Three devices

    -> 66 new biobricks parts submitted and 39 parts proved to be effective. Please visit here for more information.

    -> In vivo and in vitro experiments on fatty acid degradation. Please visit here for more information.

    -> Cloning and testing the function of cellulose synthetase genes. Please visit here for more information.

    -> Using AdrA to activate cellulose synthetase and facilitate colonization.

    -> Modeling on gut microbiota and FadR regulation.

    Promoter design

    -> Novel promoter design: Pcar (BBa_K861171)

    -> Novel promoter design: PfadR(BBa_K861060)

    -> Setting up a standard of promoter design

    Methods we improved

    -> Expanding the cupric soap method to quantify fatty acid in medium. Please visit here for more information.

    -> A new method to measure the cellulose production. Please visit here for more information.

    -> An open software Fancy to measure the fluorescence of single bacterium

    The biobricks we improved

    -> PfadR (BBa_K861060), an improved design of BBa_J54222

    -> Improved function of two promoters BBa_K118011 and BBa_R0051

    Human practice

    -> Help HUST iGEM team to debug its project and modeling.

    -> Human practice on survey of GMOs and publicizing iGEM to the public.

    Favourite Parts

        Name Type Description Designer Length
    1 W BBa_K861171 RegulatoryPcar, synthetic promoter repressed by CRP Kuanwei Sheng 36
    2 W BBa_K861070CodingAdrA gene from E.coli K12Kuanwei Sheng1167
    3 W BBa_K861060 Regulatory PfadR, synthetic promoter with tandem FadR binding site Kuanwei Sheng76

    Part Related to Promoter Design

        Name Type Description Designer Length
    1 W BBa_K861160CodingCRP, cAMP receptor proteinKuanwei Sheng633
    2 W BBa_K861161GeneratorCRP with a RBS and a terminatorKuanwei Sheng757
    3 - BBa_K861162GeneratorConstitutively expresses CrpXian Xia, Kuanwei Sheng800
    4 - BBa_K861163GeneratorConstitutively expresses CrpXian Xia800
    5 W BBa_K861169RegulatoryIndirect regulatory device, activated at high glucose concentrationKuanwei Sheng1961
    6 - BBa_K861170RegulatoryPI ,Glucose-activated promoterKuanwei Sheng36
    7 W BBa_K861172Generator lambda cI generator controlled by PcstA (glucose-repressible promoter)Xian Xia1069
    8 W BBa_K861173ReportermRFP generator controlled by PcstA (glucose-repressible promoter)Kuanwei Sheng, Xian Xia500
    9 W BBa_K861174RegulatoryA control device for BBa_K861169Xian Xia1899
    10 - BBa_K861175ReporterEfficacy testing RFP generator of BBa_K861170 (PI)Kuanwei Shneg, Xian Xia905
    11 W BBa_K861176ReportermRFP expressed after PcarKuanwei Sheng, Xian Xia905
    12 - BBa_K861177GeneratorK861162+ K861175 Kuanwei Sheng1713
    13 - BBa_K861178DevicePcar efficacy testing device with CRP overexpressedKuanwei Sheng, Xian Xia1713
    14 - BBa_K861179GeneratorK861162+J23119Chang Liu843
    15 W BBa_K861061ReporterEfficacy testing RFP generator of BBa_K861060 (PfadR)Kuanwei Sheng945
    16 W BBa_K861062RegulatoryPfadR with FadR overexpressedKuanwei Sheng1840

