Team:Qdai/Human Practices
Human Practices
Introduction
Synthetic biology is still a new discipline, and many aspects need to be discussed, such as the scope of its applications, safety issues, and society’s perception of synthetic biology. Therefore, feedback from various standpoints such as users, experts, and production companies is needed.
Since rare metals are currently used in numerous high-end detectors, the purpose of this project is to replace the currently used toxic gas detectors with E. coli-based detectors and, therefore, to make biological gas sensors a new option among sensor methods.
When considering the impact of this project on society, several points should be considered, such as:
Current gas sensor situation
Contribution to resource issues and SDGs
Differentiation from existing gas sensors
Potential market
Dissemination of knowledge on synthetic biology
To deepen our understanding of these points, we interviewed companies that produce gas sensors, visited their facilities, and had discussions with experts.
We found out from these activities that there is a certain demand in the market for the gas sensor planned in this project, and that there is room to introduce it in places where gas sensors are not currently installed.
In addition, the use of living organisms has the advantage of reducing the use of rare metals, which are not currently recycled because they are unprofitable.
However, the gas sensor using living organisms has many problems such as slow reaction speed, low durability to environmental changes, weak signal, and detection capability. We found that it is necessary to differentiate our product from existing products by detecting multiple components simultaneously.
Regarding society’s understanding of synthetic biology, there is currently a strong prejudice against genetic modification in Japan, and low literacy in biology. We recognized there is a need to continue introducing examples of the use of synthetic biology and to spread knowledge about biology in a more understandable way.
Figaro Engineering Inc
We had an online meeting with Figaro Engineering Inc, a company that sells gas sensors, and exchanged opinions on the demand for carbon monoxide sensors and the current state of technology.
Currently, the main market for CO sensors is in the US, where installation of the sensors in households is mandatory and they need to be replaced every five years, hence a stable demand can be expected. In Japan, there is no obligation to install the sensors, so there is not a big market for the time being. However, there are accidents related to toxic gases from charcoal fires, charcoal briquettes, and exhaust gases. Therefore, increasing demand can be expected.
As for the rare metals used in gas sensors, platinum, vanadium, gold, and other metals are used, and recycling is not being done because the cost of decomposition is too high to make it profitable.
When manufacturing gas sensors, durability tests are conducted, so the sensors need to operate not only at normal temperature and pressure but also under extreme conditions to some extent. In addition, there are standards required for alarms, and since the signal used for the warning cannot meet those standards with light alone, we thought it necessary to create a system to analyze the light from the sensor from outside.
As for the performance of the gas sensor, most gas sensors react at around 100 ppm, hence the 200 ppm level considered in this project may not be sensitive enough for commercialization.
Micro Bio Factory
We had an online meeting with Micro Bio Factory, which is developing microorganisms that produce aromatic compounds such as hydroxytyrosol, which is used in indigo and adhesives, to discuss the demand for carbon monoxide detection devices and how to spread awareness of synthetic biology in Japan.
At first, we considered using the device in smoking rooms and detecting the gas emitted from livestock feed. However, since smoking rooms are automatically ventilated, they did not see the need for detection. On the other hand, they thought it would be interesting to adapt the device to livestock feed. It is essential for our device to differentiate from existing sensors by making it possible to detect other gases and by using synthetic biology.
The reason why synthetic biology has not been recognized in Japan is that there is a strong prejudice against genetic modification. Besides, people who have never studied biology, have to start with hard-to-understand topics such as DNA composition and function. It is vital to explain in an “easy-to-understand” manner that breeding, which has been done as a matter of course since ancient times, is also a form of genetic recombination, and that synthetic biology technology is involved in our daily lives (production of mRNA vaccines). They also introduced us to activities for the eradication of malaria using the synthetic biology approach.
Nagaura Farm
We visited the cowshed at Nagaura Farm near Kyushu University. We introduced the outline of our project and heard some interesting stories. We were able to find out the market value of the device we are trying to produce, and we were also able to find out some practical issues such as whether we can use it.
Regarding the ventilation, even though it was pretty good, if feces and urine are not cleaned, bad smells containing ammonia may be emitted. It is stressful for cows when humans cannot detect bad smells, yet cows can do it with their acute sense of smell. It was said that there is a demand for developing a sensor that can be utilized as a guide for cleaning.
In terms of brightness in the cowshed, the amount of light is always maintained at a dim level, so the light from the sensor seems to be visible.
