Likelihood of polyhydroxyalkanoates production using canola oil cake and specific bacterial isolates for eco-friendly...

Polyhydroxyalkanoates (PHA) are a suitable replacement for conventional petroleum plastics. The global push for environmentally friendly plastics is driving research into innovative, sustainable solutions. This study emphasizes enhancing the production and properties of PHA by using consortia comprising known bacterial strains grown in a glucose-rich, peptone-deficient (GRPD) medium supplemented with 1% canola oil cake as a renewable carbon source. The addition of canola oil cake as an additive accelerated the growth by increasing biomass by 74.22% and simultaneously boosted the PHA yield by 68.67%. Employing confocal microscopy, the PHA granules within the bacterial cells were visualised. Chemical fingerprinting of the PHA film using Fourier transform infrared spectroscopy (FTIR) displayed unique functional groups - carbonyl (-CO-) and ester (-COO-) - at an explicit peak of 1718 cm^-1, demonstrating that the polymer was polyhydroxybutyrate (PHB), for Bacillus cereus strain ST001 and Enterobacter cloacae strain AP001; however Rhodococcus ruber strain TESIII revealed a peak at 1653 cm^-1 implying the existence of methylene (-CH-). The resultant PHA was identified as poly(3-hydroxybutyrate-co-hydroxyvalerate) [PHBV]. Significant results were documented. A tensile strength of 0.13 MPa and a thermal degradation temperature of 240-260 °C were demonstrated by the resulting PHA. It was further recorded that there was an increase in the intensity of 76.92% of tensile strength in PHA samples when bacteria were cultured in GRPD supplemented with the renewable carbon source. These findings explain the potential of canola oil cake as a cost-effective, renewable feedstock additive for enhancing PHA production and material quality, thus paving the way for future advancements in sustainable bioplastic development.