Team:NPU-CHINA/Human Practices
Integrated
Human Practice
This year, our team mainly focuses on solving the problem of aflatoxin pollution. As a Class I carcinoid substance recognized by WHO, aflatoxin causes great economic losses to various feed enterprises every year because of its extremely low degradability and common in grain feedery .Through consulting relevant information in the early stage, we found a degradation enzyme that can be used to degrade aflatoxin, which made us see the feasibility of aflatoxin degradation.Then we had an interview with different animal husbandry production of practitioners, through the communication with them, we learn about the production process and principle of the feed. This experience provided us some theory support in the process of project design.We also exchanged views with professionals from universities and government departments, covering different fields such as biology, environment and ecology, and mathematics. At the same time, we kept close contact with teams from other universities and shared a lot of valuable information. In order to integrate our project into the society and promote the ideas and methods of synthetic biology, we distributed questionnaires related to this topic through online channels and carried out teaching activities related to synthetic biology. In the process of all the activities mentioned above, we take security as our values and basic requirements, and ensure the information security of participants according to the guidance of professionals.
In the whole research activities, every step of our activities complement each other, thus forming an organic whole
During HP activities, we were very focused on convert other people's suggestions into designs for our themes, thus creating a closed loop between other people's expectations and our designs. As shown in the figure below.
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Thinking and investigation
Aflatoxin is classified as a Class 1 carcinogen by the Cancer Research agency of the World Health Organization (WHO) and is highly toxic.Aflatoxin is destructive to human and animal liver tissue and can lead to liver cancer and even death in severe cases.The biggest headache is that aflatoxin is hard to break down and can accumulate in meat and dairy products.When people consume dairy products or meat containing aflatoxin, the accumulation of aflatoxin in the body may become a risk of liver cancer and other cancers.At present, the main feed material used in livestock products is corn, the most common crop with aflatoxin contamination.In the production of animal husbandry products, aflatoxin will be absorbed by animals in meat, eggs and milk products, and then enter the human body.
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Ranch interview
To understand the problem of aflatoxin pollution in real production, we visited Mr. Gan, a self-employed farmer.
Mr. Gan explained that the energy component of their pasture feed is currently corn.Corn is a very important feed material in pasture raising.The full-price feed is purchased using a byproduct of the corn industry, such as corn or bran.Both concentrate and premix are added by farmers themselves.Among them, aflatoxin produced by corn mildew has become a very serious problem.It is clear that present aflatoxin pollution is the stumbling block in animal husbandry production.
Mr. Gan also told us about a food poisoning case that happened in 2020. Food poisoning is caused when a family eats food that has been sitting for a long time and many people died. Throughout the investigation, aflatoxin was identified as the toxin most likely to have caused the death. Until the case was over, fears of aflatoxin poisoning hung over the public. Aflatoxin has always been a major hidden danger causing food safety problems.
The picture is of Mr. Gan
We also interviewed Mr. Shang Wenkai, the head of Longjia Animal Husbandry. Mr. Shang introduced that the price of dairy products is usually based on quality. Every month, dairy products will have a basic standard and corresponding basic price, and dairy products will get extra profits if they exceed the standard.The additional profits from lower aflatoxin levels are significant.Usually feed will achieve as much as possible within 3 days to complete a turnover.In addition to the day of feed testing, for have to store more than 15 days of feed should also be carefully
Tested.
The picture shows Mr. Shang Wenkai
It seems that aflatoxin content is not only the most basic guarantee of products, but also an indicator to bring profits.If we can solve the problem of aflatoxin in corn, it will not only bring huge economic benefits for agricultural products market, but also create inestimable social benefits.This not only solves the problem that aflatoxin cannot be eliminated from feed, but also fundamentally improves the quality of animal husbandry products and improves people's food safety standards. If synthetic biology is used to solve the problem, it can also bring great opportunities for environmental protection and sustainable development of the industry.Through investigation, we decided to solve the problem of aflatoxin contamination in feed.
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Understand consumers' wishes
According to the problems our project is to solve, we issued a questionnaire to investigate the social reaction to our project.Our questionnaire covers basic information collection, understanding of carcinogens and anticancer elements, and suggestions for solving problems in synthetic biology.We collected 139 questionnaires, mainly from consumers.Now, we select part of the survey results for display.
