Team:BOKU-Vienna/HP/Silver
Silver Medal
Introduction.
We were busy with several aspects in the human practices of our project. First, we worked out our Project Philosophy, looking for a target where D.I.V.E.R.T. can help in solving a real world problem. We found that D.I.V.E.R.T. could be very applicable in plastic degradation and went on in looking at the practical implications of that idea. We had an interview with the head of product management for Austria's leading plastics recycling company, which is summarized in the Environmental Impact section below. Then we talked with Dr. Vybiral, who works at the Ministry of Health and Women's affairs in Vienna about Law and Regulation of GMOs in the EU. Finally, Dr. Peter Weish, a scientist, author and environmental activist helped us work out the Ethics on how to apply enzymes engineered by D.I.V.E.R.T. in plastic degradation.
Compared to all alternatives, plastics are extremely resource efficient. This circumstance, combined with their remarkable versatility as a material, makes them an indispensable commodity. Therefore, plastic can be found almost everywhere: in packaging material as well as many common household items, but also in specialized products such as medical instruments and car parts. Manufacturing and processing of plastic is a huge industry employing over 1.5 million people in about 60 000 companies in the EU only.1 This market is expected to double again in the next 20 years.2 However, it´s the properties that make plastic so important - durability and longevity - that are also making it hardly possible to be degraded naturally. This has vast environmental implications. Research suggests that our oceans currently contain around 150 million tons of plastic3 and that by 2050 there will be more mass of plastic waste in the ocean than fish2. But there’s also economic implications. Plastics stay in their original form far, far longer than their average time of use, but still, 2.6 trillion dollars worth of plastic end up in our world’s landfills or are burned in incineration plants every year.4 The use of a long-lived material in a linear consumption pattern uncovers the need for an improved recycling system. Currently, only 14% of plastic packages are collected for recycling and through those recycling processes, only 5% of the original material value can be retained. This is because plastics are mostly downcycled to lower-value products, which then cannot be recycled themselves. With that in mind, it is no wonder that global recycling rates for materials such as paper (58%)5, iron and steel (70 – 90%)6 are far higher. Plastic as a material needs to be redefined significantly, to improve the environmental situation as well. Creating a lucrative after-use market for plastic materials can give great incentive to build up collection and reprocessing infrastructures, hence reduce the amount of material entering the natural environment.
As a new recycling strategy, microbial degradation of plastics could become feasible in the future. Many different bacterial strains, including species from the genera Pseudomonas, Rhodococcus, Clostridium and Butyrivibrio, as well as fungal strains from genera such as Aspergillus, Fusarium and Mucor are capable of degrading plastics. Next to natural polymeres, such as cellulose and lignin, biofilm formation on- and biodegradation of many different petrol based polymeres, such as Polyethylene, Polyvinylchloride and Polyethylenterephthalat, by microorganisms, has been observed.7 These strains can be isolated from contaminated soil8 as well as waste water.9 For further information about the environmental implications of enzymatic plastics recycling and different opinions on that topic, please check out the Environmental Impact section below.
[1]: Plastics Europe, Plastics – the facts 2014/2015: an analysis of European plastics production, demand and waste data (2016).
[2]: L. Neufeld, F. Stassen, R. Sheppard, T. Gilman, Eds., The New Plastics Economy: Rethinking the Future of Plastics (World Economic Forum, 2016).
[3]: Ocean Conservancy and McKinsey Center for Business and Environment, Stemming the Tide: Land-based Strategies for a plastic free Ocean (2015).
[4]: Ellen MacArthur Foundation, Towards the Circular Economy Vol. 2: opportunities for the consumer goods sector (2013).
[5]: International Council of Forest and Paper Associations, Statement on Paper Recycling (2017).
[6]: United Nations Environment Programme, Recycling Rates of Metals: A Status Report (2011).
[7]: V. M. Pathak, Navneet. Review on the current status of polymer degradation: a microbial approach (Bioresources and Bioprocessing, 2017, 4:15).
[8]: How to isolate plastic degrading bacteria from soil!
[9]: S. Yoshida, K. Hiraga, T. Takehana, I. Taniguchi, H. Yamaji, Y. Maeda, K. Toyohara, K. Miyamoto, Y. Kimura, K. Oda Supplementary Materials for A bacterium that degrades and assimilates poly(ethylene therephthalate) (Science 2016, Vol. 351,
Issue 6278, pp. 1196-1199). Recently, a new bacterium able to metabolize PET was isolated. Ideonella sakaiensis produces two enzymes that participate in the degradation process of PET: PETase and MHET hydrolase. First, polyethylene terephthalate (PET) is hydrolyzed by PETase and metabolized into mono (2-hydroxyethyl) terephthalic acid (MHET). Then MHET is taken up by the cell and hydrolyzed by a second enzyme into the two monomers which build up PET - ethylene glycol and terephthalic acid. These monomers are used for growth by I. sakaiensis. With our method D.I.V.E.R.T. we intend to enhance the catalytic activity of PETase. Having the next step in mind, we reflected upon fields that would benefit from efficient enzymatic PET degradation. For example in PET recycling, the monomers produced could be used for synthesis of new PET.
