Bator Isabel, Wittgens Andreas, Rosenau Frank, Tiso Till, Blank Lars M
iAMB - Institute of Applied Microbiology, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
Institute for Pharmaceutical Biotechnology, Ulm-University, Ulm, Germany.
Front Bioeng Biotechnol. 2020 Jan 17;7:480. doi: 10.3389/fbioe.2019.00480. eCollection 2019.
KT2440 is a well-established chassis in industrial biotechnology. To increase the substrate spectrum, we implemented three alternative xylose utilization pathways, namely the Isomerase, Weimberg, and Dahms pathways. The synthetic operons contain genes from and . For isolating the Dahms pathway in KT2440 two genes (PP_2836 and PP_4283), encoding an endogenous enzyme of the Weimberg pathway and a regulator for glycolaldehyde degradation, were deleted. Before and after adaptive laboratory evolution, these strains were characterized in terms of growth and synthesis of mono-rhamnolipids and pyocyanin. The engineered strain using the Weimberg pathway reached the highest maximal growth rate of 0.30 h. After adaptive laboratory evolution the lag phase was reduced significantly. The highest titers of 720 mg L mono-rhamnolipids and 30 mg L pyocyanin were reached by the evolved strain using the Weimberg or an engineered strain using the Isomerase pathway, respectively. The different stoichiometries of the three xylose utilization pathways may allow engineering of tailored chassis for valuable bioproduct synthesis.
KT2440是工业生物技术中一种成熟的底盘细胞。为了扩大底物谱，我们引入了三种替代的木糖利用途径，即异构酶途径、温伯格途径和达姆斯途径。这些合成操纵子包含来自[具体来源未提及]和[具体来源未提及]的基因。为了在KT2440中分离出达姆斯途径，删除了两个基因（PP_2836和PP_4283），它们分别编码温伯格途径的一种内源酶和乙醇醛降解的一个调节因子。在适应性实验室进化前后，对这些菌株的生长以及单鼠李糖脂和绿脓菌素的合成进行了表征。使用温伯格途径的工程菌株达到了最高的最大生长速率0.30 h⁻¹。经过适应性实验室进化后，延迟期显著缩短。使用温伯格途径的进化菌株和使用异构酶途径的工程菌株分别达到了最高产量，单鼠李糖脂为720 mg L⁻¹，绿脓菌素为30 mg L⁻¹。三种木糖利用途径的不同化学计量学可能允许设计出用于合成有价值生物产品的定制底盘细胞。