Q1:What is your age
Q2:The industry you are currently engaged in is
As can be seen from the above survey results, most of our survey groups are between 18 and 30 years old and cover other age groups.We predict that the results of this survey can mainly reflect the understanding of young and middle-aged people about aflatoxin, selenium and biosafety.The survey also covered a wide range of industries.Among them, those engaged in or studying life science/materials/pharmaceutical are the main survey group.
Q3:How much do you know aflatoxin
The graph shows what you know about aflatoxin.
The higher the number, the more you know about aflatoxinAfter our investigation, the people do not understand or do not understand aflatoxin harm slightly more.This shows that people pay attention to their own diet health and food safety problems, but do not have a detailed understanding of the various hidden dangers of food safety.In the preliminary planning of the questionnaire, we considered that people might not know much about it, so we put "knowledge cards" under the corresponding topics for popular science while conducting the questionnaire survey.In the investigation at the same time also let the respondent can gain.Our questionnaire has been well evaluated during the survey.
Q4:Are you concerned about biosafety (environment, food, etc.)
Q5:How do you get information about biosafety
We also investigated biosafety-related issues, and it can be seen from the biosafety-related investigations that the public generally pays high attention to biosafety issues.In addition, the survey group has a wide range of channels to understand biosafety-related information, mainly from network news media, followed by short video software.It is easy to see that people are very concerned about biosafety and other issues, and tend to use the media in daily life to learn about relevant information.
It is not difficult to find through the survey of consumers that most consumers care about biosafety and food safety very much.This is also our team design and experiment in the first place, is our core values.
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Project Determination
In order to further understand the current difficulties of aflatoxin and our possible breakthrough points, we contacted Mr. Cui Wei, general manager of Yangling Tiandi Big Animal Nutrition Technology Co., LTD., Tianxi Village, Yangling District, Xianyang City, Shaanxi Province.
Mr. Cui on the left and Prof. Niu on the right
Mr. Cui said that aflatoxins in animal husbandry mainly come from grain feed, especially corn.Corn crops harvested in the fall are vulnerable to wet weather at harvest time, resulting in lower quality.The main reason of aflatoxin production is water.Storage corn usually requires a water content of no more than 14 percent, while harvested corn is usually 20 percent or more water.If not dried in time or stored for a long time, this can lead to mold growth in grains such as corn that produce high levels of aflatoxin.At present, agricultural feed companies mainly mix corn with low aflatoxin content and high aflatoxin content in proportion to achieve relevant standards.In addition, the feed company also through the absorption of aflatoxin auxiliary methods to improve feed quality, but the effect is not satisfactory.
The picture shows Mr. Cui Wei
Aflatoxin can not be degraded in animal feed.At present, the common method is to mix corn with low aflatoxin content and high aflatoxin content in proportion, so that the mixed corn product is lower than the relevant standard before adding.At present, there is an urgent need for additives or other types of products that can radically reduce the content of aflatoxin in both pasture and feed mills.This will create great economic and social value.
The picture shows NPU-CHINA team in Yangling Tiandi Big
Animal Nutrition Science and Technology Co., LTDFinally, we discussed with Mr. Cui which process is more likely to achieve degradation of aflatoxin by introducing aflatoxin treatment method.Mr. Cui pointed out that at present the most feasible is the use of preparation, in the feed fully mixed, before pelleting, packaging introduction of preparation for treatment is more feasible.After discussing with Mr. Cui, we decided to make preparation products to solve the problem of aflatoxin pollution.
What we learn：We known that our current project needs to produce a preparation product.
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Project Design
1 Determination of experimental methods
In order to understand the feasibility and possible solutions of aflatoxin degradation in feed, we visited Professor Niu Weining from the School of Life Sciences at Northwestern Polytechnical University.
After understanding our initial social needs, Prof. Niu proposed that we can use genetically engineered strains to achieve degradation, and the most feasible method is to use synthetic biology to synthesize corresponding degradation enzymes to achieve degradation.The use of physical adsorption or chemical methods may introduce more treatment procedures, resulting in high treatment cost or low treatment efficiency, unsatisfactory effect, or even the introduction of new harmful substances that are difficult to remove in the treatment of aflatoxin.
