Our humanities practice is guided by four key questions: What are we doing, why are we doing it, how does the world affect us, and how do we affect the world? This helps us maintain a clear understanding of the essence and value of our actions.

The core idea of humanities practice is to build bridges between projects and reality through continuous interaction with the real world. Throughout this process, we focus on stakeholders, listening to their needs and collecting feedback, which serves as the basis for product improvements. This ensures that our products align with the needs of people and society.

To make the practice more systematic and professional, the team innovatively proposed the "5I Cycle" action framework, which consists of five interconnected stages:

Inspiration: Identifying directions from real-world problems and the potential needs of stakeholders.
Ideation: Developing project plans based on inspiration.
Information Collection: Focusing on gathering in-depth feedback from stakeholders.
Improvement & Interaction: Refining plans based on information and maintaining ongoing interaction.
Implementation & Outlook: Implementing plans and planning for the future.

The "5I Cycle" is a closed-loop iterative system that ensures we carry out our practice with respect and responsibility, allowing humanities practice to take root in reality and create value.

"Deadly bacterial wilt! Tomatoes are in danger!"
"Don’t worry, we will help you solve this problem!"

Located in Shanghai, the Jiangqiao Vegetable Wholesale Market supplies over 60% of the city’s fruits and vegetables. During our routine procurement process, we unexpectedly encountered Ms. Wang organizing a freshly arrived batch of tomatoes. Upon inquiry, we learned that these tomatoes are often infected with bacterial wilt caused by Ralstonia solanacearum—a bacterial vascular disease. Even more concerning is that Ralstonia solanacearum can spread rapidly through soil and irrigation water, not only causing widespread death of infected plants but also contaminating the planting area. This makes the land unsuitable for growing solanaceous crops for the next 3-5 years, resulting in devastating economic losses for Mr. Wang.

The vegetable vendor Ms. Wang, whom we interviewed, stated that bacterial wilt has caused "devastating blows" to her planting base: during the annual high-temperature and high-humidity season (June to September), bacterial wilt outbreaks are concentrated, reducing tomato yields by 30%-60% per season, and in extreme cases, even leading to total crop failure. Currently, although chemical agents such as copper-based preparations and thiazole zinc are widely used, their control effectiveness is limited and they lead to the accumulation of heavy metals in the soil. While grafting techniques (e.g., using wild tomato rootstocks) are somewhat effective, they are costly and complex to implement, making them unaffordable for small-scale farmers.

1. Severe Hazards of Tomato Bacterial Wilt
● Rapid and Deadly Plant Death: The pathogen blocks the vascular system, causing plants to wilt rapidly within 2-3 days. Once symptoms appear, plants almost invariably die, with a mortality rate nearing 100%.
● Significant Yield Loss: The disease outbreak occurs during the critical period from fruit setting to harvest. The pathogen spreads quickly, leading to yield reductions of 30%-50% in mild cases and total crop failure in severe cases.
● Soil Contamination Risks: The pathogen can survive in the soil for 2-7 years, creating "diseased soil." Continuous cropping or planting other solanaceous crops in such soil easily triggers outbreaks, undermining the planting foundation.
● Increased Planting Costs: Additional expenses are required for soil disinfection, grafted seedlings, and other control measures. Moreover, fruits from surviving plants are prone to deformities, resulting in lower marketability and reduced profits.
2. Current Control Measures
● Agricultural Control (Foundation): Rotate with non-solanaceous crops (e.g., rice, corn) for over 3 years; select disease-resistant varieties or use grafted seedlings with wild tomato rootstocks; avoid flood irrigation, maintain soil aeration, and reduce pathogen transmission.
● Soil Treatment (Key): Adjust soil pH (to 6.5 or higher) with lime before planting, or use methods such as solarization (high-temperature greenhouse treatment) and chemical fumigation (e.g., with thiazole zinc) to reduce pathogen levels in the soil.
● Chemical Control (Emergency): Apply root irrigation with agents like thiazole zinc or kasugamycin for prevention before disease onset. At the initial stage of disease, promptly remove infected plants and disinfect with quicklime. For healthy plants, use root irrigation + foliar spraying with the aforementioned agents to slow disease spread.
● Biological Control (Supplementary): Apply biological agents containing Bacillus subtilis or Pseudomonas fluorescens to the soil before planting. These beneficial bacteria competitively inhibit Ralstonia solanacearum, reducing the risk of disease outbreak.
3. Limitations of Existing Control Measures
● Agricultural Control Has Significant Limitations: Crop rotation requires over 3 years and depends on non-solanaceous crops, which is challenging for small family plots or continuous cropping areas. Grafted seedlings are costly, and disease-resistant rootstocks have limited compatibility, potentially affecting the taste of some varieties.
● Soil Treatment Yields Inconsistent Results: Solarization is climate-dependent (requires strong sunlight and high temperatures) and may not thoroughly disinfect deep soil. Chemical disinfection can leave residues, disrupt soil microbiota, and long-term use may lead to pathogen resistance.
● Chemical Control Is Passive and Limited: Chemicals can only prevent or slow disease spread and are ineffective against already symptomatic plants. Root irrigation requires precise application, which is cumbersome for large fields. Long-term chemical use may also cause potential soil and fruit contamination.
● Biological Control Lacks Stability: The effectiveness of biological agents is highly influenced by soil temperature, humidity, and pH. Beneficial bacteria exhibit low activity in low temperatures or acidic soils, resulting in unstable disease control. It is difficult to rely solely on biological methods for complete prevention.

