Mycotoxin aflatoxin B1 (AFB1) is one of the most potent rodent and human liver carcinogens, according to World Health Organization (WHO) and International Agency for Research on Cancer (IARC).
If humans accidentally consume peanuts, corn, or crops containing aflatoxin, the chances of getting liver cancer would tremendously increase. Therefore it is essential to avoid eating anything that could contain aflatoxin, especially expired food or food stored in extremely humid or hot environments.
In Taiwan, liver-related diseases are prevalent. Also, aflatoxin is one of the most potent human liver carcinogens. During Integrated Human Practice, we also found out that aflatoxin causes great damage in animal husbandry.
The animal feed often contains aflatoxin due to the humid and warm environment, contaminated commodities are often fed to animals. If humans eat animals that consumed animal feed containing aflatoxin, animal tests show that it would increase the likelihood of humans getting liver cancer.
Currently there isn’t a complete nor easy way to prevent animal feed from being contaminated with aflatoxin. This is a major food safety problem.
We set out to develop an antidote that could degrade aflatoxin in the gastrointestinal tract and help our bodies get rid of it, preventing aflatoxin from entering our blood flow system.
Using the antidote as a food additives could help the animal husbandry business solve the animal feed safety problem they are facing.
In order to develop an antidote that degrades aflatoxin in the gastrointestinal tract, iGEM CSMU_NCHU_Taiwan found an enzyme called MSMEG5998 (a F420-dependent reductase group A (FDR-A)) and the gene sequencing, which could degrade aflatoxin. Also we worked intensely with Dr. Matthew Taylor, who works for CISRO, Australia, gaining valuable advice and assistance.
Our team made a recombinant DNA and sent it into yeast, which would become the MSMEG5998-producing factory. Additionally, we designed Thioredoxin fusion protein to assist enzyme folding that increases efficiency and productivity. Due to safety concerns we picked yeast. The merits are that the recombinant DNA techniques of yeast has become more mature, and yeast is considered safe and common in foods.
Our key technique is that the gene sequence must be overexpressed and produces protein, in the meantime, we have to prevent the proteins from becoming inclusion bodies, because inclusion bodies would affect the enzyme activity tremendously.
The capsule of the antidote would also made of genetically modified yeast. It is designed this way so that the enzyme would be released in the gastrointestinal tract, degrading aflatoxin in intestines or liver through the circulatory system, preventing chronic intoxication.
We named our antidote “Aflatoxout”, implying that we want Aflatoxin out of our bodies. If livestock eat Aflatoxout, the enzymes would degrade aflatoxin in their gastrointestinal tracts, eliminating these toxins that may cause harm to the livestock as well as humans that consume these livestock.
Since we are developing something that no one has ever created before, we have to discuss with food safety professionals and animal husbandry professionals to see if our product is really what people need and something they would consider buying it. We set some goals when we met with professionals:
- Introduce our Project
- Learn from their expertise and use that knowledge to further develop our project
- Make contacts for potential future collaborations
We started to meet with several professionals from different fields like doctors, feed companies, farmers, drug factories and so on. They all gave Aflatoxout great feedbacks and said that Aflatoxout may become the most efficient way to keep aflatoxin away from living beings. We were strongly motivated after these numerous meetings.
Then, we came to visit food safety expert, Dr. Kun-Yu Wu. Dr. Wu suggested that we pivot our goal from human treatment to animal treatment because it is an easier start due to limitations in law regulation and techniques. And if our product works, it could decrease the chances of accumulating aflatoxin in human bodies from the origin- foods.
After the discussion, we knew how to adjust our project properly and realized that people really need Aflatoxout. Since liver illness has been popular in Taiwan for decades, we believe if we could minimize the animal consumption of aflatoxin, we could really make a difference in Taiwan and China, where people also suffered from liver illness.
Poultry Association Republic of China
Poultry Association Republic of China is a Taiwanese NPO that unites the chicken farmers throughout Taiwan. We met with the secretary-general of the organization, Dr. Jian-Pei Wang. During the conversation, we found several interesting facts.
In the chicken farming industry, chicken feed contributes 60-70% of their cost. Therefore the Feed Conversion Rate (FCR) is essential in the chicken feeding business. (1.5Feed Conversion Rate=3kg of chicken feed/2kg of chicken weight). Though chickens have high resistance to aflatoxin, they would still vomit or decrease in appetite after consuming aflatoxin. Therefore, if the FCR increases from 1.5 to 1.6, the cost of every kilogram of chicken feed would increase 10 US cents. It can make a huge difference for chicken farmers. Thus, high quality chicken feed has always been chicken farmers’ top concern.