Regarding the compost, storing cow dung (especially from dairy cows) will cause bad odors, and neighbors sometimes complain. If we can visualize the standards that humans can detect, we may be able to increase the number of applications.
We also talked about silos, which are used for manufacturing and storing feedstuff and sometimes produce carbon monoxide, but they are rarely used now.
The farm we visited this time has no power supply reduction around it, so there is a demand for devices that operate with less power.
It was a great opportunity for us to think about the practical applications of our project.
National Institute of Information and Communications Technology (NICT)
We interviewed Hiroto Tanaka of the National Institute of Information and Communications Technology (NICT). The NICT is working on the development of a technology that uses the chemotaxis of microorganisms as a detector of chemical substances. One of the disadvantages of biosensors is that they take a long time to react, which is why they use chemotaxis. The reason for using chemotaxis is that the reaction time of biosensors is slow, but the reaction time of chemotaxis is fast. The project we are working on is aimed at producing fluorescence. We found out that the problems are the reaction speed and how to measure the fluorescence. We received a proposal to measure the fluorescence intensity using a smartphone. He also advised us that it would be easy to differentiate the biosensor if it could detect various poisonous gases by changing the emission time.
As for the accuracy of the biosensor, since it is related to the movement of living organisms, humans must analyze the movement of a group of living organisms through mathematical and statistical processing.
We also asked about the preservation of the genes of the bacterial strains. The company buys E. coli from an outside source, and they are still discussing how to continue culturing the same bacteria.
In addition, we were able to hear firsthand about the experiments being conducted at the National Institute of Advanced Telecommunications and Communications Technology, which was very helpful to us.
Future Vision
Weak signal
In gas sensors using only luciferase, the signal is weak, and it may be difficult or impossible to visually confirm the signal. Therefore, it is necessary to convert the information sensed by the sensor into a form that is easiest to grasp and use. Specifically, as advised by the National Institute of Information and Communications Technology (NICT), we can visualize the detected information by measuring the luminous intensity using a smartphone. Applications that can be used as illuminance meters on smartphones are in circulation, and we believe that they are highly versatile.(1) Alternatively, by using the ability of a photodiode or photoresistor to generate current or voltage when it senses light emission, a mechanism can be created to detect changes in fluorescence intensity and convert them into electrical signals for visualization. Another possible method is to use a transducer to convert the reaction of a bio-related substance when it is detected into a signal that can be easily detected, such as an electrical signal. Rather than visually confirming the luminescence, detecting the fluorescence externally in this way from the initial stage can speed up detection. As a method to intensify the light intensity, it is possible to use nano-lantern, which is a fusion of luciferase and fluorescent protein, to intensify the light intensity, and there are examples of its application in biosensors.(2)Dealing with Multiple Gases
At the cattle barn, we were told about the current situation where the barn was filled with carbon monoxide and putrefaction odor, or ammonia. The stage at which people and cows detect putrid odors differs greatly, and if we can detect ammonia at an early stage, it will be effective in introducing it to cowsheds and other barns in order to solve the situation where it is already too late for people to notice it. Also, by creating a device that detects carbon monoxide and ammonia at the same time, we will differentiate ourselves from existing sensors.(3) In the United States, where the installation of CO sensors is mandatory, the introduction of such sensors has been shown to reduce the number of carbon monoxide poisoning cases.(4)References
1.Mitsuru Hattori , Sumito Shirane , Tomoki Matsuda , Kuniaki Nagayama , and Takeharu Nagai.(2020).Smartphone-Based Portable Bioluminescence Imaging System Enabling Observation at Various Scales from Whole Mouse Body to Organelle /doi:10.3390.s20247166
2.Komatsu, N., Terai, K., Imanishi, A. et al. A platform of BRET-FRET hybrid biosensors for optogenetics, chemical screening, and in vivo imaging. Sci Rep 8, 8984 (2018). https://doi.org/10.1038/s41598-018-27174-x
3.Yang, J.; Zhou, J.; Lv, Z.; Wei, W.; Song, H. A Real-Time Monitoring System of Industry Carbon Monoxide Based on Wireless Sensor Networks. Sensors 2015, 15, 29535-29546. https://doi.org/10.3390/s151129535
4.Hsu, Wei-Ling & Ho, Chih-Yuan & Liang, Chiu-Kuo & Shiau, Yan-Chyuan & Hsieh, Hung Nien & Lai, Shu-Chen. (2019). Application of IoT in the Prevention of Carbon Monoxide Poisoning. Sensors and Materials. 31. 3465. 10.18494/SAM.2019.2482.