Production of adipic acid by the native-occurring pathway in Thermobifida fusca B6
作者单位：江南大学粮食发酵工艺与技术国家工程实验室 The Key Laboratory of Industrial BiotechnologyMinistry of EducationJiangnan University National Engineering Laboratory for Cereal Fermentation Technology (NELCF)Jiangnan University
会议名称：《中国生物工程学会第六次全国会员代表大会暨第九届学术年会》
会议日期：2015年
学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术]
关 键 词：adipic acid T.fusca B6 reverse adipate degradation pathway 5-Carboxy-2-pentenoyl-CoA reductase corncob
摘 要：Aims:To identify the native-occurring adipate pathway in a previously engineered Thermobifida fusca B6 strain and optimize the adipic acid production of this strain on glucose and corncob.Methods and Results:The native-occurring adipate pathway in T.fusca B6 was identified to be the reverse adipate degradation pathway,including 5 steps:β-ketothiolase(Tfu875),3-hydroxyacyl-CoA dehydrogenase(Tfu399),3-hydroxyadipyl-CoA dehydrogenase(Tfu067),5-Carboxy-2-pentenoyl-CoA reductase(Tfu647) and succinyl-CoA synthetase(Tfu576,Tfu577).The cell lysates of T.fusca wild-type strain with the addition of the Tfu647 protein produced trace adipic acid,while no adipic acid was produced in the absence of this protein.The above results prove that the low expression of Tfu647 in the WT strain was the reason why it didn’t produce any adipic acid.We then demonstrated that in T.fusca B6,the maximal titer of adipic acid on 50 g/L glucose was 2.23 g/L with 0.045 g/g-glucose yield and 0.22 g/L adipic acid was produced from 19.38 g/L milled corncob.Conclusions:The reverse adipate degradation pathway was found to be responsible for the adipate synthesis in T.fusca B6 and Tfu647 was the regulatory node on this pathway.Significance and Impact of Study:T.fusca B6 was the first reported microorganism using its native-occurring pathway to accumulate adipic acid.It had the highest reported yield and titer of adipic acid so far.