After our communication with Prof. Niu and Mr. Cui, general manager of Yangling Tiandi Animal Nutrition Science and Technology Co., LTD.We agree that the use of a prokaryotic expression system (Bacillus subtilis) as the chassis cell is most appropriate.On the one hand, the prokaryotic expression system is relatively simple, and is easily modified and controlled due to thorough research at present.Bacillus subtilis, on the other hand, is a probiotic in animal husbandry and is safer to handle for both experimenters and end-product users.
The use of safe engineered bacteria can not only avoid unnecessary problems introduced in the process of treatment but also achieve efficient degradation, which is very worthy of consideration.Prof. Niu also pointed out that the selection of suitable engineered bacteria will significantly improve the performance of the final product.
What we learn：We learned that we had better choose prokaryotic expression systems to synthesize degradation enzymes to degrade aflatoxin.
2 Strain selection
After aflatoxin treatment with prokaryotic system expressing aflatoxin degrading enzyme was determined.To learn more about which safe strains to use, we called on Professor Shi Junling, school of Life Sciences, Northwestern Polytechnical University.We present our preliminary proposal for the degradation of aflatoxin and the possible suitable strains we have investigated, in the hope of knowing which strains of engineered bacteria are most suitable for animal feed.
After understanding our ideas and the strains we investigated, Prof. Shi believed that Bacillus subtilis had the foundation to become the engineering bacteria of our project.Prof. Shi pointed out that Bacillus subtilis is used for sewage, garbage, waste treatment;Animal husbandry and poultry breeding;It can be mixed with many kinds of bacteria and plays an important role in agricultural production.It can also aid digestion and is a probiotic in the digestive tract.It is an ideal engineering bacterium for aflatoxin degradation in feed.Finally, Prof. Shi introduced the particularity of the expression system of Bacillus subtilis, which could not be studied using some commonly used plasmids and media.
What we learn：We learned that Bacillus subtilis is our ideal engineering bacterium.
3 Environment of strain action
We identified the use of Bacillus subtilis as our cell carrier.According to the scheme of our project, the intestinal tract of animals may become the site of aflatoxin degradation reaction, so whether the intestinal environment affects the function of engineered bacteria is crucial.We asked Shang Xiaoya, a professor at northwestern Polytechnical University's School of Life sciences.
Professor Shang introduced to us the basic environment in the animal intestine and some common good bacteria and harmful bacteria.There are also probiotics and harmful bacteria on the way of intestinal impact and performance.Bacillus subtilis is also a safe probiotics.At the same time, Professor Shang also introduced the current food safety related departments to detect food safety related methods.Professor Shang affirmed the safety and rationality of using Bacillus subtilis as an additive in animal feed.Finally professor Shang also introduced the cultivation requirements and growth characteristics of Bacillus subtilis.
What we learn：We know the characteristics of Bacillus subtilis and some considerations for culture and element selection.
4 Release of degrading enzymes
Identify with bacillus subtilis as the engineering bacteria and knowledge of the environment of the bacillus subtilis role, we also want to know about its expression as a secreted protein degradation enzyme release efficiency, whether the bacillus subtilis normal expression can aflatoxin degradation enzyme, we visited the school of northwestern polytechnical university life Li Aipeng teacher.
Mr. Li is engaged in research related to synthetic biology.He suggested that if we needed to get Bacillus subtilis to release aflatoxin degrading enzymes normally, we could design a self-lysis system.In bacillus subtilis growth synthesis of aflatoxin degradation enzyme at the most vigorous time to start the autolysis system, so that the bacteria lysis, release no secretion of aflatoxin degradation enzyme.Teacher Li gave us a great inspiration, we can think about whether the efficient release of aflatoxin degradation enzyme when we might as well change the idea -- break the cell, with the most direct way to release aflatoxin.
What we learn：We learned that we could introduce a self-lysis system to achieve the release of degrading enzymes.