    Parts Related to Fatty Acid Degradtion

        Name Type Description Designer Length
    1 W BBa_K861500 Coding FadL, Long-chain fatty acids transporter from E.coli str. K12 Kuanwei Sheng 1465
    2 W BBa_K861001 Generator FadL with a strong RBS and a double terminator Kuanwei Sheng 1465
    3 W BBa_K861002 Generator Constitutively expressed FadL Kuanwei Sheng 1508
    4 W BBa_K861003 Generator PfadR regulated FadL Kuanwei Sheng 1549
    5 W BBa_K861003 Generator PfadR regulated FadL Kuanwei Sheng 1549
    6 W BBa_K861010 Coding FadD, an inner membrane-associated acyl-CoA synthase Kuanwei Sheng 1605
    7 W BBa_K861011 Generator FadD with RBS and terminator Kuanwei Sheng 1729
    8 W BBa_K861013 Generator IPTG induced FadD Kuanwei Sheng 1792
    9 - BBa_K861014 Generator Constitutively expressed FadD Kuanwei Sheng 1772
    10 - BBa_K861015 Generator Constitutively expressed FadD Kuanwei Sheng 1772
    11 - BBa_K861016 Generator PfadR regulated FadD Kuanwei Sheng 1813
    12 W BBa_K861020 Coding FadE ,acyl-CoA dehydrogenase Kuanwei Sheng 2445
    13 - BBa_K861021 Coding FadE gene for fatty acid degradation from Salmonella enterica LT2 Kuanwei Sheng 2592
    14 W BBa_K861022 Generator FadE with RBS and terminator Kuanwei Sheng 2569
    15 - BBa_K861023 Generator S-FadE with a RBS and a terminator Kuanwei Sheng 2716
    16 W BBa_K861024 Generator IPTG induced FadE Kuanwei Sheng 2632
    17 - BBa_K861025 Generator Constitutively expressed FadE Kuanwei Sheng 2612
    18 - BBa_K861026 Generator Constitutively expressed FadE Kuanwei Sheng 2612
    19 - BBa_K861027 Generator Constitutively expressed FadE Kuanwei Sheng 2612
    20 - BBa_K861028 Generator PfadR regulated FadE Kuanwei Sheng 2653
    21 - BBa_K861029 Generator PfadR regulated S-FadE Kuanwei Sheng 2800
    22 - BBa_K861030 Coding FadB, gene for fatty acid degradation from E.coli K12 Kuanwei Sheng 2190
    23 W BBa_K861031 Coding FadJ, gene for fatty acid degradation from E.coli str. K12 Kuanwei Sheng 2145
    24 W BBa_K861032 Coding S-FadB gene for fatty acid degradation from Salmonella enterica LT2 Kuanwei Sheng 2190
    25 W BBa_K861033 Generator FadB with a RBS and a terminator Kuanwei Sheng 2314
    26 W BBa_K861034 Generator FadJ gene with a RBS and a terminator Kuanwei Sheng 2269
    27 - BBa_K861035 Generator S-FadB with a RBS and a terminator Kuanwei Sheng 2314
    28 - BBa_K861036 Generator IPTG induced FadA and FadB Kuanwei Sheng 3570
    29 W BBa_K861037 Generator IPTG induced FadI and FadJ Kuanwei Sheng 3672
    30 W BBa_K861038 Generator IPTG induced S-FadA and S-FadB Kuanwei Sheng 3673
    30 W BBa_K861038 Generator IPTG induced S-FadA and S-FadB Kuanwei Sheng 3673
    30 - BBa_K861400 Coding FadA protein coding sequence for fatty acid degradation Kuanwei Sheng 1164
    31 W BBa_K861041 Coding FadI, gene for fatty acid degradation from E.coli str. K12 Kuanwei Sheng 1311
    32 W BBa_K861042 Coding FadA, gene for fatty acid degradation from Salmonella enterica LT2 Kuanwei Sheng 1164
    33 - BBa_K861043 Translational_Unit FadA with a RBS Kuanwei Sheng 1185
    34 W BBa_K861044 Translational_Unit FadI with a RBS Kuanwei Sheng 1332
    35 W BBa_K861045 Generator FadI with a RBS Kuanwei Sheng 1288
    36 - BBa_K861046 Generator PfadR regulated FadA and FadB Kuanwei Sheng 3590
    37 - BBa_K861047 Generator PfadR regulated FadI and FadJ Kuanwei Sheng 3693
    38 - BBa_K861048 Generator PfadR regulated S-FadA and S-FadB Kuanwei Sheng 3591
    39 - BBa_K861050 Coding FadR, fatty acid sensor from E.coli str. K12 Kuanwei Sheng 720
    40 - BBa_K861051 Generator FadR with a RBS and a terminator Kuanwei Sheng 844
    41 - BBa_K861052 Generator Constitutive expressed FadR Kuanwei Sheng 887
    42 - BBa_K861345 Generator IPTG induced S-fadE Kuanwei Sheng 2779
    43 - BBa_K861346 Intermediate IPTG induced promoter with FadA, intermediate part for BBa_K861036 Kuanwei Sheng 1248
    44 W BBa_K861347 Intermediate IPTG induced promoter with FadI, intermediate part for BBa_K861037 Kuanwei Sheng 1395
    45 W BBa_K861348 Intermediate IPTG induced promoter with S-FadA, intermediate part for BBa_K861038 Kuanwei Sheng 1351
    46 - BBa_K861349 Intermediate PfadR with FadA, intermediate part for BBa_K861046 Kuanwei Sheng 1269
    47 - BBa_K861350 Composite PfadR with FadI, intermediate part for BBa_K861047 Kuanwei Sheng 1416
    48 - BBa_K861351 Composite PfadR with S-FadA, intermediate part for BBa_K861048 Kuanwei Sheng 1372

