Metabolic pathway engineering based on metabolomics confers acetic and formic acid tolerance to a recombinant xylose-fermenting strain of Saccharomyces cerevisiae.
Metabolic pathway engineering based on metabolomics confers acetic and formic acid tolerance to a recombinant xylose-fermenting strain of Saccharomyces cerevisiae.
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基于代谢组学的代谢途径工程赋予乙糖酵母的重组二甲糖发酵菌株的乙酸和甲酸耐受性。
DOI：
10.1186/1475-2859-10-2
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发表时间：
2011-01-10
影响因子：
6.4
通讯作者：
Kondo A
中科院分区：
文献类型：
--
作者：
Hasunuma T;Sanda T;Yamada R;Yoshimura K;Ishii J;Kondo A
开发对木质纤维素水解产物中的抑制剂具有增加的耐受性的新型酵母菌株对于生物乙醇的生产是高度期望的。在木质纤维素的预处理（即增溶和水解）过程中必然会释放出弱有机酸如乙酸和甲酸，这对微生物生长和乙醇生产产生负面影响。然而，由于毒性的模式是复杂的，基因工程策略解决酵母耐受弱有机酸一直很少见。因此，加强基础研究有望确定提高弱酸耐受性的靶基因。在这项研究中，乙酸对木糖发酵的影响进行了分析，通过检查代谢产物的重组木糖发酵菌株的酿酒酵母。代谢物组学分析显示，通过添加乙酸盐，参与非氧化戊糖磷酸途径（PPP）的代谢物[例如景天庚酮糖-7-磷酸、核酮糖-5-磷酸、核糖-5-磷酸和赤藓糖-4-磷酸]显著蓄积，表明乙酸可能减缓该途径的通量。因此，编码PPP相关酶、转醛醇酶或转酮醇酶的基因在木糖发酵酵母中过表达，这成功地赋予了在乙酸和甲酸存在下增加的乙醇生产率。我们的代谢组学方法揭示了一个潜在的乙酸反应的分子事件，并将注意力集中在非氧化PPP作为代谢工程的目标。代谢工程的一个重要挑战是鉴定具有物质重要性的基因靶标。这项研究表明，代谢组学是一个强大的工具，制定合理的战略，赋予耐受压力，通过基因工程。
The development of novel yeast strains with increased tolerance toward inhibitors in lignocellulosic hydrolysates is highly desirable for the production of bio-ethanol. Weak organic acids such as acetic and formic acids are necessarily released during the pretreatment (i.e. solubilization and hydrolysis) of lignocelluloses, which negatively affect microbial growth and ethanol production. However, since the mode of toxicity is complicated, genetic engineering strategies addressing yeast tolerance to weak organic acids have been rare. Thus, enhanced basic research is expected to identify target genes for improved weak acid tolerance. In this study, the effect of acetic acid on xylose fermentation was analyzed by examining metabolite profiles in a recombinant xylose-fermenting strain of Saccharomyces cerevisiae. Metabolome analysis revealed that metabolites involved in the non-oxidative pentose phosphate pathway (PPP) [e.g. sedoheptulose-7-phosphate, ribulose-5-phosphate, ribose-5-phosphate and erythrose-4-phosphate] were significantly accumulated by the addition of acetate, indicating the possibility that acetic acid slows down the flux of the pathway. Accordingly, a gene encoding a PPP-related enzyme, transaldolase or transketolase, was overexpressed in the xylose-fermenting yeast, which successfully conferred increased ethanol productivity in the presence of acetic and formic acid. Our metabolomic approach revealed one of the molecular events underlying the response to acetic acid and focuses attention on the non-oxidative PPP as a target for metabolic engineering. An important challenge for metabolic engineering is identification of gene targets that have material importance. This study has demonstrated that metabolomics is a powerful tool to develop rational strategies to confer tolerance to stress through genetic engineering.
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影响因子：
3.4
作者：
Helle, S;Cameron, D;Duff, S
通讯作者：
Duff, S
影响因子：
7.4
作者：
Canelas, Andre B.;ten Pierick, Angela;Heijnen, Joseph J.
通讯作者：
Heijnen, Joseph J.
影响因子：
3
作者：
AARNIO, TH;SUIHKO, ML;KAUPPINEN, VS
通讯作者：
KAUPPINEN, VS
影响因子：
3.4
作者：
Larsson, S;Palmqvist, E;Nilvebrant, NO
通讯作者：
Nilvebrant, NO
影响因子：
4.4
作者：
Jin, YS;Alper, H;Stephanopoulos, G
通讯作者：
Stephanopoulos, G