Team:NAU-CHINA/Integrated Human Practices
Integrated Human Practices
Introduction
Introduction
Selenium is one of the essential trace elements in human body. As a component of many enzymes, it has the functions of resisting diseases, delaying aging and enhancing immune. Selenium and vitamin E play a synergistic role in the antioxidant function of organisms and the maintenance of cell membrane function. Selenium deficiency can cause leukomyopathy and liver necrosis in domestic animals[1]. In addition to the use of inorganic selenium supplements, the most common way of selenium supplements in our daily life is to supplement selenium through plants. Selenium in animals is also obtained from plants. Therefore, increasing selenium content in plants is of great significance to the whole ecosystem.
In daily life, selenium is often found in soil and wastewater in form of selenates and selenites. At the beginning of the project, we hoped to obtain selenium by dealing with selenium pollution in soil containing a large amount of selenate and selenite from the power plant, ceramic factory and other areas prone to selenium pollution. However, after a series of interviews and surveys, we found that 1) selenium pollution only exists in a small number of regions, 2) selenium in the polluted soil is not as abundant as we expected, 3) it is hard for us to extract selenium from the complex composition in the soil, and 4) selenium pollution needs to be treated uniformly as hazardous waste. After literature review and re-evaluation, we finally changed our focus of study.
Selenium in form of selenates and selenites cannot be used efficiently by humans and other organisms, which leads to the waste of selenium resources in nature. The uneven distribution of selenium resources is a global problem, which poses a threat to the health of local residents, animals and plants. Therefore, we hope that through the method of synthetic biology, the modified engineering bacteria will be used to reduce selenate and selenite in wastewater, so as to recover SeNPs. SeNps is easier to be absorbed by the organism, easy to transport and transfer, and has a higher utilization rate, which make it possible to realize the higher efficiency of the circulation of selenium element and play a greater value. It also provides a new possible way to change uneven distribution of selenium in the world, which help to solve the health problems of people and other organisms caused by abnormal selenium content.
Fig.1 Selariumsy cycle in theenvironment near the surface of the earth
[1]王翔朴,王营通,李珏声.卫生学大辞典:[M].青岛:青岛出版社,2000
Stakeholder model
Stakeholder model
Based on the analysis of project stakeholders, we established the following relationship model, and interviewed and consulted the three parties respectively.
Fig.2 The stakeholder model we established
Stage1 Identification of key problems and challenges in selenium pollution
① Present situation and sources of selenium pollution in China
Stage1：Identification of key problems and
challenges in selenium pollution
① Present situation and sources of selenium pollution in China
We analyzed the status quo and sources of selenium pollution in China via literature review. Natural sources include weathering of selenium-bearing rocks, leaching of soil, and volcanic eruptions. Anthropogenic causes of selenium pollution include coal burning, minerals, agriculture, oil refining, pesticide production and glass manufacturing.
② Soil reaserch
Stage1：Identification of key problems and
challenges in selenium pollution
② Soil survey
In order to further understand the presence of selenium in soil, we carried out soil sampling and analysis in different areas of Nanjing, and found that most selenium in the soil was in form of selenate and selenite. Except for the soil around power plants, the content of selenium in other soils was at normal level. This was far from what we expected, so we decided to interview professors specialized in environmental soil to help us analyze and evaluate this phenomenon.
Fig.3 Soil sampling performed around power plants
Fig.4 Soil sampling was conducted around abandoned factories in the outskirts of Nanjing
③An interview with Professor Liang Dongli to further clarify the direction of our project
Stage1：Identification of key problems and
challenges in selenium pollution
③An interview with Professor Liang Dongli to further clarify the direction of our project
Fig.5 Photo of Professor Liang Dongli
Professor Liang's main research direction is soil environment. She focuses on the environmental behavior of heavy metals in soil and their toxic effects and remediation through food chain. In recent years, studies have been focused on the morphological transformation, migration and effectiveness of selenium in soil-plant systems, and a lot of work has been done on environmental chemical behavior of heavy metal pollution, and pollution prevention and control.
