State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China.
Biotechnol Biofuels. 2012 Sep 21;5(1):72. doi: 10.1186/1754-6834-5-72.
As one of the best xylose utilization microorganisms, Scheffersomyces stipitis exhibits great potential for the efficient lignocellulosic biomass fermentation. Therefore, a comprehensive understanding of its unique physiological and metabolic characteristics is required to further improve its performance on cellulosic ethanol production.
A constraint-based genome-scale metabolic model for S. stipitis CBS 6054 was developed on the basis of its genomic, transcriptomic and literature information. The model iTL885 consists of 885 genes, 870 metabolites, and 1240 reactions. During the reconstruction process, 36 putative sugar transporters were reannotated and the metabolisms of 7 sugars were illuminated. Essentiality study was conducted to predict essential genes on different growth media. Key factors affecting cell growth and ethanol formation were investigated by the use of constraint-based analysis. Furthermore, the uptake systems and metabolic routes of xylose were elucidated, and the optimization strategies for the overproduction of ethanol were proposed from both genetic and environmental perspectives.
Systems biology modelling has proven to be a powerful tool for targeting metabolic changes. Thus, this systematic investigation of the metabolism of S. stipitis could be used as a starting point for future experiment designs aimed at identifying the metabolic bottlenecks of this important yeast.
作为利用木糖的最佳微生物之一，毕赤酵母在高效木质纤维素生物质发酵方面具有巨大的潜力。因此，需要全面了解其独特的生理和代谢特性，以进一步提高其在纤维素乙醇生产中的性能。
在毕赤酵母 CBS 6054 的基因组、转录组和文献信息的基础上，构建了基于约束的基因组规模代谢模型 iTL885。该模型包含 885 个基因、870 种代谢物和 1240 个反应。在重构过程中，重新注释了 36 个假定的糖转运蛋白，并阐明了 7 种糖的代谢途径。在不同的生长培养基上进行了必需性研究，以预测必需基因。利用约束性分析研究了影响细胞生长和乙醇形成的关键因素。此外，阐明了木糖的摄取系统和代谢途径，并从遗传和环境的角度提出了提高乙醇产量的优化策略。
系统生物学模型已被证明是靶向代谢变化的有力工具。因此，对毕赤酵母代谢的系统研究可以作为未来旨在确定这种重要酵母代谢瓶颈的实验设计的起点。
