Thermally Stable P(3HB) Synthesis from Cane Molasses by Co-culture of Alcaligenes sp. NCIM 5085 and Bacillus subtilis

The co-culture approach has been discovered to be more efficient over isolated in carbon uptake, growth of bacteria and Poly(3-hydroxybutyrete) (P(3HB)) productivity. The current study focused on synthesis of P(3HB) from a co-culture of Alcaligenes sp. NCIM 5085 and Bacillus subtilis sand characterizing the recovered P(3HB) for better packaging applications. The enzymatic reactions mechanism possible was identified. The obtained P(3HB) was structurally analyzed using GCMS, FTIR, ¹HNMR and ¹³CNMR. The peak observed at 1720.06 cm⁻¹ on FTIR spectra indicates the existence of the C=O group, that is a defined marker of P(3HB). Subsequent NMR and GCMS investigation verified that the obtained polymer is P(3HB). The DSC analysis revealed the melting point (T_melt), crystallization temperature (T_c) and glass transient temperature (T_g) of polymer 172.5 °C, 100 °C and − 6.8 °C, respectively, which are within the normal P(3HB) range. The TGA- DTG indicated the thermal degradation temperature (T_degr) of synthesized P(3HB) was 254.5 °C and major weight loss was observed between 180 and 300 °C. As a result, it can be established that the synthesized P(3HB) seems to be more resistant to thermal degradation than the conventional P(3HB). The investigation imply that developing a bacteria co-culture technique seems to be a potential approach for such effective synthesis of valuable biopolymers from agricultural waste.