Team:CIEI-China/HP/Our Story
In order to obtain more accurate and up-to-date data of the salt concentration in food waste, our team decided to collect samples from the canteen of China Agriculture University, where we conducted our experiments. On the evening of 28th July, after most students finished their dinner, five team members, carrying several test bags and glass bottles, headed to our destination.
After receiving the admission from the manager of the canteen, we started to collect samples. Two boys of us put on the gloves to prevent contaminating waste samples. They dug their hands into the full garbage bin to take out solid food waste. Then we separated approximately 100 grams for one test bag and collected three repeats at each sample site. After carefully sealing the bags, we also collected 80 milliliters of liquid food waste in each of three glass bottles to record the salinity data of different types of food waste.
In order to avoid decay, we quickly stored our samples in the fridge of the lab. Next, we sent our samples to a professional salinity test site, Agriculture Science and Biology Research Center, to collect the salinity data for the future experiments.
According to our analysis, we found that the result was not convincing enough to support our hypothesis. Thus, in the whole month our team visited more sample sites and collected new samples. To make the results more accurate, we divided our samples into three groups on the basis of the sample sites, family kitchen waste, canteen waste and restaurant waste. On 19th, 20th and 21st, Oct., we visited more than 20 restaurants and 10 canteens and finally collected 12 samples. Meanwhile our classmates helped us with 6 family kitchen samples.
The most difficult part is getting the restaurant samples since half of the managers rejected to provide samples, either because the restaurant cannot understand the purpose our research or the managers was afraid that the experiment results would affect them. Sometimes we needed to explain our project in simple language, academic language, and concise language to different managers. The other difficulty is the canteen sample. Some of the school cafeterias don’t have a strict waste sorting. There are chopsticks and some plastic bottles in the trash can. Other cafeterias with a strict sorting have a clean can with a hole for pouring wastes which is impossible to collect samples.
After the collection, we obtained diversified and a big amount of samples, which provides a strong support for us to build a more realistic and reasonable database. The salinity of all these different samples are higher than what we thought.
1) Stepping into Green Community
After reading through abundant scientific documents and records, we figured out that high salinity would, to some extent, affect the fermentation of microbes during waste disposal process. Our team decided to learn about the development in contemporary waste disposal for further studies, so we chose Min An community as our first social research target. In order to have a thorough understanding of waste disposal and their difficulties in the Min An community, which was an exemplary experimental site for environmental friendly management of food waste.
2) Learning a New Method
On July 27th, five members of team CIEI-China visited the waste disposal machine, which uses the method of anaerobic composting for food waste treatment, in Min An green community.
The machine consisted of four parts: lifting container, fermentation space, air withdrawal device, and air purification tower. From our observation on the entire procedure and discussion with manager, Mr. Zhang, we learned that combination of these equipment was able to ferment and dispose the food waste into the extremely effective organic fertilizer in twenty-four hours, which could definitely meet the demand of plant growth in farms. Firstly, people put the kitchen waste into the lifting container, which automatically transferred the waste into a large fermentation space. Next, the computer monitored the range of the temperature from 60°C to 80 °C and regulated the moisture to an ideal range from 50% to 60% by adding carbon fiber to 10% of total mass. After the computer created optimum condition for microbes to work, the stirring arms inside the fermentation space helped to make the substance evenly heated; at the same time, the hyper-thermal aerobic microbes, including Lactobacilli, Yeasts, Bacillus natto, and Bacillus subtilis, cooperated to degraded and dispose the solid food waste into powder-like matters: biochemical humid acid, which were the raw materials used to produce agricultural fertilizers.
Besides the main fermentation process, the air withdrawal device could provide enough air for microbes' working and air purification tower could prevent noxious air (e.g. carbon monoxide and sulfur dioxide) from polluting the atmosphere as only water vapor would enter the environment at last.
3) Space for Improvement
Since our project focused on the salinity of the microbe, we asked the manager about how his method decreased the salinity of the food waste. However, he replied that his company did not pay much attention to the salt content in the food waste. He suggested that the high salinity might affect the efficiency of the microbe and encouraged us to further our research. Then Mr. Zhang generously commented on our project design and gave us precious suggestions. He advised that we should pay heed to the stability of our microbe as the gene mutation is common among bacterium, which might greatly influence the microbes' function. As a result, we decided to take gene stability into account during our experiment design.
