三羧酸循环

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浙工大柳志强等改造大肠杆菌高产 1,4-丁二醇
合成生物学与绿色生物制造· 2025-09-15 09:36
Core Viewpoint - The article discusses the advancements in the biosynthesis of 1,4-butanediol (BDO) through engineered Escherichia coli, highlighting the challenges and breakthroughs in creating a sustainable production method without antibiotics or inducers [2][3][7]. Group 1: BDO Production Challenges - BDO biosynthesis faces three main challenges: lack of natural BDO-producing microorganisms, significant carbon loss during synthesis, and high dependency on antibiotics and inducers, leading to increased costs [3]. Group 2: Engineering Breakthroughs - Researchers at Zhejiang University have developed a high-efficiency BDO synthesis strain by systematically engineering E. coli, resulting in a production of 0.1 g/L of BDO initially, which was later optimized to 0.82 g/L [6]. - The optimal enzyme combination for BDO production was identified, including enzymes from various bacteria, and a mutant enzyme variant was created that increased BDO yield by 11.19 times [6]. - By knocking out the pdhR gene, the researchers enhanced the conversion efficiency of pyruvate to acetyl-CoA, significantly reducing pyruvate accumulation and increasing BDO yield by 44% to 1.83 g/L [6]. Group 3: Antibiotic-Free Fermentation System - A significant advancement was the development of an antibiotic-free fermentation system, where the researchers utilized E. coli's native transcriptional regulatory elements to drive BDO synthesis without external inducers [7]. - The engineered strain B21-pT19 achieved a remarkable BDO production of 34.63 g/L in a 5 L reactor over 72 hours, maintaining stable yields across multiple fermentation batches without the need for antibiotics or inducers, marking the highest reported level of BDO production to date [7].
Cell子刊:异性同居,通过重塑肠道菌群,减轻肝损伤
生物世界· 2025-05-05 02:58
Core Viewpoint - The study highlights that cohabitation can reshape gut microbiota, specifically increasing the presence of Rikenella microfusus, which mitigates acute liver injury (ALI) and provides new scientific evidence for the prevention and treatment of ALI [2][3][5]. Group 1: Research Findings - Cohabitation leads to an increase in Rikenella microfusus, which reduces the severity of acute liver injury [5][7]. - Rikenella microfusus secretes β-galactosidase, enhancing the absorption of dietary isoflavone Bio-A, which plays a crucial role in liver protection [4][5]. - Bio-A interacts with pyruvate carboxylase (PC) and propionyl-CoA carboxylase α subunit (PCCA), boosting the tricarboxylic acid cycle and promoting the synthesis of protective glutathione in liver cells [4][5]. Group 2: Implications - The findings underscore the impact of microbiome composition on acute liver injury and the ability of isoflavone absorption to alleviate the severity of ALI [7]. - The research suggests a new connection between social behavior and health, indicating that regulating gut microbiota or supplementing specific metabolites could be a novel strategy for preventing and treating acute liver injury [7].