Team:KU LEUVEN/Description

Vision

Global resource depletion poses a threat to our society, creating a strong demand for durable and sustainable solutions within the industry. Meeting this challenge requires a thorough rethinking of production chain steps regarding the sustainability of resources and the possibility to substitute current petrol-based supply-chains with pathways of renewable resources. Our team project, OCYANO, explores using cyanobacteria as a means of photosynthetic biomanufacturing.

With applications covering a great many areas like the food, textile, paper, and animal feed industries [1][2], the global industrial enzyme market is on a continuous rise. Driven by a growing need for sustainable solutions, the enzyme manufacturing market is projected to reach USD 7.0 billion by 2023 [3].

Currently, enzyme production has relied mostly on heterotrophic expression systems such as E. coli or yeast that require substantial amounts of growth media. Direct utilization of photons by photoautotrophic enzyme production allows for the production of these catalysts requiring little more than carbon dioxide, light, and water. Thus, utilizing cyanobacteria provides a powerful platform for the production of commonly used industrial enzymes, such as cellulases and galactosidases.

Inspired by The Sustainable Development Goals, a collection of 17 goals set by the UN towards a more sustainable future by 2030, the team has decided to focus their efforts on Goal 12: Responsible Consumption & Production: “Doing more and better with less.” [4]. As a team, we decided to explore two approaches towards sustainable and large-scale production of enzymes with applications in the food, textile, paper, and animal feed industries.

In the first approach, we would like to employ a recently discovered freshwater cyanobacterial strain as an efficient cell factory for mass production. This strain has been observed to show rapid autotrophic growth with rates comparable to commonly used heterotrophic industrial hosts such as E. coli and yeast [5]. Moreover, photoautotrophic enzyme production has the potential to reduce the demand for carbon sources as growth media. Consequently, this leads to considerable savings in fossil fuel resources needed for the production of these media.

In the second approach, we would like to exploit marine cyanobacteria, present in vast numbers worldwide [6], as a resource for mass production. We are planning to use genetically engineered phages as tools that convert the biomass from isolated wild-type marine cyanobacteria into enzymes. By utilizing the sea as a resource, we are developing an alternative and more sustainable way of producing enzymes. Cyanobacterial cell lysis for subsequent enzyme harvesting is a major bottleneck in the industrialization of cyanobacteria [7]. By using the phage lytic cycle as a way of circumventing this bottleneck, we hope to reduce the cost associated with the use of these bacteria significantly.

In a world of increased urgency for durable and sustainable solutions, we, the iGEM team of KU Leuven, decided to focus our efforts on solar-powered micro-organisms. Striving for a world with improved environmental sustainability, our team is bundling forces this summer to solve the issue of sustainable production patterns through cyanobacteria.

References

1. M. Bartsch et al., “Photosynthetic production of enantioselective biocatalysts,” Microb. Cell Fact., vol. 14, no. 1, p. 53, Dec. 2015.
2. B. dos S. A. F. Brasil, F. G. de Siqueira, T. F. C. Salum, C. M. Zanette, and M. R. Spier, “Microalgae and cyanobacteria as enzyme biofactories,” Algal Res., vol. 25, pp. 76–89, Jul. 2017.
3. “Global Markets for Enzymes in Industrial Applications.” [Online]. Available: https://www.bccresearch.com/market-research/biotechnology/global-markets-for-enzymes-in-industrial-applications.html. [Accessed: 29-Jul-2019]
4. “About the Sustainable Development Goals - United Nations Sustainable Development.” [Online]. Available: https://www.un.org/sustainabledevelopment/sustainable-development-goals/. [Accessed: 29-Jul-2019].
5. J. Yu et al., “Synechococcus elongatus UTEX 2973, a fast growing cyanobacterial chassis for biosynthesis using light and CO2,” Sci. Rep., vol. 5, no. 1, p. 8132, Jul. 2015.
6. P. Flombaum et al., “Present and future global distributions of the marine Cyanobacteria Prochlorococcus and Synechococcus,” Proc. Natl. Acad. Sci. U. S. A., vol. 110, no. 24, pp. 9824–9829, Jun. 2013.
7. K. K. Mehta, N. H. Evitt, and J. R. Swartz, “Chemical lysis of cyanobacteria,” J. Biol. Eng., vol. 9, no. 1, p. 10, Dec. 2015.