Human Practices

Abstract

This project explores the development and application of bio-enzyme dyes as a sustainable alternative to conventional chemical dyes in the textile and personal care industries. Inspired by Hangzhou's rich silk heritage and the traditional green dyeing craft of Xiangyunsha, we initially identified a critical market bottleneck: while the environmental benefits of bio-enzyme dyes are recognized, their limited color spectrum severely restricts commercial adoption.

Guided by our iterative human practices, we conducted in-depth market research, including surveys and expert interviews. This revealed that consumers highly value the "safe and non-toxic" and "water-saving" attributes of bio-enzyme dyes and are willing to accept a moderate price premium. However, market trust depends heavily on authoritative certifications and proven performance, particularly regarding color fastness. From an industry perspective, successful implementation hinges on policy drivers, stringent cost control, and support from leading brands.

To address these challenges, we established a dual-focused strategy. Technically, we developed an innovative, cost-effective tyrosinase-based dyeing system utilizing a CipA-based self-immobilization strategy to enhance enzyme reusability and stability. Strategically, we pivoted from providing a technical solution to supplying standardized melanin pigment directly, significantly lowering the barrier to entry for downstream manufacturers. Furthermore, we expanded our vision from monochrome dyes to a multi-color platform using tyrosine derivatives.

Feasibility analysis across high-value application scenarios—such as high-end textiles, infant products, and hair dyes—confirms a viable "easy-to-difficult" market entry path. Our work demonstrates that marrying synthetic biology with traditional craftsmanship can pave the way for a greener future in dyeing, driven by a deep integration of technical innovation and societal needs.

Human Practice

Background & Inspiration

Hangzhou, a historic epicenter of China's silk industry, provides a compelling backdrop for this project, leveraging its deep-rooted silk heritage and sophisticated dyeing techniques. Xiangyunsha (Yunshao), a traditional silk dyeing and finishing craft originating from Southern China, uses purely natural raw materials and involves dozens of processes to form a unique texture, embodying the traditional wisdom of green dyeing and finishing[1]. However, its traditional production process is inefficient and struggles to meet modern-scale demands, while modern chemical dyeing processes, although more efficient, cause severe environmental pollution problems. Hangzhou itself once faced serious river pollution attributed to dyeing factories, but subsequent initiatives like the “Five Water Co-governance” program led to the relocation of many such plants, mitigating the environmental impact. Currently, environmental policies targeting highly polluting industries (especially textile printing and dyeing) are tightening globally, driving the industry's transformation towards green and sustainable directions[2-5]. Against this backdrop, biomanufacturing technology has become an important pathway for achieving a green upgrade in the textile industry due to its environmental friendliness and mild reaction conditions.

Idea V1

Existing research indicates that Tyrosinase, as a natural copper-dependent oxidoreductase, can efficiently catalyze the conversion of tyrosine to melanin under mild reaction conditions (neutral pH, room temperature), without the need for adding harmful chemical mordants, aligning with the principles of green chemistry [6]. Based on this, this project aims to combine modern biotechnology with traditional craftsmanship to develop a clean and efficient biological dyeing solution.

I. Technical Feasibility: Characteristics of Tyrosinase and Potential for Microbial Expression

Tyrosinase is widely found in plants, animals, and microorganisms, offering advantages such as high substrate specificity and mild reaction conditions, making it suitable for textile dyeing. Utilizing E. coli to express exogenous tyrosinase has established a research foundation. Microbial fermentation systems, characterized by short production cycles, controllable costs, and low environmental impact, are considered a viable pathway for the large-scale production of melanin[6]. By exogenously supplying substrates like L-tyrosine, extracellular synthesis of the pigment can be achieved, which not only simplifies extraction steps but also facilitates product regulation.

Furthermore, the enzymatic catalysis process does not require high temperatures, high pressure, or heavy metal mordants, thereby reducing energy consumption and equipment requirements, while also avoiding the introduction of harmful substances, resulting in good process compatibility.

