• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied and Environmental Microbiology >Reconstruction of an Acetogenic 2,3-Butanediol Pathway Involving a Novel NADPH-Dependent Primary-Secondary Alcohol Dehydrogenase
【24h】

Reconstruction of an Acetogenic 2,3-Butanediol Pathway Involving a Novel NADPH-Dependent Primary-Secondary Alcohol Dehydrogenase

机译：涉及新的NADPH依赖的伯-仲醇脱氢酶的产乙酸2，3-丁二醇途径的重建。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Acetogenic bacteria use CO and/or CO2 plus H2 as their sole carbon and energy sources. Fermentation processes with these organisms hold promise for producing chemicals and biofuels from abundant waste gas feedstocks while simultaneously reducing industrial greenhouse gas emissions. The acetogen Clostridium autoethanogenum is known to synthesize the pyruvate-derived metabolites lactate and 2,3-butanediol during gas fermentation. Industrially, 2,3-butanediol is valuable for chemical production. Here we identify and characterize the C. autoethanogenum enzymes for lactate and 2,3-butanediol biosynthesis. The putative C. autoethanogenum lactate dehydrogenase was active when expressed in Escherichia coli. The 2,3-butanediol pathway was reconstituted in E. coli by cloning and expressing the candidate genes for acetolactate synthase, acetolactate decarboxylase, and 2,3-butanediol dehydrogenase. Under anaerobic conditions, the resulting E. coli strain produced 1.1 ± 0.2 mM 2R,3R-butanediol (23 μM h?1 optical density unit?1), which is comparable to the level produced by C. autoethanogenum during growth on CO-containing waste gases. In addition to the 2,3-butanediol dehydrogenase, we identified a strictly NADPH-dependent primary-secondary alcohol dehydrogenase (CaADH) that could reduce acetoin to 2,3-butanediol. Detailed kinetic analysis revealed that CaADH accepts a range of 2-, 3-, and 4-carbon substrates, including the nonphysiological ketones acetone and butanone. The high activity of CaADH toward acetone led us to predict, and confirm experimentally, that C. autoethanogenum can act as a whole-cell biocatalyst for converting exogenous acetone to isopropanol. Together, our results functionally validate the 2,3-butanediol pathway from C. autoethanogenum, identify CaADH as a target for further engineering, and demonstrate the potential of C. autoethanogenum as a platform for sustainable chemical production.
机译：产乙酸细菌使用CO和/或CO2加H2作为唯一碳和能源。这些生物的发酵过程有望从丰富的废气原料生产化学物质和生物燃料，同时减少工业温室气体的排放。众所周知，产乙酸产乙醇梭菌会在气体发酵过程中合成丙酮酸衍生的代谢产物乳酸和2,3-丁二醇。在工业上，2，3-丁二醇对于化学生产是有价值的。在这里，我们确定和表征乳酸和2,3-丁二醇生物合成的C. autoethanogenum酶。当在大肠杆菌中表达时，假定的自身乙醇酸梭菌乳酸脱氢酶是有活性的。通过克隆并表达乙酰乳酸合酶，乙酰乳酸脱羧酶和2,3-丁二醇脱氢酶的候选基因，在大肠杆菌中重建了2,3-丁二醇途径。在厌氧条件下，所得的大肠杆菌菌株产生1.1±0.2 mM 2R，3R-丁二醇（23μMh？1光密度单位？1），与自含碳梭菌在含CO的生长过程中产生的水平相当。废气。除了2,3-丁二醇脱氢酶，我们还确定了严格的NADPH依赖型伯-仲醇脱氢酶（CaADH），可以将丙酮酸还原为2,3-丁二醇。详细的动力学分析表明，CaADH可以接受一系列2-，3-和4-碳底物，包括非生理酮丙酮和丁酮。 CaADH对丙酮的高活性使我们能够预测并通过实验证实，自产乙醇梭菌可以充当将外源丙酮转化为异丙醇的全细胞生物催化剂。在一起，我们的结果在功能上验证了自产乙醇梭菌的2,3-丁二醇途径，确定了CaADH作为进一步工程化的目标，并证明了自生乙醇梭菌作为可持续化学生产平台的潜力。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号