We interviewed Professor Liang Dongli, who works on similar research direction with our project, through email. We introduced the prototype of our project and hoped to get some suggestions. Professor Liang answered the questions in the email very seriously, and said that our idea was very good. She hoped that we could work hard to get some results. In the meanwhile, Professor Liang pointed out that we should firstly clarify the various complex components in the soil, and judge whether it will have a certain impact on our engineering bacteria. This interview reminded us that before the experiment, we should first determine whether soil composition will affect our engineering bacteria through literature review or preliminary experiment. As for the significance of dealing with selenium pollution, Professor Liang thought that selenium pollution exists in only few areas in China. We cannot only deal with selenium pollution, but also try to solve more problems through our project.
From her advice, we realized that the complex soil composition would have a great impact on us, and we do not have a good way to deal with it at present. So, we began to try to change our source of raw materials, using waste water to obtain selenium.
(Professor Liang answered our questions carefully, and pointed out the direction of experiment at the beginning of our project.)
Fig.6 Professor Liang Dongli replied to our email
④Connection to WHO philosophy and attention to globalization
Stage1：Identification of key problems and
challenges in selenium pollution
④Connection to WHO philosophy and attention to globalization
After the interview of Professor Liang, we began to realize that selenium pollution was not as widespread as we had previously realized. Does obtaining selenium from selenium-contaminated soil and wastewater make the most sense for our project? Is there more scope for our project?
The concept of One Health offered us some hints. One Health is global health, which combines multidisciplinary knowledge to address regional, national and global health issues and improve the health of people, animals and the environment.
In the process of communicating with experts and associations related to One Health, we recognized that the WHO concept is closely related to One Health, namely, the idea of health globalization. From this perspective, we found that selenium affects humans not only directly but also through the whole food chain of the ecosystem from the environment to the animal/plant to the human body. Selenium takes different forms in the environment, of which selenates and selenites are the most toxic forms, accounting for 95% of selenium toxicity.
After this contact, we hope to promote the one health concept among the iGEM teams through a collaborative approach.
Selenium toxicity in plants and animals for human consumption is also a concern because the selenium cascade begins when animals absorb and store large amounts of selenium from plants. This set of questions provoked our thinking about whether our project had broad implications on a global scale. Through our project, can we promote the circulation of selenium among people, animals and the environment, and can we play a certain role in improving the global selenium health? Could the SeNPs we get from recycling help more people improve the health problems caused by selenium deficiency?
Fig.7 The World Health Organization icon
⑤ From China to World
Stage1：Identification of key problems and
challenges in selenium pollution
⑤ From China to World
To verify our idea, we began to learn more about the status of selenium worldwide, and learned that the natural distribution of selenium is not uniform across the globe. For some it is scarce, but for others it needs to be removed from the environmental medium. Countries and regions such as Ireland, parts of the US and India are in the toxic range, while Yugoslavia and Finland are deficient[2]. With the spatial variation of selenium, daily selenium intake varies from country to country. For some parts of the world, the presence of selenium is scarce, and thus raises problems of nutritional limitation rather than toxicity. However, there are still some areas where selenium content is too high or abnormal due to pollution, which will also affect the health of people and other organisms.
With this in mind, we believe that the project design we envisioned is of global significance: solving the global selenium imbalance and health problems caused by it through recycling selenium from soil or water to convert it into SeNPs. Therefore, the original intention of our project began to expand from dealing with selenium pollution to promoting efficient recycling and utilization of selenium.
Fig.8 Outline of occurrence of selenium in different regions of the world as selenium-deficie
[2] Gebreeyessus, G. D. , F. Zewge . A review on environmental selenium issues.SN Applied Sciences 1.1(2018).
Fig.9 Availability and inadequate risk of dietary Selenium in Africa
⑥Interviews with Professors specialized in resources and environment about the feasibility and significance of the global cycle of selenium
Stage1：Identification of key problems and
challenges in selenium pollution
⑥Interviews with Professors specialized in resources and environment about the feasibility and significance of the global cycle of selenium
We interviewed Professor Fang Di, an expert on resources and environment, to verify the feasibility of our idea and get some suggestions.
Fig.10 Interview with Professor Fang Di
Professor Fang analyzed the current global selenium status and the significance of selenium efficient cycle, and pointed out that due to the complex soil composition, the content of selenium is relatively small, so the recovery of selenium from soil could be affected by many factors, being extremely difficult and at high cost.
Then, we began to understand the presence of selenium in wastewater and carried out relevant sampling and inspection. Finally, we decided to treat the standardized wastewater discharged by factories. At this point, we formed a clear idea of our project.