II. Environmental Feasibility: Green Alternative and Sustainability

Traditional chemical dyes generate wastewater with high chromaticity, high chemical oxygen demand (COD), and heavy metal content during production and use, causing persistent environmental pollution[2-4]. In contrast, melanin synthesized via tyrosinase catalysis is a naturally degradable pigment, eliminating the input of hazardous substances at the source. Wastewater from enzymatic reactions is more easily biodegraded by microorganisms, significantly reducing the difficulty and cost of subsequent wastewater treatment, aligning with the principles of green chemistry and sustainable development goals.

Considering both policy direction and technical advantages, this project, based on the expression of tyrosinase in E. coli to conduct research on biological dyeing technology, demonstrates high feasibility in both technical pathway and environmental benefits. This research represents not only a modernization upgrade of traditional dyeing processes but also a concrete practice of the green biomanufacturing concept in the textile field.

Product V1

Based on the technical feasibility assessment, our first-generation product (Product V1) is positioned as a "Tyrosinase-based Biological Dyeing Technology Solution for Printing and Dyeing Enterprises". This solution aims to translate laboratory-stage biotechnology achievements into concrete solutions that enterprises can evaluate and trial.

Integrated Human Practice

Idea V2

During the Idea V2 phase, we identified a major market bottleneck: although bio-enzyme dyes were recognized for their environmental benefits, their limited color range—primarily black and gray—hindered commercial adoption. In response, we pivoted from a monochrome system to developing a multi-color bio-enzyme dye platform using tyrosine derivatives. This shift was inspired by literature showing that tyrosinase could produce varied hues, significantly enhancing the product's market adaptability and appeal.

In the early stages of the project, to understand the real market demand and acceptance of bio-enzyme dyes, we conducted in-depth interviews with staff from printing and dyeing factories and end-users.

In the initial phase of the project, to assess the market demand and acceptance of bio-enzyme dyes, we conducted in-depth interviews with staff from printing and dyeing factories and end consumers. The interview results revealed a key challenge: although the environmental attributes of bio-enzyme dyes are recognized, their color options are too limited, severely restricting commercial application.

Shen Pengfei, Technical Supervisor of Zhejiang Tangyi Fabric Co., Ltd., pointed out: "The environmental concept of bio-enzyme dyes is advanced, but the existing samples are limited to black and gray shades, making it difficult to meet the color diversity requirements of clothing brands." This view was echoed by a purchasing manager from a fashion brand, indicating that color richness is a core factor affecting market promotion.

Addressing this bottleneck, our literature review revealed that the catalytic products of tyrosinase are not limited to melanin. Research shows that by using tyrosine derivatives such as L-DOPA and methyltyrosine as substrates, various shades including light orange, reddish-brown, and even dark brown can be generated [7]. This finding provides a theoretical basis for breaking through color limitations.

Based on the above research results, the project direction underwent a significant adjustment: the next phase will focus on developing multi-color bio-enzyme dyes based on tyrosine derivatives, building a pigment platform that combines environmental friendliness with market adaptability, in response to the industry's urgent need for color diversity.

Idea V3

In Idea V3, we conducted comprehensive surveys and expert interviews to assess market readiness. The findings revealed that consumers highly value "safe and non-toxic" and "water-saving" attributes and are willing to accept a 10%–20% price premium. However, trust depends heavily on authoritative certifications and proven color fastness. From an industry perspective, successful implementation requires policy support, cost control, and collaboration with leading brands, highlighting the need for reliable performance and clear economic incentives.

To evaluate the market prospects of bio-enzyme dyes, this project conducted questionnaire surveys targeting both consumers and industry professionals, collecting 148 valid responses. The analysis is presented from three aspects: sample structure, consumption preferences, and market perception.

