Prof. Dr. Vitor A.P. Martins dos Santos, Systems and Synthetic Biology, Wageningen University Germany
Monday 27th January 2014, 4.00 p.m., Marlowe Lecture Theatre 1
I will report on the construction of a genome-streamlined bacterium cell endowed with assembled genetic circuits for the production of high added-value aromatics and bioplastics. We developed and validated experimentally a genome-scale, model framework of the metabolism and transport of the biocatalytic chassis, Pseudomonas putida. Predictions pin-pointed interventions that, once implemented in-vivo through combinations of mutants and feeding strategies, enabled re-programming of carbon metabolism for a stark increase in the production of high-value precursors of bioplastics and fine-chemicals. To simplify and stabilize the chassis, we streamlined the 6-megabase genome through a newly developed excision method based on the combination of customized mini-transposons and the FLP-FRT site-specific recombination system. After 4 cycles, we shed 8% of the genome, thereby simplifying cellular wiring with no negative impact on the fitness. Genome-wide analyses of the streamlined chassis – through combined mathematical modelling and experiments – yielded new insights into the metabolism and regulation of this industrial bacterium. In parallel, we developed and experimentally validated a detailed dynamic model of the circuit coded by the pWW0 plasmid (a plug-and-play circuit for the biotransformation of aromatics). The model revealed that the architecture of the key regulatory node of the promoter system Ps/Pr can discriminate between alternative and competing carbon sources, which is of utmost relevance for biocatalyis of aromatic-derived fine chemicals. The study of the interplay between the biocatalytic circuit and the metabolic wiring of the chassis revealed unexpected mechanisms that control the expression of the “plugged-in” circuit. This workflow generated a streamlined bacterial factory, devoid of unnecessary gene complements and undesired cross-talk, thereby enabling a higher degree of control and, hence re-programming, by plugging-and-playing at will.
Vítor Martins dos Santos holds the Chair for Systems and Synthetic Biology at the Wageningen University, The Netherlands, is the Director of the Wageningen Centre for Systems Biology and President of the Dutch Society of Biotechnology. He received a doctorate on environmental bioprocess engineering at Wageningen University. He did a post-doc in the Dept. of Molecular Biology of the Spanish Research Council (CSIC) in Granada, Spain and moved subsequently to the German National Centre for Biotechnology where he built the Systems and Synthetic Biology research group.
He has coordinated and participated in numerous national and international projects in Systems and Synthetic Biology and has been involved in advising science and governance policies, and has carried out intense research in the field. A major thrust of his research is the streamlining of microbial chassis and (computer-assisted) re-programming of cellular behaviour for medical, industrial and environmental applications.