The Promises and Problems of Using Bacteria Against Plastic

The Promises and Problems of Using Bacteria Against Plastic

Sub : Env

Sec: Pollution

Introduction

• Plastic waste crisis has driven biologists to find sustainable solutions using bacteria and enzymes for degradation.
• Scientists and companies are researching, innovating, and commercializing these solutions.
• Challenges include scalability, efficiency, and industry adoption.

Challenges in Plastic Waste

• Plastic is hard to degrade and persists in the environment for centuries.
• Since large-scale plastic production began 65 years ago, about 8.3 billion tonnes have been produced.
• Only less than 10% has been recycled, while around 4.9 billion tonnes remain in the environment.

Microbial Solutions to Plastic Degradation

Enzyme-Based Approach

• Scientists have engineered enzymes to break down PET (Polyethylene Terephthalate) plastic.
• Kōhei Oda’s team discovered an enzyme in 2016, IsPETase, which breaks PET down slowly.
• Advancements in enzyme engineering now allow 90% degradation of PET in just 17 hours into reusable monomers like terephthalic acid and ethylene glycol.
• Challenges:
  • Increasing speed and efficiency of enzyme degradation.
  • Reducing costs for large-scale industrial applications.

Microbial Degradation Approach

• Scientists are also working on microbial solutions where bacteria directly consume plastics.
• Example: A bacterium named X-32 takes around 22 months to break down plastics into CO₂, water, and biomass.
• Key Process:

1. Microbial attachment to plastic surfaces.
2. Microbes use plastic as a carbon source for energy.
3. Polymer breakdown through enzyme secretion.

• Challenges:
  • Slow degradation rate compared to enzyme-based methods.
  • Needs optimization for industrial scalability.

The Biological Approach: Spore-Based Biodegradable Plastic

• Researchers at Harvard and Wyss Institute have developed a bacteria-based thermoplastic.
• Process:
  • Heat-resistant bacterial spores (Bacillus subtilis) are embedded in plastic.
  • Spores remain dormant in normal conditions but activate in composting environments.
  • They reinforce plastic structure and eventually help degrade it.
• Advantages:
  • Enhances durability of plastic when in use.
  • Degrades faster in composting conditions.
  • Industry-friendly alternative.
• Challenges:
  • Regulatory approval concerns for consumer products.
  • Scaling up spore purification for mass production.

Industry Adoption and Challenges

• Companies and researchers working on making bacterial and enzymatic plastic degradation industrially viable.

Example:

• Carbios (French company) developed a PET-digesting enzyme that breaks down plastic in 10 hours.
• North Carolina’s biomaterial companies are testing thermoplastics with spores for biodegradability.
• Scaling remains a major hurdle, as commercial production requires:
  • Higher efficiency in degradation.
  • Lower costs for enzyme purification.
  • Industries willing to adopt the technology.

Conclusion

• Bacteria and enzymes offer potential solutions to plastic waste.
• Research advancements are promising, but scalability, efficiency, and industry adoption remain major challenges.
• Future efforts should focus on enhancing enzymatic processes, developing microbial solutions, and ensuring commercial feasibility.