After understanding the hazards of bacterial wilt, we aimed to find a control method that is "low-cost, highly effective, and environmentally friendly." To this end, we consulted Professor Wang Qiyao, Deputy Dean of the School of Biological Engineering at East China University of Science and Technology. Based on the latest research advancements, Professor Wang proposed that genetically engineering Escherichia coli to efficiently secrete erucamide could be an innovative solution to combat bacterial wilt. He elaborated on the technical principles and advantages as follows:

Erucamide is a natural fatty acid amide widely found in seeds of plants such as rapeseed and peanuts. It possesses the following characteristics:

1. Targeted Antibacterial Action: It specifically disrupts the cell membrane of Ralstonia solanacearum (by binding to the bacterial outer membrane lipoprotein OmpA, causing membrane perforation), while not inhibiting beneficial soil microorganisms such as rhizobia and actinomycetes.
2. Environmental Compatibility: It can be degraded by microorganisms in the soil into fatty acids and amines, with a half-life of only 7-10 days, leaving no residues or causing bioaccumulation.
3. Low Risk of Resistance: It functions by physically disrupting cell membranes, making it difficult for Ralstonia solanacearum to develop resistance through genetic mutations (a 2022 study in Applied and Environmental Microbiology confirmed no resistance observed after 12 consecutive generations of use).
4. Advantages of Engineered E. coli: E. coli reproduces rapidly (20 minutes per generation) and is easy to genetically modify. By constructing recombinant expression vectors, efficient secretion of erucamide can be achieved, with production costs only one-fifth of those of chemical synthesis methods.

Professor Wang Qiyao further pointed out: "The engineered E. coli can be formulated into a 'live bacterial agent' applied through root irrigation or soil mixing. It colonizes the tomato rhizosphere and continuously secretes erucamide, avoiding
photodegradation losses associated with foliar spraying while precisely inhibiting Ralstonia solanacearum in the rhizosphere—this is the key to controlling bacterial wilt (as the pathogen primarily invades plants through the roots)."

(2) Communication with Farmers — "Effectiveness, Affordability, and Ease of Use Are Core Priorities"
Ms. Cheng, whom we interviewed, shared with us the "three major challenges" of bacterial wilt control:

· Long Pathogen Survival and Hidden Transmission: The pathogen can survive in the soil for 2-7 years and spread stealthily through irrigation water and farming practices. By the time infected plants are discovered, the soil and surrounding plants may already be contaminated, missing the optimal window for control.
Difficulty of Reaching the Infection Site with Chemicals: Once the pathogen invades, it hides within the plant's vascular system. Conventional spraying methods struggle to penetrate effectively, and even root irrigation requires precise application to target the roots and vascular system. This poses significant challenges for large-scale fields and is largely ineffective for plants already showing symptoms.

