Production, Optimization and Characterization of Serratia nematodiphila MB307 to Synthesize Polyhydroxybutyrate Using Wastewater in Submerged Fermentation

• Published in: International Journal of Environmental Research 2022-12, Vol.16 (6), Article 109
• Main Authors: Pervaiz, Maryam, Yasmin, Azra
• Format: Article
• Language: English
• Subjects: Acidic soils; Bacteria; Biodegradability; Biodegradation; Biopolymers; Biosynthesis; Carbon sources; Earth and Environmental Science; Environment; Environmental Engineering/Biotechnology; Environmental Management; Fermentation; Geoecology/Natural Processes; Glucose; Heavy metals; High-performance liquid chromatography; Industrial pollution; Landscape/Regional and Urban Planning; Liquid chromatography; Macromolecules; Metal industry wastewaters; Microorganisms; Natural Hazards; Optimization; Plastics; Polyester resins; Polyesters; Polyhydroxybutyrate; Polyhydroxybutyric acid; Polymers; Research Paper; Response surface methodology; Retention; Retention time; Sediment pollution; Serratia; Serratia nematodiphila; Simulation; Soil pollution; Substrates; Thermogravimetric analysis; Wastewater
• ISSN: 1735-6865; 2008-2304
• DOI: 10.1007/s41742-022-00487-6

Polyhydroxybutyrates (PHBs) are microbial polyesters having features resembling petroleum-based plastics thus termed as green plastics. Different species of bacteria evolving from diverse environments have shown the ability to produce these plastics with sustainable and environment friendly properties. In the current study potential of PHB accumulation was demonstrated by a biodegrading strain of Serratia nematodiphila MB307 for the first time using simulated wastewater as a substrate for submerged fermentation. Strain MB307 was isolated from polluted acidic soil of Hattar Industrial Estate, Haripur Pakistan. This is the first study showing 4.53 g/L PHB production using simulated wastewater and 4.8 g/L in the presence of glucose. Experimentally obtained optimum values of PHB production were further statistically endorsed by Response Surface Methodology which predicted PHB production as 4.31 g/L which is near to experimentally obtained data. Biopolymer characterization by FTIR revealed distinctive bands of PHB at 1726 cm −1 and 1732 cm −1 . GCMS chromatograms of polymer obtained from Serratia showed major peak of methyl ester of pentadecanoic acid at retention time of 24 min. HPLC analysis of the biopolymer depicted the retention time of PHB at 2.6 min. Thermogravimetric analysis showed that 80% of the polymer mass was lost at 346 °C, which depicts the thermostable nature of the polymer. Thus, this study highlighted the biodegradable polymer production from strain Serratia nematodiphila MB307. Strain MB307 has also depicted heavy metal tolerance and this feature was employed in this study as reported strain showed growth and metabolic potential in heavy metal composition of simulated wastewater. This study is important as it encompasses ‘trash to treasure’ phenomenon where wastewater was used and converted into valuable bioproduct PHB using microbial biosynthesis path. Graphical abstract Article Highlights PHB is an eco-friendly macromolecular biopolymer. Serratia nematodiphila MB307 showed PHB production utilizing wastewater and glucose as carbon source. 4.8 g/L PHB was produced from Serratia MB307 in this study, which was 64% of the cell dry mass. Characterization of the obtained polymer was done by HPLC, TGA, FTIR and GCMS.