1. Survey Sample Composition (Sample Demographics)

The geographical distribution of the survey sample was primarily from new first-tier and second-tier cities (combined 58.78%), first-tier cities accounted for 20.27%, and areas below third-tier accounted for 20.94% (Figure 4A), effectively reflecting the perspective of the mainstream consumer market. Additionally, the respondents included 48 professionals from related industries (Figure 4B), covering textile dyeing, scientific research institutions, and environmental protection fields (Figure 4C). Although the industry sample size is limited, their professional insights provide important references for assessing the feasibility of technology implementation.

2. Consumer Behavior and Preference Characteristics

The survey showed that consumers purchase dyed textiles relatively frequently, with about 65% of respondents buying more than 2 items per quarter (Figure 5A). In purchasing decisions, material comfort (70.27%), cost-effectiveness (64.19%), and color design (64.19%) are the primary considerations, while the influence of eco-certification (32.43%) and brand (31.08%) is relatively weaker (Figure 5B). This indicates that current consumers pay more attention to the practical and economic attributes of the product itself; although environmental factors are attractive, they have not yet become the core purchasing driver.

3. Health and Environmental Awareness Status

Notably, nearly 80% of consumers expressed concern about the health impacts of dyes (Figure 6 left), while over 60% of respondents recognized the impact of the textile industry on water pollution (Figure 6 right). This reflects a high level of market concern for health safety and environmental impact, laying a cognitive foundation for promoting safer bio-enzyme dyes.

4. Advantage Recognition, Price Sensitivity, and Trust Building

The survey further revealed consumers' core demands for bio-enzyme dyes, price acceptance, and mechanisms for building trust, providing key insights for market promotion strategies.

High Advantage Recognition Focused on Health and Environment. Among the various advantages of bio-enzyme dyes, "safe and non-toxic" (73.65%) and "water-saving and eco-friendly" (52.70%) received significantly higher recognition than other options (Figure 7B). This indicates that attributes offering direct health benefits to consumers and positive environmental externalities constitute the product's most core appeal. In contrast, advantages leaning towards technical and commercial aspects, such as "controllable cost" (37.84%) and "color innovation" (34.46%), have weaker market perception. Therefore, initial market communication should focus on the two core value points: "safety" and "environmental protection."

Price Acceptance Concentrated in Moderate Premium Range. A high 74.32% of consumers are only willing to accept a price premium of 10%-20% (Figure 7A), showing high market sensitivity to cost. Acceptance for excessively high premiums (e.g., over 50%) is very low (8.78%). This requires that the product's cost must be controlled within a reasonable range during industrialization; a small premium is a key prerequisite for market penetration.

Trust Relies on Authoritative Certification, Concerns Focus on Product Performance. The core pathways for building market trust are "international eco-certification" (81.08%) and "third-party testing reports" (62.84%) (Figure 8B). Simultaneously, consumers' main concerns clearly point to the basic performance of the product itself: "technology maturity" (70.95%) and "color fading issues" (66.89%) are the biggest obstacles, followed by "price factor" (62.84%) (Figure 8A). This forms a clear logical loop: new products must first solve the trust issue through authoritative endorsements and eliminate core consumer concerns with reliable, stable performance (especially color fastness), before target customers are willing to pay a certain premium.

5. Industry Perspective and Key Factors for Technology Implementation

A questionnaire survey among industry professionals indicated that the key drivers for successful technology implementation are, in order: policy and regulation drivers (52.08%), cost control (50%), establishing recycling systems (41.67%), and procurement by leading brands (37.5%) (Figure 9). This points the direction for subsequent industry chain interviews and highlights that cost control is the core link connecting technology, policy, and the market.

Summary of Key Findings

This survey shows that consumers are highly concerned about the health and safety of dyed textiles, significantly recognize the "safe and non-toxic" and "water-saving and eco-friendly" advantages of bio-enzyme dyes, and generally accept a 10%-20% premium. However, building market trust heavily relies on objective evidence such as international certification and third-party testing, while consumers remain sensitive to technology maturity, color fading issues, and price.

