循環農業：農業廢棄物再資源化【生命科學系/黃介辰特聘教授】
| 論文篇名 | Utilization of Monosaccharides by Hungateiclostridium thermocellum ATCC 27405 through Adaptive Evolution |
| 期刊名稱 | Microorganisms |
| 發表年份,卷數,起迄頁數 | 2021, 9(7): 1445 |
| 作者 | Dung Minh Ha-Tran; Trinh Thi My Nguyen; Lo, Shou-Chen*; Huang, Chieh-Chen(黃介辰)* |
| DOI | 10.3390/microorganisms9071445 |
| 英文摘要 | Hungateiclostridium thermocellum ATCC 27405 is a promising bacterium for consolidated bioprocessing with a robust ability to degrade lignocellulosic biomass through a multienzyme cellulosomal complex. The bacterium uses the released cellodextrins, glucose polymers of different lengths, as its primary carbon source and energy. In contrast, the bacterium exhibits poor growth on monosaccharides such as fructose and glucose. This phenomenon raises many important questions concerning its glycolytic pathways and sugar transport systems. Until now, the detailed mechanisms of H. thermocellum adaptation to growth on hexose sugars have been relatively poorly explored. In this study, adaptive laboratory evolution was applied to train the bacterium in hexose sugars-based media, and genome resequencing was used to detect the genes that got mutated during adaptation period. RNA-seq data of the first culture growing on either fructose or glucose revealed that several glycolytic genes in the Embden–Mayerhof–Parnas pathway were expressed at lower levels in these cells than in cellobiose-grown cells. After seven consecutive transfer events on fructose and glucose (~42 generations for fructose-adapted cells and ~40 generations for glucose-adapted cells), several genes in the EMP glycolysis of the evolved strains increased the levels of mRNA expression, accompanied by a faster growth, a greater biomass yield, a higher ethanol titer than those in their parent strains. Genomic screening also revealed several mutation events in the genomes of the evolved strains, especially in those responsible for sugar transport and central carbon metabolism. Consequently, these genes could be applied as potential targets for further metabolic engineering to improve this bacterium for bio-industrial usage. |
| 發表成果與本中心研究主題相關性 | 菌株Hungateiclostridium thermocellum ATCC 27405經過適應性演化具有應用於農業廢棄物生產生質能之潛力。 |
