13TSB_CRD - Flexible Engineered Solutions for Xylose Metabolism Using Synthetic Biology (FLEX)

13TSB_CRD - 使用合成生物学 (FLEX) 的木糖代谢灵活工程解决方案

• 批准号: BB/L011522/1
• 负责人: Gavin Thomas
• 金额: $ 14.1万
• 依托单位: University of York
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FL011522%2F1
• 关键词: 13TSB_CRD; Flexible; Engineered; Solutions; Xylose

The development of biofuels to replace our reliance on petrochemical-based fuels is a challenging economic problem. Basic science can make significant contributions to this problem by making the process more efficient and hence more economically competitive. The replacement of starch-based feedstock for the production of biofuels like biobutanol with more sustainable lignocellulose-based material is challenging due to the complexity of this material to efficient breakdown into forms that can used by the biofuel producing bacteria. In this project we wish to use new synthetic biology methods to engineer a whole new biological property into two biotechnologically important bacteria, namely the ability to grow on hemicellulose-derived xylo-oligomers. The formation of xylo-oligomers such as xylotetraose (X4), xylotriose (x3) and xylobiose(X2) occurs during the enzymatic breakdown of the hemicelluloses by xylanases. Further breakdown to the monosaccharide xylose (X1) requires the action of beta-xylosidases and then the free xylose is transported into bacterial cell via active transporters. The utilisation of the xylose monosaccharide has been the focus on most attention in the engineering of microbes for efficient hemicelluloses utilisation and the use of the xylo-oligomers directly has not been considered very widely. In this project we wish to engineer bacteria to use this material more efficiently. By using transporters for X2-X4, which take up one of these molecules for one unit of energy, the bacteria are much more efficient than those which have to each 2-4 units of energy to take up the same amount of sugar present in the monomeric form. There is no energetic costs to break down the X2-X4 to X1 on the inside. Bacteria growing under anaerobic fermentatative conditions used to make biobutanol are energy limited and so this will make a demonstrable increase in their growth rates as oligo-xylans are the primary carbon source available when growing on hemi-cellulose and hence these reactions have high flux. We will also investigate using a more efficient secondary transporter versus a primary ABC transporter to further improve growth yields. At a bioprocess level the use of xylo-oligomers rather than the fully hydrolysed xylose allow the use of milder chemical hydrolysis steps in the hemicelluloses pretreatment which also results in lower rates of production of chemicals that subsequently inhibit the fermentation. The xylo-oligomer clusters, Xylo4, will be created and tested in Escherichia coli and then transferred to industrial Clostridium strains used by Green Biologics that are currently being used in China by partners of Green Biologics to make butanol from lignocellulose.

发展生物燃料以取代我们对石化燃料的依赖是一个具有挑战性的经济问题。基础科学可以使这一过程更有效率，从而在经济上更具竞争力，从而对这一问题作出重大贡献。用更可持续的木质纤维素基材料替代生产生物丁醇等生物燃料的淀粉基原料是具有挑战性的，因为这种材料的复杂性，无法有效地分解成生物燃料生产细菌可以使用的形式。在这个项目中，我们希望使用新的合成生物学方法来设计两种生物技术上重要的细菌的全新生物学特性，即在半纤维素衍生的低聚木糖上生长的能力。在木聚糖酶分解半纤维素的过程中，形成木糖低聚物，如木糖四糖（X4）、木糖三糖（x3）和木糖二糖（X2）。进一步分解为单糖木糖（X1）需要-木糖苷酶的作用，然后游离木糖通过活性转运体转运到细菌细胞中。木糖单糖的利用一直是半纤维素高效利用微生物工程研究的热点，而直接利用木糖低聚物的研究还不是很广泛。在这个项目中，我们希望设计细菌更有效地利用这种材料。通过使用X2-X4的转运体，细菌比那些需要2-4个单位能量才能吸收相同数量的糖的细菌效率要高得多。从内部将X2-X4分解为X1不需要耗费太多精力。在厌氧发酵条件下生长的细菌用于制造生物丁醇是能量有限的，因此这将使它们的生长速度明显增加，因为低聚木聚糖是在半纤维素上生长时可用的主要碳源，因此这些反应具有高通量。我们还将研究使用更有效的次级转运蛋白和初级ABC转运蛋白来进一步提高生长产量。在生物工艺水平上，使用低聚木糖而不是完全水解的木糖允许在半纤维素预处理中使用较温和的化学水解步骤，这也导致随后抑制发酵的化学物质的生产速率较低。这种木素低聚物簇Xylo4将在大肠杆菌中产生并进行测试，然后转移到绿色生物制品公司使用的工业梭状芽孢杆菌菌株上，绿色生物制品公司的合作伙伴目前正在中国使用这种菌株从木质纤维素中生产丁醇。

项目成果

Characterization of the l-arabinofuranose-specific GafABCD ABC transporter essential for l-arabinose-dependent growth of the lignocellulose-degrading bacterium Shewanella sp. ANA-3.

L-阿拉伯呋喃糖特异性GAFABCD ABC转运蛋白的表征对于木质纤维素降解细菌SHEWANELLA SP的L-阿拉伯糖依赖性生长必不可少的表征。 ana-3。

• DOI: 10.1099/mic.0.001308
• 发表时间: 2023-03
• 期刊: MICROBIOLOGY-SGM
• 影响因子: 2.8
• 作者: Drousiotis, Konstantinos;Herman, Reyme;Hawkhead, Judith;Leech, Andrew;Wilkinson, Anthony;Thomas, Gavin H
• 通讯作者: Thomas, Gavin H