Designing simultaneous saccharification and fermentation for improved xylose conversion by a recombinant strain of Saccharomyces cerevisiae
Designing simultaneous saccharification and fermentation for improved xylose conversion by a recombinant strain of Saccharomyces cerevisiae
复制标题
DOI：
10.1016/j.jbiotec.2008.01.004
复制
发表时间：
2008-03-20
影响因子：
4.1
通讯作者：
Liden, Gunnar
中科院分区：
文献类型：
--
作者：
Olofsson, Kim;Rudolf, Andreas;Liden, Gunnar
小麦秸秆是一种资源丰富的农业废弃物，可作为生产生物乙醇的原料。由于小麦秸秆中的高木聚糖含量，木糖和葡萄糖的发酵对于满足所需的乙醇总产率至关重要。在本工作中，将在小麦秸秆水解液上好氧培养的酿酒酵母（Saccharomycescerevisiae）的重组木糖发酵菌株TMB 3400用于蒸汽预处理的小麦秸秆的同时糖化发酵（SSF）。研究了发酵策略和温度对木糖消耗、乙醇生成和副产物生成的影响。此外，还进行了模拟固态发酵实验，进一步研究了温度对木糖发酵及副产物形成的影响。特别是对于SSF，在测试的纤维含量的最高值（9%水不溶性物质）下。WIS），发现补料分批策略在乙醇产率方面明显上级分批方法，其中补料分批给出理论产率的71%（基于所有可用糖），而分批仅为59%。在7%的WIS含量下获得了接近80%的更高的乙醇产率。木糖发酵对乙醇总产量有显著贡献。发现在30-37 ° C范围内的温度的选择是重要的，特别是在较高含量的水不溶性固体（WIS）时。研究的原料和酵母菌株的最佳温度为34 ℃。模型SSF实验与确定的培养基显示强烈的温度影响木糖摄取速率和木糖醇产量。(C)2008 Elsevier B. V.保留所有权利。
Wheat straw is an abundant agricultural residue which can be used as a raw material for bioethanol production. Due to the high xylan content in wheat straw, fermentation of both xylose and glucose is crucial to meet desired overall yields of ethanol. in the present work a recombinant xylose fermenting strain of Saccharomyces cerevisiae, TMB3400, cultivated aerobically on wheat straw hydrolysate, was used in simultaneous saccharification and fermentation (SSF) of steam pretreated wheat straw. The influence of fermentation strategy and temperature was studied in relation to xylose consumption, ethanol formation and by-product formation. In addition, model SSF experiments were made to further investigate the influence of temperature on xylose fermentation and by-product formation. In particular for SSF at the highest value of fibre content tested (9% water insoluble substance. WIS), it was found that a fed-batch strategy was clearly superior to the batch process in terms of ethanol yield, where the fed-batch gave 71% of the theoretical yield (based on all available sugars) in comparison to merely 59% for the batch. Higher ethanol yields, close to 80%, were obtained at a WIS-content of 7%. Xylose fermentation significantly contributed to the overall ethanol yields. The choice of temperature in the range 30-37 degrees C was found to be important, especially at higher contents of water insoluble solids (WIS). The optimum temperature was found to be 34 degrees C for the raw material and yeast strain studied. Model SSF experiments with defined medium showed strong temperature effects on the xylose uptake rate and xylitol yield. (C) 2008 Elsevier B.V. All rights reserved.