    Parts Related to Cellulose

        Name Type Description Designer Length
    1 W BBa_K86150 Coding BcsA,cellulose synthetase, catalytic subunit Xian Xia 2619
    2 W BBa_K861101 Generator BcsA with RBS and terminator Xian Xia 2743
    3 W BBa_K861102 Generator BcsA controlled by promoter repressed by CRP Xian Xia 2787
    4 - BBa_K861110 Coding BcsB,regulator of cellulose synthetase Xian Xia 2340
    5 - BBa_K861111 Generator BcsB with RBS and terminator Xian Xia 2464
    6 - BBa_K861112 Generator BcsB controlled by promoter repressed by CRP Xian Xia 2508
    7 - BBa_K861120 Coding BcsZ, endo-1,4-D-glucanase Xian Xia 1107
    8 - BBa_K861121 Generator BcsZ with RBS and terminator Xian Xia 1231
    9 - BBa_K861122 Generator BcsZ generator repressed by CRP (directly) Xian Xia 1275
    10 - BBa_K861130 Coding BcsC,cellulose synthetase subunit Xian Xia 3474
    11 - BBa_K861131 Generator BcsC with RBS and terminator Xian Xia 3598
    12 - BBa_K861132 Generator BcsC controlled by promoter repressed by CRP Xian Xia 3642
    13 W BBa_K861140 Coding GalU,glucose-1-phosphate uridylyltransferase Xian Xia 909
    14 W BBa_K861141 Generator GalU with a RBS and a terminator Xian Xia 1033
    15 W BBa_K861142 Generator GalU generator repressed by CRP (directly) Xian Xia 1077
    16 W BBa_K861150 Coding GalF, putative regulatory subunit for GalU Xian Xia 894
    17 W BBa_K861151 Generator GalF with a RBS and a terminator Xian Xia 1018
    18 W BBa_K861152 Generator GalF generator repressed by CRP (directly) Xian Xia 1062

    Parts Related to Colonization

        Name Type Description Designer Length
    1 W BBa_K861071 Generator AdrA gene with a RBS and a terminator Kuanwei Sheng 1293
    2 W BBa_K861072 Generator Constitutively expressed AdrA Kuanwei Sheng 1336
    3 W BBa_K861073 Generator Constitutively expressed AdrA Kuanwei Sheng 1336
    4 W BBa_K861074 Generator Pcar regulated AdrA Kuanwei Sheng 1337
    5 - BBa_K861090 Coding YhjH Gene From E.coli str. K12 Kuanwei Sheng 768
    6 W BBa_K861091 Generator YhjH gene with a RBS and a Terminator Kuanwei Sheng 892

    Brief Answers to Safety Questions

    Welcome to our Safety Page. We will first answer the safety questions asked by iGEM headquarters briefly, and then discuss safety issues associated with our project in detail. In addition, we will provide our ideas and practice on guaranteeing and developing biosafety.

    Q1. Would any of your project ideas raise safety issues in terms of: Researcher safety, public safety, or environmental safety?
    No. Our design is based on the commonly used nonpathogenic E. coli K.12 strain and genes we manipulated are original genes in E. coli. The protein products, at least from current understanding, will cause no harm to researchers, the public and environment. In addition, strict lab practice is executed to further ensure safety.

    Q2. Do any of the new BioBrick parts (or devices) that you made this year raise any safety issues? If yes,
    Did you document these issues in the Registry?
    How did you manage to handle the safety issue?
    How could other teams learn from your experience?

    Yes, we will discuss this question in latter part of this page (Safety Considerations of Our Biobrick parts and Our Project).

    Q3. Is there a local biosafety group, committee, or review board at your institution?
    If yes, what does your local biosafety group think about your project?
    If no, which specific biosafety rules or guidelines do you have to consider in your country?

    Yes. All materials obtained have received the approvals from the department's laboratory management committees. We are also obliged to observe the regulations of Teaching Centre of Experimental Biology and apply for approval for materials before we start our project.

    Q4. Do you have any other ideas how to deal with safety issues that could be useful for future iGEM competitions? How could parts, devices and systems be made even safer through biosafety engineering?
    Some classified measures should be taken according to the safety of the material. For example, plasmids that may harm the safety, when submitted, should receive more attention and have a stricter package. Some harmful byproducts during experiments should be eliminated properly.
    We have done our human practice aiming at understanding attitude of the public towards genetically modified baceria and publicizing biosafety ideas to the public, which we think should be popularized to other teams in future iGEM competitions.

    General Safety Issues

    In this part, we will illustrate organisms, reagents and equipments we use that may cause safety problems, and introduce our operation standard, management and trains protecting the team members, public and environment.
    As above, all the organisms and DNA hosts are not of high individual or community risk. Until now, the only used organism is E. coli K.12 (and some of its varieties, for example, DH5α, a RecA mutated strain). Our current lab of basic-biosafety level 1 is safe enough to manipulate this strain. Only the genome (a generous present from University of Dundee iGEM team), but not the living Salmonella enterica was manipulated in the lab, and the genes from it are homogeneous of E. coli K.12, not associated with pathogenesis. We will not implement our future experimental plan with microorganisms of risk group 2 or vertebrates in our current lab, for too low is the biosafety level and no animal facilities.
    To manipulate microorganisms, an ultra clean cabinet is used and strict aseptic technique is followed. All experimenters have been trained on foundation microbiology technique and biosafety. All microorganism contacting vessels are sterilized before and after experiments in appropriate protocols. Also, all microorganism materials will be sterilized before discarded. In this way, we believe that no public or environmental harm will be caused by the experimental organisms. In addition, no one in our team will be hurt by the experimental organisms.
    The genetic modifications we make will change metabolism of bacteria. However, there is no evidence both theoretically and experimentally that these modifications will improve the pathogenicity of the bacteria or cause damage to environment even taking the risk of horizontal gene transfer into consideration. The effects of expressing gene adrA regarding infectivity and pathogenicity on E. coli is not clear now, but it still can be easily controlled in the lab environment without human ingestion. Also, we will insert a death device into the bacteria cell when we construct the whole system (still far from now) to avoid the proliferation out of control. For more information about gene safety, please read the next section and documents of our relevant parts on registry.

