Title: Microbes-enabled sustainable biomanufacturing of food, chemical and medicine
Abstract:
In the natural food chain, plants/algae are the producers, animals are the consumer and microbes are the decomposer. A recent technological breakthrough in synthetic biology has broadened the role of microbes. Microbial cells have now become a great “producer” or “factory” to synthesize various products in food, agriculture, medicine and chemicals from plant-based feedstocks (e.g., sugars) and even directly from CO2. Microbial synthesis is transforming the products and processes in manufacturing that are substantially more sustainable and friendly to the environment and society, to realize a zero-waste circular economy. The versatile capability of microbes can overcome the knotty supply chain issue by diversifying the type of feedstocks from lignocellulose to wastes and to CO2. Here, in my team, we have been focusing on using CO2-based next-generation feedstocks to produce food ingredients (single-cell protein, polyunsaturated lipids, e.g., omega-3) and flavor, fragrance, and nutraceutical molecules. Today, we can produce >50 g/L of proteins in bioreactors with a productivity of ~2.5 g/L/h using red yeasts. Besides food ingredients, we target isoprenoids, or terpenoids, which constitute the largest group of natural products (>95,000). The structural diversity of terpenoids contributes to wide applications ranging from pharmaceuticals (e.g., artemisinin), nutraceuticals (e.g., astaxanthin), flavors and fragrances (e.g., linalool), polymer molecules (e.g., isoprene) and biofuels (e.g., farnesene). Unlike plant terpenes that are well studied, fungal terpenes and their synthases remain largely untapped. My team has developed an integrated platform for the discovery of novel fungal terpene synthases (TPSs). Coupling bioinformatics and experiments, we have successfully predicted several unique clusters of putative isofunctional TPSs (e.g., protoilludene, viridiflorol) and identified a highly active and specific linalool synthase. Also, we developed a systematic optimization method, a multidimensional heuristic process (MHP), to efficiently synthesize these molecules in Escherichia coli. With MHP and enzyme engineering, we are able to produce >10 high-value molecules at near theoretic yields and high titers including sesquiterpenes (16 g/L nerolidol, 26 g/L viridiflorol and 30 g/L amorphadiene), monoterpenes (linalool, > 9 g/L geranyl acetate), carotenoids (e.g., astaxanthin, phytoene), apocarotenoids (α-ionone with a price of >5,000 €/kg, irone with a price >20,000 €/kg), etc. Currently, we are working on connecting the biosynthetic pathway of acetate and ethanol to acetyl-CoA with terpene biosynthetic pathways.
Audience take away notes:
- How synthetic biology can assist the transition from fossil oil to renewable biomass.
- Our demonstration that from lab to industry in using microbes to produce food, feed and medicine
- Learn about state-of-art synthetic biology.
- Learn how synthetic biology can help with circular economy and sustainable future.
- The research is highly multi-disciplinary, can integrate with chemistry, material and chemical engineering, biomedical research.
- It provides a practical solution for sustainable biomanufacturing in chemicals, food and medicine.
- We will apply biotechnology for sustainable biomanufacturing from CO2 directly to cope with global warming, we aim to develop carbon negative/neutral biotechnology.