5 nano-selenium synthesis
At the time of our research, Cui also noted that selenium is currently commonly added to animal feed in the form of sodium selenite.However, sodium selenite is highly toxic, harmful to animals and has a certain impact on product quality.If organic selenium or nano-selenium can be used as additives, it may not only supplement trace elements to animals, but also be enriched in products to improve the nutritional value of products.Therefore, in addition to the synthesis and degradation of aflatoxin, our project also considers the synthesis of nano-selenium.
Compared with sodium selenite, which is toxic, nano-selenium is not only easy to absorb but also not toxic, making it safer as a feed additive.
We asked Xu Chunlan, a professor at northwestern Polytechnical University's School of Life sciences.After understanding the requirements of our project, Professor Xu pointed out that Bacillus subtilis WB600 has its own se-rich system for the synthesis of nano-selenium.We can directly use Bacillus subtilis to synthesize nano-selenium, which greatly reduces the workload of designing se-rich systems.It also confirmed the feasibility of selecting Bacillus subtilis as engineering bacteria.
What we learn：We learned that we can also achieve the synthesis of nano-selenium using Bacillus subtilis.This allows us to implement additional functionality.
6 Experimental safety and aflatoxin detection
Finally, we also need to understand the security issues of our project.
We asked Huang Qingsheng, a professor at northwestern Polytechnical University's School of Life sciences.Professor Huang has been engaged in microbiology-related research for many years and has a good understanding of microbial safety and other issues.
After understanding our project background, project scheme and the engineering bacteria we selected, Professor Huang proposed that the engineering bacteria we selected were relatively common engineering strains and it was relatively safe to conduct relevant experiments.
Huang also pointed out that there are several methods to detect aflatoxin, and all of them are mature.In our experiments, it is relatively convenient to carry out aflatoxin related detection, which can be carried out simply and quickly.
What we learn：We learned that our program was very safe and that testing was easy to implement.
7 Investigate the feasibility
After the functions and implementation methods of the whole system are determined, whether the system is feasible is the last problem to be solved before we carry out experiments.We asked Xu Ming, a professor at Inner Mongolia Agricultural University and a consultant for a large dairy company in China, about the feasibility of building the whole system.Our system consists of three parts: aflatoxin degradation enzyme synthesis system, bacillus subtilis autolysis system and selenium enrichment system.All three parts of our system specify which biological components to use.professor Xu Ming gave a positive answer after understanding our project design in detail.
Finally, we learned that our project could be realized.
The picture shows Professor Xu Ming
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Northwest Regional Exchange Meeting
Due to the COVID-19 pandemic, this year's NORTHWEST Region Communication Conference was held in an online and offline combination format.Npu-china, NWU-China-A, NWu-China-B, XJTU-China, LZU-China, DUT-China participated in this northwest region exchange meeting.Among them, LZU-China and Dut-China introduced their projects through videos on social media.
In addition, former iGEM leaders Cheng Yuhan, Zhang Yu, Xu Mengmeng participated in the meeting, and Chen Jionglin, secretary General of CCiC executive Committee attended and delivered a speech online.During the meeting, we had a detailed understanding of the subject content of other teams and put forward many beneficial suggestions to improve each other's subject design.
Each team presented their own project from the aspects of project introduction, experimental design and future vision, and discussed the advantages and disadvantages and doubts of the project with other teams.
In the final free discussion, we could exchange our experience and learn from each other.This Northwest Region exchange conference laid a foundation for us to contact and cooperate with other teams.
Northwest Region exchange conference group photo
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CCIC
CCiC is short for iGEM Community Congress in China.
Affected by the epidemic, the 8th CCiC was held online and offline.
From August 27 to 28, we participated in the conference through web conference and video presentation.
While introducing our project, we also kept in touch with other teams and gained valuable opinions while making suggestions.These suggestions played an important role when we carried out specific experiments.
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Define values again
In the process of project advancement and improvement, we always put safety first.The vision of our project is to scale up the use of synthetic biological methods to degrade aflatoxin in feed.Once the new method is used on a large scale, any slight safety hazard can become a serious public safety problem.Therefore, the need for security is a top priority in our project.This is reflected in our early selection of engineering bacteria and experimental operation specifications, and in the questionnaire distributed to the public, we specifically asked the public about their understanding and acceptance of biosafety.