    We have considered the potential harmful chemicals and equipments, as listed below:

    • Basic molecular experiments: NaOH, HCl, SDS, acrylamide, TEMED, ethanol, IPTG, liquid nitrogen, β-mercaptoethanol, xylene cyanol FF.

    • Bacteria culture: ampicillin, kanamycin, chloramphenicol.

    • Chemical analysis and measurements: acetone, cupric acetate, Sudan III, Congo red, Coomassie Brilliant Blue G-250, Coomassie Brilliant Blue R-250.

    • Equipments: UV lamp, supercentrifuge, heating equipments (alcohol burner, PCR amplifier, water bath, dry bath), electrophoresis apparatus, -80℃ refrigerator, ultrasonic cell disruptor.

    All of these are regular reagents and apparatus in a molecular biology laboratory. The risks of them come from inflammability, explosibility, irritation, corrosivity, toxicity, carcinogenicity and physical injury. But none of them raises special safety issue, with chemical hood, emergency shower, normal personal protection, safety management and safety training.
    Only trace amount of antibiotics are used. Inactivated will they be before discared.

    Emergency ShowerEmergency Shower

    Safety Considerations of Our Biobrick parts and Our Project

    In this section, we are going to answer safety question 2 in detail, taking the potential risk in the future into concern.
    The main safety challenge we must face is that as a practical bacteria therapy our direction is, we shall demonstrate that the “E. coslim” will not harm its host when it is developed completely. As few experiments we can do in such limited time, we have done a series of theoretical work to solve problems in this field. Intestine-colonized pathogenic E. coli may cause immune responses, following by diarrhea, inflammation and fever (although the strain we use is considered non-pathogen). Thus we plan to transplant the whole synthetic system to another organism (for example, Bacillus subtilis, has proved safe in human intestine). We know that it is hard as the two organisms are very different on transcriptional mechanisms, but we believe the work of establishing model system (that is what we are doing) in E. coli will make it easier. Also, as the rapid development of synthetic biology and gut microbiology, we hope in the near future, we can modify the genome of E. coli to change it a safe intestine microbe.
    Another risk is that when the engineered bacteria get higher efficiency on energy production, they could proliferate out of control. To forestall this situation, we design a “death” device (for more information, click on Death) using D-xylose as inducer. It means if you want to stop weight losing, what you have to do is to eat some D-xylose, and the “E. coslim” will die, shed from the intestinal wall and be poured out. What is more, designed as a two-plasmid system, it prevents all possible horizontal gene transfers.
    Further safety issues will be raised and discussed in future experiments, including those operates in intestinal model and animals (For more information, click on Future Perspectives).

    Safety Management and Practice

    Our project has past a review of an expert committee, of which members are professors or associate professors of microbiology, genetics and bioengineering. Safety issues are considered seriously before they approved our design. We have consulted a few experts for safety questions about both artificial intestinal bacteria and experiments. Their advices help us improve the safety of the whole planning system. For that, we thank Dr. Yulan Wang and Dr. Tiangang Liu so much. Our lab is supervised by Teaching Centre of Experimental Biology, Wuhan University (TCEB, whose leader is our instructor Dr. Zhixiong Xie). An expert group of this centre formulates safety guidelines and guarantees their performance in all teaching labs. All experiments we do past its review. Our safety management system includes the followings: Management of Chemicals, Equipments and Experimenters: Chemicals and equipments are registered in TCEB before they are available for us. Equipments are checked and maintained regular. And an entrance guard system is used to ensure only the admitted could enter the lab.

    • Responsibility distribution: All members worked in the lab are divided to three groups. The group leaders arrange schedules of experiments after assessing safety issues in the group (for example, the safety train of the experimental executer). Every member records his/her experiments in detail in the notebook of the group. Each group takes responses for cleaning and checking risks in the lab in turns. The group leader takes responses to the team leader. The team leader reports regular on safety to engineer Miss Long Yan, who is authorized by TCEB and manages the lab.
    • Management of Chemicals, Equipments and Experimenters: Chemicals and equipments are registered in TCEB before they are available for us. Equipments are checked and maintained regular. And an entrance guard system is used to ensure only the admitted could enter the lab.
    • Training: Our team members have been trained after Guidance of Student Experiments formulated by TCEB.

    Guidence of Student ExperimentsGuidence of Student Experiments

    Biosafety and Publicity

    We believe that biosafety is not an issue which should be only considered inside biological lab, but also around people and communities. Spreading knowledge of biosafety to the public will help eliminate misunderstanding and prejudice, from which the science and all the people will benefit. We hope that sharing this idea with all iGEM teams can be useful to take advantage on biosafety.
    To investigate public attitude towards our project and to publicize our biosafety ideas are what we do for our human practice. As “eating bacteria” is somehow an unacceptable concept now, we would like to find whether people know the truth about biosafety issues raised by bioengineered bacteria, or they are just panicked by their imaginary “bacteria”. And then, after initiating basic knowledge of microbiology, gene engineering and synthetic biology, we shall take a look on if people’s opinion to biosafety issues will change. In this way, we will estimate the value of our scientific publicity.
    The rational discussions of biosafety we take with the public do not limited on our project, but also hotspot issues such as transgenics and stem cell therapies. For more information, please click on Human Practice.