Balancing Control Measures with Production Needs: Effective methods like crop rotation or solarization require long cycles or specific conditions, making them difficult to implement for small family plots or continuous cropping areas. While grafting and biological control are safer options, their high costs or variable effectiveness due to environmental factors make it challenging to balance disease control with farming profitability.

She specifically noted: "If there were a product as easy to use as 'spreading fertilizer,' with reasonable costs and able to protect crops for at least a month without disease outbreaks, we would definitely be willing to use it." This feedback made us realize that the product must not only be "effective" but also "low-cost and easy to use" to meet the practical needs of small-scale farmers.

(III) Brainstorming — "Establishing the Preliminary Project Design: Rhizosphere-Colonizing Engineered Bacterial Agent"

Integrating Professor Wang Qiyao's technical guidance and the needs of farmers, the team conducted brainstorming sessions and developed a preliminary plan centered on a dual-core strategy of "rhizosphere colonization + continuous secretion":

1. Engineering Bacterial Modification: Introduce the "erucamide synthesis gene cluster" into Escherichia coli BL21 (DE3) and incorporate a fatty acid induction system. This ensures that when tomatoes are infected by pathogens, their glycolytic pathway and erucamide secretion are activated to resist external pathogen invasion.
2. Formulation Design: The engineered bacteria will be formulated into "gel beads" (with trehalose added as a protective agent to enhance soil survival rates). Applied via root irrigation (100g per mu diluted in 50L of water), the engineered bacteria will colonize the surface of tomato roots and continuously secrete erucamide (secretion levels can reach 2.3mg/L based on laboratory shake-flask data).
3. Control Mechanism: Apply one round of root irrigation 7 days after sowing to allow the engineered bacteria to form an "antibacterial barrier" in the rhizosphere, inhibiting Ralstonia solanacearum infection. Apply an additional irrigation at the early onset of disease to rapidly eliminate pathogens in the rhizosphere, achieving a combination of "prevention + treatment."

III. Information Collection: Investigating Multifaceted Needs and Validating Project Feasibility

After preliminary project design, we conducted surveys and interviews with farmers, distributors, scientists, and consumers to understand their core suggestions for bacterial wilt control solutions. The key concerns of each group are as follows:

(1) Agricultural Producers: Focusing on Planting Pain Points
Tomato farm growers

Bacterial wilt, caused by Pseudomonas solanacearum, commonly occurs in solanaceous crops. It is highly prevalent in southern regions from May to October, particularly during the rainy season in June. The optimal conditions for bacterial growth are soil temperatures of 20–25°C and a pH of 6.6. The pathogen enters through wounds in the roots, with an incubation period of 10–20 days. Under suitable conditions, it can spread from individual plants wilting to large-scale die-off within 3–5 days, making control efforts passive.

Existing measures have limitations: Copper hydroxide root irrigation costs 200 RMB per mu (approximately 0.165 acres) and is effective for only 10 days. Grafted seedlings cost 1.5 RMB per plant (compared to 0.3 RMB for ordinary seedlings), resulting in an additional cost of 6,000 RMB for 5 mu, and they are prone to die under high temperatures.

Since a complete crop failure results in a loss of 5,000 RMB per mu, farmers are eager for new bacterial agents: with a cost of ≤300 RMB per mu and efficacy lasting one month. They are willing to try such agents to protect seedlings and reduce losses.

(2) Interview with Tomato Distributors: Focusing on Market Competitiveness
Owner of a vegetable wholesale store in Shanghai

The tomato market in Shanghai in 2025 is complex, with the core issue in open-field cultivation being the high incidence of bacterial wilt. Under ideal conditions, the yield per mu can reach 500 kg, but it drops sharply to 100 kg after infection, and diseased fruits are unsellable.

Price-wise, on August 25, the average wholesale price of tomatoes in Shanghai was 4.93 RMB/kg (ranging from 4.00 to 5.60 RMB/kg). Organic tomatoes sell for 12 RMB/jin (approximately 0.5 kg), while ordinary tomatoes sell for only 4 RMB/jin. However, organic farming prohibits the use of chemical pesticides, making bacterial wilt difficult to control. The industry hopes for a bacterial agent with organic certification and is willing to exclusively distribute products from such farms.

