Kirin Holdings Company – Started joint research on PET, degrading enzymes for sustainable recycling

TOKYO – Kirin Holdings Company, Limited (Kirin Holdings), Shizuoka Universityand National Institutes of Natural Sciences (NINS) will initiate joint research to establish PET*1 enzymatic recycling technology in January 2022. It is hoped that a new method of chemical recycling using enzymes to break down plastic at the molecular level will result in more efficient, sustainable and environmentally friendly recycling.

Fund: Chemical recycling

With the strong awareness of sustainability around the world, the recycling of PET plastic in particular has gained attention, as many kinds of products containing PET can be found very easily in our daily lives. In particular, there is a shared urgency regarding the creation of a sustainable PET recycling system in which container and packaging resources are recycled. Consequently, interest has grown in chemical recycling technology as a solution to this problem.

In chemical recycling, waste PET bottles are sorted, crushed and washed to remove dirt and foreign substances, then subjected to chemical decomposition to break them down and refine them into raw materials, which are then synthesized back into PET. . Currently, in the chemical recycling technology decomposition process, metal catalysts are used, and the heat treatment is carried out at high temperatures of about 300 degrees Celsius. On the other hand, the enzymatic decomposition method is attracting attention as a new recycling process, which uses enzymes instead of metals as catalysts in the degradation process.

The enzymatic degradation method

The enzymatic degradation method involves using heat-resistant PET degrading enzymes to break down PET to the molecular level of monomer. This means that PET plastic can be broken down into microscopic pieces, allowing for purer recycled PET plastic (because it is much easier to separate foreign substances from the plastic). Additionally, by using enzymes as catalysts, the decomposition process can be carried out at relatively low temperatures around 70 degrees Celsius, reducing the environmental impact at the same time.

Kirin Holdings has been conducting research and development on PET2 – a thermostable enzyme that degrades PET – since 2019, aiming to use it as a basis to establish a kind of PET recycling by the enzymatic degradation method. This happened during the research of recycling technologies that use fermentation technologies Kirin Holdings has already grown for decades.

Moreover, in July 2021 Shizuoka University and NINS announced the results of a study in which a modified PET2 enzyme significantly improved its thermal stability and ability to degrade PET.

Kirin Holdings, Shizuoka University and NINS believe that by combining their respective knowledge, they will be able to accelerate research and development for the practical use of PET degrading enzymes and aim to establish PET degradation technology using the method in the future. enzymatic degradation.

2 Shizuoka University press release from July 1, 2021Improving the thermal stability and activity of plastic degrading enzymes, and elucidating the structural basis of improved thermal stability and the mechanism of increased activity. https://www.shizuoka.ac.jp/news/detail.html?CN=7325, Japanese)

Research overview

Although there are several enzymes capable of degrading PET – one of the most commonly used plastics in the world – only a few of them have been put into practice because enzymes have a low heat tolerance and a low degradation activity under high temperature conditions. In this joint research, the objective is to obtain a thermostable PET degradation enzyme with improved heat tolerance and degradation activity by modifying PET2 – one of the thermostable PET degradation enzymes – by combining the knowledge and technologies held by the three parties.

Moreover, based on the mechanism of PET degradation activity revealed by X-ray crystallography and single molecule observation, Shizuoka University and NINS will create a PET-degrading enzyme that can withstand practical use using the three parties’ respective enzyme modification and screening technologies.

Expected results

The development of PET degrading enzymes with high thermal stability and degrading activity will reduce the amount of enzymes required for PET degradation, thereby reducing the cost of PET recycling. The enzymatic degradation method can also reduce the thermal energy needed to degrade PET under mild conditions, thereby reducing environmental impact.

the Kirin Group Container and Packaging Initiatives

Kirin Holdings aims to achieve PET recycling technology using the environment-friendly enzymatic degradation method through this joint research to achieve the goal of 50% of all PET plastic used in Japan to be recycled by 2027 as indicated in the Kirin group Plastic Policy.

Before that, the Kirin Group working on a joint project with Mitsubishi Chemical Corporation establish a chemical recycling technology that will allow a continuous “recycling cycle” from PET bottles to other PET products and back to PET bottles.

On Kirin Holdings

Kirin Holdings Company, Limited is an international company that operates in food and beverage business (food and beverage business), pharmaceutical business (pharmacy business) and health science business (science business of health), both in Japan and across the world.

Kirin Holdings can trace its roots back to Japan Brewery which was established in 1885. Japan Brewery became Kirin Brewery in 1907. Since then, the company has expanded its business with fermentation and biotechnology as core technologies, and entered the pharmaceutical sector in the 1980s, all of which continue to be global growth centers. In 2007, Kirin Holdings was established as a pure holding company and is currently focused on strengthening its field of health sciences.

As part of the Kirin Group Vision 2027 (KV 2027), a long-term management plan launched in 2019, the Kirin Group aims to become “a global leader in CSV*, creating value in our world, from food and beverage to pharmaceuticals”. In the future, the Kirin Group will continue to leverage its strengths to create both social and economic value through its operations, with the aim of achieving sustainable growth in enterprise value.