1.The total idea we got
Through this total investigation, the data we obtained confirmed that our research will benefit the environment and human’s life quality, which is really meaningful. Furthermore, the investigations provided us the clue in setting salinity gradients for the test of our modified yeast’s survivability and effectiveness during decomposition of food wastes. The exploration in the green community also gave us some idea in industry and the manager’s experienced suggestion did gave us some inspiration.
To enhance the social impact of our idea, we held speeches in high-school classes in Beijing. Several teammates gave the speeches in biology classes of Beijing 101 International Department and Beijing Changping New Oriental Foreign Language School. In every speech, we mainly introduced the history of iGEM, and how creative the match is—lots of innovation are originated from this match. Then, we introduced our project—how to effectively decompose the kitchen waste with low osmotic pressure (high salinity) osmotic pressure. We basically talked about the factors which can affect the efficiency and the ability of yeasts in kitchen waste decomposing, and our own solution. We successfully managed to accomplish the propaganda of iGEM and showed our project.
To expand our influence in the society and let more people participate and focus on our project, we also need some financial support. We wrote an article on the internet to describe what synthetic biology and iGEM are, and to introduce our own project. Our team members also introduced our project in the real life: they visited some companies which are related to biology and explained our project to them. We got the funding from Nanjing Zhengbeicehui Equipment Inc., Hunan Tianxingjian Project Management Inc., Shanghai Songyuan Cork Foam Inc., Beijing Shiyuan Business Inc., Kanglihua Company and Beijing Huaxiafengxing Advertisement Inc, etc. Through this practice, we not only challenged ourselves in negotiating with adults, especially the managers of some enterprises, but also expanded our influence in the society such as the marketplace. We played a role in promoting the influence of synthetic biology and iGEM.
On July 20th and 21st, 2017, our team took a field trip to Tsinghua University and Peking University to attend a meeting with instructors and their former iGEMers. We explained our project idea and they warmly offered us some specific suggestions in our experiment design and human practice. Informed that our attempt was to improve the salt resistance of the yeast and increase the efficiency of food waste disposal, they generously provided us some information from the former teams which had studied the similar project from a different perspective. After the communication, we had a pleasant dinner and appreciated their help. Then they offered their contact information to us, looking forward to our further improvement.
Most of our family and community have no idea about the synthetic biology. We gave lectures to our parents and our neighbors. Most of people are confused with or held some wrong opinions about synthetic biology. Through our introduction and explanation, they realized that synthetic biology is not as horrible or scary as what they used to think. We changed their opinions, also taught them some basic knowledge of the synthetic biology that they have never thought of. We also helped many children understand that biology is really useful and interesting. We not only introduced our project, we also spread the influence of the synthetic biology and iGEM.
In February, we brainstormed the idea of our project. During this time, we visited the Institute of Zoology and discussed with Dr. Wei, the expert of Conservation Genetics, for advice. We made clear of the prospection of idea with the professors; and they confirmed that our research topic will be very meaningful in the society and gave us some very useful suggestions.
Besides the idea-exchange seminar we had with the experts in Institute of Zoology, Chinese Academy of Science, before the experiments in summer, in August and September we contacted many iGEM teams in China and invited them to attend the CGEM (China Genetically Engineered Machine) Forum in October, which is organized by our team together with CIEI-BJ.
On 4th, Oct. the First CGEM Forum was held in the meeting room “Reddish Lake” on the 4th floor of WenJin International Hotel. In respond to the invitation, two high-school teams (HFLS-H2Z-HangZhou and RDFZ-China) and one college team from Beijing institute of technology came to the forum. In total, more than 70 teachers and students attended the conference. Our team was in duty of welcoming, leading the people, setting the room, as well as doing signing up for visitors.
During the seminar, teams first gave presentations on their own topics on the stage; then, the professors provided advice and improvement directions from many aspects including topic (purpose, experiment design, influence, potential danger), power point (words, color, number of pages), and speech (content, volume, order of speaker, motion, time management). Dr. Li, Dr. Cheng and Dr. Xue kindly provided every team with suggestions and opinions.