Farmers are cost-sensitive: if using the bacterial agent allows them to sell tomatoes for 8 RMB/jin, they are willing to grow them despite the increased costs, and distributors can also profit. If the selling price remains at only 5 RMB/jin, they are unlikely to try it.

(3) Interview with Scientists: Focusing on Compliance and Promotion Value

1. Wen Guangyue, Deputy Director of the Pesticide Safety Evaluation Research Center, Shanghai Academy of Agricultural Sciences

• Core biosafety requirements: Engineered E. coli falls under "genetically modified microorganisms (GMMs)" and must comply with the "Regulations on the Safety Management of Agricultural Genetically Modified Organisms." "The key is to demonstrate two points: first, that the engineered bacteria cannot persist and spread in the soil (e.g., they cannot survive in non-tomato rhizosphere environments), and second, that the degradation products of erucic acid amide are environmentally non-toxic."

• Policy support direction: The development of biological pesticides is encouraged under the Ministry of Agriculture and Rural Affairs' "Action Plan for Chemical Pesticide Reduction by 2025," which aims to promote the substitution of chemical pesticides with biological pesticides. The use of E. coli to synthesize erucic acid amide is a biological control method, aligning with the development direction of biological pesticides. Relevant departments may support this technology's transition from the laboratory to industrialization through special funding, subsidies, and other means during new product development and pilot production.

• Promotion suggestion: "First, conduct small-scale trials in facility greenhouses (10–20 mu) to collect data on efficacy, residues, and soil microbial diversity. Then, report to the Ministry of Agriculture and Rural Affairs for field validation. Only after passing the validation can it be included in the agricultural technology promotion catalog."

1. Zhang Peng, Researcher and Doctoral Supervisor, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences
(1) Optimization of Research Design
Prioritize projects combining both aspects to explore agricultural application potential.
Design research topics based on agricultural needs to enhance project competitiveness and practicality.

(2) Advancement of Biopesticide Development
Focus on developing biosynthetic pesticides to replace highly polluting traditional chemical pesticides.
Center on biosynthetic pathways to support green agriculture.

(3) Strengthening Microbial Technology
Utilize microbial fermentation for large-scale pesticide production to reduce costs and improve efficiency.
Genetically modify microorganisms to optimize synthetic pathways and overcome key technologies such as enzyme selection.
Introduce natural regulatory elements to increase target product yield.

(4) Improvement of Experimental Plans
Design validation experiments (e.g., infecting cherry tomatoes with Ralstonia solanacearum) to observe plant disease resistance.
Experiments should balance effectiveness, safety, and operability to support practical applications.

(5) Addressing Industrial Challenges
Optimize enzyme properties to resolve issues of insufficient target specificity.
Enhance research on microbial modification and regulatory systems to tackle multi-target regulation challenges.
Improve efflux systems to ensure stable product production.

(4) Enterprise: Opportunities and Challenges of Gene Fertilizer
Zhang Li, CEO of Tianjin Yuanyi Biotechnology
• Application and Policy of Synthetic Biology in Pesticide Replacement
Advantages: Environmentally friendly, advantageous policy approval
Issues: Long approval cycle, safety risks associated with E. coli chassis
Suggestion: Use plant symbiotic bacteria as chassis
• Technical Bottlenecks of Synthetic Biological Materials
Core issues: High cost (low yield, complex extraction), insufficient mechanical properties
Suggestion: Improve yield, optimize extraction, and design properties according to scenarios (e.g., low melting point materials)
• Innovation and Safety in Microbial Engineering
Innovation focus: Optimize genetic circuits, enhance metabolic efficiency
Safety priorities: Control DNA residues and harmful metabolites, select safe strains
• Future Trends and Industrial Applications of Synthetic Biology
Trends: Multidisciplinary integration, improve detection and fermentation processes, precise gene editing
Application expansion: Medicine, functional foods, and other fields

