Table 1.

Comparison of PHA production across different microbial strains

Strain	Type	Substrate	PHA Yield (% DCW)	Method/Condition	Scalability Challenges	References
Chlorella pyrenoidosa	Microalga	Glucose	27%	N-limitation + batch cultivation	Moderate yield, sensitive to contamination	Devadas et al. (2021)
Spirulina sp.	Cyanobacteria	Waste glycerol	12–22%	Salinity stress	Moderate scalability, requires pH control	Costa et al. (2020); Mourão et al. (2020)
Phaeodactylum tricornutum	Microalga	Sulfur-deprived media	10.6%	Photoperiod 14:10	Low productivity, expensive photobioreactors	Hempel et al. (2011)
Cupriavidus necator	Bacterium	Fructose, CO₂	~ 90%	Fed-batch fermentation	High yield, high substrate cost	Bellini et al. (2022)
Halomonas campaniensis	Marine Bacterium	Mixed fatty acids	60–70%	Non-sterile, saline environment	Needs halophilic reactor conditions	Yue et al. (2014)
Bacillus megaterium MNSH1-9 K-1	Bacterium	Fruit peel hydrolysates	52%	Open culture, enzymatic pretreatment	Variable carbon content in feedstock	Rivas-Castillo et al. (2024)
Chlorella fusca	Microalga	Pentose sugar	High (exact % not defined)	Static culture + gene upregulation	Slow growth, PHB recovery difficulty	Cassuriaga et al. (2018)
Pseudomonas putida KT2440	Bacterium	Fatty acids, glycerol	~ 65%	Accumulation reactor	Requires multi-stage processing	Le et al. (2012)
Synechococcus subsalsus	Cyanobacteria	Glucose under N-deficiency	16%	Controlled photobioreactor	Genetic tools still under development	Kartik et al. (2021)