May 5

We made acquaintance with members of NWU-CHINA-A and NWU-CHINA-B through Northwestern China iGEM Meetup held on May 5, 2021, during which they demonstrated us their brainstorm about the orientation of the project:

 (1)Using biological surfactants to remove heavy metal ions in the soil;
 (2)The inversion of ginsenoside.

In turn, we shared with them the project we were considering as well:

 (1)Synthesizing tryptophan with microbes to improve sleep quality;
 (2)Using double-promoter-controlled fungal synthesis to forestall tooth decay;
 (3)Removing heavy metal contamination from the soil.

Delighted by our common interest in heavy metal removing, NWU-CHINA-B and us made a further communication surrounding this point. We exchanged some existing ways to remove heavy metals from soil and analyzed the feasibility of each project. Also we provided some methods to help NWU-CHINA-A improve their design by using the phase distribution equilibrium equation. By this chance, we three teams established partnership and provided contact information to each other exploring the possibility of cooperating to the utmost through in-depth exchanges of ideas and thoughts, which paved the way of our further collaboration.

July 1

We invited NWU-CHINA-A to interview Prof. Xu Dan of Xi’an Jiaotong University with us. This interview provided us a more profound comprehension of synthesis biology and aroused our enthusiasm of digging deeper in relevant fields. According to the feedback of NWU-CHINA-A, the interview also strengthened their confidence in the market capacity of biological dyes and the potential of promoting their product Tyrain Purple to the market.

After that, members in charge of human practice had a work exchange. Our team member Dong Daiyun demonstrated the vision of human practice part, interviews with experts, enterprise visiting, questionnaires and education programs included. NWU-CHINA-A expressed their enthusiasm of collaborating in video education and public exhibitions.

July 3

We discussed about our progress and the existing problems. We were searching for a promotor with a lower level of leaked expression and we plan to make use of the profilin fitz to deter the fission of germs. On this basis, we were going to select the promotor with low leaked expression again to further suppress the fission so that we could operate more easily during experiment. This inspired NWU-CHINA-B to study the relation between methanol and AOX1, the promotor they had chosen.

After few days, we exchanged our progress of experiments with NWU-CHINA-B. They informed us that they were applying P. pastoris as chassis cells. Using E. coli DH5α as chassis cells, we were especially interested in the way they cultured the yeast so they thoroughly explained us the detailed process. Meanwhile, as we were confused about output measuring, NWU-CHINA-B came up with the idea of measuring with HPLC and offered to help us with it.

July 28

Team leaders of three teams had a discussion over the problems arising from the experiments as well as the attribution within each team. NWU-CHINA-B was facing the problem that the concentration of plasmid, the recovery after electrophoresis and the conversion rate were all not high enough to bring about a conspicuous result while we were bothered by unsuccessful conversion, unfavorable positive contrust, erroneous sequencing and negative recovery. In addition, we exchanged our methods of team-managing and our further plans for the projects. While NWU-CHINA-A also met difficulties in measurement for lack of microplate reader and corresponding experience in operation.

To solve our problem about sequencing, NWU-CHINA-B recommended us Sangon Biotech (Shanghai) Co., Ltd. to for help. Moreover, the came up with the idea that the negativity of our post-electrophoresis recovery could be a consequence of wastage. In turn, we suggested that they enlarge the number of microbes cultured and improve the utilization of centrifuge tubes in order to augment the concentration of plasmid and thus forestall inconspicuous experiment results.

NWU-CHINA-A analyzed the possible reasons that might lead to the failure of our transformation screening, suggesting it might be caused by the quality problem of antibiotics. Considering this, they provided us with antibiotics from other manufacturers to help us eliminate this problem. We also shared with them our experience in using the microplate reader and suggested improvements to their current measurement methods. We exchanged suggestions of modifying and thereafter. NWU-CHINA-A assisted us in replenishing the questionnaire, making the research work of both teams initiate smoothly.

In the following week, benefiting from this exchange, all three of our teams had overcome the previous problems and made progress in the experiment. Following oue suggestions, NWU-CHINA-B had significantly augmented the concentration of their plasmid, making it possible to push their experiment forward successfully.

The antibiotics provided by NWU-CHINA-A successfully solved the problem of screening failure that had troubled us for nearly a month, while our help to them also greatly accelerated their screening progress.

September 10

We had a face-to-face discussion of the progress and the outcomes we had got. We shared exchanged thoughts about Wiki designing and human practice as well.

Knowing that NWU-CHINA-B had difficulties in modeling, we introduced the modeling results our team had obtained and the design ideas of the model to them. We proposed a closer collaboration between the two teams on modeling and expressed a willingness to help. In the next few days, we worked with NUW-CHINA-B to analyze the induction mechanism of the promoter they used and the enzymatic reaction pathway in ginsenoside production. Based on these, we explained to them basic mathematical models such as Logistic Equation, Michaelis-Menten Equation and Law of Mass Action, and helped them analyze enzyme yield and catalytic efficiency in their projects with these equations. We also introduced them the method of using MATLAB to complete equation calculation and ploting, and provided them the code and image results.

In the end, we presented each team the souvenirs designed by ourselves in memory of our collaboration.

It’s worth emphasizing that NWU-CHINA-A and XJTU-China have established Part Base in 2019, which offers free sequencing part for other iGEM teams to utilize directly. With the expectation of continuing this program, we collaborated with NWU-CHINA-A, NWU-CHINA-B and other teams to enrich the content of Parts Base on the basis of 30 previously build parts, enhancing the significance of the project.

September 21

We helped NWU-CHINA-B to get contacted with our instructors, who offered suggestions about project summarizing and result analyzing. Also, our instructor demonstrated them the latest advances of ginsenoside inversion. For instance, crude enzyme generated from Lactobacillus paralimentarius LH4 is also proved to be able to catalyze the conversion from ginsenoside Rb1 to CK. In their words, the talk with our instructor widened their horizon of ginsenoside inversion, making them discover more possibilities of the realm.

On top of that, we visited the laboratories of our team, NWU-CHINA-A and NWU-CHINA-B successively to talk about the current experimental progress and problems. It was worth mentioning that during the visit to their lab, we gave NWU-CHINA-A some guidance for their experimental operation and the use of some professional equipment. For instance, we showed them how to use ELIASA and microplate reader properly. Outsides the lab, we showed them around our campus and introduced the history of our university.

Both of XJTU-China and NWU-CHINA-A constitute the earliest teams established in Xi’an that have hitherto inherited. Each year we kept a close and in-depth collaboration. We are partners and friends, supporting, encouraging and inspiring each other to advance jointly.