Biology subjects

Liu, W.-Q.

Publications and source records attributed to Liu, W.-Q..

3 recordsLinked to original sources

bioRxiv2022

Engineering Escherichia coli to utilize erythritol as sole carbon source

Erythritol, one of the natural sugar alcohols, is widely used as a sugar substitute sweetener in food industries. Human themselves are not able to catabolize erythritol and their gut microbes lack related catabolic pathways either to metabolize erythritol. Here, we engineer Escherichia coli to utilize erythritol as sole carbon source aiming for defined applications. First, we isolate the erythritol metabolic gene cluster and experimentally characterize the erythritol-binding transcriptional repressor and its DNA-binding site. Transcriptome analysis suggests that carbohydrate metabolism-related genes in the engineered E. coli are overall upregulated, which then guides the selection of four genes for overexpression that notably enhances cell growth. Finally, engineered E. coli strains can be used as a living detector to distinguish erythritol-containing soda soft drinks and can grow in the simulated intestinal fluid supplemented with erythritol. We expect our work will inspire the engineering of more hosts to respond and utilize erythritol for broad applications in metabolic engineering, synthetic biology, and biomedical engineering.

synthetic biology↗

bioRxiv2021

SYMBIOSIS: Synthetic Manipulable Biobricks via Orthogonal Serine Integrase Systems

Serine integrases are emerging as one of the most powerful biological tools for synthetic biology. They have been widely used across genome engineering and genetic circuit design. However, developing serine integrase-based tools for directly/precisely manipulating synthetic biobricks is still missing. Here, we report SYMBIOSIS, a versatile method that can robustly manipulate DNA parts in vivo and in vitro. First, we proposed a "Keys match Locks" model to demonstrate that three orthogonal serine integrases are able to irreversibly and stably switch on seven synthetic biobricks with high accuracy in vivo. Then, we demonstrated that purified integrases can facilitate the assembly of "Donor" and "Acceptor" plasmids in vitro to construct composite plasmids. Finally, we used SYMBIOSIS to assemble different chromoprotein genes and create novel colored Escherichia coli. We anticipate that our SYMBIOSIS strategy will accelerate synthetic biobricks manipulation, genetic circuit design, and multiple plasmids assembly for synthetic biology with broad potential applications.

synthetic biology↗

bioRxiv2020

Cell-free protein synthesis enables one-pot cascade biotransformation in an aqueous-organic biphasic system

Biocatalytic cascade reactions have become increasingly important and useful for chemical synthesis. However, biocatalysts are often incompatible with organic solvents, which prohibits many cascade reactions involving nonpolar substrates. In this work, we used cell-free protein synthesis (CFPS) to express enzymes in an aqueous-organic biphasic system for the construction of an artificial enzymatic pathway. CFPS-expressed enzymes without purification performed efficiently to convert styrene (below 20 mM) to (S)-1-phenyl-1,2-ethanediol (two steps in one pot) with 100% conversion. In addition, our CFPS system showed great tolerance to different organic solvents and, importantly, the entire biocatalytic system can be consistently scaled up without reduction of the substrate conversion rate. We therefore anticipate that our cell-free approach will make possible cost-effective, high-yielding synthesis of valuable chemicals.

synthetic biology↗