Team:CHINA CD UESTC/hp education
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DESCRIPTION
Do you know how to solve energy crisis utilizing biological methods? Have you ever heard about constructing a cell with enzyme? Nothing is too strange in the nature. There are many special properties of bacteria in the nature such as producing electricity, being attracted by magnet. Please read the description!
Background: why we chose EBFC
Along with the development of times and population growth, energy consumption is increasing rapidly. Up to now, the thermal power is the main source. According to BP Energy Outlook 2035 , we can find that the world's fossil fuel reserves are declining [4] , and the largest shift of shares give us an insight into the most likely shape of the future energy landscape! (Figure 1)
Figure 1. There have been some rapid shifts in fuel shares in power generation in the past: oil gaining in the 1960s and losing in the 1970s; nuclear picking up in the 1970s/80s and falling in the 2000s; gas rising through the 1990s and 2000s. In the Outlook, the largest shifts are the increase in the renewables share and the decline in the coal share [4] .
Among numerous renewable energy, bioenergy is a kind of clean renewable energy and a potential excellent substitute for fossil fuel. With the advance of biotechnology biofuel cell (BFC) which can convert the chemical energy of fuel into electric energy with enzyme or microbial tissue as a catalyst, has been researched widely.
Previous iGEM teams had done some studies about microbial fuel cell (MFC). iGEM13_Bielefeld-Germany made an Escherichia coli Fuel Cell platform to provide an efficient electron transfer from the bacteria to the electrode. iGEM14_LZU-China cloned a NO3-sensor sequence and riboflavin producing genes into Escherichia coli for anode and a gene coding chromate (VI) reductase Yief was cloned into E.coli for cathode. iGEM14_SCAU-China boosted up the level of intracellular NAD+ for higher electron transfer rate.
Biofuel cell is divided into microbial fuel cell and enzymatic biofuel cell (EBFC). EBFC is a special kind of fuel cell which uses organics as fuels and enzymes as catalysts. EBFC is generally separated into anode region and cathode region by proton exchange membrane. Fuels are oxidized under the action of enzyme in the anode region. Oxygen is reduced in the cathode region.
EBFC have broad application prospect, so we want to create a new type of device to develop the bioenergy.
Biocatalyst: Laccase, a kind of oxidoreductase
The main configurations of enzymatic fuel cells involve bioanodes based on glucose oxidase, glucose dehydrogenase or lactate oxidase and biocathodes based on copper oxidases such as laccase, tyrosinase or bilirubin oxidase. This concept was initiated by Mano et al. who implanted microbioelectrodes based on osmium redox hydrogels, in a grape obtaining thus 2.4mW at 0.54v [5] .
Laccases is a kind of copper-containing oxidoreductase. In the reduction reaction, the electron from the oxidation is transferred to the other three copper ions. These ions form a trinuclearic cluster, which transfers electrons to the terminal electron acceptor oxygen [6] .
Meanwhile, laccase has the property of oxidizing a wide range of substrates e.g., phenolic compounds, so it can be used in sewage disposal. Our project used these two enzymes and transformed the cathode. We constructed the expression vector of RFP + laccase and transformed it into E. Coli. The red fluorescence produced by RFP can be used as an indication of laccase’s concentration and activity. According to the method of electron transfer, EBFC can be divided into electronic media electrodes and direct electrochemical electrodes. Considered that the latter has high catalytic efficiency and small restriction by environment, we tried to enrich the laccase on the cathode to enhance the redox potential of our EFBC.
Figure 2. An electrochemical phenol biosensor based on the immobilization of laccase (Lac) on the surface of copper capped magnetic core–shell (Fe3O4–SiO2) nanoparticles (MNPs) [7] .
We obtained the laccase from BBa_K863005 . Traditional chemical approaches [7] of fixing laccase may affect the activity of laccase and are toxicological. So we hoped to find a better method!