    Introducing a Simplified Intestinal ModelIntroducing a Simplified Intestinal Model

    Protocol for Fluorescence Measurement

    Minimal Medium


    For 1L Medium add

    Na2HPO4·12H2O 15g

    KH2PO4 3g

    NaCl 1g

    NH4Cl 0.5g

    After autoclaving, add:

    MgSO4(1mol/L) 2mL

    Bacteria strain:CaCl2 100μL

    Triton X-100 (as emulsifier) 2uL


    1.For M9 medium using oleic acid as sole carbon source, various amount of oleic acid was first emulsified 1:1 with 10% Triton X-100. M9 medium was then slowly added with constant vortex. M9 medium with high concentration of oleic acid was diluted by M9 medium with triton to form various concentrations;

    2. For M9 medium using glucose as sole carbon source, M9 medium with high concentration of glucose was diluted by M9 medium to form various concentrations.


    1. Seed liquor which was activated over night was inoculated into M9 medium which contains different concentration of oleic acid. And it was then incubated at 37℃ for 24 hours;

    2. After 24h of incubation in 24 well plates in 37℃, bacteria culture was centrifuged at 3000rmp for 5min, washed and resuspended in PBS;

    3. We detected the OD600 and fluorescence of using SpectraMax M2 plate reader (Molecular Devices) .Excitation at 584 nm and emission at 607 nm were used. All fluorescence was normalized with cell density by measuring the absorbance at 600 nm.

    Protocols of Cupric-Soap Reaction

    To test metabolism of long fatty acids, we used oleic acid as sole carbon source in mediums, and used cupric-soap reaction to determinate oleic acid concentration preliminarily.

    Modified M9 minimal medium with emulsified oleic acid as sole carbon

    Minimal medium was the same with that in Materials and methods for PfadR

    What's Important:

    Slowly pour M9 minimal medium into mixture of oleic acid and Triton X-100 to get more homogeneous solution.

    Analysis the concentration of the oleic acid in the medium by cupric-acetate method


    1.Collect 5 ml medium which has been used to cultivate bacteria. Then centrifuge the medium at 3000rpm for 10 min to separate bacteria and medium;

    2.Decant 3ml supernatant liquid into a 10ml EP. Add 3ml acetone to the liquid, 1ml at a time, shaking 10-20 times before adding another 1 ml in order to avoid the effect of the ions of the liquid during the extraction progress;

    3.Add 3 ml isooctane once ,shaking for at least 90s, stand for 2min or longer until layering completely;

    4.Collect 3 ml clear isooctane in a 5 ml EP, Add 800?l cupric-acetate (5% m/v, adjust pH to 6.8 with pyridine), Shaking for 90 seconds, stand for 2min or longer until layering completely;

    5.Detect OD of organic phase in a spectrometry at 715nm.

    The Standard Curve

    We add 1.6ml, 3.2ml, 4.8ml, 6.4ml, 9.6ml, 11.2ml oleic acid into 3ml M9 medium to generate a gradient. The absorbency is measured as described in the protocol.

    Guidence of Student Experiments

    We slightly modified the methods provided by Kwon and Rhee, 1986, adding the extraction step, for it is indispensable when bacteria are in the medium. The standard curve is still very close to that of the paper's, which proves the applicability and accuracy of our modified protocol.

    Krebs-Ringer Phosphate(KRPD Buffer Solution)


    Solution A:

    For 100 mL:

    NaCl 7.5985g ; KCl 0.3727g ; CaCl2 0.1054g; glucose-H2O 0.9495g,

    Solution A:

    For 100 mL:

    NaH2PO4·2H2O 0 .2964g ;Na2HPO4·12H2O 2.9011g,

    After dissolving, add MgSO4·7H2O 0.3130g

    Mix A solution and B solution, add 790ml dd H2O, then regulate pH to 7.2~7.4 using 1M NaOH/1M HCl, finally add dd H2O to a final total volume of 1L.


    1. cultivate cells in 1 liter of medium to late exponential phase;

    2. harvest by centrifugation at 35℃;

    3. wash twice with 2 liters of warm(35℃)0.05M potassium phosphate buffer (pH 7.4) containing 1%(v/v) Triton X-100;

    4. resuspend in 0.05M potassium phosphate buffer (pH 7.4) containing mercaptoethanol;

    5. add sufficient volume of buffer to give a concentration of about 50mg(dry weight) of cells/ml;

    6. disrupt cells with a Bransor Sonifier for 1min. The treatment was applied for 15s intervals, under 4 ℃;

    7. centrifuge at10,000×g for 30min;

    8. decant supernatant liquid for enzymatic assay, the protein concentration was determined by the biuret method;

    9.analyze fatty acid oxidation in cell-free extracts

    Note: little oxidation was observed when less than 1mg.

