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Research

Biological systems - including the simplest cells - exhibit a broad range of functions to thrive in their environment. Research in the Imperial College Centre for Synthetic Biology is focused on the possibility of engineering the underlying biochemical processes to solve many of the challenges facing society, from healthcare to sustainable energy. In particular, we model, analyse, design and build biological and biochemical systems in living cells and/or in cell extracts, both exploring and enhancing the engineering potential of biology.

As part of our research we develop novel methods to accelerate the celebrated Design-Build-Test-Learn synthetic biology cycle. As such research in the Centre for Synthetic Biology highly multi- and interdisciplinary covering computational modelling and machine learning approaches; automated platform development and genetic circuit engineering ; multi-cellular and multi-organismal interactions, including gene drive and genome engineering; metabolic engineering; in vitro/cell-free synthetic biology; engineered phages and directed evolution; and biomimetics, biomaterials and biological engineering.

Publications

Citation

BibTex format

@article{Wu:2018:10.1016/j.ymben.2018.08.012,
author = {Wu, Y and Chen, T and Liu, Y and Lv, X and Li, J and Du, G and Ledesma, Amaro R and Liu, L},
doi = {10.1016/j.ymben.2018.08.012},
journal = {Metabolic Engineering},
pages = {232--241},
title = {CRISPRi allows optimal temporal control of N-acetylglucosamine bioproduction by a dynamic coordination of glucose and xylose metabolism in Bacillus subtilis},
url = {http://dx.doi.org/10.1016/j.ymben.2018.08.012},
volume = {49},
year = {2018}
}

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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Glucose and xylose are the two most abundant sugars in renewable lignocellulose sources; however, typically they cannot be simultaneously utilized due to carbon catabolite repression. N-acetylglucosamine (GlcNAc) is a typical nutraceutical and has many applications in the field of healthcare. Here, we have developed a gene repressor system based on xylose-induced CRISPR interference (CRISPRi) in Bacillus subtilis, aimed at downregulating the expression of three genes (zwf, pfkA, glmM) that control the major competing reactions of GlcNAc synthesis (pentose phosphate pathway (HMP), glycolysis, and peptidoglycan synthesis pathway (PSP)), with the potential to relieve glucose repression and allow the co-utilization of both glucose and xylose. Simultaneous repression of these three genes by CRISPRi improved GlcNAc titer by 13.2% to 17.4±0.47g/L, with the GlcNAc yield on glucose and xylose showing an 84.1% improvement, reaching 0.42±0.036g/g. In order to further engineer the synergetic utilization of glucose and xylose, a combinatorial approach was developed based on 27 arrays containing sgRNAs with different repression capacities targeting the three genes. We further optimized the temporal control of the system and found that when 15g/L xylose was added 6h after inoculation, the most efficient strain, BNX122, synthesized 20.5±0.85g/L GlcNAc with a yield of 0.46±0.010g/g glucose and xylose in shake flask culture. Finally, the GlcNAc titer and productivity in a 3-L fed-batch bioreactor reached 103.1±2.11g/L and 1.17±0.024g/L/h, which were 5.0-fold and 2.7-fold of that in shake flask culture, respectively. Taken together, these findings suggest that a CRISPRi-enabled regulation method provides a simple, efficient, and universal way to promote the synergetic utilization of multiple carbon sources by microbial cell factories.
AU  - Wu,Y
AU  - Chen,T
AU  - Liu,Y
AU  - Lv,X
AU  - Li,J
AU  - Du,G
AU  - Ledesma,Amaro R
AU  - Liu,L
DO  - 10.1016/j.ymben.2018.08.012
EP  - 241
PY  - 2018///
SN  - 1096-7176
SP  - 232
TI  - CRISPRi allows optimal temporal control of N-acetylglucosamine bioproduction by a dynamic coordination of glucose and xylose metabolism in Bacillus subtilis
T2  - Metabolic Engineering
UR  - http://dx.doi.org/10.1016/j.ymben.2018.08.012
UR  - http://hdl.handle.net/10044/1/64072
VL  - 49
ER  -