The new revolution of eco-friendly materials for paper container manufacturing--- CCU Taiwan iGEM team takes the gold medal in 2018 International Genetically Engineered Machine Competition (iGEM )

Published on Nov 14 2018

Taiwanese people love the hand-made tea-drinks from the tea houses/stores, so that it once made the numbers of customized paper cups consumed to its highest record of 1.07 billion, in a particular year. However, these paper cups, same as the lunch boxes, which all have been laminated with an indecomposable plastic film inside, making them difficult to be recycled. And this has created an environmental problem of great urgency and needs to be dealt with. Consequently, an interdisciplinary research team was formed by16 students from National Chung Cheng University (CCU) trying to work out a solution. They use genetic engineering technology to produce a new "lignin-like" material (LIGGREEN) with waterproof, heat-resistant and decomposable properties, it is expected to replace the petrochemical materials such as polypropylene and polyethylene currently used for paper cup lamination. The CCU team later entered the International Genetically Engineered Machine Competition (iGEM ) held in the U.S. with its unique product. At the end of the event, the design and innovative applications earned the recognition and was highly praised by judges with a gold medal.

" Though our government has enforced the policy on the restriction of disposable plastic products, that does not solve the fundamental problem. A lot of people still, nearly always, order one tea-drink every day. We want to help reduce the plastic waste from the paper containers accumulating in the nature." says Ho-Chun (Jim) Ku (顧賀鈞), a member of the CCU iGEM team. Most people believe that paper cups or lunch boxes can be 100% recycled. But in fact, the waterproof, heat resistant and naturally indecomposable film made of thin wax or plastic inside the paper cups, which will cost a great deal to separate from the paper, has made the cup difficult to be recycled.

Team member Yuan-Chi (Chichi)Tung (董元琪) also addresses that due to the high technology and the cost involved in the separation process, the paper cup recycling problem has not yet been dealt with properly in the community. At present, except one company, no one is able and willing to do that sort of business in Taiwan. Therefore, some dealers of recycled goods refuse to take those kind of paper products since it will be hard to find the buyers. And worse, that situation generates a mis-understanding making people assume the paper cups and lunch boxes are no longer recyclable, resulting in a poor recycle rate of merely 25%. As a lot of paper containers are not going to be recycled, they end up to the dump. The problem is, these plastic films will take more than a hundred years to decompose if they are disposed of in a landfill; or if they are burned in a wasted incineration plant, harmful gases, such as dioxin, will be given off; either way can easily have significantly negative impacts on our environment.

"To make waterproof, high-heat resistant and 100% decomposable products to replace the petrochemical materials currently used for paper cup lamination, we believe the synthetic lignin is the answer for it." Another team member Chiao (Joe) Hsiao (蕭喬) explains that lignin is found in the xylem of plants and is a natural material that can be decomposed by fungi. The CCU iGEM team spent a lot of time reading foreign papers on synthetic lignin, noting that the tree species Picea abies and Pinus taeda are some of the most common plants studied for lignin synthesis. Accordingly, the team selects peroxidase genes from P. abies and laccase gene from P. taeda, which are respectively responsible in producing the enzymes, peroxidase and laccase, then transforms those genes into Pichia pastoris. Once the enzymes are produced by the modified P. pastoris, they are used to react with the monolignols to make a lignin-like material.

Based on the scientific findings, Chiao Hsiao also points out that, the lignin-like materials developed by the team are expected to be used as a waterproof coating for the inner layer of paper containers in the future. The new materials can also be completely decomposed by the bacteria called Bacillus subtilis, and the methane produced largely by such decomposing process tends to be used as an alternative fuel or for power generating purposes.

The International Genetically Engineered Machine Competition is a globally high-level competition on synthetic biology, sponsored by the Massachusetts Institute of Technology in the U.S. Using synthetic biology to solve common life problems is the must-be criteria to enter the competition. The "CCU Taiwan" team is led by Associate Professor, Cheng-I Lee, of the Department of Biomedical Sciences. The team consists of 16 students from the Colleges of Science, Engineering, Social Sciences and Management. The instructors for the team come across different disciplines, including the Department of Biomedical Sciences, the Department of Chemical Engineering, the institute of Linguistics, the Department of Electrical Engineering, the Department of Mechanical Engineering and the Department of Computer Science and Information Engineering.

In the more-than-one-year-long research and developing process, the team had not only undergone a solid basic experiment training in biology, but also took part in other activities, such as going for the beach cleanups and visiting the resource recycling plants, to understand the impacts derived from plastic products onto the environment; as well as the intensive conducts of experimental work during the summer vacation, sometimes the team members even had to sleep over in the study room waiting for results. It was a tough experience for all participants. However, the research efforts were finally paid off in the iGEM event. What CCU team had achieved was recognized and favored by the judges, winning the gold medal out of 340 competing counterparts globally. The team’s product, LIGGREEN, was also nominated for the Best Product Design and Best New Application Project in the competition.

CCU announces that, currently, the team is working hard on the relevant follow-up experiments in order to optimize the products, and will soon be able to apply for patents for its research accomplishment. The university hopes to partner with other industrial entrepreneurs in the future to open up a channel for eco-friendly materials in the field of paper container manufacturing.