Bacteria that Make Bioplastics While Cleaning Wastewater

A biotechnological innovation is transforming two environmental problems into a single solution: genetically modified bacteria that produce high-quality bioplastics while simultaneously decontaminating industrial wastewater. This dual-benefit process not only reduces treatment costs but also generates biodegradable materials that could replace up to 30% of conventional plastic in specific applications.

The Process: From Waste to Resource

Key Biological Mechanism

Certain bacteria, such as Cupriavidus necator and Pseudomonas putida, possess the natural ability to:

1. Feed on organic pollutants present in wastewater
2. Accumulate intracellular polymers as an energy reserve
3. Produce PHAs (polyhydroxyalkanoates), fully biodegradable bioplastics

2025 Innovation: Improved Strains

• Greater efficiency: 85% conversion of the organic load into bioplastic (vs. 40% in 2020)
• Tolerance to toxins: They process water containing heavy metals and xenobiotic compounds
• Optimized yield: 0.5 kg of PHA per m³ of treated water

Practical Applications in 2025

Food and Beverage Industry

• Brewery: 1,000 L of wastewater → 0.5 kg PHA + clean water
• Dairy: High-value whey treatment
• Oil refineries: Fat removal and flexible bioplastic production

Textiles and Fashion

• Dry cleaning wastewater: Specific bacteria for azo dyes
• Circular production: On-site PHA buttons, zippers, and labels

Agriculture and Livestock

• Swine manure: 90% nitrogen reduction + biodegradable mulch production
• Agro-industry: Treatment of vegetable wash water

Characteristics of Bacterial Bioplastics

Improved Technical Properties

• PHA (Polyhydroxyalkanoates):
  • Biodegradability: 6-24 months in soil vs. 400-500 years for conventional plastics
  • Thermoplasticity: Injection and extrusion moldable
  • Gas barrier: Ideal for food packaging
  • Biocompatibility: Approved for medical applications (Sutures, Implants)

Specialized Types

• PHB (Polyhydroxybutyrate): Rigid and crystalline, similar to polypropylene
• PHBV (Polyhydroxybutyrate-covalerate): Flexible and resistant, similar to PET
• P34HB: High elasticity, for films and bags

Industrial-Scale Projects

Barcelona Plant (Spain)

• Capacity: 5,000 m³/day of urban wastewater
• Production: 2.5 tons/day of PHA
• Application: Packaging for the local food chain
• Results:
  • 40% reduction in municipal wastewater treatment costs
  • 150 tons/year less of imported fossil plastic

SynBioWater Project (Germany-Netherlands)

• Technology: Modular reactors for SMEs
• Clients: 45 connected food industries
• Model: Payment for treated water + guaranteed purchase of PHA

Challenges Challenges and Solutions

Cross-Contamination

• Problem: Producer bacteria displaced by native species
• Solution: Continuous selection systems with controlled osmotic pressure

Extraction Cost

• Historical: 50-60% of the total PHA cost
• 2025: Methods using natural solvents (citrus limonene) reduce cost to 25%

Raw Material Variability

• Solution: Bacterial consortia adapted to different effluents
• Example: Halomonas boliviensis for industrial saline wastewater

Quantified Environmental Impact

Life Cycle Analysis

• For every kg of PHA produced:
  • 3.2 kg less CO₂ eq vs. petrochemical plastic
  • 45 liters of clean water generated
  • 0.8 kg less sludge for landfill

Potential Scalability

• Global urban wastewater: 330 km³/year
• Potential PHA production: 165 million tons/year
• Coverage: 45% of current global demand for plastics

Integration into Circular Economy

“Water-Plastic-Food” Model

• Food industry treats its wastewater
• Produces PHA for its own packaging
• Biodegradable packaging is composted after use
• Compost improves agricultural soils that produce food

Certifications Obtained

• OK compost INDUSTRIAL (TÜV Austria)
• Cradle to Cradle Certified®
• Reclaimed water for industrial use (UNE-EN 17075)

Future Trends 2026-2030

Programmable Bacteria

• Biological synthesis: Metabolic engineering for custom polymers
• Intracellular sensors: Activation only with specific contaminants
• Self-leaching: Spontaneous release of PHA at the end of the cycle

New Markets

• Biomedicine: Scaffolds for tissue regeneration
• Green electronics: Substrates for biodegradable circuits
• Precision agriculture: Microcapsules for controlled fertilizer release

How to Implement in Your Company or Municipalities

For Industrial SMEs

• Modular System: From 10 m³/day, investment €50,000-€100,000
• Return on Investment: 3-4 years (treatment savings + PHA sales)
• Subsidies: Up to 40% in EU circular economy programs

For Municipalities

• Integration with existing WWTP: Add-on module to conventional plant
• Hybrid Model: Municipal treatment + nearby industrial treatment
• Financing: Long-term PHA purchase agreements

Success Stories in Developing Countries

Nairobi Project (Kenya)

• Context: Municipal slaughterhouse with severe contamination
• Solution: Bacterial reactors + PHA production for medical devices
• Result:
  • Clean water for agricultural irrigation
  • 200 jobs at the processing plant
  • 90% reduction in waterborne diseases in the community

“We are teaching bacteria to do what they do best: transform waste into resources. Nature has spent millions of years perfecting this process; we just need to learn how to direct it.” — Dr. Sofia Chen, industrial biotechnologist.