Fig.11 Industrial wastewater
Fig.12 Experimental treatment of wastewater
In daily life, selenium often exists in wastewater in form of selenate and selenite. For humans and other organisms, selenium in these forms cannot be used efficiently, resulting in a waste of natural selenium resources. At the same time, when selenate and selenite content is too high, it will cause selenium pollution in water. At present, the methods of selenium recovery from anthropogenic sources mainly include microbial selenium recovery and phytoremediation, but both have defects. Therefore, we hope to use the concept of synthetic biology to reduce selenate and selenite with modified engineering bacteria, and generate SeNPs that is easy to transport and can be used efficiently, so as to realize "turning waste into treasure" and attempt to solve the problem of uneven distribution of selenium in the world. The recovery of SeNPs is also of great significance for improving the growth status of selenium-poor plants and increasing the yield of selenium-rich plants, and is expected to provide a new treatment for preventing selenium-deficient diseases.
Stage2 Stakeholder Survey and Interview; Solution Design
① A questionnaire survey to start the stakeholder survey
Stage2：Stakeholder Survey and Interview; Solution Design
① A questionnaire survey to start the stakeholder survey
The respondents who filled out the questionnaire were categorized by age, educational background and occupation. They were expected to be give answers to the same question from different perspectives.
Through the questionnaire, we know that people have high expectations for the application of SeNPs in human health care and plant fertilizer. In daily life, in addition to the use of inorganic selenium supplements, humans obtain selenium mainly from plants. So do animals. Therefore, it is of great significance to improve the selenium content in plants for the whole ecosystem and human health.
We initially chose to improve the selenium content in plants as the main purpose of our project, trying to apply selenium to its enrichment in plants after obtaining SeNPs by recycling selenium element, so as to alleviate the selenium poverty in some areas.
② Consultation with Professor Li Ganghua about Selenium-rich rice cultivation in Majiang (Our university's counterpart poverty alleviation unit)
Stage2：Stakeholder Survey and Interview; Solution Design
② Consultation with Professor Li Ganghua about Selenium-rich rice cultivation in Majiang (Our university's counterpart poverty alleviation unit)
Fig.13 Photo of Professor Li Ganghua
Introduction: Professor of Nanjing Agricultural University.
Mainly engaged in crop physiology ecology and rice high yield, quality, efficient cultivation teaching and research work.
Member of Water-saving
Agriculture Expert Panel of Ministry of Agriculture and Rural Affairs.
After consulted Professor Li, we learned the general way to make up for selenium deficiency. We finally decided to focus on the application of SeNPs leaf fertilizer. Compared with traditional selenite fertilizer, SeNPs has small particle size, good penetration conversion rate and high safety performance, which is the most safe and reliable at present. Using SeNPs fertilizer not only reduces the release of toxic selenite, but also improves the utilization efficiency of selenium element. The application of SeNPs foliaceous fertilizer is also consistent with our concept, that is, to recover selenite in form of pollutants and convert it into green and environmental-friendly SeNPs products. He also reminded us to consider the cost aspects and other issues, which provided ideas for our next research work.
Fig.14 First email to Professor Li Ganghua
Fig.15 Professor Li Ganghua’s reply to our first email
Fig.16 Second email to Professor Li Ganghua
Fig.17 Professor Li Ganghua’s reply to our second email
③An interview with a government official in selenium-deficient areas to understand their intention of productization of our project
Stage2：Stakeholder Survey and Interview; Solution Design
③An interview with a government official in selenium-deficient areas to understand their intention of productization of our project
Due to the COVID-19 isolation rules, our interview was confined to limited areas. Finally, we conducted an interview with Ms. Gao Xia, a senior agricultural expert from Xinzhou Agricultural and Rural Bureau in Shanxi Province, China. In Xinzhou, Shanxi Province, a lot of lands are selenium deficient due to the geographical environment.
We introduced to Ms. Gao Xia our project design and the specific method of applying selenium-rich fertilizer. Ms. Gao Xia showed a strong interest in this and asked us in detail about the production process of SeNPs. She encouraged us to continue our efforts, and pointed out that our project must have great significance and application value. This gave us a great boost.
Ms. Gao Xia also reminded us that we should pay attention to product costs and transportation in the process of product transformation, which becomes one of our concerns in the future.
