GreenRubber - Sustainable Production of Natural Rubber Using Yeast

Project Information

GreenRubber

Grant agreement ID: 101067117

DOI

10.3030/101067117

Project terminated on 26 November 2024

EC signature date 12 July 2022

Start date 1 January 2023

End date 31 December 2024

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 230 774,40

Coordinated by

KOBENHAVNS UNIVERSITET
Denmark

Periodic Reporting for period 1 - GreenRubber (GreenRubber - Sustainable Production of Natural Rubber Using Yeast)

Reporting period: 2023-01-01 to 2024-12-31

Summary of the context and overall objectives of the project

Natural rubber is a crucial material used in over 50,000 products, from car tires to medical devices, due to its durability, elasticity, and insulation properties. The global demand for natural rubber is increasing, especially in fast-developing Asian countries. However, all commercial natural rubber is currently sourced from rubber trees, mainly grown in South-East Asia, which makes the supply vulnerable to disease, climate change, and weather disruptions. Additionally, the supply chain for rubber contributes to high carbon emissions and geopolitical risks.

In my original plan, I had three main goals to produce natural rubber using yeast:
1. Find the missing components needed for rubber production by experimenting with a plant called Nicotiana benthamiana.
2. Modify yeast cells to produce many small structures called lipid bodies (LBs). These LBs would act like rubber particles, providing a space for rubber to be made and stored inside the yeast.
3. Recreate the natural rubber production process in yeast and fine-tune it to make high-quality rubber.

However, I didn’t pursue the third goal because the first two didn’t yield the expected results. Instead, we shifted the project’s focus to a new direction: creating a yeast cell factory to produce materials for rubber alternatives. As part of this new approach, we added a new goal:

2’. Find the most effective enzyme (myrcene synthase) in yeast and show that yeast can produce myrcene at a rate of half a gram per liter in the lab.

This new goal was successfully achieved.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In my original project, I aimed to find the missing pieces needed for natural rubber production using lettuce as a model plant. Here’s what I did:

1. Tested known rubber-making components in tobacco plants, lettuce, and yeast to see if they could work in these systems.
2. Tried providing the building blocks for rubber production in tobacco plants through a technique called infiltration.
3. Identified new genes potentially involved in rubber production by analyzing published data from lettuce.
4. Examined gene activity in wild lettuce, which produces more natural rubber than regular lettuce.

To prepare yeast cells for rubber production, I:
1. Boosted the production of lipid droplets, small structures in yeast cells that could serve as “factories” for making rubber.
2. Tweaked the yeast's growth conditions to reduce stress and improve their efficiency.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The failure to produce natural rubber in the original project led me to hypothesize that the process is tightly controlled by the balance between two key building blocks. Their ratio might play a critical role in determining whether rubber can be successfully made. Additionally, when certain proteins were added, the amount of natural rubber increased, suggesting that these proteins might not be essential but are helpful for boosting rubber production.

The success of the new project provides a solid foundation for further improvements. With more optimization, it could eventually enable large-scale production of these alternative building blocks for natural rubber.

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