In order to investigate the feasibility of using GMOs for PET recycling, we interviewed the head of product management, Mr. Harald Pichler, of ARA, Austria’s leading company for collection and recovery system for packaging. We talked about advantages of PET in the recycling process, how to reduce the release of PET into our environment and the potential application of biocatalyzed PET recycling. Austria has a comparatively high PET recycling rate and Mr. Pichler talked contentedly about the waste collection system and the regularity of public campaigns. Conventional PET recycling is a well-established and well-performing process, enabling the repeated reinstatement of material. Amongst others, projects like “bottle-to-bottle”, in which food-contact PET is reused as food-contact PET, the most valuable category of plastic, make PET a successful and prominent material. Any new recycling method would have to be able to compete with high throughput rates of the current method. Therefore, Mr. Pichler does not see reason for establishing biocatalyzed PET recycling, whereas its application in niches of plastic recycling is conceivable. For example, recycling of mixed plastics and the purification of complex mixtures, resulting from pyrolysis, are current challenges, in which the use of enzymes could be meaningful. Overall, Mr. Pichler was very curious about the potentials of plastic degrading enzymes and after an intensive discussion, we came to the conclusion that even if not necessarily in PET recycling, there are still a lot of possible applications of plastic degrading enzymes left to discover.
After the interview with Harald Pichler, there were still many open questions. We could still imagine many possible applications for enzymatic recycling of plastics, though not all of them are feasible. Some members of our team thought that plastic waste should be collected from landfills and oceans, to be enzymatically disassembled in a closed reactor system. This is of course very work intensive, and may be ineffective because of microplastics, which is one of the reasons why the global plastic-waste problem could never be solved this way. Some, on the other hand, are of the opinion that the only possible way to rid our oceans from plastic waste is to engineer a marine organism to degrade plastics efficiently enough to fight the accumulation of plastic waste in our environment. This would, of course, mean releasing a genetically modified organism into the environment, with unforeseeable consequences. During this discussion, one very important question came up: does the application of D.I.V.E.R.T. count as genetic engineering? D.I.V.E.R.T. allows us to take a gene from any organism and mutate it randomly. The only difference to physical or chemical methods of directed evolution is that the mutation happens enzymatically and only to the target gene. Then, using novel techniques like the CRISPR/Cas9 system, researchers could theoretically replace the original gene from the native organism with our mutated version without leaving any scars in the DNA. In the end, nothing completely unnatural would have happened, we had only sped up evolution. We decided to contact the law-makers and ask them for their opinion on our project. Dr. Dietmar Vybiral works at the Ministry of Health and Women’s Affairs in Vienna. He acquired his doctoral studies in genetics and worked as a postdoc for 1.5 years at the University of Vienna before entering the ministry. There, Dr. Vybiral’s job is to represent Austria at the level of the European Union in decisions regarding genetically modified organisms (GMOs) or products thereof entering the EU. Basically, he is involved in any discussion about whether GM-crops should be released for cultivation in the EU and whether products from GMOs are safe for consumption and release in the European market. The questions we came to ask him are a prevalent point of discussion in the European Union. With the rise of the so-called new plant breeding techniques (NPBTs) using CRISPR and oligonucleotide-directed mutagenesis (ODM), it is suddenly unclear, whether crops carrying targeted point mutations or gene deletions should be defined as GMOs or not. In that regard, Dr. Vybiral claims that, if those techniques were not supposed to be a form of genetic modification, he would not know what he had studied, however, the question remains whether or not those organisms should fall under GMO regulation. This is currently being decided by the European Court of Justice, as many gene-edited plants are up and ready for field trials. In any case, Dr. Vybiral embodies the public notion of Austria on GMOs, which means that he votes against GM-crops and products entering the country. When asked about what could be done to better the general opinion of GMOs in Austria, he anticipates that there is little hope, but NPBTs are a new chance to lead a reasonable discussion this time. In his personal opinion, he thinks that genetic engineering is a very exciting and beneficial field of research, with many products being necessary to society, however he does not want GM-crops growing on Austrian soil as they are almost impossible to constrain. He is also sceptical about NPBTs, saying that they are not always as completely accurate as some people might imply. Technologies like CRISPR and ODM can sometimes alter the genome in unknown places and this possibility is very hard to disprove, as developers of GMOs would have to supply whole-genome sequences of any crop or other organism they want to release into the environment. He argues that all current genome editing technologies can leave small traces of foreign DNA in the cells, which likewise goes for D.I.V.E.R.T. Therefore, he concludes that organisms carrying genes mutated by D.I.V.E.R.T. should by law count as GMOs. However, if the European Justice Court rules against strains from NPBTs counting as GMOs, countries are bound to follow, which may heavily go against the grain of the European population and even national legislations.