Fig.18 Interviews with government staff in selenium-deficient areas
④Interviewes with farmers in selenium-deficient areas to understand their intention to apply the new SeNPs fertilizer transformed by us
Stage2：Stakeholder Survey and Interview; Solution Design
④Interviewes with farmers in selenium-deficient areas to understand their intention to apply the new SeNPs fertilizer transformed by us
We went to some selenium-deficient areas around Xinzhou and Nanjing. We interviewed some villagers with their consent by relevant local institutions and parties concerned. We gave them a brief introduction to the new SeNPs fertilizer, its production methods and effects, and tried to understand whether they were willing to use the fertilizer, and what concerns they had about it.
Although many farmers did not fully understand how SeNPs is produced, they said they are willing to try it as long as the fertilizer is effective and the price is acceptable. They are also willing to do their part for global health and the earth's environment.
These interviews let us know that users are concerned about the cost of products, which strengthened our idea of choosing wastewater, as it is easier to obtain as raw material.
Fig.19&20 Interviews with farmers in selenium-deficient areas
⑤An online meeting to consult the Majiang enterprise personnel
Stage2：Stakeholder Survey and Interview; Solution Design
⑤An online meeting to consult the Majiang enterprise personnel
Due to the impact of the COVID-19 epidemic in Nanjing，we contacted with selenium-rich products manufacturing enterprises in Majiang for an online meeting and consulted technical personnel of local enterprises. In terms of cost and efficiency of nano selenium fertilizer to understand the current situation of selenium products and selenium fertilizer, so as to further explore the feasibility and industrialization of our application.
They pointed out that if can break through the existing production restrictions, nano selenium fertilizer will have great market prospects, such as Chinese research experienced selenium valley science and technology team has developed the most emerging biological nutrition strengthening technology: namely using nano technology and targeted guidance technology, the original stubborn selenium ore after further processing which was added to the fertilizer and finally it is absorbed by plants.This selenium-rich technology contains a selenium content of 120 mg / kg, four times that of ordinary rice, and more than 85% of organic selenium.At the same time, Feng technician who participated in the planting of Majiang zinc and selenium rice mentioned that the new nano-selenium fertilizer will help improve the yield and quality of the local selenium-rich crops in Majiang, and expressed their expectations for our project.
This inspired us: nano selenium fertilizer is different from the traditional 'selenium' technology, because it can effectively improve soil selenium content.After crop root absorption, it will be translated into organic selenium. Finally through the root-stem-leaf-grain path, the selenium will get into the crop . The way not only has the advantage that effectively improves of plant selenium content but also is more safe.This interview provides valuable opinion and help guidance for us in exploring the practical significance of the project.
Later, we found that the Institute of Chinese Academy of Sciences broke through the key technology and developed the first nano-selenium fertilizer on the market, which was welcomed by the market due to its high efficiency and low cost. Thus If our project goes well, in the future, we will also continue to explore better production way of nanoselenium leaf fertilizer.
Besides，Majiang is rich in blueberries, and it has been documented that spraying foliar SeNPs fertilizer before picking blueberries can prolong their freshness. People in charge of industry there were interested in whether we can apply SeNPs to blueberries to prolong their shelflife and then transport them to farther areas.They discussed with us the feasibility of this product and expressed a strong desire to use our product at the meeting. This opened up the market for commercialization of our project and confirmed the great value of nano selenium fertilizer.
Fig.19 We interview Majiang enterprise executives (bottom left) and technicians at the research base (top right) online
Fig.20 The technical staff of Majiang Research Base affirmed our project and hope we will personally go to Majiang himself for investigation
Stage3 Solve problems; Experiments and models to validate our project
①Consultation with Professor Zeng Taotao to choose the source of processing materials
Stage3：Solve problems; Experiments and
models to validate our project
①Consultation with Professor Zeng Taotao to choose the source of processing materials
Before the experiment, we first consulted Professor Zeng Taotao via email about the matters for attention and feasibility of extracting selenium from sewage, so as to establish a theoretical basis for the operation of experiments.
Fig.21 Photo of Professor Zeng Taotao
Professor Zeng taotao's main research direction is sewage biological treatment and resource recovery technology. His recent research focuses on bio-extraction of selenium from wastewater, and recovery and production of SeNPs. After reading our email, Professor Zeng explained to us the factors affecting the survival rate of engineering bacteria in wastewater, which initially confirmed our idea and encouraged us to conduct experimental verification in wastewater.