(5) Consumers: Focus on Health and Price
• Safety-first principle: Parents prefer tomatoes labeled "pesticide-free" for their children and are willing to pay a premium but worry about fake "pesticide-free" products.
• Technical awareness: When first encountering tomatoes produced using "engineered E. coli" technology, consumers are concerned about bacterial residues and health impacts. They require authoritative testing reports to be willing to purchase.
• Price acceptance: With ordinary tomatoes priced at 4 yuan/jin as a benchmark, consumers are willing to pay around 6 yuan/jin for new-technology tomatoes. If the price exceeds 8 yuan, they will switch to other vegetables.
• Residue concerns: Having heard about carcinogenic risks associated with copper-based agents, consumers smell tomatoes before purchase and avoid buying them if there is an unusual odor to mitigate residue risks.
• Traditional perception: Consumers believe "natural is better than artificial," trusting plant-derived erucamide but worrying about E. coli used in technology multiplying on tomatoes.
• Trust building: Consumers hope supermarkets will attach "microbial agent usage instructions" to relevant tomatoes, clarifying usage methods and residue status. Without such labels, they are hesitant to purchase.

IV. Subsequent Improvements: Optimizing the Plan Based on Demand and Assuming Social Responsibility
(1) Reflection: Focusing on Demand and Identifying Project Shortcomings
Through communication with various stakeholders, we identified three key shortcomings in the initial plan:
8. Insufficient stability of engineered bacteria: Farmers are concerned about the inactivation of bacterial agents under high temperatures (above 35°C), and distributors worry that a 6-month shelf life is difficult to achieve.
9. Costs exceeding expectations: Preliminary estimates put the cost of engineered bacterial agents at 350 yuan per mu, exceeding farmers' psychological expectation of "within 300 yuan."
10. Biosafety concerns: Agricultural authorities require proof that engineered bacteria "do not spread and pose no ecological risks," while consumers worry about "bacterial residues."

To address these issues, we have made improvements across three dimensions—"technical optimization, cost control, and safety assurance"—to ensure the plan aligns with practical needs.

(2) Targeted Improvements: Optimizing the Plan Across Four Dimensions

1. Enhanced Stability: Sustained-Release Design for Engineered Bacterial Formulations
• Development of sustained-release formulations: Encapsulate engineered bacteria in "trehalose-chitosan microspheres," which slowly release the bacteria over a 30-day period. This extends the effective duration (from 15 days to 30 days) and improves shelf life (75% or higher bacterial survival rate after 6 months of storage at room temperature).
• Compatibility optimization: Adjust the formulation pH to 6.5-7.0 to ensure compatibility with common water-fertilizer integration systems (drip irrigation, sprinkler irrigation). This eliminates the need for separate pesticide application, reducing labor costs for farmers.
2. Enhanced Safety: Triple Biosafety Design + Residue Control
• Environmentally friendly: Erucamide is a natural product molecule endogenous to plants. It can specifically disrupt the assembly of the type III secretion system in plant pathogenic bacteria, effectively inhibiting their pathogenicity. It has shown significant protective effects against various important bacterial diseases in crops, such as rice bacterial leaf blight and tomato bacterial wilt, making it suitable for developing environmentally friendly biopesticides.
• Food safety assurance: Engineered bacteria cannot colonize tomato fruits (fruit pH is 4.0-4.5, which is unsuitable for E. coli survival). Additionally, the formulation is applied to the root system and does not come into contact with the fruits, completely eliminating concerns about "bacterial residues."
3. Ease of Use: "One-Step" Bacterial Agent + Visual Usage Guidelines
• Pre-mixed formulation: Plan to combine engineered bacterial microspheres with water-soluble fertilizers to create "integrated efficacy-fertilizer granules." Farmers can directly apply them by broadcasting or flushing with water, without the need for separate pesticide mixing.
• Visual guidelines: Plan to create an illustrated "User Manual" and disseminate it through platforms like WeChat and Douyin to facilitate understanding among middle-aged and elderly farmers.

(3) Social Responsibility: Compliance and Science Communication in Parallel

1. Biosafety Compliance: Strictly Adhering to Regulatory Standards
Safety certification of erucamide itself.