Some of our team-members went to the Austrian Ministry for Transport,
Innovation and Technology to talk to Dr. Vybiral
Plastic waste piling up in the ocean is a tremendous problem for our ecosystem and thus our future. In trying to help solve this problem, we found that currently legislation offers fairly unstable ground for us to move on. In the end we ourselves have to ask the following question: could synthetic biology offer a viable solution for this or will it cause more damage? In order to assess the potential risks and benefits, we interviewed Dr. Peter Weish, a scientist, author and environmental activist. He was a member of the Advisory Board on Gene Technology in Austria and lectured on human ecology and at present on environmental ethics. We talked about ways to reduce the accumulation of plastic in the environment and contemplated on the ethical aspects of releasing GMOs into the environment. One of our arguments for using D.I.V.E.R.T. to solve real world problems was that evolution takes place naturally – so our project would only accelerate a natural process and therefore, by design, could not cause any issues. Dr. Weish argued that we, as the winners of a long-going evolutionary fight for survival, cannot claim D.I.V.E.R.T. would do no harm to the environment. “Nature is merciless and stops at nothing”, he stresses. Also, the difference between a natural and a human-induced process lies less in its impact, but more in the ethical aspect of it. Humans are not responsible for the death of living beings during a natural evolutionary process. However, they would be responsible if it is an artificial evolution caused by methods like D.I.V.E.R.T. He warned us against releasing GMOs into the environment without knowing its influence on the ecological system. People have already tried to ‘improve’ ecosystems before, resulting in negative and sometimes dramatic developments. Nobody knows how a GMO might affect nature. Even if there is a study that shows the alleged innocuousness of a GMO, scientists need to be critical. In accordance with the precautionary principle and the safety principle, potential damage has to be avoided and every study has to be carefully examined even if it contradicts the popular opinion. For clarification, he names an example: for a long time, based on observational data, many scientists believed that radiation underneath a certain threshold is completely harmless. Only when John Gofman’s research allowed us to fully understand the potential health risks that can occur even at small doses, the misbelief of a threshold was reluctantly discarded. However, the implications of releasing a GMO into the natural environment are something we cannot fully understand. We cannot predict the consequences of such a release and would only notice them afterwards, when the change is already irreversible. As scientists, we must ask ourselves what could happen in the worst case and whether or not we could take responsibility for this. This means, that we have to include what we do not know into our considerations. But, even though Dr. Weish is against releasing GMOs, he still supports experiments and research in the field of genetic engineering in order to improve our understanding of molecular genetics. Dr. Weish agrees that the precautionary principle stands in the way of possible innovations.
‘Innovation per se is neutral’, he clarifies, ‘it would be a mistake to equate it with improvement’.
A trial and error strategy with potentially catastrophical consequences should not be confused with progress. Opposing the release of GMOs therefore is not anti-progressive, but in fact securing progress. In order to evaluate the benefits and risks of an innovation there are several questions that need to be answered, for example: Which advantages and disadvantages does it bring and for how long? Most important in the assessment is the future prospect. What might be a good idea today, may turn out to be a terrible disadvantage in the future. According to Dr. Weish, we have to take an alternative approach for the reduction of plastic waste. There need to be strict regulations on the sale of plastic. It should only be exported to places where its waste disposal is implemented. First and foremost, the plastic producer should be held responsible for waste disposal. When we pointed out, that this might lead to increased prices of the product, he introduced us to the so-called ‘ecological bonus concept’. A high tax is collected by the state, which later gets equally refunded. Someone who consumes as much or less than average does not have to pay additional costs and might even get more money back. Someone who wastes more than average, in most cases the plastic-producing companies, has to pay taxes. This way, less fortunate people are not disadvantaged and as a side effect, it propagates people to be more careful with consumption. The problem of excessive plastic waste has to be tackled not only in a single state, but also on a global scale. For this reason, the UN published the 17 Sustainable Development Goals, where one goal is to ensure sustainable consumption and production patterns. ‘Peace is only possible with sustainable development’, Dr. Weish remarked. But also on a personal level, one must try to reduce his or her ecological footprint, the demand on nature.
Second person from the left is Dr. Peter Weish. He told us his opinion on the ethics of our project
Philosophy.
Plastic is a central material to all of our daily lives.
Environmental Impact.
Law and Regulation.
Ethics.
