Sustainable Polyhydroxyalkanoate Production from Food Waste via Bacillus mycoides ICRI89: Enhanced 3D Printing with Poly (Methyl Methacrylate) Blend

Abstract

In view of implementing green technologies for bioplastic turning polices, novel durable feedstock for Bacillus mycoides ICRI89 used for efficient polyhydroxybutyrate (PHB) generation is proposed herein. First, two food waste (FW) pretreatment methods were compared, where the ultrasonication approach for 7 min was effective in easing the following enzymatic action. After treatment with a mixture of cellulase/amylases, an impressive 25.3 ± 0.22 g/L of glucose was liberated per 50 g of FW. Furthermore, a notable 2.11 ± 0.06 g/L PHB and 3.56 ± 0.11 g/L cell dry eight (CDW) over 120 h were generated, representing a productivity percentage of 59.3 wt% using 25% FW hydrolysate. The blend of polyhydroxybutyrate/poly (methyl methacrylate) (PHB/PMMA = 1:2) possessed the most satisfactory mechanical properties. For the first time, PHB was chemically crosslinked with PMMA using dicumyl peroxide (DCP), where a concentration of 0.3 wt% had a considerable effect on increasing the mechanical stability of the blend. FTIR analysis confirmed the molecular interaction between PHB and PMMA showing a modest expansion of the C=O stretching vibration at 1725 cm−1. The DCP-PHB/PMMA blend had significant thermal stability and biodegradation profiles comparable to those of the main constituent polymers. More importantly, a 3-Dimetional (3D) filament was successfully extruded with a diameter of 1.75 mm, where no blockages or air bubbles were noticed via SEM. A new PHB/PMMA “key of life” 3D model has been printed with a filling percentage of 60% and a short printing time of 19.2 min. To conclude, high-performance polymeric 3D models have been fabricated to meet the pressing demands for future applications of sustainable polymers.