    Reaction Mixture

    1.0ml of freshly oxygenated Krebs-Ringer phosphate(pH 7.4)

    Palmitate-1-14C, 20nmole (80,000 counts/min)

    CoA, 1 μ mole

    NAD, 1μ mole

    ATP, 1μ mole

    Succinate, 10 n moles

    Supernatant protein, 1~5 mg

    dd H2O to a final total volume of 2.0ml

    Cellulose Detection

    1. Inoculate the bacteria into liquid LB medium and then incubate it for 24 hours at 37℃;

    2. After centrifugation, supernatant is preserved for use, while deposits are resuspended with PBS and adjust to OD600 1.0;

    3. Exceed cellulase was used to digest cellulose in supernatant and deposits. After the cellulase is added, 1mL solution was sampled every 3 min and cellulose of the sample was inactivated immediately;

    4. Ten minutes later, the reduce sugar is detected in all the samples with or without cellulose;

    5. 2mL DNS solution is mixed with the sample, and incubated in boiling water for two minutes, then it is cooled rapidly;

    6. After 9 mL ddH2O being added into the solution, record absorbance at 540nm;

    7.The Standard Curve of glucose concentration

    Then all tubes was treated in the same way with that in step 5 and 6.

    8.Calculate the amount of cellulose in cell culture.

    In vitro Experiment

    1. inoculate 100μl bacteria into 100ml LB , shaking at 37C overnight .

    2. inoculate 1L LB using the culture above at the next morning , on the scale of 1:20 .

    3. Separate above medium into 250ml flask , shaking at 37C for 3-4h .

    4. 8000 rpm , 6min to collect the bacteria .

    5. Using PBS to resuspend the bacteria to 50mg / ml .

    6. Ultrasonication 1min , every 15s having an interval to cool on the ice .

    7. Using Coomassie blue staining to measure the concentration of the total protein .

    8. In 2ml reaction system , add 5ul oleate ,40 ul Triton 10% , 1ml Krebs-Ringer phosphate buffer , 10nmol succinate , 1 umol COA , 1umol ATP , 1 umol NAD .

    9. react at 37C for 6h

    In this experiment , the concentration of total protein in the cell extracts of the five sample are almost the same , so we assume that adding the same volume guarantee the same amount of protein is added .

    The reaction system for the control BBa_R0011+(R0011), BBa_R0011+fadE , BBa_R0011 + fadD , BBa_R0011 + Samonella A Samonella B , BBa_R0011 + fadI fadJ : 1ml Krebs-Ringer phosphate buffer , 10nmol succinate , 1 umol COA , 1umol ATP , 1 umol NAD , 1ml cell extract .

    The reaction system for BBa_R0011+fadD and BBa_R0011+fadE mixture : 2ml Krebs-Ringer phosphate buffer , 20 nmol succinate , 2 umol COA , 2 umol ATP , 2 umol NAD , 1ml cell extract for each gene.


    The reaction system for BBa_R0011+fadD , BBa_R0011+fadE , and BBa_R0011 + Samonella fadA Samonella fadB mixture : 3ml Krebs-Ringer phosphate buffer , 30nmol succinate , 3umol COA , 3umol ATP , 3 umol NAD , 1ml cell extract for each gene.

    The reaction system for BBa_R0011+fadD , BBa_R0011+fadE , BBa_R0011+Samonella A Samonella B , and BBa_R0011+fad I fad J mixture :4ml Krebs-Ringer phosphate buffer , 40nmol succinate , 4umol COA , 4umol ATP , 4 umol NAD , 1ml cell extract for each gene

    Plate Assay

    1. J12107- AdrA and control RBS was incubate and vortex in LB medium with Ampicillin overnight

    2. OD600 was measured; LB was then added to make the two test tubes had the same OD600

    3. Bacteria were inoculated by sterilized needle piercing a pre-labeled 0.3% agar LB semisolid plate for 4-5 minutes in super clean bench.

    4. Carefully placed the plate horizontally in a 37 degree incubator overnight. Avoid shaking of the plate.

    5. Clones on the plate were observed.

    Materials and Methods of SDS-PAGE

    Guidence of Student Experiments

    Coomassie Blue Stain

    -Coomassie brilliant blue G-250 50mg

    -95% ethanol 25ml

    -85%H3PO4 50ml

    -H2O, adjust to 500ml


    Destain solution

    -methanol 250ml

    -acetic acid 50ml

    -H2O adjust to 500ml

    2x SDS loading buffer

    -0.5mol/l Tirs-HCl(PH6.8) 25ml

    -10%SDS 8ml

    -50%glycerol 20ml

    -2-mercaptoethanol 2ml

    -1%Bromphenol Blue 4ml

    -H2O adjust to 100ml

    10xSDS-PAGE running buffer

    Tris base, 30.3 g

    M glycine 144.1g

    SDS 10 g

    -H2O adjust to 1L


    Protein expression

    1.inoculate the liquid strains into LB medium supplement with 50μg/mL ampicillin, incubate the medium at at 37℃ until OD600 reaches 0.6;

    2. Separate the culture into two test tubes. Add IPTG into one of two tubes at a final concentration of 1mM to induce the expression of

    3. 1 mL of the culture is sampled every hour. After centrifugation, deposits was suspended with 300 μL PBS and 200 μL 2x SDS loading buffer, then incubated in boiling water for 15 min.

