Polystyrene microplastic degradation by a novel PGPR Bacillus spizizenii.

This study explores the novel use of Plant Growth Promoting Rhizobacteria, Bacillus spizizenii as a Polystyrene Microplastic (PS-MP) degrading agent. An impressive 85.86 % MP degradation efficiency was reported over a span of 30 days when Polystyrene (PS) was used as an exclusive carbon source. Fourier transform infrared spectroscopy (FTIR) confirmed the significant alteration in PS-MP peak intensities, indicating the breakdown of PS. Further, PS surface degradation was clearly visible in scanning electron microscopy (SEM) imaging. The metabolic analyses were performed after 30 days using Gas Chromatography-Mass Spectrometry (GC-MS). Using these metabolic data references in the KEGG database of Bacillus spizizenii potential degradation pathways were outlined. The PGPR traits of Bacillus spizizenii were confirmed by Indole Acetic Acid (IAA) Production, Phosphate solubilization, Ammonia, Hydrogen Cyanide (HCN), and Siderophore production. The results provide a novel candidate for PS degradation. The PGPR qualities further make it feasible for the use of plastic-polluted soil restoration.