Ancient Chinese murals carry rich historical information and have great aesthetic, artistic and scientific values, but they are currently very seriously damaged. Due to the different regions, times, production process materials, etc., the problems of different murals vary greatly, but mainly affected by both natural and man-made factors. Natural environmental factors have led to serious phenomena such as mural armor, crispy alkali, and hollow drums. At the same time, atmospheric pollution is becoming more and more serious, and the number of tourists is increasing year by year, all of which bring great threats to frescoes. At present, the restoration of ancient frescoes is a key issue in the field of cultural relics conservation, and it is also one of the more complicated and difficult tasks in cultural preservation. We hope to develop projects that can help mural restoration by means of synthetic biology, and help the restoration and preservation of Chinese murals.
During the project stage, we searched for real problems that could be solved by synthetic biology knowledge with the idea of "making a really useful project to solve a real problem". At the same time, another part of the team was reviewing papers to find experimental principles that we could use. But what really sealed the deal was an article on Dunhuang murals that a teacher shared with us. She suggested that we could do something with the Dunhuang murals. We thought at that time that this might be a possible direction. We all agreed that it would make sense to use new modern technology to preserve our heritage and our traditional culture after a thousand years. At the same time, the team members also found the experimental principle that would enable fresco restoration - Chao Zhong's team's research on biofilm mineralization. If we add color characterization to this, a restoration layer can be formed. That's how we settled on our current project.
Currently there are a large number of murals in China waiting to be restored by professional forces, but at present there are not even enough low-level talents for mural conservation and restoration, let alone high-level ones, and even if there are some mural restoration talents, they have not formed a team. At the same time, the daily monitoring and maintenance of ancient frescoes in many places is almost blank. The National Engineering Technology Research Center for Ancient Mural Painting Conservation was established on July 30, 2009 at the Dunhuang Research Institute, the first national engineering technology research center in the field of cultural heritage conservation in China. However, we regret to find that the research center has less than 200 technical staff, which is unable to meet the domestic demand for fresco conservation and restoration. The training of professional talents requires a long-term process of less than seven years and more than ten years. In addition, the time period for fresco restoration is very long. The main method of fresco restoration today is manual, and one of the most experienced fresco restorers can repair up to 0.02 square meters of frescoes a day, which is obviously not enough for China's mural paintings that need to be restored by the million square meters. In addition, we are equally concerned about the accuracy of manual restoration. To sum up, the main problems of fresco restoration today are: 1. time-consuming, restoration time cannot be shortened 2. prone to errors in manual restoration 3. few professionals and long training time. We believe that if we can develop a low-cost, short restoration method, we can not only solve the current situation of stretched fresco restoration, but also protect and inherit the splendid culture of mankind.
CsgA-3smfp---Our choice Our solution employs a technology based on blue light-controlled mineralization of biofilms, which was published in "Living materials fabricated via gradient mineralization of light-inducible biofilms". This technique was used in a paper published in Nature Chemical Biology titled "Living materials fabricated via gradient mineralization of light-inducible biofilms", demonstrating the feasibility of this technique. In the paper, the technique uses the E. coli biofilm as a platform for the light-controlled induction of blue light. The modified bacteria can sense external blue light to initiate the expression of fusion proteins, and the resulting biofilm can be further mineralized to form a composite material. Since the biofilm is inherently adhesive, the formed composite will adhere to the substrate. This biofilm can then undergo further mineralization. Overall, this study proposes a new method to prepare in vivo composites by using photoresponsive E. coli biopermeabilization, which can precisely control the shape of composites by setting different blue light patterns, as well as setting gradient blue light intensity to prepare in vivo composites with gradient density and gradient mechanical strength, providing a new way to prepare in vivo composites with fine structure, dynamic response and environmental adaptability. of the composite material. For the purpose of mural restoration, we we combine color with bio-permeable film. Our photocontrol system employs the control of T7RNAP activity by blue light to control the expression of the fusion protein, producing a bio-permeable film that can be further mineralized to form our desired composite. We ligated csga-3smfp to the same plasmid as amilcp to facilitate simultaneous expression. Co-transferring it with the photoreceptor system p70-VVD-VVD-T7R-179 will serve our purpose.
Fig1.Plasmid construction of blue light system
The combination of the viscous characteristics and color of the biofilm and the accurate control of the spatial distribution of the blue light will give us the material we anticipate for the restoration of the mural. Above, compared to traditional fresco restoration, our method has the following advantages. 1. Compared with manual restoration, the shape of the restoration can be more precisely controlled by setting the blue light pattern. 2. Through the blue light control can be generated on a large scale fresco repair layer, substantially increasing the speed of brush repair. 3. Reduce the talent threshold for fresco restoration. 4. It opens the attempt of restoring ancient frescoes with synthetic biology and provides ideas for subsequent research.
