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:

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.