A novel method of laccase immobilization
Of course using synthetic biological methods is a great idea to achieve our goal. Magnetotactic bacteria (MTB), a kind of bacteria that can be attracted by magnet, are a superexcellent choice for us. We noticed that MTB contains a fantastic structure-- magnteosome. It is a magnetic nano materials covered by biofilm. And the magnetosome is essential to magnetotaxis.After our investigation, we decided to connect laccase to the magnetosomes’ membrane to enrich them on the cathode surface.
Figure 3. Transmission electron microscopy images of several different MTB showing their distinctive cell and magnetosome crystal compositions and morphologies. Scale bars = 500 nm in bacterial images and 100 nm in magnetosomes images [8] .
After our investigation, we decided to connect laccases to the magnetosome's membrane to gather them on the cathode surface.
But there are two problems for us to solve. On one hand, MTB are anaerobic, it means they are hard to be cultured. On the other hand, it is difficult to modify them. So, we were aiming to construct a magnetosome expression system in E.coli to solve those problems. According to a paper in Nature nanotechonlogy , we confirmed that transferring four related operons can make other bacteria magnetotactic [9] .
Finally, we co-transferred all the vectors we constructed to make E.coli produce magnetosomes carrying laccase. The special magnetosomes would be used into our EBFC to improve the electron transfer efficiency!
Reference
[1] LI Dong-mei, MA Xiao-yan, WANG Ying, et al. Progress of construction of enzymatic biofuel cell[A]. Power Technology, 2010, 12: 1310- 04
[2] Serge Cosnier, Michael Holzinger, Alan Le Goff, Recent advances in carbon nanotube-based enzymatic fuel cells. BIOENGINEERING AND BIOTECHNOLOGY, 2014-04, doi: 10.3389/fbioe.2014.00045
[3] Serge Cosnier, Michael Holzinger, Alan Le Goff (2014). “Recent advances in carbon nanotube-based enzymatic fuel cells.” Bioengineering and Biotechnology 2:45, doi: 10.3389/fbioe.2014.00045
[4] Bob Dudley,et al. BP Energy Outlook 2035
[5] Mano, N., Mao, F., and Heller, A. (2003). Characteristics of a miniature compartment-less glucose/O2 biofuel cell and its operation in a living plant.J. Am. Chem. Soc. 125, 6588–6594. doi:10.1021/ja0346328
[6] Zeng J, Lin X, Jing Z, et al. Oxidation of polycyclic aromatic hydrocarbons by the bacterial laccase CueO from E. coli[J]. Appl Microbiol Biotechnol, 2011, 89(6):1841-1849
[7] Alper Babadostu, Ozge Kozgus Guldu, Dilek Odaci Demirkol, et al. Affinity Based Laccase Immobilization on Modified Magnetic Nanoparticles: Biosensing Platform for the Monitoring of Phenolic Compounds[J]. Biocontrol Science & Technology, 2015, 64:260-266
[8] Araujo A C V, Abreu F, Silva K T, et al. Magnetotactic Bacteria as Potential Sources of Bioproducts[J]. Marine Drugs, 2015, 13(1):389-430
[9] Kolinko I; Lohße A; Borg S; Raschdorf O; Jogler C; Tu Q; Pósfai M; Tompa E; Plitzko JM; Brachmann A; Wanner G; Müller R; Zhang Y; Schüler D. Biosynthesis of magnetic nanostructures in a foreign organism by transfer of bacterial magnetosome gene clusters.[J]. Nature Nanotechnology, 2014, 9(3):193-197
EDUCATION
We conducted interviews with the professor of the Hong Kong University Medicine School. Professor Zhaoyi Hu gave us many precious advice from the perspective of the safety.In the end, our members also get the chance to learn the general processes of sample treatment in medical research as well as separation and preservation methods of some bacteria strains.
iGEM and biology promogation
Purpose:
As we were alarmed to learn that most of Chinese believe that synthetic biology is harmful to human health. To combat this problem, we developed a dual-focus, comprehensive educational program targeting students. We thought that educate students is the most effective way to correct people’s conceptions. The team planned and carried out a series of iGEM educational lectures for aged 5-13 years old as part of the University of Electronic Science and Technology’s Education programs event.
