DePet

Human Practices

While biological or engineered solutions are crucial in solving environmental problems, the social aspect of these solutions should not be overlooked. In addition to experimenting with the PETase enzymes and E. Coli, our team realized that raising awareness about the plastic epidemic to the general public is equally as important in order to be able to garner public support and spread the idea that the biological solutions that we were working on are necessary in order to preserve the world. In order to achieve such goals, we first made sure we had the necessary knowledge about plastic to teach others by interviewing professionals, learning from environmental groups (iCOOP), and having discussions on how to minimize the negative impact of plastic.

Our group interviewed many professionals to gain further depth in our knowledge of the experiment and effects. In total, we had interviewed five people ranging from researchers who conducted very similar experiments as us and people who are very passionate about resolving the plastic epidemic in society today. Overall, our team interviewed a number of experts in the field to gain a better understanding of not only our solution’s strengths, weaknesses, etc. but also other potential issues and ideas that are relevant to our project as well.

“iCOOP (자연드림)”, an environmental group in Korea, informed us about general knowledge on plastic and how current trends were shifting to the worse. By having multiple educational sessions with the volunteer workers, we were able to verify our current understanding of plastic and notice a difference between the explanation of plastic issues written on documents and that of actual experiences of volunteers.

Finally, before we started informing others about this issue, we had frequent discussions with each other about who our target audience will be, what we were planning on sharing with them, and how we were going to deliver that message successfully. After many hours of discussion, we decided to educate the next generation about the increasing dangers of the plastic epidemic and initiate street campaigns for further awareness.

Now that we knew we had verified our knowledge and gained a deeper understanding about plastic, we worked on in-school education about the plastic epidemic to students, collaborated with a tourist center, and initiated street campaigns subjected to the pedestrians on the streets.

The in-school education was conducted on three levels: kindergarten, elementary, and middle school. The educational content focused on the basics of what plastic is and how exactly plastic affects the ecosystem and, eventually, human beings too. We attempted to discuss not only the issue but potential solutions as well. Through our educational presentations to all three age groups, we were able to identify how well the next generation was informed about plastic and its devastating effects, allowing us to further educate them about necessary details that they were lacking. We wished to educate others, very much like us, into understanding the importance of resolving the plastic epidemic. At the end of each presentation, we included a description of the project we are participating in and how it can combat the plastic epidemic, in terms suitable to the audiences we were presenting to.

The public campaigns were held both in our school (SIS) and Chiri National Park. For our school campaign, which was conducted throughout a full week, was composed of holding surveys about the public perception about the plastic epidemic and further educating passing students on the subject. We even distributed eco-friendly items such as corn straws for free. In our public campaign, we interviewed and educated passing people regarding our topic and project at Chiri National Park. Chiri Mountain is a popular wildlife tourist attraction in Korea due to the variety of life forms inhabiting it. In order to reduce plastic waste that may potentially harm the creatures native to the mountain, we collaborated with Chiri Tourist Hotel to prevent tourists from irresponsibly throwing away plastic waste and raise awareness about the plastic epidemic. With the Zero Plastic reward service, a service that allows tourists to save up points by participating in plastic reduction activities and purchase eco-friendly products, we handed out pamphlets containing information about the severeness of current plastic situations and our solution to this epidemic. As such, our team employed a multitude of methods to raise awareness regarding the dangerous effects of plastic and garner support for our project.

Interview

Tajkia Syeed Tofa

Tajkia Syeed Tofa is a researcher working at KTH Royal Institute of Technology whose expertises are Environmental Nanotechnology, Advanced Oxidation Processes, Microplastic, and many more areas. We interviewed her in order to get a better understanding of different potential methods of degrading plastic and how our own solution compares to them.

Professor Tofa started on a project for microplastic identification in 2017 after approaching a group studying microplastic degradation. After researching photodegradation, a new method of degrading microplastic with the use of sunlight, she realized the similarity between its process and photosynthesis. When microplastic or bigger pieces of plastic are exposed to sunlight, light energy is converted into chemical energy, weakening the chemical bonds in plastic. This allows the plastic waste to degrade a lot faster compared to when they are left alone. Tofa also introduced another method called photocatalytic degradation: providing an environment for microplastic to break down even faster. She clearly pointed out that these processes can help accelerate the breaking down of chemical bonds. The “reduction environment”, she explained, was created by utilizing redox reactions; Hydroxyl, chlorine, or ozone is generally used, but she specifically chose zinc oxide for her project.

