Saccharomyces cerevisiae growth against lignocellulose-derived inhibitors as well as maximizing ethanol production by a combination proposal of γ-irradiation pretreatment with in situ detoxification
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DOI：
10.1016/j.cej.2015.10.086
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发表时间：
2016-03-01
影响因子：
15.1
通讯作者：
Fan, Lihai
中科院分区：
文献类型：
--
作者：
Liu, Yun;Zhou, Hua;Fan, Lihai
采用辐照预处理与原位脱毒、水漂洗、水/乙酸乙酯（2：8，v/v）接触、NaOH（1 mM，pH11.0）过灰和NaBH 4（20 mM）还原4种组合策略解决了乙醇发酵中的毒性难题。采用FT-IR、SEM和AFM对辐照后的秸秆进行了表征。用GC-MS分析预处理过程中形成的辐射介导的抑制剂的组成。脱毒的稻草（200 gDS/L）用通过3因素混合物设计优化的酶混合物（类似于1 mg蛋白质/gDS）水解。利用酿酒酵母分别采用水解发酵和同步糖化发酵两种方法将水解液转化为乙醇。结果表明，葡萄糖得率在60%~ 80%之间，木糖得率在40%~ 60%之间。酵母生长、残余葡萄糖和乙醇产率随组合方法而变化。无论SHF还是SSF，辐照预处理与NaBH 4解毒相结合的组合方案均获得了最高的葡萄糖生物转化率（99.7%）和乙醇产率（70%）。结果表明，辐照预处理与NaBH 4原位脱毒相结合的方法是一种很有前途的木质纤维素生物质乙醇生产方法。(C)2015 Elsevier B. V.版权所有。
Four combined strategies of irradiation pretreatment with in situ detoxification, H2O rinsing, H2O/ethyl acetate (2:8, v/v) contacting, NaOH (1 mM, pH 11.0) overliming and NaBH4 (20 mM) reduction, were conducted to solve the toxicity dilemma in ethanol fermentation. The irradiated straw was characterized by FT-IR, SEM and AFM. The compositions of irradiation-mediated inhibitors formed during pretreatment were analyzed with GC-MS. The detoxified straw (200 gDS/L) was hydrolyzed with enzymes cocktails (similar to 1 mg protein/gDS) optimized by a 3-factor mixture design. The hydrolysate was bioconverted to ethanol with separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) using Saccharomyces cerevisiae. Results showed that glucose yield varied from 60% to 80% and xylose yield from 40% to 60% in dependence on detoxification methods. Yeast growth, residual glucose and ethanol yield varied with the combination approaches. The highest glucose bioconversion (99.7%) and ethanol yield (70%) were achieved via the combined proposal of irradiation pretreatment with NaBH4 detoxification regardless of SHF and SSF. The findings revealed that the combination proposal of irradiation pretreatment with NaBH4 detoxification in situ would be a promising alternative method for bioethanol production from liginocellulosic biomass. (C) 2015 Elsevier B.V. All rights reserved.