From an industry perspective, technology implementation requires policy drivers, cost control, and industry chain collaboration. At the current stage, the focus should be on improving product performance and reducing production costs to enhance market competitiveness and acceptance.

Idea V4

Idea V4 marked a strategic and technical evolution: we adopted a CipA-based self-immobilization strategy to improve enzyme reusability and cut costs, while also optimizing the protein linker design for better activity. Critically, we shifted from supplying enzymes to providing standardized melanin pigment, lowering the entry barrier for manufacturers. This turn from a technical solution to a ready-to-use product, combined with a focused market entry strategy targeting high-value sectors, strengthened the project's commercial viability and scalability.

After determining the technical pathway centered on the CipA fusion protein, we further adopted expert advice to optimize the protein design and completed a major strategic adjustment to the product form.

Linker Optimization to Balance Expression and Activity

Professor Ye Lidan, an Associate Professor and PhD supervisor at the College of Chemical and Biological Engineering, Zhejiang University, whose main research directions are synthetic biology, metabolic engineering, and protein engineering, pointed out that the design of the linker peptide in the fusion protein is crucial for maintaining enzyme activity and stability. Although strict domain separation between CipA and tyrosinase is not necessary, a flexible Linker can provide the necessary spatial freedom for the two protein modules, reducing mutual interference.

To this end, we designed a systematic screening plan: construct TyrBm-Linker-CipA fusion expression vectors containing linkers of different lengths and universal flexibility, and screen for the optimal Linker construct that simultaneously achieves high expression yield and high catalytic efficiency by comparing inclusion body yield, soluble protein ratio, and enzyme activity, laying a solid foundation for subsequent scale-up production.

At the iGEM Hangzhou meet-up academic exchange event, in-depth questioning from peers and experts did not diminish the project's value but instead prompted us to think more deeply about technical bottlenecks and market positioning, leading to key breakthroughs.

Breaking the Color Limitation: From Monochrome to Multi-Color Platform

The pointed question from Professor Lian Jiazhang, "Is there a commercial prospect for dyes limited to black and gray?", prompted us to conduct a broader literature search. The results revealed that by using tyrosine derivatives or regulating reaction conditions, tyrosinase has the potential to generate a range of colors from light orange to dark brown. This discovery directly gave rise to the core direction in Idea V2 – developing a multi-color bio-dye platform, greatly enhancing the project's innovation and market value.

Achieving Precise Control: From Qualitative Description to Quantitative Model

Professor Tan Zhou's question about "how to precisely control the dyeing effect" pointed out the core challenge for moving laboratory technology towards industrial application – standardization and predictability. Inspired by this, we decided to go beyond qualitative descriptions and develop a quantitative prediction model based on the Langmuir adsorption isotherm. This model aims to accurately calculate the required dye dosage based on the target color depth, transforming our dyeing system into a reliable, predictable industrial-grade tool.

Multi-Dimensional Application Scenario Feasibility Analysis

Based on extensive research involving industry chain experts and end consumers, we have formed a clear judgment on the application feasibility of bio-enzyme dyes in three key areas. The overall strategy is to progress from easy to difficult, prioritizing entry into high-value-added, high-safety-demand niche markets.

The respondents in this survey were primarily from the 26-50 age group (combined 65%), who possess relatively strong purchasing power and decision-making authority (Figure 16 A). However, their awareness of bio-enzyme dyes is generally low, with over 60% of respondents indicating they are "not very familiar" or "completely unfamiliar" (Figure 16 B), suggesting that market education is an important prerequisite for future promotion. Based on interviews with industry chain experts (printing/dyeing mills, academics, dermatologists, hairdressers) and questionnaire data covering multiple dimensions, we have formed the following clear understanding of the application feasibility of bio-enzyme dyes in different fields.

