Lignocellulosic biomass (LCB): a potential alternative biorefinery feedstock for polyhydroxyalkanoates production

Polyhydroxyalkanoates (PHAs) are one of the most promising, degradable and eco-friendly alternatives to fossil fuel-based plastic. Nevertheless, PHA derived from edible sources is a relatively easier process than using other resources. Cost of raw material is being considered as a significant constraint for sustainability of industrial bioplastic production. In recent days, lignocellulosic biomass (LCB) in the form of waste residue generated from agriculture, forestry, energy crop system, marine biomass, industrial and municipal solid waste has gained great attention as it is the most abundant feedstock worldwide and supports the sustainable production of PHA. However, the conversion efficiency and PHA yield vary significantly based on the source and nature of LCB due to their content distinction. The complex structure of LCB, mainly composed of cellulose, hemicellulose, and lignin, makes it challenging to be depolymerized. Therefore, the processes required to utilize LCB for production of PHA are covered in this review including pretreatment, hydrolysis, fermentation, and the associated difficulties during the process development. In addition, several attempts made to exploit LCB as a feedstock for PHA production were also discussed in order to improve the overall conversion process.