Unlocking sustainable solutions: wood waste as a novel substrate for polyhydroxybutyrate (PHB) production to combat plastic pollution

Abstract

Polyhydroxybutyrate (PHB) is considered as a hope for bioplastic production, which can serve as a sustainable alternative. Utilizing feedstock as substrate is widely explored for the production but wood waste, which is abundant in cellulose, hemicellulose and lignocellulose, has limited studies for PHB production. Herein, wood waste is used as a biobased feedstock Hydrolyses of wood waste was done using sulphuric acid (H₂SO₄) to break down of cellulose and hemicellulose into simple carbon forms. The hydrolysed product was analysed for sugar presence by quantitative and qualitative methods. Pseudomonas fluorescens bacterial strain was used for the production purpose using hydrolysed wood waste as substrate media. The Plackett-Burman design (PBD) and response surface methodology (RSM) were applied to optimize the growth media. The results of PBD were used to identify significant factors influencing PHB production, which were then further optimized using RSM. The work's results conclusively demonstrated that P. fluorescens possesses the capability to effectively utilize wood waste and wastewater as substrate media up to production rate of 13-14 mg mL^-1 of PHB. Fourier Transformed Infra-Red (FTIR) spectroscopic peaks confirm the produced product is PHB, which is a type of polyhydroxyalkanoate (PHA), classified within the polyester family highlighting wood waste potential as a sustainable solution to address plastic pollution.

Keywords: Plackett-Burman design; Polyhydroxyalkanoate; Pseudomonas fluorescens; polyhydroxybutyrate; wood waste.