Team:PuiChing Macau/Human Practices
Integrated Human Practices
Over the summer, we have learned about the basic synthetic biology, both in the theory and practical experiments, which get us ready for current project, and the disturbing fact of EDC in affecting human and ecological system. EDC issue would be separated into two levels:
1. wastewater treatment from factories and cities
2. the existing EDC pollution in nature and the current water transport system. To tackle such a problem, we chose to focus our efforts on developing our new engineered bacteria strains, specifically with laccase production. To provide a better real-world application, we also designed and 3D printed 2 different biofilter prototypes for our strains, as the solution to the current need in Macau and the world.
Throughout the project, we have engaged conversations with experts and stakeholders in different fields, from a wastewater treatment plant to a bottled water company and government departments. Herein, we document the process of our human practices work and how this shaped our project at different stages.
Interview with Institute for the Development and Quality, Macau
The initial idea of the project was to establish an engineered E.coli strain with Laccase production to target the EDC pollution. In this, we would conduct genetic manipulations to boost productivity. Such manipulation would mainly target the alternation in the metabolic pathway.
To better understand the background of our project, we interviewed a consultant from The Institute of the Development and Quality of Macau, who is specialized in the water quality monitoring and provides consultancy service to environmental protection projects. Through this interview, we have understood that with the rapid development of Macau in the past decades, the increase of population and visitors (to annually 30 million visitors in 2017) has resulted in a massive increase of water consumption and plastic waste, these overwhelmed the wastewater treatment plant in Macau and wouldn't completely remediate wastewater. On top of this, the EDC is a type of relatively new pollutants that have not been detected by conventional testing items in Macau and nearby regions. It would benefit the community if EDC is included as a routine test item and has a particular method designed to remove from water. In regards to our project, he confirmed our idea is with great potential to target to the current issue, however, we will have to consider the overall laccase efficiency of the strain and the time required for EDC decomposition.
The current application of biofilter to remove chemical is restricted by the bacteria engulfment of chemicals. It is possible to induce cell lysis and extract laccase from a medium, however, this method is expensive and not sustainable. A secretion system may be able to reduce costs in the upscale significantly. Therefore, we decided to shift our focus to downstream process improvement by adding a secretion signal peptide. His advice was of a significant impact on the shaping of our project and allow us to realize the exiting EDC pollution is in both wastewater and drinking water.
Visit to Macau Transrontier Industrial Park Wastewater Station
How the biofilter design merge.
With the information which support our project, we decided to process. In order to understand how our engineered strain would apply in real-world scenarios, we visited The Macao Transfrontier Industrial Park Wastewater Treatment Plant. This station went into commercial operation in early 2009 and was built to have a treatment capacity of 12 000 cubic meters (m3) per day. It also adopts biomembrane microfiltration (membrane bioreactors (MBR)), which is an advanced technology and has four treatment lines equipped with biomembranes. Through the induction visit tour, we learned the basic current water filtering techniques and the procedure of how wastewater is turned into clean water.
This provide us the basic information of how the biofilter is operating in the waste treatment plan and moreover, this visit inspired us to design our filter to degrade EDC, and the subsequent modeling. In this, we also receive advice from the lab technician suggesting that the EDC treatment process should take the pH values and temperature of the wastewater into consideration.
Consult Macao Government Department - Bureau for Environmental Protection Services & Miriam Group
"Further direction with drinking water and water resource During the previous interviews and the awareness rise from our public education engagement, we realize that there are certain risks that EDC material would enter our water resources and water transport system.
Therefore, we have contacted that The Bureau for Environmental Protection Services of Macau (DSPA), which is responsible for the study, planning, implementation, coordination and promotion of environmental policy. Regarding the information from their feedback, we understood more about the whole picture, including the usual PH value, temperature, and flow rate of the wastewater, and the condition of water storage and tunnel system. In these, we found out most of the water tunnels are PVC tunnel, which would have EDC material release in water.
To understand if we are at risk of drink EDC water, we visited Miriam Group, which is a local potable water resource company. This company mainly take charge of the sales and packaging of water. But during the whole process, they would also monitoring water quality. However, we discovered that while they have detected most of the important pollutants, EDC was not on their list.
Water bottles and PVC tunnels are plastic which would release material like nonylphenol, a type of EDC, into water. With the limit of device to prevent EDC from getting into our drinking water (bottled water or tap water), we are at risk on drinking EDC polluted water. This further strengthen our believe that a system for filtering or degrading this kind of chemical but targeting our water resources. In considering such filter, we were initially worry limitation of current engineered E.coli strain due to the outdoor temperature and harsh environment. However, we did spot an opportunity to use sunlight as an extra energy source and aim to develop new engineered cyanobacteria strain with Laccase secretion. This design would being suitable for bioremediation in wastewater treatment and different water sources.
Visit to Macau Water Supply Company Limited
New pototype for Cyanobacteria biofilter
In order to confirm the current EDC risk in our drinking water, we visit the Macao Water Supply Company Limited (SAAM), and discussed more about the sustainability and applicability of our team’s project.
During the visit, we had the opportunity to take a closer look at their laboratories and water treatment plants. All apparatuses shared the general purpose of examining sample water, one of which was to examine it by means of microorganism. We also introduced our report to them in detail, discussed with them, and tried to re-optimize our project based on their experience, and discussed which process should our project added in if it can be applied to Macao's sewage treatment process.
After our visit, we learned that the company had almost no tests on EDC, which meant they had no equipment to prevent it from entering our system. This has increasingly strengthened our belief that Macau urgently needs a system to filter or degrade this chemical. In addition, we were also suggested 1. to examine if our engineered cyanobacteria strain would also secrete toxins; 2. to monitor the stability of proposed strain, and continue to test their functions, to avoid the loss of our construct in generation. In regarding our proposed biofilter, it would be put in the pre-treatment of water treatment. This encourage us set up our final goal: place our Cyanobacteria biofilter in industry.