    4. 10μl of samples was load in lanes, run the SDS-PAGE

    5. Stained the SDS-PAGE 5 hours

    6. Destain the SDS-PAGE until you can see the protein band.

    team history

    Dec. 2011

    WHU iGEM team was established

    Dec. 2011 to Feb. 2012

    Every one presented their own idea, then we discussed the feasibility of these ideas.

    Feb. 2012

    The final project was determined, named E.coslim

    Mar. 2012

    We finished an outstanding presentation. Our reply was approved by the leaders of college of life sciences, Wuhan University.

    Apr. 2012

    Our iGEM team was divided into 3 groups—group of Sheng, group of Xia and group of Mei.

    Apr. 2012 to prsent

    Experiments started….

    Apr. 2012

    Group of Sheng: FADR was connected to pSB1A2 plasmid carrier

    FADR was connected to RFP gene

    Group of Xia: starting to connect genes of CI control system

    Testing the function of CI control system

    Group of Mei: YhjH/ FadE/ FadD/ FadL gene was connected to pSB1A2 plasmid carrier

    May. 2012

    Group of Sheng: FadB/ FadJ gene was connected to pSB1A2 plasmid carrier, then BBa_B0030(RBS) as well

    Group of Xia: They devised two promoters p110 and p101, which were expected to be controlled by glucose. However, they failed.

    Group of Mei: YhjH/ FadE/ FadD/ FadL gene was connected to BBa_B0030(RBS)

    June 2012

    G of S: FadR was connected to low-copied plasmid carrier.

    sFadB and sFadA genes were connected to BBa_B0030 (RBS)

    sFadE gene was connected to pSB1A2 plasmid carrier

    G of X: the connection of genes, which were relative with cellulose, was finished.

    Another two promoter were devised, p1 and p2

    G of M: YhjH/ FadE/ FadD/ FadL gene was connected to BBa_B0024 (terminator)

    July 2012

    G of S: FadJ was connected to BBa_B0024 (terminator), sFadE gene was copied by PCR technology

    On the front half of this month, they conducted several pre-experiments of oleic acid test

    On the next half month, they started normal experiments of oleic acid test

    G of X: started to test the function of p1 and p2

    G of M: YhjH/ FadE gene was connected to BBa_J23100 (promoter)

    Finish the standard curve of oleic acid test

    Aug. 2012

    G of S: sFadE was induced to point mutation, then it was connected to BBa_B0030 (RBS) and BBa_B0024 (terminator) respectively

    sFadB was connected to BBa_B0030 (RBS) and BBa_B0024 (terminator) respectively.

    G of X: test the function of cellulose-controlled genes, having got satisfying results

    G of M: copied Adra gene and finished the connection of BBa_B0030 (RBS), BBa_B0024 (terminator) and BBa_J23107 (promoter), BBa_J23114 (promoter) respectively. FadE/YhjH/FadD/fadL were connected to BBa_J23107 (promoter), BBa_J23114 (promoter).

    Sep 2012

    G of S: Transferred all the parts in pSB1A2 into pSB1C3, Tested the function of PfadR, Characterized the effect of each gene on fatty acid consumption, started to set up the platform for in vitro experiments.

    G of X: Transferred all the parts in pSB1A2 into pSB1C3, tested the function of cellulose system. Repeat the test of the function of cellulose-controlled genes.

    G of M: Transferred all the parts in pSB1A2 into pSB1C3, test the function of Adra/YhjH.


    About E.coslim by Kuanwei Sheng

    In order to help people lose weight, besides our three devices, we also have come up with many other creative ways.

    Ⅰ.Short chain peptides synthesis

    Recent researches have indicated that some short chain peptides in intestine have effect on inhibiting appetites, therefore decrease the food intake. We thus formed the idea that we could synthesis a DNA chain that encodes those short peptides.

    Ⅱ.Biosynthesis of L-carnitine

    L-carnitine is a molecule that facilitates the progress of transporting fatty acids into mitochondria where these fatty acids will be disintegrated. We once considered use L-carnitine to help the host metabolize fatty acid better. However, the biosynthesis of L-carnitine has too many derivatives or the pathway is patented by others.

    Ⅲ.Xylose isomerase

    Xylose is a prebiotics that can hardly be absorbed by human. We consulted many papers and find that glucose can be converted into xylose by xylose isomerase. Therefore, we thought maybe we could lower the glucose available in intestine by expressing xylose isomerase. However, this process is shown to be reversible latter. Mutated the sequence of the protein may generate high converting rate, yet it is too laborious and risky for a short time project.

