Biowaste-to-bioplastic (polyhydroxyalkanoates): Conversion technologies, strategies, challenges, and perspective

Area of Science:

• Environmental Science
• Biotechnology
• Materials Science

Background:

• Biowaste presents significant disposal challenges due to its nutrient content, posing environmental and health risks.
• Traditional biowaste management methods like landfilling, bio-composting, and incineration have limitations.
• There is a growing global focus on valorizing biowaste into commercial products, including volatile fatty acids (VFA), biohydrogen, and bioplastics.

Purpose of the Study:

• To review recent advancements in polyhydroxyalkanoates (PHA) production from various biowaste streams.
• To summarize downstream processing techniques for PHA.
• To identify challenges and opportunities in making bioplastics a viable alternative to synthetic plastics.

Main Methods:

• Review of scientific literature on biowaste valorization for PHA production.
• Analysis of studies focusing on different biowaste feedstocks (lignocellulosic biomass, municipal waste, waste cooking oils, biodiesel industry waste, syngas).
• Examination of critical factors influencing PHA production, such as carbon/nitrogen sources and dissolved oxygen levels.

Main Results:

• Successful PHA production has been demonstrated from a wide array of biowastes.
• Key nutrient factors, including carbon and nitrogen concentrations and dissolved oxygen availability, are crucial for optimizing PHA yields.
• Various downstream processing methods are employed for PHA recovery and purification.

Conclusions:

• Biowaste represents a promising and sustainable feedstock for the production of polyhydroxyalkanoates (PHA).
• Optimizing nutrient factors and downstream processing is essential for efficient and cost-effective bioplastic production.
• Overcoming current challenges can establish bioplastics as a competitive alternative to conventional synthetic plastics.