For the last few years, she focused on zinc oxidation, which she believes is one of the most effective degradation methods due to the advantages zinc has over other elements. Compared to others, zinc is less harmful to the environment including marine animals. However, she did concede that there should be more progress made for this subject, and also noted the possible development of technology called NANOBIC Base Device that may be able to help her group control degradation of plastic. Her biggest concern for microplastic is the difficulty of detecting and trapping them to be degraded. Currently, she is working on extracting microplastic from soil with her students. She added that another problem is lack of awareness on microplastic.

Finally, Professor Tofa stated that the most important action that everyone can take in order to prevent and slow the plastic epidemic is to remove plastic from daily lives. With everyone contributing, the world will surely be a better place with less plastic waste. The next step, she stated, was to raise awareness and educate those who do not know about the severity of this issue. It is critical for people to fully understand that producing plastic waste will eventually harm humanity in a variety of ways, ranging from environmental damage to physical consumption.

The interview with Tofa opened new doors for our igem project. Before we could come up with a solid answer to the social issue of plastic, her interview provided us with several alternative ways of degrading plastic. Her information was very helpful since she gave us opportunities to develop valuable insights into different kinds of scientific processes including photodegradation and photocatalytic degradation. Although we ended up implementing different designs and ideas for our project, we greatly appreciate her sincere interview and her genuine interest for the subject of degrading plastic.

Dr. Gert Weber

Dr. Gert Weber is a researcher at Helmholtz-Zentrum Berlin and studies mostly about molecular cloning and gene expression. During his research, he met Uwe Bornscheuer, who we also interviewed, and decided that it would be great to make more structures of plastic degrading enzymes onto their ligands for better expression. Through his interview, we learned about how researchers figure out the structure of a protein to change its expression and how plastic degradation can become a more sustainable business in the future. Dr. Weber’s interview was crucial for our project as our project also involves genetic modification (of E.Coli) and future uses for our product. His expertise in this subject helped us get a better understanding of why our idea was one that is necessary for the future.

First, when asked about how scientists can create a change in gene expression, Dr. Weber explained to us the history of gene modification. He stated that to find which specific amino acid to change, researchers from the 1930s took x-rays to shoot at salt crystals, got a pattern that they could record, which let them calculate the distances of atoms inside crystals. Yet, they were not able to implement the same method for proteins due to their uncrystallizable nature (proteins need to be surrounded by water or else their structure will collapse). Thus, the researchers resorted to crystallizing proteins in their liquid phase, which will act as an amplifier after the x-ray process, and the little dots that result will show the enzyme structure. After modifying the enzyme, the researchers compared the structure of it with and without the ligand to see just how the enzyme binds to a substrate. Lastly, with biotechnology, they were able to observe which amino acid goes where, and were able to measure the activity of the enzyme, implementing changes here and there.

Yet, Dr. Weber grimly stated that the general activity of the enzyme is still too low to build a plastic-degrading factory. Thus, the most substantial goal at the moment is to improve the activity of the enzyme. In the present, what we can do is explore the biodegradability of two different plastic types. One is PET, made mostly of polypropylene and polyethylene, and the other is olefin, those made only of hydrocarbon chains. Olefins are very hard to break down with enzymes; some will degrade it, but the substances will cause a carbon release and will be released into the environment. On the other hand, polypropylene and polyethylene, which make up only 20% of the plastic usage, are bio-friendly, with some even being made out of biomass.

However, it is not easy to create a “green” society. With consumers expecting the best quality plastic for every product, recycled plastics do not match the quality of a new product. Furthermore, many crude oil factory jobs are on the line if the society changes for the environmental cause; thus, no government official would ever create laws like such for their own political survival. Other natural powers, like solar or hydropower, still need some carbon to produce these, but it even does not degrade a necessary amount of PET.

There is one solution that Dr. Weber encourages. Polymers can resynthesize a product without it suffering from product downgrade. Enzymes will degrade, too, but the energy and carbon needed to synthesize it will be able to be kept in a loop. At the same time, people will need to be forced to collect their waste and recycle, or no circular economy will ever work.

Dr. Uwe Bornscheuer

Dr. Uwe Bornscheuer is a professor of biotechnology and enzyme catalysis at the University of Greifswald in Greifswald, Germany. Dr. Bornscheuer’s scientific career spans over 30 years, starting in 1985 at the University of Hannover in the study of chemistry. He has been a professor at the Institute of Chemistry and Biochemistry in the Department of Technical Chemistry and Biotechnology at the University of Greifswald since 1999.