    Other novel ideas

    Tackle Water bloom by Tong Wang and Kuanwei Sheng

    Since the detrimental effects caused by cyanobacteria to the environment such as making water carcinogenic have become a serve global problem, we therefore tried to employ E.coli as an expression system to eliminate these detrimental effects. When we first took over this project, we thought about limiting the growth of cyanobacteria. Along with the process we got to read a large amount of relevant papers about cyanobacteria, we found that not only the main detrimental effects caused by cyanobacteria is attributed to its product which is a cyclic peptide called microcystin, but also microcystin can regulate the population density. Then we came to realize the importance of microcystin and began to search information about it. Through over this process, we discovered a gene cluster which is responsible for the microcystin degradation pathway. It encodes four enzymes——MlrA、MlrB、MlrC and MlrD. Also, we found that some non-toxic cyclic peptides produced by cyanobacteria such as Anabaenopeptin B and Anabaenopeptin F can induce lysis of cyanobacteria. The latter finding can be utilized as an effective cell population density control mechanism. Thus we thought about constructing two independent systems to eliminate cyanobacteria, one about inducing lysis of cyanobacteria and the other about degrading microcystin. Finally we gave up this project because of the reasons that these gene clusters are too large to be expressed in E.coli and that E.coli cannot survive in the sea, however, we still feel proud of these fancy ideas.

    Desalination of sea water by Kuanwei Sheng

    We came up with the thought that engineering bacteria can intake ions like Na+, cl-, Mg2+ and etc. under special stimulus. Also, under another certain stimulus, the bacteria can export those salts out of cells for reuse. Therefore, we can use these bacteria to desalinize sea water and extract the salt the same time. However, there is no such ion channel that can meet our needs.

    Sense the earthquake By Min Ye

    We once tried to find proteins that can sense vibration and construct a pathway to report that vibration. However, we are not able to find the protein that can meet our needs.

    Auto plasmid preps By Kuanwei Sheng

    We thought about constructing a synthetic protein that combines zinc finger protein which can recognize the specific sequence of DNA and signal peptide that can make proteins be exported out of the bacteria by secretion pathway. Therefore, it is possible that plasmid can be exported out the cells together with the zinc finger protein.

    Outer Membrane Vesicle (OMV) to treat cancer By Kuanwei Sheng

    We thought to use Outer Membrane Vesicle (OMV) to treat cancer. Specifically, we thought about localizing antibody that can recognize certain cancer on the surface of OMVs via signal peptides. Also, we thought we may localize cell division inhibitor protein or protein that lead to cell death inside the OMVs. Therefore, we hoped that the OMV excreted by the bacteria can recognize and kill cancer cells.

    Multicell Yeast By Wenxiong Zhou

    Transform the yeast from a single-cell microbe to a multi-cell organism by setting bistability of gene expression among cells of yeasts adhered in amalgamation.

    To kill superbacteria

    Now with the spread usage of the antibiotics, many bacteria adopt ability to fight against the antibiotics. And now it’s a big problem that antibiotics are no longer useful as before. So to kill these bacteria, Jing and her group thinks they can device some proteins or artificial micromachine to detect DNA that code proteins contributing to the ability to degenerate antibiotics. And then by transferring these plasmids coding artificial proteins or micromachines, they can inhibit the expression of enzymes or proteins degenerating antibiotics.

    A Letter from Fancy

    There is a very meaningful sentence in the novel The Lord of the Ring: when the respected old Billbo was going to leave the village in which he had lived for many years, he gave a lecture--”The people among you whom I recognize haven’t reached half whom I should do, besides, among those whom I love are less than the half I should do, either.

    None of us need to fight in a war or fight with monsters. However, all of us have indeed fought and stuck to the very end, regardless of whatever obstacles to overcome and whatever precious to sacrifice.

    The greatness lies in the persistence to do the ordinary things perfectly. We are all inspired by our design. However, the gap between the repetitive, seemingly endless molecular cloning and the last magic probiotic can easily wreck the passion. To the opposite, most of us have successfully endured the monotonous life. Sometimes the enzymes just don’t function well. Other times the PCR never get right for some unclear reasons. We just survived those really despair moments and made one step closer to our goal.

    And those heart-touching scenes are clear as if they happened yesterday. Regardless of our persuation to wait for the rain to stop, our captain determined to fetch the induction cooker in his dormitory to perform an reaction as soon as possible (We don’t have an appropriate heater in our lab). When his figure disappeared in the dark and rain, words failed me; when I got a message at 3 o’ clock in the midnight, the excited tune claiming that we no longer needed to worry about our competent cells overwhelmed me with tears; when I heard that our “artist” having caught a cold but promised that he would complete all the pictures of the web site in time, I fell into silence again; every time when Xian Xia stayed overnight in the lab, the room would be quite tidy and all the reagents would got replenished. When I saw this in the next morning, I was greatly touched.

    Most of us has sacrificed much time to pursue personal interest. We just decrease the time for required exams for going abroad, for working in our own labs, and for some courses we are really interested in, let alone our hobbies. No time for travelling, reading lasted paper on interested topics, shopping, chatting with friends and so on. However, after the complaints and anguish, we finally reached such a peaceful and simple spiritual state that we just want to try our best to get the best result.

    A man who never experienced iGEM in WHU can never really understand the complex of feelings: glory and dream, perseverance and persistence, joy and tears. You can never image how brave and respected my teammates are, how many efforts and love they have put in the team, and how strong the relationship we have built since the team has been organised.