In the implementation of the project, we hope to protect the interests of manufacturers and consumer groups to the greatest extent.This can be fully reflected in our design: we have adopted the advice of livestock practitioners.After we conducted a consumer survey, we received positive and expectant responses from the public, thus reinforcing our previous idea.
Finally, because our project uses proven techniques and bacillus subtilis, it does not directly edit the genes of plants and animals, so it does not introduce ethical issues.
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Feedback Survey
After shaping our project, we really want to know what consumers, the biggest beneficiaries of food safety, thought about our project.To that end, we surveyed consumer acceptance of biosafety and our program.
Q6:Would you like to see more products using synthetic biology (using biological fermentation or genetic manipulation to quickly get the most ideal, efficient and environmentally friendly production methods) to solve the problems in production and life
The graph shows expectations. The higher the number, the higher the expectation
Q7:Would you accept the use of synthetic biology (the use of biological fermentation or genetic manipulation to quickly achieve the best, most efficient and environmentally friendly production methods) to solve food safety problems
The graph shows acceptability values. The higher the number, the higher the acceptability
Q8:Would you prefer to buy or choose foods that are processed using synthetic biology (using biological fermentation or genetic manipulation to quickly produce the most desirable, efficient and environmentally friendly production methods)
The graph shows expectations. The higher the number, the higher the expectation
From the survey results of the above three questions, it is not difficult to see that the public supports the use of synthetic biology and other methods to solve problems in life.Most people expect us to use synthetic biology to change people's lives.Synthetic biological approaches to food processing have high support among researchers.There is also acceptance that synthetic biology offers new ideas for food safety.This investigation has greatly encouraged us to use synthetic biological approaches to solve the problem of aflatoxin in feed.
In addition, we also conducted a survey on the public's recognition of our project.
Q9:According to our preliminary investigation, China's livestock and poultry feed is polluted by aflatoxin, harmful to animal and human health.We designed a kind of feed additive with two effects of degradation of carcinogen aflatoxin and enrichment of anticancer element selenium by using synthetic biology method.Do you support our research project
Q10:What do you value about our biologically-processed meat, eggs and milk products
As these two questions show, it is not just the general public that has great interest in synthetic biology changing lives.The public also has high expectations for our project.Most of the respondents have high concerns about the safety of our project products.According to our preliminary work, we are sure that we can meet the major needs of the public for our project.After understanding the needs of livestock producers, we received strong support from the public for our project.
After a series of research and feedback to our project, we successfully solved the problem of aflatoxin degradation in our project.
Feedback The Problem：
We surveyed livestock practitioners by proposing solutions to the aflatoxin problem. After investigating the ranch, we found that there was a safety risk of aflatoxin contamination. So we decided that society needed us to solve this problem. Next, we conducted a survey of consumers. The final result of the survey shows that consumers attach great importance to food safety and want us to solve relevant problems. After knowing that our question has high economic and social value through investigation, we determined the research question. After identifying the research problem, we visited the feed manufacturer and Professor Niu. Finally, we decided to use the prokaryotic expression system to secrete aflatoxin degrading enzymes as our means of processing aflatoxin. Then, we identified bacillus subtilis as an engineering bacterium and understood the characteristics of Bacillus subtilis. As for the release of aflatoxin degrading enzyme, Instructor Li provided us with a brand new idea -- introduction of autolysis system. In addition, we were surprised to find that Bacillus subtilis has a nano-selenium synthesis system. We therefore introduce the function of nano-selenium synthesis.
Finally, we consulted Professor Huang and Professor Xu on safety and feasibility. All received positive responses.
Through continuous research, we gradually built up our project plan. In the Northwest Regional Conference and CCiC conference, we actively communicated and cooperated with other teams.
Finally, we did a feedback survey again. We know that consumers are very supportive of our program. After getting the customer's approval, we managed to make our design feedback to the problem we were trying to solve.
CONTACT NPU CHINA
NPU-CHINA is the iGEM team of Northwestern Polytechnical University
Address: 127 West Youyi Road Beilin District, Xi'an,
Shaanxi 710072, China
Contact: npuigem@outlook.com
bilibili: NPU-iGEM