Fig.22 Our email exchange with Professor Zeng Taotao
②In the process of experiments, we usually hold meetings and exchanges with iDEC team members. The exchange of ideas between the two teams and the solutions jointly discussed help the experiments proceed smoothly
Stage3：Solve problems; Experiments and
models to validate our project
②In the process of experiments, we usually hold meetings and exchanges with iDEC team members. The exchange of ideas between the two teams and the solutions jointly discussed help the experiments proceed smoothly
Fig.23 Routine meetings of the iGEM and iDEC team members
③An interview with Dr. Huang Shengwei to help the wet team determine the concentration of the original salt solution
Stage3：Solve problems; Experiments and
models to validate our project
③An interview with Dr. Huang Shengwei to help the wet team determine the concentration of the original salt solution
Before the experiment of SeNPs reduction, we consulted Dr. Huang Shengwei about the setting of solute concentration gradient in solution. He has some research achievements in the reduction of selenate and selenite to SeNPs. Following the suggestion from him, we finally chose to set selenate and selenite with different concentration gradients for pre-experiment, so as to ensure the strongest reduction effect.
Dr.Huang Shengwei
Master Dr. of Can Mechanical Institute
Research Unit: Institute of Intelligent Machinery
A strain of bacteria, Providencia Rettgeri HF16, was isolated with super resistance to sodium
selenite. The study not only enriched the microbial synthesis mechanism of SeNPs, but also provided a new production strain for the industrial production and application of SeNPs.
Fig.24 Email to Dr. Huang Shengwei
Fig.25 Dr. Huang Shengwei’s reply to our email
④Experiments on the effects of SeNPs on plant growth: The important effects of SeNPs on plant growth were confirmed
Stage3：Solve problems; Experiments and
models to validate our project
④Experiments on the effects of SeNPs on plant growth: The important effects of SeNPs on plant growth were confirmed
After we successfully reduced the obtained SeNPs, we conducted preliminary plant experiments to verify its function. In the experiment, we selected 0.5g/L, 1.0g/L, 2.0g/L concentration gradient of SeNPs solution for hydroponic experiment, and finally found that 0.5g/L SeNPs solution has a significant promoting effect on plant growth, and is beneficial to improve the selenium content of plants. This plant demonstration perfectly demonstrates the importance of SeNPs and proves the significance of our project in practical application.
Fig.26 Experiments analysis which confirmed the important effects of SeNPs on plant growth
Summary and future study
Summary and future study
The above research and consultation helped improve the application of our project, making the whole project more meaningful and feasible.
There is no shortage of selenium resources in China, but due to the great regional differences in the distribution of selenium resources, selenium existing in soil can not be directly absorbed by plants, which has set a low technical threshold for the development of selenium industry.
Thus in the future, we hope to reasonably complete the conversion and recycling of selenium through better methods, such as eliminating the interference of other elements through pre-chemical methods, and recovering selenium from polluted or excessive areas more efficiently. We would further reform our reduction system, improve the reduction efficiency, broaden the access channel of selenium, reduce costs and maximize its profit.
SeNPs products have diverse and broad application prospects, including antioxidant activity and anticancer activity in areas of health, and photoelectric performance, semiconductor performance, antibacterial coating and other properties and applications in material industry. In environmental remediation, SeNPs products can adsorb and precipitate heavy metal ions such as mercury ions to reduce toxicity. Especially in the field of food and nutrition, SeNPs can be used in new selenium fertilizers, which is healthier and safer than traditional selenite fertilizers.
With the rapid development of global economy at the cost of the destruction of resources and environment, food safety, which is directly related to human nutrition and health, has become more important. Selenium-rich agricultural products produced with selenium-rich fertilizers have the functions of anti-oxidation, anti-aging, anti-virus, enhancing immunity, and antagonizing heavy metals, among which the function of enhancing immunity has attracted special attention due to the impact of COVID-19.
Selenium is closely related to people, animals and the environment, and the significance of the project is mainly to help the uneven distribution of selenium around the world, and contribute to the transformation of nutrition structure under the contradiction between the green revolution and food security.
We believe that SeNPs will have more space to present its unique advantages.