一碳化合物利用新途径的设计和体外构建  

A computationally designed pathway for one carbon compounds utilization and its in vitro construction

作　　者：陈阳 杨雪[1] 袁倩倩[1] 罗浩 李培顺[1] 马红武[1] 

机构地区：[1]中国科学院天津工业生物技术研究所,天津300308

出　　处：《生物加工过程》2017年第5期86-92,共7页Chinese Journal of Bioprocess Engineering

基　　金：天津科技支撑项目(14ZCZDSY00060);中国科学院重点研究项目(ZDRW-ZS-2016-3)

摘　　要：一碳化合物作为糖类的廉价替代底物在工业生物技术中具有广泛的应用前景。传统途径中由一碳化合物或糖类生产乙酰辅酶A衍生产品时会有1/3的碳损失,导致产品得率较低,因此找到没有碳损失的新途径非常重要。基于MetaCyc数据库的代谢反应集和通量平衡分析的途径分析方法,计算得到一条由一碳化合物甲醛生成乙酰辅酶A衍生产品的新途径,该途径不仅无碳损失,并且无能量(ATP)和还原力消耗。为了验证途径的可行性,筛选途径相关酶,纯化后进行体外实验,通过乙酸的产量来间接表征途径的运行情况。结果发现:乙酸的生成浓度会随着体系初始甲醛加入量的增加而增加,在一定条件下,乙酸的总碳摩尔得率可以达到90%,超过了传统路径的最大理论得率67%。C1 compounds can be widely used in industrial biotechnology as low-cost alternative substrates to sugars.In normal pathways for the synthesis of acetyl coenzyme A derived products from C1 compound, one third of the carbon atoms from the substrate is wasted as C〇 2,and thus the product yield is low. Therefore,it is important to find new carbon conserved synthesis pathways for acetyl-CoA derived products from C1 compounds.In this study,we built a large metabolic network based on reactions from MetaCyc database and used the flux balance analysis method to find a new pathway from formaldehyde to acetyl coenzyme A derived products.The new pathway is carbon conserved and ATP independent.We screened and purified the enzymes in the pathway and tested the pathway in vitro using acetate as the target product.The concentration of acetate produced from the system is enhanced with the increased addition of formaldehyde substrate.The carbon molar yield can achieve 90 % under certain conditions,exceeding the theoretical yield of 67 % from naturally existing pathways.

关 键 词：代谢网络模型 一碳化合物 乙酰辅酶A 新途径 体外验证 

分 类 号：Q815[生物学—生物工程]