Taiwan has several animal feed companies such as Charoen Pokphand Enterprise (iGEM CSMU_NCHU_Taiwan also met with them). The majority of their feed are imported from overseas, so the logistics easily makes the feed likely to grow aflatoxin. When chicken farmers find brands of feed with low FCR, they usually directly change to another brand, because they do not want to spend time waiting for the test results.
At the end of the conversation, Dr. Jian-Pei Wang encouraged us to keep developing Aflatoxout. He said if it work out well in chicken, then the chicken farming industries would definitely welcome our product Aflatoxout!
King of Black Swine
King of Black Swine is one of the biggest pig farming company in Taiwan. We met with the CEO of the company, Mr. Wen-Tung Wang.
During the conversation, Mr. Wang shared his experience and expertise with us. “Aflatoxin has huge influences on white pigs, and it made the white pigs hard to reproduce if it consume certain amount of aflatoxin,” he said.
Nowadays, the feed additives for aflatoxin are usually not effective because pigs lose its appetite. Our product Aflatoxout is actually made of yeast. Therefore, it supposedly would not taste that bad. “If it also degrade the aflatoxin in pig’s gastrointestinal tract, it would be a promising feed additives for pig farming industries,” Dr. Wang said.
Milk House Co
Milk House Co. is a milk-producing startup in Taiwan. It made a sensation and now have their milk supplying in the biggest convenience stores in Taiwan and Japan, FamilyMart. We had an opportunity to talk with the CEO of this company, Dr. Chien-Chia Kung, who is also a licensed vet.
During the conversation, he told us that there are currently no regulations on cow feed. However, aflatoxin can adversely affect cow’s health and the quality of milk. Therefore he is really optimistic about our product, hoping that cows can eat healthier, consequently consumers also drinking higher quality milk.
Charoen Pokphand Enterprise
Charoen Pokphand Enterprise is the biggest animal feed company in Taiwan and Asia. We were fortunate enough to talk to the Dr. Kun-You Lin, the Associate General Manager of the Taiwan branch of the Charoen Pokphand Enterprise. Since it is the biggest animal feed supplier in Asia, they have become one of our potential future customer.
“In the current anti-myotoxin additives, yeast cells has been used for long time. If you could successfully use genetically-engineering techniques to make yeast produce enzymes that degrade aflatoxin, our customer would definitely give your Aflatoxout a try.” Dr. Lin said. He also said they would collaborate with us if Aflatoxout could significantly degrade aflatoxin in animal’s gastrointestinal tract. This really prove that Aflatoxout could be a great product for animal feed market.
As mentioned, most companies pretty care about the influence caused by aflatoxin and have some methods to reduce the financial loss. Below are the current solutions that companies in Taiwan use for aflatoxin prevention. (And we take pigs for instance)
- Mixing dilution technique
- Chemical detoxifying technique
- Mycotoxin adsorbents
Since the regulation standard for the concentration of aflatoxin in pig feed is below 50 ppb, animal feed companies would mix the high concentration feed with the low concentration ones to pass the regulation. However, this still does not change the fact that livestocks will take in the polluted feed.
It could preserve the feed longer by eliminating mycotoxins. However, pig are disgusted by the taste, so the Feed Conversion Rate of the livestock is lower than the ones that do not use this method.
Silicate minerals, activated charcoal, polymers and chlorophyll products adsorb aflatoxin, so that the toxin would not be absorbed in the intestines. A drawback is that it would also absorb the nutrients that the livestock take in, which means a large amount of feed is required to maintain nutrition for the pigs. Plus, pigs reject the taste so the feed would not be cost-effective.
The advantages of “Aflatoxout”
After pigs take in the Aflatoxout, the yeast will release the enzyme that could degrade aflatoxin. It is a fundamental way to decrease the amount of aflatoxin in the pigs that tackles with the source of the problem. Besides, Aflatoxout is made of yeast so pig would not reject the taste since yeast is already a common ingredient in swine feed. We will be able to lower the costs through synthetic biology methods, effectively producing large amounts of this enzyme.
- 1. WHO estimates of the global burden of foodborne diseases Foodborne diseases burden epidemiology reference group 2007-2015: p. 108-109
- 2. Council of Agriculture Executive Yuan R.O.C. (Taiwan), Principles, practices, Hazard analysis and critical control point (HACCP) for prevention and control of mycotoxins, and Laboratory detection of mycotoxins in feeds, p. 34-36