Through communication with members in other teams after all speeches and comments were given, we gladly heard that they considered the forum as a useful chance to modify their own presenting process. “The suggestions from Dr. Wang made us jump out of the box easily and immediately came up with new idea about how to design our wiki,” said the leader of CIEI-Beijing, “quite amazing!” As an old saying goes “bystanders always know better”, the improvements mentioned by the professors, indeed, sparkled every single teammate’s mind, provoking them to find better solutions to their problems and move forward.
What’s more, idea-sharing seminar gave the forum members chances to exchange ideas about poster design and production, as well as listen to advice and stories from experienced professor, who is now running his personal bio-company.
In October, some of our group members went to the School of Pharmacy in Southern Medical University in Guangzhou to help our sister team CIBI-BJ by helping them collect the human body test data. We compared the effect of citronellol on mosquito repelling by letting them bite us. Although this is not an comfortable experience, we felt very fulfilled by helping our sister team.
In 2017 May, our team, CIEI-China, teamed up with the CIEI-BJ team to collect trash samples. The members of our team and the CIEI-China players first arrived at the local residential quarter. Then the members of CIEI-BJ and CIEI-china went from door to door to ask local residents for their kitchen waste. Members of our two teams also collected samples from trash cans in the local communities. After a lot of inquiry and collection, our two teams successfully collected enough trash samples for us to test and analyze the salt concentration in food waste.
As the Giant Jamboree approached, our team’s preparation work was also coming to its end. For the last part of our preparation, we needed to build a model for the project. After searching for relevant papers on the Internet, we came up with an excellent idea about designing a mathematics model of the salt influence on the production of VFAs, the change of VS/TS, and the percentage of SCOD during anaerobic composting.
At the same time, since we had decided the topic of our model, we hoped to communicate with other teams in order to receive some comments or suggestions of improvement from them. Luckily, we successfully got in contact with Team Shenzhen_SFLS from Shenzhen, China on Wechat. Their project was about changing B-Raf V500E gene through CRISPR-Cas9 and thus curing melanoma, so they decided to build models of the contagion efficiency of melanoma as well as medication spread efficiency.
Our team and Shenzhen_SFLS briefly exchanged our model ideas. During the communication, we discovered that their team mostly based their model on graphs, which enlightened us to draw three graphs of VFAs, VS/TS, and SCOD vs time respectively, in an attempt enrich our model and also more straightforwardly support our argument about the hyperosmosis influence on anaerobic composting.
Although it was only a brief communication with Shenzhen_SFLS, they really helped us a lot. We sincerely appreciated the favor, and are looking forward to meet them on the Giant Jamboree.
Because it is hard for us to have face to face communication with other teams, we had a We-chat communication group FAFU CCiC with them. This group consists many teams, like BIT-CHINA. We shared our idea with many college students, and they gave us many professional suggestions and kind help.
Our product can help the environment in three ways. First of all, with our modified yeast, food waste decomposition rate will be greatly increased, and then we no longer need to worry about the soil pollution which is brought by traditional kitchen waste digestion-landfill. As the amount of kitchen waste that is digested by landfill decline, salt and other toxicant will gradually stop entering into the soil. Secondly, after decomposition by our genetically modified yeast, some of the useless kitchen waste might be efficiently changed into biological fertilizers. This type of biological fertilizer not only enhances crop production, but also can help the soil maintain a high fertility. Last but not least, burning of kitchen waste can be replaced by our decomposition method, which will effectively relieve the current unpleasant situation of air pollution.
Our project is aimed to increase the tolerance of yeast in hypertonic environments during food waste decomposition. With our modified yeast, survivability of yeast and their decomposing efficiency can be greatly increased. Currently, most of the companies have to add new yeast periodically to keep the decomposition rate. With the help of our yeast, the companies can save more costs by reducing the needs of large amount of yeast and increasing the decomposition efficiency.
Because of the effectiveness of our modified yeast in food waste decomposition, people will be able of enjoy a safer and more comfortable life in a fresh and clean environment without the negative effects caused by the food waste.