Since the introduction of plastic to the world less than a century ago, microorganisms have evolved to be able to capitalize upon plastic as a source of carbon. In 2016, a Japanese group first reported the discovery of a bacterium that was observed to be able to degrade plastic PET. Dr. Bornscheuer has expanded upon this topic, conducting significant research regarding possibility to utilize PETase and MHETase enzymes to conduct this process in cooperation with a variety of researchers, including Dr. Gert Weber and Manfred Weiss at the Helmholtz Center Berlin (HZB). In 2019, their research was reported on the Science Daily for their remarkable discoveries in the development of MHETase and PETase technology to degrade plastic. Upon finding this article, our group contacted Dr. Bornscheuer, who was cited as a leading contributor of this research, in hopes of gaining insight on current academic efforts on this matter and hear his professional opinions.

Enzymes have been observed to have the ability to degrade plastic into its building blocks, the process of which Dr. Bornscheuer notes is similar in fashion to the degradation polylactic acid. Ongoing efforts to utilize enzymes to degrade plastic have been primarily working on genetically engineering enzymes to maximize their efficiency. Thus, understanding the structure of enzymes has become critical for the purposes of genetic engineering. The ultimate goal is to establish a system in which plastics can be consistently reused after their degradation by these enzymes, facilitating a closed cycle. Dr. Bornscheuer envisions the realistic implementation of this technology in specialized factory conditions. In such environments, plastic waste will be gathered and degraded, and the resulting products will be then synthesized to produce plastic products again.

Although Dr. Bornscheuer acknowledges the significant potential of this venture, he cautions that this in no way can be considered a ‘solution’ to the issue of plastic waste in the world. He especially underscores that its applicability is limited only to PET at the moment, and even such implementation must be restricted to highly controlled settings. Moreover, he stresses that existing methods to produce plastic, such as the use of crude oils, which despite being immensely environmentally destructive, are cheap viable options for corporations. As a result, due to these various options already favored by large corporations, enzyme technology must be further optimized to be economically competitive.

Dr. Bornscheuer believes many groups will be able to realize this technology in basic pilot programs in the next few years considering the vast progress that has been made. However, Dr. Bornscheuer firmly calls for the continued awareness and effort from consumers as well to “pay a few more cents for the environment”.

Dr. Mirończuk

Since our project pertains to the effectiveness of bacteria degrading plastic in rather extreme environments such as the cold, dark sea, our team conducted research on previous studies on the factors that affect the effectiveness of plastic degrading bacteria in marine systems. In the while, we found a research paper, Degradation of plastics and plastic-degrading bacteria in cold marine habitats, that not only shared the same urgent environmental perspective of our team, but also analyzed the efficiency of multiple bacteria and their enzymes on degrading plastic in the ocean. The paper answered questions on factors we had thought of before, such as the temperature of the environment, and raised several factors we hadn’t conjured before to the surface, such as the formation of the biofilm. Intrigued by the study, we decided to contact and interview one of the authors of the paper, Aleksandra M. Mirończuk to ask some questions. Sadly we were only able to hold an email interview with her.

Since the main purpose of our research was to learn the effects of the marine environment on the efficiency of biodegrading microorganisms, our questions focused mainly on the results of her research. The questions we sent revolved around the factors that would increase the rate of plastic degradation, the role of biofilms in the biodegrading process, and the possible impact such technology will have in the short and long future. Some questions were completely speculative as we wanted to see how realistic our expectations of the environmental influences our project will bring upon.

Her reply came very quickly and thoroughly. First, she addressed the problem of the bacteria not being able to attach to the plastic due to the plastic’s hydrophobic quality. Thus, in order to encourage the attachment of bacteria, one must increase the hydrophilicity of the plastic, which can be done by providing a calm and warm water environment with enough nutrition that can be provided using glucose, yeast extract, and a diverse mix of microorganisms. After the attachment happens, the microorganisms can form biofilms, and only then can they start the biodegrading process. She also mentioned the realistic biological impacts of nonbiodegradable microplastics as microplastics can move from the very bottom of the food chain up to the top, into the bodies of humans. She also suggested that the most suitable microorganisms for degrading plastic would be those that can thrive in low temperatures but do not necessarily have to be psychrophiles. In the end, she shifted her focus onto the current imbalance between plastic recycling and plastic production, and predicted that recycling plastic will change to using plastic as a carbon source to synthesize value-added products with the development of biologically engineered microorganisms that can produce important proteins, enzymes, or biodiesel.