High-end textiles like silk and wool. In the field of dyeing high-end textiles (like silk and wool), for bio-enzyme dyes to achieve industrial application, they must first meet the hard standards emphasized by printing and dyeing mills, such as color fastness, hue, and color diversity. In terms of market acceptance, the survey shows a solid consumer base for silk products (85% of respondents have purchase experience) (Figure 17 A left), and the core factors consumers focus on when purchasing are "whether it contains irritating substances" (75%) and "color fastness" (70%), rather than price (Figure 17 B). This provides an excellent entry point for bio-enzyme dyes promoting "safe and healthy" and "eco-friendly" concepts. Notably, consumer preferences for silk dyeing effects further reinforce this advantage, with a high 55% caring most about "no odor, non-irritating to skin" (Figure 17 C). Although current technology is not yet mature, the market already shows positive willingness to pay a premium: 40% of consumers are willing to prioritize buying bio-enzyme dyed silk at a 20% higher price, while another 50% maintain an open, wait-and-see attitude (Figure 17 A right). This indicates that once technical bottlenecks are overcome, this market holds significant commercial potential.

Infant textiles. Extremely high safety demands create clear market entry opportunities. Although 85% of respondents in this survey currently have no infants aged 0-3 in their households (Figure 18 A left), public concern for infant product safety is extremely high, with 80% of respondents being "extremely concerned" or "quite concerned" about dye safety (Figure 18 B). There is a clear market pain point: 30% of respondents have replaced infant products due to dye-related issues, while another 50% haven't encountered problems but expressed concern (Figure 18 C). The non-toxic, biodegradable nature of bio-enzyme dyes highly aligns with the extreme safety requirements of such products. Regarding price, although consumers show some sensitivity (55% hope the premium does not exceed 15%), 35% still fully accept a 15%-20% premium (Figure 18 A right). This suggests that by collaborating with authoritative certifications and well-known brands, infant products featuring bio-enzyme dyes with "absolute safety" as the core selling point can quickly establish market trust.

Hair dye and body art. The survey confirms that health concerns are a core pain point in the current hair dye market: 55% of respondents have reduced their dyeing frequency due to health concerns, while another 35% are concerned but still dye their hair (Figure 19 A left). This creates a strong demand for alternatives, with a high 85% of respondents expressing willingness to try or accept bio-enzyme hair dyes (Figure 19 A middle). Consumer preferences also point towards health attributes, with 70% prioritizing "healthy, low irritation" when choosing hair dye, far exceeding color effect (25%) and price (20%) (Figure 19 B). However, interviews with hairdressers (Figure 20) also pointed out practical challenges: the long operation time and heating process required by the current solution are difficult to accept by the mainstream market. Therefore, the success of bio-enzyme hair dyes depends not only on empirical proof of their safety – 90% of consumers believe they must pass "long-term usage safety tests" (Figure 19 C) – but also on optimizing the product formulation to improve user experience and clearly positioning it as a "care-oriented hair dye" product for health-sensitive groups. Regarding tattoo applications, the dermatologist highlighted (Figure 21) that while the superior safety profile of bio-based pigments is a significant advantage—eliminating risks of heavy metals and allergic reactions associated with traditional inks—their main limitation is shorter longevity. As the color doesn't penetrate as permanently, it fades more quickly. This positions them ideally for temporary tattoos and cosmetic body art, where safety and reversibility are prioritized over permanence. For applications such as temporary tattoos and cosmetic body art, the safety of bio-based pigments becomes a differentiating factor.

In summary, for bio-enzyme dyes to move from laboratory R&D to industrialization, bottlenecks such as cost, yield, color diversity, and performance stability still need to be overcome. Dr. Li Jingyu suggested improving enzyme catalytic efficiency and yield through enzyme engineering and optimizing fermentation conditions. The market promotion strategy should follow the principle of progressing from easy to difficult: prioritize entering areas where consumer safety awareness is strongest, price sensitivity is relatively low, and certain technical indicators (like persistence) can be adjusted, such as infant products, personal care (hair dye), and temporary body art. After establishing a reputation and iterating the technology in these fields, gradual expansion into the more demanding industrial textile sector can follow.