
MYSUN: Microbial photosYnthesis for SUstainable biosyNtheses
Platform Project - PP4.2
The platform project Microbial photosYnthesis for SUstainable biosyNtheses (MYSUN) aims at tapping oxygenic photosynthetic reactions of microorganisms for the development of a sustainable bioeconomy. A major focus is set on the biological exploitation of oxygenic photosynthesis based on sunlight, H2O, and CO2 as feedstocks. Biotechnological or biohybrid processes are developed, aiming for the production of solar fuels (e.g. H2), biomass or carbon products as well as their further valorization for application purposes. MYSUN covers a holistic research expertise that is relevant to the whole value chain from photosynthesis to product application, including but not limited to molecular microbiology and physiology, biocatalyst engineering, process development, downstream application as well as life cycle assessment and system modelling. With this, MYSUN contributes to the deliverables and milestones of the POF IV Topic 7 "Changing Earth - Sustaining our Future". This PP connects with other PPs (e.g. EBB, CityTech) by sharing common research methodologies or complementing each other on the sustainability value chain, via projects such as light-driven chemical or enzyme catalysis, PV-electrochemical or photoelectrochemical CO2 fixation, H2 utilization and storage, photo-biomass valorisation for chemicals, fuels or agriculture/food supplements, etc.
Based on the research focuses, the contributions of MYSUN participants are integrated into the following work packages (WP):
Working package 1: Tools and strategies to exploit photosynthesis system
The fundamental understanding of how oxygenic photosystems behave under or respond to certain environmental conditions and the capability to rationally engineer the system towards target function are largely constrained. This working package aims to develop effective systems and synthetic tool boxes, which can be utilized for understanding/engineering of metabolic regulation, understanding and tuning the energy and redox flows within photoautotrophic microbes, quantitative understanding of microbial phenotype and behaviour in dependence of environmental conditions and/or stress, etc. Particularly, the research interests include but not limited to:
1. developing molecular biology tools for both soluble and membrane-bound proteins, e.g. CRISPR, CRISPRi, plasmid-based expression system, qPCR, etc;
2. developing metabolic analytic tools for comprehensive phenotyping on population level, e.g. omics’-based techniques from proteomics, metabolomics to fluxomics, etc;
3. developing microfluidic-based tools for quantitative phenotyping on single-cell level, e.g. fluorescence-based microscopy, microscopy-mass spectrometry coupled analysis, etc;
4. developing in-silico approach to predict system behavior and guide rational design, e.g. genome-scale modelling constrained by (omics’) phenotyping data, multi-physics modelling simulating the mass and energy flow, etc.
Working package 2: Light-driven whole-cell biocatalysis
The metabolic potentials of photoautotrophs as industrial biocatalysts are heavily sink-limited. This working package will focus on the exploitation of the highly efficient photosynthetic light reaction, i.e. to tap the photosynthetic electrons in the form of NADPH or ferredoxin as well as O2, to drive biosynthetic processes of energy carriers (e.g. H2, etc) and bulk/fine chemicals. The project partners involved in this working package apply rational biocatalyst engineering in a whole-cell system, with particular interests in e.g. hydrogenase, membrane respiratory proteins, and redox enzymes catalysing carbon-based redox biotransformation and orthogonal pathways, etc. Briefly, the research interests include the following aspects:
1. developing oxygen-tolerant hydrogenase for long-term efficient hydrogen formation;
2. engineering membrane redox and transportation proteins to improve the utilization efficiency of photosynthetic electrons to external electron sink;
3. engineering and constructing redox enzymes or enzyme cascades for efficient biotransformation purposes.
Working package 3: Novel Light-driven bioprocess concepts and technology
Photobiotechnology is driven but also constrained by the light energy binding to surface area. The overall aim of this working package is thus to develop a novel photobioreactor and process concept to maximize the light-use efficiency by optimizing the interface mass and energy fluxes. Research methodologies applied in this working package includes wet-lab bioreactor design and SOPs, in silico process modelling, and system performance evaluation using e.g. life-cycle analysis and techno-economic assessments. Briefly, the specific aims of this working packages are:
1. developing high performance, high cell density and productive photoautotroph biofilm bioreactor for biosynthesis purpose, by understanding and tuning the biofilm architecture and kinetics;
2. developing novel reactor configuration to maximize the sunlight usage, e.g. combining photoactive materials and oxygenic photoautotroph for broad sunlight spectrum utilization, etc;
3. developing optimum process concept by identifying the process window, footprints and practical feasibility using life-cycle analysis and techno-economic assessments, and evaluating the contribution to the (regional) value creation chains.