1:
we went to kindergarten to teach the children some biological knowledge by way of science course.
2:
we held an interesting biology lecture on the experimental primary school of UESTC.
3:
we extended iGEM to the village schools in order to spread iGEM to remote areas which is low-education. We wanted to teach them more things they do not understand. Viewed from another aspect, we would like to propagation iGEM to wherever our capacity allows.
1. kindergarten
On June 18th 2015, following our experiment team instructor Xuelian Zheng, we team members went to the experimental kindergarten of UESTC, giving a fascinating and novel biological science lesson to kids. To attract kids’ interests, We presented our project the training road of Escherichia coli by pictures and cards. The story is mainly around an ordinary Escherichia coli. The protagonist went through four major difficulties, finally it developed a magnet absorbing ability like “Magneto” and realized its dream of getting super power.
lecture give a lecture
guidance Where the fun begins
cooperation Where the fun begins
fun Unforgettable eperiences
Besides, we also prepared a simple scientific experiment, swimming grapes. Changing water density by adding sugar, salt and other solutes, grapes under the water can float to the surface of it. The purpose of the experiment is to let kids realize that science is hiding in everyday life and hands-on operation in scientific inquiry is full of charm. At last, we gave every kid some okra seeds as gifts. By planting these seeds in their spare time, they can experience the process of life growth personally. We promised that we would harvest the okra fruits together in autumn.
Professor Zhaoyi Hu is head of Microbiology Department of Hong Kong University Medicine School, Infection and Immunity Joint Research Center of Hong Kong University. Their results research have a broad impact on international academic circles, especially the medical community .
2. primary school
On June 19th 2015, following our experiment team head instructor Lixia Tang, we team members went to the experimental primary school of UESTC to demonstrate an interesting synthetic biology project to students. Because students had learned the growth process of silkworms before, Mrs Tang introduced some fundamental synthetic biology research results like colorized silkworms, colorized roses and so on.
Furthermore, students also learned biological terms like DNA, RNA. Subsequently, Kun Yan took a hero of “ The Avengers” as an example to explain the main processes of synthetic biology experiments. By telling these, he led to iGEM, introducing many interesting iGEM projects of previous years. In the meantime, the students were keeping high enthusiasm, answered a lot of questions correctly. Finally, we organized each student to draw a picture about what synthetic biology project they want to do in the future and to share with others. After the activity, we gave every kids a nite writer pen as gifts. We deeply felt kids’ vigorous vitality and unlimited dream. Meanwhile we also planted a little iGEM seed in kids’ hearts, hoping it would sprout, bloom and fruit.
Let's see a collection of paintings.
3. Aid education
In terms of iGEM education and publicity, we want to spread iGEM further. During the summer vacation, we established two teaching teams and send them to the remote mountainous area to publicize iGEM. The members of the teams are all come from our iGEM club. They brought the children seven-day biology and science classes. Not only brought them knowledge but also introduced iGEM.
Our ‘Fluorescent’ teaching teamd went to Qiaolong country primary school which is located in Qiaolong Country, Zhouli Town, Baohua Township, Anyue County, Ziyang City, Sichuan Province. Although the facilities in that school is not good, the students are all hard working. Zhang Zelong which in the figure is our chemistry teacher, and he is teaching the children chemistry. Starting from basic chemistry knowledge, Mr. Zhang then talked about iGEM.
Mr. Zhang introduced some basic information about iGEM including the origin and all kinds of subject area especially the synthetic biology. Then he gave the students a brief introduction about some interesting iGEM subjects and showed the relation between those subjects and our life. In the end, Mr. Zhang told the children to pay more attention to their daily life to see if they can use some synthetic biology way to solve problems. He encouraged students to work hard and make those methods come true.
The ‘Eyas’ teaching team’s destination is Chenjiatan primary school, Lushaer Town, Xining City, Qinghai Province. During that time, our members explained iGEM and some synthetic biology knowledge by using projector. After children got aware of basic conception about synthetic biology, they used their pen to draw their life with biology technology. Their enthusiasm and interest showed us the future of synthetic biology.