Part 1: Envision and Implementation of Our Project

Preservation of engineered bacteria

    During our experiments, we have proved that lyophilization can produce the dried power of engineered bacteria. Therefore, by adding our TDPs, the bacteria could be successfully resuscitated to function. Additionally, the survival rate of bacteria was higher than the control group as well.
    Our results showed that after lyophilization and being stored at room temperature for over 10 days, the bacteria was still alive. Hence, this means that through our storage method, the room temperature storage of bacteria has become a reality so that the practical application of bacteria can be more easily achieved.
    Thus, for iGEM teams, if their bacteria need to be used under room temperature, we can help them produce the products they want. Moreover, if the storage equipment in their laboratory experience mechanical breakdowns, they can use lyophilization to store their bacteria immediately to avoid the bacteria from losing its functions or going bad.
    For example, We can help the bacteria to attain its daily usage for patients. Take QHFZ-China 2019’s project as an example, their bacteria which have the ability to detect uric acid can be made into a dry powder through utilization of lyophilization. Afterwards, if the patients or normal people want to detect the level of uric acid in their bodies, they can buy the bacteria and store them in their home without the use of ultralow-temperature equipments so that it makes the process convenient to all people.

Left top: 8 out of 10 teams thought with our project, their engineered bacteria would be closer to practical application (score 4 or 5). Left bottom: With bacteria powder, we designed a uric acid detection kit, which can be stored without ultra-low temperature freezers, so that the imagination of Tean QHFZ-China 2019 came ture. Right: Via our project, we gave Team NEFU-China 2020 a strategy to improve their project.

Bacterial Transportation

    From an interview with Sierra Leonean entrepreneur Miatta Momoh, we understood that there are very few cold chains energy systems in Sierra Leone, so it is hard to use and transport engineered bacteria. However, our project will help replace the cold chain system to better protect biological products, which will be particularly helpful for Sierra Leoneans and everyone else in the world who may utilize biological products. As long as the customers give out demands, we can achieve the mass-production of suitable bacteria dry powder, after produced, the dry powder can be transported through any method of choice without the limitation of time or temperature in normal storage methods. We’ll also give them medium or just the sterilized water at the same time. Afterwards, if the bacteria needs to elaborate its function, the customer only need to add the liquid we provided to the bacteria for it to reach its requirements.
By taking this initiative, the cost of cold chain transportation can be greatly reduced, which also reduces the cost for people who will use these bacteria in the future. It breaks the restrictions of environmental and geographical conditions, allowing a innovative storage method.

Cold chain is lacking, expensive and easy to go wrong. With the help of our project, the bacteria can be transported without it.

Paper-based Biobatteries

    From the sustainable development goal of affordable and clean energy, we realized that our project can form a collaboration with the production of paper-based biobatteries [1]. By freeze-drying the bacteria into paper and other porous substrates, we can create materials with the fundamental transcription and translation properties of a cell. If we want to activate the bacteria, we can simply add water. If we add our TDPs with the bacteria, it can survive better and more bacteria will function efficiently while being used, increasing the effectiveness of fuel cell generation. Hence, the cost of generating electrical power can be abbreviated.

In 2020, a paper-based microbial fuel cell sensor utilizing freeze-dried bacteria came out[1]. The freeze-dried bacteria on paper function as a microbattery and drive a useful device. If TDPs can enhance the survival rate and prolong the shelf life, the microbattery would give a better electric power.

Industrial Usage

    Our project can benefit the production of yeast powder, probiotics, and nitrifying bacteria. According to our human practices work, we understood that the maximum survival rate of existing lyophilization products is 10%, which we believed can be increased. After analyzing our results, we found that the bacteria with TDPs survived better than the control group. Through our experiments, we realized that the TDPs could act as protectants in both BL21 (DE3) and DH5alpha strain.
Therefore, if factories use our method to produce their goods, the survival rate can be guaranteed, the output can be increased,and that the cost of production will be reduced.

There are quite a few dry bacteria products, such as dried yeast, probiotics tablets and nitrobacteria capsule. Our project can enhance the survival rate, so that the factories can use same amount of the microorganism to produce more products. Thus, the cost reduces.

Part 2:Commercialization and Proposed End Users

    While we designed our project, some of our inspirations came from the uric acid detector that we made last year. We found that the engineered bacteria already have many functions nowadays, but most of them can’t be use in our daily lives because we don’t have professional equipments to facilitate their usages. Our project mainly focused on the usage and storage of engineered bacteria. Therefore, our proposed users include the iGEM teams whose bacteria need to be used by normal people, the people who need these bacteria to detect or monitor different activities, and also for the factories who have the need for improved production of yeast powder and so on. For detailed explanation, we’ll determine the suitable TDPs and its expression level for customer based on the requirements that they will give us. From then on, in order to avoid surplus stress that TDPs may cause to the bacteria at the maximum levels, we designed a degradation module. According to the degradation time given by the customer, we’ll finally produce its ideal bacteria dry powder that will basically self-destruct once its job is done. Therefore, based on the explanations above, our team will create a bacteria supplication platform for the public. Our method can achieve mass-produce so that it won’t impact the output and will save large amounts of production time. Additionally, we believe that our design will improve the quality of bacteria products and their functions so that their usages and values be ensured to a great extent.

We focus on the engineered bacteria that are designed to be used out of laboratory, because there is no ultra-low temperature freezers to store it. We will collaborate with the engineered bacteria producers, and finally offer the product to the users. The users are not life science researchers, but common people who need to use certain engineered bacteria.

Part 3: Safety Aspects We Need To Consider

    Though our project provided a new preservation method for the engineered bacteria, we still need to consider the following aspects:
    During the preparation of the bacteria, the lyophilization machines should be used carefully and patiently. We need to make sure that the working process of our machine is functioning normally and the operation should be done based on the safety rules in our lab. Additionally, we need to confirm that the machine does not function individually without a human facilitating it to ensure safety.
    If we offer the bacteria to normal people, we need to make sure that the resuscitation protocol is easy and safe to follow. We will also make sure that this protocol as detailed as possible. When we produce the final product, each tube of the bacteria will be used only one single time, so the disclosure of bacteria which may cause environmental pollutions can be avoided.

Safety Aspects We Need To Consider

Part 4: Other Challenges We Need To Consider

    Nowadays, large blank spaces still remain for the improvements of survival rates of bacteria after lyophilization. Hence, though our TDPs truly displayed their functions during the lyophilization process, we still have a lot of opportunities and options to better improve the survival rates of our bacteria.
    Moreover, the expression of TDPs may affect the original function of engineered bacteria in the long term as they remain in the cell. Therefore, we need to find the best suitable degradation circuit for TDPs.
    Additionally, whether our proteins can be used in fungi needs to be confirmed so that we can determine the application range of our project more clearly.
    Last but not least, when the customers get their bacteria, we need to come up with an idea that can avoid as much leakage of bacteria as possible. If we want to transform our TDPs into yeast or other types of micro-organisms that may relate to foods we eat, the safety requirements and the acceptance rates among the public both need to be considered.

Other Challenges We Need To Consider


[1] Cho, J.H., Gao, Y., Ryu, J., and Choi, S. (2020). Portable, Disposable, Paper-Based Microbial Fuel Cell Sensor Utilizing Freeze-Dried Bacteria for In Situ Water Quality Monitoring. ACS Omega 5, 13940-13947.



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