Table 2.

comparative assessment of Biopolymer feedstock based on sustainability and productivity and limitations

Feedstock	Biopolymer Types	Land/Water Use	Productivity (Yield %)	CO₂ Sequestration	Energy Demand	Cost Efficiency	Key Limitations	References
Algal Biomass	PHA, PLA, Starch, Alginates, Cellulose	Non-arable, saline/wastewater	10–35% DCW; up to 4 g/L/day (Chlorella, Spirulina)	High	Moderate (drying, harvesting)	Improving with biorefineries	High moisture content; scale-up challenges	Mohan et al. (2022); Vickram et al. (2023)
Lignocellulosic Waste	PLA, PHA (via bacterial processing)	High; forestry and crop residues	10–40% (after pretreatment)	Low	High (due to recalcitrance)	Low but feedstock is abundant	Expensive pretreatment; lignin interference	Goswami et al. (2022)
Bacterial Fermentation	PHA (e.g., PHB, PHV), PLA	Indirect (sugar/starch-based feed)	Up to 90% CDW (Cupriavidus necator, Ralstonia eutropha)	Low	High (sterile conditions)	Moderate–High (depends on substrate)	Requires sugars; energy and maintenance intensive	Arora et al. (2023); Bellini et al. (2022)
Food Waste/Glycerol	PHA, Starch blends	Low; uses existing waste streams	15–50% (B. megaterium, Pseudomonas putida)	Medium	Moderate	High in circular systems	Variable composition and regulatory barriers	Rivas-Castillo et al. (2024)