What is fashion?

Iris Apfel, the "First Lady of fabric", whose fashion is a clever combination of clothes and accessories by color, texture and pattern, once said: "Fashion is more than trends.” So it can be said that fashion is about personality, about your personal attitude.

But fashion shouldn't just be about personality, it should also be about the environment. It is reported that the textile industry produces about 70 billion tons of dye-containing wastewater each year, and the resulting waste can be at least 50%. A large amount of dye-containing wastewater is directly discharged without proper treatment, or even directly used for farmland irrigation.[1, 2] Synthetic dyes discharged into the aquatic environment will cause water discoloration, prevent visible light from penetrating the water, thus affecting the photosynthesis of aquatic plant groups, further disturbing the local food chain, and greatly damaging the entire aquatic ecosystem[3]. Moreover, textile waste usually has biological toxicity, which may come from the dye molecules themselves, such as diazo compounds[4], or from metallic parts, such as chromium in acid dyes or copper in direct dyes[5]. These poisons can cause serious health problems in humans through bioenrichment and amplification.

During the 28th Conference of the Parties to the United Nations Framework Convention on Climate Change (COP28) in 2023, a sustainable fashion show was held at the in Expo City, with the intention of awakening the public to the concept of sustainable fashion. Therefore, how to develop personalized fashion while reflecting the concept of sustainable development has become an important focus of today's fashion.

To reduce production waste and pollution, we aim to use violacein as a dye and implement in situ natural pigment production and dyeing on fabrics through E. coli. This approach promotes environmentally friendly and safe fashion items. Additionally, we plan to enhance bacterial pigment production via RNA scaffolding, protein rational design, and metabolic pathway optimization. To further personalize the experience, our app will allow users to choose their preferred dyeing patterns.

We utilize a cell communication network based on control and production endpoints to achieve the bio-dyeing of fabrics with ' Neovio Dye.'

Violacein, slightly soluble in water, good stability under normal environment; It has affinity for some natural fibers and synthetic fibers, and can be used for textile dyeing with certain antibacterial effect. In addition, violacein is a naturally occurring compound that does not negatively affect the ecosystem and is widely used in agriculture, food processing and other fields.

The whole biosynthetic pathway of violacein involves a total of 6 steps, consisting of 5 enzymatic reactions and 1 non-enzymatic oxidative decarboxylation reaction, among which the reaction catalyzed by VioE is the rate-limiting step.

With the guidance of the central rule, from micro to macro, we use directed evolution to modify the promoter, optimize the codon to adapt to the codon tendency of E.coli K12, Two-site saturation point mutation and semi-rational protein design to improve the catalytic activity and stability of K12, and modify the metabolic network model of K12 to adapt to the production of violacein. Through this systematic transformation, we succeede in greatly increasing the production of violacein. In addition, we use a protein skeleton based on RNA phase separation to bind enzymes tightly, thus enhancing the efficiency of substrate transport between different enzymes.

To construct a communication module at the control and production sides, we design an orthogonal quorum sensing system. Control cells use C4-HSL and salicylic acid as signaling molecules. Different control cells synthesize different combinations of signaling molecules through C4-HSL synthase or salicylic acid synthase, which guide the production of VioC or VioE pigments in producer cells through the corresponding specific promoters, so as to realize different color printing patterns on the cloth.

To provide personalized production, we design a customized drawing module based on an orthogonal quorum sensing system and biological information storage, which can be divided into two parts: memory and reading.

We use Cre-LoxP system to achieve the memory function: each LoxP recognition site contains a terminator that normally prevents the expression of downstream signaling molecules. Upon blue light, the N and C termini of Cre polymerize to obtain recombinase activity, randomly excision of the terminator within the LoxP site[6], and turn on the expression of downstream salicylate synthetase or C4-HSL synthetase. Partial pixels are illuminated with blue light according to the light and dark of the customized image, and different combinations of signal molecule expression are generated to control the pigment production of different tones.

For the read module, the distinguishing mark of one archive from the others is the hairpin, which hides the sequence that turns on the riboswitch of the synthetase and can be opened by adding the correct RNA, exposing the above sequence and leading to normal expression of the enzyme.

In addition, in order to prevent salicylic acid-controlled VioC leakage, we modify HYER[7] as "deHYER" with no hydrolase activity to block the LoxP site so that it cannot be recognized by Cre.

With this system, we plan to implement pixel mode memory customization services based on optogenetics and RNA-dependent biodisks.