Optimization of Physical Parameters Involved in Cell Lysis of Bacillus Sp. to Recover Bioplastic Polyhydroxyalkanoates

Abstract

Abstract The increased global population has concurrently increased waste disposal, whose majority is conventional plastic. In this study, polyhydroxyalkanoates (PHA), an alternative biopolymer to conventional plastics, were extracted from bacteria Bacillus sp., using response surface methodology (RSM), a statistical approach. To design, optimize and study the relationship between the parameters (glass beads weight, incubation time, water volume, incubation temperature, and shaker speed) Box-Behnken Design of response surface methodology was applied in Design Expert 10.0 software package. The solvent method is known in PHA extraction; however, this approach is environmentally hazardous on a large scale. The current study used a physical extraction method using glass beads for bacterial cell lysis. As a characterization, FTIR, 1HNMR, and DSC confirmed the recovered polymer as Polyhydroxy butyrate (PHB). 31.53% (w/v) of PHB was recovered for 1 g/L biomass. PHB is known to be widely applied in various fields, specifically in medical applications. Genetically modified isolate, low-cost substrate, and recovery without solvent assure a cost-effective and increased PHA production. Glass beads can be reused in extraction, reducing overall production cost. Therefore, this work used a reduced amount of chemicals during extraction to recover the PHB. Thus, sustainability assures a better scope for the future promotion of PHA production in academia and industries. Highlights Sustainable PHA extraction alternatives, reducing environmental impact, were studied. Glass beads are used to lyse the cell to release the PHA from the bacteria Bacillus sp. Box-Behnken design optimized extraction parameters for maximum recovery of PHA. The cellular lysis approach yields higher recovery than solvent-method recovery and is eco-friendly. Graphical abstract